fs/ext4/super.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/ext4/super.c
   4  *
   5  * Copyright (C) 1992, 1993, 1994, 1995
   6  * Remy Card (card@masi.ibp.fr)
   7  * Laboratoire MASI - Institut Blaise Pascal
   8  * Universite Pierre et Marie Curie (Paris VI)
   9  *
  10  *  from
  11  *
  12  *  linux/fs/minix/inode.c
  13  *
  14  *  Copyright (C) 1991, 1992  Linus Torvalds
  15  *
  16  *  Big-endian to little-endian byte-swapping/bitmaps by
  17  *        David S. Miller (davem@caip.rutgers.edu), 1995
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/string.h>
  22 #include <linux/fs.h>
  23 #include <linux/time.h>
  24 #include <linux/vmalloc.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/backing-dev.h>
  29 #include <linux/parser.h>
  30 #include <linux/buffer_head.h>
  31 #include <linux/exportfs.h>
  32 #include <linux/vfs.h>
  33 #include <linux/random.h>
  34 #include <linux/mount.h>
  35 #include <linux/namei.h>
  36 #include <linux/quotaops.h>
  37 #include <linux/seq_file.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <linux/dax.h>
  42 #include <linux/cleancache.h>
  43 #include <linux/uaccess.h>
  44 #include <linux/iversion.h>
  45 #include <linux/unicode.h>
  46 #include <linux/part_stat.h>
  47 #include <linux/kthread.h>
  48 #include <linux/freezer.h>
  49 #include <linux/fsnotify.h>
  50 #include <linux/fs_context.h>
  51 #include <linux/fs_parser.h>
  52
  53 #include "ext4.h"
  54 #include "ext4_extents.h"       /* Needed for trace points definition */
  55 #include "ext4_jbd2.h"
  56 #include "xattr.h"
  57 #include "acl.h"
  58 #include "mballoc.h"
  59 #include "fsmap.h"
  60
  61 #define CREATE_TRACE_POINTS
  62 #include <trace/events/ext4.h>
  63
  64 static struct ext4_lazy_init *ext4_li_info;
  65 static DEFINE_MUTEX(ext4_li_mtx);
  66 static struct ratelimit_state ext4_mount_msg_ratelimit;
  67
  68 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  69                              unsigned long journal_devnum);
  70 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  71 static void ext4_update_super(struct super_block *sb);
  72 static int ext4_commit_super(struct super_block *sb);
  73 static int ext4_mark_recovery_complete(struct super_block *sb,
  74                                         struct ext4_super_block *es);
  75 static int ext4_clear_journal_err(struct super_block *sb,
  76                                   struct ext4_super_block *es);
  77 static int ext4_sync_fs(struct super_block *sb, int wait);
  78 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  79 static int ext4_unfreeze(struct super_block *sb);
  80 static int ext4_freeze(struct super_block *sb);
  81 static inline int ext2_feature_set_ok(struct super_block *sb);
  82 static inline int ext3_feature_set_ok(struct super_block *sb);
  83 static void ext4_destroy_lazyinit_thread(void);
  84 static void ext4_unregister_li_request(struct super_block *sb);
  85 static void ext4_clear_request_list(void);
  86 static struct inode *ext4_get_journal_inode(struct super_block *sb,
  87                                             unsigned int journal_inum);
  88 static int ext4_validate_options(struct fs_context *fc);
  89 static int ext4_check_opt_consistency(struct fs_context *fc,
  90                                       struct super_block *sb);
  91 static int ext4_apply_options(struct fs_context *fc, struct super_block *sb);
  92 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
  93 static int ext4_get_tree(struct fs_context *fc);
  94 static int ext4_reconfigure(struct fs_context *fc);
  95 static void ext4_fc_free(struct fs_context *fc);
  96 static int ext4_init_fs_context(struct fs_context *fc);
  97 static const struct fs_parameter_spec ext4_param_specs[];
  98
  99 /*
 100  * Lock ordering
 101  *
 102  * page fault path:
 103  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
 104  *   -> page lock -> i_data_sem (rw)
 105  *
 106  * buffered write path:
 107  * sb_start_write -> i_mutex -> mmap_lock
 108  * sb_start_write -> i_mutex -> transaction start -> page lock ->
 109  *   i_data_sem (rw)
 110  *
 111  * truncate:
 112  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
 113  *   page lock
 114  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
 115  *   i_data_sem (rw)
 116  *
 117  * direct IO:
 118  * sb_start_write -> i_mutex -> mmap_lock
 119  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
 120  *
 121  * writepages:
 122  * transaction start -> page lock(s) -> i_data_sem (rw)
 123  */
 124
 125 static const struct fs_context_operations ext4_context_ops = {
 126         .parse_param    = ext4_parse_param,
 127         .get_tree       = ext4_get_tree,
 128         .reconfigure    = ext4_reconfigure,
 129         .free           = ext4_fc_free,
 130 };
 131
 132
 133 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 134 static struct file_system_type ext2_fs_type = {
 135         .owner                  = THIS_MODULE,
 136         .name                   = "ext2",
 137         .init_fs_context        = ext4_init_fs_context,
 138         .parameters             = ext4_param_specs,
 139         .kill_sb                = kill_block_super,
 140         .fs_flags               = FS_REQUIRES_DEV,
 141 };
 142 MODULE_ALIAS_FS("ext2");
 143 MODULE_ALIAS("ext2");
 144 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 145 #else
 146 #define IS_EXT2_SB(sb) (0)
 147 #endif
 148
 149
 150 static struct file_system_type ext3_fs_type = {
 151         .owner                  = THIS_MODULE,
 152         .name                   = "ext3",
 153         .init_fs_context        = ext4_init_fs_context,
 154         .parameters             = ext4_param_specs,
 155         .kill_sb                = kill_block_super,
 156         .fs_flags               = FS_REQUIRES_DEV,
 157 };
 158 MODULE_ALIAS_FS("ext3");
 159 MODULE_ALIAS("ext3");
 160 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 161
 162
 163 static inline void __ext4_read_bh(struct buffer_head *bh, int op_flags,
 164                                   bh_end_io_t *end_io)
 165 {
 166         /*
 167          * buffer's verified bit is no longer valid after reading from
 168          * disk again due to write out error, clear it to make sure we
 169          * recheck the buffer contents.
 170          */
 171         clear_buffer_verified(bh);
 172
 173         bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
 174         get_bh(bh);
 175         submit_bh(REQ_OP_READ, op_flags, bh);
 176 }
 177
 178 void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags,
 179                          bh_end_io_t *end_io)
 180 {
 181         BUG_ON(!buffer_locked(bh));
 182
 183         if (ext4_buffer_uptodate(bh)) {
 184                 unlock_buffer(bh);
 185                 return;
 186         }
 187         __ext4_read_bh(bh, op_flags, end_io);
 188 }
 189
 190 int ext4_read_bh(struct buffer_head *bh, int op_flags, bh_end_io_t *end_io)
 191 {
 192         BUG_ON(!buffer_locked(bh));
 193
 194         if (ext4_buffer_uptodate(bh)) {
 195                 unlock_buffer(bh);
 196                 return 0;
 197         }
 198
 199         __ext4_read_bh(bh, op_flags, end_io);
 200
 201         wait_on_buffer(bh);
 202         if (buffer_uptodate(bh))
 203                 return 0;
 204         return -EIO;
 205 }
 206
 207 int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait)
 208 {
 209         if (trylock_buffer(bh)) {
 210                 if (wait)
 211                         return ext4_read_bh(bh, op_flags, NULL);
 212                 ext4_read_bh_nowait(bh, op_flags, NULL);
 213                 return 0;
 214         }
 215         if (wait) {
 216                 wait_on_buffer(bh);
 217                 if (buffer_uptodate(bh))
 218                         return 0;
 219                 return -EIO;
 220         }
 221         return 0;
 222 }
 223
 224 /*
 225  * This works like __bread_gfp() except it uses ERR_PTR for error
 226  * returns.  Currently with sb_bread it's impossible to distinguish
 227  * between ENOMEM and EIO situations (since both result in a NULL
 228  * return.
 229  */
 230 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
 231                                                sector_t block, int op_flags,
 232                                                gfp_t gfp)
 233 {
 234         struct buffer_head *bh;
 235         int ret;
 236
 237         bh = sb_getblk_gfp(sb, block, gfp);
 238         if (bh == NULL)
 239                 return ERR_PTR(-ENOMEM);
 240         if (ext4_buffer_uptodate(bh))
 241                 return bh;
 242
 243         ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
 244         if (ret) {
 245                 put_bh(bh);
 246                 return ERR_PTR(ret);
 247         }
 248         return bh;
 249 }
 250
 251 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
 252                                    int op_flags)
 253 {
 254         return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
 255 }
 256
 257 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
 258                                             sector_t block)
 259 {
 260         return __ext4_sb_bread_gfp(sb, block, 0, 0);
 261 }
 262
 263 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
 264 {
 265         struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
 266
 267         if (likely(bh)) {
 268                 ext4_read_bh_lock(bh, REQ_RAHEAD, false);
 269                 brelse(bh);
 270         }
 271 }
 272
 273 static int ext4_verify_csum_type(struct super_block *sb,
 274                                  struct ext4_super_block *es)
 275 {
 276         if (!ext4_has_feature_metadata_csum(sb))
 277                 return 1;
 278
 279         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 280 }
 281
 282 static __le32 ext4_superblock_csum(struct super_block *sb,
 283                                    struct ext4_super_block *es)
 284 {
 285         struct ext4_sb_info *sbi = EXT4_SB(sb);
 286         int offset = offsetof(struct ext4_super_block, s_checksum);
 287         __u32 csum;
 288
 289         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 290
 291         return cpu_to_le32(csum);
 292 }
 293
 294 static int ext4_superblock_csum_verify(struct super_block *sb,
 295                                        struct ext4_super_block *es)
 296 {
 297         if (!ext4_has_metadata_csum(sb))
 298                 return 1;
 299
 300         return es->s_checksum == ext4_superblock_csum(sb, es);
 301 }
 302
 303 void ext4_superblock_csum_set(struct super_block *sb)
 304 {
 305         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 306
 307         if (!ext4_has_metadata_csum(sb))
 308                 return;
 309
 310         es->s_checksum = ext4_superblock_csum(sb, es);
 311 }
 312
 313 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 314                                struct ext4_group_desc *bg)
 315 {
 316         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 317                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 318                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 319 }
 320
 321 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 322                                struct ext4_group_desc *bg)
 323 {
 324         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 325                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 326                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 327 }
 328
 329 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 330                               struct ext4_group_desc *bg)
 331 {
 332         return le32_to_cpu(bg->bg_inode_table_lo) |
 333                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 334                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 335 }
 336
 337 __u32 ext4_free_group_clusters(struct super_block *sb,
 338                                struct ext4_group_desc *bg)
 339 {
 340         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 341                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 342                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 343 }
 344
 345 __u32 ext4_free_inodes_count(struct super_block *sb,
 346                               struct ext4_group_desc *bg)
 347 {
 348         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 349                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 350                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 351 }
 352
 353 __u32 ext4_used_dirs_count(struct super_block *sb,
 354                               struct ext4_group_desc *bg)
 355 {
 356         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 357                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 358                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 359 }
 360
 361 __u32 ext4_itable_unused_count(struct super_block *sb,
 362                               struct ext4_group_desc *bg)
 363 {
 364         return le16_to_cpu(bg->bg_itable_unused_lo) |
 365                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 366                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 367 }
 368
 369 void ext4_block_bitmap_set(struct super_block *sb,
 370                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 371 {
 372         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 373         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 374                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 375 }
 376
 377 void ext4_inode_bitmap_set(struct super_block *sb,
 378                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 379 {
 380         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 381         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 382                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 383 }
 384
 385 void ext4_inode_table_set(struct super_block *sb,
 386                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 387 {
 388         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 389         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 390                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 391 }
 392
 393 void ext4_free_group_clusters_set(struct super_block *sb,
 394                                   struct ext4_group_desc *bg, __u32 count)
 395 {
 396         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 397         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 398                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 399 }
 400
 401 void ext4_free_inodes_set(struct super_block *sb,
 402                           struct ext4_group_desc *bg, __u32 count)
 403 {
 404         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 405         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 406                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 407 }
 408
 409 void ext4_used_dirs_set(struct super_block *sb,
 410                           struct ext4_group_desc *bg, __u32 count)
 411 {
 412         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 413         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 414                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 415 }
 416
 417 void ext4_itable_unused_set(struct super_block *sb,
 418                           struct ext4_group_desc *bg, __u32 count)
 419 {
 420         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 421         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 422                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 423 }
 424
 425 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
 426 {
 427         now = clamp_val(now, 0, (1ull << 40) - 1);
 428
 429         *lo = cpu_to_le32(lower_32_bits(now));
 430         *hi = upper_32_bits(now);
 431 }
 432
 433 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
 434 {
 435         return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
 436 }
 437 #define ext4_update_tstamp(es, tstamp) \
 438         __ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
 439                              ktime_get_real_seconds())
 440 #define ext4_get_tstamp(es, tstamp) \
 441         __ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
 442
 443 /*
 444  * The del_gendisk() function uninitializes the disk-specific data
 445  * structures, including the bdi structure, without telling anyone
 446  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 447  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 448  * This is a kludge to prevent these oops until we can put in a proper
 449  * hook in del_gendisk() to inform the VFS and file system layers.
 450  */
 451 static int block_device_ejected(struct super_block *sb)
 452 {
 453         struct inode *bd_inode = sb->s_bdev->bd_inode;
 454         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 455
 456         return bdi->dev == NULL;
 457 }
 458
 459 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 460 {
 461         struct super_block              *sb = journal->j_private;
 462         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 463         int                             error = is_journal_aborted(journal);
 464         struct ext4_journal_cb_entry    *jce;
 465
 466         BUG_ON(txn->t_state == T_FINISHED);
 467
 468         ext4_process_freed_data(sb, txn->t_tid);
 469
 470         spin_lock(&sbi->s_md_lock);
 471         while (!list_empty(&txn->t_private_list)) {
 472                 jce = list_entry(txn->t_private_list.next,
 473                                  struct ext4_journal_cb_entry, jce_list);
 474                 list_del_init(&jce->jce_list);
 475                 spin_unlock(&sbi->s_md_lock);
 476                 jce->jce_func(sb, jce, error);
 477                 spin_lock(&sbi->s_md_lock);
 478         }
 479         spin_unlock(&sbi->s_md_lock);
 480 }
 481
 482 /*
 483  * This writepage callback for write_cache_pages()
 484  * takes care of a few cases after page cleaning.
 485  *
 486  * write_cache_pages() already checks for dirty pages
 487  * and calls clear_page_dirty_for_io(), which we want,
 488  * to write protect the pages.
 489  *
 490  * However, we may have to redirty a page (see below.)
 491  */
 492 static int ext4_journalled_writepage_callback(struct page *page,
 493                                               struct writeback_control *wbc,
 494                                               void *data)
 495 {
 496         transaction_t *transaction = (transaction_t *) data;
 497         struct buffer_head *bh, *head;
 498         struct journal_head *jh;
 499
 500         bh = head = page_buffers(page);
 501         do {
 502                 /*
 503                  * We have to redirty a page in these cases:
 504                  * 1) If buffer is dirty, it means the page was dirty because it
 505                  * contains a buffer that needs checkpointing. So the dirty bit
 506                  * needs to be preserved so that checkpointing writes the buffer
 507                  * properly.
 508                  * 2) If buffer is not part of the committing transaction
 509                  * (we may have just accidentally come across this buffer because
 510                  * inode range tracking is not exact) or if the currently running
 511                  * transaction already contains this buffer as well, dirty bit
 512                  * needs to be preserved so that the buffer gets writeprotected
 513                  * properly on running transaction's commit.
 514                  */
 515                 jh = bh2jh(bh);
 516                 if (buffer_dirty(bh) ||
 517                     (jh && (jh->b_transaction != transaction ||
 518                             jh->b_next_transaction))) {
 519                         redirty_page_for_writepage(wbc, page);
 520                         goto out;
 521                 }
 522         } while ((bh = bh->b_this_page) != head);
 523
 524 out:
 525         return AOP_WRITEPAGE_ACTIVATE;
 526 }
 527
 528 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
 529 {
 530         struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
 531         struct writeback_control wbc = {
 532                 .sync_mode =  WB_SYNC_ALL,
 533                 .nr_to_write = LONG_MAX,
 534                 .range_start = jinode->i_dirty_start,
 535                 .range_end = jinode->i_dirty_end,
 536         };
 537
 538         return write_cache_pages(mapping, &wbc,
 539                                  ext4_journalled_writepage_callback,
 540                                  jinode->i_transaction);
 541 }
 542
 543 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
 544 {
 545         int ret;
 546
 547         if (ext4_should_journal_data(jinode->i_vfs_inode))
 548                 ret = ext4_journalled_submit_inode_data_buffers(jinode);
 549         else
 550                 ret = jbd2_journal_submit_inode_data_buffers(jinode);
 551
 552         return ret;
 553 }
 554
 555 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
 556 {
 557         int ret = 0;
 558
 559         if (!ext4_should_journal_data(jinode->i_vfs_inode))
 560                 ret = jbd2_journal_finish_inode_data_buffers(jinode);
 561
 562         return ret;
 563 }
 564
 565 static bool system_going_down(void)
 566 {
 567         return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
 568                 || system_state == SYSTEM_RESTART;
 569 }
 570
 571 struct ext4_err_translation {
 572         int code;
 573         int errno;
 574 };
 575
 576 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
 577
 578 static struct ext4_err_translation err_translation[] = {
 579         EXT4_ERR_TRANSLATE(EIO),
 580         EXT4_ERR_TRANSLATE(ENOMEM),
 581         EXT4_ERR_TRANSLATE(EFSBADCRC),
 582         EXT4_ERR_TRANSLATE(EFSCORRUPTED),
 583         EXT4_ERR_TRANSLATE(ENOSPC),
 584         EXT4_ERR_TRANSLATE(ENOKEY),
 585         EXT4_ERR_TRANSLATE(EROFS),
 586         EXT4_ERR_TRANSLATE(EFBIG),
 587         EXT4_ERR_TRANSLATE(EEXIST),
 588         EXT4_ERR_TRANSLATE(ERANGE),
 589         EXT4_ERR_TRANSLATE(EOVERFLOW),
 590         EXT4_ERR_TRANSLATE(EBUSY),
 591         EXT4_ERR_TRANSLATE(ENOTDIR),
 592         EXT4_ERR_TRANSLATE(ENOTEMPTY),
 593         EXT4_ERR_TRANSLATE(ESHUTDOWN),
 594         EXT4_ERR_TRANSLATE(EFAULT),
 595 };
 596
 597 static int ext4_errno_to_code(int errno)
 598 {
 599         int i;
 600
 601         for (i = 0; i < ARRAY_SIZE(err_translation); i++)
 602                 if (err_translation[i].errno == errno)
 603                         return err_translation[i].code;
 604         return EXT4_ERR_UNKNOWN;
 605 }
 606
 607 static void save_error_info(struct super_block *sb, int error,
 608                             __u32 ino, __u64 block,
 609                             const char *func, unsigned int line)
 610 {
 611         struct ext4_sb_info *sbi = EXT4_SB(sb);
 612
 613         /* We default to EFSCORRUPTED error... */
 614         if (error == 0)
 615                 error = EFSCORRUPTED;
 616
 617         spin_lock(&sbi->s_error_lock);
 618         sbi->s_add_error_count++;
 619         sbi->s_last_error_code = error;
 620         sbi->s_last_error_line = line;
 621         sbi->s_last_error_ino = ino;
 622         sbi->s_last_error_block = block;
 623         sbi->s_last_error_func = func;
 624         sbi->s_last_error_time = ktime_get_real_seconds();
 625         if (!sbi->s_first_error_time) {
 626                 sbi->s_first_error_code = error;
 627                 sbi->s_first_error_line = line;
 628                 sbi->s_first_error_ino = ino;
 629                 sbi->s_first_error_block = block;
 630                 sbi->s_first_error_func = func;
 631                 sbi->s_first_error_time = sbi->s_last_error_time;
 632         }
 633         spin_unlock(&sbi->s_error_lock);
 634 }
 635
 636 /* Deal with the reporting of failure conditions on a filesystem such as
 637  * inconsistencies detected or read IO failures.
 638  *
 639  * On ext2, we can store the error state of the filesystem in the
 640  * superblock.  That is not possible on ext4, because we may have other
 641  * write ordering constraints on the superblock which prevent us from
 642  * writing it out straight away; and given that the journal is about to
 643  * be aborted, we can't rely on the current, or future, transactions to
 644  * write out the superblock safely.
 645  *
 646  * We'll just use the jbd2_journal_abort() error code to record an error in
 647  * the journal instead.  On recovery, the journal will complain about
 648  * that error until we've noted it down and cleared it.
 649  *
 650  * If force_ro is set, we unconditionally force the filesystem into an
 651  * ABORT|READONLY state, unless the error response on the fs has been set to
 652  * panic in which case we take the easy way out and panic immediately. This is
 653  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
 654  * at a critical moment in log management.
 655  */
 656 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
 657                               __u32 ino, __u64 block,
 658                               const char *func, unsigned int line)
 659 {
 660         journal_t *journal = EXT4_SB(sb)->s_journal;
 661         bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
 662
 663         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 664         if (test_opt(sb, WARN_ON_ERROR))
 665                 WARN_ON_ONCE(1);
 666
 667         if (!continue_fs && !sb_rdonly(sb)) {
 668                 ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
 669                 if (journal)
 670                         jbd2_journal_abort(journal, -EIO);
 671         }
 672
 673         if (!bdev_read_only(sb->s_bdev)) {
 674                 save_error_info(sb, error, ino, block, func, line);
 675                 /*
 676                  * In case the fs should keep running, we need to writeout
 677                  * superblock through the journal. Due to lock ordering
 678                  * constraints, it may not be safe to do it right here so we
 679                  * defer superblock flushing to a workqueue.
 680                  */
 681                 if (continue_fs && journal)
 682                         schedule_work(&EXT4_SB(sb)->s_error_work);
 683                 else
 684                         ext4_commit_super(sb);
 685         }
 686
 687         /*
 688          * We force ERRORS_RO behavior when system is rebooting. Otherwise we
 689          * could panic during 'reboot -f' as the underlying device got already
 690          * disabled.
 691          */
 692         if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
 693                 panic("EXT4-fs (device %s): panic forced after error\n",
 694                         sb->s_id);
 695         }
 696
 697         if (sb_rdonly(sb) || continue_fs)
 698                 return;
 699
 700         ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 701         /*
 702          * Make sure updated value of ->s_mount_flags will be visible before
 703          * ->s_flags update
 704          */
 705         smp_wmb();
 706         sb->s_flags |= SB_RDONLY;
 707 }
 708
 709 static void flush_stashed_error_work(struct work_struct *work)
 710 {
 711         struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
 712                                                 s_error_work);
 713         journal_t *journal = sbi->s_journal;
 714         handle_t *handle;
 715
 716         /*
 717          * If the journal is still running, we have to write out superblock
 718          * through the journal to avoid collisions of other journalled sb
 719          * updates.
 720          *
 721          * We use directly jbd2 functions here to avoid recursing back into
 722          * ext4 error handling code during handling of previous errors.
 723          */
 724         if (!sb_rdonly(sbi->s_sb) && journal) {
 725                 struct buffer_head *sbh = sbi->s_sbh;
 726                 handle = jbd2_journal_start(journal, 1);
 727                 if (IS_ERR(handle))
 728                         goto write_directly;
 729                 if (jbd2_journal_get_write_access(handle, sbh)) {
 730                         jbd2_journal_stop(handle);
 731                         goto write_directly;
 732                 }
 733                 ext4_update_super(sbi->s_sb);
 734                 if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
 735                         ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
 736                                  "superblock detected");
 737                         clear_buffer_write_io_error(sbh);
 738                         set_buffer_uptodate(sbh);
 739                 }
 740
 741                 if (jbd2_journal_dirty_metadata(handle, sbh)) {
 742                         jbd2_journal_stop(handle);
 743                         goto write_directly;
 744                 }
 745                 jbd2_journal_stop(handle);
 746                 ext4_notify_error_sysfs(sbi);
 747                 return;
 748         }
 749 write_directly:
 750         /*
 751          * Write through journal failed. Write sb directly to get error info
 752          * out and hope for the best.
 753          */
 754         ext4_commit_super(sbi->s_sb);
 755         ext4_notify_error_sysfs(sbi);
 756 }
 757
 758 #define ext4_error_ratelimit(sb)                                        \
 759                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 760                              "EXT4-fs error")
 761
 762 void __ext4_error(struct super_block *sb, const char *function,
 763                   unsigned int line, bool force_ro, int error, __u64 block,
 764                   const char *fmt, ...)
 765 {
 766         struct va_format vaf;
 767         va_list args;
 768
 769         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 770                 return;
 771
 772         trace_ext4_error(sb, function, line);
 773         if (ext4_error_ratelimit(sb)) {
 774                 va_start(args, fmt);
 775                 vaf.fmt = fmt;
 776                 vaf.va = &args;
 777                 printk(KERN_CRIT
 778                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 779                        sb->s_id, function, line, current->comm, &vaf);
 780                 va_end(args);
 781         }
 782         fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
 783
 784         ext4_handle_error(sb, force_ro, error, 0, block, function, line);
 785 }
 786
 787 void __ext4_error_inode(struct inode *inode, const char *function,
 788                         unsigned int line, ext4_fsblk_t block, int error,
 789                         const char *fmt, ...)
 790 {
 791         va_list args;
 792         struct va_format vaf;
 793
 794         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 795                 return;
 796
 797         trace_ext4_error(inode->i_sb, function, line);
 798         if (ext4_error_ratelimit(inode->i_sb)) {
 799                 va_start(args, fmt);
 800                 vaf.fmt = fmt;
 801                 vaf.va = &args;
 802                 if (block)
 803                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 804                                "inode #%lu: block %llu: comm %s: %pV\n",
 805                                inode->i_sb->s_id, function, line, inode->i_ino,
 806                                block, current->comm, &vaf);
 807                 else
 808                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 809                                "inode #%lu: comm %s: %pV\n",
 810                                inode->i_sb->s_id, function, line, inode->i_ino,
 811                                current->comm, &vaf);
 812                 va_end(args);
 813         }
 814         fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
 815
 816         ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
 817                           function, line);
 818 }
 819
 820 void __ext4_error_file(struct file *file, const char *function,
 821                        unsigned int line, ext4_fsblk_t block,
 822                        const char *fmt, ...)
 823 {
 824         va_list args;
 825         struct va_format vaf;
 826         struct inode *inode = file_inode(file);
 827         char pathname[80], *path;
 828
 829         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 830                 return;
 831
 832         trace_ext4_error(inode->i_sb, function, line);
 833         if (ext4_error_ratelimit(inode->i_sb)) {
 834                 path = file_path(file, pathname, sizeof(pathname));
 835                 if (IS_ERR(path))
 836                         path = "(unknown)";
 837                 va_start(args, fmt);
 838                 vaf.fmt = fmt;
 839                 vaf.va = &args;
 840                 if (block)
 841                         printk(KERN_CRIT
 842                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 843                                "block %llu: comm %s: path %s: %pV\n",
 844                                inode->i_sb->s_id, function, line, inode->i_ino,
 845                                block, current->comm, path, &vaf);
 846                 else
 847                         printk(KERN_CRIT
 848                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 849                                "comm %s: path %s: %pV\n",
 850                                inode->i_sb->s_id, function, line, inode->i_ino,
 851                                current->comm, path, &vaf);
 852                 va_end(args);
 853         }
 854         fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
 855
 856         ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
 857                           function, line);
 858 }
 859
 860 const char *ext4_decode_error(struct super_block *sb, int errno,
 861                               char nbuf[16])
 862 {
 863         char *errstr = NULL;
 864
 865         switch (errno) {
 866         case -EFSCORRUPTED:
 867                 errstr = "Corrupt filesystem";
 868                 break;
 869         case -EFSBADCRC:
 870                 errstr = "Filesystem failed CRC";
 871                 break;
 872         case -EIO:
 873                 errstr = "IO failure";
 874                 break;
 875         case -ENOMEM:
 876                 errstr = "Out of memory";
 877                 break;
 878         case -EROFS:
 879                 if (!sb || (EXT4_SB(sb)->s_journal &&
 880                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 881                         errstr = "Journal has aborted";
 882                 else
 883                         errstr = "Readonly filesystem";
 884                 break;
 885         default:
 886                 /* If the caller passed in an extra buffer for unknown
 887                  * errors, textualise them now.  Else we just return
 888                  * NULL. */
 889                 if (nbuf) {
 890                         /* Check for truncated error codes... */
 891                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 892                                 errstr = nbuf;
 893                 }
 894                 break;
 895         }
 896
 897         return errstr;
 898 }
 899
 900 /* __ext4_std_error decodes expected errors from journaling functions
 901  * automatically and invokes the appropriate error response.  */
 902
 903 void __ext4_std_error(struct super_block *sb, const char *function,
 904                       unsigned int line, int errno)
 905 {
 906         char nbuf[16];
 907         const char *errstr;
 908
 909         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 910                 return;
 911
 912         /* Special case: if the error is EROFS, and we're not already
 913          * inside a transaction, then there's really no point in logging
 914          * an error. */
 915         if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
 916                 return;
 917
 918         if (ext4_error_ratelimit(sb)) {
 919                 errstr = ext4_decode_error(sb, errno, nbuf);
 920                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 921                        sb->s_id, function, line, errstr);
 922         }
 923         fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
 924
 925         ext4_handle_error(sb, false, -errno, 0, 0, function, line);
 926 }
 927
 928 void __ext4_msg(struct super_block *sb,
 929                 const char *prefix, const char *fmt, ...)
 930 {
 931         struct va_format vaf;
 932         va_list args;
 933
 934         if (sb) {
 935                 atomic_inc(&EXT4_SB(sb)->s_msg_count);
 936                 if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
 937                                   "EXT4-fs"))
 938                         return;
 939         }
 940
 941         va_start(args, fmt);
 942         vaf.fmt = fmt;
 943         vaf.va = &args;
 944         if (sb)
 945                 printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 946         else
 947                 printk("%sEXT4-fs: %pV\n", prefix, &vaf);
 948         va_end(args);
 949 }
 950
 951 static int ext4_warning_ratelimit(struct super_block *sb)
 952 {
 953         atomic_inc(&EXT4_SB(sb)->s_warning_count);
 954         return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
 955                             "EXT4-fs warning");
 956 }
 957
 958 void __ext4_warning(struct super_block *sb, const char *function,
 959                     unsigned int line, const char *fmt, ...)
 960 {
 961         struct va_format vaf;
 962         va_list args;
 963
 964         if (!ext4_warning_ratelimit(sb))
 965                 return;
 966
 967         va_start(args, fmt);
 968         vaf.fmt = fmt;
 969         vaf.va = &args;
 970         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 971                sb->s_id, function, line, &vaf);
 972         va_end(args);
 973 }
 974
 975 void __ext4_warning_inode(const struct inode *inode, const char *function,
 976                           unsigned int line, const char *fmt, ...)
 977 {
 978         struct va_format vaf;
 979         va_list args;
 980
 981         if (!ext4_warning_ratelimit(inode->i_sb))
 982                 return;
 983
 984         va_start(args, fmt);
 985         vaf.fmt = fmt;
 986         vaf.va = &args;
 987         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 988                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 989                function, line, inode->i_ino, current->comm, &vaf);
 990         va_end(args);
 991 }
 992
 993 void __ext4_grp_locked_error(const char *function, unsigned int line,
 994                              struct super_block *sb, ext4_group_t grp,
 995                              unsigned long ino, ext4_fsblk_t block,
 996                              const char *fmt, ...)
 997 __releases(bitlock)
 998 __acquires(bitlock)
 999 {
1000         struct va_format vaf;
1001         va_list args;
1002
1003         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
1004                 return;
1005
1006         trace_ext4_error(sb, function, line);
1007         if (ext4_error_ratelimit(sb)) {
1008                 va_start(args, fmt);
1009                 vaf.fmt = fmt;
1010                 vaf.va = &args;
1011                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1012                        sb->s_id, function, line, grp);
1013                 if (ino)
1014                         printk(KERN_CONT "inode %lu: ", ino);
1015                 if (block)
1016                         printk(KERN_CONT "block %llu:",
1017                                (unsigned long long) block);
1018                 printk(KERN_CONT "%pV\n", &vaf);
1019                 va_end(args);
1020         }
1021
1022         if (test_opt(sb, ERRORS_CONT)) {
1023                 if (test_opt(sb, WARN_ON_ERROR))
1024                         WARN_ON_ONCE(1);
1025                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1026                 if (!bdev_read_only(sb->s_bdev)) {
1027                         save_error_info(sb, EFSCORRUPTED, ino, block, function,
1028                                         line);
1029                         schedule_work(&EXT4_SB(sb)->s_error_work);
1030                 }
1031                 return;
1032         }
1033         ext4_unlock_group(sb, grp);
1034         ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1035         /*
1036          * We only get here in the ERRORS_RO case; relocking the group
1037          * may be dangerous, but nothing bad will happen since the
1038          * filesystem will have already been marked read/only and the
1039          * journal has been aborted.  We return 1 as a hint to callers
1040          * who might what to use the return value from
1041          * ext4_grp_locked_error() to distinguish between the
1042          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1043          * aggressively from the ext4 function in question, with a
1044          * more appropriate error code.
1045          */
1046         ext4_lock_group(sb, grp);
1047         return;
1048 }
1049
1050 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1051                                      ext4_group_t group,
1052                                      unsigned int flags)
1053 {
1054         struct ext4_sb_info *sbi = EXT4_SB(sb);
1055         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1056         struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1057         int ret;
1058
1059         if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1060                 ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1061                                             &grp->bb_state);
1062                 if (!ret)
1063                         percpu_counter_sub(&sbi->s_freeclusters_counter,
1064                                            grp->bb_free);
1065         }
1066
1067         if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1068                 ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1069                                             &grp->bb_state);
1070                 if (!ret && gdp) {
1071                         int count;
1072
1073                         count = ext4_free_inodes_count(sb, gdp);
1074                         percpu_counter_sub(&sbi->s_freeinodes_counter,
1075                                            count);
1076                 }
1077         }
1078 }
1079
1080 void ext4_update_dynamic_rev(struct super_block *sb)
1081 {
1082         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1083
1084         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1085                 return;
1086
1087         ext4_warning(sb,
1088                      "updating to rev %d because of new feature flag, "
1089                      "running e2fsck is recommended",
1090                      EXT4_DYNAMIC_REV);
1091
1092         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1093         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1094         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1095         /* leave es->s_feature_*compat flags alone */
1096         /* es->s_uuid will be set by e2fsck if empty */
1097
1098         /*
1099          * The rest of the superblock fields should be zero, and if not it
1100          * means they are likely already in use, so leave them alone.  We
1101          * can leave it up to e2fsck to clean up any inconsistencies there.
1102          */
1103 }
1104
1105 /*
1106  * Open the external journal device
1107  */
1108 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1109 {
1110         struct block_device *bdev;
1111
1112         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1113         if (IS_ERR(bdev))
1114                 goto fail;
1115         return bdev;
1116
1117 fail:
1118         ext4_msg(sb, KERN_ERR,
1119                  "failed to open journal device unknown-block(%u,%u) %ld",
1120                  MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1121         return NULL;
1122 }
1123
1124 /*
1125  * Release the journal device
1126  */
1127 static void ext4_blkdev_put(struct block_device *bdev)
1128 {
1129         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1130 }
1131
1132 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1133 {
1134         struct block_device *bdev;
1135         bdev = sbi->s_journal_bdev;
1136         if (bdev) {
1137                 ext4_blkdev_put(bdev);
1138                 sbi->s_journal_bdev = NULL;
1139         }
1140 }
1141
1142 static inline struct inode *orphan_list_entry(struct list_head *l)
1143 {
1144         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1145 }
1146
1147 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1148 {
1149         struct list_head *l;
1150
1151         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1152                  le32_to_cpu(sbi->s_es->s_last_orphan));
1153
1154         printk(KERN_ERR "sb_info orphan list:\n");
1155         list_for_each(l, &sbi->s_orphan) {
1156                 struct inode *inode = orphan_list_entry(l);
1157                 printk(KERN_ERR "  "
1158                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1159                        inode->i_sb->s_id, inode->i_ino, inode,
1160                        inode->i_mode, inode->i_nlink,
1161                        NEXT_ORPHAN(inode));
1162         }
1163 }
1164
1165 #ifdef CONFIG_QUOTA
1166 static int ext4_quota_off(struct super_block *sb, int type);
1167
1168 static inline void ext4_quota_off_umount(struct super_block *sb)
1169 {
1170         int type;
1171
1172         /* Use our quota_off function to clear inode flags etc. */
1173         for (type = 0; type < EXT4_MAXQUOTAS; type++)
1174                 ext4_quota_off(sb, type);
1175 }
1176
1177 /*
1178  * This is a helper function which is used in the mount/remount
1179  * codepaths (which holds s_umount) to fetch the quota file name.
1180  */
1181 static inline char *get_qf_name(struct super_block *sb,
1182                                 struct ext4_sb_info *sbi,
1183                                 int type)
1184 {
1185         return rcu_dereference_protected(sbi->s_qf_names[type],
1186                                          lockdep_is_held(&sb->s_umount));
1187 }
1188 #else
1189 static inline void ext4_quota_off_umount(struct super_block *sb)
1190 {
1191 }
1192 #endif
1193
1194 static void ext4_put_super(struct super_block *sb)
1195 {
1196         struct ext4_sb_info *sbi = EXT4_SB(sb);
1197         struct ext4_super_block *es = sbi->s_es;
1198         struct buffer_head **group_desc;
1199         struct flex_groups **flex_groups;
1200         int aborted = 0;
1201         int i, err;
1202
1203         ext4_unregister_li_request(sb);
1204         ext4_quota_off_umount(sb);
1205
1206         flush_work(&sbi->s_error_work);
1207         destroy_workqueue(sbi->rsv_conversion_wq);
1208         ext4_release_orphan_info(sb);
1209
1210         /*
1211          * Unregister sysfs before destroying jbd2 journal.
1212          * Since we could still access attr_journal_task attribute via sysfs
1213          * path which could have sbi->s_journal->j_task as NULL
1214          */
1215         ext4_unregister_sysfs(sb);
1216
1217         if (sbi->s_journal) {
1218                 aborted = is_journal_aborted(sbi->s_journal);
1219                 err = jbd2_journal_destroy(sbi->s_journal);
1220                 sbi->s_journal = NULL;
1221                 if ((err < 0) && !aborted) {
1222                         ext4_abort(sb, -err, "Couldn't clean up the journal");
1223                 }
1224         }
1225
1226         ext4_es_unregister_shrinker(sbi);
1227         del_timer_sync(&sbi->s_err_report);
1228         ext4_release_system_zone(sb);
1229         ext4_mb_release(sb);
1230         ext4_ext_release(sb);
1231
1232         if (!sb_rdonly(sb) && !aborted) {
1233                 ext4_clear_feature_journal_needs_recovery(sb);
1234                 ext4_clear_feature_orphan_present(sb);
1235                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1236         }
1237         if (!sb_rdonly(sb))
1238                 ext4_commit_super(sb);
1239
1240         rcu_read_lock();
1241         group_desc = rcu_dereference(sbi->s_group_desc);
1242         for (i = 0; i < sbi->s_gdb_count; i++)
1243                 brelse(group_desc[i]);
1244         kvfree(group_desc);
1245         flex_groups = rcu_dereference(sbi->s_flex_groups);
1246         if (flex_groups) {
1247                 for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1248                         kvfree(flex_groups[i]);
1249                 kvfree(flex_groups);
1250         }
1251         rcu_read_unlock();
1252         percpu_counter_destroy(&sbi->s_freeclusters_counter);
1253         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1254         percpu_counter_destroy(&sbi->s_dirs_counter);
1255         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1256         percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1257         percpu_free_rwsem(&sbi->s_writepages_rwsem);
1258 #ifdef CONFIG_QUOTA
1259         for (i = 0; i < EXT4_MAXQUOTAS; i++)
1260                 kfree(get_qf_name(sb, sbi, i));
1261 #endif
1262
1263         /* Debugging code just in case the in-memory inode orphan list
1264          * isn't empty.  The on-disk one can be non-empty if we've
1265          * detected an error and taken the fs readonly, but the
1266          * in-memory list had better be clean by this point. */
1267         if (!list_empty(&sbi->s_orphan))
1268                 dump_orphan_list(sb, sbi);
1269         ASSERT(list_empty(&sbi->s_orphan));
1270
1271         sync_blockdev(sb->s_bdev);
1272         invalidate_bdev(sb->s_bdev);
1273         if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1274                 /*
1275                  * Invalidate the journal device's buffers.  We don't want them
1276                  * floating about in memory - the physical journal device may
1277                  * hotswapped, and it breaks the `ro-after' testing code.
1278                  */
1279                 sync_blockdev(sbi->s_journal_bdev);
1280                 invalidate_bdev(sbi->s_journal_bdev);
1281                 ext4_blkdev_remove(sbi);
1282         }
1283
1284         ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1285         sbi->s_ea_inode_cache = NULL;
1286
1287         ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1288         sbi->s_ea_block_cache = NULL;
1289
1290         ext4_stop_mmpd(sbi);
1291
1292         brelse(sbi->s_sbh);
1293         sb->s_fs_info = NULL;
1294         /*
1295          * Now that we are completely done shutting down the
1296          * superblock, we need to actually destroy the kobject.
1297          */
1298         kobject_put(&sbi->s_kobj);
1299         wait_for_completion(&sbi->s_kobj_unregister);
1300         if (sbi->s_chksum_driver)
1301                 crypto_free_shash(sbi->s_chksum_driver);
1302         kfree(sbi->s_blockgroup_lock);
1303         fs_put_dax(sbi->s_daxdev);
1304         fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1305 #ifdef CONFIG_UNICODE
1306         utf8_unload(sb->s_encoding);
1307 #endif
1308         kfree(sbi);
1309 }
1310
1311 static struct kmem_cache *ext4_inode_cachep;
1312
1313 /*
1314  * Called inside transaction, so use GFP_NOFS
1315  */
1316 static struct inode *ext4_alloc_inode(struct super_block *sb)
1317 {
1318         struct ext4_inode_info *ei;
1319
1320         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1321         if (!ei)
1322                 return NULL;
1323
1324         inode_set_iversion(&ei->vfs_inode, 1);
1325         spin_lock_init(&ei->i_raw_lock);
1326         INIT_LIST_HEAD(&ei->i_prealloc_list);
1327         atomic_set(&ei->i_prealloc_active, 0);
1328         spin_lock_init(&ei->i_prealloc_lock);
1329         ext4_es_init_tree(&ei->i_es_tree);
1330         rwlock_init(&ei->i_es_lock);
1331         INIT_LIST_HEAD(&ei->i_es_list);
1332         ei->i_es_all_nr = 0;
1333         ei->i_es_shk_nr = 0;
1334         ei->i_es_shrink_lblk = 0;
1335         ei->i_reserved_data_blocks = 0;
1336         spin_lock_init(&(ei->i_block_reservation_lock));
1337         ext4_init_pending_tree(&ei->i_pending_tree);
1338 #ifdef CONFIG_QUOTA
1339         ei->i_reserved_quota = 0;
1340         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1341 #endif
1342         ei->jinode = NULL;
1343         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1344         spin_lock_init(&ei->i_completed_io_lock);
1345         ei->i_sync_tid = 0;
1346         ei->i_datasync_tid = 0;
1347         atomic_set(&ei->i_unwritten, 0);
1348         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1349         ext4_fc_init_inode(&ei->vfs_inode);
1350         mutex_init(&ei->i_fc_lock);
1351         return &ei->vfs_inode;
1352 }
1353
1354 static int ext4_drop_inode(struct inode *inode)
1355 {
1356         int drop = generic_drop_inode(inode);
1357
1358         if (!drop)
1359                 drop = fscrypt_drop_inode(inode);
1360
1361         trace_ext4_drop_inode(inode, drop);
1362         return drop;
1363 }
1364
1365 static void ext4_free_in_core_inode(struct inode *inode)
1366 {
1367         fscrypt_free_inode(inode);
1368         if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1369                 pr_warn("%s: inode %ld still in fc list",
1370                         __func__, inode->i_ino);
1371         }
1372         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1373 }
1374
1375 static void ext4_destroy_inode(struct inode *inode)
1376 {
1377         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1378                 ext4_msg(inode->i_sb, KERN_ERR,
1379                          "Inode %lu (%p): orphan list check failed!",
1380                          inode->i_ino, EXT4_I(inode));
1381                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1382                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
1383                                 true);
1384                 dump_stack();
1385         }
1386
1387         if (EXT4_I(inode)->i_reserved_data_blocks)
1388                 ext4_msg(inode->i_sb, KERN_ERR,
1389                          "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1390                          inode->i_ino, EXT4_I(inode),
1391                          EXT4_I(inode)->i_reserved_data_blocks);
1392 }
1393
1394 static void init_once(void *foo)
1395 {
1396         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1397
1398         INIT_LIST_HEAD(&ei->i_orphan);
1399         init_rwsem(&ei->xattr_sem);
1400         init_rwsem(&ei->i_data_sem);
1401         inode_init_once(&ei->vfs_inode);
1402         ext4_fc_init_inode(&ei->vfs_inode);
1403 }
1404
1405 static int __init init_inodecache(void)
1406 {
1407         ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1408                                 sizeof(struct ext4_inode_info), 0,
1409                                 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1410                                         SLAB_ACCOUNT),
1411                                 offsetof(struct ext4_inode_info, i_data),
1412                                 sizeof_field(struct ext4_inode_info, i_data),
1413                                 init_once);
1414         if (ext4_inode_cachep == NULL)
1415                 return -ENOMEM;
1416         return 0;
1417 }
1418
1419 static void destroy_inodecache(void)
1420 {
1421         /*
1422          * Make sure all delayed rcu free inodes are flushed before we
1423          * destroy cache.
1424          */
1425         rcu_barrier();
1426         kmem_cache_destroy(ext4_inode_cachep);
1427 }
1428
1429 void ext4_clear_inode(struct inode *inode)
1430 {
1431         ext4_fc_del(inode);
1432         invalidate_inode_buffers(inode);
1433         clear_inode(inode);
1434         ext4_discard_preallocations(inode, 0);
1435         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1436         dquot_drop(inode);
1437         if (EXT4_I(inode)->jinode) {
1438                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1439                                                EXT4_I(inode)->jinode);
1440                 jbd2_free_inode(EXT4_I(inode)->jinode);
1441                 EXT4_I(inode)->jinode = NULL;
1442         }
1443         fscrypt_put_encryption_info(inode);
1444         fsverity_cleanup_inode(inode);
1445 }
1446
1447 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1448                                         u64 ino, u32 generation)
1449 {
1450         struct inode *inode;
1451
1452         /*
1453          * Currently we don't know the generation for parent directory, so
1454          * a generation of 0 means "accept any"
1455          */
1456         inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1457         if (IS_ERR(inode))
1458                 return ERR_CAST(inode);
1459         if (generation && inode->i_generation != generation) {
1460                 iput(inode);
1461                 return ERR_PTR(-ESTALE);
1462         }
1463
1464         return inode;
1465 }
1466
1467 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1468                                         int fh_len, int fh_type)
1469 {
1470         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1471                                     ext4_nfs_get_inode);
1472 }
1473
1474 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1475                                         int fh_len, int fh_type)
1476 {
1477         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1478                                     ext4_nfs_get_inode);
1479 }
1480
1481 static int ext4_nfs_commit_metadata(struct inode *inode)
1482 {
1483         struct writeback_control wbc = {
1484                 .sync_mode = WB_SYNC_ALL
1485         };
1486
1487         trace_ext4_nfs_commit_metadata(inode);
1488         return ext4_write_inode(inode, &wbc);
1489 }
1490
1491 #ifdef CONFIG_FS_ENCRYPTION
1492 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1493 {
1494         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1495                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1496 }
1497
1498 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1499                                                         void *fs_data)
1500 {
1501         handle_t *handle = fs_data;
1502         int res, res2, credits, retries = 0;
1503
1504         /*
1505          * Encrypting the root directory is not allowed because e2fsck expects
1506          * lost+found to exist and be unencrypted, and encrypting the root
1507          * directory would imply encrypting the lost+found directory as well as
1508          * the filename "lost+found" itself.
1509          */
1510         if (inode->i_ino == EXT4_ROOT_INO)
1511                 return -EPERM;
1512
1513         if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1514                 return -EINVAL;
1515
1516         if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
1517                 return -EOPNOTSUPP;
1518
1519         res = ext4_convert_inline_data(inode);
1520         if (res)
1521                 return res;
1522
1523         /*
1524          * If a journal handle was specified, then the encryption context is
1525          * being set on a new inode via inheritance and is part of a larger
1526          * transaction to create the inode.  Otherwise the encryption context is
1527          * being set on an existing inode in its own transaction.  Only in the
1528          * latter case should the "retry on ENOSPC" logic be used.
1529          */
1530
1531         if (handle) {
1532                 res = ext4_xattr_set_handle(handle, inode,
1533                                             EXT4_XATTR_INDEX_ENCRYPTION,
1534                                             EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1535                                             ctx, len, 0);
1536                 if (!res) {
1537                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1538                         ext4_clear_inode_state(inode,
1539                                         EXT4_STATE_MAY_INLINE_DATA);
1540                         /*
1541                          * Update inode->i_flags - S_ENCRYPTED will be enabled,
1542                          * S_DAX may be disabled
1543                          */
1544                         ext4_set_inode_flags(inode, false);
1545                 }
1546                 return res;
1547         }
1548
1549         res = dquot_initialize(inode);
1550         if (res)
1551                 return res;
1552 retry:
1553         res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1554                                      &credits);
1555         if (res)
1556                 return res;
1557
1558         handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1559         if (IS_ERR(handle))
1560                 return PTR_ERR(handle);
1561
1562         res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1563                                     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1564                                     ctx, len, 0);
1565         if (!res) {
1566                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1567                 /*
1568                  * Update inode->i_flags - S_ENCRYPTED will be enabled,
1569                  * S_DAX may be disabled
1570                  */
1571                 ext4_set_inode_flags(inode, false);
1572                 res = ext4_mark_inode_dirty(handle, inode);
1573                 if (res)
1574                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1575         }
1576         res2 = ext4_journal_stop(handle);
1577
1578         if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1579                 goto retry;
1580         if (!res)
1581                 res = res2;
1582         return res;
1583 }
1584
1585 static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
1586 {
1587         return EXT4_SB(sb)->s_dummy_enc_policy.policy;
1588 }
1589
1590 static bool ext4_has_stable_inodes(struct super_block *sb)
1591 {
1592         return ext4_has_feature_stable_inodes(sb);
1593 }
1594
1595 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1596                                        int *ino_bits_ret, int *lblk_bits_ret)
1597 {
1598         *ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1599         *lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1600 }
1601
1602 static const struct fscrypt_operations ext4_cryptops = {
1603         .key_prefix             = "ext4:",
1604         .get_context            = ext4_get_context,
1605         .set_context            = ext4_set_context,
1606         .get_dummy_policy       = ext4_get_dummy_policy,
1607         .empty_dir              = ext4_empty_dir,
1608         .has_stable_inodes      = ext4_has_stable_inodes,
1609         .get_ino_and_lblk_bits  = ext4_get_ino_and_lblk_bits,
1610 };
1611 #endif
1612
1613 #ifdef CONFIG_QUOTA
1614 static const char * const quotatypes[] = INITQFNAMES;
1615 #define QTYPE2NAME(t) (quotatypes[t])
1616
1617 static int ext4_write_dquot(struct dquot *dquot);
1618 static int ext4_acquire_dquot(struct dquot *dquot);
1619 static int ext4_release_dquot(struct dquot *dquot);
1620 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1621 static int ext4_write_info(struct super_block *sb, int type);
1622 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1623                          const struct path *path);
1624 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1625                                size_t len, loff_t off);
1626 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1627                                 const char *data, size_t len, loff_t off);
1628 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1629                              unsigned int flags);
1630
1631 static struct dquot **ext4_get_dquots(struct inode *inode)
1632 {
1633         return EXT4_I(inode)->i_dquot;
1634 }
1635
1636 static const struct dquot_operations ext4_quota_operations = {
1637         .get_reserved_space     = ext4_get_reserved_space,
1638         .write_dquot            = ext4_write_dquot,
1639         .acquire_dquot          = ext4_acquire_dquot,
1640         .release_dquot          = ext4_release_dquot,
1641         .mark_dirty             = ext4_mark_dquot_dirty,
1642         .write_info             = ext4_write_info,
1643         .alloc_dquot            = dquot_alloc,
1644         .destroy_dquot          = dquot_destroy,
1645         .get_projid             = ext4_get_projid,
1646         .get_inode_usage        = ext4_get_inode_usage,
1647         .get_next_id            = dquot_get_next_id,
1648 };
1649
1650 static const struct quotactl_ops ext4_qctl_operations = {
1651         .quota_on       = ext4_quota_on,
1652         .quota_off      = ext4_quota_off,
1653         .quota_sync     = dquot_quota_sync,
1654         .get_state      = dquot_get_state,
1655         .set_info       = dquot_set_dqinfo,
1656         .get_dqblk      = dquot_get_dqblk,
1657         .set_dqblk      = dquot_set_dqblk,
1658         .get_nextdqblk  = dquot_get_next_dqblk,
1659 };
1660 #endif
1661
1662 static const struct super_operations ext4_sops = {
1663         .alloc_inode    = ext4_alloc_inode,
1664         .free_inode     = ext4_free_in_core_inode,
1665         .destroy_inode  = ext4_destroy_inode,
1666         .write_inode    = ext4_write_inode,
1667         .dirty_inode    = ext4_dirty_inode,
1668         .drop_inode     = ext4_drop_inode,
1669         .evict_inode    = ext4_evict_inode,
1670         .put_super      = ext4_put_super,
1671         .sync_fs        = ext4_sync_fs,
1672         .freeze_fs      = ext4_freeze,
1673         .unfreeze_fs    = ext4_unfreeze,
1674         .statfs         = ext4_statfs,
1675         .show_options   = ext4_show_options,
1676 #ifdef CONFIG_QUOTA
1677         .quota_read     = ext4_quota_read,
1678         .quota_write    = ext4_quota_write,
1679         .get_dquots     = ext4_get_dquots,
1680 #endif
1681 };
1682
1683 static const struct export_operations ext4_export_ops = {
1684         .fh_to_dentry = ext4_fh_to_dentry,
1685         .fh_to_parent = ext4_fh_to_parent,
1686         .get_parent = ext4_get_parent,
1687         .commit_metadata = ext4_nfs_commit_metadata,
1688 };
1689
1690 enum {
1691         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1692         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1693         Opt_nouid32, Opt_debug, Opt_removed,
1694         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1695         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1696         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1697         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1698         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1699         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1700         Opt_inlinecrypt,
1701         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1702         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1703         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1704         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1705         Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1706         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1707         Opt_nowarn_on_error, Opt_mblk_io_submit,
1708         Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1709         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1710         Opt_inode_readahead_blks, Opt_journal_ioprio,
1711         Opt_dioread_nolock, Opt_dioread_lock,
1712         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1713         Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1714         Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1715         Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1716 #ifdef CONFIG_EXT4_DEBUG
1717         Opt_fc_debug_max_replay, Opt_fc_debug_force
1718 #endif
1719 };
1720
1721 static const struct constant_table ext4_param_errors[] = {
1722         {"continue",    Opt_err_cont},
1723         {"panic",       Opt_err_panic},
1724         {"remount-ro",  Opt_err_ro},
1725         {}
1726 };
1727
1728 static const struct constant_table ext4_param_data[] = {
1729         {"journal",     Opt_data_journal},
1730         {"ordered",     Opt_data_ordered},
1731         {"writeback",   Opt_data_writeback},
1732         {}
1733 };
1734
1735 static const struct constant_table ext4_param_data_err[] = {
1736         {"abort",       Opt_data_err_abort},
1737         {"ignore",      Opt_data_err_ignore},
1738         {}
1739 };
1740
1741 static const struct constant_table ext4_param_jqfmt[] = {
1742         {"vfsold",      Opt_jqfmt_vfsold},
1743         {"vfsv0",       Opt_jqfmt_vfsv0},
1744         {"vfsv1",       Opt_jqfmt_vfsv1},
1745         {}
1746 };
1747
1748 static const struct constant_table ext4_param_dax[] = {
1749         {"always",      Opt_dax_always},
1750         {"inode",       Opt_dax_inode},
1751         {"never",       Opt_dax_never},
1752         {}
1753 };
1754
1755 /* String parameter that allows empty argument */
1756 #define fsparam_string_empty(NAME, OPT) \
1757         __fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1758
1759 /*
1760  * Mount option specification
1761  * We don't use fsparam_flag_no because of the way we set the
1762  * options and the way we show them in _ext4_show_options(). To
1763  * keep the changes to a minimum, let's keep the negative options
1764  * separate for now.
1765  */
1766 static const struct fs_parameter_spec ext4_param_specs[] = {
1767         fsparam_flag    ("bsddf",               Opt_bsd_df),
1768         fsparam_flag    ("minixdf",             Opt_minix_df),
1769         fsparam_flag    ("grpid",               Opt_grpid),
1770         fsparam_flag    ("bsdgroups",           Opt_grpid),
1771         fsparam_flag    ("nogrpid",             Opt_nogrpid),
1772         fsparam_flag    ("sysvgroups",          Opt_nogrpid),
1773         fsparam_u32     ("resgid",              Opt_resgid),
1774         fsparam_u32     ("resuid",              Opt_resuid),
1775         fsparam_u32     ("sb",                  Opt_sb),
1776         fsparam_enum    ("errors",              Opt_errors, ext4_param_errors),
1777         fsparam_flag    ("nouid32",             Opt_nouid32),
1778         fsparam_flag    ("debug",               Opt_debug),
1779         fsparam_flag    ("oldalloc",            Opt_removed),
1780         fsparam_flag    ("orlov",               Opt_removed),
1781         fsparam_flag    ("user_xattr",          Opt_user_xattr),
1782         fsparam_flag    ("nouser_xattr",        Opt_nouser_xattr),
1783         fsparam_flag    ("acl",                 Opt_acl),
1784         fsparam_flag    ("noacl",               Opt_noacl),
1785         fsparam_flag    ("norecovery",          Opt_noload),
1786         fsparam_flag    ("noload",              Opt_noload),
1787         fsparam_flag    ("bh",                  Opt_removed),
1788         fsparam_flag    ("nobh",                Opt_removed),
1789         fsparam_u32     ("commit",              Opt_commit),
1790         fsparam_u32     ("min_batch_time",      Opt_min_batch_time),
1791         fsparam_u32     ("max_batch_time",      Opt_max_batch_time),
1792         fsparam_u32     ("journal_dev",         Opt_journal_dev),
1793         fsparam_bdev    ("journal_path",        Opt_journal_path),
1794         fsparam_flag    ("journal_checksum",    Opt_journal_checksum),
1795         fsparam_flag    ("nojournal_checksum",  Opt_nojournal_checksum),
1796         fsparam_flag    ("journal_async_commit",Opt_journal_async_commit),
1797         fsparam_flag    ("abort",               Opt_abort),
1798         fsparam_enum    ("data",                Opt_data, ext4_param_data),
1799         fsparam_enum    ("data_err",            Opt_data_err,
1800                                                 ext4_param_data_err),
1801         fsparam_string_empty
1802                         ("usrjquota",           Opt_usrjquota),
1803         fsparam_string_empty
1804                         ("grpjquota",           Opt_grpjquota),
1805         fsparam_enum    ("jqfmt",               Opt_jqfmt, ext4_param_jqfmt),
1806         fsparam_flag    ("grpquota",            Opt_grpquota),
1807         fsparam_flag    ("quota",               Opt_quota),
1808         fsparam_flag    ("noquota",             Opt_noquota),
1809         fsparam_flag    ("usrquota",            Opt_usrquota),
1810         fsparam_flag    ("prjquota",            Opt_prjquota),
1811         fsparam_flag    ("barrier",             Opt_barrier),
1812         fsparam_u32     ("barrier",             Opt_barrier),
1813         fsparam_flag    ("nobarrier",           Opt_nobarrier),
1814         fsparam_flag    ("i_version",           Opt_i_version),
1815         fsparam_flag    ("dax",                 Opt_dax),
1816         fsparam_enum    ("dax",                 Opt_dax_type, ext4_param_dax),
1817         fsparam_u32     ("stripe",              Opt_stripe),
1818         fsparam_flag    ("delalloc",            Opt_delalloc),
1819         fsparam_flag    ("nodelalloc",          Opt_nodelalloc),
1820         fsparam_flag    ("warn_on_error",       Opt_warn_on_error),
1821         fsparam_flag    ("nowarn_on_error",     Opt_nowarn_on_error),
1822         fsparam_flag    ("lazytime",            Opt_lazytime),
1823         fsparam_flag    ("nolazytime",          Opt_nolazytime),
1824         fsparam_u32     ("debug_want_extra_isize",
1825                                                 Opt_debug_want_extra_isize),
1826         fsparam_flag    ("mblk_io_submit",      Opt_removed),
1827         fsparam_flag    ("nomblk_io_submit",    Opt_removed),
1828         fsparam_flag    ("block_validity",      Opt_block_validity),
1829         fsparam_flag    ("noblock_validity",    Opt_noblock_validity),
1830         fsparam_u32     ("inode_readahead_blks",
1831                                                 Opt_inode_readahead_blks),
1832         fsparam_u32     ("journal_ioprio",      Opt_journal_ioprio),
1833         fsparam_u32     ("auto_da_alloc",       Opt_auto_da_alloc),
1834         fsparam_flag    ("auto_da_alloc",       Opt_auto_da_alloc),
1835         fsparam_flag    ("noauto_da_alloc",     Opt_noauto_da_alloc),
1836         fsparam_flag    ("dioread_nolock",      Opt_dioread_nolock),
1837         fsparam_flag    ("nodioread_nolock",    Opt_dioread_lock),
1838         fsparam_flag    ("dioread_lock",        Opt_dioread_lock),
1839         fsparam_flag    ("discard",             Opt_discard),
1840         fsparam_flag    ("nodiscard",           Opt_nodiscard),
1841         fsparam_u32     ("init_itable",         Opt_init_itable),
1842         fsparam_flag    ("init_itable",         Opt_init_itable),
1843         fsparam_flag    ("noinit_itable",       Opt_noinit_itable),
1844 #ifdef CONFIG_EXT4_DEBUG
1845         fsparam_flag    ("fc_debug_force",      Opt_fc_debug_force),
1846         fsparam_u32     ("fc_debug_max_replay", Opt_fc_debug_max_replay),
1847 #endif
1848         fsparam_u32     ("max_dir_size_kb",     Opt_max_dir_size_kb),
1849         fsparam_flag    ("test_dummy_encryption",
1850                                                 Opt_test_dummy_encryption),
1851         fsparam_string  ("test_dummy_encryption",
1852                                                 Opt_test_dummy_encryption),
1853         fsparam_flag    ("inlinecrypt",         Opt_inlinecrypt),
1854         fsparam_flag    ("nombcache",           Opt_nombcache),
1855         fsparam_flag    ("no_mbcache",          Opt_nombcache), /* for backward compatibility */
1856         fsparam_flag    ("prefetch_block_bitmaps",
1857                                                 Opt_removed),
1858         fsparam_flag    ("no_prefetch_block_bitmaps",
1859                                                 Opt_no_prefetch_block_bitmaps),
1860         fsparam_s32     ("mb_optimize_scan",    Opt_mb_optimize_scan),
1861         fsparam_string  ("check",               Opt_removed),   /* mount option from ext2/3 */
1862         fsparam_flag    ("nocheck",             Opt_removed),   /* mount option from ext2/3 */
1863         fsparam_flag    ("reservation",         Opt_removed),   /* mount option from ext2/3 */
1864         fsparam_flag    ("noreservation",       Opt_removed),   /* mount option from ext2/3 */
1865         fsparam_u32     ("journal",             Opt_removed),   /* mount option from ext2/3 */
1866         {}
1867 };
1868
1869 static const match_table_t tokens = {
1870         {Opt_bsd_df, "bsddf"},
1871         {Opt_minix_df, "minixdf"},
1872         {Opt_grpid, "grpid"},
1873         {Opt_grpid, "bsdgroups"},
1874         {Opt_nogrpid, "nogrpid"},
1875         {Opt_nogrpid, "sysvgroups"},
1876         {Opt_resgid, "resgid=%u"},
1877         {Opt_resuid, "resuid=%u"},
1878         {Opt_sb, "sb=%u"},
1879         {Opt_err_cont, "errors=continue"},
1880         {Opt_err_panic, "errors=panic"},
1881         {Opt_err_ro, "errors=remount-ro"},
1882         {Opt_nouid32, "nouid32"},
1883         {Opt_debug, "debug"},
1884         {Opt_removed, "oldalloc"},
1885         {Opt_removed, "orlov"},
1886         {Opt_user_xattr, "user_xattr"},
1887         {Opt_nouser_xattr, "nouser_xattr"},
1888         {Opt_acl, "acl"},
1889         {Opt_noacl, "noacl"},
1890         {Opt_noload, "norecovery"},
1891         {Opt_noload, "noload"},
1892         {Opt_removed, "nobh"},
1893         {Opt_removed, "bh"},
1894         {Opt_commit, "commit=%u"},
1895         {Opt_min_batch_time, "min_batch_time=%u"},
1896         {Opt_max_batch_time, "max_batch_time=%u"},
1897         {Opt_journal_dev, "journal_dev=%u"},
1898         {Opt_journal_path, "journal_path=%s"},
1899         {Opt_journal_checksum, "journal_checksum"},
1900         {Opt_nojournal_checksum, "nojournal_checksum"},
1901         {Opt_journal_async_commit, "journal_async_commit"},
1902         {Opt_abort, "abort"},
1903         {Opt_data_journal, "data=journal"},
1904         {Opt_data_ordered, "data=ordered"},
1905         {Opt_data_writeback, "data=writeback"},
1906         {Opt_data_err_abort, "data_err=abort"},
1907         {Opt_data_err_ignore, "data_err=ignore"},
1908         {Opt_offusrjquota, "usrjquota="},
1909         {Opt_usrjquota, "usrjquota=%s"},
1910         {Opt_offgrpjquota, "grpjquota="},
1911         {Opt_grpjquota, "grpjquota=%s"},
1912         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1913         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1914         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1915         {Opt_grpquota, "grpquota"},
1916         {Opt_noquota, "noquota"},
1917         {Opt_quota, "quota"},
1918         {Opt_usrquota, "usrquota"},
1919         {Opt_prjquota, "prjquota"},
1920         {Opt_barrier, "barrier=%u"},
1921         {Opt_barrier, "barrier"},
1922         {Opt_nobarrier, "nobarrier"},
1923         {Opt_i_version, "i_version"},
1924         {Opt_dax, "dax"},
1925         {Opt_dax_always, "dax=always"},
1926         {Opt_dax_inode, "dax=inode"},
1927         {Opt_dax_never, "dax=never"},
1928         {Opt_stripe, "stripe=%u"},
1929         {Opt_delalloc, "delalloc"},
1930         {Opt_warn_on_error, "warn_on_error"},
1931         {Opt_nowarn_on_error, "nowarn_on_error"},
1932         {Opt_lazytime, "lazytime"},
1933         {Opt_nolazytime, "nolazytime"},
1934         {Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1935         {Opt_nodelalloc, "nodelalloc"},
1936         {Opt_removed, "mblk_io_submit"},
1937         {Opt_removed, "nomblk_io_submit"},
1938         {Opt_block_validity, "block_validity"},
1939         {Opt_noblock_validity, "noblock_validity"},
1940         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1941         {Opt_journal_ioprio, "journal_ioprio=%u"},
1942         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1943         {Opt_auto_da_alloc, "auto_da_alloc"},
1944         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1945         {Opt_dioread_nolock, "dioread_nolock"},
1946         {Opt_dioread_lock, "nodioread_nolock"},
1947         {Opt_dioread_lock, "dioread_lock"},
1948         {Opt_discard, "discard"},
1949         {Opt_nodiscard, "nodiscard"},
1950         {Opt_init_itable, "init_itable=%u"},
1951         {Opt_init_itable, "init_itable"},
1952         {Opt_noinit_itable, "noinit_itable"},
1953 #ifdef CONFIG_EXT4_DEBUG
1954         {Opt_fc_debug_force, "fc_debug_force"},
1955         {Opt_fc_debug_max_replay, "fc_debug_max_replay=%u"},
1956 #endif
1957         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1958         {Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
1959         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1960         {Opt_inlinecrypt, "inlinecrypt"},
1961         {Opt_nombcache, "nombcache"},
1962         {Opt_nombcache, "no_mbcache"},  /* for backward compatibility */
1963         {Opt_removed, "prefetch_block_bitmaps"},
1964         {Opt_no_prefetch_block_bitmaps, "no_prefetch_block_bitmaps"},
1965         {Opt_mb_optimize_scan, "mb_optimize_scan=%d"},
1966         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1967         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1968         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1969         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1970         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1971         {Opt_err, NULL},
1972 };
1973
1974 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1975 #define DEFAULT_MB_OPTIMIZE_SCAN        (-1)
1976
1977 static const char deprecated_msg[] =
1978         "Mount option \"%s\" will be removed by %s\n"
1979         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1980
1981 #define MOPT_SET        0x0001
1982 #define MOPT_CLEAR      0x0002
1983 #define MOPT_NOSUPPORT  0x0004
1984 #define MOPT_EXPLICIT   0x0008
1985 #define MOPT_CLEAR_ERR  0x0010
1986 #define MOPT_GTE0       0x0020
1987 #ifdef CONFIG_QUOTA
1988 #define MOPT_Q          0
1989 #define MOPT_QFMT       0x0040
1990 #else
1991 #define MOPT_Q          MOPT_NOSUPPORT
1992 #define MOPT_QFMT       MOPT_NOSUPPORT
1993 #endif
1994 #define MOPT_DATAJ      0x0080
1995 #define MOPT_NO_EXT2    0x0100
1996 #define MOPT_NO_EXT3    0x0200
1997 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1998 #define MOPT_STRING     0x0400
1999 #define MOPT_SKIP       0x0800
2000 #define MOPT_2          0x1000
2001
2002 static const struct mount_opts {
2003         int     token;
2004         int     mount_opt;
2005         int     flags;
2006 } ext4_mount_opts[] = {
2007         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
2008         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
2009         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
2010         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
2011         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
2012         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
2013         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
2014          MOPT_EXT4_ONLY | MOPT_SET},
2015         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
2016          MOPT_EXT4_ONLY | MOPT_CLEAR},
2017         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
2018         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
2019         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
2020          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
2021         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
2022          MOPT_EXT4_ONLY | MOPT_CLEAR},
2023         {Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
2024         {Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
2025         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
2026          MOPT_EXT4_ONLY | MOPT_CLEAR},
2027         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
2028          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
2029         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
2030                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
2031          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
2032         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
2033         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
2034         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
2035         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
2036         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
2037          MOPT_NO_EXT2},
2038         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
2039          MOPT_NO_EXT2},
2040         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
2041         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
2042         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
2043         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
2044         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
2045         {Opt_commit, 0, MOPT_GTE0},
2046         {Opt_max_batch_time, 0, MOPT_GTE0},
2047         {Opt_min_batch_time, 0, MOPT_GTE0},
2048         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
2049         {Opt_init_itable, 0, MOPT_GTE0},
2050         {Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
2051         {Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
2052                 MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
2053         {Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
2054                 MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
2055         {Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
2056                 MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
2057         {Opt_stripe, 0, MOPT_GTE0},
2058         {Opt_resuid, 0, MOPT_GTE0},
2059         {Opt_resgid, 0, MOPT_GTE0},
2060         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
2061         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
2062         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
2063         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
2064         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
2065         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
2066          MOPT_NO_EXT2 | MOPT_DATAJ},
2067         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
2068         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
2069 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2070         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
2071         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
2072 #else
2073         {Opt_acl, 0, MOPT_NOSUPPORT},
2074         {Opt_noacl, 0, MOPT_NOSUPPORT},
2075 #endif
2076         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
2077         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
2078         {Opt_debug_want_extra_isize, 0, MOPT_GTE0},
2079         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
2080         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
2081                                                         MOPT_SET | MOPT_Q},
2082         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
2083                                                         MOPT_SET | MOPT_Q},
2084         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
2085                                                         MOPT_SET | MOPT_Q},
2086         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2087                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
2088                                                         MOPT_CLEAR | MOPT_Q},
2089         {Opt_usrjquota, 0, MOPT_Q | MOPT_STRING},
2090         {Opt_grpjquota, 0, MOPT_Q | MOPT_STRING},
2091         {Opt_offusrjquota, 0, MOPT_Q},
2092         {Opt_offgrpjquota, 0, MOPT_Q},
2093         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
2094         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
2095         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
2096         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
2097         {Opt_test_dummy_encryption, 0, MOPT_STRING},
2098         {Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
2099         {Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
2100          MOPT_SET},
2101         {Opt_mb_optimize_scan, EXT4_MOUNT2_MB_OPTIMIZE_SCAN, MOPT_GTE0},
2102 #ifdef CONFIG_EXT4_DEBUG
2103         {Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
2104          MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
2105         {Opt_fc_debug_max_replay, 0, MOPT_GTE0},
2106 #endif
2107         {Opt_err, 0, 0}
2108 };
2109
2110 #ifdef CONFIG_UNICODE
2111 static const struct ext4_sb_encodings {
2112         __u16 magic;
2113         char *name;
2114         char *version;
2115 } ext4_sb_encoding_map[] = {
2116         {EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
2117 };
2118
2119 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
2120                                  const struct ext4_sb_encodings **encoding,
2121                                  __u16 *flags)
2122 {
2123         __u16 magic = le16_to_cpu(es->s_encoding);
2124         int i;
2125
2126         for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
2127                 if (magic == ext4_sb_encoding_map[i].magic)
2128                         break;
2129
2130         if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
2131                 return -EINVAL;
2132
2133         *encoding = &ext4_sb_encoding_map[i];
2134         *flags = le16_to_cpu(es->s_encoding_flags);
2135
2136         return 0;
2137 }
2138 #endif
2139
2140 static int ext4_set_test_dummy_encryption(struct super_block *sb, char *arg)
2141 {
2142 #ifdef CONFIG_FS_ENCRYPTION
2143         struct ext4_sb_info *sbi = EXT4_SB(sb);
2144         int err;
2145
2146         err = fscrypt_set_test_dummy_encryption(sb, arg,
2147                                                 &sbi->s_dummy_enc_policy);
2148         if (err) {
2149                 ext4_msg(sb, KERN_WARNING,
2150                          "Error while setting test dummy encryption [%d]", err);
2151                 return err;
2152         }
2153         ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2154 #endif
2155         return 0;
2156 }
2157
2158 #define EXT4_SPEC_JQUOTA                        (1 <<  0)
2159 #define EXT4_SPEC_JQFMT                         (1 <<  1)
2160 #define EXT4_SPEC_DATAJ                         (1 <<  2)
2161 #define EXT4_SPEC_SB_BLOCK                      (1 <<  3)
2162 #define EXT4_SPEC_JOURNAL_DEV                   (1 <<  4)
2163 #define EXT4_SPEC_JOURNAL_IOPRIO                (1 <<  5)
2164 #define EXT4_SPEC_DUMMY_ENCRYPTION              (1 <<  6)
2165 #define EXT4_SPEC_s_want_extra_isize            (1 <<  7)
2166 #define EXT4_SPEC_s_max_batch_time              (1 <<  8)
2167 #define EXT4_SPEC_s_min_batch_time              (1 <<  9)
2168 #define EXT4_SPEC_s_inode_readahead_blks        (1 << 10)
2169 #define EXT4_SPEC_s_li_wait_mult                (1 << 11)
2170 #define EXT4_SPEC_s_max_dir_size_kb             (1 << 12)
2171 #define EXT4_SPEC_s_stripe                      (1 << 13)
2172 #define EXT4_SPEC_s_resuid                      (1 << 14)
2173 #define EXT4_SPEC_s_resgid                      (1 << 15)
2174 #define EXT4_SPEC_s_commit_interval             (1 << 16)
2175 #define EXT4_SPEC_s_fc_debug_max_replay         (1 << 17)
2176 #define EXT4_SPEC_s_sb_block                    (1 << 18)
2177
2178 struct ext4_fs_context {
2179         char            *s_qf_names[EXT4_MAXQUOTAS];
2180         char            *test_dummy_enc_arg;
2181         int             s_jquota_fmt;   /* Format of quota to use */
2182         int             mb_optimize_scan;
2183 #ifdef CONFIG_EXT4_DEBUG
2184         int s_fc_debug_max_replay;
2185 #endif
2186         unsigned short  qname_spec;
2187         unsigned long   vals_s_flags;   /* Bits to set in s_flags */
2188         unsigned long   mask_s_flags;   /* Bits changed in s_flags */
2189         unsigned long   journal_devnum;
2190         unsigned long   s_commit_interval;
2191         unsigned long   s_stripe;
2192         unsigned int    s_inode_readahead_blks;
2193         unsigned int    s_want_extra_isize;
2194         unsigned int    s_li_wait_mult;
2195         unsigned int    s_max_dir_size_kb;
2196         unsigned int    journal_ioprio;
2197         unsigned int    vals_s_mount_opt;
2198         unsigned int    mask_s_mount_opt;
2199         unsigned int    vals_s_mount_opt2;
2200         unsigned int    mask_s_mount_opt2;
2201         unsigned int    vals_s_mount_flags;
2202         unsigned int    mask_s_mount_flags;
2203         unsigned int    opt_flags;      /* MOPT flags */
2204         unsigned int    spec;
2205         u32             s_max_batch_time;
2206         u32             s_min_batch_time;
2207         kuid_t          s_resuid;
2208         kgid_t          s_resgid;
2209         ext4_fsblk_t    s_sb_block;
2210 };
2211
2212 static void ext4_fc_free(struct fs_context *fc)
2213 {
2214         struct ext4_fs_context *ctx = fc->fs_private;
2215         int i;
2216
2217         if (!ctx)
2218                 return;
2219
2220         for (i = 0; i < EXT4_MAXQUOTAS; i++)
2221                 kfree(ctx->s_qf_names[i]);
2222
2223         kfree(ctx->test_dummy_enc_arg);
2224         kfree(ctx);
2225 }
2226
2227 int ext4_init_fs_context(struct fs_context *fc)
2228 {
2229         struct xfs_fs_context   *ctx;
2230
2231         ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2232         if (!ctx)
2233                 return -ENOMEM;
2234
2235         fc->fs_private = ctx;
2236         fc->ops = &ext4_context_ops;
2237
2238         return 0;
2239 }
2240
2241 #ifdef CONFIG_QUOTA
2242 /*
2243  * Note the name of the specified quota file.
2244  */
2245 static int note_qf_name(struct fs_context *fc, int qtype,
2246                        struct fs_parameter *param)
2247 {
2248         struct ext4_fs_context *ctx = fc->fs_private;
2249         char *qname;
2250
2251         if (param->size < 1) {
2252                 ext4_msg(NULL, KERN_ERR, "Missing quota name");
2253                 return -EINVAL;
2254         }
2255         if (strchr(param->string, '/')) {
2256                 ext4_msg(NULL, KERN_ERR,
2257                          "quotafile must be on filesystem root");
2258                 return -EINVAL;
2259         }
2260         if (ctx->s_qf_names[qtype]) {
2261                 if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
2262                         ext4_msg(NULL, KERN_ERR,
2263                                  "%s quota file already specified",
2264                                  QTYPE2NAME(qtype));
2265                         return -EINVAL;
2266                 }
2267                 return 0;
2268         }
2269
2270         qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
2271         if (!qname) {
2272                 ext4_msg(NULL, KERN_ERR,
2273                          "Not enough memory for storing quotafile name");
2274                 return -ENOMEM;
2275         }
2276         ctx->s_qf_names[qtype] = qname;
2277         ctx->qname_spec |= 1 << qtype;
2278         ctx->spec |= EXT4_SPEC_JQUOTA;
2279         return 0;
2280 }
2281
2282 /*
2283  * Clear the name of the specified quota file.
2284  */
2285 static int unnote_qf_name(struct fs_context *fc, int qtype)
2286 {
2287         struct ext4_fs_context *ctx = fc->fs_private;
2288
2289         if (ctx->s_qf_names[qtype])
2290                 kfree(ctx->s_qf_names[qtype]);
2291
2292         ctx->s_qf_names[qtype] = NULL;
2293         ctx->qname_spec |= 1 << qtype;
2294         ctx->spec |= EXT4_SPEC_JQUOTA;
2295         return 0;
2296 }
2297 #endif
2298
2299 #define EXT4_SET_CTX(name)                                              \
2300 static inline void ctx_set_##name(struct ext4_fs_context *ctx, int flag)\
2301 {                                                                       \
2302         ctx->mask_s_##name |= flag;                                     \
2303         ctx->vals_s_##name |= flag;                                     \
2304 }                                                                       \
2305 static inline void ctx_clear_##name(struct ext4_fs_context *ctx, int flag)\
2306 {                                                                       \
2307         ctx->mask_s_##name |= flag;                                     \
2308         ctx->vals_s_##name &= ~flag;                                    \
2309 }                                                                       \
2310 static inline bool ctx_test_##name(struct ext4_fs_context *ctx, int flag)\
2311 {                                                                       \
2312         return ((ctx->vals_s_##name & flag) != 0);                      \
2313 }                                                                       \
2314
2315 EXT4_SET_CTX(flags);
2316 EXT4_SET_CTX(mount_opt);
2317 EXT4_SET_CTX(mount_opt2);
2318 EXT4_SET_CTX(mount_flags);
2319
2320 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2321 {
2322         struct ext4_fs_context *ctx = fc->fs_private;
2323         struct fs_parse_result result;
2324         const struct mount_opts *m;
2325         int is_remount;
2326         kuid_t uid;
2327         kgid_t gid;
2328         int token;
2329
2330         token = fs_parse(fc, ext4_param_specs, param, &result);
2331         if (token < 0)
2332                 return token;
2333         is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2334
2335 #ifdef CONFIG_QUOTA
2336         if (token == Opt_usrjquota) {
2337                 if (!*param->string)
2338                         return unnote_qf_name(fc, USRQUOTA);
2339                 else
2340                         return note_qf_name(fc, USRQUOTA, param);
2341         } else if (token == Opt_grpjquota) {
2342                 if (!*param->string)
2343                         return unnote_qf_name(fc, GRPQUOTA);
2344                 else
2345                         return note_qf_name(fc, GRPQUOTA, param);
2346         }
2347 #endif
2348         switch (token) {
2349         case Opt_noacl:
2350         case Opt_nouser_xattr:
2351                 ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "3.5");
2352                 break;
2353         case Opt_sb:
2354                 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2355                         ext4_msg(NULL, KERN_WARNING,
2356                                  "Ignoring %s option on remount", param->key);
2357                 } else {
2358                         ctx->s_sb_block = result.uint_32;
2359                         ctx->spec |= EXT4_SPEC_s_sb_block;
2360                 }
2361                 return 0;
2362         case Opt_removed:
2363                 ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2364                          param->key);
2365                 return 0;
2366         case Opt_abort:
2367                 ctx_set_mount_flags(ctx, EXT4_MF_FS_ABORTED);
2368                 return 0;
2369         case Opt_i_version:
2370                 ctx_set_flags(ctx, SB_I_VERSION);
2371                 return 0;
2372         case Opt_lazytime:
2373                 ctx_set_flags(ctx, SB_LAZYTIME);
2374                 return 0;
2375         case Opt_nolazytime:
2376                 ctx_clear_flags(ctx, SB_LAZYTIME);
2377                 return 0;
2378         case Opt_inlinecrypt:
2379 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2380                 ctx_set_flags(ctx, SB_INLINECRYPT);
2381 #else
2382                 ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2383 #endif
2384                 return 0;
2385         case Opt_errors:
2386         case Opt_data:
2387         case Opt_data_err:
2388         case Opt_jqfmt:
2389         case Opt_dax_type:
2390                 token = result.uint_32;
2391         }
2392
2393         for (m = ext4_mount_opts; m->token != Opt_err; m++)
2394                 if (token == m->token)
2395                         break;
2396
2397         ctx->opt_flags |= m->flags;
2398
2399         if (m->token == Opt_err) {
2400                 ext4_msg(NULL, KERN_ERR, "Unrecognized mount option \"%s\" "
2401                          "or missing value", param->key);
2402                 return -EINVAL;
2403         }
2404
2405         if (m->flags & MOPT_EXPLICIT) {
2406                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2407                         ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2408                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2409                         ctx_set_mount_opt2(ctx,
2410                                        EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2411                 } else
2412                         return -EINVAL;
2413         }
2414         if (m->flags & MOPT_CLEAR_ERR)
2415                 ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2416
2417         if (m->flags & MOPT_NOSUPPORT) {
2418                 ext4_msg(NULL, KERN_ERR, "%s option not supported",
2419                          param->key);
2420         } else if (token == Opt_commit) {
2421                 if (result.uint_32 == 0)
2422                         ctx->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE;
2423                 else if (result.uint_32 > INT_MAX / HZ) {
2424                         ext4_msg(NULL, KERN_ERR,
2425                                  "Invalid commit interval %d, "
2426                                  "must be smaller than %d",
2427                                  result.uint_32, INT_MAX / HZ);
2428                         return -EINVAL;
2429                 }
2430                 ctx->s_commit_interval = HZ * result.uint_32;
2431                 ctx->spec |= EXT4_SPEC_s_commit_interval;
2432         } else if (token == Opt_debug_want_extra_isize) {
2433                 if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2434                         ext4_msg(NULL, KERN_ERR,
2435                                  "Invalid want_extra_isize %d", result.uint_32);
2436                         return -EINVAL;
2437                 }
2438                 ctx->s_want_extra_isize = result.uint_32;
2439                 ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2440         } else if (token == Opt_max_batch_time) {
2441                 ctx->s_max_batch_time = result.uint_32;
2442                 ctx->spec |= EXT4_SPEC_s_max_batch_time;
2443         } else if (token == Opt_min_batch_time) {
2444                 ctx->s_min_batch_time = result.uint_32;
2445                 ctx->spec |= EXT4_SPEC_s_min_batch_time;
2446         } else if (token == Opt_inode_readahead_blks) {
2447                 if (result.uint_32 &&
2448                     (result.uint_32 > (1 << 30) ||
2449                      !is_power_of_2(result.uint_32))) {
2450                         ext4_msg(NULL, KERN_ERR,
2451                                  "EXT4-fs: inode_readahead_blks must be "
2452                                  "0 or a power of 2 smaller than 2^31");
2453                         return -EINVAL;
2454                 }
2455                 ctx->s_inode_readahead_blks = result.uint_32;
2456                 ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2457         } else if (token == Opt_init_itable) {
2458                 ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2459                 ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2460                 if (param->type == fs_value_is_string)
2461                         ctx->s_li_wait_mult = result.uint_32;
2462                 ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2463         } else if (token == Opt_max_dir_size_kb) {
2464                 ctx->s_max_dir_size_kb = result.uint_32;
2465                 ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2466 #ifdef CONFIG_EXT4_DEBUG
2467         } else if (token == Opt_fc_debug_max_replay) {
2468                 ctx->s_fc_debug_max_replay = result.uint_32;
2469                 ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2470 #endif
2471         } else if (token == Opt_stripe) {
2472                 ctx->s_stripe = result.uint_32;
2473                 ctx->spec |= EXT4_SPEC_s_stripe;
2474         } else if (token == Opt_resuid) {
2475                 uid = make_kuid(current_user_ns(), result.uint_32);
2476                 if (!uid_valid(uid)) {
2477                         ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2478                                  result.uint_32);
2479                         return -EINVAL;
2480                 }
2481                 ctx->s_resuid = uid;
2482                 ctx->spec |= EXT4_SPEC_s_resuid;
2483         } else if (token == Opt_resgid) {
2484                 gid = make_kgid(current_user_ns(), result.uint_32);
2485                 if (!gid_valid(gid)) {
2486                         ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2487                                  result.uint_32);
2488                         return -EINVAL;
2489                 }
2490                 ctx->s_resgid = gid;
2491                 ctx->spec |= EXT4_SPEC_s_resgid;
2492         } else if (token == Opt_journal_dev) {
2493                 if (is_remount) {
2494                         ext4_msg(NULL, KERN_ERR,
2495                                  "Cannot specify journal on remount");
2496                         return -EINVAL;
2497                 }
2498                 ctx->journal_devnum = result.uint_32;
2499                 ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2500         } else if (token == Opt_journal_path) {
2501                 struct inode *journal_inode;
2502                 struct path path;
2503                 int error;
2504
2505                 if (is_remount) {
2506                         ext4_msg(NULL, KERN_ERR,
2507                                  "Cannot specify journal on remount");
2508                         return -EINVAL;
2509                 }
2510
2511                 error = fs_lookup_param(fc, param, 1, &path);
2512                 if (error) {
2513                         ext4_msg(NULL, KERN_ERR, "error: could not find "
2514                                  "journal device path");
2515                         return -EINVAL;
2516                 }
2517
2518                 journal_inode = d_inode(path.dentry);
2519                 ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2520                 ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2521                 path_put(&path);
2522         } else if (token == Opt_journal_ioprio) {
2523                 if (result.uint_32 > 7) {
2524                         ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2525                                  " (must be 0-7)");
2526                         return -EINVAL;
2527                 }
2528                 ctx->journal_ioprio =
2529                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2530                 ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2531         } else if (token == Opt_test_dummy_encryption) {
2532 #ifdef CONFIG_FS_ENCRYPTION
2533                 if (param->type == fs_value_is_flag) {
2534                         ctx->spec |= EXT4_SPEC_DUMMY_ENCRYPTION;
2535                         ctx->test_dummy_enc_arg = NULL;
2536                         return 0;
2537                 }
2538                 if (*param->string &&
2539                     !(!strcmp(param->string, "v1") ||
2540                       !strcmp(param->string, "v2"))) {
2541                         ext4_msg(NULL, KERN_WARNING,
2542                                  "Value of option \"%s\" is unrecognized",
2543                                  param->key);
2544                         return -EINVAL;
2545                 }
2546                 ctx->spec |= EXT4_SPEC_DUMMY_ENCRYPTION;
2547                 ctx->test_dummy_enc_arg = kmemdup_nul(param->string, param->size,
2548                                                       GFP_KERNEL);
2549 #else
2550                 ext4_msg(NULL, KERN_WARNING,
2551                          "Test dummy encryption mount option ignored");
2552 #endif
2553         } else if (m->flags & MOPT_DATAJ) {
2554                 ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2555                 ctx_set_mount_opt(ctx, m->mount_opt);
2556                 ctx->spec |= EXT4_SPEC_DATAJ;
2557 #ifdef CONFIG_QUOTA
2558         } else if (m->flags & MOPT_QFMT) {
2559                 ctx->s_jquota_fmt = m->mount_opt;
2560                 ctx->spec |= EXT4_SPEC_JQFMT;
2561 #endif
2562         } else if (token == Opt_dax || token == Opt_dax_always ||
2563                    token == Opt_dax_inode || token == Opt_dax_never) {
2564 #ifdef CONFIG_FS_DAX
2565                 switch (token) {
2566                 case Opt_dax:
2567                 case Opt_dax_always:
2568                         ctx_set_mount_opt(ctx, m->mount_opt);
2569                         ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2570                         break;
2571                 case Opt_dax_never:
2572                         ctx_set_mount_opt2(ctx, m->mount_opt);
2573                         ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2574                         break;
2575                 case Opt_dax_inode:
2576                         ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2577                         ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2578                         /* Strictly for printing options */
2579                         ctx_set_mount_opt2(ctx, m->mount_opt);
2580                         break;
2581                 }
2582 #else
2583                 ext4_msg(NULL, KERN_INFO, "dax option not supported");
2584                 ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2585                 ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2586                 return -EINVAL;
2587 #endif
2588         } else if (token == Opt_data_err_abort) {
2589                 ctx_set_mount_opt(ctx, m->mount_opt);
2590         } else if (token == Opt_data_err_ignore) {
2591                 ctx_clear_mount_opt(ctx, m->mount_opt);
2592         } else if (token == Opt_mb_optimize_scan) {
2593                 if (result.int_32 != 0 && result.int_32 != 1) {
2594                         ext4_msg(NULL, KERN_WARNING,
2595                                  "mb_optimize_scan should be set to 0 or 1.");
2596                         return -EINVAL;
2597                 }
2598                 ctx->mb_optimize_scan = result.int_32;
2599         } else {
2600                 unsigned int set = 0;
2601
2602                 if ((param->type == fs_value_is_flag) ||
2603                     result.uint_32 > 0)
2604                         set = 1;
2605
2606                 if (m->flags & MOPT_CLEAR)
2607                         set = !set;
2608                 else if (unlikely(!(m->flags & MOPT_SET))) {
2609                         ext4_msg(NULL, KERN_WARNING,
2610                                  "buggy handling of option %s",
2611                                  param->key);
2612                         WARN_ON(1);
2613                         return -EINVAL;
2614                 }
2615                 if (m->flags & MOPT_2) {
2616                         if (set != 0)
2617                                 ctx_set_mount_opt2(ctx, m->mount_opt);
2618                         else
2619                                 ctx_clear_mount_opt2(ctx, m->mount_opt);
2620                 } else {
2621                         if (set != 0)
2622                                 ctx_set_mount_opt(ctx, m->mount_opt);
2623                         else
2624                                 ctx_clear_mount_opt(ctx, m->mount_opt);
2625                 }
2626         }
2627         return 0;
2628 }
2629
2630 static int parse_options(struct fs_context *fc, char *options)
2631 {
2632         struct fs_parameter param;
2633         int ret;
2634         char *key;
2635
2636         if (!options)
2637                 return 0;
2638
2639         while ((key = strsep(&options, ",")) != NULL) {
2640                 if (*key) {
2641                         size_t v_len = 0;
2642                         char *value = strchr(key, '=');
2643
2644                         param.type = fs_value_is_flag;
2645                         param.string = NULL;
2646
2647                         if (value) {
2648                                 if (value == key)
2649                                         continue;
2650
2651                                 *value++ = 0;
2652                                 v_len = strlen(value);
2653                                 param.string = kmemdup_nul(value, v_len,
2654                                                            GFP_KERNEL);
2655                                 if (!param.string)
2656                                         return -ENOMEM;
2657                                 param.type = fs_value_is_string;
2658                         }
2659
2660                         param.key = key;
2661                         param.size = v_len;
2662
2663                         ret = ext4_parse_param(fc, &param);
2664                         if (param.string)
2665                                 kfree(param.string);
2666                         if (ret < 0)
2667                                 return ret;
2668                 }
2669         }
2670
2671         ret = ext4_validate_options(fc);
2672         if (ret < 0)
2673                 return ret;
2674
2675         return 0;
2676 }
2677
2678 static int parse_apply_sb_mount_options(struct super_block *sb,
2679                                         struct ext4_fs_context *m_ctx)
2680 {
2681         struct ext4_sb_info *sbi = EXT4_SB(sb);
2682         char *s_mount_opts = NULL;
2683         struct ext4_fs_context *s_ctx = NULL;
2684         struct fs_context *fc = NULL;
2685         int ret = -ENOMEM;
2686
2687         if (!sbi->s_es->s_mount_opts[0])
2688                 return 0;
2689
2690         s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2691                                 sizeof(sbi->s_es->s_mount_opts),
2692                                 GFP_KERNEL);
2693         if (!s_mount_opts)
2694                 return ret;
2695
2696         fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2697         if (!fc)
2698                 goto out_free;
2699
2700         s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2701         if (!s_ctx)
2702                 goto out_free;
2703
2704         fc->fs_private = s_ctx;
2705         fc->s_fs_info = sbi;
2706
2707         ret = parse_options(fc, s_mount_opts);
2708         if (ret < 0)
2709                 goto parse_failed;
2710
2711         ret = ext4_check_opt_consistency(fc, sb);
2712         if (ret < 0) {
2713 parse_failed:
2714                 ext4_msg(sb, KERN_WARNING,
2715                          "failed to parse options in superblock: %s",
2716                          s_mount_opts);
2717                 ret = 0;
2718                 goto out_free;
2719         }
2720
2721         if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2722                 m_ctx->journal_devnum = s_ctx->journal_devnum;
2723         if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2724                 m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2725
2726         ret = ext4_apply_options(fc, sb);
2727
2728 out_free:
2729         kfree(s_ctx);
2730         kfree(fc);
2731         kfree(s_mount_opts);
2732         return ret;
2733 }
2734
2735 static void ext4_apply_quota_options(struct fs_context *fc,
2736                                      struct super_block *sb)
2737 {
2738 #ifdef CONFIG_QUOTA
2739         bool quota_feature = ext4_has_feature_quota(sb);
2740         struct ext4_fs_context *ctx = fc->fs_private;
2741         struct ext4_sb_info *sbi = EXT4_SB(sb);
2742         char *qname;
2743         int i;
2744
2745         if (quota_feature)
2746                 return;
2747
2748         if (ctx->spec & EXT4_SPEC_JQUOTA) {
2749                 for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2750                         if (!(ctx->qname_spec & (1 << i)))
2751                                 continue;
2752
2753                         qname = ctx->s_qf_names[i]; /* May be NULL */
2754                         ctx->s_qf_names[i] = NULL;
2755                         kfree(sbi->s_qf_names[i]);
2756                         rcu_assign_pointer(sbi->s_qf_names[i], qname);
2757                         set_opt(sb, QUOTA);
2758                 }
2759         }
2760
2761         if (ctx->spec & EXT4_SPEC_JQFMT)
2762                 sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2763 #endif
2764 }
2765
2766 /*
2767  * Check quota settings consistency.
2768  */
2769 static int ext4_check_quota_consistency(struct fs_context *fc,
2770                                         struct super_block *sb)
2771 {
2772 #ifdef CONFIG_QUOTA
2773         struct ext4_fs_context *ctx = fc->fs_private;
2774         struct ext4_sb_info *sbi = EXT4_SB(sb);
2775         bool quota_feature = ext4_has_feature_quota(sb);
2776         bool quota_loaded = sb_any_quota_loaded(sb);
2777         bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2778         int quota_flags, i;
2779
2780         /*
2781          * We do the test below only for project quotas. 'usrquota' and
2782          * 'grpquota' mount options are allowed even without quota feature
2783          * to support legacy quotas in quota files.
2784          */
2785         if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2786             !ext4_has_feature_project(sb)) {
2787                 ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2788                          "Cannot enable project quota enforcement.");
2789                 return -EINVAL;
2790         }
2791
2792         quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2793                       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2794         if (quota_loaded &&
2795             ctx->mask_s_mount_opt & quota_flags &&
2796             !ctx_test_mount_opt(ctx, quota_flags))
2797                 goto err_quota_change;
2798
2799         if (ctx->spec & EXT4_SPEC_JQUOTA) {
2800
2801                 for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2802                         if (!(ctx->qname_spec & (1 << i)))
2803                                 continue;
2804
2805                         if (quota_loaded &&
2806                             !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2807                                 goto err_jquota_change;
2808
2809                         if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2810                             strcmp(sbi->s_qf_names[i],
2811                                    ctx->s_qf_names[i]) != 0)
2812                                 goto err_jquota_specified;
2813                 }
2814
2815                 if (quota_feature) {
2816                         ext4_msg(NULL, KERN_INFO,
2817                                  "Journaled quota options ignored when "
2818                                  "QUOTA feature is enabled");
2819                         return 0;
2820                 }
2821         }
2822
2823         if (ctx->spec & EXT4_SPEC_JQFMT) {
2824                 if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2825                         goto err_jquota_change;
2826                 if (quota_feature) {
2827                         ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2828                                  "ignored when QUOTA feature is enabled");
2829                         return 0;
2830                 }
2831         }
2832
2833         /* Make sure we don't mix old and new quota format */
2834         usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2835                        ctx->s_qf_names[USRQUOTA]);
2836         grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2837                        ctx->s_qf_names[GRPQUOTA]);
2838
2839         usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2840                     test_opt(sb, USRQUOTA));
2841
2842         grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2843                     test_opt(sb, GRPQUOTA));
2844
2845         if (usr_qf_name) {
2846                 ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2847                 usrquota = false;
2848         }
2849         if (grp_qf_name) {
2850                 ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2851                 grpquota = false;
2852         }
2853
2854         if (usr_qf_name || grp_qf_name) {
2855                 if (usrquota || grpquota) {
2856                         ext4_msg(NULL, KERN_ERR, "old and new quota "
2857                                  "format mixing");
2858                         return -EINVAL;
2859                 }
2860
2861                 if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2862                         ext4_msg(NULL, KERN_ERR, "journaled quota format "
2863                                  "not specified");
2864                         return -EINVAL;
2865                 }
2866         }
2867
2868         return 0;
2869
2870 err_quota_change:
2871         ext4_msg(NULL, KERN_ERR,
2872                  "Cannot change quota options when quota turned on");
2873         return -EINVAL;
2874 err_jquota_change:
2875         ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2876                  "options when quota turned on");
2877         return -EINVAL;
2878 err_jquota_specified:
2879         ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2880                  QTYPE2NAME(i));
2881         return -EINVAL;
2882 #else
2883         return 0;
2884 #endif
2885 }
2886
2887 static int ext4_check_opt_consistency(struct fs_context *fc,
2888                                       struct super_block *sb)
2889 {
2890         struct ext4_fs_context *ctx = fc->fs_private;
2891         struct ext4_sb_info *sbi = fc->s_fs_info;
2892         int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2893
2894         if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2895                 ext4_msg(NULL, KERN_ERR,
2896                          "Mount option(s) incompatible with ext2");
2897                 return -EINVAL;
2898         }
2899         if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2900                 ext4_msg(NULL, KERN_ERR,
2901                          "Mount option(s) incompatible with ext3");
2902                 return -EINVAL;
2903         }
2904
2905         if (ctx->s_want_extra_isize >
2906             (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2907                 ext4_msg(NULL, KERN_ERR,
2908                          "Invalid want_extra_isize %d",
2909                          ctx->s_want_extra_isize);
2910                 return -EINVAL;
2911         }
2912
2913         if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2914                 int blocksize =
2915                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2916                 if (blocksize < PAGE_SIZE)
2917                         ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2918                                  "experimental mount option 'dioread_nolock' "
2919                                  "for blocksize < PAGE_SIZE");
2920         }
2921
2922 #ifdef CONFIG_FS_ENCRYPTION
2923         /*
2924          * This mount option is just for testing, and it's not worthwhile to
2925          * implement the extra complexity (e.g. RCU protection) that would be
2926          * needed to allow it to be set or changed during remount.  We do allow
2927          * it to be specified during remount, but only if there is no change.
2928          */
2929         if ((ctx->spec & EXT4_SPEC_DUMMY_ENCRYPTION) &&
2930             is_remount && !sbi->s_dummy_enc_policy.policy) {
2931                 ext4_msg(NULL, KERN_WARNING,
2932                          "Can't set test_dummy_encryption on remount");
2933                 return -1;
2934         }
2935 #endif
2936
2937         if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2938                 if (!sbi->s_journal) {
2939                         ext4_msg(NULL, KERN_WARNING,
2940                                  "Remounting file system with no journal "
2941                                  "so ignoring journalled data option");
2942                         ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2943                 } else if (ctx->mask_s_mount_opt & EXT4_MOUNT_DATA_FLAGS) {
2944                         ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2945                                  "on remount");
2946                         return -EINVAL;
2947                 }
2948         }
2949
2950         if (is_remount) {
2951                 if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2952                     (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2953                         ext4_msg(NULL, KERN_ERR, "can't mount with "
2954                                  "both data=journal and dax");
2955                         return -EINVAL;
2956                 }
2957
2958                 if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2959                     (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2960                      (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2961 fail_dax_change_remount:
2962                         ext4_msg(NULL, KERN_ERR, "can't change "
2963                                  "dax mount option while remounting");
2964                         return -EINVAL;
2965                 } else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2966                          (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2967                           (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2968                         goto fail_dax_change_remount;
2969                 } else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2970                            ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2971                             (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2972                             !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2973                         goto fail_dax_change_remount;
2974                 }
2975         }
2976
2977         return ext4_check_quota_consistency(fc, sb);
2978 }
2979
2980 static int ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2981 {
2982         struct ext4_fs_context *ctx = fc->fs_private;
2983         struct ext4_sb_info *sbi = fc->s_fs_info;
2984         int ret = 0;
2985
2986         sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2987         sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2988         sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2989         sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2990         sbi->s_mount_flags &= ~ctx->mask_s_mount_flags;
2991         sbi->s_mount_flags |= ctx->vals_s_mount_flags;
2992         sb->s_flags &= ~ctx->mask_s_flags;
2993         sb->s_flags |= ctx->vals_s_flags;
2994
2995 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2996         APPLY(s_commit_interval);
2997         APPLY(s_stripe);
2998         APPLY(s_max_batch_time);
2999         APPLY(s_min_batch_time);
3000         APPLY(s_want_extra_isize);
3001         APPLY(s_inode_readahead_blks);
3002         APPLY(s_max_dir_size_kb);
3003         APPLY(s_li_wait_mult);
3004         APPLY(s_resgid);
3005         APPLY(s_resuid);
3006
3007 #ifdef CONFIG_EXT4_DEBUG
3008         APPLY(s_fc_debug_max_replay);
3009 #endif
3010
3011         ext4_apply_quota_options(fc, sb);
3012
3013         if (ctx->spec & EXT4_SPEC_DUMMY_ENCRYPTION)
3014                 ret = ext4_set_test_dummy_encryption(sb, ctx->test_dummy_enc_arg);
3015
3016         return ret;
3017 }
3018
3019
3020 static int ext4_validate_options(struct fs_context *fc)
3021 {
3022 #ifdef CONFIG_QUOTA
3023         struct ext4_fs_context *ctx = fc->fs_private;
3024         char *usr_qf_name, *grp_qf_name;
3025
3026         usr_qf_name = ctx->s_qf_names[USRQUOTA];
3027         grp_qf_name = ctx->s_qf_names[GRPQUOTA];
3028
3029         if (usr_qf_name || grp_qf_name) {
3030                 if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
3031                         ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
3032
3033                 if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
3034                         ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
3035
3036                 if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
3037                     ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
3038                         ext4_msg(NULL, KERN_ERR, "old and new quota "
3039                                  "format mixing");
3040                         return -EINVAL;
3041                 }
3042         }
3043 #endif
3044         return 1;
3045 }
3046
3047 static inline void ext4_show_quota_options(struct seq_file *seq,
3048                                            struct super_block *sb)
3049 {
3050 #if defined(CONFIG_QUOTA)
3051         struct ext4_sb_info *sbi = EXT4_SB(sb);
3052         char *usr_qf_name, *grp_qf_name;
3053
3054         if (sbi->s_jquota_fmt) {
3055                 char *fmtname = "";
3056
3057                 switch (sbi->s_jquota_fmt) {
3058                 case QFMT_VFS_OLD:
3059                         fmtname = "vfsold";
3060                         break;
3061                 case QFMT_VFS_V0:
3062                         fmtname = "vfsv0";
3063                         break;
3064                 case QFMT_VFS_V1:
3065                         fmtname = "vfsv1";
3066                         break;
3067                 }
3068                 seq_printf(seq, ",jqfmt=%s", fmtname);
3069         }
3070
3071         rcu_read_lock();
3072         usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
3073         grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
3074         if (usr_qf_name)
3075                 seq_show_option(seq, "usrjquota", usr_qf_name);
3076         if (grp_qf_name)
3077                 seq_show_option(seq, "grpjquota", grp_qf_name);
3078         rcu_read_unlock();
3079 #endif
3080 }
3081
3082 static const char *token2str(int token)
3083 {
3084         const struct fs_parameter_spec *spec;
3085
3086         for (spec = ext4_param_specs; spec->name != NULL; spec++)
3087                 if (spec->opt == token && !spec->type)
3088                         break;
3089         return spec->name;
3090 }
3091
3092 /*
3093  * Show an option if
3094  *  - it's set to a non-default value OR
3095  *  - if the per-sb default is different from the global default
3096  */
3097 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
3098                               int nodefs)
3099 {
3100         struct ext4_sb_info *sbi = EXT4_SB(sb);
3101         struct ext4_super_block *es = sbi->s_es;
3102         int def_errors, def_mount_opt = sbi->s_def_mount_opt;
3103         const struct mount_opts *m;
3104         char sep = nodefs ? '\n' : ',';
3105
3106 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
3107 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
3108
3109         if (sbi->s_sb_block != 1)
3110                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
3111
3112         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
3113                 int want_set = m->flags & MOPT_SET;
3114                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
3115                     (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
3116                         continue;
3117                 if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
3118                         continue; /* skip if same as the default */
3119                 if ((want_set &&
3120                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
3121                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
3122                         continue; /* select Opt_noFoo vs Opt_Foo */
3123                 SEQ_OPTS_PRINT("%s", token2str(m->token));
3124         }
3125
3126         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
3127             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
3128                 SEQ_OPTS_PRINT("resuid=%u",
3129                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
3130         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
3131             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
3132                 SEQ_OPTS_PRINT("resgid=%u",
3133                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
3134         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
3135         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
3136                 SEQ_OPTS_PUTS("errors=remount-ro");
3137         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
3138                 SEQ_OPTS_PUTS("errors=continue");
3139         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
3140                 SEQ_OPTS_PUTS("errors=panic");
3141         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
3142                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
3143         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
3144                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
3145         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
3146                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
3147         if (sb->s_flags & SB_I_VERSION)
3148                 SEQ_OPTS_PUTS("i_version");
3149         if (nodefs || sbi->s_stripe)
3150                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
3151         if (nodefs || EXT4_MOUNT_DATA_FLAGS &
3152                         (sbi->s_mount_opt ^ def_mount_opt)) {
3153                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3154                         SEQ_OPTS_PUTS("data=journal");
3155                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3156                         SEQ_OPTS_PUTS("data=ordered");
3157                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
3158                         SEQ_OPTS_PUTS("data=writeback");
3159         }
3160         if (nodefs ||
3161             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
3162                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
3163                                sbi->s_inode_readahead_blks);
3164
3165         if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
3166                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
3167                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
3168         if (nodefs || sbi->s_max_dir_size_kb)
3169                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
3170         if (test_opt(sb, DATA_ERR_ABORT))
3171                 SEQ_OPTS_PUTS("data_err=abort");
3172
3173         fscrypt_show_test_dummy_encryption(seq, sep, sb);
3174
3175         if (sb->s_flags & SB_INLINECRYPT)
3176                 SEQ_OPTS_PUTS("inlinecrypt");
3177
3178         if (test_opt(sb, DAX_ALWAYS)) {
3179                 if (IS_EXT2_SB(sb))
3180                         SEQ_OPTS_PUTS("dax");
3181                 else
3182                         SEQ_OPTS_PUTS("dax=always");
3183         } else if (test_opt2(sb, DAX_NEVER)) {
3184                 SEQ_OPTS_PUTS("dax=never");
3185         } else if (test_opt2(sb, DAX_INODE)) {
3186                 SEQ_OPTS_PUTS("dax=inode");
3187         }
3188         ext4_show_quota_options(seq, sb);
3189         return 0;
3190 }
3191
3192 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3193 {
3194         return _ext4_show_options(seq, root->d_sb, 0);
3195 }
3196
3197 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3198 {
3199         struct super_block *sb = seq->private;
3200         int rc;
3201
3202         seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3203         rc = _ext4_show_options(seq, sb, 1);
3204         seq_puts(seq, "\n");
3205         return rc;
3206 }
3207
3208 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3209                             int read_only)
3210 {
3211         struct ext4_sb_info *sbi = EXT4_SB(sb);
3212         int err = 0;
3213
3214         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3215                 ext4_msg(sb, KERN_ERR, "revision level too high, "
3216                          "forcing read-only mode");
3217                 err = -EROFS;
3218                 goto done;
3219         }
3220         if (read_only)
3221                 goto done;
3222         if (!(sbi->s_mount_state & EXT4_VALID_FS))
3223                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3224                          "running e2fsck is recommended");
3225         else if (sbi->s_mount_state & EXT4_ERROR_FS)
3226                 ext4_msg(sb, KERN_WARNING,
3227                          "warning: mounting fs with errors, "
3228                          "running e2fsck is recommended");
3229         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3230                  le16_to_cpu(es->s_mnt_count) >=
3231                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3232                 ext4_msg(sb, KERN_WARNING,
3233                          "warning: maximal mount count reached, "
3234                          "running e2fsck is recommended");
3235         else if (le32_to_cpu(es->s_checkinterval) &&
3236                  (ext4_get_tstamp(es, s_lastcheck) +
3237                   le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3238                 ext4_msg(sb, KERN_WARNING,
3239                          "warning: checktime reached, "
3240                          "running e2fsck is recommended");
3241         if (!sbi->s_journal)
3242                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3243         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3244                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3245         le16_add_cpu(&es->s_mnt_count, 1);
3246         ext4_update_tstamp(es, s_mtime);
3247         if (sbi->s_journal) {
3248                 ext4_set_feature_journal_needs_recovery(sb);
3249                 if (ext4_has_feature_orphan_file(sb))
3250                         ext4_set_feature_orphan_present(sb);
3251         }
3252
3253         err = ext4_commit_super(sb);
3254 done:
3255         if (test_opt(sb, DEBUG))
3256                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3257                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3258                         sb->s_blocksize,
3259                         sbi->s_groups_count,
3260                         EXT4_BLOCKS_PER_GROUP(sb),
3261                         EXT4_INODES_PER_GROUP(sb),
3262                         sbi->s_mount_opt, sbi->s_mount_opt2);
3263
3264         cleancache_init_fs(sb);
3265         return err;
3266 }
3267
3268 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3269 {
3270         struct ext4_sb_info *sbi = EXT4_SB(sb);
3271         struct flex_groups **old_groups, **new_groups;
3272         int size, i, j;
3273
3274         if (!sbi->s_log_groups_per_flex)
3275                 return 0;
3276
3277         size = ext4_flex_group(sbi, ngroup - 1) + 1;
3278         if (size <= sbi->s_flex_groups_allocated)
3279                 return 0;
3280
3281         new_groups = kvzalloc(roundup_pow_of_two(size *
3282                               sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3283         if (!new_groups) {
3284                 ext4_msg(sb, KERN_ERR,
3285                          "not enough memory for %d flex group pointers", size);
3286                 return -ENOMEM;
3287         }
3288         for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3289                 new_groups[i] = kvzalloc(roundup_pow_of_two(
3290                                          sizeof(struct flex_groups)),
3291                                          GFP_KERNEL);
3292                 if (!new_groups[i]) {
3293                         for (j = sbi->s_flex_groups_allocated; j < i; j++)
3294                                 kvfree(new_groups[j]);
3295                         kvfree(new_groups);
3296                         ext4_msg(sb, KERN_ERR,
3297                                  "not enough memory for %d flex groups", size);
3298                         return -ENOMEM;
3299                 }
3300         }
3301         rcu_read_lock();
3302         old_groups = rcu_dereference(sbi->s_flex_groups);
3303         if (old_groups)
3304                 memcpy(new_groups, old_groups,
3305                        (sbi->s_flex_groups_allocated *
3306                         sizeof(struct flex_groups *)));
3307         rcu_read_unlock();
3308         rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3309         sbi->s_flex_groups_allocated = size;
3310         if (old_groups)
3311                 ext4_kvfree_array_rcu(old_groups);
3312         return 0;
3313 }
3314
3315 static int ext4_fill_flex_info(struct super_block *sb)
3316 {
3317         struct ext4_sb_info *sbi = EXT4_SB(sb);
3318         struct ext4_group_desc *gdp = NULL;
3319         struct flex_groups *fg;
3320         ext4_group_t flex_group;
3321         int i, err;
3322
3323         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3324         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3325                 sbi->s_log_groups_per_flex = 0;
3326                 return 1;
3327         }
3328
3329         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3330         if (err)
3331                 goto failed;
3332
3333         for (i = 0; i < sbi->s_groups_count; i++) {
3334                 gdp = ext4_get_group_desc(sb, i, NULL);
3335
3336                 flex_group = ext4_flex_group(sbi, i);
3337                 fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3338                 atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3339                 atomic64_add(ext4_free_group_clusters(sb, gdp),
3340                              &fg->free_clusters);
3341                 atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3342         }
3343
3344         return 1;
3345 failed:
3346         return 0;
3347 }
3348
3349 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3350                                    struct ext4_group_desc *gdp)
3351 {
3352         int offset = offsetof(struct ext4_group_desc, bg_checksum);
3353         __u16 crc = 0;
3354         __le32 le_group = cpu_to_le32(block_group);
3355         struct ext4_sb_info *sbi = EXT4_SB(sb);
3356
3357         if (ext4_has_metadata_csum(sbi->s_sb)) {
3358                 /* Use new metadata_csum algorithm */
3359                 __u32 csum32;
3360                 __u16 dummy_csum = 0;
3361
3362                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3363                                      sizeof(le_group));
3364                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3365                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3366                                      sizeof(dummy_csum));
3367                 offset += sizeof(dummy_csum);
3368                 if (offset < sbi->s_desc_size)
3369                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3370                                              sbi->s_desc_size - offset);
3371
3372                 crc = csum32 & 0xFFFF;
3373                 goto out;
3374         }
3375
3376         /* old crc16 code */
3377         if (!ext4_has_feature_gdt_csum(sb))
3378                 return 0;
3379
3380         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3381         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3382         crc = crc16(crc, (__u8 *)gdp, offset);
3383         offset += sizeof(gdp->bg_checksum); /* skip checksum */
3384         /* for checksum of struct ext4_group_desc do the rest...*/
3385         if (ext4_has_feature_64bit(sb) &&
3386             offset < le16_to_cpu(sbi->s_es->s_desc_size))
3387                 crc = crc16(crc, (__u8 *)gdp + offset,
3388                             le16_to_cpu(sbi->s_es->s_desc_size) -
3389                                 offset);
3390
3391 out:
3392         return cpu_to_le16(crc);
3393 }
3394
3395 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3396                                 struct ext4_group_desc *gdp)
3397 {
3398         if (ext4_has_group_desc_csum(sb) &&
3399             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3400                 return 0;
3401
3402         return 1;
3403 }
3404
3405 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3406                               struct ext4_group_desc *gdp)
3407 {
3408         if (!ext4_has_group_desc_csum(sb))
3409                 return;
3410         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3411 }
3412
3413 /* Called at mount-time, super-block is locked */
3414 static int ext4_check_descriptors(struct super_block *sb,
3415                                   ext4_fsblk_t sb_block,
3416                                   ext4_group_t *first_not_zeroed)
3417 {
3418         struct ext4_sb_info *sbi = EXT4_SB(sb);
3419         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3420         ext4_fsblk_t last_block;
3421         ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3422         ext4_fsblk_t block_bitmap;
3423         ext4_fsblk_t inode_bitmap;
3424         ext4_fsblk_t inode_table;
3425         int flexbg_flag = 0;
3426         ext4_group_t i, grp = sbi->s_groups_count;
3427
3428         if (ext4_has_feature_flex_bg(sb))
3429                 flexbg_flag = 1;
3430
3431         ext4_debug("Checking group descriptors");
3432
3433         for (i = 0; i < sbi->s_groups_count; i++) {
3434                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3435
3436                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
3437                         last_block = ext4_blocks_count(sbi->s_es) - 1;
3438                 else
3439                         last_block = first_block +
3440                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
3441
3442                 if ((grp == sbi->s_groups_count) &&
3443                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3444                         grp = i;
3445
3446                 block_bitmap = ext4_block_bitmap(sb, gdp);
3447                 if (block_bitmap == sb_block) {
3448                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3449                                  "Block bitmap for group %u overlaps "
3450                                  "superblock", i);
3451                         if (!sb_rdonly(sb))
3452                                 return 0;
3453                 }
3454                 if (block_bitmap >= sb_block + 1 &&
3455                     block_bitmap <= last_bg_block) {
3456                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3457                                  "Block bitmap for group %u overlaps "
3458                                  "block group descriptors", i);
3459                         if (!sb_rdonly(sb))
3460                                 return 0;
3461                 }
3462                 if (block_bitmap < first_block || block_bitmap > last_block) {
3463                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3464                                "Block bitmap for group %u not in group "
3465                                "(block %llu)!", i, block_bitmap);
3466                         return 0;
3467                 }
3468                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
3469                 if (inode_bitmap == sb_block) {
3470                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3471                                  "Inode bitmap for group %u overlaps "
3472                                  "superblock", i);
3473                         if (!sb_rdonly(sb))
3474                                 return 0;
3475                 }
3476                 if (inode_bitmap >= sb_block + 1 &&
3477                     inode_bitmap <= last_bg_block) {
3478                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3479                                  "Inode bitmap for group %u overlaps "
3480                                  "block group descriptors", i);
3481                         if (!sb_rdonly(sb))
3482                                 return 0;
3483                 }
3484                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
3485                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3486                                "Inode bitmap for group %u not in group "
3487                                "(block %llu)!", i, inode_bitmap);
3488                         return 0;
3489                 }
3490                 inode_table = ext4_inode_table(sb, gdp);
3491                 if (inode_table == sb_block) {
3492                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3493                                  "Inode table for group %u overlaps "
3494                                  "superblock", i);
3495                         if (!sb_rdonly(sb))
3496                                 return 0;
3497                 }
3498                 if (inode_table >= sb_block + 1 &&
3499                     inode_table <= last_bg_block) {
3500                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3501                                  "Inode table for group %u overlaps "
3502                                  "block group descriptors", i);
3503                         if (!sb_rdonly(sb))
3504                                 return 0;
3505                 }
3506                 if (inode_table < first_block ||
3507                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
3508                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3509                                "Inode table for group %u not in group "
3510                                "(block %llu)!", i, inode_table);
3511                         return 0;
3512                 }
3513                 ext4_lock_group(sb, i);
3514                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3515                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3516                                  "Checksum for group %u failed (%u!=%u)",
3517                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3518                                      gdp)), le16_to_cpu(gdp->bg_checksum));
3519                         if (!sb_rdonly(sb)) {
3520                                 ext4_unlock_group(sb, i);
3521                                 return 0;
3522                         }
3523                 }
3524                 ext4_unlock_group(sb, i);
3525                 if (!flexbg_flag)
3526                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
3527         }
3528         if (NULL != first_not_zeroed)
3529                 *first_not_zeroed = grp;
3530         return 1;
3531 }
3532
3533 /*
3534  * Maximal extent format file size.
3535  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3536  * extent format containers, within a sector_t, and within i_blocks
3537  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3538  * so that won't be a limiting factor.
3539  *
3540  * However there is other limiting factor. We do store extents in the form
3541  * of starting block and length, hence the resulting length of the extent
3542  * covering maximum file size must fit into on-disk format containers as
3543  * well. Given that length is always by 1 unit bigger than max unit (because
3544  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3545  *
3546  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3547  */
3548 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3549 {
3550         loff_t res;
3551         loff_t upper_limit = MAX_LFS_FILESIZE;
3552
3553         BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3554
3555         if (!has_huge_files) {
3556                 upper_limit = (1LL << 32) - 1;
3557
3558                 /* total blocks in file system block size */
3559                 upper_limit >>= (blkbits - 9);
3560                 upper_limit <<= blkbits;
3561         }
3562
3563         /*
3564          * 32-bit extent-start container, ee_block. We lower the maxbytes
3565          * by one fs block, so ee_len can cover the extent of maximum file
3566          * size
3567          */
3568         res = (1LL << 32) - 1;
3569         res <<= blkbits;
3570
3571         /* Sanity check against vm- & vfs- imposed limits */
3572         if (res > upper_limit)
3573                 res = upper_limit;
3574
3575         return res;
3576 }
3577
3578 /*
3579  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3580  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3581  * We need to be 1 filesystem block less than the 2^48 sector limit.
3582  */
3583 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3584 {
3585         unsigned long long upper_limit, res = EXT4_NDIR_BLOCKS;
3586         int meta_blocks;
3587
3588         /*
3589          * This is calculated to be the largest file size for a dense, block
3590          * mapped file such that the file's total number of 512-byte sectors,
3591          * including data and all indirect blocks, does not exceed (2^48 - 1).
3592          *
3593          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3594          * number of 512-byte sectors of the file.
3595          */
3596         if (!has_huge_files) {
3597                 /*
3598                  * !has_huge_files or implies that the inode i_block field
3599                  * represents total file blocks in 2^32 512-byte sectors ==
3600                  * size of vfs inode i_blocks * 8
3601                  */
3602                 upper_limit = (1LL << 32) - 1;
3603
3604                 /* total blocks in file system block size */
3605                 upper_limit >>= (bits - 9);
3606
3607         } else {
3608                 /*
3609                  * We use 48 bit ext4_inode i_blocks
3610                  * With EXT4_HUGE_FILE_FL set the i_blocks
3611                  * represent total number of blocks in
3612                  * file system block size
3613                  */
3614                 upper_limit = (1LL << 48) - 1;
3615
3616         }
3617
3618         /* indirect blocks */
3619         meta_blocks = 1;
3620         /* double indirect blocks */
3621         meta_blocks += 1 + (1LL << (bits-2));
3622         /* tripple indirect blocks */
3623         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
3624
3625         upper_limit -= meta_blocks;
3626         upper_limit <<= bits;
3627
3628         res += 1LL << (bits-2);
3629         res += 1LL << (2*(bits-2));
3630         res += 1LL << (3*(bits-2));
3631         res <<= bits;
3632         if (res > upper_limit)
3633                 res = upper_limit;
3634
3635         if (res > MAX_LFS_FILESIZE)
3636                 res = MAX_LFS_FILESIZE;
3637
3638         return (loff_t)res;
3639 }
3640
3641 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3642                                    ext4_fsblk_t logical_sb_block, int nr)
3643 {
3644         struct ext4_sb_info *sbi = EXT4_SB(sb);
3645         ext4_group_t bg, first_meta_bg;
3646         int has_super = 0;
3647
3648         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3649
3650         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3651                 return logical_sb_block + nr + 1;
3652         bg = sbi->s_desc_per_block * nr;
3653         if (ext4_bg_has_super(sb, bg))
3654                 has_super = 1;
3655
3656         /*
3657          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3658          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3659          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3660          * compensate.
3661          */
3662         if (sb->s_blocksize == 1024 && nr == 0 &&
3663             le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3664                 has_super++;
3665
3666         return (has_super + ext4_group_first_block_no(sb, bg));
3667 }
3668
3669 /**
3670  * ext4_get_stripe_size: Get the stripe size.
3671  * @sbi: In memory super block info
3672  *
3673  * If we have specified it via mount option, then
3674  * use the mount option value. If the value specified at mount time is
3675  * greater than the blocks per group use the super block value.
3676  * If the super block value is greater than blocks per group return 0.
3677  * Allocator needs it be less than blocks per group.
3678  *
3679  */
3680 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3681 {
3682         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3683         unsigned long stripe_width =
3684                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3685         int ret;
3686
3687         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3688                 ret = sbi->s_stripe;
3689         else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3690                 ret = stripe_width;
3691         else if (stride && stride <= sbi->s_blocks_per_group)
3692                 ret = stride;
3693         else
3694                 ret = 0;
3695
3696         /*
3697          * If the stripe width is 1, this makes no sense and
3698          * we set it to 0 to turn off stripe handling code.
3699          */
3700         if (ret <= 1)
3701                 ret = 0;
3702
3703         return ret;
3704 }
3705
3706 /*
3707  * Check whether this filesystem can be mounted based on
3708  * the features present and the RDONLY/RDWR mount requested.
3709  * Returns 1 if this filesystem can be mounted as requested,
3710  * 0 if it cannot be.
3711  */
3712 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3713 {
3714         if (ext4_has_unknown_ext4_incompat_features(sb)) {
3715                 ext4_msg(sb, KERN_ERR,
3716                         "Couldn't mount because of "
3717                         "unsupported optional features (%x)",
3718                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3719                         ~EXT4_FEATURE_INCOMPAT_SUPP));
3720                 return 0;
3721         }
3722
3723 #ifndef CONFIG_UNICODE
3724         if (ext4_has_feature_casefold(sb)) {
3725                 ext4_msg(sb, KERN_ERR,
3726                          "Filesystem with casefold feature cannot be "
3727                          "mounted without CONFIG_UNICODE");
3728                 return 0;
3729         }
3730 #endif
3731
3732         if (readonly)
3733                 return 1;
3734
3735         if (ext4_has_feature_readonly(sb)) {
3736                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3737                 sb->s_flags |= SB_RDONLY;
3738                 return 1;
3739         }
3740
3741         /* Check that feature set is OK for a read-write mount */
3742         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3743                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3744                          "unsupported optional features (%x)",
3745                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3746                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
3747                 return 0;
3748         }
3749         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3750                 ext4_msg(sb, KERN_ERR,
3751                          "Can't support bigalloc feature without "
3752                          "extents feature\n");
3753                 return 0;
3754         }
3755
3756 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3757         if (!readonly && (ext4_has_feature_quota(sb) ||
3758                           ext4_has_feature_project(sb))) {
3759                 ext4_msg(sb, KERN_ERR,
3760                          "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3761                 return 0;
3762         }
3763 #endif  /* CONFIG_QUOTA */
3764         return 1;
3765 }
3766
3767 /*
3768  * This function is called once a day if we have errors logged
3769  * on the file system
3770  */
3771 static void print_daily_error_info(struct timer_list *t)
3772 {
3773         struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3774         struct super_block *sb = sbi->s_sb;
3775         struct ext4_super_block *es = sbi->s_es;
3776
3777         if (es->s_error_count)
3778                 /* fsck newer than v1.41.13 is needed to clean this condition. */
3779                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3780                          le32_to_cpu(es->s_error_count));
3781         if (es->s_first_error_time) {
3782                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3783                        sb->s_id,
3784                        ext4_get_tstamp(es, s_first_error_time),
3785                        (int) sizeof(es->s_first_error_func),
3786                        es->s_first_error_func,
3787                        le32_to_cpu(es->s_first_error_line));
3788                 if (es->s_first_error_ino)
3789                         printk(KERN_CONT ": inode %u",
3790                                le32_to_cpu(es->s_first_error_ino));
3791                 if (es->s_first_error_block)
3792                         printk(KERN_CONT ": block %llu", (unsigned long long)
3793                                le64_to_cpu(es->s_first_error_block));
3794                 printk(KERN_CONT "\n");
3795         }
3796         if (es->s_last_error_time) {
3797                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3798                        sb->s_id,
3799                        ext4_get_tstamp(es, s_last_error_time),
3800                        (int) sizeof(es->s_last_error_func),
3801                        es->s_last_error_func,
3802                        le32_to_cpu(es->s_last_error_line));
3803                 if (es->s_last_error_ino)
3804                         printk(KERN_CONT ": inode %u",
3805                                le32_to_cpu(es->s_last_error_ino));
3806                 if (es->s_last_error_block)
3807                         printk(KERN_CONT ": block %llu", (unsigned long long)
3808                                le64_to_cpu(es->s_last_error_block));
3809                 printk(KERN_CONT "\n");
3810         }
3811         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3812 }
3813
3814 /* Find next suitable group and run ext4_init_inode_table */
3815 static int ext4_run_li_request(struct ext4_li_request *elr)
3816 {
3817         struct ext4_group_desc *gdp = NULL;
3818         struct super_block *sb = elr->lr_super;
3819         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3820         ext4_group_t group = elr->lr_next_group;
3821         unsigned int prefetch_ios = 0;
3822         int ret = 0;
3823         u64 start_time;
3824
3825         if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3826                 elr->lr_next_group = ext4_mb_prefetch(sb, group,
3827                                 EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3828                 if (prefetch_ios)
3829                         ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3830                                               prefetch_ios);
3831                 trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3832                                             prefetch_ios);
3833                 if (group >= elr->lr_next_group) {
3834                         ret = 1;
3835                         if (elr->lr_first_not_zeroed != ngroups &&
3836                             !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3837                                 elr->lr_next_group = elr->lr_first_not_zeroed;
3838                                 elr->lr_mode = EXT4_LI_MODE_ITABLE;
3839                                 ret = 0;
3840                         }
3841                 }
3842                 return ret;
3843         }
3844
3845         for (; group < ngroups; group++) {
3846                 gdp = ext4_get_group_desc(sb, group, NULL);
3847                 if (!gdp) {
3848                         ret = 1;
3849                         break;
3850                 }
3851
3852                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3853                         break;
3854         }
3855
3856         if (group >= ngroups)
3857                 ret = 1;
3858
3859         if (!ret) {
3860                 start_time = ktime_get_real_ns();
3861                 ret = ext4_init_inode_table(sb, group,
3862                                             elr->lr_timeout ? 0 : 1);
3863                 trace_ext4_lazy_itable_init(sb, group);
3864                 if (elr->lr_timeout == 0) {
3865                         elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3866                                 EXT4_SB(elr->lr_super)->s_li_wait_mult);
3867                 }
3868                 elr->lr_next_sched = jiffies + elr->lr_timeout;
3869                 elr->lr_next_group = group + 1;
3870         }
3871         return ret;
3872 }
3873
3874 /*
3875  * Remove lr_request from the list_request and free the
3876  * request structure. Should be called with li_list_mtx held
3877  */
3878 static void ext4_remove_li_request(struct ext4_li_request *elr)
3879 {
3880         if (!elr)
3881                 return;
3882
3883         list_del(&elr->lr_request);
3884         EXT4_SB(elr->lr_super)->s_li_request = NULL;
3885         kfree(elr);
3886 }
3887
3888 static void ext4_unregister_li_request(struct super_block *sb)
3889 {
3890         mutex_lock(&ext4_li_mtx);
3891         if (!ext4_li_info) {
3892                 mutex_unlock(&ext4_li_mtx);
3893                 return;
3894         }
3895
3896         mutex_lock(&ext4_li_info->li_list_mtx);
3897         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3898         mutex_unlock(&ext4_li_info->li_list_mtx);
3899         mutex_unlock(&ext4_li_mtx);
3900 }
3901
3902 static struct task_struct *ext4_lazyinit_task;
3903
3904 /*
3905  * This is the function where ext4lazyinit thread lives. It walks
3906  * through the request list searching for next scheduled filesystem.
3907  * When such a fs is found, run the lazy initialization request
3908  * (ext4_rn_li_request) and keep track of the time spend in this
3909  * function. Based on that time we compute next schedule time of
3910  * the request. When walking through the list is complete, compute
3911  * next waking time and put itself into sleep.
3912  */
3913 static int ext4_lazyinit_thread(void *arg)
3914 {
3915         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3916         struct list_head *pos, *n;
3917         struct ext4_li_request *elr;
3918         unsigned long next_wakeup, cur;
3919
3920         BUG_ON(NULL == eli);
3921
3922 cont_thread:
3923         while (true) {
3924                 next_wakeup = MAX_JIFFY_OFFSET;
3925
3926                 mutex_lock(&eli->li_list_mtx);
3927                 if (list_empty(&eli->li_request_list)) {
3928                         mutex_unlock(&eli->li_list_mtx);
3929                         goto exit_thread;
3930                 }
3931                 list_for_each_safe(pos, n, &eli->li_request_list) {
3932                         int err = 0;
3933                         int progress = 0;
3934                         elr = list_entry(pos, struct ext4_li_request,
3935                                          lr_request);
3936
3937                         if (time_before(jiffies, elr->lr_next_sched)) {
3938                                 if (time_before(elr->lr_next_sched, next_wakeup))
3939                                         next_wakeup = elr->lr_next_sched;
3940                                 continue;
3941                         }
3942                         if (down_read_trylock(&elr->lr_super->s_umount)) {
3943                                 if (sb_start_write_trylock(elr->lr_super)) {
3944                                         progress = 1;
3945                                         /*
3946                                          * We hold sb->s_umount, sb can not
3947                                          * be removed from the list, it is
3948                                          * now safe to drop li_list_mtx
3949                                          */
3950                                         mutex_unlock(&eli->li_list_mtx);
3951                                         err = ext4_run_li_request(elr);
3952                                         sb_end_write(elr->lr_super);
3953                                         mutex_lock(&eli->li_list_mtx);
3954                                         n = pos->next;
3955                                 }
3956                                 up_read((&elr->lr_super->s_umount));
3957                         }
3958                         /* error, remove the lazy_init job */
3959                         if (err) {
3960                                 ext4_remove_li_request(elr);
3961                                 continue;
3962                         }
3963                         if (!progress) {
3964                                 elr->lr_next_sched = jiffies +
3965                                         (prandom_u32()
3966                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3967                         }
3968                         if (time_before(elr->lr_next_sched, next_wakeup))
3969                                 next_wakeup = elr->lr_next_sched;
3970                 }
3971                 mutex_unlock(&eli->li_list_mtx);
3972
3973                 try_to_freeze();
3974
3975                 cur = jiffies;
3976                 if ((time_after_eq(cur, next_wakeup)) ||
3977                     (MAX_JIFFY_OFFSET == next_wakeup)) {
3978                         cond_resched();
3979                         continue;
3980                 }
3981
3982                 schedule_timeout_interruptible(next_wakeup - cur);
3983
3984                 if (kthread_should_stop()) {
3985                         ext4_clear_request_list();
3986                         goto exit_thread;
3987                 }
3988         }
3989
3990 exit_thread:
3991         /*
3992          * It looks like the request list is empty, but we need
3993          * to check it under the li_list_mtx lock, to prevent any
3994          * additions into it, and of course we should lock ext4_li_mtx
3995          * to atomically free the list and ext4_li_info, because at
3996          * this point another ext4 filesystem could be registering
3997          * new one.
3998          */
3999         mutex_lock(&ext4_li_mtx);
4000         mutex_lock(&eli->li_list_mtx);
4001         if (!list_empty(&eli->li_request_list)) {
4002                 mutex_unlock(&eli->li_list_mtx);
4003                 mutex_unlock(&ext4_li_mtx);
4004                 goto cont_thread;
4005         }
4006         mutex_unlock(&eli->li_list_mtx);
4007         kfree(ext4_li_info);
4008         ext4_li_info = NULL;
4009         mutex_unlock(&ext4_li_mtx);
4010
4011         return 0;
4012 }
4013
4014 static void ext4_clear_request_list(void)
4015 {
4016         struct list_head *pos, *n;
4017         struct ext4_li_request *elr;
4018
4019         mutex_lock(&ext4_li_info->li_list_mtx);
4020         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
4021                 elr = list_entry(pos, struct ext4_li_request,
4022                                  lr_request);
4023                 ext4_remove_li_request(elr);
4024         }
4025         mutex_unlock(&ext4_li_info->li_list_mtx);
4026 }
4027
4028 static int ext4_run_lazyinit_thread(void)
4029 {
4030         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
4031                                          ext4_li_info, "ext4lazyinit");
4032         if (IS_ERR(ext4_lazyinit_task)) {
4033                 int err = PTR_ERR(ext4_lazyinit_task);
4034                 ext4_clear_request_list();
4035                 kfree(ext4_li_info);
4036                 ext4_li_info = NULL;
4037                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
4038                                  "initialization thread\n",
4039                                  err);
4040                 return err;
4041         }
4042         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
4043         return 0;
4044 }
4045
4046 /*
4047  * Check whether it make sense to run itable init. thread or not.
4048  * If there is at least one uninitialized inode table, return
4049  * corresponding group number, else the loop goes through all
4050  * groups and return total number of groups.
4051  */
4052 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
4053 {
4054         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
4055         struct ext4_group_desc *gdp = NULL;
4056
4057         if (!ext4_has_group_desc_csum(sb))
4058                 return ngroups;
4059
4060         for (group = 0; group < ngroups; group++) {
4061                 gdp = ext4_get_group_desc(sb, group, NULL);
4062                 if (!gdp)
4063                         continue;
4064
4065                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
4066                         break;
4067         }
4068
4069         return group;
4070 }
4071
4072 static int ext4_li_info_new(void)
4073 {
4074         struct ext4_lazy_init *eli = NULL;
4075
4076         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
4077         if (!eli)
4078                 return -ENOMEM;
4079
4080         INIT_LIST_HEAD(&eli->li_request_list);
4081         mutex_init(&eli->li_list_mtx);
4082
4083         eli->li_state |= EXT4_LAZYINIT_QUIT;
4084
4085         ext4_li_info = eli;
4086
4087         return 0;
4088 }
4089
4090 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
4091                                             ext4_group_t start)
4092 {
4093         struct ext4_li_request *elr;
4094
4095         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
4096         if (!elr)
4097                 return NULL;
4098
4099         elr->lr_super = sb;
4100         elr->lr_first_not_zeroed = start;
4101         if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
4102                 elr->lr_mode = EXT4_LI_MODE_ITABLE;
4103                 elr->lr_next_group = start;
4104         } else {
4105                 elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
4106         }
4107
4108         /*
4109          * Randomize first schedule time of the request to
4110          * spread the inode table initialization requests
4111          * better.
4112          */
4113         elr->lr_next_sched = jiffies + (prandom_u32() %
4114                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
4115         return elr;
4116 }
4117
4118 int ext4_register_li_request(struct super_block *sb,
4119                              ext4_group_t first_not_zeroed)
4120 {
4121         struct ext4_sb_info *sbi = EXT4_SB(sb);
4122         struct ext4_li_request *elr = NULL;
4123         ext4_group_t ngroups = sbi->s_groups_count;
4124         int ret = 0;
4125
4126         mutex_lock(&ext4_li_mtx);
4127         if (sbi->s_li_request != NULL) {
4128                 /*
4129                  * Reset timeout so it can be computed again, because
4130                  * s_li_wait_mult might have changed.
4131                  */
4132                 sbi->s_li_request->lr_timeout = 0;
4133                 goto out;
4134         }
4135
4136         if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
4137             (first_not_zeroed == ngroups || sb_rdonly(sb) ||
4138              !test_opt(sb, INIT_INODE_TABLE)))
4139                 goto out;
4140
4141         elr = ext4_li_request_new(sb, first_not_zeroed);
4142         if (!elr) {
4143                 ret = -ENOMEM;
4144                 goto out;
4145         }
4146
4147         if (NULL == ext4_li_info) {
4148                 ret = ext4_li_info_new();
4149                 if (ret)
4150                         goto out;
4151         }
4152
4153         mutex_lock(&ext4_li_info->li_list_mtx);
4154         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4155         mutex_unlock(&ext4_li_info->li_list_mtx);
4156
4157         sbi->s_li_request = elr;
4158         /*
4159          * set elr to NULL here since it has been inserted to
4160          * the request_list and the removal and free of it is
4161          * handled by ext4_clear_request_list from now on.
4162          */
4163         elr = NULL;
4164
4165         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4166                 ret = ext4_run_lazyinit_thread();
4167                 if (ret)
4168                         goto out;
4169         }
4170 out:
4171         mutex_unlock(&ext4_li_mtx);
4172         if (ret)
4173                 kfree(elr);
4174         return ret;
4175 }
4176
4177 /*
4178  * We do not need to lock anything since this is called on
4179  * module unload.
4180  */
4181 static void ext4_destroy_lazyinit_thread(void)
4182 {
4183         /*
4184          * If thread exited earlier
4185          * there's nothing to be done.
4186          */
4187         if (!ext4_li_info || !ext4_lazyinit_task)
4188                 return;
4189
4190         kthread_stop(ext4_lazyinit_task);
4191 }
4192
4193 static int set_journal_csum_feature_set(struct super_block *sb)
4194 {
4195         int ret = 1;
4196         int compat, incompat;
4197         struct ext4_sb_info *sbi = EXT4_SB(sb);
4198
4199         if (ext4_has_metadata_csum(sb)) {
4200                 /* journal checksum v3 */
4201                 compat = 0;
4202                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4203         } else {
4204                 /* journal checksum v1 */
4205                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4206                 incompat = 0;
4207         }
4208
4209         jbd2_journal_clear_features(sbi->s_journal,
4210                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4211                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4212                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
4213         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4214                 ret = jbd2_journal_set_features(sbi->s_journal,
4215                                 compat, 0,
4216                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4217                                 incompat);
4218         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4219                 ret = jbd2_journal_set_features(sbi->s_journal,
4220                                 compat, 0,
4221                                 incompat);
4222                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4223                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4224         } else {
4225                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4226                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4227         }
4228
4229         return ret;
4230 }
4231
4232 /*
4233  * Note: calculating the overhead so we can be compatible with
4234  * historical BSD practice is quite difficult in the face of
4235  * clusters/bigalloc.  This is because multiple metadata blocks from
4236  * different block group can end up in the same allocation cluster.
4237  * Calculating the exact overhead in the face of clustered allocation
4238  * requires either O(all block bitmaps) in memory or O(number of block
4239  * groups**2) in time.  We will still calculate the superblock for
4240  * older file systems --- and if we come across with a bigalloc file
4241  * system with zero in s_overhead_clusters the estimate will be close to
4242  * correct especially for very large cluster sizes --- but for newer
4243  * file systems, it's better to calculate this figure once at mkfs
4244  * time, and store it in the superblock.  If the superblock value is
4245  * present (even for non-bigalloc file systems), we will use it.
4246  */
4247 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4248                           char *buf)
4249 {
4250         struct ext4_sb_info     *sbi = EXT4_SB(sb);
4251         struct ext4_group_desc  *gdp;
4252         ext4_fsblk_t            first_block, last_block, b;
4253         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
4254         int                     s, j, count = 0;
4255
4256         if (!ext4_has_feature_bigalloc(sb))
4257                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
4258                         sbi->s_itb_per_group + 2);
4259
4260         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4261                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
4262         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4263         for (i = 0; i < ngroups; i++) {
4264                 gdp = ext4_get_group_desc(sb, i, NULL);
4265                 b = ext4_block_bitmap(sb, gdp);
4266                 if (b >= first_block && b <= last_block) {
4267                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4268                         count++;
4269                 }
4270                 b = ext4_inode_bitmap(sb, gdp);
4271                 if (b >= first_block && b <= last_block) {
4272                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4273                         count++;
4274                 }
4275                 b = ext4_inode_table(sb, gdp);
4276                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4277                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4278                                 int c = EXT4_B2C(sbi, b - first_block);
4279                                 ext4_set_bit(c, buf);
4280                                 count++;
4281                         }
4282                 if (i != grp)
4283                         continue;
4284                 s = 0;
4285                 if (ext4_bg_has_super(sb, grp)) {
4286                         ext4_set_bit(s++, buf);
4287                         count++;
4288                 }
4289                 j = ext4_bg_num_gdb(sb, grp);
4290                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4291                         ext4_error(sb, "Invalid number of block group "
4292                                    "descriptor blocks: %d", j);
4293                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4294                 }
4295                 count += j;
4296                 for (; j > 0; j--)
4297                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4298         }
4299         if (!count)
4300                 return 0;
4301         return EXT4_CLUSTERS_PER_GROUP(sb) -
4302                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4303 }
4304
4305 /*
4306  * Compute the overhead and stash it in sbi->s_overhead
4307  */
4308 int ext4_calculate_overhead(struct super_block *sb)
4309 {
4310         struct ext4_sb_info *sbi = EXT4_SB(sb);
4311         struct ext4_super_block *es = sbi->s_es;
4312         struct inode *j_inode;
4313         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4314         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4315         ext4_fsblk_t overhead = 0;
4316         char *buf = (char *) get_zeroed_page(GFP_NOFS);
4317
4318         if (!buf)
4319                 return -ENOMEM;
4320
4321         /*
4322          * Compute the overhead (FS structures).  This is constant
4323          * for a given filesystem unless the number of block groups
4324          * changes so we cache the previous value until it does.
4325          */
4326
4327         /*
4328          * All of the blocks before first_data_block are overhead
4329          */
4330         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4331
4332         /*
4333          * Add the overhead found in each block group
4334          */
4335         for (i = 0; i < ngroups; i++) {
4336                 int blks;
4337
4338                 blks = count_overhead(sb, i, buf);
4339                 overhead += blks;
4340                 if (blks)
4341                         memset(buf, 0, PAGE_SIZE);
4342                 cond_resched();
4343         }
4344
4345         /*
4346          * Add the internal journal blocks whether the journal has been
4347          * loaded or not
4348          */
4349         if (sbi->s_journal && !sbi->s_journal_bdev)
4350                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4351         else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4352                 /* j_inum for internal journal is non-zero */
4353                 j_inode = ext4_get_journal_inode(sb, j_inum);
4354                 if (j_inode) {
4355                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4356                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
4357                         iput(j_inode);
4358                 } else {
4359                         ext4_msg(sb, KERN_ERR, "can't get journal size");
4360                 }
4361         }
4362         sbi->s_overhead = overhead;
4363         smp_wmb();
4364         free_page((unsigned long) buf);
4365         return 0;
4366 }
4367
4368 static void ext4_set_resv_clusters(struct super_block *sb)
4369 {
4370         ext4_fsblk_t resv_clusters;
4371         struct ext4_sb_info *sbi = EXT4_SB(sb);
4372
4373         /*
4374          * There's no need to reserve anything when we aren't using extents.
4375          * The space estimates are exact, there are no unwritten extents,
4376          * hole punching doesn't need new metadata... This is needed especially
4377          * to keep ext2/3 backward compatibility.
4378          */
4379         if (!ext4_has_feature_extents(sb))
4380                 return;
4381         /*
4382          * By default we reserve 2% or 4096 clusters, whichever is smaller.
4383          * This should cover the situations where we can not afford to run
4384          * out of space like for example punch hole, or converting
4385          * unwritten extents in delalloc path. In most cases such
4386          * allocation would require 1, or 2 blocks, higher numbers are
4387          * very rare.
4388          */
4389         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4390                          sbi->s_cluster_bits);
4391
4392         do_div(resv_clusters, 50);
4393         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4394
4395         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4396 }
4397
4398 static const char *ext4_quota_mode(struct super_block *sb)
4399 {
4400 #ifdef CONFIG_QUOTA
4401         if (!ext4_quota_capable(sb))
4402                 return "none";
4403
4404         if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4405                 return "journalled";
4406         else
4407                 return "writeback";
4408 #else
4409         return "disabled";
4410 #endif
4411 }
4412
4413 static void ext4_setup_csum_trigger(struct super_block *sb,
4414                                     enum ext4_journal_trigger_type type,
4415                                     void (*trigger)(
4416                                         struct jbd2_buffer_trigger_type *type,
4417                                         struct buffer_head *bh,
4418                                         void *mapped_data,
4419                                         size_t size))
4420 {
4421         struct ext4_sb_info *sbi = EXT4_SB(sb);
4422
4423         sbi->s_journal_triggers[type].sb = sb;
4424         sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4425 }
4426
4427 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4428 {
4429         if (!sbi)
4430                 return;
4431
4432         kfree(sbi->s_blockgroup_lock);
4433         fs_put_dax(sbi->s_daxdev);
4434         kfree(sbi);
4435 }
4436
4437 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4438 {
4439         struct ext4_sb_info *sbi;
4440
4441         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4442         if (!sbi)
4443                 return NULL;
4444
4445         sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev);
4446
4447         sbi->s_blockgroup_lock =
4448                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4449
4450         if (!sbi->s_blockgroup_lock)
4451                 goto err_out;
4452
4453         sb->s_fs_info = sbi;
4454         sbi->s_sb = sb;
4455         return sbi;
4456 err_out:
4457         fs_put_dax(sbi->s_daxdev);
4458         kfree(sbi);
4459         return NULL;
4460 }
4461
4462 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb,
4463                              int silent)
4464 {
4465         struct buffer_head *bh, **group_desc;
4466         struct ext4_super_block *es = NULL;
4467         struct ext4_sb_info *sbi = EXT4_SB(sb);
4468         struct flex_groups **flex_groups;
4469         ext4_fsblk_t block;
4470         ext4_fsblk_t logical_sb_block;
4471         unsigned long offset = 0;
4472         unsigned long def_mount_opts;
4473         struct inode *root;
4474         int ret = -ENOMEM;
4475         int blocksize, clustersize;
4476         unsigned int db_count;
4477         unsigned int i;
4478         int needs_recovery, has_huge_files;
4479         __u64 blocks_count;
4480         int err = 0;
4481         ext4_group_t first_not_zeroed;
4482         struct ext4_fs_context *ctx = fc->fs_private;
4483
4484         /* Set defaults for the variables that will be set during parsing */
4485         ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4486         ctx->mb_optimize_scan = DEFAULT_MB_OPTIMIZE_SCAN;
4487
4488         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4489         sbi->s_sectors_written_start =
4490                 part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
4491
4492         /* -EINVAL is default */
4493         ret = -EINVAL;
4494         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4495         if (!blocksize) {
4496                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4497                 goto out_fail;
4498         }
4499
4500         /*
4501          * The ext4 superblock will not be buffer aligned for other than 1kB
4502          * block sizes.  We need to calculate the offset from buffer start.
4503          */
4504         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4505                 logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4506                 offset = do_div(logical_sb_block, blocksize);
4507         } else {
4508                 logical_sb_block = sbi->s_sb_block;
4509         }
4510
4511         bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4512         if (IS_ERR(bh)) {
4513                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
4514                 ret = PTR_ERR(bh);
4515                 goto out_fail;
4516         }
4517         /*
4518          * Note: s_es must be initialized as soon as possible because
4519          *       some ext4 macro-instructions depend on its value
4520          */
4521         es = (struct ext4_super_block *) (bh->b_data + offset);
4522         sbi->s_es = es;
4523         sb->s_magic = le16_to_cpu(es->s_magic);
4524         if (sb->s_magic != EXT4_SUPER_MAGIC)
4525                 goto cantfind_ext4;
4526         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4527
4528         /* Warn if metadata_csum and gdt_csum are both set. */
4529         if (ext4_has_feature_metadata_csum(sb) &&
4530             ext4_has_feature_gdt_csum(sb))
4531                 ext4_warning(sb, "metadata_csum and uninit_bg are "
4532                              "redundant flags; please run fsck.");
4533
4534         /* Check for a known checksum algorithm */
4535         if (!ext4_verify_csum_type(sb, es)) {
4536                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4537                          "unknown checksum algorithm.");
4538                 silent = 1;
4539                 goto cantfind_ext4;
4540         }
4541         ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4542                                 ext4_orphan_file_block_trigger);
4543
4544         /* Load the checksum driver */
4545         sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4546         if (IS_ERR(sbi->s_chksum_driver)) {
4547                 ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4548                 ret = PTR_ERR(sbi->s_chksum_driver);
4549                 sbi->s_chksum_driver = NULL;
4550                 goto failed_mount;
4551         }
4552
4553         /* Check superblock checksum */
4554         if (!ext4_superblock_csum_verify(sb, es)) {
4555                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4556                          "invalid superblock checksum.  Run e2fsck?");
4557                 silent = 1;
4558                 ret = -EFSBADCRC;
4559                 goto cantfind_ext4;
4560         }
4561
4562         /* Precompute checksum seed for all metadata */
4563         if (ext4_has_feature_csum_seed(sb))
4564                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4565         else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4566                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4567                                                sizeof(es->s_uuid));
4568
4569         /* Set defaults before we parse the mount options */
4570         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4571         set_opt(sb, INIT_INODE_TABLE);
4572         if (def_mount_opts & EXT4_DEFM_DEBUG)
4573                 set_opt(sb, DEBUG);
4574         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4575                 set_opt(sb, GRPID);
4576         if (def_mount_opts & EXT4_DEFM_UID16)
4577                 set_opt(sb, NO_UID32);
4578         /* xattr user namespace & acls are now defaulted on */
4579         set_opt(sb, XATTR_USER);
4580 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4581         set_opt(sb, POSIX_ACL);
4582 #endif
4583         if (ext4_has_feature_fast_commit(sb))
4584                 set_opt2(sb, JOURNAL_FAST_COMMIT);
4585         /* don't forget to enable journal_csum when metadata_csum is enabled. */
4586         if (ext4_has_metadata_csum(sb))
4587                 set_opt(sb, JOURNAL_CHECKSUM);
4588
4589         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4590                 set_opt(sb, JOURNAL_DATA);
4591         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4592                 set_opt(sb, ORDERED_DATA);
4593         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4594                 set_opt(sb, WRITEBACK_DATA);
4595
4596         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4597                 set_opt(sb, ERRORS_PANIC);
4598         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4599                 set_opt(sb, ERRORS_CONT);
4600         else
4601                 set_opt(sb, ERRORS_RO);
4602         /* block_validity enabled by default; disable with noblock_validity */
4603         set_opt(sb, BLOCK_VALIDITY);
4604         if (def_mount_opts & EXT4_DEFM_DISCARD)
4605                 set_opt(sb, DISCARD);
4606
4607         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4608         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4609         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4610         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4611         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4612
4613         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4614                 set_opt(sb, BARRIER);
4615
4616         /*
4617          * enable delayed allocation by default
4618          * Use -o nodelalloc to turn it off
4619          */
4620         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4621             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4622                 set_opt(sb, DELALLOC);
4623
4624         /*
4625          * set default s_li_wait_mult for lazyinit, for the case there is
4626          * no mount option specified.
4627          */
4628         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4629
4630         if (le32_to_cpu(es->s_log_block_size) >
4631             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4632                 ext4_msg(sb, KERN_ERR,
4633                          "Invalid log block size: %u",
4634                          le32_to_cpu(es->s_log_block_size));
4635                 goto failed_mount;
4636         }
4637         if (le32_to_cpu(es->s_log_cluster_size) >
4638             (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4639                 ext4_msg(sb, KERN_ERR,
4640                          "Invalid log cluster size: %u",
4641                          le32_to_cpu(es->s_log_cluster_size));
4642                 goto failed_mount;
4643         }
4644
4645         blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4646
4647         if (blocksize == PAGE_SIZE)
4648                 set_opt(sb, DIOREAD_NOLOCK);
4649
4650         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4651                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4652                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4653         } else {
4654                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4655                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4656                 if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4657                         ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4658                                  sbi->s_first_ino);
4659                         goto failed_mount;
4660                 }
4661                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4662                     (!is_power_of_2(sbi->s_inode_size)) ||
4663                     (sbi->s_inode_size > blocksize)) {
4664                         ext4_msg(sb, KERN_ERR,
4665                                "unsupported inode size: %d",
4666                                sbi->s_inode_size);
4667                         ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4668                         goto failed_mount;
4669                 }
4670                 /*
4671                  * i_atime_extra is the last extra field available for
4672                  * [acm]times in struct ext4_inode. Checking for that
4673                  * field should suffice to ensure we have extra space
4674                  * for all three.
4675                  */
4676                 if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4677                         sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4678                         sb->s_time_gran = 1;
4679                         sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4680                 } else {
4681                         sb->s_time_gran = NSEC_PER_SEC;
4682                         sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4683                 }
4684                 sb->s_time_min = EXT4_TIMESTAMP_MIN;
4685         }
4686         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4687                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4688                         EXT4_GOOD_OLD_INODE_SIZE;
4689                 if (ext4_has_feature_extra_isize(sb)) {
4690                         unsigned v, max = (sbi->s_inode_size -
4691                                            EXT4_GOOD_OLD_INODE_SIZE);
4692
4693                         v = le16_to_cpu(es->s_want_extra_isize);
4694                         if (v > max) {
4695                                 ext4_msg(sb, KERN_ERR,
4696                                          "bad s_want_extra_isize: %d", v);
4697                                 goto failed_mount;
4698                         }
4699                         if (sbi->s_want_extra_isize < v)
4700                                 sbi->s_want_extra_isize = v;
4701
4702                         v = le16_to_cpu(es->s_min_extra_isize);
4703                         if (v > max) {
4704                                 ext4_msg(sb, KERN_ERR,
4705                                          "bad s_min_extra_isize: %d", v);
4706                                 goto failed_mount;
4707                         }
4708                         if (sbi->s_want_extra_isize < v)
4709                                 sbi->s_want_extra_isize = v;
4710                 }
4711         }
4712
4713         err = parse_apply_sb_mount_options(sb, ctx);
4714         if (err < 0)
4715                 goto failed_mount;
4716
4717         sbi->s_def_mount_opt = sbi->s_mount_opt;
4718
4719         err = ext4_check_opt_consistency(fc, sb);
4720         if (err < 0)
4721                 goto failed_mount;
4722
4723         err = ext4_apply_options(fc, sb);
4724         if (err < 0)
4725                 goto failed_mount;
4726
4727 #ifdef CONFIG_UNICODE
4728         if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4729                 const struct ext4_sb_encodings *encoding_info;
4730                 struct unicode_map *encoding;
4731                 __u16 encoding_flags;
4732
4733                 if (ext4_sb_read_encoding(es, &encoding_info,
4734                                           &encoding_flags)) {
4735                         ext4_msg(sb, KERN_ERR,
4736                                  "Encoding requested by superblock is unknown");
4737                         goto failed_mount;
4738                 }
4739
4740                 encoding = utf8_load(encoding_info->version);
4741                 if (IS_ERR(encoding)) {
4742                         ext4_msg(sb, KERN_ERR,
4743                                  "can't mount with superblock charset: %s-%s "
4744                                  "not supported by the kernel. flags: 0x%x.",
4745                                  encoding_info->name, encoding_info->version,
4746                                  encoding_flags);
4747                         goto failed_mount;
4748                 }
4749                 ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4750                          "%s-%s with flags 0x%hx", encoding_info->name,
4751                          encoding_info->version?:"\b", encoding_flags);
4752
4753                 sb->s_encoding = encoding;
4754                 sb->s_encoding_flags = encoding_flags;
4755         }
4756 #endif
4757
4758         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4759                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4760                 /* can't mount with both data=journal and dioread_nolock. */
4761                 clear_opt(sb, DIOREAD_NOLOCK);
4762                 clear_opt2(sb, JOURNAL_FAST_COMMIT);
4763                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4764                         ext4_msg(sb, KERN_ERR, "can't mount with "
4765                                  "both data=journal and delalloc");
4766                         goto failed_mount;
4767                 }
4768                 if (test_opt(sb, DAX_ALWAYS)) {
4769                         ext4_msg(sb, KERN_ERR, "can't mount with "
4770                                  "both data=journal and dax");
4771                         goto failed_mount;
4772                 }
4773                 if (ext4_has_feature_encrypt(sb)) {
4774                         ext4_msg(sb, KERN_WARNING,
4775                                  "encrypted files will use data=ordered "
4776                                  "instead of data journaling mode");
4777                 }
4778                 if (test_opt(sb, DELALLOC))
4779                         clear_opt(sb, DELALLOC);
4780         } else {
4781                 sb->s_iflags |= SB_I_CGROUPWB;
4782         }
4783
4784         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4785                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4786
4787         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4788             (ext4_has_compat_features(sb) ||
4789              ext4_has_ro_compat_features(sb) ||
4790              ext4_has_incompat_features(sb)))
4791                 ext4_msg(sb, KERN_WARNING,
4792                        "feature flags set on rev 0 fs, "
4793                        "running e2fsck is recommended");
4794
4795         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4796                 set_opt2(sb, HURD_COMPAT);
4797                 if (ext4_has_feature_64bit(sb)) {
4798                         ext4_msg(sb, KERN_ERR,
4799                                  "The Hurd can't support 64-bit file systems");
4800                         goto failed_mount;
4801                 }
4802
4803                 /*
4804                  * ea_inode feature uses l_i_version field which is not
4805                  * available in HURD_COMPAT mode.
4806                  */
4807                 if (ext4_has_feature_ea_inode(sb)) {
4808                         ext4_msg(sb, KERN_ERR,
4809                                  "ea_inode feature is not supported for Hurd");
4810                         goto failed_mount;
4811                 }
4812         }
4813
4814         if (IS_EXT2_SB(sb)) {
4815                 if (ext2_feature_set_ok(sb))
4816                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4817                                  "using the ext4 subsystem");
4818                 else {
4819                         /*
4820                          * If we're probing be silent, if this looks like
4821                          * it's actually an ext[34] filesystem.
4822                          */
4823                         if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4824                                 goto failed_mount;
4825                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4826                                  "to feature incompatibilities");
4827                         goto failed_mount;
4828                 }
4829         }
4830
4831         if (IS_EXT3_SB(sb)) {
4832                 if (ext3_feature_set_ok(sb))
4833                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4834                                  "using the ext4 subsystem");
4835                 else {
4836                         /*
4837                          * If we're probing be silent, if this looks like
4838                          * it's actually an ext4 filesystem.
4839                          */
4840                         if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4841                                 goto failed_mount;
4842                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4843                                  "to feature incompatibilities");
4844                         goto failed_mount;
4845                 }
4846         }
4847
4848         /*
4849          * Check feature flags regardless of the revision level, since we
4850          * previously didn't change the revision level when setting the flags,
4851          * so there is a chance incompat flags are set on a rev 0 filesystem.
4852          */
4853         if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4854                 goto failed_mount;
4855
4856         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4857                 ext4_msg(sb, KERN_ERR,
4858                          "Number of reserved GDT blocks insanely large: %d",
4859                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4860                 goto failed_mount;
4861         }
4862
4863         if (dax_supported(sbi->s_daxdev, sb->s_bdev, blocksize, 0,
4864                         bdev_nr_sectors(sb->s_bdev)))
4865                 set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4866
4867         if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4868                 if (ext4_has_feature_inline_data(sb)) {
4869                         ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4870                                         " that may contain inline data");
4871                         goto failed_mount;
4872                 }
4873                 if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4874                         ext4_msg(sb, KERN_ERR,
4875                                 "DAX unsupported by block device.");
4876                         goto failed_mount;
4877                 }
4878         }
4879
4880         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4881                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4882                          es->s_encryption_level);
4883                 goto failed_mount;
4884         }
4885
4886         if (sb->s_blocksize != blocksize) {
4887                 /*
4888                  * bh must be released before kill_bdev(), otherwise
4889                  * it won't be freed and its page also. kill_bdev()
4890                  * is called by sb_set_blocksize().
4891                  */
4892                 brelse(bh);
4893                 /* Validate the filesystem blocksize */
4894                 if (!sb_set_blocksize(sb, blocksize)) {
4895                         ext4_msg(sb, KERN_ERR, "bad block size %d",
4896                                         blocksize);
4897                         bh = NULL;
4898                         goto failed_mount;
4899                 }
4900
4901                 logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4902                 offset = do_div(logical_sb_block, blocksize);
4903                 bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4904                 if (IS_ERR(bh)) {
4905                         ext4_msg(sb, KERN_ERR,
4906                                "Can't read superblock on 2nd try");
4907                         ret = PTR_ERR(bh);
4908                         bh = NULL;
4909                         goto failed_mount;
4910                 }
4911                 es = (struct ext4_super_block *)(bh->b_data + offset);
4912                 sbi->s_es = es;
4913                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4914                         ext4_msg(sb, KERN_ERR,
4915                                "Magic mismatch, very weird!");
4916                         goto failed_mount;
4917                 }
4918         }
4919
4920         has_huge_files = ext4_has_feature_huge_file(sb);
4921         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4922                                                       has_huge_files);
4923         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4924
4925         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4926         if (ext4_has_feature_64bit(sb)) {
4927                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4928                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4929                     !is_power_of_2(sbi->s_desc_size)) {
4930                         ext4_msg(sb, KERN_ERR,
4931                                "unsupported descriptor size %lu",
4932                                sbi->s_desc_size);
4933                         goto failed_mount;
4934                 }
4935         } else
4936                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4937
4938         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4939         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4940
4941         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4942         if (sbi->s_inodes_per_block == 0)
4943                 goto cantfind_ext4;
4944         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4945             sbi->s_inodes_per_group > blocksize * 8) {
4946                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4947                          sbi->s_inodes_per_group);
4948                 goto failed_mount;
4949         }
4950         sbi->s_itb_per_group = sbi->s_inodes_per_group /
4951                                         sbi->s_inodes_per_block;
4952         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4953         sbi->s_sbh = bh;
4954         sbi->s_mount_state = le16_to_cpu(es->s_state);
4955         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4956         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4957
4958         for (i = 0; i < 4; i++)
4959                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4960         sbi->s_def_hash_version = es->s_def_hash_version;
4961         if (ext4_has_feature_dir_index(sb)) {
4962                 i = le32_to_cpu(es->s_flags);
4963                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
4964                         sbi->s_hash_unsigned = 3;
4965                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4966 #ifdef __CHAR_UNSIGNED__
4967                         if (!sb_rdonly(sb))
4968                                 es->s_flags |=
4969                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4970                         sbi->s_hash_unsigned = 3;
4971 #else
4972                         if (!sb_rdonly(sb))
4973                                 es->s_flags |=
4974                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4975 #endif
4976                 }
4977         }
4978
4979         /* Handle clustersize */
4980         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4981         if (ext4_has_feature_bigalloc(sb)) {
4982                 if (clustersize < blocksize) {
4983                         ext4_msg(sb, KERN_ERR,
4984                                  "cluster size (%d) smaller than "
4985                                  "block size (%d)", clustersize, blocksize);
4986                         goto failed_mount;
4987                 }
4988                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4989                         le32_to_cpu(es->s_log_block_size);
4990                 sbi->s_clusters_per_group =
4991                         le32_to_cpu(es->s_clusters_per_group);
4992                 if (sbi->s_clusters_per_group > blocksize * 8) {
4993                         ext4_msg(sb, KERN_ERR,
4994                                  "#clusters per group too big: %lu",
4995                                  sbi->s_clusters_per_group);
4996                         goto failed_mount;
4997                 }
4998                 if (sbi->s_blocks_per_group !=
4999                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
5000                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
5001                                  "clusters per group (%lu) inconsistent",
5002                                  sbi->s_blocks_per_group,
5003                                  sbi->s_clusters_per_group);
5004                         goto failed_mount;
5005                 }
5006         } else {
5007                 if (clustersize != blocksize) {
5008                         ext4_msg(sb, KERN_ERR,
5009                                  "fragment/cluster size (%d) != "
5010                                  "block size (%d)", clustersize, blocksize);
5011                         goto failed_mount;
5012                 }
5013                 if (sbi->s_blocks_per_group > blocksize * 8) {
5014                         ext4_msg(sb, KERN_ERR,
5015                                  "#blocks per group too big: %lu",
5016                                  sbi->s_blocks_per_group);
5017                         goto failed_mount;
5018                 }
5019                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
5020                 sbi->s_cluster_bits = 0;
5021         }
5022         sbi->s_cluster_ratio = clustersize / blocksize;
5023
5024         /* Do we have standard group size of clustersize * 8 blocks ? */
5025         if (sbi->s_blocks_per_group == clustersize << 3)
5026                 set_opt2(sb, STD_GROUP_SIZE);
5027
5028         /*
5029          * Test whether we have more sectors than will fit in sector_t,
5030          * and whether the max offset is addressable by the page cache.
5031          */
5032         err = generic_check_addressable(sb->s_blocksize_bits,
5033                                         ext4_blocks_count(es));
5034         if (err) {
5035                 ext4_msg(sb, KERN_ERR, "filesystem"
5036                          " too large to mount safely on this system");
5037                 goto failed_mount;
5038         }
5039
5040         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
5041                 goto cantfind_ext4;
5042
5043         /* check blocks count against device size */
5044         blocks_count = sb_bdev_nr_blocks(sb);
5045         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
5046                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
5047                        "exceeds size of device (%llu blocks)",
5048                        ext4_blocks_count(es), blocks_count);
5049                 goto failed_mount;
5050         }
5051
5052         /*
5053          * It makes no sense for the first data block to be beyond the end
5054          * of the filesystem.
5055          */
5056         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
5057                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
5058                          "block %u is beyond end of filesystem (%llu)",
5059                          le32_to_cpu(es->s_first_data_block),
5060                          ext4_blocks_count(es));
5061                 goto failed_mount;
5062         }
5063         if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
5064             (sbi->s_cluster_ratio == 1)) {
5065                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
5066                          "block is 0 with a 1k block and cluster size");
5067                 goto failed_mount;
5068         }
5069
5070         blocks_count = (ext4_blocks_count(es) -
5071                         le32_to_cpu(es->s_first_data_block) +
5072                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
5073         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
5074         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
5075                 ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
5076                        "(block count %llu, first data block %u, "
5077                        "blocks per group %lu)", blocks_count,
5078                        ext4_blocks_count(es),
5079                        le32_to_cpu(es->s_first_data_block),
5080                        EXT4_BLOCKS_PER_GROUP(sb));
5081                 goto failed_mount;
5082         }
5083         sbi->s_groups_count = blocks_count;
5084         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
5085                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
5086         if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
5087             le32_to_cpu(es->s_inodes_count)) {
5088                 ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
5089                          le32_to_cpu(es->s_inodes_count),
5090                          ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
5091                 ret = -EINVAL;
5092                 goto failed_mount;
5093         }
5094         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
5095                    EXT4_DESC_PER_BLOCK(sb);
5096         if (ext4_has_feature_meta_bg(sb)) {
5097                 if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
5098                         ext4_msg(sb, KERN_WARNING,
5099                                  "first meta block group too large: %u "
5100                                  "(group descriptor block count %u)",
5101                                  le32_to_cpu(es->s_first_meta_bg), db_count);
5102                         goto failed_mount;
5103                 }
5104         }
5105         rcu_assign_pointer(sbi->s_group_desc,
5106                            kvmalloc_array(db_count,
5107                                           sizeof(struct buffer_head *),
5108                                           GFP_KERNEL));
5109         if (sbi->s_group_desc == NULL) {
5110                 ext4_msg(sb, KERN_ERR, "not enough memory");
5111                 ret = -ENOMEM;
5112                 goto failed_mount;
5113         }
5114
5115         bgl_lock_init(sbi->s_blockgroup_lock);
5116
5117         /* Pre-read the descriptors into the buffer cache */
5118         for (i = 0; i < db_count; i++) {
5119                 block = descriptor_loc(sb, logical_sb_block, i);
5120                 ext4_sb_breadahead_unmovable(sb, block);
5121         }
5122
5123         for (i = 0; i < db_count; i++) {
5124                 struct buffer_head *bh;
5125
5126                 block = descriptor_loc(sb, logical_sb_block, i);
5127                 bh = ext4_sb_bread_unmovable(sb, block);
5128                 if (IS_ERR(bh)) {
5129                         ext4_msg(sb, KERN_ERR,
5130                                "can't read group descriptor %d", i);
5131                         db_count = i;
5132                         ret = PTR_ERR(bh);
5133                         goto failed_mount2;
5134                 }
5135                 rcu_read_lock();
5136                 rcu_dereference(sbi->s_group_desc)[i] = bh;
5137                 rcu_read_unlock();
5138         }
5139         sbi->s_gdb_count = db_count;
5140         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
5141                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
5142                 ret = -EFSCORRUPTED;
5143                 goto failed_mount2;
5144         }
5145
5146         timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5147         spin_lock_init(&sbi->s_error_lock);
5148         INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
5149
5150         /* Register extent status tree shrinker */
5151         if (ext4_es_register_shrinker(sbi))
5152                 goto failed_mount3;
5153
5154         sbi->s_stripe = ext4_get_stripe_size(sbi);
5155         sbi->s_extent_max_zeroout_kb = 32;
5156
5157         /*
5158          * set up enough so that it can read an inode
5159          */
5160         sb->s_op = &ext4_sops;
5161         sb->s_export_op = &ext4_export_ops;
5162         sb->s_xattr = ext4_xattr_handlers;
5163 #ifdef CONFIG_FS_ENCRYPTION
5164         sb->s_cop = &ext4_cryptops;
5165 #endif
5166 #ifdef CONFIG_FS_VERITY
5167         sb->s_vop = &ext4_verityops;
5168 #endif
5169 #ifdef CONFIG_QUOTA
5170         sb->dq_op = &ext4_quota_operations;
5171         if (ext4_has_feature_quota(sb))
5172                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
5173         else
5174                 sb->s_qcop = &ext4_qctl_operations;
5175         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5176 #endif
5177         memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5178
5179         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5180         mutex_init(&sbi->s_orphan_lock);
5181
5182         /* Initialize fast commit stuff */
5183         atomic_set(&sbi->s_fc_subtid, 0);
5184         atomic_set(&sbi->s_fc_ineligible_updates, 0);
5185         INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
5186         INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
5187         INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
5188         INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
5189         sbi->s_fc_bytes = 0;
5190         ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
5191         ext4_clear_mount_flag(sb, EXT4_MF_FC_COMMITTING);
5192         spin_lock_init(&sbi->s_fc_lock);
5193         memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
5194         sbi->s_fc_replay_state.fc_regions = NULL;
5195         sbi->s_fc_replay_state.fc_regions_size = 0;
5196         sbi->s_fc_replay_state.fc_regions_used = 0;
5197         sbi->s_fc_replay_state.fc_regions_valid = 0;
5198         sbi->s_fc_replay_state.fc_modified_inodes = NULL;
5199         sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
5200         sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
5201
5202         sb->s_root = NULL;
5203
5204         needs_recovery = (es->s_last_orphan != 0 ||
5205                           ext4_has_feature_orphan_present(sb) ||
5206                           ext4_has_feature_journal_needs_recovery(sb));
5207
5208         if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
5209                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
5210                         goto failed_mount3a;
5211
5212         /*
5213          * The first inode we look at is the journal inode.  Don't try
5214          * root first: it may be modified in the journal!
5215          */
5216         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5217                 err = ext4_load_journal(sb, es, ctx->journal_devnum);
5218                 if (err)
5219                         goto failed_mount3a;
5220         } else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5221                    ext4_has_feature_journal_needs_recovery(sb)) {
5222                 ext4_msg(sb, KERN_ERR, "required journal recovery "
5223                        "suppressed and not mounted read-only");
5224                 goto failed_mount_wq;
5225         } else {
5226                 /* Nojournal mode, all journal mount options are illegal */
5227                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5228                         ext4_msg(sb, KERN_ERR, "can't mount with "
5229                                  "journal_checksum, fs mounted w/o journal");
5230                         goto failed_mount_wq;
5231                 }
5232                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5233                         ext4_msg(sb, KERN_ERR, "can't mount with "
5234                                  "journal_async_commit, fs mounted w/o journal");
5235                         goto failed_mount_wq;
5236                 }
5237                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5238                         ext4_msg(sb, KERN_ERR, "can't mount with "
5239                                  "commit=%lu, fs mounted w/o journal",
5240                                  sbi->s_commit_interval / HZ);
5241                         goto failed_mount_wq;
5242                 }
5243                 if (EXT4_MOUNT_DATA_FLAGS &
5244                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5245                         ext4_msg(sb, KERN_ERR, "can't mount with "
5246                                  "data=, fs mounted w/o journal");
5247                         goto failed_mount_wq;
5248                 }
5249                 sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5250                 clear_opt(sb, JOURNAL_CHECKSUM);
5251                 clear_opt(sb, DATA_FLAGS);
5252                 clear_opt2(sb, JOURNAL_FAST_COMMIT);
5253                 sbi->s_journal = NULL;
5254                 needs_recovery = 0;
5255                 goto no_journal;
5256         }
5257
5258         if (ext4_has_feature_64bit(sb) &&
5259             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5260                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
5261                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
5262                 goto failed_mount_wq;
5263         }
5264
5265         if (!set_journal_csum_feature_set(sb)) {
5266                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
5267                          "feature set");
5268                 goto failed_mount_wq;
5269         }
5270
5271         if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
5272                 !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5273                                           JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
5274                 ext4_msg(sb, KERN_ERR,
5275                         "Failed to set fast commit journal feature");
5276                 goto failed_mount_wq;
5277         }
5278
5279         /* We have now updated the journal if required, so we can
5280          * validate the data journaling mode. */
5281         switch (test_opt(sb, DATA_FLAGS)) {
5282         case 0:
5283                 /* No mode set, assume a default based on the journal
5284                  * capabilities: ORDERED_DATA if the journal can
5285                  * cope, else JOURNAL_DATA
5286                  */
5287                 if (jbd2_journal_check_available_features
5288                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5289                         set_opt(sb, ORDERED_DATA);
5290                         sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
5291                 } else {
5292                         set_opt(sb, JOURNAL_DATA);
5293                         sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
5294                 }
5295                 break;
5296
5297         case EXT4_MOUNT_ORDERED_DATA:
5298         case EXT4_MOUNT_WRITEBACK_DATA:
5299                 if (!jbd2_journal_check_available_features
5300                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5301                         ext4_msg(sb, KERN_ERR, "Journal does not support "
5302                                "requested data journaling mode");
5303                         goto failed_mount_wq;
5304                 }
5305                 break;
5306         default:
5307                 break;
5308         }
5309
5310         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
5311             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5312                 ext4_msg(sb, KERN_ERR, "can't mount with "
5313                         "journal_async_commit in data=ordered mode");
5314                 goto failed_mount_wq;
5315         }
5316
5317         set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
5318
5319         sbi->s_journal->j_submit_inode_data_buffers =
5320                 ext4_journal_submit_inode_data_buffers;
5321         sbi->s_journal->j_finish_inode_data_buffers =
5322                 ext4_journal_finish_inode_data_buffers;
5323
5324 no_journal:
5325         if (!test_opt(sb, NO_MBCACHE)) {
5326                 sbi->s_ea_block_cache = ext4_xattr_create_cache();
5327                 if (!sbi->s_ea_block_cache) {
5328                         ext4_msg(sb, KERN_ERR,
5329                                  "Failed to create ea_block_cache");
5330                         goto failed_mount_wq;
5331                 }
5332
5333                 if (ext4_has_feature_ea_inode(sb)) {
5334                         sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5335                         if (!sbi->s_ea_inode_cache) {
5336                                 ext4_msg(sb, KERN_ERR,
5337                                          "Failed to create ea_inode_cache");
5338                                 goto failed_mount_wq;
5339                         }
5340                 }
5341         }
5342
5343         if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
5344                 ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
5345                 goto failed_mount_wq;
5346         }
5347
5348         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
5349             !ext4_has_feature_encrypt(sb)) {
5350                 ext4_set_feature_encrypt(sb);
5351                 ext4_commit_super(sb);
5352         }
5353
5354         /*
5355          * Get the # of file system overhead blocks from the
5356          * superblock if present.
5357          */
5358         if (es->s_overhead_clusters)
5359                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5360         else {
5361                 err = ext4_calculate_overhead(sb);
5362                 if (err)
5363                         goto failed_mount_wq;
5364         }
5365
5366         /*
5367          * The maximum number of concurrent works can be high and
5368          * concurrency isn't really necessary.  Limit it to 1.
5369          */
5370         EXT4_SB(sb)->rsv_conversion_wq =
5371                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5372         if (!EXT4_SB(sb)->rsv_conversion_wq) {
5373                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5374                 ret = -ENOMEM;
5375                 goto failed_mount4;
5376         }
5377
5378         /*
5379          * The jbd2_journal_load will have done any necessary log recovery,
5380          * so we can safely mount the rest of the filesystem now.
5381          */
5382
5383         root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5384         if (IS_ERR(root)) {
5385                 ext4_msg(sb, KERN_ERR, "get root inode failed");
5386                 ret = PTR_ERR(root);
5387                 root = NULL;
5388                 goto failed_mount4;
5389         }
5390         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5391                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5392                 iput(root);
5393                 goto failed_mount4;
5394         }
5395
5396         sb->s_root = d_make_root(root);
5397         if (!sb->s_root) {
5398                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
5399                 ret = -ENOMEM;
5400                 goto failed_mount4;
5401         }
5402
5403         ret = ext4_setup_super(sb, es, sb_rdonly(sb));
5404         if (ret == -EROFS) {
5405                 sb->s_flags |= SB_RDONLY;
5406                 ret = 0;
5407         } else if (ret)
5408                 goto failed_mount4a;
5409
5410         ext4_set_resv_clusters(sb);
5411
5412         if (test_opt(sb, BLOCK_VALIDITY)) {
5413                 err = ext4_setup_system_zone(sb);
5414                 if (err) {
5415                         ext4_msg(sb, KERN_ERR, "failed to initialize system "
5416                                  "zone (%d)", err);
5417                         goto failed_mount4a;
5418                 }
5419         }
5420         ext4_fc_replay_cleanup(sb);
5421
5422         ext4_ext_init(sb);
5423
5424         /*
5425          * Enable optimize_scan if number of groups is > threshold. This can be
5426          * turned off by passing "mb_optimize_scan=0". This can also be
5427          * turned on forcefully by passing "mb_optimize_scan=1".
5428          */
5429         if (ctx->mb_optimize_scan == 1)
5430                 set_opt2(sb, MB_OPTIMIZE_SCAN);
5431         else if (ctx->mb_optimize_scan == 0)
5432                 clear_opt2(sb, MB_OPTIMIZE_SCAN);
5433         else if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5434                 set_opt2(sb, MB_OPTIMIZE_SCAN);
5435
5436         err = ext4_mb_init(sb);
5437         if (err) {
5438                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5439                          err);
5440                 goto failed_mount5;
5441         }
5442
5443         /*
5444          * We can only set up the journal commit callback once
5445          * mballoc is initialized
5446          */
5447         if (sbi->s_journal)
5448                 sbi->s_journal->j_commit_callback =
5449                         ext4_journal_commit_callback;
5450
5451         block = ext4_count_free_clusters(sb);
5452         ext4_free_blocks_count_set(sbi->s_es,
5453                                    EXT4_C2B(sbi, block));
5454         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5455                                   GFP_KERNEL);
5456         if (!err) {
5457                 unsigned long freei = ext4_count_free_inodes(sb);
5458                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5459                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5460                                           GFP_KERNEL);
5461         }
5462         /*
5463          * Update the checksum after updating free space/inode
5464          * counters.  Otherwise the superblock can have an incorrect
5465          * checksum in the buffer cache until it is written out and
5466          * e2fsprogs programs trying to open a file system immediately
5467          * after it is mounted can fail.
5468          */
5469         ext4_superblock_csum_set(sb);
5470         if (!err)
5471                 err = percpu_counter_init(&sbi->s_dirs_counter,
5472                                           ext4_count_dirs(sb), GFP_KERNEL);
5473         if (!err)
5474                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5475                                           GFP_KERNEL);
5476         if (!err)
5477                 err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5478                                           GFP_KERNEL);
5479         if (!err)
5480                 err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5481
5482         if (err) {
5483                 ext4_msg(sb, KERN_ERR, "insufficient memory");
5484                 goto failed_mount6;
5485         }
5486
5487         if (ext4_has_feature_flex_bg(sb))
5488                 if (!ext4_fill_flex_info(sb)) {
5489                         ext4_msg(sb, KERN_ERR,
5490                                "unable to initialize "
5491                                "flex_bg meta info!");
5492                         ret = -ENOMEM;
5493                         goto failed_mount6;
5494                 }
5495
5496         err = ext4_register_li_request(sb, first_not_zeroed);
5497         if (err)
5498                 goto failed_mount6;
5499
5500         err = ext4_register_sysfs(sb);
5501         if (err)
5502                 goto failed_mount7;
5503
5504         err = ext4_init_orphan_info(sb);
5505         if (err)
5506                 goto failed_mount8;
5507 #ifdef CONFIG_QUOTA
5508         /* Enable quota usage during mount. */
5509         if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5510                 err = ext4_enable_quotas(sb);
5511                 if (err)
5512                         goto failed_mount9;
5513         }
5514 #endif  /* CONFIG_QUOTA */
5515
5516         /*
5517          * Save the original bdev mapping's wb_err value which could be
5518          * used to detect the metadata async write error.
5519          */
5520         spin_lock_init(&sbi->s_bdev_wb_lock);
5521         errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5522                                  &sbi->s_bdev_wb_err);
5523         sb->s_bdev->bd_super = sb;
5524         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5525         ext4_orphan_cleanup(sb, es);
5526         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5527         if (needs_recovery) {
5528                 ext4_msg(sb, KERN_INFO, "recovery complete");
5529                 err = ext4_mark_recovery_complete(sb, es);
5530                 if (err)
5531                         goto failed_mount9;
5532         }
5533
5534         if (test_opt(sb, DISCARD)) {
5535                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
5536                 if (!blk_queue_discard(q))
5537                         ext4_msg(sb, KERN_WARNING,
5538                                  "mounting with \"discard\" option, but "
5539                                  "the device does not support discard");
5540         }
5541
5542         if (es->s_error_count)
5543                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5544
5545         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5546         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5547         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5548         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5549         atomic_set(&sbi->s_warning_count, 0);
5550         atomic_set(&sbi->s_msg_count, 0);
5551
5552         return 0;
5553
5554 cantfind_ext4:
5555         if (!silent)
5556                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5557         goto failed_mount;
5558
5559 failed_mount9:
5560         ext4_release_orphan_info(sb);
5561 failed_mount8:
5562         ext4_unregister_sysfs(sb);
5563         kobject_put(&sbi->s_kobj);
5564 failed_mount7:
5565         ext4_unregister_li_request(sb);
5566 failed_mount6:
5567         ext4_mb_release(sb);
5568         rcu_read_lock();
5569         flex_groups = rcu_dereference(sbi->s_flex_groups);
5570         if (flex_groups) {
5571                 for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5572                         kvfree(flex_groups[i]);
5573                 kvfree(flex_groups);
5574         }
5575         rcu_read_unlock();
5576         percpu_counter_destroy(&sbi->s_freeclusters_counter);
5577         percpu_counter_destroy(&sbi->s_freeinodes_counter);
5578         percpu_counter_destroy(&sbi->s_dirs_counter);
5579         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5580         percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5581         percpu_free_rwsem(&sbi->s_writepages_rwsem);
5582 failed_mount5:
5583         ext4_ext_release(sb);
5584         ext4_release_system_zone(sb);
5585 failed_mount4a:
5586         dput(sb->s_root);
5587         sb->s_root = NULL;
5588 failed_mount4:
5589         ext4_msg(sb, KERN_ERR, "mount failed");
5590         if (EXT4_SB(sb)->rsv_conversion_wq)
5591                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5592 failed_mount_wq:
5593         ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5594         sbi->s_ea_inode_cache = NULL;
5595
5596         ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5597         sbi->s_ea_block_cache = NULL;
5598
5599         if (sbi->s_journal) {
5600                 /* flush s_error_work before journal destroy. */
5601                 flush_work(&sbi->s_error_work);
5602                 jbd2_journal_destroy(sbi->s_journal);
5603                 sbi->s_journal = NULL;
5604         }
5605 failed_mount3a:
5606         ext4_es_unregister_shrinker(sbi);
5607 failed_mount3:
5608         /* flush s_error_work before sbi destroy */
5609         flush_work(&sbi->s_error_work);
5610         del_timer_sync(&sbi->s_err_report);
5611         ext4_stop_mmpd(sbi);
5612 failed_mount2:
5613         rcu_read_lock();
5614         group_desc = rcu_dereference(sbi->s_group_desc);
5615         for (i = 0; i < db_count; i++)
5616                 brelse(group_desc[i]);
5617         kvfree(group_desc);
5618         rcu_read_unlock();
5619 failed_mount:
5620         if (sbi->s_chksum_driver)
5621                 crypto_free_shash(sbi->s_chksum_driver);
5622
5623 #ifdef CONFIG_UNICODE
5624         utf8_unload(sb->s_encoding);
5625 #endif
5626
5627 #ifdef CONFIG_QUOTA
5628         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5629                 kfree(get_qf_name(sb, sbi, i));
5630 #endif
5631         fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5632         /* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5633         brelse(bh);
5634         ext4_blkdev_remove(sbi);
5635 out_fail:
5636         sb->s_fs_info = NULL;
5637         return err ? err : ret;
5638 }
5639
5640 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5641 {
5642         struct ext4_fs_context *ctx = fc->fs_private;
5643         struct ext4_sb_info *sbi;
5644         const char *descr;
5645         int ret;
5646
5647         sbi = ext4_alloc_sbi(sb);
5648         if (!sbi)
5649                 ret = -ENOMEM;
5650
5651         fc->s_fs_info = sbi;
5652
5653         /* Cleanup superblock name */
5654         strreplace(sb->s_id, '/', '!');
5655
5656         sbi->s_sb_block = 1;    /* Default super block location */
5657         if (ctx->spec & EXT4_SPEC_s_sb_block)
5658                 sbi->s_sb_block = ctx->s_sb_block;
5659
5660         ret = __ext4_fill_super(fc, sb, fc->sb_flags & SB_SILENT);
5661         if (ret < 0)
5662                 goto free_sbi;
5663
5664         if (sbi->s_journal) {
5665                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5666                         descr = " journalled data mode";
5667                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5668                         descr = " ordered data mode";
5669                 else
5670                         descr = " writeback data mode";
5671         } else
5672                 descr = "out journal";
5673
5674         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5675                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5676                          "Quota mode: %s.", descr, ext4_quota_mode(sb));
5677
5678         return 0;
5679
5680 free_sbi:
5681         ext4_free_sbi(sbi);
5682         fc->s_fs_info = NULL;
5683         return ret;
5684 }
5685
5686 static int ext4_get_tree(struct fs_context *fc)
5687 {
5688         return get_tree_bdev(fc, ext4_fill_super);
5689 }
5690
5691 /*
5692  * Setup any per-fs journal parameters now.  We'll do this both on
5693  * initial mount, once the journal has been initialised but before we've
5694  * done any recovery; and again on any subsequent remount.
5695  */
5696 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5697 {
5698         struct ext4_sb_info *sbi = EXT4_SB(sb);
5699
5700         journal->j_commit_interval = sbi->s_commit_interval;
5701         journal->j_min_batch_time = sbi->s_min_batch_time;
5702         journal->j_max_batch_time = sbi->s_max_batch_time;
5703         ext4_fc_init(sb, journal);
5704
5705         write_lock(&journal->j_state_lock);
5706         if (test_opt(sb, BARRIER))
5707                 journal->j_flags |= JBD2_BARRIER;
5708         else
5709                 journal->j_flags &= ~JBD2_BARRIER;
5710         if (test_opt(sb, DATA_ERR_ABORT))
5711                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5712         else
5713                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5714         write_unlock(&journal->j_state_lock);
5715 }
5716
5717 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5718                                              unsigned int journal_inum)
5719 {
5720         struct inode *journal_inode;
5721
5722         /*
5723          * Test for the existence of a valid inode on disk.  Bad things
5724          * happen if we iget() an unused inode, as the subsequent iput()
5725          * will try to delete it.
5726          */
5727         journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5728         if (IS_ERR(journal_inode)) {
5729                 ext4_msg(sb, KERN_ERR, "no journal found");
5730                 return NULL;
5731         }
5732         if (!journal_inode->i_nlink) {
5733                 make_bad_inode(journal_inode);
5734                 iput(journal_inode);
5735                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5736                 return NULL;
5737         }
5738
5739         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
5740                   journal_inode, journal_inode->i_size);
5741         if (!S_ISREG(journal_inode->i_mode)) {
5742                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
5743                 iput(journal_inode);
5744                 return NULL;
5745         }
5746         return journal_inode;
5747 }
5748
5749 static journal_t *ext4_get_journal(struct super_block *sb,
5750                                    unsigned int journal_inum)
5751 {
5752         struct inode *journal_inode;
5753         journal_t *journal;
5754
5755         if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5756                 return NULL;
5757
5758         journal_inode = ext4_get_journal_inode(sb, journal_inum);
5759         if (!journal_inode)
5760                 return NULL;
5761
5762         journal = jbd2_journal_init_inode(journal_inode);
5763         if (!journal) {
5764                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5765                 iput(journal_inode);
5766                 return NULL;
5767         }
5768         journal->j_private = sb;
5769         ext4_init_journal_params(sb, journal);
5770         return journal;
5771 }
5772
5773 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5774                                        dev_t j_dev)
5775 {
5776         struct buffer_head *bh;
5777         journal_t *journal;
5778         ext4_fsblk_t start;
5779         ext4_fsblk_t len;
5780         int hblock, blocksize;
5781         ext4_fsblk_t sb_block;
5782         unsigned long offset;
5783         struct ext4_super_block *es;
5784         struct block_device *bdev;
5785
5786         if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5787                 return NULL;
5788
5789         bdev = ext4_blkdev_get(j_dev, sb);
5790         if (bdev == NULL)
5791                 return NULL;
5792
5793         blocksize = sb->s_blocksize;
5794         hblock = bdev_logical_block_size(bdev);
5795         if (blocksize < hblock) {
5796                 ext4_msg(sb, KERN_ERR,
5797                         "blocksize too small for journal device");
5798                 goto out_bdev;
5799         }
5800
5801         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5802         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5803         set_blocksize(bdev, blocksize);
5804         if (!(bh = __bread(bdev, sb_block, blocksize))) {
5805                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5806                        "external journal");
5807                 goto out_bdev;
5808         }
5809
5810         es = (struct ext4_super_block *) (bh->b_data + offset);
5811         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5812             !(le32_to_cpu(es->s_feature_incompat) &
5813               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5814                 ext4_msg(sb, KERN_ERR, "external journal has "
5815                                         "bad superblock");
5816                 brelse(bh);
5817                 goto out_bdev;
5818         }
5819
5820         if ((le32_to_cpu(es->s_feature_ro_compat) &
5821              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5822             es->s_checksum != ext4_superblock_csum(sb, es)) {
5823                 ext4_msg(sb, KERN_ERR, "external journal has "
5824                                        "corrupt superblock");
5825                 brelse(bh);
5826                 goto out_bdev;
5827         }
5828
5829         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5830                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5831                 brelse(bh);
5832                 goto out_bdev;
5833         }
5834
5835         len = ext4_blocks_count(es);
5836         start = sb_block + 1;
5837         brelse(bh);     /* we're done with the superblock */
5838
5839         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5840                                         start, len, blocksize);
5841         if (!journal) {
5842                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
5843                 goto out_bdev;
5844         }
5845         journal->j_private = sb;
5846         if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5847                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5848                 goto out_journal;
5849         }
5850         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5851                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
5852                                         "user (unsupported) - %d",
5853                         be32_to_cpu(journal->j_superblock->s_nr_users));
5854                 goto out_journal;
5855         }
5856         EXT4_SB(sb)->s_journal_bdev = bdev;
5857         ext4_init_journal_params(sb, journal);
5858         return journal;
5859
5860 out_journal:
5861         jbd2_journal_destroy(journal);
5862 out_bdev:
5863         ext4_blkdev_put(bdev);
5864         return NULL;
5865 }
5866
5867 static int ext4_load_journal(struct super_block *sb,
5868                              struct ext4_super_block *es,
5869                              unsigned long journal_devnum)
5870 {
5871         journal_t *journal;
5872         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5873         dev_t journal_dev;
5874         int err = 0;
5875         int really_read_only;
5876         int journal_dev_ro;
5877
5878         if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5879                 return -EFSCORRUPTED;
5880
5881         if (journal_devnum &&
5882             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5883                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5884                         "numbers have changed");
5885                 journal_dev = new_decode_dev(journal_devnum);
5886         } else
5887                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5888
5889         if (journal_inum && journal_dev) {
5890                 ext4_msg(sb, KERN_ERR,
5891                          "filesystem has both journal inode and journal device!");
5892                 return -EINVAL;
5893         }
5894
5895         if (journal_inum) {
5896                 journal = ext4_get_journal(sb, journal_inum);
5897                 if (!journal)
5898                         return -EINVAL;
5899         } else {
5900                 journal = ext4_get_dev_journal(sb, journal_dev);
5901                 if (!journal)
5902                         return -EINVAL;
5903         }
5904
5905         journal_dev_ro = bdev_read_only(journal->j_dev);
5906         really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5907
5908         if (journal_dev_ro && !sb_rdonly(sb)) {
5909                 ext4_msg(sb, KERN_ERR,
5910                          "journal device read-only, try mounting with '-o ro'");
5911                 err = -EROFS;
5912                 goto err_out;
5913         }
5914
5915         /*
5916          * Are we loading a blank journal or performing recovery after a
5917          * crash?  For recovery, we need to check in advance whether we
5918          * can get read-write access to the device.
5919          */
5920         if (ext4_has_feature_journal_needs_recovery(sb)) {
5921                 if (sb_rdonly(sb)) {
5922                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
5923                                         "required on readonly filesystem");
5924                         if (really_read_only) {
5925                                 ext4_msg(sb, KERN_ERR, "write access "
5926                                         "unavailable, cannot proceed "
5927                                         "(try mounting with noload)");
5928                                 err = -EROFS;
5929                                 goto err_out;
5930                         }
5931                         ext4_msg(sb, KERN_INFO, "write access will "
5932                                "be enabled during recovery");
5933                 }
5934         }
5935
5936         if (!(journal->j_flags & JBD2_BARRIER))
5937                 ext4_msg(sb, KERN_INFO, "barriers disabled");
5938
5939         if (!ext4_has_feature_journal_needs_recovery(sb))
5940                 err = jbd2_journal_wipe(journal, !really_read_only);
5941         if (!err) {
5942                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5943                 if (save)
5944                         memcpy(save, ((char *) es) +
5945                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5946                 err = jbd2_journal_load(journal);
5947                 if (save)
5948                         memcpy(((char *) es) + EXT4_S_ERR_START,
5949                                save, EXT4_S_ERR_LEN);
5950                 kfree(save);
5951         }
5952
5953         if (err) {
5954                 ext4_msg(sb, KERN_ERR, "error loading journal");
5955                 goto err_out;
5956         }
5957
5958         EXT4_SB(sb)->s_journal = journal;
5959         err = ext4_clear_journal_err(sb, es);
5960         if (err) {
5961                 EXT4_SB(sb)->s_journal = NULL;
5962                 jbd2_journal_destroy(journal);
5963                 return err;
5964         }
5965
5966         if (!really_read_only && journal_devnum &&
5967             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5968                 es->s_journal_dev = cpu_to_le32(journal_devnum);
5969
5970                 /* Make sure we flush the recovery flag to disk. */
5971                 ext4_commit_super(sb);
5972         }
5973
5974         return 0;
5975
5976 err_out:
5977         jbd2_journal_destroy(journal);
5978         return err;
5979 }
5980
5981 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5982 static void ext4_update_super(struct super_block *sb)
5983 {
5984         struct ext4_sb_info *sbi = EXT4_SB(sb);
5985         struct ext4_super_block *es = sbi->s_es;
5986         struct buffer_head *sbh = sbi->s_sbh;
5987
5988         lock_buffer(sbh);
5989         /*
5990          * If the file system is mounted read-only, don't update the
5991          * superblock write time.  This avoids updating the superblock
5992          * write time when we are mounting the root file system
5993          * read/only but we need to replay the journal; at that point,
5994          * for people who are east of GMT and who make their clock
5995          * tick in localtime for Windows bug-for-bug compatibility,
5996          * the clock is set in the future, and this will cause e2fsck
5997          * to complain and force a full file system check.
5998          */
5999         if (!(sb->s_flags & SB_RDONLY))
6000                 ext4_update_tstamp(es, s_wtime);
6001         es->s_kbytes_written =
6002                 cpu_to_le64(sbi->s_kbytes_written +
6003                     ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
6004                       sbi->s_sectors_written_start) >> 1));
6005         if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
6006                 ext4_free_blocks_count_set(es,
6007                         EXT4_C2B(sbi, percpu_counter_sum_positive(
6008                                 &sbi->s_freeclusters_counter)));
6009         if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
6010                 es->s_free_inodes_count =
6011                         cpu_to_le32(percpu_counter_sum_positive(
6012                                 &sbi->s_freeinodes_counter));
6013         /* Copy error information to the on-disk superblock */
6014         spin_lock(&sbi->s_error_lock);
6015         if (sbi->s_add_error_count > 0) {
6016                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6017                 if (!es->s_first_error_time && !es->s_first_error_time_hi) {
6018                         __ext4_update_tstamp(&es->s_first_error_time,
6019                                              &es->s_first_error_time_hi,
6020                                              sbi->s_first_error_time);
6021                         strncpy(es->s_first_error_func, sbi->s_first_error_func,
6022                                 sizeof(es->s_first_error_func));
6023                         es->s_first_error_line =
6024                                 cpu_to_le32(sbi->s_first_error_line);
6025                         es->s_first_error_ino =
6026                                 cpu_to_le32(sbi->s_first_error_ino);
6027                         es->s_first_error_block =
6028                                 cpu_to_le64(sbi->s_first_error_block);
6029                         es->s_first_error_errcode =
6030                                 ext4_errno_to_code(sbi->s_first_error_code);
6031                 }
6032                 __ext4_update_tstamp(&es->s_last_error_time,
6033                                      &es->s_last_error_time_hi,
6034                                      sbi->s_last_error_time);
6035                 strncpy(es->s_last_error_func, sbi->s_last_error_func,
6036                         sizeof(es->s_last_error_func));
6037                 es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
6038                 es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
6039                 es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
6040                 es->s_last_error_errcode =
6041                                 ext4_errno_to_code(sbi->s_last_error_code);
6042                 /*
6043                  * Start the daily error reporting function if it hasn't been
6044                  * started already
6045                  */
6046                 if (!es->s_error_count)
6047                         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
6048                 le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
6049                 sbi->s_add_error_count = 0;
6050         }
6051         spin_unlock(&sbi->s_error_lock);
6052
6053         ext4_superblock_csum_set(sb);
6054         unlock_buffer(sbh);
6055 }
6056
6057 static int ext4_commit_super(struct super_block *sb)
6058 {
6059         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
6060         int error = 0;
6061
6062         if (!sbh)
6063                 return -EINVAL;
6064         if (block_device_ejected(sb))
6065                 return -ENODEV;
6066
6067         ext4_update_super(sb);
6068
6069         if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
6070                 /*
6071                  * Oh, dear.  A previous attempt to write the
6072                  * superblock failed.  This could happen because the
6073                  * USB device was yanked out.  Or it could happen to
6074                  * be a transient write error and maybe the block will
6075                  * be remapped.  Nothing we can do but to retry the
6076                  * write and hope for the best.
6077                  */
6078                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
6079                        "superblock detected");
6080                 clear_buffer_write_io_error(sbh);
6081                 set_buffer_uptodate(sbh);
6082         }
6083         BUFFER_TRACE(sbh, "marking dirty");
6084         mark_buffer_dirty(sbh);
6085         error = __sync_dirty_buffer(sbh,
6086                 REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
6087         if (buffer_write_io_error(sbh)) {
6088                 ext4_msg(sb, KERN_ERR, "I/O error while writing "
6089                        "superblock");
6090                 clear_buffer_write_io_error(sbh);
6091                 set_buffer_uptodate(sbh);
6092         }
6093         return error;
6094 }
6095
6096 /*
6097  * Have we just finished recovery?  If so, and if we are mounting (or
6098  * remounting) the filesystem readonly, then we will end up with a
6099  * consistent fs on disk.  Record that fact.
6100  */
6101 static int ext4_mark_recovery_complete(struct super_block *sb,
6102                                        struct ext4_super_block *es)
6103 {
6104         int err;
6105         journal_t *journal = EXT4_SB(sb)->s_journal;
6106
6107         if (!ext4_has_feature_journal(sb)) {
6108                 if (journal != NULL) {
6109                         ext4_error(sb, "Journal got removed while the fs was "
6110                                    "mounted!");
6111                         return -EFSCORRUPTED;
6112                 }
6113                 return 0;
6114         }
6115         jbd2_journal_lock_updates(journal);
6116         err = jbd2_journal_flush(journal, 0);
6117         if (err < 0)
6118                 goto out;
6119
6120         if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
6121             ext4_has_feature_orphan_present(sb))) {
6122                 if (!ext4_orphan_file_empty(sb)) {
6123                         ext4_error(sb, "Orphan file not empty on read-only fs.");
6124                         err = -EFSCORRUPTED;
6125                         goto out;
6126                 }
6127                 ext4_clear_feature_journal_needs_recovery(sb);
6128                 ext4_clear_feature_orphan_present(sb);
6129                 ext4_commit_super(sb);
6130         }
6131 out:
6132         jbd2_journal_unlock_updates(journal);
6133         return err;
6134 }
6135
6136 /*
6137  * If we are mounting (or read-write remounting) a filesystem whose journal
6138  * has recorded an error from a previous lifetime, move that error to the
6139  * main filesystem now.
6140  */
6141 static int ext4_clear_journal_err(struct super_block *sb,
6142                                    struct ext4_super_block *es)
6143 {
6144         journal_t *journal;
6145         int j_errno;
6146         const char *errstr;
6147
6148         if (!ext4_has_feature_journal(sb)) {
6149                 ext4_error(sb, "Journal got removed while the fs was mounted!");
6150                 return -EFSCORRUPTED;
6151         }
6152
6153         journal = EXT4_SB(sb)->s_journal;
6154
6155         /*
6156          * Now check for any error status which may have been recorded in the
6157          * journal by a prior ext4_error() or ext4_abort()
6158          */
6159
6160         j_errno = jbd2_journal_errno(journal);
6161         if (j_errno) {
6162                 char nbuf[16];
6163
6164                 errstr = ext4_decode_error(sb, j_errno, nbuf);
6165                 ext4_warning(sb, "Filesystem error recorded "
6166                              "from previous mount: %s", errstr);
6167                 ext4_warning(sb, "Marking fs in need of filesystem check.");
6168
6169                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6170                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6171                 ext4_commit_super(sb);
6172
6173                 jbd2_journal_clear_err(journal);
6174                 jbd2_journal_update_sb_errno(journal);
6175         }
6176         return 0;
6177 }
6178
6179 /*
6180  * Force the running and committing transactions to commit,
6181  * and wait on the commit.
6182  */
6183 int ext4_force_commit(struct super_block *sb)
6184 {
6185         journal_t *journal;
6186
6187         if (sb_rdonly(sb))
6188                 return 0;
6189
6190         journal = EXT4_SB(sb)->s_journal;
6191         return ext4_journal_force_commit(journal);
6192 }
6193
6194 static int ext4_sync_fs(struct super_block *sb, int wait)
6195 {
6196         int ret = 0;
6197         tid_t target;
6198         bool needs_barrier = false;
6199         struct ext4_sb_info *sbi = EXT4_SB(sb);
6200
6201         if (unlikely(ext4_forced_shutdown(sbi)))
6202                 return 0;
6203
6204         trace_ext4_sync_fs(sb, wait);
6205         flush_workqueue(sbi->rsv_conversion_wq);
6206         /*
6207          * Writeback quota in non-journalled quota case - journalled quota has
6208          * no dirty dquots
6209          */
6210         dquot_writeback_dquots(sb, -1);
6211         /*
6212          * Data writeback is possible w/o journal transaction, so barrier must
6213          * being sent at the end of the function. But we can skip it if
6214          * transaction_commit will do it for us.
6215          */
6216         if (sbi->s_journal) {
6217                 target = jbd2_get_latest_transaction(sbi->s_journal);
6218                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6219                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6220                         needs_barrier = true;
6221
6222                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6223                         if (wait)
6224                                 ret = jbd2_log_wait_commit(sbi->s_journal,
6225                                                            target);
6226                 }
6227         } else if (wait && test_opt(sb, BARRIER))
6228                 needs_barrier = true;
6229         if (needs_barrier) {
6230                 int err;
6231                 err = blkdev_issue_flush(sb->s_bdev);
6232                 if (!ret)
6233                         ret = err;
6234         }
6235
6236         return ret;
6237 }
6238
6239 /*
6240  * LVM calls this function before a (read-only) snapshot is created.  This
6241  * gives us a chance to flush the journal completely and mark the fs clean.
6242  *
6243  * Note that only this function cannot bring a filesystem to be in a clean
6244  * state independently. It relies on upper layer to stop all data & metadata
6245  * modifications.
6246  */
6247 static int ext4_freeze(struct super_block *sb)
6248 {
6249         int error = 0;
6250         journal_t *journal;
6251
6252         if (sb_rdonly(sb))
6253                 return 0;
6254
6255         journal = EXT4_SB(sb)->s_journal;
6256
6257         if (journal) {
6258                 /* Now we set up the journal barrier. */
6259                 jbd2_journal_lock_updates(journal);
6260
6261                 /*
6262                  * Don't clear the needs_recovery flag if we failed to
6263                  * flush the journal.
6264                  */
6265                 error = jbd2_journal_flush(journal, 0);
6266                 if (error < 0)
6267                         goto out;
6268
6269                 /* Journal blocked and flushed, clear needs_recovery flag. */
6270                 ext4_clear_feature_journal_needs_recovery(sb);
6271                 if (ext4_orphan_file_empty(sb))
6272                         ext4_clear_feature_orphan_present(sb);
6273         }
6274
6275         error = ext4_commit_super(sb);
6276 out:
6277         if (journal)
6278                 /* we rely on upper layer to stop further updates */
6279                 jbd2_journal_unlock_updates(journal);
6280         return error;
6281 }
6282
6283 /*
6284  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6285  * flag here, even though the filesystem is not technically dirty yet.
6286  */
6287 static int ext4_unfreeze(struct super_block *sb)
6288 {
6289         if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6290                 return 0;
6291
6292         if (EXT4_SB(sb)->s_journal) {
6293                 /* Reset the needs_recovery flag before the fs is unlocked. */
6294                 ext4_set_feature_journal_needs_recovery(sb);
6295                 if (ext4_has_feature_orphan_file(sb))
6296                         ext4_set_feature_orphan_present(sb);
6297         }
6298
6299         ext4_commit_super(sb);
6300         return 0;
6301 }
6302
6303 /*
6304  * Structure to save mount options for ext4_remount's benefit
6305  */
6306 struct ext4_mount_options {
6307         unsigned long s_mount_opt;
6308         unsigned long s_mount_opt2;
6309         kuid_t s_resuid;
6310         kgid_t s_resgid;
6311         unsigned long s_commit_interval;
6312         u32 s_min_batch_time, s_max_batch_time;
6313 #ifdef CONFIG_QUOTA
6314         int s_jquota_fmt;
6315         char *s_qf_names[EXT4_MAXQUOTAS];
6316 #endif
6317 };
6318
6319 static int __ext4_remount(struct fs_context *fc, struct super_block *sb,
6320                           int *flags)
6321 {
6322         struct ext4_fs_context *ctx = fc->fs_private;
6323         struct ext4_super_block *es;
6324         struct ext4_sb_info *sbi = EXT4_SB(sb);
6325         unsigned long old_sb_flags, vfs_flags;
6326         struct ext4_mount_options old_opts;
6327         ext4_group_t g;
6328         int err = 0;
6329 #ifdef CONFIG_QUOTA
6330         int enable_quota = 0;
6331         int i, j;
6332         char *to_free[EXT4_MAXQUOTAS];
6333 #endif
6334
6335         ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6336
6337         /* Store the original options */
6338         old_sb_flags = sb->s_flags;
6339         old_opts.s_mount_opt = sbi->s_mount_opt;
6340         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6341         old_opts.s_resuid = sbi->s_resuid;
6342         old_opts.s_resgid = sbi->s_resgid;
6343         old_opts.s_commit_interval = sbi->s_commit_interval;
6344         old_opts.s_min_batch_time = sbi->s_min_batch_time;
6345         old_opts.s_max_batch_time = sbi->s_max_batch_time;
6346 #ifdef CONFIG_QUOTA
6347         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6348         for (i = 0; i < EXT4_MAXQUOTAS; i++)
6349                 if (sbi->s_qf_names[i]) {
6350                         char *qf_name = get_qf_name(sb, sbi, i);
6351
6352                         old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6353                         if (!old_opts.s_qf_names[i]) {
6354                                 for (j = 0; j < i; j++)
6355                                         kfree(old_opts.s_qf_names[j]);
6356                                 return -ENOMEM;
6357                         }
6358                 } else
6359                         old_opts.s_qf_names[i] = NULL;
6360 #endif
6361         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6362                 ctx->journal_ioprio =
6363                         sbi->s_journal->j_task->io_context->ioprio;
6364
6365         /*
6366          * Some options can be enabled by ext4 and/or by VFS mount flag
6367          * either way we need to make sure it matches in both *flags and
6368          * s_flags. Copy those selected flags from *flags to s_flags
6369          */
6370         vfs_flags = SB_LAZYTIME | SB_I_VERSION;
6371         sb->s_flags = (sb->s_flags & ~vfs_flags) | (*flags & vfs_flags);
6372
6373         ext4_apply_options(fc, sb);
6374
6375         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6376             test_opt(sb, JOURNAL_CHECKSUM)) {
6377                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6378                          "during remount not supported; ignoring");
6379                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6380         }
6381
6382         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6383                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6384                         ext4_msg(sb, KERN_ERR, "can't mount with "
6385                                  "both data=journal and delalloc");
6386                         err = -EINVAL;
6387                         goto restore_opts;
6388                 }
6389                 if (test_opt(sb, DIOREAD_NOLOCK)) {
6390                         ext4_msg(sb, KERN_ERR, "can't mount with "
6391                                  "both data=journal and dioread_nolock");
6392                         err = -EINVAL;
6393                         goto restore_opts;
6394                 }
6395         } else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6396                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6397                         ext4_msg(sb, KERN_ERR, "can't mount with "
6398                                 "journal_async_commit in data=ordered mode");
6399                         err = -EINVAL;
6400                         goto restore_opts;
6401                 }
6402         }
6403
6404         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6405                 ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6406                 err = -EINVAL;
6407                 goto restore_opts;
6408         }
6409
6410         if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6411                 ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6412
6413         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6414                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6415
6416         es = sbi->s_es;
6417
6418         if (sbi->s_journal) {
6419                 ext4_init_journal_params(sb, sbi->s_journal);
6420                 set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6421         }
6422
6423         /* Flush outstanding errors before changing fs state */
6424         flush_work(&sbi->s_error_work);
6425
6426         if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
6427                 if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6428                         err = -EROFS;
6429                         goto restore_opts;
6430                 }
6431
6432                 if (*flags & SB_RDONLY) {
6433                         err = sync_filesystem(sb);
6434                         if (err < 0)
6435                                 goto restore_opts;
6436                         err = dquot_suspend(sb, -1);
6437                         if (err < 0)
6438                                 goto restore_opts;
6439
6440                         /*
6441                          * First of all, the unconditional stuff we have to do
6442                          * to disable replay of the journal when we next remount
6443                          */
6444                         sb->s_flags |= SB_RDONLY;
6445
6446                         /*
6447                          * OK, test if we are remounting a valid rw partition
6448                          * readonly, and if so set the rdonly flag and then
6449                          * mark the partition as valid again.
6450                          */
6451                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6452                             (sbi->s_mount_state & EXT4_VALID_FS))
6453                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
6454
6455                         if (sbi->s_journal) {
6456                                 /*
6457                                  * We let remount-ro finish even if marking fs
6458                                  * as clean failed...
6459                                  */
6460                                 ext4_mark_recovery_complete(sb, es);
6461                         }
6462                 } else {
6463                         /* Make sure we can mount this feature set readwrite */
6464                         if (ext4_has_feature_readonly(sb) ||
6465                             !ext4_feature_set_ok(sb, 0)) {
6466                                 err = -EROFS;
6467                                 goto restore_opts;
6468                         }
6469                         /*
6470                          * Make sure the group descriptor checksums
6471                          * are sane.  If they aren't, refuse to remount r/w.
6472                          */
6473                         for (g = 0; g < sbi->s_groups_count; g++) {
6474                                 struct ext4_group_desc *gdp =
6475                                         ext4_get_group_desc(sb, g, NULL);
6476
6477                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6478                                         ext4_msg(sb, KERN_ERR,
6479                "ext4_remount: Checksum for group %u failed (%u!=%u)",
6480                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6481                                                le16_to_cpu(gdp->bg_checksum));
6482                                         err = -EFSBADCRC;
6483                                         goto restore_opts;
6484                                 }
6485                         }
6486
6487                         /*
6488                          * If we have an unprocessed orphan list hanging
6489                          * around from a previously readonly bdev mount,
6490                          * require a full umount/remount for now.
6491                          */
6492                         if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6493                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
6494                                        "remount RDWR because of unprocessed "
6495                                        "orphan inode list.  Please "
6496                                        "umount/remount instead");
6497                                 err = -EINVAL;
6498                                 goto restore_opts;
6499                         }
6500
6501                         /*
6502                          * Mounting a RDONLY partition read-write, so reread
6503                          * and store the current valid flag.  (It may have
6504                          * been changed by e2fsck since we originally mounted
6505                          * the partition.)
6506                          */
6507                         if (sbi->s_journal) {
6508                                 err = ext4_clear_journal_err(sb, es);
6509                                 if (err)
6510                                         goto restore_opts;
6511                         }
6512                         sbi->s_mount_state = le16_to_cpu(es->s_state);
6513
6514                         err = ext4_setup_super(sb, es, 0);
6515                         if (err)
6516                                 goto restore_opts;
6517
6518                         sb->s_flags &= ~SB_RDONLY;
6519                         if (ext4_has_feature_mmp(sb))
6520                                 if (ext4_multi_mount_protect(sb,
6521                                                 le64_to_cpu(es->s_mmp_block))) {
6522                                         err = -EROFS;
6523                                         goto restore_opts;
6524                                 }
6525 #ifdef CONFIG_QUOTA
6526                         enable_quota = 1;
6527 #endif
6528                 }
6529         }
6530
6531         /*
6532          * Reinitialize lazy itable initialization thread based on
6533          * current settings
6534          */
6535         if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6536                 ext4_unregister_li_request(sb);
6537         else {
6538                 ext4_group_t first_not_zeroed;
6539                 first_not_zeroed = ext4_has_uninit_itable(sb);
6540                 ext4_register_li_request(sb, first_not_zeroed);
6541         }
6542
6543         /*
6544          * Handle creation of system zone data early because it can fail.
6545          * Releasing of existing data is done when we are sure remount will
6546          * succeed.
6547          */
6548         if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6549                 err = ext4_setup_system_zone(sb);
6550                 if (err)
6551                         goto restore_opts;
6552         }
6553
6554         if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6555                 err = ext4_commit_super(sb);
6556                 if (err)
6557                         goto restore_opts;
6558         }
6559
6560 #ifdef CONFIG_QUOTA
6561         /* Release old quota file names */
6562         for (i = 0; i < EXT4_MAXQUOTAS; i++)
6563                 kfree(old_opts.s_qf_names[i]);
6564         if (enable_quota) {
6565                 if (sb_any_quota_suspended(sb))
6566                         dquot_resume(sb, -1);
6567                 else if (ext4_has_feature_quota(sb)) {
6568                         err = ext4_enable_quotas(sb);
6569                         if (err)
6570                                 goto restore_opts;
6571                 }
6572         }
6573 #endif
6574         if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6575                 ext4_release_system_zone(sb);
6576
6577         if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6578                 ext4_stop_mmpd(sbi);
6579
6580         /*
6581          * Some options can be enabled by ext4 and/or by VFS mount flag
6582          * either way we need to make sure it matches in both *flags and
6583          * s_flags. Copy those selected flags from s_flags to *flags
6584          */
6585         *flags = (*flags & ~vfs_flags) | (sb->s_flags & vfs_flags);
6586
6587         return 0;
6588
6589 restore_opts:
6590         sb->s_flags = old_sb_flags;
6591         sbi->s_mount_opt = old_opts.s_mount_opt;
6592         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6593         sbi->s_resuid = old_opts.s_resuid;
6594         sbi->s_resgid = old_opts.s_resgid;
6595         sbi->s_commit_interval = old_opts.s_commit_interval;
6596         sbi->s_min_batch_time = old_opts.s_min_batch_time;
6597         sbi->s_max_batch_time = old_opts.s_max_batch_time;
6598         if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6599                 ext4_release_system_zone(sb);
6600 #ifdef CONFIG_QUOTA
6601         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6602         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6603                 to_free[i] = get_qf_name(sb, sbi, i);
6604                 rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6605         }
6606         synchronize_rcu();
6607         for (i = 0; i < EXT4_MAXQUOTAS; i++)
6608                 kfree(to_free[i]);
6609 #endif
6610         if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6611                 ext4_stop_mmpd(sbi);
6612         return err;
6613 }
6614
6615 static int ext4_reconfigure(struct fs_context *fc)
6616 {
6617         struct super_block *sb = fc->root->d_sb;
6618         int flags = fc->sb_flags;
6619         int ret;
6620
6621         fc->s_fs_info = EXT4_SB(sb);
6622
6623         ret = ext4_check_opt_consistency(fc, sb);
6624         if (ret < 0)
6625                 return ret;
6626
6627         ret = __ext4_remount(fc, sb, &flags);
6628         if (ret < 0)
6629                 return ret;
6630
6631         ext4_msg(sb, KERN_INFO, "re-mounted. Quota mode: %s.",
6632                  ext4_quota_mode(sb));
6633
6634         return 0;
6635 }
6636
6637 #ifdef CONFIG_QUOTA
6638 static int ext4_statfs_project(struct super_block *sb,
6639                                kprojid_t projid, struct kstatfs *buf)
6640 {
6641         struct kqid qid;
6642         struct dquot *dquot;
6643         u64 limit;
6644         u64 curblock;
6645
6646         qid = make_kqid_projid(projid);
6647         dquot = dqget(sb, qid);
6648         if (IS_ERR(dquot))
6649                 return PTR_ERR(dquot);
6650         spin_lock(&dquot->dq_dqb_lock);
6651
6652         limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6653                              dquot->dq_dqb.dqb_bhardlimit);
6654         limit >>= sb->s_blocksize_bits;
6655
6656         if (limit && buf->f_blocks > limit) {
6657                 curblock = (dquot->dq_dqb.dqb_curspace +
6658                             dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6659                 buf->f_blocks = limit;
6660                 buf->f_bfree = buf->f_bavail =
6661                         (buf->f_blocks > curblock) ?
6662                          (buf->f_blocks - curblock) : 0;
6663         }
6664
6665         limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6666                              dquot->dq_dqb.dqb_ihardlimit);
6667         if (limit && buf->f_files > limit) {
6668                 buf->f_files = limit;
6669                 buf->f_ffree =
6670                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6671                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6672         }
6673
6674         spin_unlock(&dquot->dq_dqb_lock);
6675         dqput(dquot);
6676         return 0;
6677 }
6678 #endif
6679
6680 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6681 {
6682         struct super_block *sb = dentry->d_sb;
6683         struct ext4_sb_info *sbi = EXT4_SB(sb);
6684         struct ext4_super_block *es = sbi->s_es;
6685         ext4_fsblk_t overhead = 0, resv_blocks;
6686         s64 bfree;
6687         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6688
6689         if (!test_opt(sb, MINIX_DF))
6690                 overhead = sbi->s_overhead;
6691
6692         buf->f_type = EXT4_SUPER_MAGIC;
6693         buf->f_bsize = sb->s_blocksize;
6694         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6695         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6696                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6697         /* prevent underflow in case that few free space is available */
6698         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6699         buf->f_bavail = buf->f_bfree -
6700                         (ext4_r_blocks_count(es) + resv_blocks);
6701         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6702                 buf->f_bavail = 0;
6703         buf->f_files = le32_to_cpu(es->s_inodes_count);
6704         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6705         buf->f_namelen = EXT4_NAME_LEN;
6706         buf->f_fsid = uuid_to_fsid(es->s_uuid);
6707
6708 #ifdef CONFIG_QUOTA
6709         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6710             sb_has_quota_limits_enabled(sb, PRJQUOTA))
6711                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6712 #endif
6713         return 0;
6714 }
6715
6716
6717 #ifdef CONFIG_QUOTA
6718
6719 /*
6720  * Helper functions so that transaction is started before we acquire dqio_sem
6721  * to keep correct lock ordering of transaction > dqio_sem
6722  */
6723 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6724 {
6725         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6726 }
6727
6728 static int ext4_write_dquot(struct dquot *dquot)
6729 {
6730         int ret, err;
6731         handle_t *handle;
6732         struct inode *inode;
6733
6734         inode = dquot_to_inode(dquot);
6735         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6736                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6737         if (IS_ERR(handle))
6738                 return PTR_ERR(handle);
6739         ret = dquot_commit(dquot);
6740         err = ext4_journal_stop(handle);
6741         if (!ret)
6742                 ret = err;
6743         return ret;
6744 }
6745
6746 static int ext4_acquire_dquot(struct dquot *dquot)
6747 {
6748         int ret, err;
6749         handle_t *handle;
6750
6751         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6752                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6753         if (IS_ERR(handle))
6754                 return PTR_ERR(handle);
6755         ret = dquot_acquire(dquot);
6756         err = ext4_journal_stop(handle);
6757         if (!ret)
6758                 ret = err;
6759         return ret;
6760 }
6761
6762 static int ext4_release_dquot(struct dquot *dquot)
6763 {
6764         int ret, err;
6765         handle_t *handle;
6766
6767         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6768                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6769         if (IS_ERR(handle)) {
6770                 /* Release dquot anyway to avoid endless cycle in dqput() */
6771                 dquot_release(dquot);
6772                 return PTR_ERR(handle);
6773         }
6774         ret = dquot_release(dquot);
6775         err = ext4_journal_stop(handle);
6776         if (!ret)
6777                 ret = err;
6778         return ret;
6779 }
6780
6781 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6782 {
6783         struct super_block *sb = dquot->dq_sb;
6784
6785         if (ext4_is_quota_journalled(sb)) {
6786                 dquot_mark_dquot_dirty(dquot);
6787                 return ext4_write_dquot(dquot);
6788         } else {
6789                 return dquot_mark_dquot_dirty(dquot);
6790         }
6791 }
6792
6793 static int ext4_write_info(struct super_block *sb, int type)
6794 {
6795         int ret, err;
6796         handle_t *handle;
6797
6798         /* Data block + inode block */
6799         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6800         if (IS_ERR(handle))
6801                 return PTR_ERR(handle);
6802         ret = dquot_commit_info(sb, type);
6803         err = ext4_journal_stop(handle);
6804         if (!ret)
6805                 ret = err;
6806         return ret;
6807 }
6808
6809 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6810 {
6811         struct ext4_inode_info *ei = EXT4_I(inode);
6812
6813         /* The first argument of lockdep_set_subclass has to be
6814          * *exactly* the same as the argument to init_rwsem() --- in
6815          * this case, in init_once() --- or lockdep gets unhappy
6816          * because the name of the lock is set using the
6817          * stringification of the argument to init_rwsem().
6818          */
6819         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
6820         lockdep_set_subclass(&ei->i_data_sem, subclass);
6821 }
6822
6823 /*
6824  * Standard function to be called on quota_on
6825  */
6826 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6827                          const struct path *path)
6828 {
6829         int err;
6830
6831         if (!test_opt(sb, QUOTA))
6832                 return -EINVAL;
6833
6834         /* Quotafile not on the same filesystem? */
6835         if (path->dentry->d_sb != sb)
6836                 return -EXDEV;
6837
6838         /* Quota already enabled for this file? */
6839         if (IS_NOQUOTA(d_inode(path->dentry)))
6840                 return -EBUSY;
6841
6842         /* Journaling quota? */
6843         if (EXT4_SB(sb)->s_qf_names[type]) {
6844                 /* Quotafile not in fs root? */
6845                 if (path->dentry->d_parent != sb->s_root)
6846                         ext4_msg(sb, KERN_WARNING,
6847                                 "Quota file not on filesystem root. "
6848                                 "Journaled quota will not work");
6849                 sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6850         } else {
6851                 /*
6852                  * Clear the flag just in case mount options changed since
6853                  * last time.
6854                  */
6855                 sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6856         }
6857
6858         /*
6859          * When we journal data on quota file, we have to flush journal to see
6860          * all updates to the file when we bypass pagecache...
6861          */
6862         if (EXT4_SB(sb)->s_journal &&
6863             ext4_should_journal_data(d_inode(path->dentry))) {
6864                 /*
6865                  * We don't need to lock updates but journal_flush() could
6866                  * otherwise be livelocked...
6867                  */
6868                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6869                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6870                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6871                 if (err)
6872                         return err;
6873         }
6874
6875         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6876         err = dquot_quota_on(sb, type, format_id, path);
6877         if (err) {
6878                 lockdep_set_quota_inode(path->dentry->d_inode,
6879                                              I_DATA_SEM_NORMAL);
6880         } else {
6881                 struct inode *inode = d_inode(path->dentry);
6882                 handle_t *handle;
6883
6884                 /*
6885                  * Set inode flags to prevent userspace from messing with quota
6886                  * files. If this fails, we return success anyway since quotas
6887                  * are already enabled and this is not a hard failure.
6888                  */
6889                 inode_lock(inode);
6890                 handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6891                 if (IS_ERR(handle))
6892                         goto unlock_inode;
6893                 EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6894                 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6895                                 S_NOATIME | S_IMMUTABLE);
6896                 err = ext4_mark_inode_dirty(handle, inode);
6897                 ext4_journal_stop(handle);
6898         unlock_inode:
6899                 inode_unlock(inode);
6900         }
6901         return err;
6902 }
6903
6904 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6905                              unsigned int flags)
6906 {
6907         int err;
6908         struct inode *qf_inode;
6909         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6910                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6911                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6912                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6913         };
6914
6915         BUG_ON(!ext4_has_feature_quota(sb));
6916
6917         if (!qf_inums[type])
6918                 return -EPERM;
6919
6920         qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6921         if (IS_ERR(qf_inode)) {
6922                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6923                 return PTR_ERR(qf_inode);
6924         }
6925
6926         /* Don't account quota for quota files to avoid recursion */
6927         qf_inode->i_flags |= S_NOQUOTA;
6928         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6929         err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6930         if (err)
6931                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6932         iput(qf_inode);
6933
6934         return err;
6935 }
6936
6937 /* Enable usage tracking for all quota types. */
6938 int ext4_enable_quotas(struct super_block *sb)
6939 {
6940         int type, err = 0;
6941         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6942                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6943                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6944                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6945         };
6946         bool quota_mopt[EXT4_MAXQUOTAS] = {
6947                 test_opt(sb, USRQUOTA),
6948                 test_opt(sb, GRPQUOTA),
6949                 test_opt(sb, PRJQUOTA),
6950         };
6951
6952         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6953         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6954                 if (qf_inums[type]) {
6955                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6956                                 DQUOT_USAGE_ENABLED |
6957                                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6958                         if (err) {
6959                                 ext4_warning(sb,
6960                                         "Failed to enable quota tracking "
6961                                         "(type=%d, err=%d). Please run "
6962                                         "e2fsck to fix.", type, err);
6963                                 for (type--; type >= 0; type--)
6964                                         dquot_quota_off(sb, type);
6965
6966                                 return err;
6967                         }
6968                 }
6969         }
6970         return 0;
6971 }
6972
6973 static int ext4_quota_off(struct super_block *sb, int type)
6974 {
6975         struct inode *inode = sb_dqopt(sb)->files[type];
6976         handle_t *handle;
6977         int err;
6978
6979         /* Force all delayed allocation blocks to be allocated.
6980          * Caller already holds s_umount sem */
6981         if (test_opt(sb, DELALLOC))
6982                 sync_filesystem(sb);
6983
6984         if (!inode || !igrab(inode))
6985                 goto out;
6986
6987         err = dquot_quota_off(sb, type);
6988         if (err || ext4_has_feature_quota(sb))
6989                 goto out_put;
6990
6991         inode_lock(inode);
6992         /*
6993          * Update modification times of quota files when userspace can
6994          * start looking at them. If we fail, we return success anyway since
6995          * this is not a hard failure and quotas are already disabled.
6996          */
6997         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6998         if (IS_ERR(handle)) {
6999                 err = PTR_ERR(handle);
7000                 goto out_unlock;
7001         }
7002         EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
7003         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
7004         inode->i_mtime = inode->i_ctime = current_time(inode);
7005         err = ext4_mark_inode_dirty(handle, inode);
7006         ext4_journal_stop(handle);
7007 out_unlock:
7008         inode_unlock(inode);
7009 out_put:
7010         lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
7011         iput(inode);
7012         return err;
7013 out:
7014         return dquot_quota_off(sb, type);
7015 }
7016
7017 /* Read data from quotafile - avoid pagecache and such because we cannot afford
7018  * acquiring the locks... As quota files are never truncated and quota code
7019  * itself serializes the operations (and no one else should touch the files)
7020  * we don't have to be afraid of races */
7021 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
7022                                size_t len, loff_t off)
7023 {
7024         struct inode *inode = sb_dqopt(sb)->files[type];
7025         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7026         int offset = off & (sb->s_blocksize - 1);
7027         int tocopy;
7028         size_t toread;
7029         struct buffer_head *bh;
7030         loff_t i_size = i_size_read(inode);
7031
7032         if (off > i_size)
7033                 return 0;
7034         if (off+len > i_size)
7035                 len = i_size-off;
7036         toread = len;
7037         while (toread > 0) {
7038                 tocopy = sb->s_blocksize - offset < toread ?
7039                                 sb->s_blocksize - offset : toread;
7040                 bh = ext4_bread(NULL, inode, blk, 0);
7041                 if (IS_ERR(bh))
7042                         return PTR_ERR(bh);
7043                 if (!bh)        /* A hole? */
7044                         memset(data, 0, tocopy);
7045                 else
7046                         memcpy(data, bh->b_data+offset, tocopy);
7047                 brelse(bh);
7048                 offset = 0;
7049                 toread -= tocopy;
7050                 data += tocopy;
7051                 blk++;
7052         }
7053         return len;
7054 }
7055
7056 /* Write to quotafile (we know the transaction is already started and has
7057  * enough credits) */
7058 static ssize_t ext4_quota_write(struct super_block *sb, int type,
7059                                 const char *data, size_t len, loff_t off)
7060 {
7061         struct inode *inode = sb_dqopt(sb)->files[type];
7062         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
7063         int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
7064         int retries = 0;
7065         struct buffer_head *bh;
7066         handle_t *handle = journal_current_handle();
7067
7068         if (EXT4_SB(sb)->s_journal && !handle) {
7069                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7070                         " cancelled because transaction is not started",
7071                         (unsigned long long)off, (unsigned long long)len);
7072                 return -EIO;
7073         }
7074         /*
7075          * Since we account only one data block in transaction credits,
7076          * then it is impossible to cross a block boundary.
7077          */
7078         if (sb->s_blocksize - offset < len) {
7079                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
7080                         " cancelled because not block aligned",
7081                         (unsigned long long)off, (unsigned long long)len);
7082                 return -EIO;
7083         }
7084
7085         do {
7086                 bh = ext4_bread(handle, inode, blk,
7087                                 EXT4_GET_BLOCKS_CREATE |
7088                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
7089         } while (PTR_ERR(bh) == -ENOSPC &&
7090                  ext4_should_retry_alloc(inode->i_sb, &retries));
7091         if (IS_ERR(bh))
7092                 return PTR_ERR(bh);
7093         if (!bh)
7094                 goto out;
7095         BUFFER_TRACE(bh, "get write access");
7096         err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
7097         if (err) {
7098                 brelse(bh);
7099                 return err;
7100         }
7101         lock_buffer(bh);
7102         memcpy(bh->b_data+offset, data, len);
7103         flush_dcache_page(bh->b_page);
7104         unlock_buffer(bh);
7105         err = ext4_handle_dirty_metadata(handle, NULL, bh);
7106         brelse(bh);
7107 out:
7108         if (inode->i_size < off + len) {
7109                 i_size_write(inode, off + len);
7110                 EXT4_I(inode)->i_disksize = inode->i_size;
7111                 err2 = ext4_mark_inode_dirty(handle, inode);
7112                 if (unlikely(err2 && !err))
7113                         err = err2;
7114         }
7115         return err ? err : len;
7116 }
7117 #endif
7118
7119 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
7120 static inline void register_as_ext2(void)
7121 {
7122         int err = register_filesystem(&ext2_fs_type);
7123         if (err)
7124                 printk(KERN_WARNING
7125                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
7126 }
7127
7128 static inline void unregister_as_ext2(void)
7129 {
7130         unregister_filesystem(&ext2_fs_type);
7131 }
7132
7133 static inline int ext2_feature_set_ok(struct super_block *sb)
7134 {
7135         if (ext4_has_unknown_ext2_incompat_features(sb))
7136                 return 0;
7137         if (sb_rdonly(sb))
7138                 return 1;
7139         if (ext4_has_unknown_ext2_ro_compat_features(sb))
7140                 return 0;
7141         return 1;
7142 }
7143 #else
7144 static inline void register_as_ext2(void) { }
7145 static inline void unregister_as_ext2(void) { }
7146 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7147 #endif
7148
7149 static inline void register_as_ext3(void)
7150 {
7151         int err = register_filesystem(&ext3_fs_type);
7152         if (err)
7153                 printk(KERN_WARNING
7154                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7155 }
7156
7157 static inline void unregister_as_ext3(void)
7158 {
7159         unregister_filesystem(&ext3_fs_type);
7160 }
7161
7162 static inline int ext3_feature_set_ok(struct super_block *sb)
7163 {
7164         if (ext4_has_unknown_ext3_incompat_features(sb))
7165                 return 0;
7166         if (!ext4_has_feature_journal(sb))
7167                 return 0;
7168         if (sb_rdonly(sb))
7169                 return 1;
7170         if (ext4_has_unknown_ext3_ro_compat_features(sb))
7171                 return 0;
7172         return 1;
7173 }
7174
7175 static struct file_system_type ext4_fs_type = {
7176         .owner                  = THIS_MODULE,
7177         .name                   = "ext4",
7178         .init_fs_context        = ext4_init_fs_context,
7179         .parameters             = ext4_param_specs,
7180         .kill_sb                = kill_block_super,
7181         .fs_flags               = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7182 };
7183 MODULE_ALIAS_FS("ext4");
7184
7185 /* Shared across all ext4 file systems */
7186 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7187
7188 static int __init ext4_init_fs(void)
7189 {
7190         int i, err;
7191
7192         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7193         ext4_li_info = NULL;
7194
7195         /* Build-time check for flags consistency */
7196         ext4_check_flag_values();
7197
7198         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7199                 init_waitqueue_head(&ext4__ioend_wq[i]);
7200
7201         err = ext4_init_es();
7202         if (err)
7203                 return err;
7204
7205         err = ext4_init_pending();
7206         if (err)
7207                 goto out7;
7208
7209         err = ext4_init_post_read_processing();
7210         if (err)
7211                 goto out6;
7212
7213         err = ext4_init_pageio();
7214         if (err)
7215                 goto out5;
7216
7217         err = ext4_init_system_zone();
7218         if (err)
7219                 goto out4;
7220
7221         err = ext4_init_sysfs();
7222         if (err)
7223                 goto out3;
7224
7225         err = ext4_init_mballoc();
7226         if (err)
7227                 goto out2;
7228         err = init_inodecache();
7229         if (err)
7230                 goto out1;
7231
7232         err = ext4_fc_init_dentry_cache();
7233         if (err)
7234                 goto out05;
7235
7236         register_as_ext3();
7237         register_as_ext2();
7238         err = register_filesystem(&ext4_fs_type);
7239         if (err)
7240                 goto out;
7241
7242         return 0;
7243 out:
7244         unregister_as_ext2();
7245         unregister_as_ext3();
7246 out05:
7247         destroy_inodecache();
7248 out1:
7249         ext4_exit_mballoc();
7250 out2:
7251         ext4_exit_sysfs();
7252 out3:
7253         ext4_exit_system_zone();
7254 out4:
7255         ext4_exit_pageio();
7256 out5:
7257         ext4_exit_post_read_processing();
7258 out6:
7259         ext4_exit_pending();
7260 out7:
7261         ext4_exit_es();
7262
7263         return err;
7264 }
7265
7266 static void __exit ext4_exit_fs(void)
7267 {
7268         ext4_destroy_lazyinit_thread();
7269         unregister_as_ext2();
7270         unregister_as_ext3();
7271         unregister_filesystem(&ext4_fs_type);
7272         destroy_inodecache();
7273         ext4_exit_mballoc();
7274         ext4_exit_sysfs();
7275         ext4_exit_system_zone();
7276         ext4_exit_pageio();
7277         ext4_exit_post_read_processing();
7278         ext4_exit_es();
7279         ext4_exit_pending();
7280 }
7281
7282 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7283 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7284 MODULE_LICENSE("GPL");
7285 MODULE_SOFTDEP("pre: crc32c");
7286 module_init(ext4_init_fs)
7287 module_exit(ext4_exit_fs)