fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/backing-dev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/ctype.h>
  38 #include <linux/log2.h>
  39 #include <linux/crc16.h>
  40 #include <linux/cleancache.h>
  41 #include <linux/uaccess.h>
  42
  43 #include <linux/kthread.h>
  44 #include <linux/freezer.h>
  45
  46 #include "ext4.h"
  47 #include "ext4_extents.h"       /* Needed for trace points definition */
  48 #include "ext4_jbd2.h"
  49 #include "xattr.h"
  50 #include "acl.h"
  51 #include "mballoc.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/ext4.h>
  55
  56 static struct ext4_lazy_init *ext4_li_info;
  57 static struct mutex ext4_li_mtx;
  58 static struct ratelimit_state ext4_mount_msg_ratelimit;
  59
  60 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  61                              unsigned long journal_devnum);
  62 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  63 static int ext4_commit_super(struct super_block *sb, int sync);
  64 static void ext4_mark_recovery_complete(struct super_block *sb,
  65                                         struct ext4_super_block *es);
  66 static void ext4_clear_journal_err(struct super_block *sb,
  67                                    struct ext4_super_block *es);
  68 static int ext4_sync_fs(struct super_block *sb, int wait);
  69 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  70 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  71 static int ext4_unfreeze(struct super_block *sb);
  72 static int ext4_freeze(struct super_block *sb);
  73 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  74                        const char *dev_name, void *data);
  75 static inline int ext2_feature_set_ok(struct super_block *sb);
  76 static inline int ext3_feature_set_ok(struct super_block *sb);
  77 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  78 static void ext4_destroy_lazyinit_thread(void);
  79 static void ext4_unregister_li_request(struct super_block *sb);
  80 static void ext4_clear_request_list(void);
  81 static struct inode *ext4_get_journal_inode(struct super_block *sb,
  82                                             unsigned int journal_inum);
  83
  84 /*
  85  * Lock ordering
  86  *
  87  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  88  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  89  *
  90  * page fault path:
  91  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  92  *   page lock -> i_data_sem (rw)
  93  *
  94  * buffered write path:
  95  * sb_start_write -> i_mutex -> mmap_sem
  96  * sb_start_write -> i_mutex -> transaction start -> page lock ->
  97  *   i_data_sem (rw)
  98  *
  99  * truncate:
 100  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 101  *   i_mmap_rwsem (w) -> page lock
 102  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 103  *   transaction start -> i_data_sem (rw)
 104  *
 105  * direct IO:
 106  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
 107  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
 108  *   transaction start -> i_data_sem (rw)
 109  *
 110  * writepages:
 111  * transaction start -> page lock(s) -> i_data_sem (rw)
 112  */
 113
 114 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 115 static struct file_system_type ext2_fs_type = {
 116         .owner          = THIS_MODULE,
 117         .name           = "ext2",
 118         .mount          = ext4_mount,
 119         .kill_sb        = kill_block_super,
 120         .fs_flags       = FS_REQUIRES_DEV,
 121 };
 122 MODULE_ALIAS_FS("ext2");
 123 MODULE_ALIAS("ext2");
 124 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 125 #else
 126 #define IS_EXT2_SB(sb) (0)
 127 #endif
 128
 129
 130 static struct file_system_type ext3_fs_type = {
 131         .owner          = THIS_MODULE,
 132         .name           = "ext3",
 133         .mount          = ext4_mount,
 134         .kill_sb        = kill_block_super,
 135         .fs_flags       = FS_REQUIRES_DEV,
 136 };
 137 MODULE_ALIAS_FS("ext3");
 138 MODULE_ALIAS("ext3");
 139 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 140
 141 static int ext4_verify_csum_type(struct super_block *sb,
 142                                  struct ext4_super_block *es)
 143 {
 144         if (!ext4_has_feature_metadata_csum(sb))
 145                 return 1;
 146
 147         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 148 }
 149
 150 static __le32 ext4_superblock_csum(struct super_block *sb,
 151                                    struct ext4_super_block *es)
 152 {
 153         struct ext4_sb_info *sbi = EXT4_SB(sb);
 154         int offset = offsetof(struct ext4_super_block, s_checksum);
 155         __u32 csum;
 156
 157         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 158
 159         return cpu_to_le32(csum);
 160 }
 161
 162 static int ext4_superblock_csum_verify(struct super_block *sb,
 163                                        struct ext4_super_block *es)
 164 {
 165         if (!ext4_has_metadata_csum(sb))
 166                 return 1;
 167
 168         return es->s_checksum == ext4_superblock_csum(sb, es);
 169 }
 170
 171 void ext4_superblock_csum_set(struct super_block *sb)
 172 {
 173         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 174
 175         if (!ext4_has_metadata_csum(sb))
 176                 return;
 177
 178         es->s_checksum = ext4_superblock_csum(sb, es);
 179 }
 180
 181 void *ext4_kvmalloc(size_t size, gfp_t flags)
 182 {
 183         void *ret;
 184
 185         ret = kmalloc(size, flags | __GFP_NOWARN);
 186         if (!ret)
 187                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 188         return ret;
 189 }
 190
 191 void *ext4_kvzalloc(size_t size, gfp_t flags)
 192 {
 193         void *ret;
 194
 195         ret = kzalloc(size, flags | __GFP_NOWARN);
 196         if (!ret)
 197                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 198         return ret;
 199 }
 200
 201 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 202                                struct ext4_group_desc *bg)
 203 {
 204         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 205                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 206                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 207 }
 208
 209 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 210                                struct ext4_group_desc *bg)
 211 {
 212         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 213                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 214                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 215 }
 216
 217 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 218                               struct ext4_group_desc *bg)
 219 {
 220         return le32_to_cpu(bg->bg_inode_table_lo) |
 221                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 222                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 223 }
 224
 225 __u32 ext4_free_group_clusters(struct super_block *sb,
 226                                struct ext4_group_desc *bg)
 227 {
 228         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 229                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 230                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 231 }
 232
 233 __u32 ext4_free_inodes_count(struct super_block *sb,
 234                               struct ext4_group_desc *bg)
 235 {
 236         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 237                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 238                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 239 }
 240
 241 __u32 ext4_used_dirs_count(struct super_block *sb,
 242                               struct ext4_group_desc *bg)
 243 {
 244         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 245                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 246                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 247 }
 248
 249 __u32 ext4_itable_unused_count(struct super_block *sb,
 250                               struct ext4_group_desc *bg)
 251 {
 252         return le16_to_cpu(bg->bg_itable_unused_lo) |
 253                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 254                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 255 }
 256
 257 void ext4_block_bitmap_set(struct super_block *sb,
 258                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 259 {
 260         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 261         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 262                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 263 }
 264
 265 void ext4_inode_bitmap_set(struct super_block *sb,
 266                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 267 {
 268         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 269         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 270                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 271 }
 272
 273 void ext4_inode_table_set(struct super_block *sb,
 274                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 275 {
 276         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 277         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 278                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 279 }
 280
 281 void ext4_free_group_clusters_set(struct super_block *sb,
 282                                   struct ext4_group_desc *bg, __u32 count)
 283 {
 284         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 285         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 286                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 287 }
 288
 289 void ext4_free_inodes_set(struct super_block *sb,
 290                           struct ext4_group_desc *bg, __u32 count)
 291 {
 292         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 293         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 294                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 295 }
 296
 297 void ext4_used_dirs_set(struct super_block *sb,
 298                           struct ext4_group_desc *bg, __u32 count)
 299 {
 300         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 301         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 302                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 303 }
 304
 305 void ext4_itable_unused_set(struct super_block *sb,
 306                           struct ext4_group_desc *bg, __u32 count)
 307 {
 308         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 309         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 310                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 311 }
 312
 313
 314 static void __save_error_info(struct super_block *sb, const char *func,
 315                             unsigned int line)
 316 {
 317         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 318
 319         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 320         if (bdev_read_only(sb->s_bdev))
 321                 return;
 322         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 323         es->s_last_error_time = cpu_to_le32(get_seconds());
 324         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 325         es->s_last_error_line = cpu_to_le32(line);
 326         if (!es->s_first_error_time) {
 327                 es->s_first_error_time = es->s_last_error_time;
 328                 strncpy(es->s_first_error_func, func,
 329                         sizeof(es->s_first_error_func));
 330                 es->s_first_error_line = cpu_to_le32(line);
 331                 es->s_first_error_ino = es->s_last_error_ino;
 332                 es->s_first_error_block = es->s_last_error_block;
 333         }
 334         /*
 335          * Start the daily error reporting function if it hasn't been
 336          * started already
 337          */
 338         if (!es->s_error_count)
 339                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 340         le32_add_cpu(&es->s_error_count, 1);
 341 }
 342
 343 static void save_error_info(struct super_block *sb, const char *func,
 344                             unsigned int line)
 345 {
 346         __save_error_info(sb, func, line);
 347         ext4_commit_super(sb, 1);
 348 }
 349
 350 /*
 351  * The del_gendisk() function uninitializes the disk-specific data
 352  * structures, including the bdi structure, without telling anyone
 353  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 354  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 355  * This is a kludge to prevent these oops until we can put in a proper
 356  * hook in del_gendisk() to inform the VFS and file system layers.
 357  */
 358 static int block_device_ejected(struct super_block *sb)
 359 {
 360         struct inode *bd_inode = sb->s_bdev->bd_inode;
 361         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 362
 363         return bdi->dev == NULL;
 364 }
 365
 366 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 367 {
 368         struct super_block              *sb = journal->j_private;
 369         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 370         int                             error = is_journal_aborted(journal);
 371         struct ext4_journal_cb_entry    *jce;
 372
 373         BUG_ON(txn->t_state == T_FINISHED);
 374         spin_lock(&sbi->s_md_lock);
 375         while (!list_empty(&txn->t_private_list)) {
 376                 jce = list_entry(txn->t_private_list.next,
 377                                  struct ext4_journal_cb_entry, jce_list);
 378                 list_del_init(&jce->jce_list);
 379                 spin_unlock(&sbi->s_md_lock);
 380                 jce->jce_func(sb, jce, error);
 381                 spin_lock(&sbi->s_md_lock);
 382         }
 383         spin_unlock(&sbi->s_md_lock);
 384 }
 385
 386 /* Deal with the reporting of failure conditions on a filesystem such as
 387  * inconsistencies detected or read IO failures.
 388  *
 389  * On ext2, we can store the error state of the filesystem in the
 390  * superblock.  That is not possible on ext4, because we may have other
 391  * write ordering constraints on the superblock which prevent us from
 392  * writing it out straight away; and given that the journal is about to
 393  * be aborted, we can't rely on the current, or future, transactions to
 394  * write out the superblock safely.
 395  *
 396  * We'll just use the jbd2_journal_abort() error code to record an error in
 397  * the journal instead.  On recovery, the journal will complain about
 398  * that error until we've noted it down and cleared it.
 399  */
 400
 401 static void ext4_handle_error(struct super_block *sb)
 402 {
 403         if (sb->s_flags & MS_RDONLY)
 404                 return;
 405
 406         if (!test_opt(sb, ERRORS_CONT)) {
 407                 journal_t *journal = EXT4_SB(sb)->s_journal;
 408
 409                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 410                 if (journal)
 411                         jbd2_journal_abort(journal, -EIO);
 412         }
 413         if (test_opt(sb, ERRORS_RO)) {
 414                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 415                 /*
 416                  * Make sure updated value of ->s_mount_flags will be visible
 417                  * before ->s_flags update
 418                  */
 419                 smp_wmb();
 420                 sb->s_flags |= MS_RDONLY;
 421         }
 422         if (test_opt(sb, ERRORS_PANIC)) {
 423                 if (EXT4_SB(sb)->s_journal &&
 424                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 425                         return;
 426                 panic("EXT4-fs (device %s): panic forced after error\n",
 427                         sb->s_id);
 428         }
 429 }
 430
 431 #define ext4_error_ratelimit(sb)                                        \
 432                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 433                              "EXT4-fs error")
 434
 435 void __ext4_error(struct super_block *sb, const char *function,
 436                   unsigned int line, const char *fmt, ...)
 437 {
 438         struct va_format vaf;
 439         va_list args;
 440
 441         if (ext4_error_ratelimit(sb)) {
 442                 va_start(args, fmt);
 443                 vaf.fmt = fmt;
 444                 vaf.va = &args;
 445                 printk(KERN_CRIT
 446                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 447                        sb->s_id, function, line, current->comm, &vaf);
 448                 va_end(args);
 449         }
 450         save_error_info(sb, function, line);
 451         ext4_handle_error(sb);
 452 }
 453
 454 void __ext4_error_inode(struct inode *inode, const char *function,
 455                         unsigned int line, ext4_fsblk_t block,
 456                         const char *fmt, ...)
 457 {
 458         va_list args;
 459         struct va_format vaf;
 460         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 461
 462         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 463         es->s_last_error_block = cpu_to_le64(block);
 464         if (ext4_error_ratelimit(inode->i_sb)) {
 465                 va_start(args, fmt);
 466                 vaf.fmt = fmt;
 467                 vaf.va = &args;
 468                 if (block)
 469                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 470                                "inode #%lu: block %llu: comm %s: %pV\n",
 471                                inode->i_sb->s_id, function, line, inode->i_ino,
 472                                block, current->comm, &vaf);
 473                 else
 474                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 475                                "inode #%lu: comm %s: %pV\n",
 476                                inode->i_sb->s_id, function, line, inode->i_ino,
 477                                current->comm, &vaf);
 478                 va_end(args);
 479         }
 480         save_error_info(inode->i_sb, function, line);
 481         ext4_handle_error(inode->i_sb);
 482 }
 483
 484 void __ext4_error_file(struct file *file, const char *function,
 485                        unsigned int line, ext4_fsblk_t block,
 486                        const char *fmt, ...)
 487 {
 488         va_list args;
 489         struct va_format vaf;
 490         struct ext4_super_block *es;
 491         struct inode *inode = file_inode(file);
 492         char pathname[80], *path;
 493
 494         es = EXT4_SB(inode->i_sb)->s_es;
 495         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 496         if (ext4_error_ratelimit(inode->i_sb)) {
 497                 path = file_path(file, pathname, sizeof(pathname));
 498                 if (IS_ERR(path))
 499                         path = "(unknown)";
 500                 va_start(args, fmt);
 501                 vaf.fmt = fmt;
 502                 vaf.va = &args;
 503                 if (block)
 504                         printk(KERN_CRIT
 505                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 506                                "block %llu: comm %s: path %s: %pV\n",
 507                                inode->i_sb->s_id, function, line, inode->i_ino,
 508                                block, current->comm, path, &vaf);
 509                 else
 510                         printk(KERN_CRIT
 511                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 512                                "comm %s: path %s: %pV\n",
 513                                inode->i_sb->s_id, function, line, inode->i_ino,
 514                                current->comm, path, &vaf);
 515                 va_end(args);
 516         }
 517         save_error_info(inode->i_sb, function, line);
 518         ext4_handle_error(inode->i_sb);
 519 }
 520
 521 const char *ext4_decode_error(struct super_block *sb, int errno,
 522                               char nbuf[16])
 523 {
 524         char *errstr = NULL;
 525
 526         switch (errno) {
 527         case -EFSCORRUPTED:
 528                 errstr = "Corrupt filesystem";
 529                 break;
 530         case -EFSBADCRC:
 531                 errstr = "Filesystem failed CRC";
 532                 break;
 533         case -EIO:
 534                 errstr = "IO failure";
 535                 break;
 536         case -ENOMEM:
 537                 errstr = "Out of memory";
 538                 break;
 539         case -EROFS:
 540                 if (!sb || (EXT4_SB(sb)->s_journal &&
 541                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 542                         errstr = "Journal has aborted";
 543                 else
 544                         errstr = "Readonly filesystem";
 545                 break;
 546         default:
 547                 /* If the caller passed in an extra buffer for unknown
 548                  * errors, textualise them now.  Else we just return
 549                  * NULL. */
 550                 if (nbuf) {
 551                         /* Check for truncated error codes... */
 552                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 553                                 errstr = nbuf;
 554                 }
 555                 break;
 556         }
 557
 558         return errstr;
 559 }
 560
 561 /* __ext4_std_error decodes expected errors from journaling functions
 562  * automatically and invokes the appropriate error response.  */
 563
 564 void __ext4_std_error(struct super_block *sb, const char *function,
 565                       unsigned int line, int errno)
 566 {
 567         char nbuf[16];
 568         const char *errstr;
 569
 570         /* Special case: if the error is EROFS, and we're not already
 571          * inside a transaction, then there's really no point in logging
 572          * an error. */
 573         if (errno == -EROFS && journal_current_handle() == NULL &&
 574             (sb->s_flags & MS_RDONLY))
 575                 return;
 576
 577         if (ext4_error_ratelimit(sb)) {
 578                 errstr = ext4_decode_error(sb, errno, nbuf);
 579                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 580                        sb->s_id, function, line, errstr);
 581         }
 582
 583         save_error_info(sb, function, line);
 584         ext4_handle_error(sb);
 585 }
 586
 587 /*
 588  * ext4_abort is a much stronger failure handler than ext4_error.  The
 589  * abort function may be used to deal with unrecoverable failures such
 590  * as journal IO errors or ENOMEM at a critical moment in log management.
 591  *
 592  * We unconditionally force the filesystem into an ABORT|READONLY state,
 593  * unless the error response on the fs has been set to panic in which
 594  * case we take the easy way out and panic immediately.
 595  */
 596
 597 void __ext4_abort(struct super_block *sb, const char *function,
 598                 unsigned int line, const char *fmt, ...)
 599 {
 600         struct va_format vaf;
 601         va_list args;
 602
 603         save_error_info(sb, function, line);
 604         va_start(args, fmt);
 605         vaf.fmt = fmt;
 606         vaf.va = &args;
 607         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
 608                sb->s_id, function, line, &vaf);
 609         va_end(args);
 610
 611         if ((sb->s_flags & MS_RDONLY) == 0) {
 612                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 613                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 614                 /*
 615                  * Make sure updated value of ->s_mount_flags will be visible
 616                  * before ->s_flags update
 617                  */
 618                 smp_wmb();
 619                 sb->s_flags |= MS_RDONLY;
 620                 if (EXT4_SB(sb)->s_journal)
 621                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 622                 save_error_info(sb, function, line);
 623         }
 624         if (test_opt(sb, ERRORS_PANIC)) {
 625                 if (EXT4_SB(sb)->s_journal &&
 626                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 627                         return;
 628                 panic("EXT4-fs panic from previous error\n");
 629         }
 630 }
 631
 632 void __ext4_msg(struct super_block *sb,
 633                 const char *prefix, const char *fmt, ...)
 634 {
 635         struct va_format vaf;
 636         va_list args;
 637
 638         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 639                 return;
 640
 641         va_start(args, fmt);
 642         vaf.fmt = fmt;
 643         vaf.va = &args;
 644         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 645         va_end(args);
 646 }
 647
 648 #define ext4_warning_ratelimit(sb)                                      \
 649                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 650                              "EXT4-fs warning")
 651
 652 void __ext4_warning(struct super_block *sb, const char *function,
 653                     unsigned int line, const char *fmt, ...)
 654 {
 655         struct va_format vaf;
 656         va_list args;
 657
 658         if (!ext4_warning_ratelimit(sb))
 659                 return;
 660
 661         va_start(args, fmt);
 662         vaf.fmt = fmt;
 663         vaf.va = &args;
 664         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 665                sb->s_id, function, line, &vaf);
 666         va_end(args);
 667 }
 668
 669 void __ext4_warning_inode(const struct inode *inode, const char *function,
 670                           unsigned int line, const char *fmt, ...)
 671 {
 672         struct va_format vaf;
 673         va_list args;
 674
 675         if (!ext4_warning_ratelimit(inode->i_sb))
 676                 return;
 677
 678         va_start(args, fmt);
 679         vaf.fmt = fmt;
 680         vaf.va = &args;
 681         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 682                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 683                function, line, inode->i_ino, current->comm, &vaf);
 684         va_end(args);
 685 }
 686
 687 void __ext4_grp_locked_error(const char *function, unsigned int line,
 688                              struct super_block *sb, ext4_group_t grp,
 689                              unsigned long ino, ext4_fsblk_t block,
 690                              const char *fmt, ...)
 691 __releases(bitlock)
 692 __acquires(bitlock)
 693 {
 694         struct va_format vaf;
 695         va_list args;
 696         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 697
 698         es->s_last_error_ino = cpu_to_le32(ino);
 699         es->s_last_error_block = cpu_to_le64(block);
 700         __save_error_info(sb, function, line);
 701
 702         if (ext4_error_ratelimit(sb)) {
 703                 va_start(args, fmt);
 704                 vaf.fmt = fmt;
 705                 vaf.va = &args;
 706                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 707                        sb->s_id, function, line, grp);
 708                 if (ino)
 709                         printk(KERN_CONT "inode %lu: ", ino);
 710                 if (block)
 711                         printk(KERN_CONT "block %llu:",
 712                                (unsigned long long) block);
 713                 printk(KERN_CONT "%pV\n", &vaf);
 714                 va_end(args);
 715         }
 716
 717         if (test_opt(sb, ERRORS_CONT)) {
 718                 ext4_commit_super(sb, 0);
 719                 return;
 720         }
 721
 722         ext4_unlock_group(sb, grp);
 723         ext4_handle_error(sb);
 724         /*
 725          * We only get here in the ERRORS_RO case; relocking the group
 726          * may be dangerous, but nothing bad will happen since the
 727          * filesystem will have already been marked read/only and the
 728          * journal has been aborted.  We return 1 as a hint to callers
 729          * who might what to use the return value from
 730          * ext4_grp_locked_error() to distinguish between the
 731          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 732          * aggressively from the ext4 function in question, with a
 733          * more appropriate error code.
 734          */
 735         ext4_lock_group(sb, grp);
 736         return;
 737 }
 738
 739 void ext4_update_dynamic_rev(struct super_block *sb)
 740 {
 741         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 742
 743         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 744                 return;
 745
 746         ext4_warning(sb,
 747                      "updating to rev %d because of new feature flag, "
 748                      "running e2fsck is recommended",
 749                      EXT4_DYNAMIC_REV);
 750
 751         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 752         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 753         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 754         /* leave es->s_feature_*compat flags alone */
 755         /* es->s_uuid will be set by e2fsck if empty */
 756
 757         /*
 758          * The rest of the superblock fields should be zero, and if not it
 759          * means they are likely already in use, so leave them alone.  We
 760          * can leave it up to e2fsck to clean up any inconsistencies there.
 761          */
 762 }
 763
 764 /*
 765  * Open the external journal device
 766  */
 767 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 768 {
 769         struct block_device *bdev;
 770         char b[BDEVNAME_SIZE];
 771
 772         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 773         if (IS_ERR(bdev))
 774                 goto fail;
 775         return bdev;
 776
 777 fail:
 778         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 779                         __bdevname(dev, b), PTR_ERR(bdev));
 780         return NULL;
 781 }
 782
 783 /*
 784  * Release the journal device
 785  */
 786 static void ext4_blkdev_put(struct block_device *bdev)
 787 {
 788         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 789 }
 790
 791 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 792 {
 793         struct block_device *bdev;
 794         bdev = sbi->journal_bdev;
 795         if (bdev) {
 796                 ext4_blkdev_put(bdev);
 797                 sbi->journal_bdev = NULL;
 798         }
 799 }
 800
 801 static inline struct inode *orphan_list_entry(struct list_head *l)
 802 {
 803         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 804 }
 805
 806 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 807 {
 808         struct list_head *l;
 809
 810         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 811                  le32_to_cpu(sbi->s_es->s_last_orphan));
 812
 813         printk(KERN_ERR "sb_info orphan list:\n");
 814         list_for_each(l, &sbi->s_orphan) {
 815                 struct inode *inode = orphan_list_entry(l);
 816                 printk(KERN_ERR "  "
 817                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 818                        inode->i_sb->s_id, inode->i_ino, inode,
 819                        inode->i_mode, inode->i_nlink,
 820                        NEXT_ORPHAN(inode));
 821         }
 822 }
 823
 824 static void ext4_put_super(struct super_block *sb)
 825 {
 826         struct ext4_sb_info *sbi = EXT4_SB(sb);
 827         struct ext4_super_block *es = sbi->s_es;
 828         int i, err;
 829
 830         ext4_unregister_li_request(sb);
 831         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 832
 833         flush_workqueue(sbi->rsv_conversion_wq);
 834         destroy_workqueue(sbi->rsv_conversion_wq);
 835
 836         if (sbi->s_journal) {
 837                 err = jbd2_journal_destroy(sbi->s_journal);
 838                 sbi->s_journal = NULL;
 839                 if (err < 0)
 840                         ext4_abort(sb, "Couldn't clean up the journal");
 841         }
 842
 843         ext4_unregister_sysfs(sb);
 844         ext4_es_unregister_shrinker(sbi);
 845         del_timer_sync(&sbi->s_err_report);
 846         ext4_release_system_zone(sb);
 847         ext4_mb_release(sb);
 848         ext4_ext_release(sb);
 849
 850         if (!(sb->s_flags & MS_RDONLY)) {
 851                 ext4_clear_feature_journal_needs_recovery(sb);
 852                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 853         }
 854         if (!(sb->s_flags & MS_RDONLY))
 855                 ext4_commit_super(sb, 1);
 856
 857         for (i = 0; i < sbi->s_gdb_count; i++)
 858                 brelse(sbi->s_group_desc[i]);
 859         kvfree(sbi->s_group_desc);
 860         kvfree(sbi->s_flex_groups);
 861         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 862         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 863         percpu_counter_destroy(&sbi->s_dirs_counter);
 864         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 865         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 866 #ifdef CONFIG_QUOTA
 867         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 868                 kfree(sbi->s_qf_names[i]);
 869 #endif
 870
 871         /* Debugging code just in case the in-memory inode orphan list
 872          * isn't empty.  The on-disk one can be non-empty if we've
 873          * detected an error and taken the fs readonly, but the
 874          * in-memory list had better be clean by this point. */
 875         if (!list_empty(&sbi->s_orphan))
 876                 dump_orphan_list(sb, sbi);
 877         J_ASSERT(list_empty(&sbi->s_orphan));
 878
 879         sync_blockdev(sb->s_bdev);
 880         invalidate_bdev(sb->s_bdev);
 881         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 882                 /*
 883                  * Invalidate the journal device's buffers.  We don't want them
 884                  * floating about in memory - the physical journal device may
 885                  * hotswapped, and it breaks the `ro-after' testing code.
 886                  */
 887                 sync_blockdev(sbi->journal_bdev);
 888                 invalidate_bdev(sbi->journal_bdev);
 889                 ext4_blkdev_remove(sbi);
 890         }
 891         if (sbi->s_mb_cache) {
 892                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
 893                 sbi->s_mb_cache = NULL;
 894         }
 895         if (sbi->s_mmp_tsk)
 896                 kthread_stop(sbi->s_mmp_tsk);
 897         brelse(sbi->s_sbh);
 898         sb->s_fs_info = NULL;
 899         /*
 900          * Now that we are completely done shutting down the
 901          * superblock, we need to actually destroy the kobject.
 902          */
 903         kobject_put(&sbi->s_kobj);
 904         wait_for_completion(&sbi->s_kobj_unregister);
 905         if (sbi->s_chksum_driver)
 906                 crypto_free_shash(sbi->s_chksum_driver);
 907         kfree(sbi->s_blockgroup_lock);
 908         kfree(sbi);
 909 }
 910
 911 static struct kmem_cache *ext4_inode_cachep;
 912
 913 /*
 914  * Called inside transaction, so use GFP_NOFS
 915  */
 916 static struct inode *ext4_alloc_inode(struct super_block *sb)
 917 {
 918         struct ext4_inode_info *ei;
 919
 920         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 921         if (!ei)
 922                 return NULL;
 923
 924         ei->vfs_inode.i_version = 1;
 925         spin_lock_init(&ei->i_raw_lock);
 926         INIT_LIST_HEAD(&ei->i_prealloc_list);
 927         spin_lock_init(&ei->i_prealloc_lock);
 928         ext4_es_init_tree(&ei->i_es_tree);
 929         rwlock_init(&ei->i_es_lock);
 930         INIT_LIST_HEAD(&ei->i_es_list);
 931         ei->i_es_all_nr = 0;
 932         ei->i_es_shk_nr = 0;
 933         ei->i_es_shrink_lblk = 0;
 934         ei->i_reserved_data_blocks = 0;
 935         ei->i_reserved_meta_blocks = 0;
 936         ei->i_allocated_meta_blocks = 0;
 937         ei->i_da_metadata_calc_len = 0;
 938         ei->i_da_metadata_calc_last_lblock = 0;
 939         spin_lock_init(&(ei->i_block_reservation_lock));
 940 #ifdef CONFIG_QUOTA
 941         ei->i_reserved_quota = 0;
 942         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 943 #endif
 944         ei->jinode = NULL;
 945         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 946         spin_lock_init(&ei->i_completed_io_lock);
 947         ei->i_sync_tid = 0;
 948         ei->i_datasync_tid = 0;
 949         atomic_set(&ei->i_unwritten, 0);
 950         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 951         return &ei->vfs_inode;
 952 }
 953
 954 static int ext4_drop_inode(struct inode *inode)
 955 {
 956         int drop = generic_drop_inode(inode);
 957
 958         trace_ext4_drop_inode(inode, drop);
 959         return drop;
 960 }
 961
 962 static void ext4_i_callback(struct rcu_head *head)
 963 {
 964         struct inode *inode = container_of(head, struct inode, i_rcu);
 965         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 966 }
 967
 968 static void ext4_destroy_inode(struct inode *inode)
 969 {
 970         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 971                 ext4_msg(inode->i_sb, KERN_ERR,
 972                          "Inode %lu (%p): orphan list check failed!",
 973                          inode->i_ino, EXT4_I(inode));
 974                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 975                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 976                                 true);
 977                 dump_stack();
 978         }
 979         call_rcu(&inode->i_rcu, ext4_i_callback);
 980 }
 981
 982 static void init_once(void *foo)
 983 {
 984         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 985
 986         INIT_LIST_HEAD(&ei->i_orphan);
 987         init_rwsem(&ei->xattr_sem);
 988         init_rwsem(&ei->i_data_sem);
 989         init_rwsem(&ei->i_mmap_sem);
 990         inode_init_once(&ei->vfs_inode);
 991 }
 992
 993 static int __init init_inodecache(void)
 994 {
 995         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 996                                              sizeof(struct ext4_inode_info),
 997                                              0, (SLAB_RECLAIM_ACCOUNT|
 998                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 999                                              init_once);
1000         if (ext4_inode_cachep == NULL)
1001                 return -ENOMEM;
1002         return 0;
1003 }
1004
1005 static void destroy_inodecache(void)
1006 {
1007         /*
1008          * Make sure all delayed rcu free inodes are flushed before we
1009          * destroy cache.
1010          */
1011         rcu_barrier();
1012         kmem_cache_destroy(ext4_inode_cachep);
1013 }
1014
1015 void ext4_clear_inode(struct inode *inode)
1016 {
1017         invalidate_inode_buffers(inode);
1018         clear_inode(inode);
1019         dquot_drop(inode);
1020         ext4_discard_preallocations(inode);
1021         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1022         if (EXT4_I(inode)->jinode) {
1023                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1024                                                EXT4_I(inode)->jinode);
1025                 jbd2_free_inode(EXT4_I(inode)->jinode);
1026                 EXT4_I(inode)->jinode = NULL;
1027         }
1028 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1029         fscrypt_put_encryption_info(inode, NULL);
1030 #endif
1031 }
1032
1033 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1034                                         u64 ino, u32 generation)
1035 {
1036         struct inode *inode;
1037
1038         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1039                 return ERR_PTR(-ESTALE);
1040         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1041                 return ERR_PTR(-ESTALE);
1042
1043         /* iget isn't really right if the inode is currently unallocated!!
1044          *
1045          * ext4_read_inode will return a bad_inode if the inode had been
1046          * deleted, so we should be safe.
1047          *
1048          * Currently we don't know the generation for parent directory, so
1049          * a generation of 0 means "accept any"
1050          */
1051         inode = ext4_iget_normal(sb, ino);
1052         if (IS_ERR(inode))
1053                 return ERR_CAST(inode);
1054         if (generation && inode->i_generation != generation) {
1055                 iput(inode);
1056                 return ERR_PTR(-ESTALE);
1057         }
1058
1059         return inode;
1060 }
1061
1062 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1063                                         int fh_len, int fh_type)
1064 {
1065         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1066                                     ext4_nfs_get_inode);
1067 }
1068
1069 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1070                                         int fh_len, int fh_type)
1071 {
1072         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1073                                     ext4_nfs_get_inode);
1074 }
1075
1076 /*
1077  * Try to release metadata pages (indirect blocks, directories) which are
1078  * mapped via the block device.  Since these pages could have journal heads
1079  * which would prevent try_to_free_buffers() from freeing them, we must use
1080  * jbd2 layer's try_to_free_buffers() function to release them.
1081  */
1082 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1083                                  gfp_t wait)
1084 {
1085         journal_t *journal = EXT4_SB(sb)->s_journal;
1086
1087         WARN_ON(PageChecked(page));
1088         if (!page_has_buffers(page))
1089                 return 0;
1090         if (journal)
1091                 return jbd2_journal_try_to_free_buffers(journal, page,
1092                                                 wait & ~__GFP_DIRECT_RECLAIM);
1093         return try_to_free_buffers(page);
1094 }
1095
1096 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1097 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1098 {
1099         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1100                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1101 }
1102
1103 static int ext4_key_prefix(struct inode *inode, u8 **key)
1104 {
1105         *key = EXT4_SB(inode->i_sb)->key_prefix;
1106         return EXT4_SB(inode->i_sb)->key_prefix_size;
1107 }
1108
1109 static int ext4_prepare_context(struct inode *inode)
1110 {
1111         return ext4_convert_inline_data(inode);
1112 }
1113
1114 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1115                                                         void *fs_data)
1116 {
1117         handle_t *handle = fs_data;
1118         int res, res2, retries = 0;
1119
1120         /*
1121          * If a journal handle was specified, then the encryption context is
1122          * being set on a new inode via inheritance and is part of a larger
1123          * transaction to create the inode.  Otherwise the encryption context is
1124          * being set on an existing inode in its own transaction.  Only in the
1125          * latter case should the "retry on ENOSPC" logic be used.
1126          */
1127
1128         if (handle) {
1129                 res = ext4_xattr_set_handle(handle, inode,
1130                                             EXT4_XATTR_INDEX_ENCRYPTION,
1131                                             EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1132                                             ctx, len, 0);
1133                 if (!res) {
1134                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1135                         ext4_clear_inode_state(inode,
1136                                         EXT4_STATE_MAY_INLINE_DATA);
1137                         /*
1138                          * Update inode->i_flags - e.g. S_DAX may get disabled
1139                          */
1140                         ext4_set_inode_flags(inode);
1141                 }
1142                 return res;
1143         }
1144
1145 retry:
1146         handle = ext4_journal_start(inode, EXT4_HT_MISC,
1147                         ext4_jbd2_credits_xattr(inode));
1148         if (IS_ERR(handle))
1149                 return PTR_ERR(handle);
1150
1151         res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1152                                     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1153                                     ctx, len, 0);
1154         if (!res) {
1155                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1156                 /* Update inode->i_flags - e.g. S_DAX may get disabled */
1157                 ext4_set_inode_flags(inode);
1158                 res = ext4_mark_inode_dirty(handle, inode);
1159                 if (res)
1160                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1161         }
1162         res2 = ext4_journal_stop(handle);
1163
1164         if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1165                 goto retry;
1166         if (!res)
1167                 res = res2;
1168         return res;
1169 }
1170
1171 static int ext4_dummy_context(struct inode *inode)
1172 {
1173         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1174 }
1175
1176 static unsigned ext4_max_namelen(struct inode *inode)
1177 {
1178         return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1179                 EXT4_NAME_LEN;
1180 }
1181
1182 static struct fscrypt_operations ext4_cryptops = {
1183         .get_context            = ext4_get_context,
1184         .key_prefix             = ext4_key_prefix,
1185         .prepare_context        = ext4_prepare_context,
1186         .set_context            = ext4_set_context,
1187         .dummy_context          = ext4_dummy_context,
1188         .is_encrypted           = ext4_encrypted_inode,
1189         .empty_dir              = ext4_empty_dir,
1190         .max_namelen            = ext4_max_namelen,
1191 };
1192 #else
1193 static struct fscrypt_operations ext4_cryptops = {
1194         .is_encrypted           = ext4_encrypted_inode,
1195 };
1196 #endif
1197
1198 #ifdef CONFIG_QUOTA
1199 static char *quotatypes[] = INITQFNAMES;
1200 #define QTYPE2NAME(t) (quotatypes[t])
1201
1202 static int ext4_write_dquot(struct dquot *dquot);
1203 static int ext4_acquire_dquot(struct dquot *dquot);
1204 static int ext4_release_dquot(struct dquot *dquot);
1205 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1206 static int ext4_write_info(struct super_block *sb, int type);
1207 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1208                          const struct path *path);
1209 static int ext4_quota_off(struct super_block *sb, int type);
1210 static int ext4_quota_on_mount(struct super_block *sb, int type);
1211 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1212                                size_t len, loff_t off);
1213 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1214                                 const char *data, size_t len, loff_t off);
1215 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1216                              unsigned int flags);
1217 static int ext4_enable_quotas(struct super_block *sb);
1218 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1219
1220 static struct dquot **ext4_get_dquots(struct inode *inode)
1221 {
1222         return EXT4_I(inode)->i_dquot;
1223 }
1224
1225 static const struct dquot_operations ext4_quota_operations = {
1226         .get_reserved_space = ext4_get_reserved_space,
1227         .write_dquot    = ext4_write_dquot,
1228         .acquire_dquot  = ext4_acquire_dquot,
1229         .release_dquot  = ext4_release_dquot,
1230         .mark_dirty     = ext4_mark_dquot_dirty,
1231         .write_info     = ext4_write_info,
1232         .alloc_dquot    = dquot_alloc,
1233         .destroy_dquot  = dquot_destroy,
1234         .get_projid     = ext4_get_projid,
1235         .get_next_id    = ext4_get_next_id,
1236 };
1237
1238 static const struct quotactl_ops ext4_qctl_operations = {
1239         .quota_on       = ext4_quota_on,
1240         .quota_off      = ext4_quota_off,
1241         .quota_sync     = dquot_quota_sync,
1242         .get_state      = dquot_get_state,
1243         .set_info       = dquot_set_dqinfo,
1244         .get_dqblk      = dquot_get_dqblk,
1245         .set_dqblk      = dquot_set_dqblk,
1246         .get_nextdqblk  = dquot_get_next_dqblk,
1247 };
1248 #endif
1249
1250 static const struct super_operations ext4_sops = {
1251         .alloc_inode    = ext4_alloc_inode,
1252         .destroy_inode  = ext4_destroy_inode,
1253         .write_inode    = ext4_write_inode,
1254         .dirty_inode    = ext4_dirty_inode,
1255         .drop_inode     = ext4_drop_inode,
1256         .evict_inode    = ext4_evict_inode,
1257         .put_super      = ext4_put_super,
1258         .sync_fs        = ext4_sync_fs,
1259         .freeze_fs      = ext4_freeze,
1260         .unfreeze_fs    = ext4_unfreeze,
1261         .statfs         = ext4_statfs,
1262         .remount_fs     = ext4_remount,
1263         .show_options   = ext4_show_options,
1264 #ifdef CONFIG_QUOTA
1265         .quota_read     = ext4_quota_read,
1266         .quota_write    = ext4_quota_write,
1267         .get_dquots     = ext4_get_dquots,
1268 #endif
1269         .bdev_try_to_free_page = bdev_try_to_free_page,
1270 };
1271
1272 static const struct export_operations ext4_export_ops = {
1273         .fh_to_dentry = ext4_fh_to_dentry,
1274         .fh_to_parent = ext4_fh_to_parent,
1275         .get_parent = ext4_get_parent,
1276 };
1277
1278 enum {
1279         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1280         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1281         Opt_nouid32, Opt_debug, Opt_removed,
1282         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1283         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1284         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1285         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1286         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1287         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1288         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1289         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1290         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1291         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1292         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1293         Opt_lazytime, Opt_nolazytime,
1294         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1295         Opt_inode_readahead_blks, Opt_journal_ioprio,
1296         Opt_dioread_nolock, Opt_dioread_lock,
1297         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1298         Opt_max_dir_size_kb, Opt_nojournal_checksum,
1299 };
1300
1301 static const match_table_t tokens = {
1302         {Opt_bsd_df, "bsddf"},
1303         {Opt_minix_df, "minixdf"},
1304         {Opt_grpid, "grpid"},
1305         {Opt_grpid, "bsdgroups"},
1306         {Opt_nogrpid, "nogrpid"},
1307         {Opt_nogrpid, "sysvgroups"},
1308         {Opt_resgid, "resgid=%u"},
1309         {Opt_resuid, "resuid=%u"},
1310         {Opt_sb, "sb=%u"},
1311         {Opt_err_cont, "errors=continue"},
1312         {Opt_err_panic, "errors=panic"},
1313         {Opt_err_ro, "errors=remount-ro"},
1314         {Opt_nouid32, "nouid32"},
1315         {Opt_debug, "debug"},
1316         {Opt_removed, "oldalloc"},
1317         {Opt_removed, "orlov"},
1318         {Opt_user_xattr, "user_xattr"},
1319         {Opt_nouser_xattr, "nouser_xattr"},
1320         {Opt_acl, "acl"},
1321         {Opt_noacl, "noacl"},
1322         {Opt_noload, "norecovery"},
1323         {Opt_noload, "noload"},
1324         {Opt_removed, "nobh"},
1325         {Opt_removed, "bh"},
1326         {Opt_commit, "commit=%u"},
1327         {Opt_min_batch_time, "min_batch_time=%u"},
1328         {Opt_max_batch_time, "max_batch_time=%u"},
1329         {Opt_journal_dev, "journal_dev=%u"},
1330         {Opt_journal_path, "journal_path=%s"},
1331         {Opt_journal_checksum, "journal_checksum"},
1332         {Opt_nojournal_checksum, "nojournal_checksum"},
1333         {Opt_journal_async_commit, "journal_async_commit"},
1334         {Opt_abort, "abort"},
1335         {Opt_data_journal, "data=journal"},
1336         {Opt_data_ordered, "data=ordered"},
1337         {Opt_data_writeback, "data=writeback"},
1338         {Opt_data_err_abort, "data_err=abort"},
1339         {Opt_data_err_ignore, "data_err=ignore"},
1340         {Opt_offusrjquota, "usrjquota="},
1341         {Opt_usrjquota, "usrjquota=%s"},
1342         {Opt_offgrpjquota, "grpjquota="},
1343         {Opt_grpjquota, "grpjquota=%s"},
1344         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1345         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1346         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1347         {Opt_grpquota, "grpquota"},
1348         {Opt_noquota, "noquota"},
1349         {Opt_quota, "quota"},
1350         {Opt_usrquota, "usrquota"},
1351         {Opt_prjquota, "prjquota"},
1352         {Opt_barrier, "barrier=%u"},
1353         {Opt_barrier, "barrier"},
1354         {Opt_nobarrier, "nobarrier"},
1355         {Opt_i_version, "i_version"},
1356         {Opt_dax, "dax"},
1357         {Opt_stripe, "stripe=%u"},
1358         {Opt_delalloc, "delalloc"},
1359         {Opt_lazytime, "lazytime"},
1360         {Opt_nolazytime, "nolazytime"},
1361         {Opt_nodelalloc, "nodelalloc"},
1362         {Opt_removed, "mblk_io_submit"},
1363         {Opt_removed, "nomblk_io_submit"},
1364         {Opt_block_validity, "block_validity"},
1365         {Opt_noblock_validity, "noblock_validity"},
1366         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1367         {Opt_journal_ioprio, "journal_ioprio=%u"},
1368         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1369         {Opt_auto_da_alloc, "auto_da_alloc"},
1370         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1371         {Opt_dioread_nolock, "dioread_nolock"},
1372         {Opt_dioread_lock, "dioread_lock"},
1373         {Opt_discard, "discard"},
1374         {Opt_nodiscard, "nodiscard"},
1375         {Opt_init_itable, "init_itable=%u"},
1376         {Opt_init_itable, "init_itable"},
1377         {Opt_noinit_itable, "noinit_itable"},
1378         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1379         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1380         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1381         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1382         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1383         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1384         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1385         {Opt_err, NULL},
1386 };
1387
1388 static ext4_fsblk_t get_sb_block(void **data)
1389 {
1390         ext4_fsblk_t    sb_block;
1391         char            *options = (char *) *data;
1392
1393         if (!options || strncmp(options, "sb=", 3) != 0)
1394                 return 1;       /* Default location */
1395
1396         options += 3;
1397         /* TODO: use simple_strtoll with >32bit ext4 */
1398         sb_block = simple_strtoul(options, &options, 0);
1399         if (*options && *options != ',') {
1400                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1401                        (char *) *data);
1402                 return 1;
1403         }
1404         if (*options == ',')
1405                 options++;
1406         *data = (void *) options;
1407
1408         return sb_block;
1409 }
1410
1411 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1412 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1413         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1414
1415 #ifdef CONFIG_QUOTA
1416 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1417 {
1418         struct ext4_sb_info *sbi = EXT4_SB(sb);
1419         char *qname;
1420         int ret = -1;
1421
1422         if (sb_any_quota_loaded(sb) &&
1423                 !sbi->s_qf_names[qtype]) {
1424                 ext4_msg(sb, KERN_ERR,
1425                         "Cannot change journaled "
1426                         "quota options when quota turned on");
1427                 return -1;
1428         }
1429         if (ext4_has_feature_quota(sb)) {
1430                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1431                          "ignored when QUOTA feature is enabled");
1432                 return 1;
1433         }
1434         qname = match_strdup(args);
1435         if (!qname) {
1436                 ext4_msg(sb, KERN_ERR,
1437                         "Not enough memory for storing quotafile name");
1438                 return -1;
1439         }
1440         if (sbi->s_qf_names[qtype]) {
1441                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1442                         ret = 1;
1443                 else
1444                         ext4_msg(sb, KERN_ERR,
1445                                  "%s quota file already specified",
1446                                  QTYPE2NAME(qtype));
1447                 goto errout;
1448         }
1449         if (strchr(qname, '/')) {
1450                 ext4_msg(sb, KERN_ERR,
1451                         "quotafile must be on filesystem root");
1452                 goto errout;
1453         }
1454         sbi->s_qf_names[qtype] = qname;
1455         set_opt(sb, QUOTA);
1456         return 1;
1457 errout:
1458         kfree(qname);
1459         return ret;
1460 }
1461
1462 static int clear_qf_name(struct super_block *sb, int qtype)
1463 {
1464
1465         struct ext4_sb_info *sbi = EXT4_SB(sb);
1466
1467         if (sb_any_quota_loaded(sb) &&
1468                 sbi->s_qf_names[qtype]) {
1469                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1470                         " when quota turned on");
1471                 return -1;
1472         }
1473         kfree(sbi->s_qf_names[qtype]);
1474         sbi->s_qf_names[qtype] = NULL;
1475         return 1;
1476 }
1477 #endif
1478
1479 #define MOPT_SET        0x0001
1480 #define MOPT_CLEAR      0x0002
1481 #define MOPT_NOSUPPORT  0x0004
1482 #define MOPT_EXPLICIT   0x0008
1483 #define MOPT_CLEAR_ERR  0x0010
1484 #define MOPT_GTE0       0x0020
1485 #ifdef CONFIG_QUOTA
1486 #define MOPT_Q          0
1487 #define MOPT_QFMT       0x0040
1488 #else
1489 #define MOPT_Q          MOPT_NOSUPPORT
1490 #define MOPT_QFMT       MOPT_NOSUPPORT
1491 #endif
1492 #define MOPT_DATAJ      0x0080
1493 #define MOPT_NO_EXT2    0x0100
1494 #define MOPT_NO_EXT3    0x0200
1495 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1496 #define MOPT_STRING     0x0400
1497
1498 static const struct mount_opts {
1499         int     token;
1500         int     mount_opt;
1501         int     flags;
1502 } ext4_mount_opts[] = {
1503         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1504         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1505         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1506         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1507         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1508         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1509         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1510          MOPT_EXT4_ONLY | MOPT_SET},
1511         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1512          MOPT_EXT4_ONLY | MOPT_CLEAR},
1513         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1514         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1515         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1516          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1517         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1518          MOPT_EXT4_ONLY | MOPT_CLEAR},
1519         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1520          MOPT_EXT4_ONLY | MOPT_CLEAR},
1521         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1522          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1523         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1524                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1525          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1526         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1527         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1528         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1529         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1530         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1531          MOPT_NO_EXT2},
1532         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1533          MOPT_NO_EXT2},
1534         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1535         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1536         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1537         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1538         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1539         {Opt_commit, 0, MOPT_GTE0},
1540         {Opt_max_batch_time, 0, MOPT_GTE0},
1541         {Opt_min_batch_time, 0, MOPT_GTE0},
1542         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1543         {Opt_init_itable, 0, MOPT_GTE0},
1544         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1545         {Opt_stripe, 0, MOPT_GTE0},
1546         {Opt_resuid, 0, MOPT_GTE0},
1547         {Opt_resgid, 0, MOPT_GTE0},
1548         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1549         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1550         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1551         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1552         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1553         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1554          MOPT_NO_EXT2 | MOPT_DATAJ},
1555         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1556         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1557 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1558         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1559         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1560 #else
1561         {Opt_acl, 0, MOPT_NOSUPPORT},
1562         {Opt_noacl, 0, MOPT_NOSUPPORT},
1563 #endif
1564         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1565         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1566         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1567         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1568                                                         MOPT_SET | MOPT_Q},
1569         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1570                                                         MOPT_SET | MOPT_Q},
1571         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1572                                                         MOPT_SET | MOPT_Q},
1573         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1574                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1575                                                         MOPT_CLEAR | MOPT_Q},
1576         {Opt_usrjquota, 0, MOPT_Q},
1577         {Opt_grpjquota, 0, MOPT_Q},
1578         {Opt_offusrjquota, 0, MOPT_Q},
1579         {Opt_offgrpjquota, 0, MOPT_Q},
1580         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1581         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1582         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1583         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1584         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1585         {Opt_err, 0, 0}
1586 };
1587
1588 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1589                             substring_t *args, unsigned long *journal_devnum,
1590                             unsigned int *journal_ioprio, int is_remount)
1591 {
1592         struct ext4_sb_info *sbi = EXT4_SB(sb);
1593         const struct mount_opts *m;
1594         kuid_t uid;
1595         kgid_t gid;
1596         int arg = 0;
1597
1598 #ifdef CONFIG_QUOTA
1599         if (token == Opt_usrjquota)
1600                 return set_qf_name(sb, USRQUOTA, &args[0]);
1601         else if (token == Opt_grpjquota)
1602                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1603         else if (token == Opt_offusrjquota)
1604                 return clear_qf_name(sb, USRQUOTA);
1605         else if (token == Opt_offgrpjquota)
1606                 return clear_qf_name(sb, GRPQUOTA);
1607 #endif
1608         switch (token) {
1609         case Opt_noacl:
1610         case Opt_nouser_xattr:
1611                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1612                 break;
1613         case Opt_sb:
1614                 return 1;       /* handled by get_sb_block() */
1615         case Opt_removed:
1616                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1617                 return 1;
1618         case Opt_abort:
1619                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1620                 return 1;
1621         case Opt_i_version:
1622                 sb->s_flags |= MS_I_VERSION;
1623                 return 1;
1624         case Opt_lazytime:
1625                 sb->s_flags |= MS_LAZYTIME;
1626                 return 1;
1627         case Opt_nolazytime:
1628                 sb->s_flags &= ~MS_LAZYTIME;
1629                 return 1;
1630         }
1631
1632         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1633                 if (token == m->token)
1634                         break;
1635
1636         if (m->token == Opt_err) {
1637                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1638                          "or missing value", opt);
1639                 return -1;
1640         }
1641
1642         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1643                 ext4_msg(sb, KERN_ERR,
1644                          "Mount option \"%s\" incompatible with ext2", opt);
1645                 return -1;
1646         }
1647         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1648                 ext4_msg(sb, KERN_ERR,
1649                          "Mount option \"%s\" incompatible with ext3", opt);
1650                 return -1;
1651         }
1652
1653         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1654                 return -1;
1655         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1656                 return -1;
1657         if (m->flags & MOPT_EXPLICIT) {
1658                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1659                         set_opt2(sb, EXPLICIT_DELALLOC);
1660                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1661                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1662                 } else
1663                         return -1;
1664         }
1665         if (m->flags & MOPT_CLEAR_ERR)
1666                 clear_opt(sb, ERRORS_MASK);
1667         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1668                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1669                          "options when quota turned on");
1670                 return -1;
1671         }
1672
1673         if (m->flags & MOPT_NOSUPPORT) {
1674                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1675         } else if (token == Opt_commit) {
1676                 if (arg == 0)
1677                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1678                 sbi->s_commit_interval = HZ * arg;
1679         } else if (token == Opt_max_batch_time) {
1680                 sbi->s_max_batch_time = arg;
1681         } else if (token == Opt_min_batch_time) {
1682                 sbi->s_min_batch_time = arg;
1683         } else if (token == Opt_inode_readahead_blks) {
1684                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1685                         ext4_msg(sb, KERN_ERR,
1686                                  "EXT4-fs: inode_readahead_blks must be "
1687                                  "0 or a power of 2 smaller than 2^31");
1688                         return -1;
1689                 }
1690                 sbi->s_inode_readahead_blks = arg;
1691         } else if (token == Opt_init_itable) {
1692                 set_opt(sb, INIT_INODE_TABLE);
1693                 if (!args->from)
1694                         arg = EXT4_DEF_LI_WAIT_MULT;
1695                 sbi->s_li_wait_mult = arg;
1696         } else if (token == Opt_max_dir_size_kb) {
1697                 sbi->s_max_dir_size_kb = arg;
1698         } else if (token == Opt_stripe) {
1699                 sbi->s_stripe = arg;
1700         } else if (token == Opt_resuid) {
1701                 uid = make_kuid(current_user_ns(), arg);
1702                 if (!uid_valid(uid)) {
1703                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1704                         return -1;
1705                 }
1706                 sbi->s_resuid = uid;
1707         } else if (token == Opt_resgid) {
1708                 gid = make_kgid(current_user_ns(), arg);
1709                 if (!gid_valid(gid)) {
1710                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1711                         return -1;
1712                 }
1713                 sbi->s_resgid = gid;
1714         } else if (token == Opt_journal_dev) {
1715                 if (is_remount) {
1716                         ext4_msg(sb, KERN_ERR,
1717                                  "Cannot specify journal on remount");
1718                         return -1;
1719                 }
1720                 *journal_devnum = arg;
1721         } else if (token == Opt_journal_path) {
1722                 char *journal_path;
1723                 struct inode *journal_inode;
1724                 struct path path;
1725                 int error;
1726
1727                 if (is_remount) {
1728                         ext4_msg(sb, KERN_ERR,
1729                                  "Cannot specify journal on remount");
1730                         return -1;
1731                 }
1732                 journal_path = match_strdup(&args[0]);
1733                 if (!journal_path) {
1734                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1735                                 "journal device string");
1736                         return -1;
1737                 }
1738
1739                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1740                 if (error) {
1741                         ext4_msg(sb, KERN_ERR, "error: could not find "
1742                                 "journal device path: error %d", error);
1743                         kfree(journal_path);
1744                         return -1;
1745                 }
1746
1747                 journal_inode = d_inode(path.dentry);
1748                 if (!S_ISBLK(journal_inode->i_mode)) {
1749                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1750                                 "is not a block device", journal_path);
1751                         path_put(&path);
1752                         kfree(journal_path);
1753                         return -1;
1754                 }
1755
1756                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1757                 path_put(&path);
1758                 kfree(journal_path);
1759         } else if (token == Opt_journal_ioprio) {
1760                 if (arg > 7) {
1761                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1762                                  " (must be 0-7)");
1763                         return -1;
1764                 }
1765                 *journal_ioprio =
1766                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1767         } else if (token == Opt_test_dummy_encryption) {
1768 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1769                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1770                 ext4_msg(sb, KERN_WARNING,
1771                          "Test dummy encryption mode enabled");
1772 #else
1773                 ext4_msg(sb, KERN_WARNING,
1774                          "Test dummy encryption mount option ignored");
1775 #endif
1776         } else if (m->flags & MOPT_DATAJ) {
1777                 if (is_remount) {
1778                         if (!sbi->s_journal)
1779                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1780                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1781                                 ext4_msg(sb, KERN_ERR,
1782                                          "Cannot change data mode on remount");
1783                                 return -1;
1784                         }
1785                 } else {
1786                         clear_opt(sb, DATA_FLAGS);
1787                         sbi->s_mount_opt |= m->mount_opt;
1788                 }
1789 #ifdef CONFIG_QUOTA
1790         } else if (m->flags & MOPT_QFMT) {
1791                 if (sb_any_quota_loaded(sb) &&
1792                     sbi->s_jquota_fmt != m->mount_opt) {
1793                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1794                                  "quota options when quota turned on");
1795                         return -1;
1796                 }
1797                 if (ext4_has_feature_quota(sb)) {
1798                         ext4_msg(sb, KERN_INFO,
1799                                  "Quota format mount options ignored "
1800                                  "when QUOTA feature is enabled");
1801                         return 1;
1802                 }
1803                 sbi->s_jquota_fmt = m->mount_opt;
1804 #endif
1805         } else if (token == Opt_dax) {
1806 #ifdef CONFIG_FS_DAX
1807                 ext4_msg(sb, KERN_WARNING,
1808                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1809                         sbi->s_mount_opt |= m->mount_opt;
1810 #else
1811                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1812                 return -1;
1813 #endif
1814         } else if (token == Opt_data_err_abort) {
1815                 sbi->s_mount_opt |= m->mount_opt;
1816         } else if (token == Opt_data_err_ignore) {
1817                 sbi->s_mount_opt &= ~m->mount_opt;
1818         } else {
1819                 if (!args->from)
1820                         arg = 1;
1821                 if (m->flags & MOPT_CLEAR)
1822                         arg = !arg;
1823                 else if (unlikely(!(m->flags & MOPT_SET))) {
1824                         ext4_msg(sb, KERN_WARNING,
1825                                  "buggy handling of option %s", opt);
1826                         WARN_ON(1);
1827                         return -1;
1828                 }
1829                 if (arg != 0)
1830                         sbi->s_mount_opt |= m->mount_opt;
1831                 else
1832                         sbi->s_mount_opt &= ~m->mount_opt;
1833         }
1834         return 1;
1835 }
1836
1837 static int parse_options(char *options, struct super_block *sb,
1838                          unsigned long *journal_devnum,
1839                          unsigned int *journal_ioprio,
1840                          int is_remount)
1841 {
1842         struct ext4_sb_info *sbi = EXT4_SB(sb);
1843         char *p;
1844         substring_t args[MAX_OPT_ARGS];
1845         int token;
1846
1847         if (!options)
1848                 return 1;
1849
1850         while ((p = strsep(&options, ",")) != NULL) {
1851                 if (!*p)
1852                         continue;
1853                 /*
1854                  * Initialize args struct so we know whether arg was
1855                  * found; some options take optional arguments.
1856                  */
1857                 args[0].to = args[0].from = NULL;
1858                 token = match_token(p, tokens, args);
1859                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1860                                      journal_ioprio, is_remount) < 0)
1861                         return 0;
1862         }
1863 #ifdef CONFIG_QUOTA
1864         /*
1865          * We do the test below only for project quotas. 'usrquota' and
1866          * 'grpquota' mount options are allowed even without quota feature
1867          * to support legacy quotas in quota files.
1868          */
1869         if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1870                 ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1871                          "Cannot enable project quota enforcement.");
1872                 return 0;
1873         }
1874         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1875                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1876                         clear_opt(sb, USRQUOTA);
1877
1878                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1879                         clear_opt(sb, GRPQUOTA);
1880
1881                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1882                         ext4_msg(sb, KERN_ERR, "old and new quota "
1883                                         "format mixing");
1884                         return 0;
1885                 }
1886
1887                 if (!sbi->s_jquota_fmt) {
1888                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1889                                         "not specified");
1890                         return 0;
1891                 }
1892         }
1893 #endif
1894         if (test_opt(sb, DIOREAD_NOLOCK)) {
1895                 int blocksize =
1896                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1897
1898                 if (blocksize < PAGE_SIZE) {
1899                         ext4_msg(sb, KERN_ERR, "can't mount with "
1900                                  "dioread_nolock if block size != PAGE_SIZE");
1901                         return 0;
1902                 }
1903         }
1904         return 1;
1905 }
1906
1907 static inline void ext4_show_quota_options(struct seq_file *seq,
1908                                            struct super_block *sb)
1909 {
1910 #if defined(CONFIG_QUOTA)
1911         struct ext4_sb_info *sbi = EXT4_SB(sb);
1912
1913         if (sbi->s_jquota_fmt) {
1914                 char *fmtname = "";
1915
1916                 switch (sbi->s_jquota_fmt) {
1917                 case QFMT_VFS_OLD:
1918                         fmtname = "vfsold";
1919                         break;
1920                 case QFMT_VFS_V0:
1921                         fmtname = "vfsv0";
1922                         break;
1923                 case QFMT_VFS_V1:
1924                         fmtname = "vfsv1";
1925                         break;
1926                 }
1927                 seq_printf(seq, ",jqfmt=%s", fmtname);
1928         }
1929
1930         if (sbi->s_qf_names[USRQUOTA])
1931                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1932
1933         if (sbi->s_qf_names[GRPQUOTA])
1934                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1935 #endif
1936 }
1937
1938 static const char *token2str(int token)
1939 {
1940         const struct match_token *t;
1941
1942         for (t = tokens; t->token != Opt_err; t++)
1943                 if (t->token == token && !strchr(t->pattern, '='))
1944                         break;
1945         return t->pattern;
1946 }
1947
1948 /*
1949  * Show an option if
1950  *  - it's set to a non-default value OR
1951  *  - if the per-sb default is different from the global default
1952  */
1953 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1954                               int nodefs)
1955 {
1956         struct ext4_sb_info *sbi = EXT4_SB(sb);
1957         struct ext4_super_block *es = sbi->s_es;
1958         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1959         const struct mount_opts *m;
1960         char sep = nodefs ? '\n' : ',';
1961
1962 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1963 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1964
1965         if (sbi->s_sb_block != 1)
1966                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1967
1968         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1969                 int want_set = m->flags & MOPT_SET;
1970                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1971                     (m->flags & MOPT_CLEAR_ERR))
1972                         continue;
1973                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1974                         continue; /* skip if same as the default */
1975                 if ((want_set &&
1976                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1977                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1978                         continue; /* select Opt_noFoo vs Opt_Foo */
1979                 SEQ_OPTS_PRINT("%s", token2str(m->token));
1980         }
1981
1982         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1983             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1984                 SEQ_OPTS_PRINT("resuid=%u",
1985                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
1986         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1987             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1988                 SEQ_OPTS_PRINT("resgid=%u",
1989                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
1990         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1991         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1992                 SEQ_OPTS_PUTS("errors=remount-ro");
1993         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1994                 SEQ_OPTS_PUTS("errors=continue");
1995         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1996                 SEQ_OPTS_PUTS("errors=panic");
1997         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1998                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1999         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2000                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2001         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2002                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2003         if (sb->s_flags & MS_I_VERSION)
2004                 SEQ_OPTS_PUTS("i_version");
2005         if (nodefs || sbi->s_stripe)
2006                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2007         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2008                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2009                         SEQ_OPTS_PUTS("data=journal");
2010                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2011                         SEQ_OPTS_PUTS("data=ordered");
2012                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2013                         SEQ_OPTS_PUTS("data=writeback");
2014         }
2015         if (nodefs ||
2016             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2017                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2018                                sbi->s_inode_readahead_blks);
2019
2020         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2021                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2022                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2023         if (nodefs || sbi->s_max_dir_size_kb)
2024                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2025         if (test_opt(sb, DATA_ERR_ABORT))
2026                 SEQ_OPTS_PUTS("data_err=abort");
2027
2028         ext4_show_quota_options(seq, sb);
2029         return 0;
2030 }
2031
2032 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2033 {
2034         return _ext4_show_options(seq, root->d_sb, 0);
2035 }
2036
2037 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2038 {
2039         struct super_block *sb = seq->private;
2040         int rc;
2041
2042         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2043         rc = _ext4_show_options(seq, sb, 1);
2044         seq_puts(seq, "\n");
2045         return rc;
2046 }
2047
2048 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2049                             int read_only)
2050 {
2051         struct ext4_sb_info *sbi = EXT4_SB(sb);
2052         int res = 0;
2053
2054         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2055                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2056                          "forcing read-only mode");
2057                 res = MS_RDONLY;
2058         }
2059         if (read_only)
2060                 goto done;
2061         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2062                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2063                          "running e2fsck is recommended");
2064         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2065                 ext4_msg(sb, KERN_WARNING,
2066                          "warning: mounting fs with errors, "
2067                          "running e2fsck is recommended");
2068         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2069                  le16_to_cpu(es->s_mnt_count) >=
2070                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2071                 ext4_msg(sb, KERN_WARNING,
2072                          "warning: maximal mount count reached, "
2073                          "running e2fsck is recommended");
2074         else if (le32_to_cpu(es->s_checkinterval) &&
2075                 (le32_to_cpu(es->s_lastcheck) +
2076                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2077                 ext4_msg(sb, KERN_WARNING,
2078                          "warning: checktime reached, "
2079                          "running e2fsck is recommended");
2080         if (!sbi->s_journal)
2081                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2082         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2083                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2084         le16_add_cpu(&es->s_mnt_count, 1);
2085         es->s_mtime = cpu_to_le32(get_seconds());
2086         ext4_update_dynamic_rev(sb);
2087         if (sbi->s_journal)
2088                 ext4_set_feature_journal_needs_recovery(sb);
2089
2090         ext4_commit_super(sb, 1);
2091 done:
2092         if (test_opt(sb, DEBUG))
2093                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2094                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2095                         sb->s_blocksize,
2096                         sbi->s_groups_count,
2097                         EXT4_BLOCKS_PER_GROUP(sb),
2098                         EXT4_INODES_PER_GROUP(sb),
2099                         sbi->s_mount_opt, sbi->s_mount_opt2);
2100
2101         cleancache_init_fs(sb);
2102         return res;
2103 }
2104
2105 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2106 {
2107         struct ext4_sb_info *sbi = EXT4_SB(sb);
2108         struct flex_groups *new_groups;
2109         int size;
2110
2111         if (!sbi->s_log_groups_per_flex)
2112                 return 0;
2113
2114         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2115         if (size <= sbi->s_flex_groups_allocated)
2116                 return 0;
2117
2118         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2119         new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2120         if (!new_groups) {
2121                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2122                          size / (int) sizeof(struct flex_groups));
2123                 return -ENOMEM;
2124         }
2125
2126         if (sbi->s_flex_groups) {
2127                 memcpy(new_groups, sbi->s_flex_groups,
2128                        (sbi->s_flex_groups_allocated *
2129                         sizeof(struct flex_groups)));
2130                 kvfree(sbi->s_flex_groups);
2131         }
2132         sbi->s_flex_groups = new_groups;
2133         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2134         return 0;
2135 }
2136
2137 static int ext4_fill_flex_info(struct super_block *sb)
2138 {
2139         struct ext4_sb_info *sbi = EXT4_SB(sb);
2140         struct ext4_group_desc *gdp = NULL;
2141         ext4_group_t flex_group;
2142         int i, err;
2143
2144         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2145         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2146                 sbi->s_log_groups_per_flex = 0;
2147                 return 1;
2148         }
2149
2150         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2151         if (err)
2152                 goto failed;
2153
2154         for (i = 0; i < sbi->s_groups_count; i++) {
2155                 gdp = ext4_get_group_desc(sb, i, NULL);
2156
2157                 flex_group = ext4_flex_group(sbi, i);
2158                 atomic_add(ext4_free_inodes_count(sb, gdp),
2159                            &sbi->s_flex_groups[flex_group].free_inodes);
2160                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2161                              &sbi->s_flex_groups[flex_group].free_clusters);
2162                 atomic_add(ext4_used_dirs_count(sb, gdp),
2163                            &sbi->s_flex_groups[flex_group].used_dirs);
2164         }
2165
2166         return 1;
2167 failed:
2168         return 0;
2169 }
2170
2171 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2172                                    struct ext4_group_desc *gdp)
2173 {
2174         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2175         __u16 crc = 0;
2176         __le32 le_group = cpu_to_le32(block_group);
2177         struct ext4_sb_info *sbi = EXT4_SB(sb);
2178
2179         if (ext4_has_metadata_csum(sbi->s_sb)) {
2180                 /* Use new metadata_csum algorithm */
2181                 __u32 csum32;
2182                 __u16 dummy_csum = 0;
2183
2184                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2185                                      sizeof(le_group));
2186                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2187                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2188                                      sizeof(dummy_csum));
2189                 offset += sizeof(dummy_csum);
2190                 if (offset < sbi->s_desc_size)
2191                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2192                                              sbi->s_desc_size - offset);
2193
2194                 crc = csum32 & 0xFFFF;
2195                 goto out;
2196         }
2197
2198         /* old crc16 code */
2199         if (!ext4_has_feature_gdt_csum(sb))
2200                 return 0;
2201
2202         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2203         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2204         crc = crc16(crc, (__u8 *)gdp, offset);
2205         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2206         /* for checksum of struct ext4_group_desc do the rest...*/
2207         if (ext4_has_feature_64bit(sb) &&
2208             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2209                 crc = crc16(crc, (__u8 *)gdp + offset,
2210                             le16_to_cpu(sbi->s_es->s_desc_size) -
2211                                 offset);
2212
2213 out:
2214         return cpu_to_le16(crc);
2215 }
2216
2217 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2218                                 struct ext4_group_desc *gdp)
2219 {
2220         if (ext4_has_group_desc_csum(sb) &&
2221             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2222                 return 0;
2223
2224         return 1;
2225 }
2226
2227 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2228                               struct ext4_group_desc *gdp)
2229 {
2230         if (!ext4_has_group_desc_csum(sb))
2231                 return;
2232         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2233 }
2234
2235 /* Called at mount-time, super-block is locked */
2236 static int ext4_check_descriptors(struct super_block *sb,
2237                                   ext4_fsblk_t sb_block,
2238                                   ext4_group_t *first_not_zeroed)
2239 {
2240         struct ext4_sb_info *sbi = EXT4_SB(sb);
2241         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2242         ext4_fsblk_t last_block;
2243         ext4_fsblk_t block_bitmap;
2244         ext4_fsblk_t inode_bitmap;
2245         ext4_fsblk_t inode_table;
2246         int flexbg_flag = 0;
2247         ext4_group_t i, grp = sbi->s_groups_count;
2248
2249         if (ext4_has_feature_flex_bg(sb))
2250                 flexbg_flag = 1;
2251
2252         ext4_debug("Checking group descriptors");
2253
2254         for (i = 0; i < sbi->s_groups_count; i++) {
2255                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2256
2257                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2258                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2259                 else
2260                         last_block = first_block +
2261                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2262
2263                 if ((grp == sbi->s_groups_count) &&
2264                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2265                         grp = i;
2266
2267                 block_bitmap = ext4_block_bitmap(sb, gdp);
2268                 if (block_bitmap == sb_block) {
2269                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2270                                  "Block bitmap for group %u overlaps "
2271                                  "superblock", i);
2272                 }
2273                 if (block_bitmap < first_block || block_bitmap > last_block) {
2274                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2275                                "Block bitmap for group %u not in group "
2276                                "(block %llu)!", i, block_bitmap);
2277                         return 0;
2278                 }
2279                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2280                 if (inode_bitmap == sb_block) {
2281                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2282                                  "Inode bitmap for group %u overlaps "
2283                                  "superblock", i);
2284                 }
2285                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2286                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2287                                "Inode bitmap for group %u not in group "
2288                                "(block %llu)!", i, inode_bitmap);
2289                         return 0;
2290                 }
2291                 inode_table = ext4_inode_table(sb, gdp);
2292                 if (inode_table == sb_block) {
2293                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2294                                  "Inode table for group %u overlaps "
2295                                  "superblock", i);
2296                 }
2297                 if (inode_table < first_block ||
2298                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2299                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2300                                "Inode table for group %u not in group "
2301                                "(block %llu)!", i, inode_table);
2302                         return 0;
2303                 }
2304                 ext4_lock_group(sb, i);
2305                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2306                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2307                                  "Checksum for group %u failed (%u!=%u)",
2308                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2309                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2310                         if (!(sb->s_flags & MS_RDONLY)) {
2311                                 ext4_unlock_group(sb, i);
2312                                 return 0;
2313                         }
2314                 }
2315                 ext4_unlock_group(sb, i);
2316                 if (!flexbg_flag)
2317                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2318         }
2319         if (NULL != first_not_zeroed)
2320                 *first_not_zeroed = grp;
2321         return 1;
2322 }
2323
2324 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2325  * the superblock) which were deleted from all directories, but held open by
2326  * a process at the time of a crash.  We walk the list and try to delete these
2327  * inodes at recovery time (only with a read-write filesystem).
2328  *
2329  * In order to keep the orphan inode chain consistent during traversal (in
2330  * case of crash during recovery), we link each inode into the superblock
2331  * orphan list_head and handle it the same way as an inode deletion during
2332  * normal operation (which journals the operations for us).
2333  *
2334  * We only do an iget() and an iput() on each inode, which is very safe if we
2335  * accidentally point at an in-use or already deleted inode.  The worst that
2336  * can happen in this case is that we get a "bit already cleared" message from
2337  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2338  * e2fsck was run on this filesystem, and it must have already done the orphan
2339  * inode cleanup for us, so we can safely abort without any further action.
2340  */
2341 static void ext4_orphan_cleanup(struct super_block *sb,
2342                                 struct ext4_super_block *es)
2343 {
2344         unsigned int s_flags = sb->s_flags;
2345         int ret, nr_orphans = 0, nr_truncates = 0;
2346 #ifdef CONFIG_QUOTA
2347         int i;
2348 #endif
2349         if (!es->s_last_orphan) {
2350                 jbd_debug(4, "no orphan inodes to clean up\n");
2351                 return;
2352         }
2353
2354         if (bdev_read_only(sb->s_bdev)) {
2355                 ext4_msg(sb, KERN_ERR, "write access "
2356                         "unavailable, skipping orphan cleanup");
2357                 return;
2358         }
2359
2360         /* Check if feature set would not allow a r/w mount */
2361         if (!ext4_feature_set_ok(sb, 0)) {
2362                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2363                          "unknown ROCOMPAT features");
2364                 return;
2365         }
2366
2367         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2368                 /* don't clear list on RO mount w/ errors */
2369                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2370                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2371                                   "clearing orphan list.\n");
2372                         es->s_last_orphan = 0;
2373                 }
2374                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2375                 return;
2376         }
2377
2378         if (s_flags & MS_RDONLY) {
2379                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2380                 sb->s_flags &= ~MS_RDONLY;
2381         }
2382 #ifdef CONFIG_QUOTA
2383         /* Needed for iput() to work correctly and not trash data */
2384         sb->s_flags |= MS_ACTIVE;
2385         /* Turn on quotas so that they are updated correctly */
2386         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2387                 if (EXT4_SB(sb)->s_qf_names[i]) {
2388                         int ret = ext4_quota_on_mount(sb, i);
2389                         if (ret < 0)
2390                                 ext4_msg(sb, KERN_ERR,
2391                                         "Cannot turn on journaled "
2392                                         "quota: error %d", ret);
2393                 }
2394         }
2395 #endif
2396
2397         while (es->s_last_orphan) {
2398                 struct inode *inode;
2399
2400                 /*
2401                  * We may have encountered an error during cleanup; if
2402                  * so, skip the rest.
2403                  */
2404                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2405                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2406                         es->s_last_orphan = 0;
2407                         break;
2408                 }
2409
2410                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2411                 if (IS_ERR(inode)) {
2412                         es->s_last_orphan = 0;
2413                         break;
2414                 }
2415
2416                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2417                 dquot_initialize(inode);
2418                 if (inode->i_nlink) {
2419                         if (test_opt(sb, DEBUG))
2420                                 ext4_msg(sb, KERN_DEBUG,
2421                                         "%s: truncating inode %lu to %lld bytes",
2422                                         __func__, inode->i_ino, inode->i_size);
2423                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2424                                   inode->i_ino, inode->i_size);
2425                         inode_lock(inode);
2426                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2427                         ret = ext4_truncate(inode);
2428                         if (ret)
2429                                 ext4_std_error(inode->i_sb, ret);
2430                         inode_unlock(inode);
2431                         nr_truncates++;
2432                 } else {
2433                         if (test_opt(sb, DEBUG))
2434                                 ext4_msg(sb, KERN_DEBUG,
2435                                         "%s: deleting unreferenced inode %lu",
2436                                         __func__, inode->i_ino);
2437                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2438                                   inode->i_ino);
2439                         nr_orphans++;
2440                 }
2441                 iput(inode);  /* The delete magic happens here! */
2442         }
2443
2444 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2445
2446         if (nr_orphans)
2447                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2448                        PLURAL(nr_orphans));
2449         if (nr_truncates)
2450                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2451                        PLURAL(nr_truncates));
2452 #ifdef CONFIG_QUOTA
2453         /* Turn quotas off */
2454         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2455                 if (sb_dqopt(sb)->files[i])
2456                         dquot_quota_off(sb, i);
2457         }
2458 #endif
2459         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2460 }
2461
2462 /*
2463  * Maximal extent format file size.
2464  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2465  * extent format containers, within a sector_t, and within i_blocks
2466  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2467  * so that won't be a limiting factor.
2468  *
2469  * However there is other limiting factor. We do store extents in the form
2470  * of starting block and length, hence the resulting length of the extent
2471  * covering maximum file size must fit into on-disk format containers as
2472  * well. Given that length is always by 1 unit bigger than max unit (because
2473  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2474  *
2475  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2476  */
2477 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2478 {
2479         loff_t res;
2480         loff_t upper_limit = MAX_LFS_FILESIZE;
2481
2482         /* small i_blocks in vfs inode? */
2483         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2484                 /*
2485                  * CONFIG_LBDAF is not enabled implies the inode
2486                  * i_block represent total blocks in 512 bytes
2487                  * 32 == size of vfs inode i_blocks * 8
2488                  */
2489                 upper_limit = (1LL << 32) - 1;
2490
2491                 /* total blocks in file system block size */
2492                 upper_limit >>= (blkbits - 9);
2493                 upper_limit <<= blkbits;
2494         }
2495
2496         /*
2497          * 32-bit extent-start container, ee_block. We lower the maxbytes
2498          * by one fs block, so ee_len can cover the extent of maximum file
2499          * size
2500          */
2501         res = (1LL << 32) - 1;
2502         res <<= blkbits;
2503
2504         /* Sanity check against vm- & vfs- imposed limits */
2505         if (res > upper_limit)
2506                 res = upper_limit;
2507
2508         return res;
2509 }
2510
2511 /*
2512  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2513  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2514  * We need to be 1 filesystem block less than the 2^48 sector limit.
2515  */
2516 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2517 {
2518         loff_t res = EXT4_NDIR_BLOCKS;
2519         int meta_blocks;
2520         loff_t upper_limit;
2521         /* This is calculated to be the largest file size for a dense, block
2522          * mapped file such that the file's total number of 512-byte sectors,
2523          * including data and all indirect blocks, does not exceed (2^48 - 1).
2524          *
2525          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2526          * number of 512-byte sectors of the file.
2527          */
2528
2529         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2530                 /*
2531                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2532                  * the inode i_block field represents total file blocks in
2533                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2534                  */
2535                 upper_limit = (1LL << 32) - 1;
2536
2537                 /* total blocks in file system block size */
2538                 upper_limit >>= (bits - 9);
2539
2540         } else {
2541                 /*
2542                  * We use 48 bit ext4_inode i_blocks
2543                  * With EXT4_HUGE_FILE_FL set the i_blocks
2544                  * represent total number of blocks in
2545                  * file system block size
2546                  */
2547                 upper_limit = (1LL << 48) - 1;
2548
2549         }
2550
2551         /* indirect blocks */
2552         meta_blocks = 1;
2553         /* double indirect blocks */
2554         meta_blocks += 1 + (1LL << (bits-2));
2555         /* tripple indirect blocks */
2556         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2557
2558         upper_limit -= meta_blocks;
2559         upper_limit <<= bits;
2560
2561         res += 1LL << (bits-2);
2562         res += 1LL << (2*(bits-2));
2563         res += 1LL << (3*(bits-2));
2564         res <<= bits;
2565         if (res > upper_limit)
2566                 res = upper_limit;
2567
2568         if (res > MAX_LFS_FILESIZE)
2569                 res = MAX_LFS_FILESIZE;
2570
2571         return res;
2572 }
2573
2574 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2575                                    ext4_fsblk_t logical_sb_block, int nr)
2576 {
2577         struct ext4_sb_info *sbi = EXT4_SB(sb);
2578         ext4_group_t bg, first_meta_bg;
2579         int has_super = 0;
2580
2581         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2582
2583         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2584                 return logical_sb_block + nr + 1;
2585         bg = sbi->s_desc_per_block * nr;
2586         if (ext4_bg_has_super(sb, bg))
2587                 has_super = 1;
2588
2589         /*
2590          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2591          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2592          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2593          * compensate.
2594          */
2595         if (sb->s_blocksize == 1024 && nr == 0 &&
2596             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2597                 has_super++;
2598
2599         return (has_super + ext4_group_first_block_no(sb, bg));
2600 }
2601
2602 /**
2603  * ext4_get_stripe_size: Get the stripe size.
2604  * @sbi: In memory super block info
2605  *
2606  * If we have specified it via mount option, then
2607  * use the mount option value. If the value specified at mount time is
2608  * greater than the blocks per group use the super block value.
2609  * If the super block value is greater than blocks per group return 0.
2610  * Allocator needs it be less than blocks per group.
2611  *
2612  */
2613 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2614 {
2615         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2616         unsigned long stripe_width =
2617                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2618         int ret;
2619
2620         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2621                 ret = sbi->s_stripe;
2622         else if (stripe_width <= sbi->s_blocks_per_group)
2623                 ret = stripe_width;
2624         else if (stride <= sbi->s_blocks_per_group)
2625                 ret = stride;
2626         else
2627                 ret = 0;
2628
2629         /*
2630          * If the stripe width is 1, this makes no sense and
2631          * we set it to 0 to turn off stripe handling code.
2632          */
2633         if (ret <= 1)
2634                 ret = 0;
2635
2636         return ret;
2637 }
2638
2639 /*
2640  * Check whether this filesystem can be mounted based on
2641  * the features present and the RDONLY/RDWR mount requested.
2642  * Returns 1 if this filesystem can be mounted as requested,
2643  * 0 if it cannot be.
2644  */
2645 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2646 {
2647         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2648                 ext4_msg(sb, KERN_ERR,
2649                         "Couldn't mount because of "
2650                         "unsupported optional features (%x)",
2651                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2652                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2653                 return 0;
2654         }
2655
2656         if (readonly)
2657                 return 1;
2658
2659         if (ext4_has_feature_readonly(sb)) {
2660                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2661                 sb->s_flags |= MS_RDONLY;
2662                 return 1;
2663         }
2664
2665         /* Check that feature set is OK for a read-write mount */
2666         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2667                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2668                          "unsupported optional features (%x)",
2669                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2670                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2671                 return 0;
2672         }
2673         /*
2674          * Large file size enabled file system can only be mounted
2675          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2676          */
2677         if (ext4_has_feature_huge_file(sb)) {
2678                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2679                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2680                                  "cannot be mounted RDWR without "
2681                                  "CONFIG_LBDAF");
2682                         return 0;
2683                 }
2684         }
2685         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2686                 ext4_msg(sb, KERN_ERR,
2687                          "Can't support bigalloc feature without "
2688                          "extents feature\n");
2689                 return 0;
2690         }
2691
2692 #ifndef CONFIG_QUOTA
2693         if (ext4_has_feature_quota(sb) && !readonly) {
2694                 ext4_msg(sb, KERN_ERR,
2695                          "Filesystem with quota feature cannot be mounted RDWR "
2696                          "without CONFIG_QUOTA");
2697                 return 0;
2698         }
2699         if (ext4_has_feature_project(sb) && !readonly) {
2700                 ext4_msg(sb, KERN_ERR,
2701                          "Filesystem with project quota feature cannot be mounted RDWR "
2702                          "without CONFIG_QUOTA");
2703                 return 0;
2704         }
2705 #endif  /* CONFIG_QUOTA */
2706         return 1;
2707 }
2708
2709 /*
2710  * This function is called once a day if we have errors logged
2711  * on the file system
2712  */
2713 static void print_daily_error_info(unsigned long arg)
2714 {
2715         struct super_block *sb = (struct super_block *) arg;
2716         struct ext4_sb_info *sbi;
2717         struct ext4_super_block *es;
2718
2719         sbi = EXT4_SB(sb);
2720         es = sbi->s_es;
2721
2722         if (es->s_error_count)
2723                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2724                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2725                          le32_to_cpu(es->s_error_count));
2726         if (es->s_first_error_time) {
2727                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2728                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2729                        (int) sizeof(es->s_first_error_func),
2730                        es->s_first_error_func,
2731                        le32_to_cpu(es->s_first_error_line));
2732                 if (es->s_first_error_ino)
2733                         printk(KERN_CONT ": inode %u",
2734                                le32_to_cpu(es->s_first_error_ino));
2735                 if (es->s_first_error_block)
2736                         printk(KERN_CONT ": block %llu", (unsigned long long)
2737                                le64_to_cpu(es->s_first_error_block));
2738                 printk(KERN_CONT "\n");
2739         }
2740         if (es->s_last_error_time) {
2741                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2742                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2743                        (int) sizeof(es->s_last_error_func),
2744                        es->s_last_error_func,
2745                        le32_to_cpu(es->s_last_error_line));
2746                 if (es->s_last_error_ino)
2747                         printk(KERN_CONT ": inode %u",
2748                                le32_to_cpu(es->s_last_error_ino));
2749                 if (es->s_last_error_block)
2750                         printk(KERN_CONT ": block %llu", (unsigned long long)
2751                                le64_to_cpu(es->s_last_error_block));
2752                 printk(KERN_CONT "\n");
2753         }
2754         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2755 }
2756
2757 /* Find next suitable group and run ext4_init_inode_table */
2758 static int ext4_run_li_request(struct ext4_li_request *elr)
2759 {
2760         struct ext4_group_desc *gdp = NULL;
2761         ext4_group_t group, ngroups;
2762         struct super_block *sb;
2763         unsigned long timeout = 0;
2764         int ret = 0;
2765
2766         sb = elr->lr_super;
2767         ngroups = EXT4_SB(sb)->s_groups_count;
2768
2769         for (group = elr->lr_next_group; group < ngroups; group++) {
2770                 gdp = ext4_get_group_desc(sb, group, NULL);
2771                 if (!gdp) {
2772                         ret = 1;
2773                         break;
2774                 }
2775
2776                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2777                         break;
2778         }
2779
2780         if (group >= ngroups)
2781                 ret = 1;
2782
2783         if (!ret) {
2784                 timeout = jiffies;
2785                 ret = ext4_init_inode_table(sb, group,
2786                                             elr->lr_timeout ? 0 : 1);
2787                 if (elr->lr_timeout == 0) {
2788                         timeout = (jiffies - timeout) *
2789                                   elr->lr_sbi->s_li_wait_mult;
2790                         elr->lr_timeout = timeout;
2791                 }
2792                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2793                 elr->lr_next_group = group + 1;
2794         }
2795         return ret;
2796 }
2797
2798 /*
2799  * Remove lr_request from the list_request and free the
2800  * request structure. Should be called with li_list_mtx held
2801  */
2802 static void ext4_remove_li_request(struct ext4_li_request *elr)
2803 {
2804         struct ext4_sb_info *sbi;
2805
2806         if (!elr)
2807                 return;
2808
2809         sbi = elr->lr_sbi;
2810
2811         list_del(&elr->lr_request);
2812         sbi->s_li_request = NULL;
2813         kfree(elr);
2814 }
2815
2816 static void ext4_unregister_li_request(struct super_block *sb)
2817 {
2818         mutex_lock(&ext4_li_mtx);
2819         if (!ext4_li_info) {
2820                 mutex_unlock(&ext4_li_mtx);
2821                 return;
2822         }
2823
2824         mutex_lock(&ext4_li_info->li_list_mtx);
2825         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2826         mutex_unlock(&ext4_li_info->li_list_mtx);
2827         mutex_unlock(&ext4_li_mtx);
2828 }
2829
2830 static struct task_struct *ext4_lazyinit_task;
2831
2832 /*
2833  * This is the function where ext4lazyinit thread lives. It walks
2834  * through the request list searching for next scheduled filesystem.
2835  * When such a fs is found, run the lazy initialization request
2836  * (ext4_rn_li_request) and keep track of the time spend in this
2837  * function. Based on that time we compute next schedule time of
2838  * the request. When walking through the list is complete, compute
2839  * next waking time and put itself into sleep.
2840  */
2841 static int ext4_lazyinit_thread(void *arg)
2842 {
2843         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2844         struct list_head *pos, *n;
2845         struct ext4_li_request *elr;
2846         unsigned long next_wakeup, cur;
2847
2848         BUG_ON(NULL == eli);
2849
2850 cont_thread:
2851         while (true) {
2852                 next_wakeup = MAX_JIFFY_OFFSET;
2853
2854                 mutex_lock(&eli->li_list_mtx);
2855                 if (list_empty(&eli->li_request_list)) {
2856                         mutex_unlock(&eli->li_list_mtx);
2857                         goto exit_thread;
2858                 }
2859                 list_for_each_safe(pos, n, &eli->li_request_list) {
2860                         int err = 0;
2861                         int progress = 0;
2862                         elr = list_entry(pos, struct ext4_li_request,
2863                                          lr_request);
2864
2865                         if (time_before(jiffies, elr->lr_next_sched)) {
2866                                 if (time_before(elr->lr_next_sched, next_wakeup))
2867                                         next_wakeup = elr->lr_next_sched;
2868                                 continue;
2869                         }
2870                         if (down_read_trylock(&elr->lr_super->s_umount)) {
2871                                 if (sb_start_write_trylock(elr->lr_super)) {
2872                                         progress = 1;
2873                                         /*
2874                                          * We hold sb->s_umount, sb can not
2875                                          * be removed from the list, it is
2876                                          * now safe to drop li_list_mtx
2877                                          */
2878                                         mutex_unlock(&eli->li_list_mtx);
2879                                         err = ext4_run_li_request(elr);
2880                                         sb_end_write(elr->lr_super);
2881                                         mutex_lock(&eli->li_list_mtx);
2882                                         n = pos->next;
2883                                 }
2884                                 up_read((&elr->lr_super->s_umount));
2885                         }
2886                         /* error, remove the lazy_init job */
2887                         if (err) {
2888                                 ext4_remove_li_request(elr);
2889                                 continue;
2890                         }
2891                         if (!progress) {
2892                                 elr->lr_next_sched = jiffies +
2893                                         (prandom_u32()
2894                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2895                         }
2896                         if (time_before(elr->lr_next_sched, next_wakeup))
2897                                 next_wakeup = elr->lr_next_sched;
2898                 }
2899                 mutex_unlock(&eli->li_list_mtx);
2900
2901                 try_to_freeze();
2902
2903                 cur = jiffies;
2904                 if ((time_after_eq(cur, next_wakeup)) ||
2905                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2906                         cond_resched();
2907                         continue;
2908                 }
2909
2910                 schedule_timeout_interruptible(next_wakeup - cur);
2911
2912                 if (kthread_should_stop()) {
2913                         ext4_clear_request_list();
2914                         goto exit_thread;
2915                 }
2916         }
2917
2918 exit_thread:
2919         /*
2920          * It looks like the request list is empty, but we need
2921          * to check it under the li_list_mtx lock, to prevent any
2922          * additions into it, and of course we should lock ext4_li_mtx
2923          * to atomically free the list and ext4_li_info, because at
2924          * this point another ext4 filesystem could be registering
2925          * new one.
2926          */
2927         mutex_lock(&ext4_li_mtx);
2928         mutex_lock(&eli->li_list_mtx);
2929         if (!list_empty(&eli->li_request_list)) {
2930                 mutex_unlock(&eli->li_list_mtx);
2931                 mutex_unlock(&ext4_li_mtx);
2932                 goto cont_thread;
2933         }
2934         mutex_unlock(&eli->li_list_mtx);
2935         kfree(ext4_li_info);
2936         ext4_li_info = NULL;
2937         mutex_unlock(&ext4_li_mtx);
2938
2939         return 0;
2940 }
2941
2942 static void ext4_clear_request_list(void)
2943 {
2944         struct list_head *pos, *n;
2945         struct ext4_li_request *elr;
2946
2947         mutex_lock(&ext4_li_info->li_list_mtx);
2948         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2949                 elr = list_entry(pos, struct ext4_li_request,
2950                                  lr_request);
2951                 ext4_remove_li_request(elr);
2952         }
2953         mutex_unlock(&ext4_li_info->li_list_mtx);
2954 }
2955
2956 static int ext4_run_lazyinit_thread(void)
2957 {
2958         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2959                                          ext4_li_info, "ext4lazyinit");
2960         if (IS_ERR(ext4_lazyinit_task)) {
2961                 int err = PTR_ERR(ext4_lazyinit_task);
2962                 ext4_clear_request_list();
2963                 kfree(ext4_li_info);
2964                 ext4_li_info = NULL;
2965                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2966                                  "initialization thread\n",
2967                                  err);
2968                 return err;
2969         }
2970         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2971         return 0;
2972 }
2973
2974 /*
2975  * Check whether it make sense to run itable init. thread or not.
2976  * If there is at least one uninitialized inode table, return
2977  * corresponding group number, else the loop goes through all
2978  * groups and return total number of groups.
2979  */
2980 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2981 {
2982         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2983         struct ext4_group_desc *gdp = NULL;
2984
2985         for (group = 0; group < ngroups; group++) {
2986                 gdp = ext4_get_group_desc(sb, group, NULL);
2987                 if (!gdp)
2988                         continue;
2989
2990                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2991                         break;
2992         }
2993
2994         return group;
2995 }
2996
2997 static int ext4_li_info_new(void)
2998 {
2999         struct ext4_lazy_init *eli = NULL;
3000
3001         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3002         if (!eli)
3003                 return -ENOMEM;
3004
3005         INIT_LIST_HEAD(&eli->li_request_list);
3006         mutex_init(&eli->li_list_mtx);
3007
3008         eli->li_state |= EXT4_LAZYINIT_QUIT;
3009
3010         ext4_li_info = eli;
3011
3012         return 0;
3013 }
3014
3015 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3016                                             ext4_group_t start)
3017 {
3018         struct ext4_sb_info *sbi = EXT4_SB(sb);
3019         struct ext4_li_request *elr;
3020
3021         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3022         if (!elr)
3023                 return NULL;
3024
3025         elr->lr_super = sb;
3026         elr->lr_sbi = sbi;
3027         elr->lr_next_group = start;
3028
3029         /*
3030          * Randomize first schedule time of the request to
3031          * spread the inode table initialization requests
3032          * better.
3033          */
3034         elr->lr_next_sched = jiffies + (prandom_u32() %
3035                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3036         return elr;
3037 }
3038
3039 int ext4_register_li_request(struct super_block *sb,
3040                              ext4_group_t first_not_zeroed)
3041 {
3042         struct ext4_sb_info *sbi = EXT4_SB(sb);
3043         struct ext4_li_request *elr = NULL;
3044         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3045         int ret = 0;
3046
3047         mutex_lock(&ext4_li_mtx);
3048         if (sbi->s_li_request != NULL) {
3049                 /*
3050                  * Reset timeout so it can be computed again, because
3051                  * s_li_wait_mult might have changed.
3052                  */
3053                 sbi->s_li_request->lr_timeout = 0;
3054                 goto out;
3055         }
3056
3057         if (first_not_zeroed == ngroups ||
3058             (sb->s_flags & MS_RDONLY) ||
3059             !test_opt(sb, INIT_INODE_TABLE))
3060                 goto out;
3061
3062         elr = ext4_li_request_new(sb, first_not_zeroed);
3063         if (!elr) {
3064                 ret = -ENOMEM;
3065                 goto out;
3066         }
3067
3068         if (NULL == ext4_li_info) {
3069                 ret = ext4_li_info_new();
3070                 if (ret)
3071                         goto out;
3072         }
3073
3074         mutex_lock(&ext4_li_info->li_list_mtx);
3075         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3076         mutex_unlock(&ext4_li_info->li_list_mtx);
3077
3078         sbi->s_li_request = elr;
3079         /*
3080          * set elr to NULL here since it has been inserted to
3081          * the request_list and the removal and free of it is
3082          * handled by ext4_clear_request_list from now on.
3083          */
3084         elr = NULL;
3085
3086         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3087                 ret = ext4_run_lazyinit_thread();
3088                 if (ret)
3089                         goto out;
3090         }
3091 out:
3092         mutex_unlock(&ext4_li_mtx);
3093         if (ret)
3094                 kfree(elr);
3095         return ret;
3096 }
3097
3098 /*
3099  * We do not need to lock anything since this is called on
3100  * module unload.
3101  */
3102 static void ext4_destroy_lazyinit_thread(void)
3103 {
3104         /*
3105          * If thread exited earlier
3106          * there's nothing to be done.
3107          */
3108         if (!ext4_li_info || !ext4_lazyinit_task)
3109                 return;
3110
3111         kthread_stop(ext4_lazyinit_task);
3112 }
3113
3114 static int set_journal_csum_feature_set(struct super_block *sb)
3115 {
3116         int ret = 1;
3117         int compat, incompat;
3118         struct ext4_sb_info *sbi = EXT4_SB(sb);
3119
3120         if (ext4_has_metadata_csum(sb)) {
3121                 /* journal checksum v3 */
3122                 compat = 0;
3123                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3124         } else {
3125                 /* journal checksum v1 */
3126                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3127                 incompat = 0;
3128         }
3129
3130         jbd2_journal_clear_features(sbi->s_journal,
3131                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3132                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3133                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3134         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3135                 ret = jbd2_journal_set_features(sbi->s_journal,
3136                                 compat, 0,
3137                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3138                                 incompat);
3139         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3140                 ret = jbd2_journal_set_features(sbi->s_journal,
3141                                 compat, 0,
3142                                 incompat);
3143                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3144                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3145         } else {
3146                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3147                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3148         }
3149
3150         return ret;
3151 }
3152
3153 /*
3154  * Note: calculating the overhead so we can be compatible with
3155  * historical BSD practice is quite difficult in the face of
3156  * clusters/bigalloc.  This is because multiple metadata blocks from
3157  * different block group can end up in the same allocation cluster.
3158  * Calculating the exact overhead in the face of clustered allocation
3159  * requires either O(all block bitmaps) in memory or O(number of block
3160  * groups**2) in time.  We will still calculate the superblock for
3161  * older file systems --- and if we come across with a bigalloc file
3162  * system with zero in s_overhead_clusters the estimate will be close to
3163  * correct especially for very large cluster sizes --- but for newer
3164  * file systems, it's better to calculate this figure once at mkfs
3165  * time, and store it in the superblock.  If the superblock value is
3166  * present (even for non-bigalloc file systems), we will use it.
3167  */
3168 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3169                           char *buf)
3170 {
3171         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3172         struct ext4_group_desc  *gdp;
3173         ext4_fsblk_t            first_block, last_block, b;
3174         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3175         int                     s, j, count = 0;
3176
3177         if (!ext4_has_feature_bigalloc(sb))
3178                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3179                         sbi->s_itb_per_group + 2);
3180
3181         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3182                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3183         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3184         for (i = 0; i < ngroups; i++) {
3185                 gdp = ext4_get_group_desc(sb, i, NULL);
3186                 b = ext4_block_bitmap(sb, gdp);
3187                 if (b >= first_block && b <= last_block) {
3188                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3189                         count++;
3190                 }
3191                 b = ext4_inode_bitmap(sb, gdp);
3192                 if (b >= first_block && b <= last_block) {
3193                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3194                         count++;
3195                 }
3196                 b = ext4_inode_table(sb, gdp);
3197                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3198                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3199                                 int c = EXT4_B2C(sbi, b - first_block);
3200                                 ext4_set_bit(c, buf);
3201                                 count++;
3202                         }
3203                 if (i != grp)
3204                         continue;
3205                 s = 0;
3206                 if (ext4_bg_has_super(sb, grp)) {
3207                         ext4_set_bit(s++, buf);
3208                         count++;
3209                 }
3210                 j = ext4_bg_num_gdb(sb, grp);
3211                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3212                         ext4_error(sb, "Invalid number of block group "
3213                                    "descriptor blocks: %d", j);
3214                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3215                 }
3216                 count += j;
3217                 for (; j > 0; j--)
3218                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3219         }
3220         if (!count)
3221                 return 0;
3222         return EXT4_CLUSTERS_PER_GROUP(sb) -
3223                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3224 }
3225
3226 /*
3227  * Compute the overhead and stash it in sbi->s_overhead
3228  */
3229 int ext4_calculate_overhead(struct super_block *sb)
3230 {
3231         struct ext4_sb_info *sbi = EXT4_SB(sb);
3232         struct ext4_super_block *es = sbi->s_es;
3233         struct inode *j_inode;
3234         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3235         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3236         ext4_fsblk_t overhead = 0;
3237         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3238
3239         if (!buf)
3240                 return -ENOMEM;
3241
3242         /*
3243          * Compute the overhead (FS structures).  This is constant
3244          * for a given filesystem unless the number of block groups
3245          * changes so we cache the previous value until it does.
3246          */
3247
3248         /*
3249          * All of the blocks before first_data_block are overhead
3250          */
3251         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3252
3253         /*
3254          * Add the overhead found in each block group
3255          */
3256         for (i = 0; i < ngroups; i++) {
3257                 int blks;
3258
3259                 blks = count_overhead(sb, i, buf);
3260                 overhead += blks;
3261                 if (blks)
3262                         memset(buf, 0, PAGE_SIZE);
3263                 cond_resched();
3264         }
3265
3266         /*
3267          * Add the internal journal blocks whether the journal has been
3268          * loaded or not
3269          */
3270         if (sbi->s_journal && !sbi->journal_bdev)
3271                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3272         else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3273                 j_inode = ext4_get_journal_inode(sb, j_inum);
3274                 if (j_inode) {
3275                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3276                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
3277                         iput(j_inode);
3278                 } else {
3279                         ext4_msg(sb, KERN_ERR, "can't get journal size");
3280                 }
3281         }
3282         sbi->s_overhead = overhead;
3283         smp_wmb();
3284         free_page((unsigned long) buf);
3285         return 0;
3286 }
3287
3288 static void ext4_set_resv_clusters(struct super_block *sb)
3289 {
3290         ext4_fsblk_t resv_clusters;
3291         struct ext4_sb_info *sbi = EXT4_SB(sb);
3292
3293         /*
3294          * There's no need to reserve anything when we aren't using extents.
3295          * The space estimates are exact, there are no unwritten extents,
3296          * hole punching doesn't need new metadata... This is needed especially
3297          * to keep ext2/3 backward compatibility.
3298          */
3299         if (!ext4_has_feature_extents(sb))
3300                 return;
3301         /*
3302          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3303          * This should cover the situations where we can not afford to run
3304          * out of space like for example punch hole, or converting
3305          * unwritten extents in delalloc path. In most cases such
3306          * allocation would require 1, or 2 blocks, higher numbers are
3307          * very rare.
3308          */
3309         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3310                          sbi->s_cluster_bits);
3311
3312         do_div(resv_clusters, 50);
3313         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3314
3315         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3316 }
3317
3318 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3319 {
3320         char *orig_data = kstrdup(data, GFP_KERNEL);
3321         struct buffer_head *bh;
3322         struct ext4_super_block *es = NULL;
3323         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3324         ext4_fsblk_t block;
3325         ext4_fsblk_t sb_block = get_sb_block(&data);
3326         ext4_fsblk_t logical_sb_block;
3327         unsigned long offset = 0;
3328         unsigned long journal_devnum = 0;
3329         unsigned long def_mount_opts;
3330         struct inode *root;
3331         const char *descr;
3332         int ret = -ENOMEM;
3333         int blocksize, clustersize;
3334         unsigned int db_count;
3335         unsigned int i;
3336         int needs_recovery, has_huge_files, has_bigalloc;
3337         __u64 blocks_count;
3338         int err = 0;
3339         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3340         ext4_group_t first_not_zeroed;
3341
3342         if ((data && !orig_data) || !sbi)
3343                 goto out_free_base;
3344
3345         sbi->s_blockgroup_lock =
3346                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3347         if (!sbi->s_blockgroup_lock)
3348                 goto out_free_base;
3349
3350         sb->s_fs_info = sbi;
3351         sbi->s_sb = sb;
3352         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3353         sbi->s_sb_block = sb_block;
3354         if (sb->s_bdev->bd_part)
3355                 sbi->s_sectors_written_start =
3356                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3357
3358         /* Cleanup superblock name */
3359         strreplace(sb->s_id, '/', '!');
3360
3361         /* -EINVAL is default */
3362         ret = -EINVAL;
3363         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3364         if (!blocksize) {
3365                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3366                 goto out_fail;
3367         }
3368
3369         /*
3370          * The ext4 superblock will not be buffer aligned for other than 1kB
3371          * block sizes.  We need to calculate the offset from buffer start.
3372          */
3373         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3374                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3375                 offset = do_div(logical_sb_block, blocksize);
3376         } else {
3377                 logical_sb_block = sb_block;
3378         }
3379
3380         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3381                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3382                 goto out_fail;
3383         }
3384         /*
3385          * Note: s_es must be initialized as soon as possible because
3386          *       some ext4 macro-instructions depend on its value
3387          */
3388         es = (struct ext4_super_block *) (bh->b_data + offset);
3389         sbi->s_es = es;
3390         sb->s_magic = le16_to_cpu(es->s_magic);
3391         if (sb->s_magic != EXT4_SUPER_MAGIC)
3392                 goto cantfind_ext4;
3393         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3394
3395         /* Warn if metadata_csum and gdt_csum are both set. */
3396         if (ext4_has_feature_metadata_csum(sb) &&
3397             ext4_has_feature_gdt_csum(sb))
3398                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3399                              "redundant flags; please run fsck.");
3400
3401         /* Check for a known checksum algorithm */
3402         if (!ext4_verify_csum_type(sb, es)) {
3403                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3404                          "unknown checksum algorithm.");
3405                 silent = 1;
3406                 goto cantfind_ext4;
3407         }
3408
3409         /* Load the checksum driver */
3410         if (ext4_has_feature_metadata_csum(sb)) {
3411                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3412                 if (IS_ERR(sbi->s_chksum_driver)) {
3413                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3414                         ret = PTR_ERR(sbi->s_chksum_driver);
3415                         sbi->s_chksum_driver = NULL;
3416                         goto failed_mount;
3417                 }
3418         }
3419
3420         /* Check superblock checksum */
3421         if (!ext4_superblock_csum_verify(sb, es)) {
3422                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3423                          "invalid superblock checksum.  Run e2fsck?");
3424                 silent = 1;
3425                 ret = -EFSBADCRC;
3426                 goto cantfind_ext4;
3427         }
3428
3429         /* Precompute checksum seed for all metadata */
3430         if (ext4_has_feature_csum_seed(sb))
3431                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3432         else if (ext4_has_metadata_csum(sb))
3433                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3434                                                sizeof(es->s_uuid));
3435
3436         /* Set defaults before we parse the mount options */
3437         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3438         set_opt(sb, INIT_INODE_TABLE);
3439         if (def_mount_opts & EXT4_DEFM_DEBUG)
3440                 set_opt(sb, DEBUG);
3441         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3442                 set_opt(sb, GRPID);
3443         if (def_mount_opts & EXT4_DEFM_UID16)
3444                 set_opt(sb, NO_UID32);
3445         /* xattr user namespace & acls are now defaulted on */
3446         set_opt(sb, XATTR_USER);
3447 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3448         set_opt(sb, POSIX_ACL);
3449 #endif
3450         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3451         if (ext4_has_metadata_csum(sb))
3452                 set_opt(sb, JOURNAL_CHECKSUM);
3453
3454         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3455                 set_opt(sb, JOURNAL_DATA);
3456         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3457                 set_opt(sb, ORDERED_DATA);
3458         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3459                 set_opt(sb, WRITEBACK_DATA);
3460
3461         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3462                 set_opt(sb, ERRORS_PANIC);
3463         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3464                 set_opt(sb, ERRORS_CONT);
3465         else
3466                 set_opt(sb, ERRORS_RO);
3467         /* block_validity enabled by default; disable with noblock_validity */
3468         set_opt(sb, BLOCK_VALIDITY);
3469         if (def_mount_opts & EXT4_DEFM_DISCARD)
3470                 set_opt(sb, DISCARD);
3471
3472         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3473         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3474         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3475         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3476         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3477
3478         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3479                 set_opt(sb, BARRIER);
3480
3481         /*
3482          * enable delayed allocation by default
3483          * Use -o nodelalloc to turn it off
3484          */
3485         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3486             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3487                 set_opt(sb, DELALLOC);
3488
3489         /*
3490          * set default s_li_wait_mult for lazyinit, for the case there is
3491          * no mount option specified.
3492          */
3493         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3494
3495         if (sbi->s_es->s_mount_opts[0]) {
3496                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3497                                               sizeof(sbi->s_es->s_mount_opts),
3498                                               GFP_KERNEL);
3499                 if (!s_mount_opts)
3500                         goto failed_mount;
3501                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3502                                    &journal_ioprio, 0)) {
3503                         ext4_msg(sb, KERN_WARNING,
3504                                  "failed to parse options in superblock: %s",
3505                                  s_mount_opts);
3506                 }
3507                 kfree(s_mount_opts);
3508         }
3509         sbi->s_def_mount_opt = sbi->s_mount_opt;
3510         if (!parse_options((char *) data, sb, &journal_devnum,
3511                            &journal_ioprio, 0))
3512                 goto failed_mount;
3513
3514         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3515                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3516                             "with data=journal disables delayed "
3517                             "allocation and O_DIRECT support!\n");
3518                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3519                         ext4_msg(sb, KERN_ERR, "can't mount with "
3520                                  "both data=journal and delalloc");
3521                         goto failed_mount;
3522                 }
3523                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3524                         ext4_msg(sb, KERN_ERR, "can't mount with "
3525                                  "both data=journal and dioread_nolock");
3526                         goto failed_mount;
3527                 }
3528                 if (test_opt(sb, DAX)) {
3529                         ext4_msg(sb, KERN_ERR, "can't mount with "
3530                                  "both data=journal and dax");
3531                         goto failed_mount;
3532                 }
3533                 if (ext4_has_feature_encrypt(sb)) {
3534                         ext4_msg(sb, KERN_WARNING,
3535                                  "encrypted files will use data=ordered "
3536                                  "instead of data journaling mode");
3537                 }
3538                 if (test_opt(sb, DELALLOC))
3539                         clear_opt(sb, DELALLOC);
3540         } else {
3541                 sb->s_iflags |= SB_I_CGROUPWB;
3542         }
3543
3544         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3545                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3546
3547         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3548             (ext4_has_compat_features(sb) ||
3549              ext4_has_ro_compat_features(sb) ||
3550              ext4_has_incompat_features(sb)))
3551                 ext4_msg(sb, KERN_WARNING,
3552                        "feature flags set on rev 0 fs, "
3553                        "running e2fsck is recommended");
3554
3555         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3556                 set_opt2(sb, HURD_COMPAT);
3557                 if (ext4_has_feature_64bit(sb)) {
3558                         ext4_msg(sb, KERN_ERR,
3559                                  "The Hurd can't support 64-bit file systems");
3560                         goto failed_mount;
3561                 }
3562         }
3563
3564         if (IS_EXT2_SB(sb)) {
3565                 if (ext2_feature_set_ok(sb))
3566                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3567                                  "using the ext4 subsystem");
3568                 else {
3569                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3570                                  "to feature incompatibilities");
3571                         goto failed_mount;
3572                 }
3573         }
3574
3575         if (IS_EXT3_SB(sb)) {
3576                 if (ext3_feature_set_ok(sb))
3577                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3578                                  "using the ext4 subsystem");
3579                 else {
3580                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3581                                  "to feature incompatibilities");
3582                         goto failed_mount;
3583                 }
3584         }
3585
3586         /*
3587          * Check feature flags regardless of the revision level, since we
3588          * previously didn't change the revision level when setting the flags,
3589          * so there is a chance incompat flags are set on a rev 0 filesystem.
3590          */
3591         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3592                 goto failed_mount;
3593
3594         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3595         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3596             blocksize > EXT4_MAX_BLOCK_SIZE) {
3597                 ext4_msg(sb, KERN_ERR,
3598                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3599                          blocksize, le32_to_cpu(es->s_log_block_size));
3600                 goto failed_mount;
3601         }
3602         if (le32_to_cpu(es->s_log_block_size) >
3603             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3604                 ext4_msg(sb, KERN_ERR,
3605                          "Invalid log block size: %u",
3606                          le32_to_cpu(es->s_log_block_size));
3607                 goto failed_mount;
3608         }
3609
3610         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3611                 ext4_msg(sb, KERN_ERR,
3612                          "Number of reserved GDT blocks insanely large: %d",
3613                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3614                 goto failed_mount;
3615         }
3616
3617         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3618                 err = bdev_dax_supported(sb, blocksize);
3619                 if (err)
3620                         goto failed_mount;
3621         }
3622
3623         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3624                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3625                          es->s_encryption_level);
3626                 goto failed_mount;
3627         }
3628
3629         if (sb->s_blocksize != blocksize) {
3630                 /* Validate the filesystem blocksize */
3631                 if (!sb_set_blocksize(sb, blocksize)) {
3632                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3633                                         blocksize);
3634                         goto failed_mount;
3635                 }
3636
3637                 brelse(bh);
3638                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3639                 offset = do_div(logical_sb_block, blocksize);
3640                 bh = sb_bread_unmovable(sb, logical_sb_block);
3641                 if (!bh) {
3642                         ext4_msg(sb, KERN_ERR,
3643                                "Can't read superblock on 2nd try");
3644                         goto failed_mount;
3645                 }
3646                 es = (struct ext4_super_block *)(bh->b_data + offset);
3647                 sbi->s_es = es;
3648                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3649                         ext4_msg(sb, KERN_ERR,
3650                                "Magic mismatch, very weird!");
3651                         goto failed_mount;
3652                 }
3653         }
3654
3655         has_huge_files = ext4_has_feature_huge_file(sb);
3656         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3657                                                       has_huge_files);
3658         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3659
3660         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3661                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3662                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3663         } else {
3664                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3665                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3666                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3667                     (!is_power_of_2(sbi->s_inode_size)) ||
3668                     (sbi->s_inode_size > blocksize)) {
3669                         ext4_msg(sb, KERN_ERR,
3670                                "unsupported inode size: %d",
3671                                sbi->s_inode_size);
3672                         goto failed_mount;
3673                 }
3674                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3675                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3676         }
3677
3678         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3679         if (ext4_has_feature_64bit(sb)) {
3680                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3681                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3682                     !is_power_of_2(sbi->s_desc_size)) {
3683                         ext4_msg(sb, KERN_ERR,
3684                                "unsupported descriptor size %lu",
3685                                sbi->s_desc_size);
3686                         goto failed_mount;
3687                 }
3688         } else
3689                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3690
3691         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3692         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3693
3694         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3695         if (sbi->s_inodes_per_block == 0)
3696                 goto cantfind_ext4;
3697         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3698             sbi->s_inodes_per_group > blocksize * 8) {
3699                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3700                          sbi->s_blocks_per_group);
3701                 goto failed_mount;
3702         }
3703         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3704                                         sbi->s_inodes_per_block;
3705         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3706         sbi->s_sbh = bh;
3707         sbi->s_mount_state = le16_to_cpu(es->s_state);
3708         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3709         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3710
3711         for (i = 0; i < 4; i++)
3712                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3713         sbi->s_def_hash_version = es->s_def_hash_version;
3714         if (ext4_has_feature_dir_index(sb)) {
3715                 i = le32_to_cpu(es->s_flags);
3716                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3717                         sbi->s_hash_unsigned = 3;
3718                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3719 #ifdef __CHAR_UNSIGNED__
3720                         if (!(sb->s_flags & MS_RDONLY))
3721                                 es->s_flags |=
3722                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3723                         sbi->s_hash_unsigned = 3;
3724 #else
3725                         if (!(sb->s_flags & MS_RDONLY))
3726                                 es->s_flags |=
3727                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3728 #endif
3729                 }
3730         }
3731
3732         /* Handle clustersize */
3733         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3734         has_bigalloc = ext4_has_feature_bigalloc(sb);
3735         if (has_bigalloc) {
3736                 if (clustersize < blocksize) {
3737                         ext4_msg(sb, KERN_ERR,
3738                                  "cluster size (%d) smaller than "
3739                                  "block size (%d)", clustersize, blocksize);
3740                         goto failed_mount;
3741                 }
3742                 if (le32_to_cpu(es->s_log_cluster_size) >
3743                     (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3744                         ext4_msg(sb, KERN_ERR,
3745                                  "Invalid log cluster size: %u",
3746                                  le32_to_cpu(es->s_log_cluster_size));
3747                         goto failed_mount;
3748                 }
3749                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3750                         le32_to_cpu(es->s_log_block_size);
3751                 sbi->s_clusters_per_group =
3752                         le32_to_cpu(es->s_clusters_per_group);
3753                 if (sbi->s_clusters_per_group > blocksize * 8) {
3754                         ext4_msg(sb, KERN_ERR,
3755                                  "#clusters per group too big: %lu",
3756                                  sbi->s_clusters_per_group);
3757                         goto failed_mount;
3758                 }
3759                 if (sbi->s_blocks_per_group !=
3760                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3761                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3762                                  "clusters per group (%lu) inconsistent",
3763                                  sbi->s_blocks_per_group,
3764                                  sbi->s_clusters_per_group);
3765                         goto failed_mount;
3766                 }
3767         } else {
3768                 if (clustersize != blocksize) {
3769                         ext4_warning(sb, "fragment/cluster size (%d) != "
3770                                      "block size (%d)", clustersize,
3771                                      blocksize);
3772                         clustersize = blocksize;
3773                 }
3774                 if (sbi->s_blocks_per_group > blocksize * 8) {
3775                         ext4_msg(sb, KERN_ERR,
3776                                  "#blocks per group too big: %lu",
3777                                  sbi->s_blocks_per_group);
3778                         goto failed_mount;
3779                 }
3780                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3781                 sbi->s_cluster_bits = 0;
3782         }
3783         sbi->s_cluster_ratio = clustersize / blocksize;
3784
3785         /* Do we have standard group size of clustersize * 8 blocks ? */
3786         if (sbi->s_blocks_per_group == clustersize << 3)
3787                 set_opt2(sb, STD_GROUP_SIZE);
3788
3789         /*
3790          * Test whether we have more sectors than will fit in sector_t,
3791          * and whether the max offset is addressable by the page cache.
3792          */
3793         err = generic_check_addressable(sb->s_blocksize_bits,
3794                                         ext4_blocks_count(es));
3795         if (err) {
3796                 ext4_msg(sb, KERN_ERR, "filesystem"
3797                          " too large to mount safely on this system");
3798                 if (sizeof(sector_t) < 8)
3799                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3800                 goto failed_mount;
3801         }
3802
3803         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3804                 goto cantfind_ext4;
3805
3806         /* check blocks count against device size */
3807         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3808         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3809                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3810                        "exceeds size of device (%llu blocks)",
3811                        ext4_blocks_count(es), blocks_count);
3812                 goto failed_mount;
3813         }
3814
3815         /*
3816          * It makes no sense for the first data block to be beyond the end
3817          * of the filesystem.
3818          */
3819         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3820                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3821                          "block %u is beyond end of filesystem (%llu)",
3822                          le32_to_cpu(es->s_first_data_block),
3823                          ext4_blocks_count(es));
3824                 goto failed_mount;
3825         }
3826         blocks_count = (ext4_blocks_count(es) -
3827                         le32_to_cpu(es->s_first_data_block) +
3828                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3829         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3830         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3831                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3832                        "(block count %llu, first data block %u, "
3833                        "blocks per group %lu)", sbi->s_groups_count,
3834                        ext4_blocks_count(es),
3835                        le32_to_cpu(es->s_first_data_block),
3836                        EXT4_BLOCKS_PER_GROUP(sb));
3837                 goto failed_mount;
3838         }
3839         sbi->s_groups_count = blocks_count;
3840         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3841                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3842         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3843                    EXT4_DESC_PER_BLOCK(sb);
3844         if (ext4_has_feature_meta_bg(sb)) {
3845                 if (le32_to_cpu(es->s_first_meta_bg) >= db_count) {
3846                         ext4_msg(sb, KERN_WARNING,
3847                                  "first meta block group too large: %u "
3848                                  "(group descriptor block count %u)",
3849                                  le32_to_cpu(es->s_first_meta_bg), db_count);
3850                         goto failed_mount;
3851                 }
3852         }
3853         sbi->s_group_desc = ext4_kvmalloc(db_count *
3854                                           sizeof(struct buffer_head *),
3855                                           GFP_KERNEL);
3856         if (sbi->s_group_desc == NULL) {
3857                 ext4_msg(sb, KERN_ERR, "not enough memory");
3858                 ret = -ENOMEM;
3859                 goto failed_mount;
3860         }
3861
3862         bgl_lock_init(sbi->s_blockgroup_lock);
3863
3864         for (i = 0; i < db_count; i++) {
3865                 block = descriptor_loc(sb, logical_sb_block, i);
3866                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3867                 if (!sbi->s_group_desc[i]) {
3868                         ext4_msg(sb, KERN_ERR,
3869                                "can't read group descriptor %d", i);
3870                         db_count = i;
3871                         goto failed_mount2;
3872                 }
3873         }
3874         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3875                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3876                 ret = -EFSCORRUPTED;
3877                 goto failed_mount2;
3878         }
3879
3880         sbi->s_gdb_count = db_count;
3881         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3882         spin_lock_init(&sbi->s_next_gen_lock);
3883
3884         setup_timer(&sbi->s_err_report, print_daily_error_info,
3885                 (unsigned long) sb);
3886
3887         /* Register extent status tree shrinker */
3888         if (ext4_es_register_shrinker(sbi))
3889                 goto failed_mount3;
3890
3891         sbi->s_stripe = ext4_get_stripe_size(sbi);
3892         sbi->s_extent_max_zeroout_kb = 32;
3893
3894         /*
3895          * set up enough so that it can read an inode
3896          */
3897         sb->s_op = &ext4_sops;
3898         sb->s_export_op = &ext4_export_ops;
3899         sb->s_xattr = ext4_xattr_handlers;
3900         sb->s_cop = &ext4_cryptops;
3901 #ifdef CONFIG_QUOTA
3902         sb->dq_op = &ext4_quota_operations;
3903         if (ext4_has_feature_quota(sb))
3904                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
3905         else
3906                 sb->s_qcop = &ext4_qctl_operations;
3907         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3908 #endif
3909         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3910
3911         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3912         mutex_init(&sbi->s_orphan_lock);
3913
3914         sb->s_root = NULL;
3915
3916         needs_recovery = (es->s_last_orphan != 0 ||
3917                           ext4_has_feature_journal_needs_recovery(sb));
3918
3919         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3920                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3921                         goto failed_mount3a;
3922
3923         /*
3924          * The first inode we look at is the journal inode.  Don't try
3925          * root first: it may be modified in the journal!
3926          */
3927         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3928                 if (ext4_load_journal(sb, es, journal_devnum))
3929                         goto failed_mount3a;
3930         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3931                    ext4_has_feature_journal_needs_recovery(sb)) {
3932                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3933                        "suppressed and not mounted read-only");
3934                 goto failed_mount_wq;
3935         } else {
3936                 /* Nojournal mode, all journal mount options are illegal */
3937                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3938                         ext4_msg(sb, KERN_ERR, "can't mount with "
3939                                  "journal_checksum, fs mounted w/o journal");
3940                         goto failed_mount_wq;
3941                 }
3942                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3943                         ext4_msg(sb, KERN_ERR, "can't mount with "
3944                                  "journal_async_commit, fs mounted w/o journal");
3945                         goto failed_mount_wq;
3946                 }
3947                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3948                         ext4_msg(sb, KERN_ERR, "can't mount with "
3949                                  "commit=%lu, fs mounted w/o journal",
3950                                  sbi->s_commit_interval / HZ);
3951                         goto failed_mount_wq;
3952                 }
3953                 if (EXT4_MOUNT_DATA_FLAGS &
3954                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3955                         ext4_msg(sb, KERN_ERR, "can't mount with "
3956                                  "data=, fs mounted w/o journal");
3957                         goto failed_mount_wq;
3958                 }
3959                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3960                 clear_opt(sb, JOURNAL_CHECKSUM);
3961                 clear_opt(sb, DATA_FLAGS);
3962                 sbi->s_journal = NULL;
3963                 needs_recovery = 0;
3964                 goto no_journal;
3965         }
3966
3967         if (ext4_has_feature_64bit(sb) &&
3968             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3969                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3970                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3971                 goto failed_mount_wq;
3972         }
3973
3974         if (!set_journal_csum_feature_set(sb)) {
3975                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3976                          "feature set");
3977                 goto failed_mount_wq;
3978         }
3979
3980         /* We have now updated the journal if required, so we can
3981          * validate the data journaling mode. */
3982         switch (test_opt(sb, DATA_FLAGS)) {
3983         case 0:
3984                 /* No mode set, assume a default based on the journal
3985                  * capabilities: ORDERED_DATA if the journal can
3986                  * cope, else JOURNAL_DATA
3987                  */
3988                 if (jbd2_journal_check_available_features
3989                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3990                         set_opt(sb, ORDERED_DATA);
3991                 else
3992                         set_opt(sb, JOURNAL_DATA);
3993                 break;
3994
3995         case EXT4_MOUNT_ORDERED_DATA:
3996         case EXT4_MOUNT_WRITEBACK_DATA:
3997                 if (!jbd2_journal_check_available_features
3998                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3999                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4000                                "requested data journaling mode");
4001                         goto failed_mount_wq;
4002                 }
4003         default:
4004                 break;
4005         }
4006
4007         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4008             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4009                 ext4_msg(sb, KERN_ERR, "can't mount with "
4010                         "journal_async_commit in data=ordered mode");
4011                 goto failed_mount_wq;
4012         }
4013
4014         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4015
4016         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4017
4018 no_journal:
4019         sbi->s_mb_cache = ext4_xattr_create_cache();
4020         if (!sbi->s_mb_cache) {
4021                 ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4022                 goto failed_mount_wq;
4023         }
4024
4025         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4026             (blocksize != PAGE_SIZE)) {
4027                 ext4_msg(sb, KERN_ERR,
4028                          "Unsupported blocksize for fs encryption");
4029                 goto failed_mount_wq;
4030         }
4031
4032         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4033             !ext4_has_feature_encrypt(sb)) {
4034                 ext4_set_feature_encrypt(sb);
4035                 ext4_commit_super(sb, 1);
4036         }
4037
4038         /*
4039          * Get the # of file system overhead blocks from the
4040          * superblock if present.
4041          */
4042         if (es->s_overhead_clusters)
4043                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4044         else {
4045                 err = ext4_calculate_overhead(sb);
4046                 if (err)
4047                         goto failed_mount_wq;
4048         }
4049
4050         /*
4051          * The maximum number of concurrent works can be high and
4052          * concurrency isn't really necessary.  Limit it to 1.
4053          */
4054         EXT4_SB(sb)->rsv_conversion_wq =
4055                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4056         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4057                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4058                 ret = -ENOMEM;
4059                 goto failed_mount4;
4060         }
4061
4062         /*
4063          * The jbd2_journal_load will have done any necessary log recovery,
4064          * so we can safely mount the rest of the filesystem now.
4065          */
4066
4067         root = ext4_iget(sb, EXT4_ROOT_INO);
4068         if (IS_ERR(root)) {
4069                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4070                 ret = PTR_ERR(root);
4071                 root = NULL;
4072                 goto failed_mount4;
4073         }
4074         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4075                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4076                 iput(root);
4077                 goto failed_mount4;
4078         }
4079         sb->s_root = d_make_root(root);
4080         if (!sb->s_root) {
4081                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4082                 ret = -ENOMEM;
4083                 goto failed_mount4;
4084         }
4085
4086         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4087                 sb->s_flags |= MS_RDONLY;
4088
4089         /* determine the minimum size of new large inodes, if present */
4090         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4091                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4092                                                      EXT4_GOOD_OLD_INODE_SIZE;
4093                 if (ext4_has_feature_extra_isize(sb)) {
4094                         if (sbi->s_want_extra_isize <
4095                             le16_to_cpu(es->s_want_extra_isize))
4096                                 sbi->s_want_extra_isize =
4097                                         le16_to_cpu(es->s_want_extra_isize);
4098                         if (sbi->s_want_extra_isize <
4099                             le16_to_cpu(es->s_min_extra_isize))
4100                                 sbi->s_want_extra_isize =
4101                                         le16_to_cpu(es->s_min_extra_isize);
4102                 }
4103         }
4104         /* Check if enough inode space is available */
4105         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4106                                                         sbi->s_inode_size) {
4107                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4108                                                        EXT4_GOOD_OLD_INODE_SIZE;
4109                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4110                          "available");
4111         }
4112
4113         ext4_set_resv_clusters(sb);
4114
4115         err = ext4_setup_system_zone(sb);
4116         if (err) {
4117                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4118                          "zone (%d)", err);
4119                 goto failed_mount4a;
4120         }
4121
4122         ext4_ext_init(sb);
4123         err = ext4_mb_init(sb);
4124         if (err) {
4125                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4126                          err);
4127                 goto failed_mount5;
4128         }
4129
4130         block = ext4_count_free_clusters(sb);
4131         ext4_free_blocks_count_set(sbi->s_es,
4132                                    EXT4_C2B(sbi, block));
4133         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4134                                   GFP_KERNEL);
4135         if (!err) {
4136                 unsigned long freei = ext4_count_free_inodes(sb);
4137                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4138                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4139                                           GFP_KERNEL);
4140         }
4141         if (!err)
4142                 err = percpu_counter_init(&sbi->s_dirs_counter,
4143                                           ext4_count_dirs(sb), GFP_KERNEL);
4144         if (!err)
4145                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4146                                           GFP_KERNEL);
4147         if (!err)
4148                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4149
4150         if (err) {
4151                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4152                 goto failed_mount6;
4153         }
4154
4155         if (ext4_has_feature_flex_bg(sb))
4156                 if (!ext4_fill_flex_info(sb)) {
4157                         ext4_msg(sb, KERN_ERR,
4158                                "unable to initialize "
4159                                "flex_bg meta info!");
4160                         goto failed_mount6;
4161                 }
4162
4163         err = ext4_register_li_request(sb, first_not_zeroed);
4164         if (err)
4165                 goto failed_mount6;
4166
4167         err = ext4_register_sysfs(sb);
4168         if (err)
4169                 goto failed_mount7;
4170
4171 #ifdef CONFIG_QUOTA
4172         /* Enable quota usage during mount. */
4173         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4174                 err = ext4_enable_quotas(sb);
4175                 if (err)
4176                         goto failed_mount8;
4177         }
4178 #endif  /* CONFIG_QUOTA */
4179
4180         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4181         ext4_orphan_cleanup(sb, es);
4182         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4183         if (needs_recovery) {
4184                 ext4_msg(sb, KERN_INFO, "recovery complete");
4185                 ext4_mark_recovery_complete(sb, es);
4186         }
4187         if (EXT4_SB(sb)->s_journal) {
4188                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4189                         descr = " journalled data mode";
4190                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4191                         descr = " ordered data mode";
4192                 else
4193                         descr = " writeback data mode";
4194         } else
4195                 descr = "out journal";
4196
4197         if (test_opt(sb, DISCARD)) {
4198                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4199                 if (!blk_queue_discard(q))
4200                         ext4_msg(sb, KERN_WARNING,
4201                                  "mounting with \"discard\" option, but "
4202                                  "the device does not support discard");
4203         }
4204
4205         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4206                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4207                          "Opts: %.*s%s%s", descr,
4208                          (int) sizeof(sbi->s_es->s_mount_opts),
4209                          sbi->s_es->s_mount_opts,
4210                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4211
4212         if (es->s_error_count)
4213                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4214
4215         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4216         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4217         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4218         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4219
4220         kfree(orig_data);
4221 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4222         memcpy(sbi->key_prefix, EXT4_KEY_DESC_PREFIX,
4223                                 EXT4_KEY_DESC_PREFIX_SIZE);
4224         sbi->key_prefix_size = EXT4_KEY_DESC_PREFIX_SIZE;
4225 #endif
4226         return 0;
4227
4228 cantfind_ext4:
4229         if (!silent)
4230                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4231         goto failed_mount;
4232
4233 #ifdef CONFIG_QUOTA
4234 failed_mount8:
4235         ext4_unregister_sysfs(sb);
4236 #endif
4237 failed_mount7:
4238         ext4_unregister_li_request(sb);
4239 failed_mount6:
4240         ext4_mb_release(sb);
4241         if (sbi->s_flex_groups)
4242                 kvfree(sbi->s_flex_groups);
4243         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4244         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4245         percpu_counter_destroy(&sbi->s_dirs_counter);
4246         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4247 failed_mount5:
4248         ext4_ext_release(sb);
4249         ext4_release_system_zone(sb);
4250 failed_mount4a:
4251         dput(sb->s_root);
4252         sb->s_root = NULL;
4253 failed_mount4:
4254         ext4_msg(sb, KERN_ERR, "mount failed");
4255         if (EXT4_SB(sb)->rsv_conversion_wq)
4256                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4257 failed_mount_wq:
4258         if (sbi->s_mb_cache) {
4259                 ext4_xattr_destroy_cache(sbi->s_mb_cache);
4260                 sbi->s_mb_cache = NULL;
4261         }
4262         if (sbi->s_journal) {
4263                 jbd2_journal_destroy(sbi->s_journal);
4264                 sbi->s_journal = NULL;
4265         }
4266 failed_mount3a:
4267         ext4_es_unregister_shrinker(sbi);
4268 failed_mount3:
4269         del_timer_sync(&sbi->s_err_report);
4270         if (sbi->s_mmp_tsk)
4271                 kthread_stop(sbi->s_mmp_tsk);
4272 failed_mount2:
4273         for (i = 0; i < db_count; i++)
4274                 brelse(sbi->s_group_desc[i]);
4275         kvfree(sbi->s_group_desc);
4276 failed_mount:
4277         if (sbi->s_chksum_driver)
4278                 crypto_free_shash(sbi->s_chksum_driver);
4279 #ifdef CONFIG_QUOTA
4280         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4281                 kfree(sbi->s_qf_names[i]);
4282 #endif
4283         ext4_blkdev_remove(sbi);
4284         brelse(bh);
4285 out_fail:
4286         sb->s_fs_info = NULL;
4287         kfree(sbi->s_blockgroup_lock);
4288 out_free_base:
4289         kfree(sbi);
4290         kfree(orig_data);
4291         return err ? err : ret;
4292 }
4293
4294 /*
4295  * Setup any per-fs journal parameters now.  We'll do this both on
4296  * initial mount, once the journal has been initialised but before we've
4297  * done any recovery; and again on any subsequent remount.
4298  */
4299 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4300 {
4301         struct ext4_sb_info *sbi = EXT4_SB(sb);
4302
4303         journal->j_commit_interval = sbi->s_commit_interval;
4304         journal->j_min_batch_time = sbi->s_min_batch_time;
4305         journal->j_max_batch_time = sbi->s_max_batch_time;
4306
4307         write_lock(&journal->j_state_lock);
4308         if (test_opt(sb, BARRIER))
4309                 journal->j_flags |= JBD2_BARRIER;
4310         else
4311                 journal->j_flags &= ~JBD2_BARRIER;
4312         if (test_opt(sb, DATA_ERR_ABORT))
4313                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4314         else
4315                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4316         write_unlock(&journal->j_state_lock);
4317 }
4318
4319 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4320                                              unsigned int journal_inum)
4321 {
4322         struct inode *journal_inode;
4323
4324         /*
4325          * Test for the existence of a valid inode on disk.  Bad things
4326          * happen if we iget() an unused inode, as the subsequent iput()
4327          * will try to delete it.
4328          */
4329         journal_inode = ext4_iget(sb, journal_inum);
4330         if (IS_ERR(journal_inode)) {
4331                 ext4_msg(sb, KERN_ERR, "no journal found");
4332                 return NULL;
4333         }
4334         if (!journal_inode->i_nlink) {
4335                 make_bad_inode(journal_inode);
4336                 iput(journal_inode);
4337                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4338                 return NULL;
4339         }
4340
4341         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4342                   journal_inode, journal_inode->i_size);
4343         if (!S_ISREG(journal_inode->i_mode)) {
4344                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4345                 iput(journal_inode);
4346                 return NULL;
4347         }
4348         return journal_inode;
4349 }
4350
4351 static journal_t *ext4_get_journal(struct super_block *sb,
4352                                    unsigned int journal_inum)
4353 {
4354         struct inode *journal_inode;
4355         journal_t *journal;
4356
4357         BUG_ON(!ext4_has_feature_journal(sb));
4358
4359         journal_inode = ext4_get_journal_inode(sb, journal_inum);
4360         if (!journal_inode)
4361                 return NULL;
4362
4363         journal = jbd2_journal_init_inode(journal_inode);
4364         if (!journal) {
4365                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4366                 iput(journal_inode);
4367                 return NULL;
4368         }
4369         journal->j_private = sb;
4370         ext4_init_journal_params(sb, journal);
4371         return journal;
4372 }
4373
4374 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4375                                        dev_t j_dev)
4376 {
4377         struct buffer_head *bh;
4378         journal_t *journal;
4379         ext4_fsblk_t start;
4380         ext4_fsblk_t len;
4381         int hblock, blocksize;
4382         ext4_fsblk_t sb_block;
4383         unsigned long offset;
4384         struct ext4_super_block *es;
4385         struct block_device *bdev;
4386
4387         BUG_ON(!ext4_has_feature_journal(sb));
4388
4389         bdev = ext4_blkdev_get(j_dev, sb);
4390         if (bdev == NULL)
4391                 return NULL;
4392
4393         blocksize = sb->s_blocksize;
4394         hblock = bdev_logical_block_size(bdev);
4395         if (blocksize < hblock) {
4396                 ext4_msg(sb, KERN_ERR,
4397                         "blocksize too small for journal device");
4398                 goto out_bdev;
4399         }
4400
4401         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4402         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4403         set_blocksize(bdev, blocksize);
4404         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4405                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4406                        "external journal");
4407                 goto out_bdev;
4408         }
4409
4410         es = (struct ext4_super_block *) (bh->b_data + offset);
4411         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4412             !(le32_to_cpu(es->s_feature_incompat) &
4413               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4414                 ext4_msg(sb, KERN_ERR, "external journal has "
4415                                         "bad superblock");
4416                 brelse(bh);
4417                 goto out_bdev;
4418         }
4419
4420         if ((le32_to_cpu(es->s_feature_ro_compat) &
4421              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4422             es->s_checksum != ext4_superblock_csum(sb, es)) {
4423                 ext4_msg(sb, KERN_ERR, "external journal has "
4424                                        "corrupt superblock");
4425                 brelse(bh);
4426                 goto out_bdev;
4427         }
4428
4429         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4430                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4431                 brelse(bh);
4432                 goto out_bdev;
4433         }
4434
4435         len = ext4_blocks_count(es);
4436         start = sb_block + 1;
4437         brelse(bh);     /* we're done with the superblock */
4438
4439         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4440                                         start, len, blocksize);
4441         if (!journal) {
4442                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4443                 goto out_bdev;
4444         }
4445         journal->j_private = sb;
4446         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4447         wait_on_buffer(journal->j_sb_buffer);
4448         if (!buffer_uptodate(journal->j_sb_buffer)) {
4449                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4450                 goto out_journal;
4451         }
4452         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4453                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4454                                         "user (unsupported) - %d",
4455                         be32_to_cpu(journal->j_superblock->s_nr_users));
4456                 goto out_journal;
4457         }
4458         EXT4_SB(sb)->journal_bdev = bdev;
4459         ext4_init_journal_params(sb, journal);
4460         return journal;
4461
4462 out_journal:
4463         jbd2_journal_destroy(journal);
4464 out_bdev:
4465         ext4_blkdev_put(bdev);
4466         return NULL;
4467 }
4468
4469 static int ext4_load_journal(struct super_block *sb,
4470                              struct ext4_super_block *es,
4471                              unsigned long journal_devnum)
4472 {
4473         journal_t *journal;
4474         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4475         dev_t journal_dev;
4476         int err = 0;
4477         int really_read_only;
4478
4479         BUG_ON(!ext4_has_feature_journal(sb));
4480
4481         if (journal_devnum &&
4482             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4483                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4484                         "numbers have changed");
4485                 journal_dev = new_decode_dev(journal_devnum);
4486         } else
4487                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4488
4489         really_read_only = bdev_read_only(sb->s_bdev);
4490
4491         /*
4492          * Are we loading a blank journal or performing recovery after a
4493          * crash?  For recovery, we need to check in advance whether we
4494          * can get read-write access to the device.
4495          */
4496         if (ext4_has_feature_journal_needs_recovery(sb)) {
4497                 if (sb->s_flags & MS_RDONLY) {
4498                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4499                                         "required on readonly filesystem");
4500                         if (really_read_only) {
4501                                 ext4_msg(sb, KERN_ERR, "write access "
4502                                         "unavailable, cannot proceed");
4503                                 return -EROFS;
4504                         }
4505                         ext4_msg(sb, KERN_INFO, "write access will "
4506                                "be enabled during recovery");
4507                 }
4508         }
4509
4510         if (journal_inum && journal_dev) {
4511                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4512                        "and inode journals!");
4513                 return -EINVAL;
4514         }
4515
4516         if (journal_inum) {
4517                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4518                         return -EINVAL;
4519         } else {
4520                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4521                         return -EINVAL;
4522         }
4523
4524         if (!(journal->j_flags & JBD2_BARRIER))
4525                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4526
4527         if (!ext4_has_feature_journal_needs_recovery(sb))
4528                 err = jbd2_journal_wipe(journal, !really_read_only);
4529         if (!err) {
4530                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4531                 if (save)
4532                         memcpy(save, ((char *) es) +
4533                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4534                 err = jbd2_journal_load(journal);
4535                 if (save)
4536                         memcpy(((char *) es) + EXT4_S_ERR_START,
4537                                save, EXT4_S_ERR_LEN);
4538                 kfree(save);
4539         }
4540
4541         if (err) {
4542                 ext4_msg(sb, KERN_ERR, "error loading journal");
4543                 jbd2_journal_destroy(journal);
4544                 return err;
4545         }
4546
4547         EXT4_SB(sb)->s_journal = journal;
4548         ext4_clear_journal_err(sb, es);
4549
4550         if (!really_read_only && journal_devnum &&
4551             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4552                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4553
4554                 /* Make sure we flush the recovery flag to disk. */
4555                 ext4_commit_super(sb, 1);
4556         }
4557
4558         return 0;
4559 }
4560
4561 static int ext4_commit_super(struct super_block *sb, int sync)
4562 {
4563         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4564         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4565         int error = 0;
4566
4567         if (!sbh || block_device_ejected(sb))
4568                 return error;
4569         /*
4570          * If the file system is mounted read-only, don't update the
4571          * superblock write time.  This avoids updating the superblock
4572          * write time when we are mounting the root file system
4573          * read/only but we need to replay the journal; at that point,
4574          * for people who are east of GMT and who make their clock
4575          * tick in localtime for Windows bug-for-bug compatibility,
4576          * the clock is set in the future, and this will cause e2fsck
4577          * to complain and force a full file system check.
4578          */
4579         if (!(sb->s_flags & MS_RDONLY))
4580                 es->s_wtime = cpu_to_le32(get_seconds());
4581         if (sb->s_bdev->bd_part)
4582                 es->s_kbytes_written =
4583                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4584                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4585                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4586         else
4587                 es->s_kbytes_written =
4588                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4589         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4590                 ext4_free_blocks_count_set(es,
4591                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4592                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4593         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4594                 es->s_free_inodes_count =
4595                         cpu_to_le32(percpu_counter_sum_positive(
4596                                 &EXT4_SB(sb)->s_freeinodes_counter));
4597         BUFFER_TRACE(sbh, "marking dirty");
4598         ext4_superblock_csum_set(sb);
4599         if (sync)
4600                 lock_buffer(sbh);
4601         if (buffer_write_io_error(sbh)) {
4602                 /*
4603                  * Oh, dear.  A previous attempt to write the
4604                  * superblock failed.  This could happen because the
4605                  * USB device was yanked out.  Or it could happen to
4606                  * be a transient write error and maybe the block will
4607                  * be remapped.  Nothing we can do but to retry the
4608                  * write and hope for the best.
4609                  */
4610                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4611                        "superblock detected");
4612                 clear_buffer_write_io_error(sbh);
4613                 set_buffer_uptodate(sbh);
4614         }
4615         mark_buffer_dirty(sbh);
4616         if (sync) {
4617                 unlock_buffer(sbh);
4618                 error = __sync_dirty_buffer(sbh,
4619                         test_opt(sb, BARRIER) ? REQ_FUA : REQ_SYNC);
4620                 if (error)
4621                         return error;
4622
4623                 error = buffer_write_io_error(sbh);
4624                 if (error) {
4625                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4626                                "superblock");
4627                         clear_buffer_write_io_error(sbh);
4628                         set_buffer_uptodate(sbh);
4629                 }
4630         }
4631         return error;
4632 }
4633
4634 /*
4635  * Have we just finished recovery?  If so, and if we are mounting (or
4636  * remounting) the filesystem readonly, then we will end up with a
4637  * consistent fs on disk.  Record that fact.
4638  */
4639 static void ext4_mark_recovery_complete(struct super_block *sb,
4640                                         struct ext4_super_block *es)
4641 {
4642         journal_t *journal = EXT4_SB(sb)->s_journal;
4643
4644         if (!ext4_has_feature_journal(sb)) {
4645                 BUG_ON(journal != NULL);
4646                 return;
4647         }
4648         jbd2_journal_lock_updates(journal);
4649         if (jbd2_journal_flush(journal) < 0)
4650                 goto out;
4651
4652         if (ext4_has_feature_journal_needs_recovery(sb) &&
4653             sb->s_flags & MS_RDONLY) {
4654                 ext4_clear_feature_journal_needs_recovery(sb);
4655                 ext4_commit_super(sb, 1);
4656         }
4657
4658 out:
4659         jbd2_journal_unlock_updates(journal);
4660 }
4661
4662 /*
4663  * If we are mounting (or read-write remounting) a filesystem whose journal
4664  * has recorded an error from a previous lifetime, move that error to the
4665  * main filesystem now.
4666  */
4667 static void ext4_clear_journal_err(struct super_block *sb,
4668                                    struct ext4_super_block *es)
4669 {
4670         journal_t *journal;
4671         int j_errno;
4672         const char *errstr;
4673
4674         BUG_ON(!ext4_has_feature_journal(sb));
4675
4676         journal = EXT4_SB(sb)->s_journal;
4677
4678         /*
4679          * Now check for any error status which may have been recorded in the
4680          * journal by a prior ext4_error() or ext4_abort()
4681          */
4682
4683         j_errno = jbd2_journal_errno(journal);
4684         if (j_errno) {
4685                 char nbuf[16];
4686
4687                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4688                 ext4_warning(sb, "Filesystem error recorded "
4689                              "from previous mount: %s", errstr);
4690                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4691
4692                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4693                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4694                 ext4_commit_super(sb, 1);
4695
4696                 jbd2_journal_clear_err(journal);
4697                 jbd2_journal_update_sb_errno(journal);
4698         }
4699 }
4700
4701 /*
4702  * Force the running and committing transactions to commit,
4703  * and wait on the commit.
4704  */
4705 int ext4_force_commit(struct super_block *sb)
4706 {
4707         journal_t *journal;
4708
4709         if (sb->s_flags & MS_RDONLY)
4710                 return 0;
4711
4712         journal = EXT4_SB(sb)->s_journal;
4713         return ext4_journal_force_commit(journal);
4714 }
4715
4716 static int ext4_sync_fs(struct super_block *sb, int wait)
4717 {
4718         int ret = 0;
4719         tid_t target;
4720         bool needs_barrier = false;
4721         struct ext4_sb_info *sbi = EXT4_SB(sb);
4722
4723         trace_ext4_sync_fs(sb, wait);
4724         flush_workqueue(sbi->rsv_conversion_wq);
4725         /*
4726          * Writeback quota in non-journalled quota case - journalled quota has
4727          * no dirty dquots
4728          */
4729         dquot_writeback_dquots(sb, -1);
4730         /*
4731          * Data writeback is possible w/o journal transaction, so barrier must
4732          * being sent at the end of the function. But we can skip it if
4733          * transaction_commit will do it for us.
4734          */
4735         if (sbi->s_journal) {
4736                 target = jbd2_get_latest_transaction(sbi->s_journal);
4737                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4738                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4739                         needs_barrier = true;
4740
4741                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4742                         if (wait)
4743                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4744                                                            target);
4745                 }
4746         } else if (wait && test_opt(sb, BARRIER))
4747                 needs_barrier = true;
4748         if (needs_barrier) {
4749                 int err;
4750                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4751                 if (!ret)
4752                         ret = err;
4753         }
4754
4755         return ret;
4756 }
4757
4758 /*
4759  * LVM calls this function before a (read-only) snapshot is created.  This
4760  * gives us a chance to flush the journal completely and mark the fs clean.
4761  *
4762  * Note that only this function cannot bring a filesystem to be in a clean
4763  * state independently. It relies on upper layer to stop all data & metadata
4764  * modifications.
4765  */
4766 static int ext4_freeze(struct super_block *sb)
4767 {
4768         int error = 0;
4769         journal_t *journal;
4770
4771         if (sb->s_flags & MS_RDONLY)
4772                 return 0;
4773
4774         journal = EXT4_SB(sb)->s_journal;
4775
4776         if (journal) {
4777                 /* Now we set up the journal barrier. */
4778                 jbd2_journal_lock_updates(journal);
4779
4780                 /*
4781                  * Don't clear the needs_recovery flag if we failed to
4782                  * flush the journal.
4783                  */
4784                 error = jbd2_journal_flush(journal);
4785                 if (error < 0)
4786                         goto out;
4787
4788                 /* Journal blocked and flushed, clear needs_recovery flag. */
4789                 ext4_clear_feature_journal_needs_recovery(sb);
4790         }
4791
4792         error = ext4_commit_super(sb, 1);
4793 out:
4794         if (journal)
4795                 /* we rely on upper layer to stop further updates */
4796                 jbd2_journal_unlock_updates(journal);
4797         return error;
4798 }
4799
4800 /*
4801  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4802  * flag here, even though the filesystem is not technically dirty yet.
4803  */
4804 static int ext4_unfreeze(struct super_block *sb)
4805 {
4806         if (sb->s_flags & MS_RDONLY)
4807                 return 0;
4808
4809         if (EXT4_SB(sb)->s_journal) {
4810                 /* Reset the needs_recovery flag before the fs is unlocked. */
4811                 ext4_set_feature_journal_needs_recovery(sb);
4812         }
4813
4814         ext4_commit_super(sb, 1);
4815         return 0;
4816 }
4817
4818 /*
4819  * Structure to save mount options for ext4_remount's benefit
4820  */
4821 struct ext4_mount_options {
4822         unsigned long s_mount_opt;
4823         unsigned long s_mount_opt2;
4824         kuid_t s_resuid;
4825         kgid_t s_resgid;
4826         unsigned long s_commit_interval;
4827         u32 s_min_batch_time, s_max_batch_time;
4828 #ifdef CONFIG_QUOTA
4829         int s_jquota_fmt;
4830         char *s_qf_names[EXT4_MAXQUOTAS];
4831 #endif
4832 };
4833
4834 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4835 {
4836         struct ext4_super_block *es;
4837         struct ext4_sb_info *sbi = EXT4_SB(sb);
4838         unsigned long old_sb_flags;
4839         struct ext4_mount_options old_opts;
4840         int enable_quota = 0;
4841         ext4_group_t g;
4842         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4843         int err = 0;
4844 #ifdef CONFIG_QUOTA
4845         int i, j;
4846 #endif
4847         char *orig_data = kstrdup(data, GFP_KERNEL);
4848
4849         /* Store the original options */
4850         old_sb_flags = sb->s_flags;
4851         old_opts.s_mount_opt = sbi->s_mount_opt;
4852         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4853         old_opts.s_resuid = sbi->s_resuid;
4854         old_opts.s_resgid = sbi->s_resgid;
4855         old_opts.s_commit_interval = sbi->s_commit_interval;
4856         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4857         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4858 #ifdef CONFIG_QUOTA
4859         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4860         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4861                 if (sbi->s_qf_names[i]) {
4862                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4863                                                          GFP_KERNEL);
4864                         if (!old_opts.s_qf_names[i]) {
4865                                 for (j = 0; j < i; j++)
4866                                         kfree(old_opts.s_qf_names[j]);
4867                                 kfree(orig_data);
4868                                 return -ENOMEM;
4869                         }
4870                 } else
4871                         old_opts.s_qf_names[i] = NULL;
4872 #endif
4873         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4874                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4875
4876         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4877                 err = -EINVAL;
4878                 goto restore_opts;
4879         }
4880
4881         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4882             test_opt(sb, JOURNAL_CHECKSUM)) {
4883                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4884                          "during remount not supported; ignoring");
4885                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4886         }
4887
4888         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4889                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4890                         ext4_msg(sb, KERN_ERR, "can't mount with "
4891                                  "both data=journal and delalloc");
4892                         err = -EINVAL;
4893                         goto restore_opts;
4894                 }
4895                 if (test_opt(sb, DIOREAD_NOLOCK)) {
4896                         ext4_msg(sb, KERN_ERR, "can't mount with "
4897                                  "both data=journal and dioread_nolock");
4898                         err = -EINVAL;
4899                         goto restore_opts;
4900                 }
4901                 if (test_opt(sb, DAX)) {
4902                         ext4_msg(sb, KERN_ERR, "can't mount with "
4903                                  "both data=journal and dax");
4904                         err = -EINVAL;
4905                         goto restore_opts;
4906                 }
4907         } else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
4908                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4909                         ext4_msg(sb, KERN_ERR, "can't mount with "
4910                                 "journal_async_commit in data=ordered mode");
4911                         err = -EINVAL;
4912                         goto restore_opts;
4913                 }
4914         }
4915
4916         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4917                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4918                         "dax flag with busy inodes while remounting");
4919                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4920         }
4921
4922         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4923                 ext4_abort(sb, "Abort forced by user");
4924
4925         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4926                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4927
4928         es = sbi->s_es;
4929
4930         if (sbi->s_journal) {
4931                 ext4_init_journal_params(sb, sbi->s_journal);
4932                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4933         }
4934
4935         if (*flags & MS_LAZYTIME)
4936                 sb->s_flags |= MS_LAZYTIME;
4937
4938         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4939                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4940                         err = -EROFS;
4941                         goto restore_opts;
4942                 }
4943
4944                 if (*flags & MS_RDONLY) {
4945                         err = sync_filesystem(sb);
4946                         if (err < 0)
4947                                 goto restore_opts;
4948                         err = dquot_suspend(sb, -1);
4949                         if (err < 0)
4950                                 goto restore_opts;
4951
4952                         /*
4953                          * First of all, the unconditional stuff we have to do
4954                          * to disable replay of the journal when we next remount
4955                          */
4956                         sb->s_flags |= MS_RDONLY;
4957
4958                         /*
4959                          * OK, test if we are remounting a valid rw partition
4960                          * readonly, and if so set the rdonly flag and then
4961                          * mark the partition as valid again.
4962                          */
4963                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4964                             (sbi->s_mount_state & EXT4_VALID_FS))
4965                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4966
4967                         if (sbi->s_journal)
4968                                 ext4_mark_recovery_complete(sb, es);
4969                 } else {
4970                         /* Make sure we can mount this feature set readwrite */
4971                         if (ext4_has_feature_readonly(sb) ||
4972                             !ext4_feature_set_ok(sb, 0)) {
4973                                 err = -EROFS;
4974                                 goto restore_opts;
4975                         }
4976                         /*
4977                          * Make sure the group descriptor checksums
4978                          * are sane.  If they aren't, refuse to remount r/w.
4979                          */
4980                         for (g = 0; g < sbi->s_groups_count; g++) {
4981                                 struct ext4_group_desc *gdp =
4982                                         ext4_get_group_desc(sb, g, NULL);
4983
4984                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4985                                         ext4_msg(sb, KERN_ERR,
4986                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4987                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4988                                                le16_to_cpu(gdp->bg_checksum));
4989                                         err = -EFSBADCRC;
4990                                         goto restore_opts;
4991                                 }
4992                         }
4993
4994                         /*
4995                          * If we have an unprocessed orphan list hanging
4996                          * around from a previously readonly bdev mount,
4997                          * require a full umount/remount for now.
4998                          */
4999                         if (es->s_last_orphan) {
5000                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
5001                                        "remount RDWR because of unprocessed "
5002                                        "orphan inode list.  Please "
5003                                        "umount/remount instead");
5004                                 err = -EINVAL;
5005                                 goto restore_opts;
5006                         }
5007
5008                         /*
5009                          * Mounting a RDONLY partition read-write, so reread
5010                          * and store the current valid flag.  (It may have
5011                          * been changed by e2fsck since we originally mounted
5012                          * the partition.)
5013                          */
5014                         if (sbi->s_journal)
5015                                 ext4_clear_journal_err(sb, es);
5016                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5017                         if (!ext4_setup_super(sb, es, 0))
5018                                 sb->s_flags &= ~MS_RDONLY;
5019                         if (ext4_has_feature_mmp(sb))
5020                                 if (ext4_multi_mount_protect(sb,
5021                                                 le64_to_cpu(es->s_mmp_block))) {
5022                                         err = -EROFS;
5023                                         goto restore_opts;
5024                                 }
5025                         enable_quota = 1;
5026                 }
5027         }
5028
5029         /*
5030          * Reinitialize lazy itable initialization thread based on
5031          * current settings
5032          */
5033         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5034                 ext4_unregister_li_request(sb);
5035         else {
5036                 ext4_group_t first_not_zeroed;
5037                 first_not_zeroed = ext4_has_uninit_itable(sb);
5038                 ext4_register_li_request(sb, first_not_zeroed);
5039         }
5040
5041         ext4_setup_system_zone(sb);
5042         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5043                 ext4_commit_super(sb, 1);
5044
5045 #ifdef CONFIG_QUOTA
5046         /* Release old quota file names */
5047         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5048                 kfree(old_opts.s_qf_names[i]);
5049         if (enable_quota) {
5050                 if (sb_any_quota_suspended(sb))
5051                         dquot_resume(sb, -1);
5052                 else if (ext4_has_feature_quota(sb)) {
5053                         err = ext4_enable_quotas(sb);
5054                         if (err)
5055                                 goto restore_opts;
5056                 }
5057         }
5058 #endif
5059
5060         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5061         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5062         kfree(orig_data);
5063         return 0;
5064
5065 restore_opts:
5066         sb->s_flags = old_sb_flags;
5067         sbi->s_mount_opt = old_opts.s_mount_opt;
5068         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5069         sbi->s_resuid = old_opts.s_resuid;
5070         sbi->s_resgid = old_opts.s_resgid;
5071         sbi->s_commit_interval = old_opts.s_commit_interval;
5072         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5073         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5074 #ifdef CONFIG_QUOTA
5075         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5076         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5077                 kfree(sbi->s_qf_names[i]);
5078                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5079         }
5080 #endif
5081         kfree(orig_data);
5082         return err;
5083 }
5084
5085 #ifdef CONFIG_QUOTA
5086 static int ext4_statfs_project(struct super_block *sb,
5087                                kprojid_t projid, struct kstatfs *buf)
5088 {
5089         struct kqid qid;
5090         struct dquot *dquot;
5091         u64 limit;
5092         u64 curblock;
5093
5094         qid = make_kqid_projid(projid);
5095         dquot = dqget(sb, qid);
5096         if (IS_ERR(dquot))
5097                 return PTR_ERR(dquot);
5098         spin_lock(&dq_data_lock);
5099
5100         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5101                  dquot->dq_dqb.dqb_bsoftlimit :
5102                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5103         if (limit && buf->f_blocks > limit) {
5104                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5105                 buf->f_blocks = limit;
5106                 buf->f_bfree = buf->f_bavail =
5107                         (buf->f_blocks > curblock) ?
5108                          (buf->f_blocks - curblock) : 0;
5109         }
5110
5111         limit = dquot->dq_dqb.dqb_isoftlimit ?
5112                 dquot->dq_dqb.dqb_isoftlimit :
5113                 dquot->dq_dqb.dqb_ihardlimit;
5114         if (limit && buf->f_files > limit) {
5115                 buf->f_files = limit;
5116                 buf->f_ffree =
5117                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5118                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5119         }
5120
5121         spin_unlock(&dq_data_lock);
5122         dqput(dquot);
5123         return 0;
5124 }
5125 #endif
5126
5127 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5128 {
5129         struct super_block *sb = dentry->d_sb;
5130         struct ext4_sb_info *sbi = EXT4_SB(sb);
5131         struct ext4_super_block *es = sbi->s_es;
5132         ext4_fsblk_t overhead = 0, resv_blocks;
5133         u64 fsid;
5134         s64 bfree;
5135         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5136
5137         if (!test_opt(sb, MINIX_DF))
5138                 overhead = sbi->s_overhead;
5139
5140         buf->f_type = EXT4_SUPER_MAGIC;
5141         buf->f_bsize = sb->s_blocksize;
5142         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5143         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5144                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5145         /* prevent underflow in case that few free space is available */
5146         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5147         buf->f_bavail = buf->f_bfree -
5148                         (ext4_r_blocks_count(es) + resv_blocks);
5149         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5150                 buf->f_bavail = 0;
5151         buf->f_files = le32_to_cpu(es->s_inodes_count);
5152         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5153         buf->f_namelen = EXT4_NAME_LEN;
5154         fsid = le64_to_cpup((void *)es->s_uuid) ^
5155                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5156         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5157         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5158
5159 #ifdef CONFIG_QUOTA
5160         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5161             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5162                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5163 #endif
5164         return 0;
5165 }
5166
5167 /* Helper function for writing quotas on sync - we need to start transaction
5168  * before quota file is locked for write. Otherwise the are possible deadlocks:
5169  * Process 1                         Process 2
5170  * ext4_create()                     quota_sync()
5171  *   jbd2_journal_start()                  write_dquot()
5172  *   dquot_initialize()                         down(dqio_mutex)
5173  *     down(dqio_mutex)                    jbd2_journal_start()
5174  *
5175  */
5176
5177 #ifdef CONFIG_QUOTA
5178
5179 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5180 {
5181         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5182 }
5183
5184 static int ext4_write_dquot(struct dquot *dquot)
5185 {
5186         int ret, err;
5187         handle_t *handle;
5188         struct inode *inode;
5189
5190         inode = dquot_to_inode(dquot);
5191         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5192                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5193         if (IS_ERR(handle))
5194                 return PTR_ERR(handle);
5195         ret = dquot_commit(dquot);
5196         err = ext4_journal_stop(handle);
5197         if (!ret)
5198                 ret = err;
5199         return ret;
5200 }
5201
5202 static int ext4_acquire_dquot(struct dquot *dquot)
5203 {
5204         int ret, err;
5205         handle_t *handle;
5206
5207         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5208                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5209         if (IS_ERR(handle))
5210                 return PTR_ERR(handle);
5211         ret = dquot_acquire(dquot);
5212         err = ext4_journal_stop(handle);
5213         if (!ret)
5214                 ret = err;
5215         return ret;
5216 }
5217
5218 static int ext4_release_dquot(struct dquot *dquot)
5219 {
5220         int ret, err;
5221         handle_t *handle;
5222
5223         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5224                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5225         if (IS_ERR(handle)) {
5226                 /* Release dquot anyway to avoid endless cycle in dqput() */
5227                 dquot_release(dquot);
5228                 return PTR_ERR(handle);
5229         }
5230         ret = dquot_release(dquot);
5231         err = ext4_journal_stop(handle);
5232         if (!ret)
5233                 ret = err;
5234         return ret;
5235 }
5236
5237 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5238 {
5239         struct super_block *sb = dquot->dq_sb;
5240         struct ext4_sb_info *sbi = EXT4_SB(sb);
5241
5242         /* Are we journaling quotas? */
5243         if (ext4_has_feature_quota(sb) ||
5244             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5245                 dquot_mark_dquot_dirty(dquot);
5246                 return ext4_write_dquot(dquot);
5247         } else {
5248                 return dquot_mark_dquot_dirty(dquot);
5249         }
5250 }
5251
5252 static int ext4_write_info(struct super_block *sb, int type)
5253 {
5254         int ret, err;
5255         handle_t *handle;
5256
5257         /* Data block + inode block */
5258         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5259         if (IS_ERR(handle))
5260                 return PTR_ERR(handle);
5261         ret = dquot_commit_info(sb, type);
5262         err = ext4_journal_stop(handle);
5263         if (!ret)
5264                 ret = err;
5265         return ret;
5266 }
5267
5268 /*
5269  * Turn on quotas during mount time - we need to find
5270  * the quota file and such...
5271  */
5272 static int ext4_quota_on_mount(struct super_block *sb, int type)
5273 {
5274         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5275                                         EXT4_SB(sb)->s_jquota_fmt, type);
5276 }
5277
5278 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5279 {
5280         struct ext4_inode_info *ei = EXT4_I(inode);
5281
5282         /* The first argument of lockdep_set_subclass has to be
5283          * *exactly* the same as the argument to init_rwsem() --- in
5284          * this case, in init_once() --- or lockdep gets unhappy
5285          * because the name of the lock is set using the
5286          * stringification of the argument to init_rwsem().
5287          */
5288         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5289         lockdep_set_subclass(&ei->i_data_sem, subclass);
5290 }
5291
5292 /*
5293  * Standard function to be called on quota_on
5294  */
5295 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5296                          const struct path *path)
5297 {
5298         int err;
5299
5300         if (!test_opt(sb, QUOTA))
5301                 return -EINVAL;
5302
5303         /* Quotafile not on the same filesystem? */
5304         if (path->dentry->d_sb != sb)
5305                 return -EXDEV;
5306         /* Journaling quota? */
5307         if (EXT4_SB(sb)->s_qf_names[type]) {
5308                 /* Quotafile not in fs root? */
5309                 if (path->dentry->d_parent != sb->s_root)
5310                         ext4_msg(sb, KERN_WARNING,
5311                                 "Quota file not on filesystem root. "
5312                                 "Journaled quota will not work");
5313         }
5314
5315         /*
5316          * When we journal data on quota file, we have to flush journal to see
5317          * all updates to the file when we bypass pagecache...
5318          */
5319         if (EXT4_SB(sb)->s_journal &&
5320             ext4_should_journal_data(d_inode(path->dentry))) {
5321                 /*
5322                  * We don't need to lock updates but journal_flush() could
5323                  * otherwise be livelocked...
5324                  */
5325                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5326                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5327                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5328                 if (err)
5329                         return err;
5330         }
5331         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5332         err = dquot_quota_on(sb, type, format_id, path);
5333         if (err)
5334                 lockdep_set_quota_inode(path->dentry->d_inode,
5335                                              I_DATA_SEM_NORMAL);
5336         return err;
5337 }
5338
5339 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5340                              unsigned int flags)
5341 {
5342         int err;
5343         struct inode *qf_inode;
5344         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5345                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5346                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5347                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5348         };
5349
5350         BUG_ON(!ext4_has_feature_quota(sb));
5351
5352         if (!qf_inums[type])
5353                 return -EPERM;
5354
5355         qf_inode = ext4_iget(sb, qf_inums[type]);
5356         if (IS_ERR(qf_inode)) {
5357                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5358                 return PTR_ERR(qf_inode);
5359         }
5360
5361         /* Don't account quota for quota files to avoid recursion */
5362         qf_inode->i_flags |= S_NOQUOTA;
5363         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5364         err = dquot_enable(qf_inode, type, format_id, flags);
5365         iput(qf_inode);
5366         if (err)
5367                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5368
5369         return err;
5370 }
5371
5372 /* Enable usage tracking for all quota types. */
5373 static int ext4_enable_quotas(struct super_block *sb)
5374 {
5375         int type, err = 0;
5376         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5377                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5378                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5379                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5380         };
5381         bool quota_mopt[EXT4_MAXQUOTAS] = {
5382                 test_opt(sb, USRQUOTA),
5383                 test_opt(sb, GRPQUOTA),
5384                 test_opt(sb, PRJQUOTA),
5385         };
5386
5387         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5388         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5389                 if (qf_inums[type]) {
5390                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5391                                 DQUOT_USAGE_ENABLED |
5392                                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5393                         if (err) {
5394                                 ext4_warning(sb,
5395                                         "Failed to enable quota tracking "
5396                                         "(type=%d, err=%d). Please run "
5397                                         "e2fsck to fix.", type, err);
5398                                 return err;
5399                         }
5400                 }
5401         }
5402         return 0;
5403 }
5404
5405 static int ext4_quota_off(struct super_block *sb, int type)
5406 {
5407         struct inode *inode = sb_dqopt(sb)->files[type];
5408         handle_t *handle;
5409
5410         /* Force all delayed allocation blocks to be allocated.
5411          * Caller already holds s_umount sem */
5412         if (test_opt(sb, DELALLOC))
5413                 sync_filesystem(sb);
5414
5415         if (!inode)
5416                 goto out;
5417
5418         /* Update modification times of quota files when userspace can
5419          * start looking at them */
5420         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5421         if (IS_ERR(handle))
5422                 goto out;
5423         inode->i_mtime = inode->i_ctime = current_time(inode);
5424         ext4_mark_inode_dirty(handle, inode);
5425         ext4_journal_stop(handle);
5426
5427 out:
5428         return dquot_quota_off(sb, type);
5429 }
5430
5431 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5432  * acquiring the locks... As quota files are never truncated and quota code
5433  * itself serializes the operations (and no one else should touch the files)
5434  * we don't have to be afraid of races */
5435 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5436                                size_t len, loff_t off)
5437 {
5438         struct inode *inode = sb_dqopt(sb)->files[type];
5439         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5440         int offset = off & (sb->s_blocksize - 1);
5441         int tocopy;
5442         size_t toread;
5443         struct buffer_head *bh;
5444         loff_t i_size = i_size_read(inode);
5445
5446         if (off > i_size)
5447                 return 0;
5448         if (off+len > i_size)
5449                 len = i_size-off;
5450         toread = len;
5451         while (toread > 0) {
5452                 tocopy = sb->s_blocksize - offset < toread ?
5453                                 sb->s_blocksize - offset : toread;
5454                 bh = ext4_bread(NULL, inode, blk, 0);
5455                 if (IS_ERR(bh))
5456                         return PTR_ERR(bh);
5457                 if (!bh)        /* A hole? */
5458                         memset(data, 0, tocopy);
5459                 else
5460                         memcpy(data, bh->b_data+offset, tocopy);
5461                 brelse(bh);
5462                 offset = 0;
5463                 toread -= tocopy;
5464                 data += tocopy;
5465                 blk++;
5466         }
5467         return len;
5468 }
5469
5470 /* Write to quotafile (we know the transaction is already started and has
5471  * enough credits) */
5472 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5473                                 const char *data, size_t len, loff_t off)
5474 {
5475         struct inode *inode = sb_dqopt(sb)->files[type];
5476         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5477         int err, offset = off & (sb->s_blocksize - 1);
5478         int retries = 0;
5479         struct buffer_head *bh;
5480         handle_t *handle = journal_current_handle();
5481
5482         if (EXT4_SB(sb)->s_journal && !handle) {
5483                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5484                         " cancelled because transaction is not started",
5485                         (unsigned long long)off, (unsigned long long)len);
5486                 return -EIO;
5487         }
5488         /*
5489          * Since we account only one data block in transaction credits,
5490          * then it is impossible to cross a block boundary.
5491          */
5492         if (sb->s_blocksize - offset < len) {
5493                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5494                         " cancelled because not block aligned",
5495                         (unsigned long long)off, (unsigned long long)len);
5496                 return -EIO;
5497         }
5498
5499         do {
5500                 bh = ext4_bread(handle, inode, blk,
5501                                 EXT4_GET_BLOCKS_CREATE |
5502                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5503         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5504                  ext4_should_retry_alloc(inode->i_sb, &retries));
5505         if (IS_ERR(bh))
5506                 return PTR_ERR(bh);
5507         if (!bh)
5508                 goto out;
5509         BUFFER_TRACE(bh, "get write access");
5510         err = ext4_journal_get_write_access(handle, bh);
5511         if (err) {
5512                 brelse(bh);
5513                 return err;
5514         }
5515         lock_buffer(bh);
5516         memcpy(bh->b_data+offset, data, len);
5517         flush_dcache_page(bh->b_page);
5518         unlock_buffer(bh);
5519         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5520         brelse(bh);
5521 out:
5522         if (inode->i_size < off + len) {
5523                 i_size_write(inode, off + len);
5524                 EXT4_I(inode)->i_disksize = inode->i_size;
5525                 ext4_mark_inode_dirty(handle, inode);
5526         }
5527         return len;
5528 }
5529
5530 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5531 {
5532         const struct quota_format_ops   *ops;
5533
5534         if (!sb_has_quota_loaded(sb, qid->type))
5535                 return -ESRCH;
5536         ops = sb_dqopt(sb)->ops[qid->type];
5537         if (!ops || !ops->get_next_id)
5538                 return -ENOSYS;
5539         return dquot_get_next_id(sb, qid);
5540 }
5541 #endif
5542
5543 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5544                        const char *dev_name, void *data)
5545 {
5546         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5547 }
5548
5549 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5550 static inline void register_as_ext2(void)
5551 {
5552         int err = register_filesystem(&ext2_fs_type);
5553         if (err)
5554                 printk(KERN_WARNING
5555                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5556 }
5557
5558 static inline void unregister_as_ext2(void)
5559 {
5560         unregister_filesystem(&ext2_fs_type);
5561 }
5562
5563 static inline int ext2_feature_set_ok(struct super_block *sb)
5564 {
5565         if (ext4_has_unknown_ext2_incompat_features(sb))
5566                 return 0;
5567         if (sb->s_flags & MS_RDONLY)
5568                 return 1;
5569         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5570                 return 0;
5571         return 1;
5572 }
5573 #else
5574 static inline void register_as_ext2(void) { }
5575 static inline void unregister_as_ext2(void) { }
5576 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5577 #endif
5578
5579 static inline void register_as_ext3(void)
5580 {
5581         int err = register_filesystem(&ext3_fs_type);
5582         if (err)
5583                 printk(KERN_WARNING
5584                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5585 }
5586
5587 static inline void unregister_as_ext3(void)
5588 {
5589         unregister_filesystem(&ext3_fs_type);
5590 }
5591
5592 static inline int ext3_feature_set_ok(struct super_block *sb)
5593 {
5594         if (ext4_has_unknown_ext3_incompat_features(sb))
5595                 return 0;
5596         if (!ext4_has_feature_journal(sb))
5597                 return 0;
5598         if (sb->s_flags & MS_RDONLY)
5599                 return 1;
5600         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5601                 return 0;
5602         return 1;
5603 }
5604
5605 static struct file_system_type ext4_fs_type = {
5606         .owner          = THIS_MODULE,
5607         .name           = "ext4",
5608         .mount          = ext4_mount,
5609         .kill_sb        = kill_block_super,
5610         .fs_flags       = FS_REQUIRES_DEV,
5611 };
5612 MODULE_ALIAS_FS("ext4");
5613
5614 /* Shared across all ext4 file systems */
5615 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5616
5617 static int __init ext4_init_fs(void)
5618 {
5619         int i, err;
5620
5621         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5622         ext4_li_info = NULL;
5623         mutex_init(&ext4_li_mtx);
5624
5625         /* Build-time check for flags consistency */
5626         ext4_check_flag_values();
5627
5628         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5629                 init_waitqueue_head(&ext4__ioend_wq[i]);
5630
5631         err = ext4_init_es();
5632         if (err)
5633                 return err;
5634
5635         err = ext4_init_pageio();
5636         if (err)
5637                 goto out5;
5638
5639         err = ext4_init_system_zone();
5640         if (err)
5641                 goto out4;
5642
5643         err = ext4_init_sysfs();
5644         if (err)
5645                 goto out3;
5646
5647         err = ext4_init_mballoc();
5648         if (err)
5649                 goto out2;
5650         err = init_inodecache();
5651         if (err)
5652                 goto out1;
5653         register_as_ext3();
5654         register_as_ext2();
5655         err = register_filesystem(&ext4_fs_type);
5656         if (err)
5657                 goto out;
5658
5659         return 0;
5660 out:
5661         unregister_as_ext2();
5662         unregister_as_ext3();
5663         destroy_inodecache();
5664 out1:
5665         ext4_exit_mballoc();
5666 out2:
5667         ext4_exit_sysfs();
5668 out3:
5669         ext4_exit_system_zone();
5670 out4:
5671         ext4_exit_pageio();
5672 out5:
5673         ext4_exit_es();
5674
5675         return err;
5676 }
5677
5678 static void __exit ext4_exit_fs(void)
5679 {
5680         ext4_destroy_lazyinit_thread();
5681         unregister_as_ext2();
5682         unregister_as_ext3();
5683         unregister_filesystem(&ext4_fs_type);
5684         destroy_inodecache();
5685         ext4_exit_mballoc();
5686         ext4_exit_sysfs();
5687         ext4_exit_system_zone();
5688         ext4_exit_pageio();
5689         ext4_exit_es();
5690 }
5691
5692 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5693 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5694 MODULE_LICENSE("GPL");
5695 module_init(ext4_init_fs)
5696 module_exit(ext4_exit_fs)