Merge tag 'for-linus-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
[linux-2.6-microblaze.git] / fs / ext4 / super.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/cleancache.h>
43 #include <linux/uaccess.h>
44 #include <linux/iversion.h>
45 #include <linux/unicode.h>
46
47 #include <linux/kthread.h>
48 #include <linux/freezer.h>
49
50 #include "ext4.h"
51 #include "ext4_extents.h"       /* Needed for trace points definition */
52 #include "ext4_jbd2.h"
53 #include "xattr.h"
54 #include "acl.h"
55 #include "mballoc.h"
56 #include "fsmap.h"
57
58 #define CREATE_TRACE_POINTS
59 #include <trace/events/ext4.h>
60
61 static struct ext4_lazy_init *ext4_li_info;
62 static struct mutex ext4_li_mtx;
63 static struct ratelimit_state ext4_mount_msg_ratelimit;
64
65 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
66                              unsigned long journal_devnum);
67 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
68 static int ext4_commit_super(struct super_block *sb, int sync);
69 static void ext4_mark_recovery_complete(struct super_block *sb,
70                                         struct ext4_super_block *es);
71 static void ext4_clear_journal_err(struct super_block *sb,
72                                    struct ext4_super_block *es);
73 static int ext4_sync_fs(struct super_block *sb, int wait);
74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
76 static int ext4_unfreeze(struct super_block *sb);
77 static int ext4_freeze(struct super_block *sb);
78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
79                        const char *dev_name, void *data);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
83 static void ext4_destroy_lazyinit_thread(void);
84 static void ext4_unregister_li_request(struct super_block *sb);
85 static void ext4_clear_request_list(void);
86 static struct inode *ext4_get_journal_inode(struct super_block *sb,
87                                             unsigned int journal_inum);
88
89 /*
90  * Lock ordering
91  *
92  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
93  * i_mmap_rwsem (inode->i_mmap_rwsem)!
94  *
95  * page fault path:
96  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
97  *   page lock -> i_data_sem (rw)
98  *
99  * buffered write path:
100  * sb_start_write -> i_mutex -> mmap_sem
101  * sb_start_write -> i_mutex -> transaction start -> page lock ->
102  *   i_data_sem (rw)
103  *
104  * truncate:
105  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
106  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
107  *   i_data_sem (rw)
108  *
109  * direct IO:
110  * sb_start_write -> i_mutex -> mmap_sem
111  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
112  *
113  * writepages:
114  * transaction start -> page lock(s) -> i_data_sem (rw)
115  */
116
117 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
118 static struct file_system_type ext2_fs_type = {
119         .owner          = THIS_MODULE,
120         .name           = "ext2",
121         .mount          = ext4_mount,
122         .kill_sb        = kill_block_super,
123         .fs_flags       = FS_REQUIRES_DEV,
124 };
125 MODULE_ALIAS_FS("ext2");
126 MODULE_ALIAS("ext2");
127 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
128 #else
129 #define IS_EXT2_SB(sb) (0)
130 #endif
131
132
133 static struct file_system_type ext3_fs_type = {
134         .owner          = THIS_MODULE,
135         .name           = "ext3",
136         .mount          = ext4_mount,
137         .kill_sb        = kill_block_super,
138         .fs_flags       = FS_REQUIRES_DEV,
139 };
140 MODULE_ALIAS_FS("ext3");
141 MODULE_ALIAS("ext3");
142 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
143
144 /*
145  * This works like sb_bread() except it uses ERR_PTR for error
146  * returns.  Currently with sb_bread it's impossible to distinguish
147  * between ENOMEM and EIO situations (since both result in a NULL
148  * return.
149  */
150 struct buffer_head *
151 ext4_sb_bread(struct super_block *sb, sector_t block, int op_flags)
152 {
153         struct buffer_head *bh = sb_getblk(sb, block);
154
155         if (bh == NULL)
156                 return ERR_PTR(-ENOMEM);
157         if (buffer_uptodate(bh))
158                 return bh;
159         ll_rw_block(REQ_OP_READ, REQ_META | op_flags, 1, &bh);
160         wait_on_buffer(bh);
161         if (buffer_uptodate(bh))
162                 return bh;
163         put_bh(bh);
164         return ERR_PTR(-EIO);
165 }
166
167 static int ext4_verify_csum_type(struct super_block *sb,
168                                  struct ext4_super_block *es)
169 {
170         if (!ext4_has_feature_metadata_csum(sb))
171                 return 1;
172
173         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
174 }
175
176 static __le32 ext4_superblock_csum(struct super_block *sb,
177                                    struct ext4_super_block *es)
178 {
179         struct ext4_sb_info *sbi = EXT4_SB(sb);
180         int offset = offsetof(struct ext4_super_block, s_checksum);
181         __u32 csum;
182
183         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
184
185         return cpu_to_le32(csum);
186 }
187
188 static int ext4_superblock_csum_verify(struct super_block *sb,
189                                        struct ext4_super_block *es)
190 {
191         if (!ext4_has_metadata_csum(sb))
192                 return 1;
193
194         return es->s_checksum == ext4_superblock_csum(sb, es);
195 }
196
197 void ext4_superblock_csum_set(struct super_block *sb)
198 {
199         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
200
201         if (!ext4_has_metadata_csum(sb))
202                 return;
203
204         es->s_checksum = ext4_superblock_csum(sb, es);
205 }
206
207 void *ext4_kvmalloc(size_t size, gfp_t flags)
208 {
209         void *ret;
210
211         ret = kmalloc(size, flags | __GFP_NOWARN);
212         if (!ret)
213                 ret = __vmalloc(size, flags, PAGE_KERNEL);
214         return ret;
215 }
216
217 void *ext4_kvzalloc(size_t size, gfp_t flags)
218 {
219         void *ret;
220
221         ret = kzalloc(size, flags | __GFP_NOWARN);
222         if (!ret)
223                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
224         return ret;
225 }
226
227 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
228                                struct ext4_group_desc *bg)
229 {
230         return le32_to_cpu(bg->bg_block_bitmap_lo) |
231                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
232                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
233 }
234
235 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
236                                struct ext4_group_desc *bg)
237 {
238         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
239                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
240                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
241 }
242
243 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
244                               struct ext4_group_desc *bg)
245 {
246         return le32_to_cpu(bg->bg_inode_table_lo) |
247                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
248                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
249 }
250
251 __u32 ext4_free_group_clusters(struct super_block *sb,
252                                struct ext4_group_desc *bg)
253 {
254         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
255                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
256                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
257 }
258
259 __u32 ext4_free_inodes_count(struct super_block *sb,
260                               struct ext4_group_desc *bg)
261 {
262         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
263                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
264                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
265 }
266
267 __u32 ext4_used_dirs_count(struct super_block *sb,
268                               struct ext4_group_desc *bg)
269 {
270         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
271                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
272                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
273 }
274
275 __u32 ext4_itable_unused_count(struct super_block *sb,
276                               struct ext4_group_desc *bg)
277 {
278         return le16_to_cpu(bg->bg_itable_unused_lo) |
279                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
280                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
281 }
282
283 void ext4_block_bitmap_set(struct super_block *sb,
284                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
285 {
286         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
287         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
288                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
289 }
290
291 void ext4_inode_bitmap_set(struct super_block *sb,
292                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
293 {
294         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
295         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
296                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
297 }
298
299 void ext4_inode_table_set(struct super_block *sb,
300                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
301 {
302         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
303         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
304                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
305 }
306
307 void ext4_free_group_clusters_set(struct super_block *sb,
308                                   struct ext4_group_desc *bg, __u32 count)
309 {
310         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
311         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
312                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
313 }
314
315 void ext4_free_inodes_set(struct super_block *sb,
316                           struct ext4_group_desc *bg, __u32 count)
317 {
318         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
319         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
320                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
321 }
322
323 void ext4_used_dirs_set(struct super_block *sb,
324                           struct ext4_group_desc *bg, __u32 count)
325 {
326         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
327         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
328                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
329 }
330
331 void ext4_itable_unused_set(struct super_block *sb,
332                           struct ext4_group_desc *bg, __u32 count)
333 {
334         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
335         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
336                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
337 }
338
339 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
340 {
341         time64_t now = ktime_get_real_seconds();
342
343         now = clamp_val(now, 0, (1ull << 40) - 1);
344
345         *lo = cpu_to_le32(lower_32_bits(now));
346         *hi = upper_32_bits(now);
347 }
348
349 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
350 {
351         return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
352 }
353 #define ext4_update_tstamp(es, tstamp) \
354         __ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
355 #define ext4_get_tstamp(es, tstamp) \
356         __ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
357
358 static void __save_error_info(struct super_block *sb, const char *func,
359                             unsigned int line)
360 {
361         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
362
363         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
364         if (bdev_read_only(sb->s_bdev))
365                 return;
366         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
367         ext4_update_tstamp(es, s_last_error_time);
368         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
369         es->s_last_error_line = cpu_to_le32(line);
370         if (!es->s_first_error_time) {
371                 es->s_first_error_time = es->s_last_error_time;
372                 es->s_first_error_time_hi = es->s_last_error_time_hi;
373                 strncpy(es->s_first_error_func, func,
374                         sizeof(es->s_first_error_func));
375                 es->s_first_error_line = cpu_to_le32(line);
376                 es->s_first_error_ino = es->s_last_error_ino;
377                 es->s_first_error_block = es->s_last_error_block;
378         }
379         /*
380          * Start the daily error reporting function if it hasn't been
381          * started already
382          */
383         if (!es->s_error_count)
384                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
385         le32_add_cpu(&es->s_error_count, 1);
386 }
387
388 static void save_error_info(struct super_block *sb, const char *func,
389                             unsigned int line)
390 {
391         __save_error_info(sb, func, line);
392         ext4_commit_super(sb, 1);
393 }
394
395 /*
396  * The del_gendisk() function uninitializes the disk-specific data
397  * structures, including the bdi structure, without telling anyone
398  * else.  Once this happens, any attempt to call mark_buffer_dirty()
399  * (for example, by ext4_commit_super), will cause a kernel OOPS.
400  * This is a kludge to prevent these oops until we can put in a proper
401  * hook in del_gendisk() to inform the VFS and file system layers.
402  */
403 static int block_device_ejected(struct super_block *sb)
404 {
405         struct inode *bd_inode = sb->s_bdev->bd_inode;
406         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
407
408         return bdi->dev == NULL;
409 }
410
411 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
412 {
413         struct super_block              *sb = journal->j_private;
414         struct ext4_sb_info             *sbi = EXT4_SB(sb);
415         int                             error = is_journal_aborted(journal);
416         struct ext4_journal_cb_entry    *jce;
417
418         BUG_ON(txn->t_state == T_FINISHED);
419
420         ext4_process_freed_data(sb, txn->t_tid);
421
422         spin_lock(&sbi->s_md_lock);
423         while (!list_empty(&txn->t_private_list)) {
424                 jce = list_entry(txn->t_private_list.next,
425                                  struct ext4_journal_cb_entry, jce_list);
426                 list_del_init(&jce->jce_list);
427                 spin_unlock(&sbi->s_md_lock);
428                 jce->jce_func(sb, jce, error);
429                 spin_lock(&sbi->s_md_lock);
430         }
431         spin_unlock(&sbi->s_md_lock);
432 }
433
434 static bool system_going_down(void)
435 {
436         return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
437                 || system_state == SYSTEM_RESTART;
438 }
439
440 /* Deal with the reporting of failure conditions on a filesystem such as
441  * inconsistencies detected or read IO failures.
442  *
443  * On ext2, we can store the error state of the filesystem in the
444  * superblock.  That is not possible on ext4, because we may have other
445  * write ordering constraints on the superblock which prevent us from
446  * writing it out straight away; and given that the journal is about to
447  * be aborted, we can't rely on the current, or future, transactions to
448  * write out the superblock safely.
449  *
450  * We'll just use the jbd2_journal_abort() error code to record an error in
451  * the journal instead.  On recovery, the journal will complain about
452  * that error until we've noted it down and cleared it.
453  */
454
455 static void ext4_handle_error(struct super_block *sb)
456 {
457         if (test_opt(sb, WARN_ON_ERROR))
458                 WARN_ON_ONCE(1);
459
460         if (sb_rdonly(sb))
461                 return;
462
463         if (!test_opt(sb, ERRORS_CONT)) {
464                 journal_t *journal = EXT4_SB(sb)->s_journal;
465
466                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
467                 if (journal)
468                         jbd2_journal_abort(journal, -EIO);
469         }
470         /*
471          * We force ERRORS_RO behavior when system is rebooting. Otherwise we
472          * could panic during 'reboot -f' as the underlying device got already
473          * disabled.
474          */
475         if (test_opt(sb, ERRORS_RO) || system_going_down()) {
476                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
477                 /*
478                  * Make sure updated value of ->s_mount_flags will be visible
479                  * before ->s_flags update
480                  */
481                 smp_wmb();
482                 sb->s_flags |= SB_RDONLY;
483         } else if (test_opt(sb, ERRORS_PANIC)) {
484                 if (EXT4_SB(sb)->s_journal &&
485                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
486                         return;
487                 panic("EXT4-fs (device %s): panic forced after error\n",
488                         sb->s_id);
489         }
490 }
491
492 #define ext4_error_ratelimit(sb)                                        \
493                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
494                              "EXT4-fs error")
495
496 void __ext4_error(struct super_block *sb, const char *function,
497                   unsigned int line, const char *fmt, ...)
498 {
499         struct va_format vaf;
500         va_list args;
501
502         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
503                 return;
504
505         trace_ext4_error(sb, function, line);
506         if (ext4_error_ratelimit(sb)) {
507                 va_start(args, fmt);
508                 vaf.fmt = fmt;
509                 vaf.va = &args;
510                 printk(KERN_CRIT
511                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
512                        sb->s_id, function, line, current->comm, &vaf);
513                 va_end(args);
514         }
515         save_error_info(sb, function, line);
516         ext4_handle_error(sb);
517 }
518
519 void __ext4_error_inode(struct inode *inode, const char *function,
520                         unsigned int line, ext4_fsblk_t block,
521                         const char *fmt, ...)
522 {
523         va_list args;
524         struct va_format vaf;
525         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
526
527         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
528                 return;
529
530         trace_ext4_error(inode->i_sb, function, line);
531         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
532         es->s_last_error_block = cpu_to_le64(block);
533         if (ext4_error_ratelimit(inode->i_sb)) {
534                 va_start(args, fmt);
535                 vaf.fmt = fmt;
536                 vaf.va = &args;
537                 if (block)
538                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
539                                "inode #%lu: block %llu: comm %s: %pV\n",
540                                inode->i_sb->s_id, function, line, inode->i_ino,
541                                block, current->comm, &vaf);
542                 else
543                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
544                                "inode #%lu: comm %s: %pV\n",
545                                inode->i_sb->s_id, function, line, inode->i_ino,
546                                current->comm, &vaf);
547                 va_end(args);
548         }
549         save_error_info(inode->i_sb, function, line);
550         ext4_handle_error(inode->i_sb);
551 }
552
553 void __ext4_error_file(struct file *file, const char *function,
554                        unsigned int line, ext4_fsblk_t block,
555                        const char *fmt, ...)
556 {
557         va_list args;
558         struct va_format vaf;
559         struct ext4_super_block *es;
560         struct inode *inode = file_inode(file);
561         char pathname[80], *path;
562
563         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
564                 return;
565
566         trace_ext4_error(inode->i_sb, function, line);
567         es = EXT4_SB(inode->i_sb)->s_es;
568         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
569         if (ext4_error_ratelimit(inode->i_sb)) {
570                 path = file_path(file, pathname, sizeof(pathname));
571                 if (IS_ERR(path))
572                         path = "(unknown)";
573                 va_start(args, fmt);
574                 vaf.fmt = fmt;
575                 vaf.va = &args;
576                 if (block)
577                         printk(KERN_CRIT
578                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
579                                "block %llu: comm %s: path %s: %pV\n",
580                                inode->i_sb->s_id, function, line, inode->i_ino,
581                                block, current->comm, path, &vaf);
582                 else
583                         printk(KERN_CRIT
584                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
585                                "comm %s: path %s: %pV\n",
586                                inode->i_sb->s_id, function, line, inode->i_ino,
587                                current->comm, path, &vaf);
588                 va_end(args);
589         }
590         save_error_info(inode->i_sb, function, line);
591         ext4_handle_error(inode->i_sb);
592 }
593
594 const char *ext4_decode_error(struct super_block *sb, int errno,
595                               char nbuf[16])
596 {
597         char *errstr = NULL;
598
599         switch (errno) {
600         case -EFSCORRUPTED:
601                 errstr = "Corrupt filesystem";
602                 break;
603         case -EFSBADCRC:
604                 errstr = "Filesystem failed CRC";
605                 break;
606         case -EIO:
607                 errstr = "IO failure";
608                 break;
609         case -ENOMEM:
610                 errstr = "Out of memory";
611                 break;
612         case -EROFS:
613                 if (!sb || (EXT4_SB(sb)->s_journal &&
614                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
615                         errstr = "Journal has aborted";
616                 else
617                         errstr = "Readonly filesystem";
618                 break;
619         default:
620                 /* If the caller passed in an extra buffer for unknown
621                  * errors, textualise them now.  Else we just return
622                  * NULL. */
623                 if (nbuf) {
624                         /* Check for truncated error codes... */
625                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
626                                 errstr = nbuf;
627                 }
628                 break;
629         }
630
631         return errstr;
632 }
633
634 /* __ext4_std_error decodes expected errors from journaling functions
635  * automatically and invokes the appropriate error response.  */
636
637 void __ext4_std_error(struct super_block *sb, const char *function,
638                       unsigned int line, int errno)
639 {
640         char nbuf[16];
641         const char *errstr;
642
643         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
644                 return;
645
646         /* Special case: if the error is EROFS, and we're not already
647          * inside a transaction, then there's really no point in logging
648          * an error. */
649         if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
650                 return;
651
652         if (ext4_error_ratelimit(sb)) {
653                 errstr = ext4_decode_error(sb, errno, nbuf);
654                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
655                        sb->s_id, function, line, errstr);
656         }
657
658         save_error_info(sb, function, line);
659         ext4_handle_error(sb);
660 }
661
662 /*
663  * ext4_abort is a much stronger failure handler than ext4_error.  The
664  * abort function may be used to deal with unrecoverable failures such
665  * as journal IO errors or ENOMEM at a critical moment in log management.
666  *
667  * We unconditionally force the filesystem into an ABORT|READONLY state,
668  * unless the error response on the fs has been set to panic in which
669  * case we take the easy way out and panic immediately.
670  */
671
672 void __ext4_abort(struct super_block *sb, const char *function,
673                 unsigned int line, const char *fmt, ...)
674 {
675         struct va_format vaf;
676         va_list args;
677
678         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
679                 return;
680
681         save_error_info(sb, function, line);
682         va_start(args, fmt);
683         vaf.fmt = fmt;
684         vaf.va = &args;
685         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
686                sb->s_id, function, line, &vaf);
687         va_end(args);
688
689         if (sb_rdonly(sb) == 0) {
690                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
691                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
692                 /*
693                  * Make sure updated value of ->s_mount_flags will be visible
694                  * before ->s_flags update
695                  */
696                 smp_wmb();
697                 sb->s_flags |= SB_RDONLY;
698                 if (EXT4_SB(sb)->s_journal)
699                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
700                 save_error_info(sb, function, line);
701         }
702         if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
703                 if (EXT4_SB(sb)->s_journal &&
704                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
705                         return;
706                 panic("EXT4-fs panic from previous error\n");
707         }
708 }
709
710 void __ext4_msg(struct super_block *sb,
711                 const char *prefix, const char *fmt, ...)
712 {
713         struct va_format vaf;
714         va_list args;
715
716         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
717                 return;
718
719         va_start(args, fmt);
720         vaf.fmt = fmt;
721         vaf.va = &args;
722         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
723         va_end(args);
724 }
725
726 #define ext4_warning_ratelimit(sb)                                      \
727                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
728                              "EXT4-fs warning")
729
730 void __ext4_warning(struct super_block *sb, const char *function,
731                     unsigned int line, const char *fmt, ...)
732 {
733         struct va_format vaf;
734         va_list args;
735
736         if (!ext4_warning_ratelimit(sb))
737                 return;
738
739         va_start(args, fmt);
740         vaf.fmt = fmt;
741         vaf.va = &args;
742         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
743                sb->s_id, function, line, &vaf);
744         va_end(args);
745 }
746
747 void __ext4_warning_inode(const struct inode *inode, const char *function,
748                           unsigned int line, const char *fmt, ...)
749 {
750         struct va_format vaf;
751         va_list args;
752
753         if (!ext4_warning_ratelimit(inode->i_sb))
754                 return;
755
756         va_start(args, fmt);
757         vaf.fmt = fmt;
758         vaf.va = &args;
759         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
760                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
761                function, line, inode->i_ino, current->comm, &vaf);
762         va_end(args);
763 }
764
765 void __ext4_grp_locked_error(const char *function, unsigned int line,
766                              struct super_block *sb, ext4_group_t grp,
767                              unsigned long ino, ext4_fsblk_t block,
768                              const char *fmt, ...)
769 __releases(bitlock)
770 __acquires(bitlock)
771 {
772         struct va_format vaf;
773         va_list args;
774         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
775
776         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
777                 return;
778
779         trace_ext4_error(sb, function, line);
780         es->s_last_error_ino = cpu_to_le32(ino);
781         es->s_last_error_block = cpu_to_le64(block);
782         __save_error_info(sb, function, line);
783
784         if (ext4_error_ratelimit(sb)) {
785                 va_start(args, fmt);
786                 vaf.fmt = fmt;
787                 vaf.va = &args;
788                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
789                        sb->s_id, function, line, grp);
790                 if (ino)
791                         printk(KERN_CONT "inode %lu: ", ino);
792                 if (block)
793                         printk(KERN_CONT "block %llu:",
794                                (unsigned long long) block);
795                 printk(KERN_CONT "%pV\n", &vaf);
796                 va_end(args);
797         }
798
799         if (test_opt(sb, WARN_ON_ERROR))
800                 WARN_ON_ONCE(1);
801
802         if (test_opt(sb, ERRORS_CONT)) {
803                 ext4_commit_super(sb, 0);
804                 return;
805         }
806
807         ext4_unlock_group(sb, grp);
808         ext4_commit_super(sb, 1);
809         ext4_handle_error(sb);
810         /*
811          * We only get here in the ERRORS_RO case; relocking the group
812          * may be dangerous, but nothing bad will happen since the
813          * filesystem will have already been marked read/only and the
814          * journal has been aborted.  We return 1 as a hint to callers
815          * who might what to use the return value from
816          * ext4_grp_locked_error() to distinguish between the
817          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
818          * aggressively from the ext4 function in question, with a
819          * more appropriate error code.
820          */
821         ext4_lock_group(sb, grp);
822         return;
823 }
824
825 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
826                                      ext4_group_t group,
827                                      unsigned int flags)
828 {
829         struct ext4_sb_info *sbi = EXT4_SB(sb);
830         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
831         struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
832         int ret;
833
834         if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
835                 ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
836                                             &grp->bb_state);
837                 if (!ret)
838                         percpu_counter_sub(&sbi->s_freeclusters_counter,
839                                            grp->bb_free);
840         }
841
842         if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
843                 ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
844                                             &grp->bb_state);
845                 if (!ret && gdp) {
846                         int count;
847
848                         count = ext4_free_inodes_count(sb, gdp);
849                         percpu_counter_sub(&sbi->s_freeinodes_counter,
850                                            count);
851                 }
852         }
853 }
854
855 void ext4_update_dynamic_rev(struct super_block *sb)
856 {
857         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
858
859         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
860                 return;
861
862         ext4_warning(sb,
863                      "updating to rev %d because of new feature flag, "
864                      "running e2fsck is recommended",
865                      EXT4_DYNAMIC_REV);
866
867         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
868         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
869         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
870         /* leave es->s_feature_*compat flags alone */
871         /* es->s_uuid will be set by e2fsck if empty */
872
873         /*
874          * The rest of the superblock fields should be zero, and if not it
875          * means they are likely already in use, so leave them alone.  We
876          * can leave it up to e2fsck to clean up any inconsistencies there.
877          */
878 }
879
880 /*
881  * Open the external journal device
882  */
883 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
884 {
885         struct block_device *bdev;
886         char b[BDEVNAME_SIZE];
887
888         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
889         if (IS_ERR(bdev))
890                 goto fail;
891         return bdev;
892
893 fail:
894         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
895                         __bdevname(dev, b), PTR_ERR(bdev));
896         return NULL;
897 }
898
899 /*
900  * Release the journal device
901  */
902 static void ext4_blkdev_put(struct block_device *bdev)
903 {
904         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
905 }
906
907 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
908 {
909         struct block_device *bdev;
910         bdev = sbi->journal_bdev;
911         if (bdev) {
912                 ext4_blkdev_put(bdev);
913                 sbi->journal_bdev = NULL;
914         }
915 }
916
917 static inline struct inode *orphan_list_entry(struct list_head *l)
918 {
919         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
920 }
921
922 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
923 {
924         struct list_head *l;
925
926         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
927                  le32_to_cpu(sbi->s_es->s_last_orphan));
928
929         printk(KERN_ERR "sb_info orphan list:\n");
930         list_for_each(l, &sbi->s_orphan) {
931                 struct inode *inode = orphan_list_entry(l);
932                 printk(KERN_ERR "  "
933                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
934                        inode->i_sb->s_id, inode->i_ino, inode,
935                        inode->i_mode, inode->i_nlink,
936                        NEXT_ORPHAN(inode));
937         }
938 }
939
940 #ifdef CONFIG_QUOTA
941 static int ext4_quota_off(struct super_block *sb, int type);
942
943 static inline void ext4_quota_off_umount(struct super_block *sb)
944 {
945         int type;
946
947         /* Use our quota_off function to clear inode flags etc. */
948         for (type = 0; type < EXT4_MAXQUOTAS; type++)
949                 ext4_quota_off(sb, type);
950 }
951
952 /*
953  * This is a helper function which is used in the mount/remount
954  * codepaths (which holds s_umount) to fetch the quota file name.
955  */
956 static inline char *get_qf_name(struct super_block *sb,
957                                 struct ext4_sb_info *sbi,
958                                 int type)
959 {
960         return rcu_dereference_protected(sbi->s_qf_names[type],
961                                          lockdep_is_held(&sb->s_umount));
962 }
963 #else
964 static inline void ext4_quota_off_umount(struct super_block *sb)
965 {
966 }
967 #endif
968
969 static void ext4_put_super(struct super_block *sb)
970 {
971         struct ext4_sb_info *sbi = EXT4_SB(sb);
972         struct ext4_super_block *es = sbi->s_es;
973         int aborted = 0;
974         int i, err;
975
976         ext4_unregister_li_request(sb);
977         ext4_quota_off_umount(sb);
978
979         destroy_workqueue(sbi->rsv_conversion_wq);
980
981         if (sbi->s_journal) {
982                 aborted = is_journal_aborted(sbi->s_journal);
983                 err = jbd2_journal_destroy(sbi->s_journal);
984                 sbi->s_journal = NULL;
985                 if ((err < 0) && !aborted)
986                         ext4_abort(sb, "Couldn't clean up the journal");
987         }
988
989         ext4_unregister_sysfs(sb);
990         ext4_es_unregister_shrinker(sbi);
991         del_timer_sync(&sbi->s_err_report);
992         ext4_release_system_zone(sb);
993         ext4_mb_release(sb);
994         ext4_ext_release(sb);
995
996         if (!sb_rdonly(sb) && !aborted) {
997                 ext4_clear_feature_journal_needs_recovery(sb);
998                 es->s_state = cpu_to_le16(sbi->s_mount_state);
999         }
1000         if (!sb_rdonly(sb))
1001                 ext4_commit_super(sb, 1);
1002
1003         for (i = 0; i < sbi->s_gdb_count; i++)
1004                 brelse(sbi->s_group_desc[i]);
1005         kvfree(sbi->s_group_desc);
1006         kvfree(sbi->s_flex_groups);
1007         percpu_counter_destroy(&sbi->s_freeclusters_counter);
1008         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1009         percpu_counter_destroy(&sbi->s_dirs_counter);
1010         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1011         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
1012 #ifdef CONFIG_QUOTA
1013         for (i = 0; i < EXT4_MAXQUOTAS; i++)
1014                 kfree(get_qf_name(sb, sbi, i));
1015 #endif
1016
1017         /* Debugging code just in case the in-memory inode orphan list
1018          * isn't empty.  The on-disk one can be non-empty if we've
1019          * detected an error and taken the fs readonly, but the
1020          * in-memory list had better be clean by this point. */
1021         if (!list_empty(&sbi->s_orphan))
1022                 dump_orphan_list(sb, sbi);
1023         J_ASSERT(list_empty(&sbi->s_orphan));
1024
1025         sync_blockdev(sb->s_bdev);
1026         invalidate_bdev(sb->s_bdev);
1027         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
1028                 /*
1029                  * Invalidate the journal device's buffers.  We don't want them
1030                  * floating about in memory - the physical journal device may
1031                  * hotswapped, and it breaks the `ro-after' testing code.
1032                  */
1033                 sync_blockdev(sbi->journal_bdev);
1034                 invalidate_bdev(sbi->journal_bdev);
1035                 ext4_blkdev_remove(sbi);
1036         }
1037
1038         ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1039         sbi->s_ea_inode_cache = NULL;
1040
1041         ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1042         sbi->s_ea_block_cache = NULL;
1043
1044         if (sbi->s_mmp_tsk)
1045                 kthread_stop(sbi->s_mmp_tsk);
1046         brelse(sbi->s_sbh);
1047         sb->s_fs_info = NULL;
1048         /*
1049          * Now that we are completely done shutting down the
1050          * superblock, we need to actually destroy the kobject.
1051          */
1052         kobject_put(&sbi->s_kobj);
1053         wait_for_completion(&sbi->s_kobj_unregister);
1054         if (sbi->s_chksum_driver)
1055                 crypto_free_shash(sbi->s_chksum_driver);
1056         kfree(sbi->s_blockgroup_lock);
1057         fs_put_dax(sbi->s_daxdev);
1058 #ifdef CONFIG_UNICODE
1059         utf8_unload(sbi->s_encoding);
1060 #endif
1061         kfree(sbi);
1062 }
1063
1064 static struct kmem_cache *ext4_inode_cachep;
1065
1066 /*
1067  * Called inside transaction, so use GFP_NOFS
1068  */
1069 static struct inode *ext4_alloc_inode(struct super_block *sb)
1070 {
1071         struct ext4_inode_info *ei;
1072
1073         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1074         if (!ei)
1075                 return NULL;
1076
1077         inode_set_iversion(&ei->vfs_inode, 1);
1078         spin_lock_init(&ei->i_raw_lock);
1079         INIT_LIST_HEAD(&ei->i_prealloc_list);
1080         spin_lock_init(&ei->i_prealloc_lock);
1081         ext4_es_init_tree(&ei->i_es_tree);
1082         rwlock_init(&ei->i_es_lock);
1083         INIT_LIST_HEAD(&ei->i_es_list);
1084         ei->i_es_all_nr = 0;
1085         ei->i_es_shk_nr = 0;
1086         ei->i_es_shrink_lblk = 0;
1087         ei->i_reserved_data_blocks = 0;
1088         ei->i_da_metadata_calc_len = 0;
1089         ei->i_da_metadata_calc_last_lblock = 0;
1090         spin_lock_init(&(ei->i_block_reservation_lock));
1091         ext4_init_pending_tree(&ei->i_pending_tree);
1092 #ifdef CONFIG_QUOTA
1093         ei->i_reserved_quota = 0;
1094         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1095 #endif
1096         ei->jinode = NULL;
1097         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1098         spin_lock_init(&ei->i_completed_io_lock);
1099         ei->i_sync_tid = 0;
1100         ei->i_datasync_tid = 0;
1101         atomic_set(&ei->i_unwritten, 0);
1102         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1103         return &ei->vfs_inode;
1104 }
1105
1106 static int ext4_drop_inode(struct inode *inode)
1107 {
1108         int drop = generic_drop_inode(inode);
1109
1110         if (!drop)
1111                 drop = fscrypt_drop_inode(inode);
1112
1113         trace_ext4_drop_inode(inode, drop);
1114         return drop;
1115 }
1116
1117 static void ext4_free_in_core_inode(struct inode *inode)
1118 {
1119         fscrypt_free_inode(inode);
1120         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1121 }
1122
1123 static void ext4_destroy_inode(struct inode *inode)
1124 {
1125         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1126                 ext4_msg(inode->i_sb, KERN_ERR,
1127                          "Inode %lu (%p): orphan list check failed!",
1128                          inode->i_ino, EXT4_I(inode));
1129                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1130                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
1131                                 true);
1132                 dump_stack();
1133         }
1134 }
1135
1136 static void init_once(void *foo)
1137 {
1138         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1139
1140         INIT_LIST_HEAD(&ei->i_orphan);
1141         init_rwsem(&ei->xattr_sem);
1142         init_rwsem(&ei->i_data_sem);
1143         init_rwsem(&ei->i_mmap_sem);
1144         inode_init_once(&ei->vfs_inode);
1145 }
1146
1147 static int __init init_inodecache(void)
1148 {
1149         ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1150                                 sizeof(struct ext4_inode_info), 0,
1151                                 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1152                                         SLAB_ACCOUNT),
1153                                 offsetof(struct ext4_inode_info, i_data),
1154                                 sizeof_field(struct ext4_inode_info, i_data),
1155                                 init_once);
1156         if (ext4_inode_cachep == NULL)
1157                 return -ENOMEM;
1158         return 0;
1159 }
1160
1161 static void destroy_inodecache(void)
1162 {
1163         /*
1164          * Make sure all delayed rcu free inodes are flushed before we
1165          * destroy cache.
1166          */
1167         rcu_barrier();
1168         kmem_cache_destroy(ext4_inode_cachep);
1169 }
1170
1171 void ext4_clear_inode(struct inode *inode)
1172 {
1173         invalidate_inode_buffers(inode);
1174         clear_inode(inode);
1175         dquot_drop(inode);
1176         ext4_discard_preallocations(inode);
1177         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1178         if (EXT4_I(inode)->jinode) {
1179                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1180                                                EXT4_I(inode)->jinode);
1181                 jbd2_free_inode(EXT4_I(inode)->jinode);
1182                 EXT4_I(inode)->jinode = NULL;
1183         }
1184         fscrypt_put_encryption_info(inode);
1185         fsverity_cleanup_inode(inode);
1186 }
1187
1188 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1189                                         u64 ino, u32 generation)
1190 {
1191         struct inode *inode;
1192
1193         /*
1194          * Currently we don't know the generation for parent directory, so
1195          * a generation of 0 means "accept any"
1196          */
1197         inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1198         if (IS_ERR(inode))
1199                 return ERR_CAST(inode);
1200         if (generation && inode->i_generation != generation) {
1201                 iput(inode);
1202                 return ERR_PTR(-ESTALE);
1203         }
1204
1205         return inode;
1206 }
1207
1208 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1209                                         int fh_len, int fh_type)
1210 {
1211         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1212                                     ext4_nfs_get_inode);
1213 }
1214
1215 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1216                                         int fh_len, int fh_type)
1217 {
1218         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1219                                     ext4_nfs_get_inode);
1220 }
1221
1222 static int ext4_nfs_commit_metadata(struct inode *inode)
1223 {
1224         struct writeback_control wbc = {
1225                 .sync_mode = WB_SYNC_ALL
1226         };
1227
1228         trace_ext4_nfs_commit_metadata(inode);
1229         return ext4_write_inode(inode, &wbc);
1230 }
1231
1232 /*
1233  * Try to release metadata pages (indirect blocks, directories) which are
1234  * mapped via the block device.  Since these pages could have journal heads
1235  * which would prevent try_to_free_buffers() from freeing them, we must use
1236  * jbd2 layer's try_to_free_buffers() function to release them.
1237  */
1238 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1239                                  gfp_t wait)
1240 {
1241         journal_t *journal = EXT4_SB(sb)->s_journal;
1242
1243         WARN_ON(PageChecked(page));
1244         if (!page_has_buffers(page))
1245                 return 0;
1246         if (journal)
1247                 return jbd2_journal_try_to_free_buffers(journal, page,
1248                                                 wait & ~__GFP_DIRECT_RECLAIM);
1249         return try_to_free_buffers(page);
1250 }
1251
1252 #ifdef CONFIG_FS_ENCRYPTION
1253 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1254 {
1255         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1256                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1257 }
1258
1259 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1260                                                         void *fs_data)
1261 {
1262         handle_t *handle = fs_data;
1263         int res, res2, credits, retries = 0;
1264
1265         /*
1266          * Encrypting the root directory is not allowed because e2fsck expects
1267          * lost+found to exist and be unencrypted, and encrypting the root
1268          * directory would imply encrypting the lost+found directory as well as
1269          * the filename "lost+found" itself.
1270          */
1271         if (inode->i_ino == EXT4_ROOT_INO)
1272                 return -EPERM;
1273
1274         if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1275                 return -EINVAL;
1276
1277         res = ext4_convert_inline_data(inode);
1278         if (res)
1279                 return res;
1280
1281         /*
1282          * If a journal handle was specified, then the encryption context is
1283          * being set on a new inode via inheritance and is part of a larger
1284          * transaction to create the inode.  Otherwise the encryption context is
1285          * being set on an existing inode in its own transaction.  Only in the
1286          * latter case should the "retry on ENOSPC" logic be used.
1287          */
1288
1289         if (handle) {
1290                 res = ext4_xattr_set_handle(handle, inode,
1291                                             EXT4_XATTR_INDEX_ENCRYPTION,
1292                                             EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1293                                             ctx, len, 0);
1294                 if (!res) {
1295                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1296                         ext4_clear_inode_state(inode,
1297                                         EXT4_STATE_MAY_INLINE_DATA);
1298                         /*
1299                          * Update inode->i_flags - S_ENCRYPTED will be enabled,
1300                          * S_DAX may be disabled
1301                          */
1302                         ext4_set_inode_flags(inode);
1303                 }
1304                 return res;
1305         }
1306
1307         res = dquot_initialize(inode);
1308         if (res)
1309                 return res;
1310 retry:
1311         res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1312                                      &credits);
1313         if (res)
1314                 return res;
1315
1316         handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1317         if (IS_ERR(handle))
1318                 return PTR_ERR(handle);
1319
1320         res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1321                                     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1322                                     ctx, len, 0);
1323         if (!res) {
1324                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1325                 /*
1326                  * Update inode->i_flags - S_ENCRYPTED will be enabled,
1327                  * S_DAX may be disabled
1328                  */
1329                 ext4_set_inode_flags(inode);
1330                 res = ext4_mark_inode_dirty(handle, inode);
1331                 if (res)
1332                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1333         }
1334         res2 = ext4_journal_stop(handle);
1335
1336         if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1337                 goto retry;
1338         if (!res)
1339                 res = res2;
1340         return res;
1341 }
1342
1343 static bool ext4_dummy_context(struct inode *inode)
1344 {
1345         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1346 }
1347
1348 static const struct fscrypt_operations ext4_cryptops = {
1349         .key_prefix             = "ext4:",
1350         .get_context            = ext4_get_context,
1351         .set_context            = ext4_set_context,
1352         .dummy_context          = ext4_dummy_context,
1353         .empty_dir              = ext4_empty_dir,
1354         .max_namelen            = EXT4_NAME_LEN,
1355 };
1356 #endif
1357
1358 #ifdef CONFIG_QUOTA
1359 static const char * const quotatypes[] = INITQFNAMES;
1360 #define QTYPE2NAME(t) (quotatypes[t])
1361
1362 static int ext4_write_dquot(struct dquot *dquot);
1363 static int ext4_acquire_dquot(struct dquot *dquot);
1364 static int ext4_release_dquot(struct dquot *dquot);
1365 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1366 static int ext4_write_info(struct super_block *sb, int type);
1367 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1368                          const struct path *path);
1369 static int ext4_quota_on_mount(struct super_block *sb, int type);
1370 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1371                                size_t len, loff_t off);
1372 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1373                                 const char *data, size_t len, loff_t off);
1374 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1375                              unsigned int flags);
1376 static int ext4_enable_quotas(struct super_block *sb);
1377 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1378
1379 static struct dquot **ext4_get_dquots(struct inode *inode)
1380 {
1381         return EXT4_I(inode)->i_dquot;
1382 }
1383
1384 static const struct dquot_operations ext4_quota_operations = {
1385         .get_reserved_space     = ext4_get_reserved_space,
1386         .write_dquot            = ext4_write_dquot,
1387         .acquire_dquot          = ext4_acquire_dquot,
1388         .release_dquot          = ext4_release_dquot,
1389         .mark_dirty             = ext4_mark_dquot_dirty,
1390         .write_info             = ext4_write_info,
1391         .alloc_dquot            = dquot_alloc,
1392         .destroy_dquot          = dquot_destroy,
1393         .get_projid             = ext4_get_projid,
1394         .get_inode_usage        = ext4_get_inode_usage,
1395         .get_next_id            = ext4_get_next_id,
1396 };
1397
1398 static const struct quotactl_ops ext4_qctl_operations = {
1399         .quota_on       = ext4_quota_on,
1400         .quota_off      = ext4_quota_off,
1401         .quota_sync     = dquot_quota_sync,
1402         .get_state      = dquot_get_state,
1403         .set_info       = dquot_set_dqinfo,
1404         .get_dqblk      = dquot_get_dqblk,
1405         .set_dqblk      = dquot_set_dqblk,
1406         .get_nextdqblk  = dquot_get_next_dqblk,
1407 };
1408 #endif
1409
1410 static const struct super_operations ext4_sops = {
1411         .alloc_inode    = ext4_alloc_inode,
1412         .free_inode     = ext4_free_in_core_inode,
1413         .destroy_inode  = ext4_destroy_inode,
1414         .write_inode    = ext4_write_inode,
1415         .dirty_inode    = ext4_dirty_inode,
1416         .drop_inode     = ext4_drop_inode,
1417         .evict_inode    = ext4_evict_inode,
1418         .put_super      = ext4_put_super,
1419         .sync_fs        = ext4_sync_fs,
1420         .freeze_fs      = ext4_freeze,
1421         .unfreeze_fs    = ext4_unfreeze,
1422         .statfs         = ext4_statfs,
1423         .remount_fs     = ext4_remount,
1424         .show_options   = ext4_show_options,
1425 #ifdef CONFIG_QUOTA
1426         .quota_read     = ext4_quota_read,
1427         .quota_write    = ext4_quota_write,
1428         .get_dquots     = ext4_get_dquots,
1429 #endif
1430         .bdev_try_to_free_page = bdev_try_to_free_page,
1431 };
1432
1433 static const struct export_operations ext4_export_ops = {
1434         .fh_to_dentry = ext4_fh_to_dentry,
1435         .fh_to_parent = ext4_fh_to_parent,
1436         .get_parent = ext4_get_parent,
1437         .commit_metadata = ext4_nfs_commit_metadata,
1438 };
1439
1440 enum {
1441         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1442         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1443         Opt_nouid32, Opt_debug, Opt_removed,
1444         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1445         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1446         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1447         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1448         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1449         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1450         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1451         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1452         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1453         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1454         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1455         Opt_nowarn_on_error, Opt_mblk_io_submit,
1456         Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1457         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1458         Opt_inode_readahead_blks, Opt_journal_ioprio,
1459         Opt_dioread_nolock, Opt_dioread_lock,
1460         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1461         Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1462 };
1463
1464 static const match_table_t tokens = {
1465         {Opt_bsd_df, "bsddf"},
1466         {Opt_minix_df, "minixdf"},
1467         {Opt_grpid, "grpid"},
1468         {Opt_grpid, "bsdgroups"},
1469         {Opt_nogrpid, "nogrpid"},
1470         {Opt_nogrpid, "sysvgroups"},
1471         {Opt_resgid, "resgid=%u"},
1472         {Opt_resuid, "resuid=%u"},
1473         {Opt_sb, "sb=%u"},
1474         {Opt_err_cont, "errors=continue"},
1475         {Opt_err_panic, "errors=panic"},
1476         {Opt_err_ro, "errors=remount-ro"},
1477         {Opt_nouid32, "nouid32"},
1478         {Opt_debug, "debug"},
1479         {Opt_removed, "oldalloc"},
1480         {Opt_removed, "orlov"},
1481         {Opt_user_xattr, "user_xattr"},
1482         {Opt_nouser_xattr, "nouser_xattr"},
1483         {Opt_acl, "acl"},
1484         {Opt_noacl, "noacl"},
1485         {Opt_noload, "norecovery"},
1486         {Opt_noload, "noload"},
1487         {Opt_removed, "nobh"},
1488         {Opt_removed, "bh"},
1489         {Opt_commit, "commit=%u"},
1490         {Opt_min_batch_time, "min_batch_time=%u"},
1491         {Opt_max_batch_time, "max_batch_time=%u"},
1492         {Opt_journal_dev, "journal_dev=%u"},
1493         {Opt_journal_path, "journal_path=%s"},
1494         {Opt_journal_checksum, "journal_checksum"},
1495         {Opt_nojournal_checksum, "nojournal_checksum"},
1496         {Opt_journal_async_commit, "journal_async_commit"},
1497         {Opt_abort, "abort"},
1498         {Opt_data_journal, "data=journal"},
1499         {Opt_data_ordered, "data=ordered"},
1500         {Opt_data_writeback, "data=writeback"},
1501         {Opt_data_err_abort, "data_err=abort"},
1502         {Opt_data_err_ignore, "data_err=ignore"},
1503         {Opt_offusrjquota, "usrjquota="},
1504         {Opt_usrjquota, "usrjquota=%s"},
1505         {Opt_offgrpjquota, "grpjquota="},
1506         {Opt_grpjquota, "grpjquota=%s"},
1507         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1508         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1509         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1510         {Opt_grpquota, "grpquota"},
1511         {Opt_noquota, "noquota"},
1512         {Opt_quota, "quota"},
1513         {Opt_usrquota, "usrquota"},
1514         {Opt_prjquota, "prjquota"},
1515         {Opt_barrier, "barrier=%u"},
1516         {Opt_barrier, "barrier"},
1517         {Opt_nobarrier, "nobarrier"},
1518         {Opt_i_version, "i_version"},
1519         {Opt_dax, "dax"},
1520         {Opt_stripe, "stripe=%u"},
1521         {Opt_delalloc, "delalloc"},
1522         {Opt_warn_on_error, "warn_on_error"},
1523         {Opt_nowarn_on_error, "nowarn_on_error"},
1524         {Opt_lazytime, "lazytime"},
1525         {Opt_nolazytime, "nolazytime"},
1526         {Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1527         {Opt_nodelalloc, "nodelalloc"},
1528         {Opt_removed, "mblk_io_submit"},
1529         {Opt_removed, "nomblk_io_submit"},
1530         {Opt_block_validity, "block_validity"},
1531         {Opt_noblock_validity, "noblock_validity"},
1532         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1533         {Opt_journal_ioprio, "journal_ioprio=%u"},
1534         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1535         {Opt_auto_da_alloc, "auto_da_alloc"},
1536         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1537         {Opt_dioread_nolock, "dioread_nolock"},
1538         {Opt_dioread_lock, "dioread_lock"},
1539         {Opt_discard, "discard"},
1540         {Opt_nodiscard, "nodiscard"},
1541         {Opt_init_itable, "init_itable=%u"},
1542         {Opt_init_itable, "init_itable"},
1543         {Opt_noinit_itable, "noinit_itable"},
1544         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1545         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1546         {Opt_nombcache, "nombcache"},
1547         {Opt_nombcache, "no_mbcache"},  /* for backward compatibility */
1548         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1549         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1550         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1551         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1552         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1553         {Opt_err, NULL},
1554 };
1555
1556 static ext4_fsblk_t get_sb_block(void **data)
1557 {
1558         ext4_fsblk_t    sb_block;
1559         char            *options = (char *) *data;
1560
1561         if (!options || strncmp(options, "sb=", 3) != 0)
1562                 return 1;       /* Default location */
1563
1564         options += 3;
1565         /* TODO: use simple_strtoll with >32bit ext4 */
1566         sb_block = simple_strtoul(options, &options, 0);
1567         if (*options && *options != ',') {
1568                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1569                        (char *) *data);
1570                 return 1;
1571         }
1572         if (*options == ',')
1573                 options++;
1574         *data = (void *) options;
1575
1576         return sb_block;
1577 }
1578
1579 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1580 static const char deprecated_msg[] =
1581         "Mount option \"%s\" will be removed by %s\n"
1582         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1583
1584 #ifdef CONFIG_QUOTA
1585 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1586 {
1587         struct ext4_sb_info *sbi = EXT4_SB(sb);
1588         char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1589         int ret = -1;
1590
1591         if (sb_any_quota_loaded(sb) && !old_qname) {
1592                 ext4_msg(sb, KERN_ERR,
1593                         "Cannot change journaled "
1594                         "quota options when quota turned on");
1595                 return -1;
1596         }
1597         if (ext4_has_feature_quota(sb)) {
1598                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1599                          "ignored when QUOTA feature is enabled");
1600                 return 1;
1601         }
1602         qname = match_strdup(args);
1603         if (!qname) {
1604                 ext4_msg(sb, KERN_ERR,
1605                         "Not enough memory for storing quotafile name");
1606                 return -1;
1607         }
1608         if (old_qname) {
1609                 if (strcmp(old_qname, qname) == 0)
1610                         ret = 1;
1611                 else
1612                         ext4_msg(sb, KERN_ERR,
1613                                  "%s quota file already specified",
1614                                  QTYPE2NAME(qtype));
1615                 goto errout;
1616         }
1617         if (strchr(qname, '/')) {
1618                 ext4_msg(sb, KERN_ERR,
1619                         "quotafile must be on filesystem root");
1620                 goto errout;
1621         }
1622         rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1623         set_opt(sb, QUOTA);
1624         return 1;
1625 errout:
1626         kfree(qname);
1627         return ret;
1628 }
1629
1630 static int clear_qf_name(struct super_block *sb, int qtype)
1631 {
1632
1633         struct ext4_sb_info *sbi = EXT4_SB(sb);
1634         char *old_qname = get_qf_name(sb, sbi, qtype);
1635
1636         if (sb_any_quota_loaded(sb) && old_qname) {
1637                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1638                         " when quota turned on");
1639                 return -1;
1640         }
1641         rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1642         synchronize_rcu();
1643         kfree(old_qname);
1644         return 1;
1645 }
1646 #endif
1647
1648 #define MOPT_SET        0x0001
1649 #define MOPT_CLEAR      0x0002
1650 #define MOPT_NOSUPPORT  0x0004
1651 #define MOPT_EXPLICIT   0x0008
1652 #define MOPT_CLEAR_ERR  0x0010
1653 #define MOPT_GTE0       0x0020
1654 #ifdef CONFIG_QUOTA
1655 #define MOPT_Q          0
1656 #define MOPT_QFMT       0x0040
1657 #else
1658 #define MOPT_Q          MOPT_NOSUPPORT
1659 #define MOPT_QFMT       MOPT_NOSUPPORT
1660 #endif
1661 #define MOPT_DATAJ      0x0080
1662 #define MOPT_NO_EXT2    0x0100
1663 #define MOPT_NO_EXT3    0x0200
1664 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1665 #define MOPT_STRING     0x0400
1666
1667 static const struct mount_opts {
1668         int     token;
1669         int     mount_opt;
1670         int     flags;
1671 } ext4_mount_opts[] = {
1672         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1673         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1674         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1675         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1676         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1677         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1678         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1679          MOPT_EXT4_ONLY | MOPT_SET},
1680         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1681          MOPT_EXT4_ONLY | MOPT_CLEAR},
1682         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1683         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1684         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1685          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1686         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1687          MOPT_EXT4_ONLY | MOPT_CLEAR},
1688         {Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1689         {Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1690         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1691          MOPT_EXT4_ONLY | MOPT_CLEAR},
1692         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1693          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1694         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1695                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1696          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1697         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1698         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1699         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1700         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1701         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1702          MOPT_NO_EXT2},
1703         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1704          MOPT_NO_EXT2},
1705         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1706         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1707         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1708         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1709         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1710         {Opt_commit, 0, MOPT_GTE0},
1711         {Opt_max_batch_time, 0, MOPT_GTE0},
1712         {Opt_min_batch_time, 0, MOPT_GTE0},
1713         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1714         {Opt_init_itable, 0, MOPT_GTE0},
1715         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1716         {Opt_stripe, 0, MOPT_GTE0},
1717         {Opt_resuid, 0, MOPT_GTE0},
1718         {Opt_resgid, 0, MOPT_GTE0},
1719         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1720         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1721         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1722         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1723         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1724         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1725          MOPT_NO_EXT2 | MOPT_DATAJ},
1726         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1727         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1728 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1729         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1730         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1731 #else
1732         {Opt_acl, 0, MOPT_NOSUPPORT},
1733         {Opt_noacl, 0, MOPT_NOSUPPORT},
1734 #endif
1735         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1736         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1737         {Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1738         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1739         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1740                                                         MOPT_SET | MOPT_Q},
1741         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1742                                                         MOPT_SET | MOPT_Q},
1743         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1744                                                         MOPT_SET | MOPT_Q},
1745         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1746                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1747                                                         MOPT_CLEAR | MOPT_Q},
1748         {Opt_usrjquota, 0, MOPT_Q},
1749         {Opt_grpjquota, 0, MOPT_Q},
1750         {Opt_offusrjquota, 0, MOPT_Q},
1751         {Opt_offgrpjquota, 0, MOPT_Q},
1752         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1753         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1754         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1755         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1756         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1757         {Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1758         {Opt_err, 0, 0}
1759 };
1760
1761 #ifdef CONFIG_UNICODE
1762 static const struct ext4_sb_encodings {
1763         __u16 magic;
1764         char *name;
1765         char *version;
1766 } ext4_sb_encoding_map[] = {
1767         {EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
1768 };
1769
1770 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
1771                                  const struct ext4_sb_encodings **encoding,
1772                                  __u16 *flags)
1773 {
1774         __u16 magic = le16_to_cpu(es->s_encoding);
1775         int i;
1776
1777         for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1778                 if (magic == ext4_sb_encoding_map[i].magic)
1779                         break;
1780
1781         if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
1782                 return -EINVAL;
1783
1784         *encoding = &ext4_sb_encoding_map[i];
1785         *flags = le16_to_cpu(es->s_encoding_flags);
1786
1787         return 0;
1788 }
1789 #endif
1790
1791 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1792                             substring_t *args, unsigned long *journal_devnum,
1793                             unsigned int *journal_ioprio, int is_remount)
1794 {
1795         struct ext4_sb_info *sbi = EXT4_SB(sb);
1796         const struct mount_opts *m;
1797         kuid_t uid;
1798         kgid_t gid;
1799         int arg = 0;
1800
1801 #ifdef CONFIG_QUOTA
1802         if (token == Opt_usrjquota)
1803                 return set_qf_name(sb, USRQUOTA, &args[0]);
1804         else if (token == Opt_grpjquota)
1805                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1806         else if (token == Opt_offusrjquota)
1807                 return clear_qf_name(sb, USRQUOTA);
1808         else if (token == Opt_offgrpjquota)
1809                 return clear_qf_name(sb, GRPQUOTA);
1810 #endif
1811         switch (token) {
1812         case Opt_noacl:
1813         case Opt_nouser_xattr:
1814                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1815                 break;
1816         case Opt_sb:
1817                 return 1;       /* handled by get_sb_block() */
1818         case Opt_removed:
1819                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1820                 return 1;
1821         case Opt_abort:
1822                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1823                 return 1;
1824         case Opt_i_version:
1825                 sb->s_flags |= SB_I_VERSION;
1826                 return 1;
1827         case Opt_lazytime:
1828                 sb->s_flags |= SB_LAZYTIME;
1829                 return 1;
1830         case Opt_nolazytime:
1831                 sb->s_flags &= ~SB_LAZYTIME;
1832                 return 1;
1833         }
1834
1835         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1836                 if (token == m->token)
1837                         break;
1838
1839         if (m->token == Opt_err) {
1840                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1841                          "or missing value", opt);
1842                 return -1;
1843         }
1844
1845         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1846                 ext4_msg(sb, KERN_ERR,
1847                          "Mount option \"%s\" incompatible with ext2", opt);
1848                 return -1;
1849         }
1850         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1851                 ext4_msg(sb, KERN_ERR,
1852                          "Mount option \"%s\" incompatible with ext3", opt);
1853                 return -1;
1854         }
1855
1856         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1857                 return -1;
1858         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1859                 return -1;
1860         if (m->flags & MOPT_EXPLICIT) {
1861                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1862                         set_opt2(sb, EXPLICIT_DELALLOC);
1863                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1864                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1865                 } else
1866                         return -1;
1867         }
1868         if (m->flags & MOPT_CLEAR_ERR)
1869                 clear_opt(sb, ERRORS_MASK);
1870         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1871                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1872                          "options when quota turned on");
1873                 return -1;
1874         }
1875
1876         if (m->flags & MOPT_NOSUPPORT) {
1877                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1878         } else if (token == Opt_commit) {
1879                 if (arg == 0)
1880                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1881                 sbi->s_commit_interval = HZ * arg;
1882         } else if (token == Opt_debug_want_extra_isize) {
1883                 sbi->s_want_extra_isize = arg;
1884         } else if (token == Opt_max_batch_time) {
1885                 sbi->s_max_batch_time = arg;
1886         } else if (token == Opt_min_batch_time) {
1887                 sbi->s_min_batch_time = arg;
1888         } else if (token == Opt_inode_readahead_blks) {
1889                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1890                         ext4_msg(sb, KERN_ERR,
1891                                  "EXT4-fs: inode_readahead_blks must be "
1892                                  "0 or a power of 2 smaller than 2^31");
1893                         return -1;
1894                 }
1895                 sbi->s_inode_readahead_blks = arg;
1896         } else if (token == Opt_init_itable) {
1897                 set_opt(sb, INIT_INODE_TABLE);
1898                 if (!args->from)
1899                         arg = EXT4_DEF_LI_WAIT_MULT;
1900                 sbi->s_li_wait_mult = arg;
1901         } else if (token == Opt_max_dir_size_kb) {
1902                 sbi->s_max_dir_size_kb = arg;
1903         } else if (token == Opt_stripe) {
1904                 sbi->s_stripe = arg;
1905         } else if (token == Opt_resuid) {
1906                 uid = make_kuid(current_user_ns(), arg);
1907                 if (!uid_valid(uid)) {
1908                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1909                         return -1;
1910                 }
1911                 sbi->s_resuid = uid;
1912         } else if (token == Opt_resgid) {
1913                 gid = make_kgid(current_user_ns(), arg);
1914                 if (!gid_valid(gid)) {
1915                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1916                         return -1;
1917                 }
1918                 sbi->s_resgid = gid;
1919         } else if (token == Opt_journal_dev) {
1920                 if (is_remount) {
1921                         ext4_msg(sb, KERN_ERR,
1922                                  "Cannot specify journal on remount");
1923                         return -1;
1924                 }
1925                 *journal_devnum = arg;
1926         } else if (token == Opt_journal_path) {
1927                 char *journal_path;
1928                 struct inode *journal_inode;
1929                 struct path path;
1930                 int error;
1931
1932                 if (is_remount) {
1933                         ext4_msg(sb, KERN_ERR,
1934                                  "Cannot specify journal on remount");
1935                         return -1;
1936                 }
1937                 journal_path = match_strdup(&args[0]);
1938                 if (!journal_path) {
1939                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1940                                 "journal device string");
1941                         return -1;
1942                 }
1943
1944                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1945                 if (error) {
1946                         ext4_msg(sb, KERN_ERR, "error: could not find "
1947                                 "journal device path: error %d", error);
1948                         kfree(journal_path);
1949                         return -1;
1950                 }
1951
1952                 journal_inode = d_inode(path.dentry);
1953                 if (!S_ISBLK(journal_inode->i_mode)) {
1954                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1955                                 "is not a block device", journal_path);
1956                         path_put(&path);
1957                         kfree(journal_path);
1958                         return -1;
1959                 }
1960
1961                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1962                 path_put(&path);
1963                 kfree(journal_path);
1964         } else if (token == Opt_journal_ioprio) {
1965                 if (arg > 7) {
1966                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1967                                  " (must be 0-7)");
1968                         return -1;
1969                 }
1970                 *journal_ioprio =
1971                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1972         } else if (token == Opt_test_dummy_encryption) {
1973 #ifdef CONFIG_FS_ENCRYPTION
1974                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1975                 ext4_msg(sb, KERN_WARNING,
1976                          "Test dummy encryption mode enabled");
1977 #else
1978                 ext4_msg(sb, KERN_WARNING,
1979                          "Test dummy encryption mount option ignored");
1980 #endif
1981         } else if (m->flags & MOPT_DATAJ) {
1982                 if (is_remount) {
1983                         if (!sbi->s_journal)
1984                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1985                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1986                                 ext4_msg(sb, KERN_ERR,
1987                                          "Cannot change data mode on remount");
1988                                 return -1;
1989                         }
1990                 } else {
1991                         clear_opt(sb, DATA_FLAGS);
1992                         sbi->s_mount_opt |= m->mount_opt;
1993                 }
1994 #ifdef CONFIG_QUOTA
1995         } else if (m->flags & MOPT_QFMT) {
1996                 if (sb_any_quota_loaded(sb) &&
1997                     sbi->s_jquota_fmt != m->mount_opt) {
1998                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1999                                  "quota options when quota turned on");
2000                         return -1;
2001                 }
2002                 if (ext4_has_feature_quota(sb)) {
2003                         ext4_msg(sb, KERN_INFO,
2004                                  "Quota format mount options ignored "
2005                                  "when QUOTA feature is enabled");
2006                         return 1;
2007                 }
2008                 sbi->s_jquota_fmt = m->mount_opt;
2009 #endif
2010         } else if (token == Opt_dax) {
2011 #ifdef CONFIG_FS_DAX
2012                 ext4_msg(sb, KERN_WARNING,
2013                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2014                 sbi->s_mount_opt |= m->mount_opt;
2015 #else
2016                 ext4_msg(sb, KERN_INFO, "dax option not supported");
2017                 return -1;
2018 #endif
2019         } else if (token == Opt_data_err_abort) {
2020                 sbi->s_mount_opt |= m->mount_opt;
2021         } else if (token == Opt_data_err_ignore) {
2022                 sbi->s_mount_opt &= ~m->mount_opt;
2023         } else {
2024                 if (!args->from)
2025                         arg = 1;
2026                 if (m->flags & MOPT_CLEAR)
2027                         arg = !arg;
2028                 else if (unlikely(!(m->flags & MOPT_SET))) {
2029                         ext4_msg(sb, KERN_WARNING,
2030                                  "buggy handling of option %s", opt);
2031                         WARN_ON(1);
2032                         return -1;
2033                 }
2034                 if (arg != 0)
2035                         sbi->s_mount_opt |= m->mount_opt;
2036                 else
2037                         sbi->s_mount_opt &= ~m->mount_opt;
2038         }
2039         return 1;
2040 }
2041
2042 static int parse_options(char *options, struct super_block *sb,
2043                          unsigned long *journal_devnum,
2044                          unsigned int *journal_ioprio,
2045                          int is_remount)
2046 {
2047         struct ext4_sb_info *sbi = EXT4_SB(sb);
2048         char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2049         substring_t args[MAX_OPT_ARGS];
2050         int token;
2051
2052         if (!options)
2053                 return 1;
2054
2055         while ((p = strsep(&options, ",")) != NULL) {
2056                 if (!*p)
2057                         continue;
2058                 /*
2059                  * Initialize args struct so we know whether arg was
2060                  * found; some options take optional arguments.
2061                  */
2062                 args[0].to = args[0].from = NULL;
2063                 token = match_token(p, tokens, args);
2064                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
2065                                      journal_ioprio, is_remount) < 0)
2066                         return 0;
2067         }
2068 #ifdef CONFIG_QUOTA
2069         /*
2070          * We do the test below only for project quotas. 'usrquota' and
2071          * 'grpquota' mount options are allowed even without quota feature
2072          * to support legacy quotas in quota files.
2073          */
2074         if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2075                 ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2076                          "Cannot enable project quota enforcement.");
2077                 return 0;
2078         }
2079         usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2080         grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2081         if (usr_qf_name || grp_qf_name) {
2082                 if (test_opt(sb, USRQUOTA) && usr_qf_name)
2083                         clear_opt(sb, USRQUOTA);
2084
2085                 if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2086                         clear_opt(sb, GRPQUOTA);
2087
2088                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2089                         ext4_msg(sb, KERN_ERR, "old and new quota "
2090                                         "format mixing");
2091                         return 0;
2092                 }
2093
2094                 if (!sbi->s_jquota_fmt) {
2095                         ext4_msg(sb, KERN_ERR, "journaled quota format "
2096                                         "not specified");
2097                         return 0;
2098                 }
2099         }
2100 #endif
2101         if (test_opt(sb, DIOREAD_NOLOCK)) {
2102                 int blocksize =
2103                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2104
2105                 if (blocksize < PAGE_SIZE) {
2106                         ext4_msg(sb, KERN_ERR, "can't mount with "
2107                                  "dioread_nolock if block size != PAGE_SIZE");
2108                         return 0;
2109                 }
2110         }
2111         return 1;
2112 }
2113
2114 static inline void ext4_show_quota_options(struct seq_file *seq,
2115                                            struct super_block *sb)
2116 {
2117 #if defined(CONFIG_QUOTA)
2118         struct ext4_sb_info *sbi = EXT4_SB(sb);
2119         char *usr_qf_name, *grp_qf_name;
2120
2121         if (sbi->s_jquota_fmt) {
2122                 char *fmtname = "";
2123
2124                 switch (sbi->s_jquota_fmt) {
2125                 case QFMT_VFS_OLD:
2126                         fmtname = "vfsold";
2127                         break;
2128                 case QFMT_VFS_V0:
2129                         fmtname = "vfsv0";
2130                         break;
2131                 case QFMT_VFS_V1:
2132                         fmtname = "vfsv1";
2133                         break;
2134                 }
2135                 seq_printf(seq, ",jqfmt=%s", fmtname);
2136         }
2137
2138         rcu_read_lock();
2139         usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2140         grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2141         if (usr_qf_name)
2142                 seq_show_option(seq, "usrjquota", usr_qf_name);
2143         if (grp_qf_name)
2144                 seq_show_option(seq, "grpjquota", grp_qf_name);
2145         rcu_read_unlock();
2146 #endif
2147 }
2148
2149 static const char *token2str(int token)
2150 {
2151         const struct match_token *t;
2152
2153         for (t = tokens; t->token != Opt_err; t++)
2154                 if (t->token == token && !strchr(t->pattern, '='))
2155                         break;
2156         return t->pattern;
2157 }
2158
2159 /*
2160  * Show an option if
2161  *  - it's set to a non-default value OR
2162  *  - if the per-sb default is different from the global default
2163  */
2164 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2165                               int nodefs)
2166 {
2167         struct ext4_sb_info *sbi = EXT4_SB(sb);
2168         struct ext4_super_block *es = sbi->s_es;
2169         int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2170         const struct mount_opts *m;
2171         char sep = nodefs ? '\n' : ',';
2172
2173 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2174 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2175
2176         if (sbi->s_sb_block != 1)
2177                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2178
2179         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2180                 int want_set = m->flags & MOPT_SET;
2181                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2182                     (m->flags & MOPT_CLEAR_ERR))
2183                         continue;
2184                 if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2185                         continue; /* skip if same as the default */
2186                 if ((want_set &&
2187                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2188                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2189                         continue; /* select Opt_noFoo vs Opt_Foo */
2190                 SEQ_OPTS_PRINT("%s", token2str(m->token));
2191         }
2192
2193         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2194             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2195                 SEQ_OPTS_PRINT("resuid=%u",
2196                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
2197         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2198             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2199                 SEQ_OPTS_PRINT("resgid=%u",
2200                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
2201         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2202         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2203                 SEQ_OPTS_PUTS("errors=remount-ro");
2204         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2205                 SEQ_OPTS_PUTS("errors=continue");
2206         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2207                 SEQ_OPTS_PUTS("errors=panic");
2208         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2209                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2210         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2211                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2212         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2213                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2214         if (sb->s_flags & SB_I_VERSION)
2215                 SEQ_OPTS_PUTS("i_version");
2216         if (nodefs || sbi->s_stripe)
2217                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2218         if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2219                         (sbi->s_mount_opt ^ def_mount_opt)) {
2220                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2221                         SEQ_OPTS_PUTS("data=journal");
2222                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2223                         SEQ_OPTS_PUTS("data=ordered");
2224                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2225                         SEQ_OPTS_PUTS("data=writeback");
2226         }
2227         if (nodefs ||
2228             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2229                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2230                                sbi->s_inode_readahead_blks);
2231
2232         if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2233                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2234                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2235         if (nodefs || sbi->s_max_dir_size_kb)
2236                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2237         if (test_opt(sb, DATA_ERR_ABORT))
2238                 SEQ_OPTS_PUTS("data_err=abort");
2239         if (DUMMY_ENCRYPTION_ENABLED(sbi))
2240                 SEQ_OPTS_PUTS("test_dummy_encryption");
2241
2242         ext4_show_quota_options(seq, sb);
2243         return 0;
2244 }
2245
2246 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2247 {
2248         return _ext4_show_options(seq, root->d_sb, 0);
2249 }
2250
2251 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2252 {
2253         struct super_block *sb = seq->private;
2254         int rc;
2255
2256         seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2257         rc = _ext4_show_options(seq, sb, 1);
2258         seq_puts(seq, "\n");
2259         return rc;
2260 }
2261
2262 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2263                             int read_only)
2264 {
2265         struct ext4_sb_info *sbi = EXT4_SB(sb);
2266         int err = 0;
2267
2268         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2269                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2270                          "forcing read-only mode");
2271                 err = -EROFS;
2272         }
2273         if (read_only)
2274                 goto done;
2275         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2276                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2277                          "running e2fsck is recommended");
2278         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2279                 ext4_msg(sb, KERN_WARNING,
2280                          "warning: mounting fs with errors, "
2281                          "running e2fsck is recommended");
2282         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2283                  le16_to_cpu(es->s_mnt_count) >=
2284                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2285                 ext4_msg(sb, KERN_WARNING,
2286                          "warning: maximal mount count reached, "
2287                          "running e2fsck is recommended");
2288         else if (le32_to_cpu(es->s_checkinterval) &&
2289                  (ext4_get_tstamp(es, s_lastcheck) +
2290                   le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2291                 ext4_msg(sb, KERN_WARNING,
2292                          "warning: checktime reached, "
2293                          "running e2fsck is recommended");
2294         if (!sbi->s_journal)
2295                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2296         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2297                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2298         le16_add_cpu(&es->s_mnt_count, 1);
2299         ext4_update_tstamp(es, s_mtime);
2300         if (sbi->s_journal)
2301                 ext4_set_feature_journal_needs_recovery(sb);
2302
2303         err = ext4_commit_super(sb, 1);
2304 done:
2305         if (test_opt(sb, DEBUG))
2306                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2307                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2308                         sb->s_blocksize,
2309                         sbi->s_groups_count,
2310                         EXT4_BLOCKS_PER_GROUP(sb),
2311                         EXT4_INODES_PER_GROUP(sb),
2312                         sbi->s_mount_opt, sbi->s_mount_opt2);
2313
2314         cleancache_init_fs(sb);
2315         return err;
2316 }
2317
2318 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2319 {
2320         struct ext4_sb_info *sbi = EXT4_SB(sb);
2321         struct flex_groups *new_groups;
2322         int size;
2323
2324         if (!sbi->s_log_groups_per_flex)
2325                 return 0;
2326
2327         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2328         if (size <= sbi->s_flex_groups_allocated)
2329                 return 0;
2330
2331         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2332         new_groups = kvzalloc(size, GFP_KERNEL);
2333         if (!new_groups) {
2334                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2335                          size / (int) sizeof(struct flex_groups));
2336                 return -ENOMEM;
2337         }
2338
2339         if (sbi->s_flex_groups) {
2340                 memcpy(new_groups, sbi->s_flex_groups,
2341                        (sbi->s_flex_groups_allocated *
2342                         sizeof(struct flex_groups)));
2343                 kvfree(sbi->s_flex_groups);
2344         }
2345         sbi->s_flex_groups = new_groups;
2346         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2347         return 0;
2348 }
2349
2350 static int ext4_fill_flex_info(struct super_block *sb)
2351 {
2352         struct ext4_sb_info *sbi = EXT4_SB(sb);
2353         struct ext4_group_desc *gdp = NULL;
2354         ext4_group_t flex_group;
2355         int i, err;
2356
2357         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2358         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2359                 sbi->s_log_groups_per_flex = 0;
2360                 return 1;
2361         }
2362
2363         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2364         if (err)
2365                 goto failed;
2366
2367         for (i = 0; i < sbi->s_groups_count; i++) {
2368                 gdp = ext4_get_group_desc(sb, i, NULL);
2369
2370                 flex_group = ext4_flex_group(sbi, i);
2371                 atomic_add(ext4_free_inodes_count(sb, gdp),
2372                            &sbi->s_flex_groups[flex_group].free_inodes);
2373                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2374                              &sbi->s_flex_groups[flex_group].free_clusters);
2375                 atomic_add(ext4_used_dirs_count(sb, gdp),
2376                            &sbi->s_flex_groups[flex_group].used_dirs);
2377         }
2378
2379         return 1;
2380 failed:
2381         return 0;
2382 }
2383
2384 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2385                                    struct ext4_group_desc *gdp)
2386 {
2387         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2388         __u16 crc = 0;
2389         __le32 le_group = cpu_to_le32(block_group);
2390         struct ext4_sb_info *sbi = EXT4_SB(sb);
2391
2392         if (ext4_has_metadata_csum(sbi->s_sb)) {
2393                 /* Use new metadata_csum algorithm */
2394                 __u32 csum32;
2395                 __u16 dummy_csum = 0;
2396
2397                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2398                                      sizeof(le_group));
2399                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2400                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2401                                      sizeof(dummy_csum));
2402                 offset += sizeof(dummy_csum);
2403                 if (offset < sbi->s_desc_size)
2404                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2405                                              sbi->s_desc_size - offset);
2406
2407                 crc = csum32 & 0xFFFF;
2408                 goto out;
2409         }
2410
2411         /* old crc16 code */
2412         if (!ext4_has_feature_gdt_csum(sb))
2413                 return 0;
2414
2415         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2416         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2417         crc = crc16(crc, (__u8 *)gdp, offset);
2418         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2419         /* for checksum of struct ext4_group_desc do the rest...*/
2420         if (ext4_has_feature_64bit(sb) &&
2421             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2422                 crc = crc16(crc, (__u8 *)gdp + offset,
2423                             le16_to_cpu(sbi->s_es->s_desc_size) -
2424                                 offset);
2425
2426 out:
2427         return cpu_to_le16(crc);
2428 }
2429
2430 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2431                                 struct ext4_group_desc *gdp)
2432 {
2433         if (ext4_has_group_desc_csum(sb) &&
2434             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2435                 return 0;
2436
2437         return 1;
2438 }
2439
2440 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2441                               struct ext4_group_desc *gdp)
2442 {
2443         if (!ext4_has_group_desc_csum(sb))
2444                 return;
2445         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2446 }
2447
2448 /* Called at mount-time, super-block is locked */
2449 static int ext4_check_descriptors(struct super_block *sb,
2450                                   ext4_fsblk_t sb_block,
2451                                   ext4_group_t *first_not_zeroed)
2452 {
2453         struct ext4_sb_info *sbi = EXT4_SB(sb);
2454         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2455         ext4_fsblk_t last_block;
2456         ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2457         ext4_fsblk_t block_bitmap;
2458         ext4_fsblk_t inode_bitmap;
2459         ext4_fsblk_t inode_table;
2460         int flexbg_flag = 0;
2461         ext4_group_t i, grp = sbi->s_groups_count;
2462
2463         if (ext4_has_feature_flex_bg(sb))
2464                 flexbg_flag = 1;
2465
2466         ext4_debug("Checking group descriptors");
2467
2468         for (i = 0; i < sbi->s_groups_count; i++) {
2469                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2470
2471                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2472                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2473                 else
2474                         last_block = first_block +
2475                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2476
2477                 if ((grp == sbi->s_groups_count) &&
2478                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2479                         grp = i;
2480
2481                 block_bitmap = ext4_block_bitmap(sb, gdp);
2482                 if (block_bitmap == sb_block) {
2483                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2484                                  "Block bitmap for group %u overlaps "
2485                                  "superblock", i);
2486                         if (!sb_rdonly(sb))
2487                                 return 0;
2488                 }
2489                 if (block_bitmap >= sb_block + 1 &&
2490                     block_bitmap <= last_bg_block) {
2491                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2492                                  "Block bitmap for group %u overlaps "
2493                                  "block group descriptors", i);
2494                         if (!sb_rdonly(sb))
2495                                 return 0;
2496                 }
2497                 if (block_bitmap < first_block || block_bitmap > last_block) {
2498                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2499                                "Block bitmap for group %u not in group "
2500                                "(block %llu)!", i, block_bitmap);
2501                         return 0;
2502                 }
2503                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2504                 if (inode_bitmap == sb_block) {
2505                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2506                                  "Inode bitmap for group %u overlaps "
2507                                  "superblock", i);
2508                         if (!sb_rdonly(sb))
2509                                 return 0;
2510                 }
2511                 if (inode_bitmap >= sb_block + 1 &&
2512                     inode_bitmap <= last_bg_block) {
2513                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2514                                  "Inode bitmap for group %u overlaps "
2515                                  "block group descriptors", i);
2516                         if (!sb_rdonly(sb))
2517                                 return 0;
2518                 }
2519                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2520                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2521                                "Inode bitmap for group %u not in group "
2522                                "(block %llu)!", i, inode_bitmap);
2523                         return 0;
2524                 }
2525                 inode_table = ext4_inode_table(sb, gdp);
2526                 if (inode_table == sb_block) {
2527                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2528                                  "Inode table for group %u overlaps "
2529                                  "superblock", i);
2530                         if (!sb_rdonly(sb))
2531                                 return 0;
2532                 }
2533                 if (inode_table >= sb_block + 1 &&
2534                     inode_table <= last_bg_block) {
2535                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2536                                  "Inode table for group %u overlaps "
2537                                  "block group descriptors", i);
2538                         if (!sb_rdonly(sb))
2539                                 return 0;
2540                 }
2541                 if (inode_table < first_block ||
2542                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2543                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2544                                "Inode table for group %u not in group "
2545                                "(block %llu)!", i, inode_table);
2546                         return 0;
2547                 }
2548                 ext4_lock_group(sb, i);
2549                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2550                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2551                                  "Checksum for group %u failed (%u!=%u)",
2552                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2553                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2554                         if (!sb_rdonly(sb)) {
2555                                 ext4_unlock_group(sb, i);
2556                                 return 0;
2557                         }
2558                 }
2559                 ext4_unlock_group(sb, i);
2560                 if (!flexbg_flag)
2561                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2562         }
2563         if (NULL != first_not_zeroed)
2564                 *first_not_zeroed = grp;
2565         return 1;
2566 }
2567
2568 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2569  * the superblock) which were deleted from all directories, but held open by
2570  * a process at the time of a crash.  We walk the list and try to delete these
2571  * inodes at recovery time (only with a read-write filesystem).
2572  *
2573  * In order to keep the orphan inode chain consistent during traversal (in
2574  * case of crash during recovery), we link each inode into the superblock
2575  * orphan list_head and handle it the same way as an inode deletion during
2576  * normal operation (which journals the operations for us).
2577  *
2578  * We only do an iget() and an iput() on each inode, which is very safe if we
2579  * accidentally point at an in-use or already deleted inode.  The worst that
2580  * can happen in this case is that we get a "bit already cleared" message from
2581  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2582  * e2fsck was run on this filesystem, and it must have already done the orphan
2583  * inode cleanup for us, so we can safely abort without any further action.
2584  */
2585 static void ext4_orphan_cleanup(struct super_block *sb,
2586                                 struct ext4_super_block *es)
2587 {
2588         unsigned int s_flags = sb->s_flags;
2589         int ret, nr_orphans = 0, nr_truncates = 0;
2590 #ifdef CONFIG_QUOTA
2591         int quota_update = 0;
2592         int i;
2593 #endif
2594         if (!es->s_last_orphan) {
2595                 jbd_debug(4, "no orphan inodes to clean up\n");
2596                 return;
2597         }
2598
2599         if (bdev_read_only(sb->s_bdev)) {
2600                 ext4_msg(sb, KERN_ERR, "write access "
2601                         "unavailable, skipping orphan cleanup");
2602                 return;
2603         }
2604
2605         /* Check if feature set would not allow a r/w mount */
2606         if (!ext4_feature_set_ok(sb, 0)) {
2607                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2608                          "unknown ROCOMPAT features");
2609                 return;
2610         }
2611
2612         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2613                 /* don't clear list on RO mount w/ errors */
2614                 if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2615                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2616                                   "clearing orphan list.\n");
2617                         es->s_last_orphan = 0;
2618                 }
2619                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2620                 return;
2621         }
2622
2623         if (s_flags & SB_RDONLY) {
2624                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2625                 sb->s_flags &= ~SB_RDONLY;
2626         }
2627 #ifdef CONFIG_QUOTA
2628         /* Needed for iput() to work correctly and not trash data */
2629         sb->s_flags |= SB_ACTIVE;
2630
2631         /*
2632          * Turn on quotas which were not enabled for read-only mounts if
2633          * filesystem has quota feature, so that they are updated correctly.
2634          */
2635         if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2636                 int ret = ext4_enable_quotas(sb);
2637
2638                 if (!ret)
2639                         quota_update = 1;
2640                 else
2641                         ext4_msg(sb, KERN_ERR,
2642                                 "Cannot turn on quotas: error %d", ret);
2643         }
2644
2645         /* Turn on journaled quotas used for old sytle */
2646         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2647                 if (EXT4_SB(sb)->s_qf_names[i]) {
2648                         int ret = ext4_quota_on_mount(sb, i);
2649
2650                         if (!ret)
2651                                 quota_update = 1;
2652                         else
2653                                 ext4_msg(sb, KERN_ERR,
2654                                         "Cannot turn on journaled "
2655                                         "quota: type %d: error %d", i, ret);
2656                 }
2657         }
2658 #endif
2659
2660         while (es->s_last_orphan) {
2661                 struct inode *inode;
2662
2663                 /*
2664                  * We may have encountered an error during cleanup; if
2665                  * so, skip the rest.
2666                  */
2667                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2668                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2669                         es->s_last_orphan = 0;
2670                         break;
2671                 }
2672
2673                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2674                 if (IS_ERR(inode)) {
2675                         es->s_last_orphan = 0;
2676                         break;
2677                 }
2678
2679                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2680                 dquot_initialize(inode);
2681                 if (inode->i_nlink) {
2682                         if (test_opt(sb, DEBUG))
2683                                 ext4_msg(sb, KERN_DEBUG,
2684                                         "%s: truncating inode %lu to %lld bytes",
2685                                         __func__, inode->i_ino, inode->i_size);
2686                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2687                                   inode->i_ino, inode->i_size);
2688                         inode_lock(inode);
2689                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2690                         ret = ext4_truncate(inode);
2691                         if (ret)
2692                                 ext4_std_error(inode->i_sb, ret);
2693                         inode_unlock(inode);
2694                         nr_truncates++;
2695                 } else {
2696                         if (test_opt(sb, DEBUG))
2697                                 ext4_msg(sb, KERN_DEBUG,
2698                                         "%s: deleting unreferenced inode %lu",
2699                                         __func__, inode->i_ino);
2700                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2701                                   inode->i_ino);
2702                         nr_orphans++;
2703                 }
2704                 iput(inode);  /* The delete magic happens here! */
2705         }
2706
2707 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2708
2709         if (nr_orphans)
2710                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2711                        PLURAL(nr_orphans));
2712         if (nr_truncates)
2713                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2714                        PLURAL(nr_truncates));
2715 #ifdef CONFIG_QUOTA
2716         /* Turn off quotas if they were enabled for orphan cleanup */
2717         if (quota_update) {
2718                 for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2719                         if (sb_dqopt(sb)->files[i])
2720                                 dquot_quota_off(sb, i);
2721                 }
2722         }
2723 #endif
2724         sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2725 }
2726
2727 /*
2728  * Maximal extent format file size.
2729  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2730  * extent format containers, within a sector_t, and within i_blocks
2731  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2732  * so that won't be a limiting factor.
2733  *
2734  * However there is other limiting factor. We do store extents in the form
2735  * of starting block and length, hence the resulting length of the extent
2736  * covering maximum file size must fit into on-disk format containers as
2737  * well. Given that length is always by 1 unit bigger than max unit (because
2738  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2739  *
2740  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2741  */
2742 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2743 {
2744         loff_t res;
2745         loff_t upper_limit = MAX_LFS_FILESIZE;
2746
2747         BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
2748
2749         if (!has_huge_files) {
2750                 upper_limit = (1LL << 32) - 1;
2751
2752                 /* total blocks in file system block size */
2753                 upper_limit >>= (blkbits - 9);
2754                 upper_limit <<= blkbits;
2755         }
2756
2757         /*
2758          * 32-bit extent-start container, ee_block. We lower the maxbytes
2759          * by one fs block, so ee_len can cover the extent of maximum file
2760          * size
2761          */
2762         res = (1LL << 32) - 1;
2763         res <<= blkbits;
2764
2765         /* Sanity check against vm- & vfs- imposed limits */
2766         if (res > upper_limit)
2767                 res = upper_limit;
2768
2769         return res;
2770 }
2771
2772 /*
2773  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2774  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2775  * We need to be 1 filesystem block less than the 2^48 sector limit.
2776  */
2777 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2778 {
2779         loff_t res = EXT4_NDIR_BLOCKS;
2780         int meta_blocks;
2781         loff_t upper_limit;
2782         /* This is calculated to be the largest file size for a dense, block
2783          * mapped file such that the file's total number of 512-byte sectors,
2784          * including data and all indirect blocks, does not exceed (2^48 - 1).
2785          *
2786          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2787          * number of 512-byte sectors of the file.
2788          */
2789
2790         if (!has_huge_files) {
2791                 /*
2792                  * !has_huge_files or implies that the inode i_block field
2793                  * represents total file blocks in 2^32 512-byte sectors ==
2794                  * size of vfs inode i_blocks * 8
2795                  */
2796                 upper_limit = (1LL << 32) - 1;
2797
2798                 /* total blocks in file system block size */
2799                 upper_limit >>= (bits - 9);
2800
2801         } else {
2802                 /*
2803                  * We use 48 bit ext4_inode i_blocks
2804                  * With EXT4_HUGE_FILE_FL set the i_blocks
2805                  * represent total number of blocks in
2806                  * file system block size
2807                  */
2808                 upper_limit = (1LL << 48) - 1;
2809
2810         }
2811
2812         /* indirect blocks */
2813         meta_blocks = 1;
2814         /* double indirect blocks */
2815         meta_blocks += 1 + (1LL << (bits-2));
2816         /* tripple indirect blocks */
2817         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2818
2819         upper_limit -= meta_blocks;
2820         upper_limit <<= bits;
2821
2822         res += 1LL << (bits-2);
2823         res += 1LL << (2*(bits-2));
2824         res += 1LL << (3*(bits-2));
2825         res <<= bits;
2826         if (res > upper_limit)
2827                 res = upper_limit;
2828
2829         if (res > MAX_LFS_FILESIZE)
2830                 res = MAX_LFS_FILESIZE;
2831
2832         return res;
2833 }
2834
2835 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2836                                    ext4_fsblk_t logical_sb_block, int nr)
2837 {
2838         struct ext4_sb_info *sbi = EXT4_SB(sb);
2839         ext4_group_t bg, first_meta_bg;
2840         int has_super = 0;
2841
2842         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2843
2844         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2845                 return logical_sb_block + nr + 1;
2846         bg = sbi->s_desc_per_block * nr;
2847         if (ext4_bg_has_super(sb, bg))
2848                 has_super = 1;
2849
2850         /*
2851          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2852          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2853          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2854          * compensate.
2855          */
2856         if (sb->s_blocksize == 1024 && nr == 0 &&
2857             le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2858                 has_super++;
2859
2860         return (has_super + ext4_group_first_block_no(sb, bg));
2861 }
2862
2863 /**
2864  * ext4_get_stripe_size: Get the stripe size.
2865  * @sbi: In memory super block info
2866  *
2867  * If we have specified it via mount option, then
2868  * use the mount option value. If the value specified at mount time is
2869  * greater than the blocks per group use the super block value.
2870  * If the super block value is greater than blocks per group return 0.
2871  * Allocator needs it be less than blocks per group.
2872  *
2873  */
2874 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2875 {
2876         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2877         unsigned long stripe_width =
2878                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2879         int ret;
2880
2881         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2882                 ret = sbi->s_stripe;
2883         else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2884                 ret = stripe_width;
2885         else if (stride && stride <= sbi->s_blocks_per_group)
2886                 ret = stride;
2887         else
2888                 ret = 0;
2889
2890         /*
2891          * If the stripe width is 1, this makes no sense and
2892          * we set it to 0 to turn off stripe handling code.
2893          */
2894         if (ret <= 1)
2895                 ret = 0;
2896
2897         return ret;
2898 }
2899
2900 /*
2901  * Check whether this filesystem can be mounted based on
2902  * the features present and the RDONLY/RDWR mount requested.
2903  * Returns 1 if this filesystem can be mounted as requested,
2904  * 0 if it cannot be.
2905  */
2906 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2907 {
2908         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2909                 ext4_msg(sb, KERN_ERR,
2910                         "Couldn't mount because of "
2911                         "unsupported optional features (%x)",
2912                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2913                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2914                 return 0;
2915         }
2916
2917 #ifndef CONFIG_UNICODE
2918         if (ext4_has_feature_casefold(sb)) {
2919                 ext4_msg(sb, KERN_ERR,
2920                          "Filesystem with casefold feature cannot be "
2921                          "mounted without CONFIG_UNICODE");
2922                 return 0;
2923         }
2924 #endif
2925
2926         if (readonly)
2927                 return 1;
2928
2929         if (ext4_has_feature_readonly(sb)) {
2930                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2931                 sb->s_flags |= SB_RDONLY;
2932                 return 1;
2933         }
2934
2935         /* Check that feature set is OK for a read-write mount */
2936         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2937                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2938                          "unsupported optional features (%x)",
2939                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2940                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2941                 return 0;
2942         }
2943         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2944                 ext4_msg(sb, KERN_ERR,
2945                          "Can't support bigalloc feature without "
2946                          "extents feature\n");
2947                 return 0;
2948         }
2949
2950 #ifndef CONFIG_QUOTA
2951         if (ext4_has_feature_quota(sb) && !readonly) {
2952                 ext4_msg(sb, KERN_ERR,
2953                          "Filesystem with quota feature cannot be mounted RDWR "
2954                          "without CONFIG_QUOTA");
2955                 return 0;
2956         }
2957         if (ext4_has_feature_project(sb) && !readonly) {
2958                 ext4_msg(sb, KERN_ERR,
2959                          "Filesystem with project quota feature cannot be mounted RDWR "
2960                          "without CONFIG_QUOTA");
2961                 return 0;
2962         }
2963 #endif  /* CONFIG_QUOTA */
2964         return 1;
2965 }
2966
2967 /*
2968  * This function is called once a day if we have errors logged
2969  * on the file system
2970  */
2971 static void print_daily_error_info(struct timer_list *t)
2972 {
2973         struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2974         struct super_block *sb = sbi->s_sb;
2975         struct ext4_super_block *es = sbi->s_es;
2976
2977         if (es->s_error_count)
2978                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2979                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2980                          le32_to_cpu(es->s_error_count));
2981         if (es->s_first_error_time) {
2982                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
2983                        sb->s_id,
2984                        ext4_get_tstamp(es, s_first_error_time),
2985                        (int) sizeof(es->s_first_error_func),
2986                        es->s_first_error_func,
2987                        le32_to_cpu(es->s_first_error_line));
2988                 if (es->s_first_error_ino)
2989                         printk(KERN_CONT ": inode %u",
2990                                le32_to_cpu(es->s_first_error_ino));
2991                 if (es->s_first_error_block)
2992                         printk(KERN_CONT ": block %llu", (unsigned long long)
2993                                le64_to_cpu(es->s_first_error_block));
2994                 printk(KERN_CONT "\n");
2995         }
2996         if (es->s_last_error_time) {
2997                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
2998                        sb->s_id,
2999                        ext4_get_tstamp(es, s_last_error_time),
3000                        (int) sizeof(es->s_last_error_func),
3001                        es->s_last_error_func,
3002                        le32_to_cpu(es->s_last_error_line));
3003                 if (es->s_last_error_ino)
3004                         printk(KERN_CONT ": inode %u",
3005                                le32_to_cpu(es->s_last_error_ino));
3006                 if (es->s_last_error_block)
3007                         printk(KERN_CONT ": block %llu", (unsigned long long)
3008                                le64_to_cpu(es->s_last_error_block));
3009                 printk(KERN_CONT "\n");
3010         }
3011         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3012 }
3013
3014 /* Find next suitable group and run ext4_init_inode_table */
3015 static int ext4_run_li_request(struct ext4_li_request *elr)
3016 {
3017         struct ext4_group_desc *gdp = NULL;
3018         ext4_group_t group, ngroups;
3019         struct super_block *sb;
3020         unsigned long timeout = 0;
3021         int ret = 0;
3022
3023         sb = elr->lr_super;
3024         ngroups = EXT4_SB(sb)->s_groups_count;
3025
3026         for (group = elr->lr_next_group; group < ngroups; group++) {
3027                 gdp = ext4_get_group_desc(sb, group, NULL);
3028                 if (!gdp) {
3029                         ret = 1;
3030                         break;
3031                 }
3032
3033                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3034                         break;
3035         }
3036
3037         if (group >= ngroups)
3038                 ret = 1;
3039
3040         if (!ret) {
3041                 timeout = jiffies;
3042                 ret = ext4_init_inode_table(sb, group,
3043                                             elr->lr_timeout ? 0 : 1);
3044                 if (elr->lr_timeout == 0) {
3045                         timeout = (jiffies - timeout) *
3046                                   elr->lr_sbi->s_li_wait_mult;
3047                         elr->lr_timeout = timeout;
3048                 }
3049                 elr->lr_next_sched = jiffies + elr->lr_timeout;
3050                 elr->lr_next_group = group + 1;
3051         }
3052         return ret;
3053 }
3054
3055 /*
3056  * Remove lr_request from the list_request and free the
3057  * request structure. Should be called with li_list_mtx held
3058  */
3059 static void ext4_remove_li_request(struct ext4_li_request *elr)
3060 {
3061         struct ext4_sb_info *sbi;
3062
3063         if (!elr)
3064                 return;
3065
3066         sbi = elr->lr_sbi;
3067
3068         list_del(&elr->lr_request);
3069         sbi->s_li_request = NULL;
3070         kfree(elr);
3071 }
3072
3073 static void ext4_unregister_li_request(struct super_block *sb)
3074 {
3075         mutex_lock(&ext4_li_mtx);
3076         if (!ext4_li_info) {
3077                 mutex_unlock(&ext4_li_mtx);
3078                 return;
3079         }
3080
3081         mutex_lock(&ext4_li_info->li_list_mtx);
3082         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3083         mutex_unlock(&ext4_li_info->li_list_mtx);
3084         mutex_unlock(&ext4_li_mtx);
3085 }
3086
3087 static struct task_struct *ext4_lazyinit_task;
3088
3089 /*
3090  * This is the function where ext4lazyinit thread lives. It walks
3091  * through the request list searching for next scheduled filesystem.
3092  * When such a fs is found, run the lazy initialization request
3093  * (ext4_rn_li_request) and keep track of the time spend in this
3094  * function. Based on that time we compute next schedule time of
3095  * the request. When walking through the list is complete, compute
3096  * next waking time and put itself into sleep.
3097  */
3098 static int ext4_lazyinit_thread(void *arg)
3099 {
3100         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3101         struct list_head *pos, *n;
3102         struct ext4_li_request *elr;
3103         unsigned long next_wakeup, cur;
3104
3105         BUG_ON(NULL == eli);
3106
3107 cont_thread:
3108         while (true) {
3109                 next_wakeup = MAX_JIFFY_OFFSET;
3110
3111                 mutex_lock(&eli->li_list_mtx);
3112                 if (list_empty(&eli->li_request_list)) {
3113                         mutex_unlock(&eli->li_list_mtx);
3114                         goto exit_thread;
3115                 }
3116                 list_for_each_safe(pos, n, &eli->li_request_list) {
3117                         int err = 0;
3118                         int progress = 0;
3119                         elr = list_entry(pos, struct ext4_li_request,
3120                                          lr_request);
3121
3122                         if (time_before(jiffies, elr->lr_next_sched)) {
3123                                 if (time_before(elr->lr_next_sched, next_wakeup))
3124                                         next_wakeup = elr->lr_next_sched;
3125                                 continue;
3126                         }
3127                         if (down_read_trylock(&elr->lr_super->s_umount)) {
3128                                 if (sb_start_write_trylock(elr->lr_super)) {
3129                                         progress = 1;
3130                                         /*
3131                                          * We hold sb->s_umount, sb can not
3132                                          * be removed from the list, it is
3133                                          * now safe to drop li_list_mtx
3134                                          */
3135                                         mutex_unlock(&eli->li_list_mtx);
3136                                         err = ext4_run_li_request(elr);
3137                                         sb_end_write(elr->lr_super);
3138                                         mutex_lock(&eli->li_list_mtx);
3139                                         n = pos->next;
3140                                 }
3141                                 up_read((&elr->lr_super->s_umount));
3142                         }
3143                         /* error, remove the lazy_init job */
3144                         if (err) {
3145                                 ext4_remove_li_request(elr);
3146                                 continue;
3147                         }
3148                         if (!progress) {
3149                                 elr->lr_next_sched = jiffies +
3150                                         (prandom_u32()
3151                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3152                         }
3153                         if (time_before(elr->lr_next_sched, next_wakeup))
3154                                 next_wakeup = elr->lr_next_sched;
3155                 }
3156                 mutex_unlock(&eli->li_list_mtx);
3157
3158                 try_to_freeze();
3159
3160                 cur = jiffies;
3161                 if ((time_after_eq(cur, next_wakeup)) ||
3162                     (MAX_JIFFY_OFFSET == next_wakeup)) {
3163                         cond_resched();
3164                         continue;
3165                 }
3166
3167                 schedule_timeout_interruptible(next_wakeup - cur);
3168
3169                 if (kthread_should_stop()) {
3170                         ext4_clear_request_list();
3171                         goto exit_thread;
3172                 }
3173         }
3174
3175 exit_thread:
3176         /*
3177          * It looks like the request list is empty, but we need
3178          * to check it under the li_list_mtx lock, to prevent any
3179          * additions into it, and of course we should lock ext4_li_mtx
3180          * to atomically free the list and ext4_li_info, because at
3181          * this point another ext4 filesystem could be registering
3182          * new one.
3183          */
3184         mutex_lock(&ext4_li_mtx);
3185         mutex_lock(&eli->li_list_mtx);
3186         if (!list_empty(&eli->li_request_list)) {
3187                 mutex_unlock(&eli->li_list_mtx);
3188                 mutex_unlock(&ext4_li_mtx);
3189                 goto cont_thread;
3190         }
3191         mutex_unlock(&eli->li_list_mtx);
3192         kfree(ext4_li_info);
3193         ext4_li_info = NULL;
3194         mutex_unlock(&ext4_li_mtx);
3195
3196         return 0;
3197 }
3198
3199 static void ext4_clear_request_list(void)
3200 {
3201         struct list_head *pos, *n;
3202         struct ext4_li_request *elr;
3203
3204         mutex_lock(&ext4_li_info->li_list_mtx);
3205         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3206                 elr = list_entry(pos, struct ext4_li_request,
3207                                  lr_request);
3208                 ext4_remove_li_request(elr);
3209         }
3210         mutex_unlock(&ext4_li_info->li_list_mtx);
3211 }
3212
3213 static int ext4_run_lazyinit_thread(void)
3214 {
3215         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3216                                          ext4_li_info, "ext4lazyinit");
3217         if (IS_ERR(ext4_lazyinit_task)) {
3218                 int err = PTR_ERR(ext4_lazyinit_task);
3219                 ext4_clear_request_list();
3220                 kfree(ext4_li_info);
3221                 ext4_li_info = NULL;
3222                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3223                                  "initialization thread\n",
3224                                  err);
3225                 return err;
3226         }
3227         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3228         return 0;
3229 }
3230
3231 /*
3232  * Check whether it make sense to run itable init. thread or not.
3233  * If there is at least one uninitialized inode table, return
3234  * corresponding group number, else the loop goes through all
3235  * groups and return total number of groups.
3236  */
3237 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3238 {
3239         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3240         struct ext4_group_desc *gdp = NULL;
3241
3242         if (!ext4_has_group_desc_csum(sb))
3243                 return ngroups;
3244
3245         for (group = 0; group < ngroups; group++) {
3246                 gdp = ext4_get_group_desc(sb, group, NULL);
3247                 if (!gdp)
3248                         continue;
3249
3250                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3251                         break;
3252         }
3253
3254         return group;
3255 }
3256
3257 static int ext4_li_info_new(void)
3258 {
3259         struct ext4_lazy_init *eli = NULL;
3260
3261         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3262         if (!eli)
3263                 return -ENOMEM;
3264
3265         INIT_LIST_HEAD(&eli->li_request_list);
3266         mutex_init(&eli->li_list_mtx);
3267
3268         eli->li_state |= EXT4_LAZYINIT_QUIT;
3269
3270         ext4_li_info = eli;
3271
3272         return 0;
3273 }
3274
3275 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3276                                             ext4_group_t start)
3277 {
3278         struct ext4_sb_info *sbi = EXT4_SB(sb);
3279         struct ext4_li_request *elr;
3280
3281         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3282         if (!elr)
3283                 return NULL;
3284
3285         elr->lr_super = sb;
3286         elr->lr_sbi = sbi;
3287         elr->lr_next_group = start;
3288
3289         /*
3290          * Randomize first schedule time of the request to
3291          * spread the inode table initialization requests
3292          * better.
3293          */
3294         elr->lr_next_sched = jiffies + (prandom_u32() %
3295                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3296         return elr;
3297 }
3298
3299 int ext4_register_li_request(struct super_block *sb,
3300                              ext4_group_t first_not_zeroed)
3301 {
3302         struct ext4_sb_info *sbi = EXT4_SB(sb);
3303         struct ext4_li_request *elr = NULL;
3304         ext4_group_t ngroups = sbi->s_groups_count;
3305         int ret = 0;
3306
3307         mutex_lock(&ext4_li_mtx);
3308         if (sbi->s_li_request != NULL) {
3309                 /*
3310                  * Reset timeout so it can be computed again, because
3311                  * s_li_wait_mult might have changed.
3312                  */
3313                 sbi->s_li_request->lr_timeout = 0;
3314                 goto out;
3315         }
3316
3317         if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3318             !test_opt(sb, INIT_INODE_TABLE))
3319                 goto out;
3320
3321         elr = ext4_li_request_new(sb, first_not_zeroed);
3322         if (!elr) {
3323                 ret = -ENOMEM;
3324                 goto out;
3325         }
3326
3327         if (NULL == ext4_li_info) {
3328                 ret = ext4_li_info_new();
3329                 if (ret)
3330                         goto out;
3331         }
3332
3333         mutex_lock(&ext4_li_info->li_list_mtx);
3334         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3335         mutex_unlock(&ext4_li_info->li_list_mtx);
3336
3337         sbi->s_li_request = elr;
3338         /*
3339          * set elr to NULL here since it has been inserted to
3340          * the request_list and the removal and free of it is
3341          * handled by ext4_clear_request_list from now on.
3342          */
3343         elr = NULL;
3344
3345         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3346                 ret = ext4_run_lazyinit_thread();
3347                 if (ret)
3348                         goto out;
3349         }
3350 out:
3351         mutex_unlock(&ext4_li_mtx);
3352         if (ret)
3353                 kfree(elr);
3354         return ret;
3355 }
3356
3357 /*
3358  * We do not need to lock anything since this is called on
3359  * module unload.
3360  */
3361 static void ext4_destroy_lazyinit_thread(void)
3362 {
3363         /*
3364          * If thread exited earlier
3365          * there's nothing to be done.
3366          */
3367         if (!ext4_li_info || !ext4_lazyinit_task)
3368                 return;
3369
3370         kthread_stop(ext4_lazyinit_task);
3371 }
3372
3373 static int set_journal_csum_feature_set(struct super_block *sb)
3374 {
3375         int ret = 1;
3376         int compat, incompat;
3377         struct ext4_sb_info *sbi = EXT4_SB(sb);
3378
3379         if (ext4_has_metadata_csum(sb)) {
3380                 /* journal checksum v3 */
3381                 compat = 0;
3382                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3383         } else {
3384                 /* journal checksum v1 */
3385                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3386                 incompat = 0;
3387         }
3388
3389         jbd2_journal_clear_features(sbi->s_journal,
3390                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3391                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3392                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3393         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3394                 ret = jbd2_journal_set_features(sbi->s_journal,
3395                                 compat, 0,
3396                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3397                                 incompat);
3398         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3399                 ret = jbd2_journal_set_features(sbi->s_journal,
3400                                 compat, 0,
3401                                 incompat);
3402                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3403                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3404         } else {
3405                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3406                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3407         }
3408
3409         return ret;
3410 }
3411
3412 /*
3413  * Note: calculating the overhead so we can be compatible with
3414  * historical BSD practice is quite difficult in the face of
3415  * clusters/bigalloc.  This is because multiple metadata blocks from
3416  * different block group can end up in the same allocation cluster.
3417  * Calculating the exact overhead in the face of clustered allocation
3418  * requires either O(all block bitmaps) in memory or O(number of block
3419  * groups**2) in time.  We will still calculate the superblock for
3420  * older file systems --- and if we come across with a bigalloc file
3421  * system with zero in s_overhead_clusters the estimate will be close to
3422  * correct especially for very large cluster sizes --- but for newer
3423  * file systems, it's better to calculate this figure once at mkfs
3424  * time, and store it in the superblock.  If the superblock value is
3425  * present (even for non-bigalloc file systems), we will use it.
3426  */
3427 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3428                           char *buf)
3429 {
3430         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3431         struct ext4_group_desc  *gdp;
3432         ext4_fsblk_t            first_block, last_block, b;
3433         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3434         int                     s, j, count = 0;
3435
3436         if (!ext4_has_feature_bigalloc(sb))
3437                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3438                         sbi->s_itb_per_group + 2);
3439
3440         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3441                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3442         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3443         for (i = 0; i < ngroups; i++) {
3444                 gdp = ext4_get_group_desc(sb, i, NULL);
3445                 b = ext4_block_bitmap(sb, gdp);
3446                 if (b >= first_block && b <= last_block) {
3447                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3448                         count++;
3449                 }
3450                 b = ext4_inode_bitmap(sb, gdp);
3451                 if (b >= first_block && b <= last_block) {
3452                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3453                         count++;
3454                 }
3455                 b = ext4_inode_table(sb, gdp);
3456                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3457                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3458                                 int c = EXT4_B2C(sbi, b - first_block);
3459                                 ext4_set_bit(c, buf);
3460                                 count++;
3461                         }
3462                 if (i != grp)
3463                         continue;
3464                 s = 0;
3465                 if (ext4_bg_has_super(sb, grp)) {
3466                         ext4_set_bit(s++, buf);
3467                         count++;
3468                 }
3469                 j = ext4_bg_num_gdb(sb, grp);
3470                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3471                         ext4_error(sb, "Invalid number of block group "
3472                                    "descriptor blocks: %d", j);
3473                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3474                 }
3475                 count += j;
3476                 for (; j > 0; j--)
3477                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3478         }
3479         if (!count)
3480                 return 0;
3481         return EXT4_CLUSTERS_PER_GROUP(sb) -
3482                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3483 }
3484
3485 /*
3486  * Compute the overhead and stash it in sbi->s_overhead
3487  */
3488 int ext4_calculate_overhead(struct super_block *sb)
3489 {
3490         struct ext4_sb_info *sbi = EXT4_SB(sb);
3491         struct ext4_super_block *es = sbi->s_es;
3492         struct inode *j_inode;
3493         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3494         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3495         ext4_fsblk_t overhead = 0;
3496         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3497
3498         if (!buf)
3499                 return -ENOMEM;
3500
3501         /*
3502          * Compute the overhead (FS structures).  This is constant
3503          * for a given filesystem unless the number of block groups
3504          * changes so we cache the previous value until it does.
3505          */
3506
3507         /*
3508          * All of the blocks before first_data_block are overhead
3509          */
3510         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3511
3512         /*
3513          * Add the overhead found in each block group
3514          */
3515         for (i = 0; i < ngroups; i++) {
3516                 int blks;
3517
3518                 blks = count_overhead(sb, i, buf);
3519                 overhead += blks;
3520                 if (blks)
3521                         memset(buf, 0, PAGE_SIZE);
3522                 cond_resched();
3523         }
3524
3525         /*
3526          * Add the internal journal blocks whether the journal has been
3527          * loaded or not
3528          */
3529         if (sbi->s_journal && !sbi->journal_bdev)
3530                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3531         else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3532                 j_inode = ext4_get_journal_inode(sb, j_inum);
3533                 if (j_inode) {
3534                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3535                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
3536                         iput(j_inode);
3537                 } else {
3538                         ext4_msg(sb, KERN_ERR, "can't get journal size");
3539                 }
3540         }
3541         sbi->s_overhead = overhead;
3542         smp_wmb();
3543         free_page((unsigned long) buf);
3544         return 0;
3545 }
3546
3547 static void ext4_clamp_want_extra_isize(struct super_block *sb)
3548 {
3549         struct ext4_sb_info *sbi = EXT4_SB(sb);
3550         struct ext4_super_block *es = sbi->s_es;
3551
3552         /* determine the minimum size of new large inodes, if present */
3553         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
3554             sbi->s_want_extra_isize == 0) {
3555                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3556                                                      EXT4_GOOD_OLD_INODE_SIZE;
3557                 if (ext4_has_feature_extra_isize(sb)) {
3558                         if (sbi->s_want_extra_isize <
3559                             le16_to_cpu(es->s_want_extra_isize))
3560                                 sbi->s_want_extra_isize =
3561                                         le16_to_cpu(es->s_want_extra_isize);
3562                         if (sbi->s_want_extra_isize <
3563                             le16_to_cpu(es->s_min_extra_isize))
3564                                 sbi->s_want_extra_isize =
3565                                         le16_to_cpu(es->s_min_extra_isize);
3566                 }
3567         }
3568         /* Check if enough inode space is available */
3569         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3570                                                         sbi->s_inode_size) {
3571                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3572                                                        EXT4_GOOD_OLD_INODE_SIZE;
3573                 ext4_msg(sb, KERN_INFO,
3574                          "required extra inode space not available");
3575         }
3576 }
3577
3578 static void ext4_set_resv_clusters(struct super_block *sb)
3579 {
3580         ext4_fsblk_t resv_clusters;
3581         struct ext4_sb_info *sbi = EXT4_SB(sb);
3582
3583         /*
3584          * There's no need to reserve anything when we aren't using extents.
3585          * The space estimates are exact, there are no unwritten extents,
3586          * hole punching doesn't need new metadata... This is needed especially
3587          * to keep ext2/3 backward compatibility.
3588          */
3589         if (!ext4_has_feature_extents(sb))
3590                 return;
3591         /*
3592          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3593          * This should cover the situations where we can not afford to run
3594          * out of space like for example punch hole, or converting
3595          * unwritten extents in delalloc path. In most cases such
3596          * allocation would require 1, or 2 blocks, higher numbers are
3597          * very rare.
3598          */
3599         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3600                          sbi->s_cluster_bits);
3601
3602         do_div(resv_clusters, 50);
3603         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3604
3605         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3606 }
3607
3608 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3609 {
3610         struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3611         char *orig_data = kstrdup(data, GFP_KERNEL);
3612         struct buffer_head *bh;
3613         struct ext4_super_block *es = NULL;
3614         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3615         ext4_fsblk_t block;
3616         ext4_fsblk_t sb_block = get_sb_block(&data);
3617         ext4_fsblk_t logical_sb_block;
3618         unsigned long offset = 0;
3619         unsigned long journal_devnum = 0;
3620         unsigned long def_mount_opts;
3621         struct inode *root;
3622         const char *descr;
3623         int ret = -ENOMEM;
3624         int blocksize, clustersize;
3625         unsigned int db_count;
3626         unsigned int i;
3627         int needs_recovery, has_huge_files, has_bigalloc;
3628         __u64 blocks_count;
3629         int err = 0;
3630         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3631         ext4_group_t first_not_zeroed;
3632
3633         if ((data && !orig_data) || !sbi)
3634                 goto out_free_base;
3635
3636         sbi->s_daxdev = dax_dev;
3637         sbi->s_blockgroup_lock =
3638                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3639         if (!sbi->s_blockgroup_lock)
3640                 goto out_free_base;
3641
3642         sb->s_fs_info = sbi;
3643         sbi->s_sb = sb;
3644         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3645         sbi->s_sb_block = sb_block;
3646         if (sb->s_bdev->bd_part)
3647                 sbi->s_sectors_written_start =
3648                         part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3649
3650         /* Cleanup superblock name */
3651         strreplace(sb->s_id, '/', '!');
3652
3653         /* -EINVAL is default */
3654         ret = -EINVAL;
3655         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3656         if (!blocksize) {
3657                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3658                 goto out_fail;
3659         }
3660
3661         /*
3662          * The ext4 superblock will not be buffer aligned for other than 1kB
3663          * block sizes.  We need to calculate the offset from buffer start.
3664          */
3665         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3666                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3667                 offset = do_div(logical_sb_block, blocksize);
3668         } else {
3669                 logical_sb_block = sb_block;
3670         }
3671
3672         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3673                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3674                 goto out_fail;
3675         }
3676         /*
3677          * Note: s_es must be initialized as soon as possible because
3678          *       some ext4 macro-instructions depend on its value
3679          */
3680         es = (struct ext4_super_block *) (bh->b_data + offset);
3681         sbi->s_es = es;
3682         sb->s_magic = le16_to_cpu(es->s_magic);
3683         if (sb->s_magic != EXT4_SUPER_MAGIC)
3684                 goto cantfind_ext4;
3685         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3686
3687         /* Warn if metadata_csum and gdt_csum are both set. */
3688         if (ext4_has_feature_metadata_csum(sb) &&
3689             ext4_has_feature_gdt_csum(sb))
3690                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3691                              "redundant flags; please run fsck.");
3692
3693         /* Check for a known checksum algorithm */
3694         if (!ext4_verify_csum_type(sb, es)) {
3695                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3696                          "unknown checksum algorithm.");
3697                 silent = 1;
3698                 goto cantfind_ext4;
3699         }
3700
3701         /* Load the checksum driver */
3702         sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3703         if (IS_ERR(sbi->s_chksum_driver)) {
3704                 ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3705                 ret = PTR_ERR(sbi->s_chksum_driver);
3706                 sbi->s_chksum_driver = NULL;
3707                 goto failed_mount;
3708         }
3709
3710         /* Check superblock checksum */
3711         if (!ext4_superblock_csum_verify(sb, es)) {
3712                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3713                          "invalid superblock checksum.  Run e2fsck?");
3714                 silent = 1;
3715                 ret = -EFSBADCRC;
3716                 goto cantfind_ext4;
3717         }
3718
3719         /* Precompute checksum seed for all metadata */
3720         if (ext4_has_feature_csum_seed(sb))
3721                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3722         else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3723                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3724                                                sizeof(es->s_uuid));
3725
3726         /* Set defaults before we parse the mount options */
3727         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3728         set_opt(sb, INIT_INODE_TABLE);
3729         if (def_mount_opts & EXT4_DEFM_DEBUG)
3730                 set_opt(sb, DEBUG);
3731         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3732                 set_opt(sb, GRPID);
3733         if (def_mount_opts & EXT4_DEFM_UID16)
3734                 set_opt(sb, NO_UID32);
3735         /* xattr user namespace & acls are now defaulted on */
3736         set_opt(sb, XATTR_USER);
3737 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3738         set_opt(sb, POSIX_ACL);
3739 #endif
3740         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3741         if (ext4_has_metadata_csum(sb))
3742                 set_opt(sb, JOURNAL_CHECKSUM);
3743
3744         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3745                 set_opt(sb, JOURNAL_DATA);
3746         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3747                 set_opt(sb, ORDERED_DATA);
3748         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3749                 set_opt(sb, WRITEBACK_DATA);
3750
3751         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3752                 set_opt(sb, ERRORS_PANIC);
3753         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3754                 set_opt(sb, ERRORS_CONT);
3755         else
3756                 set_opt(sb, ERRORS_RO);
3757         /* block_validity enabled by default; disable with noblock_validity */
3758         set_opt(sb, BLOCK_VALIDITY);
3759         if (def_mount_opts & EXT4_DEFM_DISCARD)
3760                 set_opt(sb, DISCARD);
3761
3762         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3763         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3764         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3765         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3766         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3767
3768         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3769                 set_opt(sb, BARRIER);
3770
3771         /*
3772          * enable delayed allocation by default
3773          * Use -o nodelalloc to turn it off
3774          */
3775         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3776             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3777                 set_opt(sb, DELALLOC);
3778
3779         /*
3780          * set default s_li_wait_mult for lazyinit, for the case there is
3781          * no mount option specified.
3782          */
3783         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3784
3785         if (sbi->s_es->s_mount_opts[0]) {
3786                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3787                                               sizeof(sbi->s_es->s_mount_opts),
3788                                               GFP_KERNEL);
3789                 if (!s_mount_opts)
3790                         goto failed_mount;
3791                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3792                                    &journal_ioprio, 0)) {
3793                         ext4_msg(sb, KERN_WARNING,
3794                                  "failed to parse options in superblock: %s",
3795                                  s_mount_opts);
3796                 }
3797                 kfree(s_mount_opts);
3798         }
3799         sbi->s_def_mount_opt = sbi->s_mount_opt;
3800         if (!parse_options((char *) data, sb, &journal_devnum,
3801                            &journal_ioprio, 0))
3802                 goto failed_mount;
3803
3804 #ifdef CONFIG_UNICODE
3805         if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
3806                 const struct ext4_sb_encodings *encoding_info;
3807                 struct unicode_map *encoding;
3808                 __u16 encoding_flags;
3809
3810                 if (ext4_has_feature_encrypt(sb)) {
3811                         ext4_msg(sb, KERN_ERR,
3812                                  "Can't mount with encoding and encryption");
3813                         goto failed_mount;
3814                 }
3815
3816                 if (ext4_sb_read_encoding(es, &encoding_info,
3817                                           &encoding_flags)) {
3818                         ext4_msg(sb, KERN_ERR,
3819                                  "Encoding requested by superblock is unknown");
3820                         goto failed_mount;
3821                 }
3822
3823                 encoding = utf8_load(encoding_info->version);
3824                 if (IS_ERR(encoding)) {
3825                         ext4_msg(sb, KERN_ERR,
3826                                  "can't mount with superblock charset: %s-%s "
3827                                  "not supported by the kernel. flags: 0x%x.",
3828                                  encoding_info->name, encoding_info->version,
3829                                  encoding_flags);
3830                         goto failed_mount;
3831                 }
3832                 ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
3833                          "%s-%s with flags 0x%hx", encoding_info->name,
3834                          encoding_info->version?:"\b", encoding_flags);
3835
3836                 sbi->s_encoding = encoding;
3837                 sbi->s_encoding_flags = encoding_flags;
3838         }
3839 #endif
3840
3841         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3842                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3843                             "with data=journal disables delayed "
3844                             "allocation and O_DIRECT support!\n");
3845                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3846                         ext4_msg(sb, KERN_ERR, "can't mount with "
3847                                  "both data=journal and delalloc");
3848                         goto failed_mount;
3849                 }
3850                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3851                         ext4_msg(sb, KERN_ERR, "can't mount with "
3852                                  "both data=journal and dioread_nolock");
3853                         goto failed_mount;
3854                 }
3855                 if (test_opt(sb, DAX)) {
3856                         ext4_msg(sb, KERN_ERR, "can't mount with "
3857                                  "both data=journal and dax");
3858                         goto failed_mount;
3859                 }
3860                 if (ext4_has_feature_encrypt(sb)) {
3861                         ext4_msg(sb, KERN_WARNING,
3862                                  "encrypted files will use data=ordered "
3863                                  "instead of data journaling mode");
3864                 }
3865                 if (test_opt(sb, DELALLOC))
3866                         clear_opt(sb, DELALLOC);
3867         } else {
3868                 sb->s_iflags |= SB_I_CGROUPWB;
3869         }
3870
3871         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3872                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3873
3874         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3875             (ext4_has_compat_features(sb) ||
3876              ext4_has_ro_compat_features(sb) ||
3877              ext4_has_incompat_features(sb)))
3878                 ext4_msg(sb, KERN_WARNING,
3879                        "feature flags set on rev 0 fs, "
3880                        "running e2fsck is recommended");
3881
3882         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3883                 set_opt2(sb, HURD_COMPAT);
3884                 if (ext4_has_feature_64bit(sb)) {
3885                         ext4_msg(sb, KERN_ERR,
3886                                  "The Hurd can't support 64-bit file systems");
3887                         goto failed_mount;
3888                 }
3889
3890                 /*
3891                  * ea_inode feature uses l_i_version field which is not
3892                  * available in HURD_COMPAT mode.
3893                  */
3894                 if (ext4_has_feature_ea_inode(sb)) {
3895                         ext4_msg(sb, KERN_ERR,
3896                                  "ea_inode feature is not supported for Hurd");
3897                         goto failed_mount;
3898                 }
3899         }
3900
3901         if (IS_EXT2_SB(sb)) {
3902                 if (ext2_feature_set_ok(sb))
3903                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3904                                  "using the ext4 subsystem");
3905                 else {
3906                         /*
3907                          * If we're probing be silent, if this looks like
3908                          * it's actually an ext[34] filesystem.
3909                          */
3910                         if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3911                                 goto failed_mount;
3912                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3913                                  "to feature incompatibilities");
3914                         goto failed_mount;
3915                 }
3916         }
3917
3918         if (IS_EXT3_SB(sb)) {
3919                 if (ext3_feature_set_ok(sb))
3920                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3921                                  "using the ext4 subsystem");
3922                 else {
3923                         /*
3924                          * If we're probing be silent, if this looks like
3925                          * it's actually an ext4 filesystem.
3926                          */
3927                         if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3928                                 goto failed_mount;
3929                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3930                                  "to feature incompatibilities");
3931                         goto failed_mount;
3932                 }
3933         }
3934
3935         /*
3936          * Check feature flags regardless of the revision level, since we
3937          * previously didn't change the revision level when setting the flags,
3938          * so there is a chance incompat flags are set on a rev 0 filesystem.
3939          */
3940         if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3941                 goto failed_mount;
3942
3943         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3944         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3945             blocksize > EXT4_MAX_BLOCK_SIZE) {
3946                 ext4_msg(sb, KERN_ERR,
3947                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3948                          blocksize, le32_to_cpu(es->s_log_block_size));
3949                 goto failed_mount;
3950         }
3951         if (le32_to_cpu(es->s_log_block_size) >
3952             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3953                 ext4_msg(sb, KERN_ERR,
3954                          "Invalid log block size: %u",
3955                          le32_to_cpu(es->s_log_block_size));
3956                 goto failed_mount;
3957         }
3958         if (le32_to_cpu(es->s_log_cluster_size) >
3959             (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3960                 ext4_msg(sb, KERN_ERR,
3961                          "Invalid log cluster size: %u",
3962                          le32_to_cpu(es->s_log_cluster_size));
3963                 goto failed_mount;
3964         }
3965
3966         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3967                 ext4_msg(sb, KERN_ERR,
3968                          "Number of reserved GDT blocks insanely large: %d",
3969                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3970                 goto failed_mount;
3971         }
3972
3973         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3974                 if (ext4_has_feature_inline_data(sb)) {
3975                         ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3976                                         " that may contain inline data");
3977                         goto failed_mount;
3978                 }
3979                 if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
3980                         ext4_msg(sb, KERN_ERR,
3981                                 "DAX unsupported by block device.");
3982                         goto failed_mount;
3983                 }
3984         }
3985
3986         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3987                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3988                          es->s_encryption_level);
3989                 goto failed_mount;
3990         }
3991
3992         if (sb->s_blocksize != blocksize) {
3993                 /* Validate the filesystem blocksize */
3994                 if (!sb_set_blocksize(sb, blocksize)) {
3995                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3996                                         blocksize);
3997                         goto failed_mount;
3998                 }
3999
4000                 brelse(bh);
4001                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4002                 offset = do_div(logical_sb_block, blocksize);
4003                 bh = sb_bread_unmovable(sb, logical_sb_block);
4004                 if (!bh) {
4005                         ext4_msg(sb, KERN_ERR,
4006                                "Can't read superblock on 2nd try");
4007                         goto failed_mount;
4008                 }
4009                 es = (struct ext4_super_block *)(bh->b_data + offset);
4010                 sbi->s_es = es;
4011                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4012                         ext4_msg(sb, KERN_ERR,
4013                                "Magic mismatch, very weird!");
4014                         goto failed_mount;
4015                 }
4016         }
4017
4018         has_huge_files = ext4_has_feature_huge_file(sb);
4019         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4020                                                       has_huge_files);
4021         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4022
4023         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4024                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4025                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4026         } else {
4027                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4028                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4029                 if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4030                         ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4031                                  sbi->s_first_ino);
4032                         goto failed_mount;
4033                 }
4034                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4035                     (!is_power_of_2(sbi->s_inode_size)) ||
4036                     (sbi->s_inode_size > blocksize)) {
4037                         ext4_msg(sb, KERN_ERR,
4038                                "unsupported inode size: %d",
4039                                sbi->s_inode_size);
4040                         goto failed_mount;
4041                 }
4042                 /*
4043                  * i_atime_extra is the last extra field available for [acm]times in
4044                  * struct ext4_inode. Checking for that field should suffice to ensure
4045                  * we have extra space for all three.
4046                  */
4047                 if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4048                         sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4049                         sb->s_time_gran = 1;
4050                         sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4051                 } else {
4052                         sb->s_time_gran = NSEC_PER_SEC;
4053                         sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4054                 }
4055
4056                 sb->s_time_min = EXT4_TIMESTAMP_MIN;
4057         }
4058
4059         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4060         if (ext4_has_feature_64bit(sb)) {
4061                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4062                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4063                     !is_power_of_2(sbi->s_desc_size)) {
4064                         ext4_msg(sb, KERN_ERR,
4065                                "unsupported descriptor size %lu",
4066                                sbi->s_desc_size);
4067                         goto failed_mount;
4068                 }
4069         } else
4070                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4071
4072         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4073         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4074
4075         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4076         if (sbi->s_inodes_per_block == 0)
4077                 goto cantfind_ext4;
4078         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4079             sbi->s_inodes_per_group > blocksize * 8) {
4080                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4081                          sbi->s_blocks_per_group);
4082                 goto failed_mount;
4083         }
4084         sbi->s_itb_per_group = sbi->s_inodes_per_group /
4085                                         sbi->s_inodes_per_block;
4086         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4087         sbi->s_sbh = bh;
4088         sbi->s_mount_state = le16_to_cpu(es->s_state);
4089         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4090         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4091
4092         for (i = 0; i < 4; i++)
4093                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4094         sbi->s_def_hash_version = es->s_def_hash_version;
4095         if (ext4_has_feature_dir_index(sb)) {
4096                 i = le32_to_cpu(es->s_flags);
4097                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
4098                         sbi->s_hash_unsigned = 3;
4099                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4100 #ifdef __CHAR_UNSIGNED__
4101                         if (!sb_rdonly(sb))
4102                                 es->s_flags |=
4103                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4104                         sbi->s_hash_unsigned = 3;
4105 #else
4106                         if (!sb_rdonly(sb))
4107                                 es->s_flags |=
4108                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4109 #endif
4110                 }
4111         }
4112
4113         /* Handle clustersize */
4114         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4115         has_bigalloc = ext4_has_feature_bigalloc(sb);
4116         if (has_bigalloc) {
4117                 if (clustersize < blocksize) {
4118                         ext4_msg(sb, KERN_ERR,
4119                                  "cluster size (%d) smaller than "
4120                                  "block size (%d)", clustersize, blocksize);
4121                         goto failed_mount;
4122                 }
4123                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4124                         le32_to_cpu(es->s_log_block_size);
4125                 sbi->s_clusters_per_group =
4126                         le32_to_cpu(es->s_clusters_per_group);
4127                 if (sbi->s_clusters_per_group > blocksize * 8) {
4128                         ext4_msg(sb, KERN_ERR,
4129                                  "#clusters per group too big: %lu",
4130                                  sbi->s_clusters_per_group);
4131                         goto failed_mount;
4132                 }
4133                 if (sbi->s_blocks_per_group !=
4134                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4135                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4136                                  "clusters per group (%lu) inconsistent",
4137                                  sbi->s_blocks_per_group,
4138                                  sbi->s_clusters_per_group);
4139                         goto failed_mount;
4140                 }
4141         } else {
4142                 if (clustersize != blocksize) {
4143                         ext4_msg(sb, KERN_ERR,
4144                                  "fragment/cluster size (%d) != "
4145                                  "block size (%d)", clustersize, blocksize);
4146                         goto failed_mount;
4147                 }
4148                 if (sbi->s_blocks_per_group > blocksize * 8) {
4149                         ext4_msg(sb, KERN_ERR,
4150                                  "#blocks per group too big: %lu",
4151                                  sbi->s_blocks_per_group);
4152                         goto failed_mount;
4153                 }
4154                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4155                 sbi->s_cluster_bits = 0;
4156         }
4157         sbi->s_cluster_ratio = clustersize / blocksize;
4158
4159         /* Do we have standard group size of clustersize * 8 blocks ? */
4160         if (sbi->s_blocks_per_group == clustersize << 3)
4161                 set_opt2(sb, STD_GROUP_SIZE);
4162
4163         /*
4164          * Test whether we have more sectors than will fit in sector_t,
4165          * and whether the max offset is addressable by the page cache.
4166          */
4167         err = generic_check_addressable(sb->s_blocksize_bits,
4168                                         ext4_blocks_count(es));
4169         if (err) {
4170                 ext4_msg(sb, KERN_ERR, "filesystem"
4171                          " too large to mount safely on this system");
4172                 goto failed_mount;
4173         }
4174
4175         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4176                 goto cantfind_ext4;
4177
4178         /* check blocks count against device size */
4179         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4180         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4181                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4182                        "exceeds size of device (%llu blocks)",
4183                        ext4_blocks_count(es), blocks_count);
4184                 goto failed_mount;
4185         }
4186
4187         /*
4188          * It makes no sense for the first data block to be beyond the end
4189          * of the filesystem.
4190          */
4191         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4192                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4193                          "block %u is beyond end of filesystem (%llu)",
4194                          le32_to_cpu(es->s_first_data_block),
4195                          ext4_blocks_count(es));
4196                 goto failed_mount;
4197         }
4198         if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4199             (sbi->s_cluster_ratio == 1)) {
4200                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4201                          "block is 0 with a 1k block and cluster size");
4202                 goto failed_mount;
4203         }
4204
4205         blocks_count = (ext4_blocks_count(es) -
4206                         le32_to_cpu(es->s_first_data_block) +
4207                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
4208         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4209         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4210                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4211                        "(block count %llu, first data block %u, "
4212                        "blocks per group %lu)", sbi->s_groups_count,
4213                        ext4_blocks_count(es),
4214                        le32_to_cpu(es->s_first_data_block),
4215                        EXT4_BLOCKS_PER_GROUP(sb));
4216                 goto failed_mount;
4217         }
4218         sbi->s_groups_count = blocks_count;
4219         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4220                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4221         if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4222             le32_to_cpu(es->s_inodes_count)) {
4223                 ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4224                          le32_to_cpu(es->s_inodes_count),
4225                          ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4226                 ret = -EINVAL;
4227                 goto failed_mount;
4228         }
4229         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4230                    EXT4_DESC_PER_BLOCK(sb);
4231         if (ext4_has_feature_meta_bg(sb)) {
4232                 if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4233                         ext4_msg(sb, KERN_WARNING,
4234                                  "first meta block group too large: %u "
4235                                  "(group descriptor block count %u)",
4236                                  le32_to_cpu(es->s_first_meta_bg), db_count);
4237                         goto failed_mount;
4238                 }
4239         }
4240         sbi->s_group_desc = kvmalloc_array(db_count,
4241                                            sizeof(struct buffer_head *),
4242                                            GFP_KERNEL);
4243         if (sbi->s_group_desc == NULL) {
4244                 ext4_msg(sb, KERN_ERR, "not enough memory");
4245                 ret = -ENOMEM;
4246                 goto failed_mount;
4247         }
4248
4249         bgl_lock_init(sbi->s_blockgroup_lock);
4250
4251         /* Pre-read the descriptors into the buffer cache */
4252         for (i = 0; i < db_count; i++) {
4253                 block = descriptor_loc(sb, logical_sb_block, i);
4254                 sb_breadahead(sb, block);
4255         }
4256
4257         for (i = 0; i < db_count; i++) {
4258                 block = descriptor_loc(sb, logical_sb_block, i);
4259                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4260                 if (!sbi->s_group_desc[i]) {
4261                         ext4_msg(sb, KERN_ERR,
4262                                "can't read group descriptor %d", i);
4263                         db_count = i;
4264                         goto failed_mount2;
4265                 }
4266         }
4267         sbi->s_gdb_count = db_count;
4268         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4269                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4270                 ret = -EFSCORRUPTED;
4271                 goto failed_mount2;
4272         }
4273
4274         timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4275
4276         /* Register extent status tree shrinker */
4277         if (ext4_es_register_shrinker(sbi))
4278                 goto failed_mount3;
4279
4280         sbi->s_stripe = ext4_get_stripe_size(sbi);
4281         sbi->s_extent_max_zeroout_kb = 32;
4282
4283         /*
4284          * set up enough so that it can read an inode
4285          */
4286         sb->s_op = &ext4_sops;
4287         sb->s_export_op = &ext4_export_ops;
4288         sb->s_xattr = ext4_xattr_handlers;
4289 #ifdef CONFIG_FS_ENCRYPTION
4290         sb->s_cop = &ext4_cryptops;
4291 #endif
4292 #ifdef CONFIG_FS_VERITY
4293         sb->s_vop = &ext4_verityops;
4294 #endif
4295 #ifdef CONFIG_QUOTA
4296         sb->dq_op = &ext4_quota_operations;
4297         if (ext4_has_feature_quota(sb))
4298                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
4299         else
4300                 sb->s_qcop = &ext4_qctl_operations;
4301         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4302 #endif
4303         memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4304
4305         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4306         mutex_init(&sbi->s_orphan_lock);
4307
4308         sb->s_root = NULL;
4309
4310         needs_recovery = (es->s_last_orphan != 0 ||
4311                           ext4_has_feature_journal_needs_recovery(sb));
4312
4313         if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4314                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4315                         goto failed_mount3a;
4316
4317         /*
4318          * The first inode we look at is the journal inode.  Don't try
4319          * root first: it may be modified in the journal!
4320          */
4321         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4322                 err = ext4_load_journal(sb, es, journal_devnum);
4323                 if (err)
4324                         goto failed_mount3a;
4325         } else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4326                    ext4_has_feature_journal_needs_recovery(sb)) {
4327                 ext4_msg(sb, KERN_ERR, "required journal recovery "
4328                        "suppressed and not mounted read-only");
4329                 goto failed_mount_wq;
4330         } else {
4331                 /* Nojournal mode, all journal mount options are illegal */
4332                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4333                         ext4_msg(sb, KERN_ERR, "can't mount with "
4334                                  "journal_checksum, fs mounted w/o journal");
4335                         goto failed_mount_wq;
4336                 }
4337                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4338                         ext4_msg(sb, KERN_ERR, "can't mount with "
4339                                  "journal_async_commit, fs mounted w/o journal");
4340                         goto failed_mount_wq;
4341                 }
4342                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4343                         ext4_msg(sb, KERN_ERR, "can't mount with "
4344                                  "commit=%lu, fs mounted w/o journal",
4345                                  sbi->s_commit_interval / HZ);
4346                         goto failed_mount_wq;
4347                 }
4348                 if (EXT4_MOUNT_DATA_FLAGS &
4349                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4350                         ext4_msg(sb, KERN_ERR, "can't mount with "
4351                                  "data=, fs mounted w/o journal");
4352                         goto failed_mount_wq;
4353                 }
4354                 sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4355                 clear_opt(sb, JOURNAL_CHECKSUM);
4356                 clear_opt(sb, DATA_FLAGS);
4357                 sbi->s_journal = NULL;
4358                 needs_recovery = 0;
4359                 goto no_journal;
4360         }
4361
4362         if (ext4_has_feature_64bit(sb) &&
4363             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4364                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
4365                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4366                 goto failed_mount_wq;
4367         }
4368
4369         if (!set_journal_csum_feature_set(sb)) {
4370                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4371                          "feature set");
4372                 goto failed_mount_wq;
4373         }
4374
4375         /* We have now updated the journal if required, so we can
4376          * validate the data journaling mode. */
4377         switch (test_opt(sb, DATA_FLAGS)) {
4378         case 0:
4379                 /* No mode set, assume a default based on the journal
4380                  * capabilities: ORDERED_DATA if the journal can
4381                  * cope, else JOURNAL_DATA
4382                  */
4383                 if (jbd2_journal_check_available_features
4384                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4385                         set_opt(sb, ORDERED_DATA);
4386                         sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4387                 } else {
4388                         set_opt(sb, JOURNAL_DATA);
4389                         sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4390                 }
4391                 break;
4392
4393         case EXT4_MOUNT_ORDERED_DATA:
4394         case EXT4_MOUNT_WRITEBACK_DATA:
4395                 if (!jbd2_journal_check_available_features
4396                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4397                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4398                                "requested data journaling mode");
4399                         goto failed_mount_wq;
4400                 }
4401         default:
4402                 break;
4403         }
4404
4405         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4406             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4407                 ext4_msg(sb, KERN_ERR, "can't mount with "
4408                         "journal_async_commit in data=ordered mode");
4409                 goto failed_mount_wq;
4410         }
4411
4412         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4413
4414         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4415
4416 no_journal:
4417         if (!test_opt(sb, NO_MBCACHE)) {
4418                 sbi->s_ea_block_cache = ext4_xattr_create_cache();
4419                 if (!sbi->s_ea_block_cache) {
4420                         ext4_msg(sb, KERN_ERR,
4421                                  "Failed to create ea_block_cache");
4422                         goto failed_mount_wq;
4423                 }
4424
4425                 if (ext4_has_feature_ea_inode(sb)) {
4426                         sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4427                         if (!sbi->s_ea_inode_cache) {
4428                                 ext4_msg(sb, KERN_ERR,
4429                                          "Failed to create ea_inode_cache");
4430                                 goto failed_mount_wq;
4431                         }
4432                 }
4433         }
4434
4435         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4436             (blocksize != PAGE_SIZE)) {
4437                 ext4_msg(sb, KERN_ERR,
4438                          "Unsupported blocksize for fs encryption");
4439                 goto failed_mount_wq;
4440         }
4441
4442         if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4443                 ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4444                 goto failed_mount_wq;
4445         }
4446
4447         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4448             !ext4_has_feature_encrypt(sb)) {
4449                 ext4_set_feature_encrypt(sb);
4450                 ext4_commit_super(sb, 1);
4451         }
4452
4453         /*
4454          * Get the # of file system overhead blocks from the
4455          * superblock if present.
4456          */
4457         if (es->s_overhead_clusters)
4458                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4459         else {
4460                 err = ext4_calculate_overhead(sb);
4461                 if (err)
4462                         goto failed_mount_wq;
4463         }
4464
4465         /*
4466          * The maximum number of concurrent works can be high and
4467          * concurrency isn't really necessary.  Limit it to 1.
4468          */
4469         EXT4_SB(sb)->rsv_conversion_wq =
4470                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4471         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4472                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4473                 ret = -ENOMEM;
4474                 goto failed_mount4;
4475         }
4476
4477         /*
4478          * The jbd2_journal_load will have done any necessary log recovery,
4479          * so we can safely mount the rest of the filesystem now.
4480          */
4481
4482         root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4483         if (IS_ERR(root)) {
4484                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4485                 ret = PTR_ERR(root);
4486                 root = NULL;
4487                 goto failed_mount4;
4488         }
4489         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4490                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4491                 iput(root);
4492                 goto failed_mount4;
4493         }
4494
4495 #ifdef CONFIG_UNICODE
4496         if (sbi->s_encoding)
4497                 sb->s_d_op = &ext4_dentry_ops;
4498 #endif
4499
4500         sb->s_root = d_make_root(root);
4501         if (!sb->s_root) {
4502                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4503                 ret = -ENOMEM;
4504                 goto failed_mount4;
4505         }
4506
4507         ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4508         if (ret == -EROFS) {
4509                 sb->s_flags |= SB_RDONLY;
4510                 ret = 0;
4511         } else if (ret)
4512                 goto failed_mount4a;
4513
4514         ext4_clamp_want_extra_isize(sb);
4515
4516         ext4_set_resv_clusters(sb);
4517
4518         err = ext4_setup_system_zone(sb);
4519         if (err) {
4520                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4521                          "zone (%d)", err);
4522                 goto failed_mount4a;
4523         }
4524
4525         ext4_ext_init(sb);
4526         err = ext4_mb_init(sb);
4527         if (err) {
4528                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4529                          err);
4530                 goto failed_mount5;
4531         }
4532
4533         block = ext4_count_free_clusters(sb);
4534         ext4_free_blocks_count_set(sbi->s_es, 
4535                                    EXT4_C2B(sbi, block));
4536         ext4_superblock_csum_set(sb);
4537         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4538                                   GFP_KERNEL);
4539         if (!err) {
4540                 unsigned long freei = ext4_count_free_inodes(sb);
4541                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4542                 ext4_superblock_csum_set(sb);
4543                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4544                                           GFP_KERNEL);
4545         }
4546         if (!err)
4547                 err = percpu_counter_init(&sbi->s_dirs_counter,
4548                                           ext4_count_dirs(sb), GFP_KERNEL);
4549         if (!err)
4550                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4551                                           GFP_KERNEL);
4552         if (!err)
4553                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4554
4555         if (err) {
4556                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4557                 goto failed_mount6;
4558         }
4559
4560         if (ext4_has_feature_flex_bg(sb))
4561                 if (!ext4_fill_flex_info(sb)) {
4562                         ext4_msg(sb, KERN_ERR,
4563                                "unable to initialize "
4564                                "flex_bg meta info!");
4565                         goto failed_mount6;
4566                 }
4567
4568         err = ext4_register_li_request(sb, first_not_zeroed);
4569         if (err)
4570                 goto failed_mount6;
4571
4572         err = ext4_register_sysfs(sb);
4573         if (err)
4574                 goto failed_mount7;
4575
4576 #ifdef CONFIG_QUOTA
4577         /* Enable quota usage during mount. */
4578         if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4579                 err = ext4_enable_quotas(sb);
4580                 if (err)
4581                         goto failed_mount8;
4582         }
4583 #endif  /* CONFIG_QUOTA */
4584
4585         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4586         ext4_orphan_cleanup(sb, es);
4587         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4588         if (needs_recovery) {
4589                 ext4_msg(sb, KERN_INFO, "recovery complete");
4590                 ext4_mark_recovery_complete(sb, es);
4591         }
4592         if (EXT4_SB(sb)->s_journal) {
4593                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4594                         descr = " journalled data mode";
4595                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4596                         descr = " ordered data mode";
4597                 else
4598                         descr = " writeback data mode";
4599         } else
4600                 descr = "out journal";
4601
4602         if (test_opt(sb, DISCARD)) {
4603                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4604                 if (!blk_queue_discard(q))
4605                         ext4_msg(sb, KERN_WARNING,
4606                                  "mounting with \"discard\" option, but "
4607                                  "the device does not support discard");
4608         }
4609
4610         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4611                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4612                          "Opts: %.*s%s%s", descr,
4613                          (int) sizeof(sbi->s_es->s_mount_opts),
4614                          sbi->s_es->s_mount_opts,
4615                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4616
4617         if (es->s_error_count)
4618                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4619
4620         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4621         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4622         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4623         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4624
4625         kfree(orig_data);
4626         return 0;
4627
4628 cantfind_ext4:
4629         if (!silent)
4630                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4631         goto failed_mount;
4632
4633 #ifdef CONFIG_QUOTA
4634 failed_mount8:
4635         ext4_unregister_sysfs(sb);
4636 #endif
4637 failed_mount7:
4638         ext4_unregister_li_request(sb);
4639 failed_mount6:
4640         ext4_mb_release(sb);
4641         if (sbi->s_flex_groups)
4642                 kvfree(sbi->s_flex_groups);
4643         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4644         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4645         percpu_counter_destroy(&sbi->s_dirs_counter);
4646         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4647         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
4648 failed_mount5:
4649         ext4_ext_release(sb);
4650         ext4_release_system_zone(sb);
4651 failed_mount4a:
4652         dput(sb->s_root);
4653         sb->s_root = NULL;
4654 failed_mount4:
4655         ext4_msg(sb, KERN_ERR, "mount failed");
4656         if (EXT4_SB(sb)->rsv_conversion_wq)
4657                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4658 failed_mount_wq:
4659         ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4660         sbi->s_ea_inode_cache = NULL;
4661
4662         ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4663         sbi->s_ea_block_cache = NULL;
4664
4665         if (sbi->s_journal) {
4666                 jbd2_journal_destroy(sbi->s_journal);
4667                 sbi->s_journal = NULL;
4668         }
4669 failed_mount3a:
4670         ext4_es_unregister_shrinker(sbi);
4671 failed_mount3:
4672         del_timer_sync(&sbi->s_err_report);
4673         if (sbi->s_mmp_tsk)
4674                 kthread_stop(sbi->s_mmp_tsk);
4675 failed_mount2:
4676         for (i = 0; i < db_count; i++)
4677                 brelse(sbi->s_group_desc[i]);
4678         kvfree(sbi->s_group_desc);
4679 failed_mount:
4680         if (sbi->s_chksum_driver)
4681                 crypto_free_shash(sbi->s_chksum_driver);
4682
4683 #ifdef CONFIG_UNICODE
4684         utf8_unload(sbi->s_encoding);
4685 #endif
4686
4687 #ifdef CONFIG_QUOTA
4688         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4689                 kfree(get_qf_name(sb, sbi, i));
4690 #endif
4691         ext4_blkdev_remove(sbi);
4692         brelse(bh);
4693 out_fail:
4694         sb->s_fs_info = NULL;
4695         kfree(sbi->s_blockgroup_lock);
4696 out_free_base:
4697         kfree(sbi);
4698         kfree(orig_data);
4699         fs_put_dax(dax_dev);
4700         return err ? err : ret;
4701 }
4702
4703 /*
4704  * Setup any per-fs journal parameters now.  We'll do this both on
4705  * initial mount, once the journal has been initialised but before we've
4706  * done any recovery; and again on any subsequent remount.
4707  */
4708 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4709 {
4710         struct ext4_sb_info *sbi = EXT4_SB(sb);
4711
4712         journal->j_commit_interval = sbi->s_commit_interval;
4713         journal->j_min_batch_time = sbi->s_min_batch_time;
4714         journal->j_max_batch_time = sbi->s_max_batch_time;
4715
4716         write_lock(&journal->j_state_lock);
4717         if (test_opt(sb, BARRIER))
4718                 journal->j_flags |= JBD2_BARRIER;
4719         else
4720                 journal->j_flags &= ~JBD2_BARRIER;
4721         if (test_opt(sb, DATA_ERR_ABORT))
4722                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4723         else
4724                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4725         write_unlock(&journal->j_state_lock);
4726 }
4727
4728 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4729                                              unsigned int journal_inum)
4730 {
4731         struct inode *journal_inode;
4732
4733         /*
4734          * Test for the existence of a valid inode on disk.  Bad things
4735          * happen if we iget() an unused inode, as the subsequent iput()
4736          * will try to delete it.
4737          */
4738         journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4739         if (IS_ERR(journal_inode)) {
4740                 ext4_msg(sb, KERN_ERR, "no journal found");
4741                 return NULL;
4742         }
4743         if (!journal_inode->i_nlink) {
4744                 make_bad_inode(journal_inode);
4745                 iput(journal_inode);
4746                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4747                 return NULL;
4748         }
4749
4750         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4751                   journal_inode, journal_inode->i_size);
4752         if (!S_ISREG(journal_inode->i_mode)) {
4753                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4754                 iput(journal_inode);
4755                 return NULL;
4756         }
4757         return journal_inode;
4758 }
4759
4760 static journal_t *ext4_get_journal(struct super_block *sb,
4761                                    unsigned int journal_inum)
4762 {
4763         struct inode *journal_inode;
4764         journal_t *journal;
4765
4766         BUG_ON(!ext4_has_feature_journal(sb));
4767
4768         journal_inode = ext4_get_journal_inode(sb, journal_inum);
4769         if (!journal_inode)
4770                 return NULL;
4771
4772         journal = jbd2_journal_init_inode(journal_inode);
4773         if (!journal) {
4774                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4775                 iput(journal_inode);
4776                 return NULL;
4777         }
4778         journal->j_private = sb;
4779         ext4_init_journal_params(sb, journal);
4780         return journal;
4781 }
4782
4783 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4784                                        dev_t j_dev)
4785 {
4786         struct buffer_head *bh;
4787         journal_t *journal;
4788         ext4_fsblk_t start;
4789         ext4_fsblk_t len;
4790         int hblock, blocksize;
4791         ext4_fsblk_t sb_block;
4792         unsigned long offset;
4793         struct ext4_super_block *es;
4794         struct block_device *bdev;
4795
4796         BUG_ON(!ext4_has_feature_journal(sb));
4797
4798         bdev = ext4_blkdev_get(j_dev, sb);
4799         if (bdev == NULL)
4800                 return NULL;
4801
4802         blocksize = sb->s_blocksize;
4803         hblock = bdev_logical_block_size(bdev);
4804         if (blocksize < hblock) {
4805                 ext4_msg(sb, KERN_ERR,
4806                         "blocksize too small for journal device");
4807                 goto out_bdev;
4808         }
4809
4810         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4811         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4812         set_blocksize(bdev, blocksize);
4813         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4814                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4815                        "external journal");
4816                 goto out_bdev;
4817         }
4818
4819         es = (struct ext4_super_block *) (bh->b_data + offset);
4820         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4821             !(le32_to_cpu(es->s_feature_incompat) &
4822               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4823                 ext4_msg(sb, KERN_ERR, "external journal has "
4824                                         "bad superblock");
4825                 brelse(bh);
4826                 goto out_bdev;
4827         }
4828
4829         if ((le32_to_cpu(es->s_feature_ro_compat) &
4830              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4831             es->s_checksum != ext4_superblock_csum(sb, es)) {
4832                 ext4_msg(sb, KERN_ERR, "external journal has "
4833                                        "corrupt superblock");
4834                 brelse(bh);
4835                 goto out_bdev;
4836         }
4837
4838         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4839                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4840                 brelse(bh);
4841                 goto out_bdev;
4842         }
4843
4844         len = ext4_blocks_count(es);
4845         start = sb_block + 1;
4846         brelse(bh);     /* we're done with the superblock */
4847
4848         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4849                                         start, len, blocksize);
4850         if (!journal) {
4851                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4852                 goto out_bdev;
4853         }
4854         journal->j_private = sb;
4855         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4856         wait_on_buffer(journal->j_sb_buffer);
4857         if (!buffer_uptodate(journal->j_sb_buffer)) {
4858                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4859                 goto out_journal;
4860         }
4861         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4862                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4863                                         "user (unsupported) - %d",
4864                         be32_to_cpu(journal->j_superblock->s_nr_users));
4865                 goto out_journal;
4866         }
4867         EXT4_SB(sb)->journal_bdev = bdev;
4868         ext4_init_journal_params(sb, journal);
4869         return journal;
4870
4871 out_journal:
4872         jbd2_journal_destroy(journal);
4873 out_bdev:
4874         ext4_blkdev_put(bdev);
4875         return NULL;
4876 }
4877
4878 static int ext4_load_journal(struct super_block *sb,
4879                              struct ext4_super_block *es,
4880                              unsigned long journal_devnum)
4881 {
4882         journal_t *journal;
4883         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4884         dev_t journal_dev;
4885         int err = 0;
4886         int really_read_only;
4887
4888         BUG_ON(!ext4_has_feature_journal(sb));
4889
4890         if (journal_devnum &&
4891             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4892                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4893                         "numbers have changed");
4894                 journal_dev = new_decode_dev(journal_devnum);
4895         } else
4896                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4897
4898         really_read_only = bdev_read_only(sb->s_bdev);
4899
4900         /*
4901          * Are we loading a blank journal or performing recovery after a
4902          * crash?  For recovery, we need to check in advance whether we
4903          * can get read-write access to the device.
4904          */
4905         if (ext4_has_feature_journal_needs_recovery(sb)) {
4906                 if (sb_rdonly(sb)) {
4907                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4908                                         "required on readonly filesystem");
4909                         if (really_read_only) {
4910                                 ext4_msg(sb, KERN_ERR, "write access "
4911                                         "unavailable, cannot proceed "
4912                                         "(try mounting with noload)");
4913                                 return -EROFS;
4914                         }
4915                         ext4_msg(sb, KERN_INFO, "write access will "
4916                                "be enabled during recovery");
4917                 }
4918         }
4919
4920         if (journal_inum && journal_dev) {
4921                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4922                        "and inode journals!");
4923                 return -EINVAL;
4924         }
4925
4926         if (journal_inum) {
4927                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4928                         return -EINVAL;
4929         } else {
4930                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4931                         return -EINVAL;
4932         }
4933
4934         if (!(journal->j_flags & JBD2_BARRIER))
4935                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4936
4937         if (!ext4_has_feature_journal_needs_recovery(sb))
4938                 err = jbd2_journal_wipe(journal, !really_read_only);
4939         if (!err) {
4940                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4941                 if (save)
4942                         memcpy(save, ((char *) es) +
4943                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4944                 err = jbd2_journal_load(journal);
4945                 if (save)
4946                         memcpy(((char *) es) + EXT4_S_ERR_START,
4947                                save, EXT4_S_ERR_LEN);
4948                 kfree(save);
4949         }
4950
4951         if (err) {
4952                 ext4_msg(sb, KERN_ERR, "error loading journal");
4953                 jbd2_journal_destroy(journal);
4954                 return err;
4955         }
4956
4957         EXT4_SB(sb)->s_journal = journal;
4958         ext4_clear_journal_err(sb, es);
4959
4960         if (!really_read_only && journal_devnum &&
4961             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4962                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4963
4964                 /* Make sure we flush the recovery flag to disk. */
4965                 ext4_commit_super(sb, 1);
4966         }
4967
4968         return 0;
4969 }
4970
4971 static int ext4_commit_super(struct super_block *sb, int sync)
4972 {
4973         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4974         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4975         int error = 0;
4976
4977         if (!sbh || block_device_ejected(sb))
4978                 return error;
4979
4980         /*
4981          * The superblock bh should be mapped, but it might not be if the
4982          * device was hot-removed. Not much we can do but fail the I/O.
4983          */
4984         if (!buffer_mapped(sbh))
4985                 return error;
4986
4987         /*
4988          * If the file system is mounted read-only, don't update the
4989          * superblock write time.  This avoids updating the superblock
4990          * write time when we are mounting the root file system
4991          * read/only but we need to replay the journal; at that point,
4992          * for people who are east of GMT and who make their clock
4993          * tick in localtime for Windows bug-for-bug compatibility,
4994          * the clock is set in the future, and this will cause e2fsck
4995          * to complain and force a full file system check.
4996          */
4997         if (!(sb->s_flags & SB_RDONLY))
4998                 ext4_update_tstamp(es, s_wtime);
4999         if (sb->s_bdev->bd_part)
5000                 es->s_kbytes_written =
5001                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5002                             ((part_stat_read(sb->s_bdev->bd_part,
5003                                              sectors[STAT_WRITE]) -
5004                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
5005         else
5006                 es->s_kbytes_written =
5007                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5008         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5009                 ext4_free_blocks_count_set(es,
5010                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5011                                 &EXT4_SB(sb)->s_freeclusters_counter)));
5012         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5013                 es->s_free_inodes_count =
5014                         cpu_to_le32(percpu_counter_sum_positive(
5015                                 &EXT4_SB(sb)->s_freeinodes_counter));
5016         BUFFER_TRACE(sbh, "marking dirty");
5017         ext4_superblock_csum_set(sb);
5018         if (sync)
5019                 lock_buffer(sbh);
5020         if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5021                 /*
5022                  * Oh, dear.  A previous attempt to write the
5023                  * superblock failed.  This could happen because the
5024                  * USB device was yanked out.  Or it could happen to
5025                  * be a transient write error and maybe the block will
5026                  * be remapped.  Nothing we can do but to retry the
5027                  * write and hope for the best.
5028                  */
5029                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
5030                        "superblock detected");
5031                 clear_buffer_write_io_error(sbh);
5032                 set_buffer_uptodate(sbh);
5033         }
5034         mark_buffer_dirty(sbh);
5035         if (sync) {
5036                 unlock_buffer(sbh);
5037                 error = __sync_dirty_buffer(sbh,
5038                         REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5039                 if (buffer_write_io_error(sbh)) {
5040                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
5041                                "superblock");
5042                         clear_buffer_write_io_error(sbh);
5043                         set_buffer_uptodate(sbh);
5044                 }
5045         }
5046         return error;
5047 }
5048
5049 /*
5050  * Have we just finished recovery?  If so, and if we are mounting (or
5051  * remounting) the filesystem readonly, then we will end up with a
5052  * consistent fs on disk.  Record that fact.
5053  */
5054 static void ext4_mark_recovery_complete(struct super_block *sb,
5055                                         struct ext4_super_block *es)
5056 {
5057         journal_t *journal = EXT4_SB(sb)->s_journal;
5058
5059         if (!ext4_has_feature_journal(sb)) {
5060                 BUG_ON(journal != NULL);
5061                 return;
5062         }
5063         jbd2_journal_lock_updates(journal);
5064         if (jbd2_journal_flush(journal) < 0)
5065                 goto out;
5066
5067         if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5068                 ext4_clear_feature_journal_needs_recovery(sb);
5069                 ext4_commit_super(sb, 1);
5070         }
5071
5072 out:
5073         jbd2_journal_unlock_updates(journal);
5074 }
5075
5076 /*
5077  * If we are mounting (or read-write remounting) a filesystem whose journal
5078  * has recorded an error from a previous lifetime, move that error to the
5079  * main filesystem now.
5080  */
5081 static void ext4_clear_journal_err(struct super_block *sb,
5082                                    struct ext4_super_block *es)
5083 {
5084         journal_t *journal;
5085         int j_errno;
5086         const char *errstr;
5087
5088         BUG_ON(!ext4_has_feature_journal(sb));
5089
5090         journal = EXT4_SB(sb)->s_journal;
5091
5092         /*
5093          * Now check for any error status which may have been recorded in the
5094          * journal by a prior ext4_error() or ext4_abort()
5095          */
5096
5097         j_errno = jbd2_journal_errno(journal);
5098         if (j_errno) {
5099                 char nbuf[16];
5100
5101                 errstr = ext4_decode_error(sb, j_errno, nbuf);
5102                 ext4_warning(sb, "Filesystem error recorded "
5103                              "from previous mount: %s", errstr);
5104                 ext4_warning(sb, "Marking fs in need of filesystem check.");
5105
5106                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5107                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5108                 ext4_commit_super(sb, 1);
5109
5110                 jbd2_journal_clear_err(journal);
5111                 jbd2_journal_update_sb_errno(journal);
5112         }
5113 }
5114
5115 /*
5116  * Force the running and committing transactions to commit,
5117  * and wait on the commit.
5118  */
5119 int ext4_force_commit(struct super_block *sb)
5120 {
5121         journal_t *journal;
5122
5123         if (sb_rdonly(sb))
5124                 return 0;
5125
5126         journal = EXT4_SB(sb)->s_journal;
5127         return ext4_journal_force_commit(journal);
5128 }
5129
5130 static int ext4_sync_fs(struct super_block *sb, int wait)
5131 {
5132         int ret = 0;
5133         tid_t target;
5134         bool needs_barrier = false;
5135         struct ext4_sb_info *sbi = EXT4_SB(sb);
5136
5137         if (unlikely(ext4_forced_shutdown(sbi)))
5138                 return 0;
5139
5140         trace_ext4_sync_fs(sb, wait);
5141         flush_workqueue(sbi->rsv_conversion_wq);
5142         /*
5143          * Writeback quota in non-journalled quota case - journalled quota has
5144          * no dirty dquots
5145          */
5146         dquot_writeback_dquots(sb, -1);
5147         /*
5148          * Data writeback is possible w/o journal transaction, so barrier must
5149          * being sent at the end of the function. But we can skip it if
5150          * transaction_commit will do it for us.
5151          */
5152         if (sbi->s_journal) {
5153                 target = jbd2_get_latest_transaction(sbi->s_journal);
5154                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5155                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5156                         needs_barrier = true;
5157
5158                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5159                         if (wait)
5160                                 ret = jbd2_log_wait_commit(sbi->s_journal,
5161                                                            target);
5162                 }
5163         } else if (wait && test_opt(sb, BARRIER))
5164                 needs_barrier = true;
5165         if (needs_barrier) {
5166                 int err;
5167                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5168                 if (!ret)
5169                         ret = err;
5170         }
5171
5172         return ret;
5173 }
5174
5175 /*
5176  * LVM calls this function before a (read-only) snapshot is created.  This
5177  * gives us a chance to flush the journal completely and mark the fs clean.
5178  *
5179  * Note that only this function cannot bring a filesystem to be in a clean
5180  * state independently. It relies on upper layer to stop all data & metadata
5181  * modifications.
5182  */
5183 static int ext4_freeze(struct super_block *sb)
5184 {
5185         int error = 0;
5186         journal_t *journal;
5187
5188         if (sb_rdonly(sb))
5189                 return 0;
5190
5191         journal = EXT4_SB(sb)->s_journal;
5192
5193         if (journal) {
5194                 /* Now we set up the journal barrier. */
5195                 jbd2_journal_lock_updates(journal);
5196
5197                 /*
5198                  * Don't clear the needs_recovery flag if we failed to
5199                  * flush the journal.
5200                  */
5201                 error = jbd2_journal_flush(journal);
5202                 if (error < 0)
5203                         goto out;
5204
5205                 /* Journal blocked and flushed, clear needs_recovery flag. */
5206                 ext4_clear_feature_journal_needs_recovery(sb);
5207         }
5208
5209         error = ext4_commit_super(sb, 1);
5210 out:
5211         if (journal)
5212                 /* we rely on upper layer to stop further updates */
5213                 jbd2_journal_unlock_updates(journal);
5214         return error;
5215 }
5216
5217 /*
5218  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5219  * flag here, even though the filesystem is not technically dirty yet.
5220  */
5221 static int ext4_unfreeze(struct super_block *sb)
5222 {
5223         if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5224                 return 0;
5225
5226         if (EXT4_SB(sb)->s_journal) {
5227                 /* Reset the needs_recovery flag before the fs is unlocked. */
5228                 ext4_set_feature_journal_needs_recovery(sb);
5229         }
5230
5231         ext4_commit_super(sb, 1);
5232         return 0;
5233 }
5234
5235 /*
5236  * Structure to save mount options for ext4_remount's benefit
5237  */
5238 struct ext4_mount_options {
5239         unsigned long s_mount_opt;
5240         unsigned long s_mount_opt2;
5241         kuid_t s_resuid;
5242         kgid_t s_resgid;
5243         unsigned long s_commit_interval;
5244         u32 s_min_batch_time, s_max_batch_time;
5245 #ifdef CONFIG_QUOTA
5246         int s_jquota_fmt;
5247         char *s_qf_names[EXT4_MAXQUOTAS];
5248 #endif
5249 };
5250
5251 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5252 {
5253         struct ext4_super_block *es;
5254         struct ext4_sb_info *sbi = EXT4_SB(sb);
5255         unsigned long old_sb_flags;
5256         struct ext4_mount_options old_opts;
5257         int enable_quota = 0;
5258         ext4_group_t g;
5259         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5260         int err = 0;
5261 #ifdef CONFIG_QUOTA
5262         int i, j;
5263         char *to_free[EXT4_MAXQUOTAS];
5264 #endif
5265         char *orig_data = kstrdup(data, GFP_KERNEL);
5266
5267         if (data && !orig_data)
5268                 return -ENOMEM;
5269
5270         /* Store the original options */
5271         old_sb_flags = sb->s_flags;
5272         old_opts.s_mount_opt = sbi->s_mount_opt;
5273         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5274         old_opts.s_resuid = sbi->s_resuid;
5275         old_opts.s_resgid = sbi->s_resgid;
5276         old_opts.s_commit_interval = sbi->s_commit_interval;
5277         old_opts.s_min_batch_time = sbi->s_min_batch_time;
5278         old_opts.s_max_batch_time = sbi->s_max_batch_time;
5279 #ifdef CONFIG_QUOTA
5280         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5281         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5282                 if (sbi->s_qf_names[i]) {
5283                         char *qf_name = get_qf_name(sb, sbi, i);
5284
5285                         old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5286                         if (!old_opts.s_qf_names[i]) {
5287                                 for (j = 0; j < i; j++)
5288                                         kfree(old_opts.s_qf_names[j]);
5289                                 kfree(orig_data);
5290                                 return -ENOMEM;
5291                         }
5292                 } else
5293                         old_opts.s_qf_names[i] = NULL;
5294 #endif
5295         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5296                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5297
5298         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5299                 err = -EINVAL;
5300                 goto restore_opts;
5301         }
5302
5303         ext4_clamp_want_extra_isize(sb);
5304
5305         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5306             test_opt(sb, JOURNAL_CHECKSUM)) {
5307                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5308                          "during remount not supported; ignoring");
5309                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5310         }
5311
5312         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5313                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5314                         ext4_msg(sb, KERN_ERR, "can't mount with "
5315                                  "both data=journal and delalloc");
5316                         err = -EINVAL;
5317                         goto restore_opts;
5318                 }
5319                 if (test_opt(sb, DIOREAD_NOLOCK)) {
5320                         ext4_msg(sb, KERN_ERR, "can't mount with "
5321                                  "both data=journal and dioread_nolock");
5322                         err = -EINVAL;
5323                         goto restore_opts;
5324                 }
5325                 if (test_opt(sb, DAX)) {
5326                         ext4_msg(sb, KERN_ERR, "can't mount with "
5327                                  "both data=journal and dax");
5328                         err = -EINVAL;
5329                         goto restore_opts;
5330                 }
5331         } else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5332                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5333                         ext4_msg(sb, KERN_ERR, "can't mount with "
5334                                 "journal_async_commit in data=ordered mode");
5335                         err = -EINVAL;
5336                         goto restore_opts;
5337                 }
5338         }
5339
5340         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5341                 ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5342                 err = -EINVAL;
5343                 goto restore_opts;
5344         }
5345
5346         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5347                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5348                         "dax flag with busy inodes while remounting");
5349                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5350         }
5351
5352         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5353                 ext4_abort(sb, "Abort forced by user");
5354
5355         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5356                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5357
5358         es = sbi->s_es;
5359
5360         if (sbi->s_journal) {
5361                 ext4_init_journal_params(sb, sbi->s_journal);
5362                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5363         }
5364
5365         if (*flags & SB_LAZYTIME)
5366                 sb->s_flags |= SB_LAZYTIME;
5367
5368         if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5369                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5370                         err = -EROFS;
5371                         goto restore_opts;
5372                 }
5373
5374                 if (*flags & SB_RDONLY) {
5375                         err = sync_filesystem(sb);
5376                         if (err < 0)
5377                                 goto restore_opts;
5378                         err = dquot_suspend(sb, -1);
5379                         if (err < 0)
5380                                 goto restore_opts;
5381
5382                         /*
5383                          * First of all, the unconditional stuff we have to do
5384                          * to disable replay of the journal when we next remount
5385                          */
5386                         sb->s_flags |= SB_RDONLY;
5387
5388                         /*
5389                          * OK, test if we are remounting a valid rw partition
5390                          * readonly, and if so set the rdonly flag and then
5391                          * mark the partition as valid again.
5392                          */
5393                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5394                             (sbi->s_mount_state & EXT4_VALID_FS))
5395                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
5396
5397                         if (sbi->s_journal)
5398                                 ext4_mark_recovery_complete(sb, es);
5399                         if (sbi->s_mmp_tsk)
5400                                 kthread_stop(sbi->s_mmp_tsk);
5401                 } else {
5402                         /* Make sure we can mount this feature set readwrite */
5403                         if (ext4_has_feature_readonly(sb) ||
5404                             !ext4_feature_set_ok(sb, 0)) {
5405                                 err = -EROFS;
5406                                 goto restore_opts;
5407                         }
5408                         /*
5409                          * Make sure the group descriptor checksums
5410                          * are sane.  If they aren't, refuse to remount r/w.
5411                          */
5412                         for (g = 0; g < sbi->s_groups_count; g++) {
5413                                 struct ext4_group_desc *gdp =
5414                                         ext4_get_group_desc(sb, g, NULL);
5415
5416                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5417                                         ext4_msg(sb, KERN_ERR,
5418                "ext4_remount: Checksum for group %u failed (%u!=%u)",
5419                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5420                                                le16_to_cpu(gdp->bg_checksum));
5421                                         err = -EFSBADCRC;
5422                                         goto restore_opts;
5423                                 }
5424                         }
5425
5426                         /*
5427                          * If we have an unprocessed orphan list hanging
5428                          * around from a previously readonly bdev mount,
5429                          * require a full umount/remount for now.
5430                          */
5431                         if (es->s_last_orphan) {
5432                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
5433                                        "remount RDWR because of unprocessed "
5434                                        "orphan inode list.  Please "
5435                                        "umount/remount instead");
5436                                 err = -EINVAL;
5437                                 goto restore_opts;
5438                         }
5439
5440                         /*
5441                          * Mounting a RDONLY partition read-write, so reread
5442                          * and store the current valid flag.  (It may have
5443                          * been changed by e2fsck since we originally mounted
5444                          * the partition.)
5445                          */
5446                         if (sbi->s_journal)
5447                                 ext4_clear_journal_err(sb, es);
5448                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5449
5450                         err = ext4_setup_super(sb, es, 0);
5451                         if (err)
5452                                 goto restore_opts;
5453
5454                         sb->s_flags &= ~SB_RDONLY;
5455                         if (ext4_has_feature_mmp(sb))
5456                                 if (ext4_multi_mount_protect(sb,
5457                                                 le64_to_cpu(es->s_mmp_block))) {
5458                                         err = -EROFS;
5459                                         goto restore_opts;
5460                                 }
5461                         enable_quota = 1;
5462                 }
5463         }
5464
5465         /*
5466          * Reinitialize lazy itable initialization thread based on
5467          * current settings
5468          */
5469         if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5470                 ext4_unregister_li_request(sb);
5471         else {
5472                 ext4_group_t first_not_zeroed;
5473                 first_not_zeroed = ext4_has_uninit_itable(sb);
5474                 ext4_register_li_request(sb, first_not_zeroed);
5475         }
5476
5477         ext4_setup_system_zone(sb);
5478         if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5479                 err = ext4_commit_super(sb, 1);
5480                 if (err)
5481                         goto restore_opts;
5482         }
5483
5484 #ifdef CONFIG_QUOTA
5485         /* Release old quota file names */
5486         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5487                 kfree(old_opts.s_qf_names[i]);
5488         if (enable_quota) {
5489                 if (sb_any_quota_suspended(sb))
5490                         dquot_resume(sb, -1);
5491                 else if (ext4_has_feature_quota(sb)) {
5492                         err = ext4_enable_quotas(sb);
5493                         if (err)
5494                                 goto restore_opts;
5495                 }
5496         }
5497 #endif
5498
5499         *flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5500         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5501         kfree(orig_data);
5502         return 0;
5503
5504 restore_opts:
5505         sb->s_flags = old_sb_flags;
5506         sbi->s_mount_opt = old_opts.s_mount_opt;
5507         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5508         sbi->s_resuid = old_opts.s_resuid;
5509         sbi->s_resgid = old_opts.s_resgid;
5510         sbi->s_commit_interval = old_opts.s_commit_interval;
5511         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5512         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5513 #ifdef CONFIG_QUOTA
5514         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5515         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5516                 to_free[i] = get_qf_name(sb, sbi, i);
5517                 rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5518         }
5519         synchronize_rcu();
5520         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5521                 kfree(to_free[i]);
5522 #endif
5523         kfree(orig_data);
5524         return err;
5525 }
5526
5527 #ifdef CONFIG_QUOTA
5528 static int ext4_statfs_project(struct super_block *sb,
5529                                kprojid_t projid, struct kstatfs *buf)
5530 {
5531         struct kqid qid;
5532         struct dquot *dquot;
5533         u64 limit;
5534         u64 curblock;
5535
5536         qid = make_kqid_projid(projid);
5537         dquot = dqget(sb, qid);
5538         if (IS_ERR(dquot))
5539                 return PTR_ERR(dquot);
5540         spin_lock(&dquot->dq_dqb_lock);
5541
5542         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5543                  dquot->dq_dqb.dqb_bsoftlimit :
5544                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5545         if (limit && buf->f_blocks > limit) {
5546                 curblock = (dquot->dq_dqb.dqb_curspace +
5547                             dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5548                 buf->f_blocks = limit;
5549                 buf->f_bfree = buf->f_bavail =
5550                         (buf->f_blocks > curblock) ?
5551                          (buf->f_blocks - curblock) : 0;
5552         }
5553
5554         limit = dquot->dq_dqb.dqb_isoftlimit ?
5555                 dquot->dq_dqb.dqb_isoftlimit :
5556                 dquot->dq_dqb.dqb_ihardlimit;
5557         if (limit && buf->f_files > limit) {
5558                 buf->f_files = limit;
5559                 buf->f_ffree =
5560                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5561                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5562         }
5563
5564         spin_unlock(&dquot->dq_dqb_lock);
5565         dqput(dquot);
5566         return 0;
5567 }
5568 #endif
5569
5570 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5571 {
5572         struct super_block *sb = dentry->d_sb;
5573         struct ext4_sb_info *sbi = EXT4_SB(sb);
5574         struct ext4_super_block *es = sbi->s_es;
5575         ext4_fsblk_t overhead = 0, resv_blocks;
5576         u64 fsid;
5577         s64 bfree;
5578         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5579
5580         if (!test_opt(sb, MINIX_DF))
5581                 overhead = sbi->s_overhead;
5582
5583         buf->f_type = EXT4_SUPER_MAGIC;
5584         buf->f_bsize = sb->s_blocksize;
5585         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5586         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5587                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5588         /* prevent underflow in case that few free space is available */
5589         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5590         buf->f_bavail = buf->f_bfree -
5591                         (ext4_r_blocks_count(es) + resv_blocks);
5592         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5593                 buf->f_bavail = 0;
5594         buf->f_files = le32_to_cpu(es->s_inodes_count);
5595         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5596         buf->f_namelen = EXT4_NAME_LEN;
5597         fsid = le64_to_cpup((void *)es->s_uuid) ^
5598                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5599         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5600         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5601
5602 #ifdef CONFIG_QUOTA
5603         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5604             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5605                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5606 #endif
5607         return 0;
5608 }
5609
5610
5611 #ifdef CONFIG_QUOTA
5612
5613 /*
5614  * Helper functions so that transaction is started before we acquire dqio_sem
5615  * to keep correct lock ordering of transaction > dqio_sem
5616  */
5617 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5618 {
5619         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5620 }
5621
5622 static int ext4_write_dquot(struct dquot *dquot)
5623 {
5624         int ret, err;
5625         handle_t *handle;
5626         struct inode *inode;
5627
5628         inode = dquot_to_inode(dquot);
5629         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5630                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5631         if (IS_ERR(handle))
5632                 return PTR_ERR(handle);
5633         ret = dquot_commit(dquot);
5634         err = ext4_journal_stop(handle);
5635         if (!ret)
5636                 ret = err;
5637         return ret;
5638 }
5639
5640 static int ext4_acquire_dquot(struct dquot *dquot)
5641 {
5642         int ret, err;
5643         handle_t *handle;
5644
5645         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5646                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5647         if (IS_ERR(handle))
5648                 return PTR_ERR(handle);
5649         ret = dquot_acquire(dquot);
5650         err = ext4_journal_stop(handle);
5651         if (!ret)
5652                 ret = err;
5653         return ret;
5654 }
5655
5656 static int ext4_release_dquot(struct dquot *dquot)
5657 {
5658         int ret, err;
5659         handle_t *handle;
5660
5661         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5662                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5663         if (IS_ERR(handle)) {
5664                 /* Release dquot anyway to avoid endless cycle in dqput() */
5665                 dquot_release(dquot);
5666                 return PTR_ERR(handle);
5667         }
5668         ret = dquot_release(dquot);
5669         err = ext4_journal_stop(handle);
5670         if (!ret)
5671                 ret = err;
5672         return ret;
5673 }
5674
5675 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5676 {
5677         struct super_block *sb = dquot->dq_sb;
5678         struct ext4_sb_info *sbi = EXT4_SB(sb);
5679
5680         /* Are we journaling quotas? */
5681         if (ext4_has_feature_quota(sb) ||
5682             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5683                 dquot_mark_dquot_dirty(dquot);
5684                 return ext4_write_dquot(dquot);
5685         } else {
5686                 return dquot_mark_dquot_dirty(dquot);
5687         }
5688 }
5689
5690 static int ext4_write_info(struct super_block *sb, int type)
5691 {
5692         int ret, err;
5693         handle_t *handle;
5694
5695         /* Data block + inode block */
5696         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5697         if (IS_ERR(handle))
5698                 return PTR_ERR(handle);
5699         ret = dquot_commit_info(sb, type);
5700         err = ext4_journal_stop(handle);
5701         if (!ret)
5702                 ret = err;
5703         return ret;
5704 }
5705
5706 /*
5707  * Turn on quotas during mount time - we need to find
5708  * the quota file and such...
5709  */
5710 static int ext4_quota_on_mount(struct super_block *sb, int type)
5711 {
5712         return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5713                                         EXT4_SB(sb)->s_jquota_fmt, type);
5714 }
5715
5716 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5717 {
5718         struct ext4_inode_info *ei = EXT4_I(inode);
5719
5720         /* The first argument of lockdep_set_subclass has to be
5721          * *exactly* the same as the argument to init_rwsem() --- in
5722          * this case, in init_once() --- or lockdep gets unhappy
5723          * because the name of the lock is set using the
5724          * stringification of the argument to init_rwsem().
5725          */
5726         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5727         lockdep_set_subclass(&ei->i_data_sem, subclass);
5728 }
5729
5730 /*
5731  * Standard function to be called on quota_on
5732  */
5733 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5734                          const struct path *path)
5735 {
5736         int err;
5737
5738         if (!test_opt(sb, QUOTA))
5739                 return -EINVAL;
5740
5741         /* Quotafile not on the same filesystem? */
5742         if (path->dentry->d_sb != sb)
5743                 return -EXDEV;
5744         /* Journaling quota? */
5745         if (EXT4_SB(sb)->s_qf_names[type]) {
5746                 /* Quotafile not in fs root? */
5747                 if (path->dentry->d_parent != sb->s_root)
5748                         ext4_msg(sb, KERN_WARNING,
5749                                 "Quota file not on filesystem root. "
5750                                 "Journaled quota will not work");
5751                 sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5752         } else {
5753                 /*
5754                  * Clear the flag just in case mount options changed since
5755                  * last time.
5756                  */
5757                 sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5758         }
5759
5760         /*
5761          * When we journal data on quota file, we have to flush journal to see
5762          * all updates to the file when we bypass pagecache...
5763          */
5764         if (EXT4_SB(sb)->s_journal &&
5765             ext4_should_journal_data(d_inode(path->dentry))) {
5766                 /*
5767                  * We don't need to lock updates but journal_flush() could
5768                  * otherwise be livelocked...
5769                  */
5770                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5771                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5772                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5773                 if (err)
5774                         return err;
5775         }
5776
5777         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5778         err = dquot_quota_on(sb, type, format_id, path);
5779         if (err) {
5780                 lockdep_set_quota_inode(path->dentry->d_inode,
5781                                              I_DATA_SEM_NORMAL);
5782         } else {
5783                 struct inode *inode = d_inode(path->dentry);
5784                 handle_t *handle;
5785
5786                 /*
5787                  * Set inode flags to prevent userspace from messing with quota
5788                  * files. If this fails, we return success anyway since quotas
5789                  * are already enabled and this is not a hard failure.
5790                  */
5791                 inode_lock(inode);
5792                 handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5793                 if (IS_ERR(handle))
5794                         goto unlock_inode;
5795                 EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5796                 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5797                                 S_NOATIME | S_IMMUTABLE);
5798                 ext4_mark_inode_dirty(handle, inode);
5799                 ext4_journal_stop(handle);
5800         unlock_inode:
5801                 inode_unlock(inode);
5802         }
5803         return err;
5804 }
5805
5806 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5807                              unsigned int flags)
5808 {
5809         int err;
5810         struct inode *qf_inode;
5811         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5812                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5813                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5814                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5815         };
5816
5817         BUG_ON(!ext4_has_feature_quota(sb));
5818
5819         if (!qf_inums[type])
5820                 return -EPERM;
5821
5822         qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5823         if (IS_ERR(qf_inode)) {
5824                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5825                 return PTR_ERR(qf_inode);
5826         }
5827
5828         /* Don't account quota for quota files to avoid recursion */
5829         qf_inode->i_flags |= S_NOQUOTA;
5830         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5831         err = dquot_enable(qf_inode, type, format_id, flags);
5832         if (err)
5833                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5834         iput(qf_inode);
5835
5836         return err;
5837 }
5838
5839 /* Enable usage tracking for all quota types. */
5840 static int ext4_enable_quotas(struct super_block *sb)
5841 {
5842         int type, err = 0;
5843         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5844                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5845                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5846                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5847         };
5848         bool quota_mopt[EXT4_MAXQUOTAS] = {
5849                 test_opt(sb, USRQUOTA),
5850                 test_opt(sb, GRPQUOTA),
5851                 test_opt(sb, PRJQUOTA),
5852         };
5853
5854         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5855         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5856                 if (qf_inums[type]) {
5857                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5858                                 DQUOT_USAGE_ENABLED |
5859                                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5860                         if (err) {
5861                                 ext4_warning(sb,
5862                                         "Failed to enable quota tracking "
5863                                         "(type=%d, err=%d). Please run "
5864                                         "e2fsck to fix.", type, err);
5865                                 for (type--; type >= 0; type--)
5866                                         dquot_quota_off(sb, type);
5867
5868                                 return err;
5869                         }
5870                 }
5871         }
5872         return 0;
5873 }
5874
5875 static int ext4_quota_off(struct super_block *sb, int type)
5876 {
5877         struct inode *inode = sb_dqopt(sb)->files[type];
5878         handle_t *handle;
5879         int err;
5880
5881         /* Force all delayed allocation blocks to be allocated.
5882          * Caller already holds s_umount sem */
5883         if (test_opt(sb, DELALLOC))
5884                 sync_filesystem(sb);
5885
5886         if (!inode || !igrab(inode))
5887                 goto out;
5888
5889         err = dquot_quota_off(sb, type);
5890         if (err || ext4_has_feature_quota(sb))
5891                 goto out_put;
5892
5893         inode_lock(inode);
5894         /*
5895          * Update modification times of quota files when userspace can
5896          * start looking at them. If we fail, we return success anyway since
5897          * this is not a hard failure and quotas are already disabled.
5898          */
5899         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5900         if (IS_ERR(handle))
5901                 goto out_unlock;
5902         EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5903         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5904         inode->i_mtime = inode->i_ctime = current_time(inode);
5905         ext4_mark_inode_dirty(handle, inode);
5906         ext4_journal_stop(handle);
5907 out_unlock:
5908         inode_unlock(inode);
5909 out_put:
5910         lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5911         iput(inode);
5912         return err;
5913 out:
5914         return dquot_quota_off(sb, type);
5915 }
5916
5917 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5918  * acquiring the locks... As quota files are never truncated and quota code
5919  * itself serializes the operations (and no one else should touch the files)
5920  * we don't have to be afraid of races */
5921 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5922                                size_t len, loff_t off)
5923 {
5924         struct inode *inode = sb_dqopt(sb)->files[type];
5925         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5926         int offset = off & (sb->s_blocksize - 1);
5927         int tocopy;
5928         size_t toread;
5929         struct buffer_head *bh;
5930         loff_t i_size = i_size_read(inode);
5931
5932         if (off > i_size)
5933                 return 0;
5934         if (off+len > i_size)
5935                 len = i_size-off;
5936         toread = len;
5937         while (toread > 0) {
5938                 tocopy = sb->s_blocksize - offset < toread ?
5939                                 sb->s_blocksize - offset : toread;
5940                 bh = ext4_bread(NULL, inode, blk, 0);
5941                 if (IS_ERR(bh))
5942                         return PTR_ERR(bh);
5943                 if (!bh)        /* A hole? */
5944                         memset(data, 0, tocopy);
5945                 else
5946                         memcpy(data, bh->b_data+offset, tocopy);
5947                 brelse(bh);
5948                 offset = 0;
5949                 toread -= tocopy;
5950                 data += tocopy;
5951                 blk++;
5952         }
5953         return len;
5954 }
5955
5956 /* Write to quotafile (we know the transaction is already started and has
5957  * enough credits) */
5958 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5959                                 const char *data, size_t len, loff_t off)
5960 {
5961         struct inode *inode = sb_dqopt(sb)->files[type];
5962         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5963         int err, offset = off & (sb->s_blocksize - 1);
5964         int retries = 0;
5965         struct buffer_head *bh;
5966         handle_t *handle = journal_current_handle();
5967
5968         if (EXT4_SB(sb)->s_journal && !handle) {
5969                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5970                         " cancelled because transaction is not started",
5971                         (unsigned long long)off, (unsigned long long)len);
5972                 return -EIO;
5973         }
5974         /*
5975          * Since we account only one data block in transaction credits,
5976          * then it is impossible to cross a block boundary.
5977          */
5978         if (sb->s_blocksize - offset < len) {
5979                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5980                         " cancelled because not block aligned",
5981                         (unsigned long long)off, (unsigned long long)len);
5982                 return -EIO;
5983         }
5984
5985         do {
5986                 bh = ext4_bread(handle, inode, blk,
5987                                 EXT4_GET_BLOCKS_CREATE |
5988                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5989         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5990                  ext4_should_retry_alloc(inode->i_sb, &retries));
5991         if (IS_ERR(bh))
5992                 return PTR_ERR(bh);
5993         if (!bh)
5994                 goto out;
5995         BUFFER_TRACE(bh, "get write access");
5996         err = ext4_journal_get_write_access(handle, bh);
5997         if (err) {
5998                 brelse(bh);
5999                 return err;
6000         }
6001         lock_buffer(bh);
6002         memcpy(bh->b_data+offset, data, len);
6003         flush_dcache_page(bh->b_page);
6004         unlock_buffer(bh);
6005         err = ext4_handle_dirty_metadata(handle, NULL, bh);
6006         brelse(bh);
6007 out:
6008         if (inode->i_size < off + len) {
6009                 i_size_write(inode, off + len);
6010                 EXT4_I(inode)->i_disksize = inode->i_size;
6011                 ext4_mark_inode_dirty(handle, inode);
6012         }
6013         return len;
6014 }
6015
6016 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
6017 {
6018         const struct quota_format_ops   *ops;
6019
6020         if (!sb_has_quota_loaded(sb, qid->type))
6021                 return -ESRCH;
6022         ops = sb_dqopt(sb)->ops[qid->type];
6023         if (!ops || !ops->get_next_id)
6024                 return -ENOSYS;
6025         return dquot_get_next_id(sb, qid);
6026 }
6027 #endif
6028
6029 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6030                        const char *dev_name, void *data)
6031 {
6032         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6033 }
6034
6035 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6036 static inline void register_as_ext2(void)
6037 {
6038         int err = register_filesystem(&ext2_fs_type);
6039         if (err)
6040                 printk(KERN_WARNING
6041                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6042 }
6043
6044 static inline void unregister_as_ext2(void)
6045 {
6046         unregister_filesystem(&ext2_fs_type);
6047 }
6048
6049 static inline int ext2_feature_set_ok(struct super_block *sb)
6050 {
6051         if (ext4_has_unknown_ext2_incompat_features(sb))
6052                 return 0;
6053         if (sb_rdonly(sb))
6054                 return 1;
6055         if (ext4_has_unknown_ext2_ro_compat_features(sb))
6056                 return 0;
6057         return 1;
6058 }
6059 #else
6060 static inline void register_as_ext2(void) { }
6061 static inline void unregister_as_ext2(void) { }
6062 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6063 #endif
6064
6065 static inline void register_as_ext3(void)
6066 {
6067         int err = register_filesystem(&ext3_fs_type);
6068         if (err)
6069                 printk(KERN_WARNING
6070                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6071 }
6072
6073 static inline void unregister_as_ext3(void)
6074 {
6075         unregister_filesystem(&ext3_fs_type);
6076 }
6077
6078 static inline int ext3_feature_set_ok(struct super_block *sb)
6079 {
6080         if (ext4_has_unknown_ext3_incompat_features(sb))
6081                 return 0;
6082         if (!ext4_has_feature_journal(sb))
6083                 return 0;
6084         if (sb_rdonly(sb))
6085                 return 1;
6086         if (ext4_has_unknown_ext3_ro_compat_features(sb))
6087                 return 0;
6088         return 1;
6089 }
6090
6091 static struct file_system_type ext4_fs_type = {
6092         .owner          = THIS_MODULE,
6093         .name           = "ext4",
6094         .mount          = ext4_mount,
6095         .kill_sb        = kill_block_super,
6096         .fs_flags       = FS_REQUIRES_DEV,
6097 };
6098 MODULE_ALIAS_FS("ext4");
6099
6100 /* Shared across all ext4 file systems */
6101 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6102
6103 static int __init ext4_init_fs(void)
6104 {
6105         int i, err;
6106
6107         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6108         ext4_li_info = NULL;
6109         mutex_init(&ext4_li_mtx);
6110
6111         /* Build-time check for flags consistency */
6112         ext4_check_flag_values();
6113
6114         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6115                 init_waitqueue_head(&ext4__ioend_wq[i]);
6116
6117         err = ext4_init_es();
6118         if (err)
6119                 return err;
6120
6121         err = ext4_init_pending();
6122         if (err)
6123                 goto out7;
6124
6125         err = ext4_init_post_read_processing();
6126         if (err)
6127                 goto out6;
6128
6129         err = ext4_init_pageio();
6130         if (err)
6131                 goto out5;
6132
6133         err = ext4_init_system_zone();
6134         if (err)
6135                 goto out4;
6136
6137         err = ext4_init_sysfs();
6138         if (err)
6139                 goto out3;
6140
6141         err = ext4_init_mballoc();
6142         if (err)
6143                 goto out2;
6144         err = init_inodecache();
6145         if (err)
6146                 goto out1;
6147         register_as_ext3();
6148         register_as_ext2();
6149         err = register_filesystem(&ext4_fs_type);
6150         if (err)
6151                 goto out;
6152
6153         return 0;
6154 out:
6155         unregister_as_ext2();
6156         unregister_as_ext3();
6157         destroy_inodecache();
6158 out1:
6159         ext4_exit_mballoc();
6160 out2:
6161         ext4_exit_sysfs();
6162 out3:
6163         ext4_exit_system_zone();
6164 out4:
6165         ext4_exit_pageio();
6166 out5:
6167         ext4_exit_post_read_processing();
6168 out6:
6169         ext4_exit_pending();
6170 out7:
6171         ext4_exit_es();
6172
6173         return err;
6174 }
6175
6176 static void __exit ext4_exit_fs(void)
6177 {
6178         ext4_destroy_lazyinit_thread();
6179         unregister_as_ext2();
6180         unregister_as_ext3();
6181         unregister_filesystem(&ext4_fs_type);
6182         destroy_inodecache();
6183         ext4_exit_mballoc();
6184         ext4_exit_sysfs();
6185         ext4_exit_system_zone();
6186         ext4_exit_pageio();
6187         ext4_exit_post_read_processing();
6188         ext4_exit_es();
6189         ext4_exit_pending();
6190 }
6191
6192 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6193 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6194 MODULE_LICENSE("GPL");
6195 MODULE_SOFTDEP("pre: crc32c");
6196 module_init(ext4_init_fs)
6197 module_exit(ext4_exit_fs)