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Linux/fs/ext4/super.c

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  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 
 46 #include <linux/kthread.h>
 47 #include <linux/freezer.h>
 48 
 49 #include "ext4.h"
 50 #include "ext4_extents.h"       /* Needed for trace points definition */
 51 #include "ext4_jbd2.h"
 52 #include "xattr.h"
 53 #include "acl.h"
 54 #include "mballoc.h"
 55 #include "fsmap.h"
 56 
 57 #define CREATE_TRACE_POINTS
 58 #include <trace/events/ext4.h>
 59 
 60 static struct ext4_lazy_init *ext4_li_info;
 61 static struct mutex ext4_li_mtx;
 62 static struct ratelimit_state ext4_mount_msg_ratelimit;
 63 
 64 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
 65                              unsigned long journal_devnum);
 66 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
 67 static int ext4_commit_super(struct super_block *sb, int sync);
 68 static void ext4_mark_recovery_complete(struct super_block *sb,
 69                                         struct ext4_super_block *es);
 70 static void ext4_clear_journal_err(struct super_block *sb,
 71                                    struct ext4_super_block *es);
 72 static int ext4_sync_fs(struct super_block *sb, int wait);
 73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
 74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
 75 static int ext4_unfreeze(struct super_block *sb);
 76 static int ext4_freeze(struct super_block *sb);
 77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
 78                        const char *dev_name, void *data);
 79 static inline int ext2_feature_set_ok(struct super_block *sb);
 80 static inline int ext3_feature_set_ok(struct super_block *sb);
 81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
 82 static void ext4_destroy_lazyinit_thread(void);
 83 static void ext4_unregister_li_request(struct super_block *sb);
 84 static void ext4_clear_request_list(void);
 85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
 86                                             unsigned int journal_inum);
 87 
 88 /*
 89  * Lock ordering
 90  *
 91  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
 92  * i_mmap_rwsem (inode->i_mmap_rwsem)!
 93  *
 94  * page fault path:
 95  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
 96  *   page lock -> i_data_sem (rw)
 97  *
 98  * buffered write path:
 99  * sb_start_write -> i_mutex -> mmap_sem
100  * sb_start_write -> i_mutex -> transaction start -> page lock ->
101  *   i_data_sem (rw)
102  *
103  * truncate:
104  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
105  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
106  *   i_data_sem (rw)
107  *
108  * direct IO:
109  * sb_start_write -> i_mutex -> mmap_sem
110  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
111  *
112  * writepages:
113  * transaction start -> page lock(s) -> i_data_sem (rw)
114  */
115 
116 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
117 static struct file_system_type ext2_fs_type = {
118         .owner          = THIS_MODULE,
119         .name           = "ext2",
120         .mount          = ext4_mount,
121         .kill_sb        = kill_block_super,
122         .fs_flags       = FS_REQUIRES_DEV,
123 };
124 MODULE_ALIAS_FS("ext2");
125 MODULE_ALIAS("ext2");
126 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
127 #else
128 #define IS_EXT2_SB(sb) (0)
129 #endif
130 
131 
132 static struct file_system_type ext3_fs_type = {
133         .owner          = THIS_MODULE,
134         .name           = "ext3",
135         .mount          = ext4_mount,
136         .kill_sb        = kill_block_super,
137         .fs_flags       = FS_REQUIRES_DEV,
138 };
139 MODULE_ALIAS_FS("ext3");
140 MODULE_ALIAS("ext3");
141 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
142 
143 /*
144  * This works like sb_bread() except it uses ERR_PTR for error
145  * returns.  Currently with sb_bread it's impossible to distinguish
146  * between ENOMEM and EIO situations (since both result in a NULL
147  * return.
148  */
149 struct buffer_head *
150 ext4_sb_bread(struct super_block *sb, sector_t block, int op_flags)
151 {
152         struct buffer_head *bh = sb_getblk(sb, block);
153 
154         if (bh == NULL)
155                 return ERR_PTR(-ENOMEM);
156         if (buffer_uptodate(bh))
157                 return bh;
158         ll_rw_block(REQ_OP_READ, REQ_META | op_flags, 1, &bh);
159         wait_on_buffer(bh);
160         if (buffer_uptodate(bh))
161                 return bh;
162         put_bh(bh);
163         return ERR_PTR(-EIO);
164 }
165 
166 static int ext4_verify_csum_type(struct super_block *sb,
167                                  struct ext4_super_block *es)
168 {
169         if (!ext4_has_feature_metadata_csum(sb))
170                 return 1;
171 
172         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
173 }
174 
175 static __le32 ext4_superblock_csum(struct super_block *sb,
176                                    struct ext4_super_block *es)
177 {
178         struct ext4_sb_info *sbi = EXT4_SB(sb);
179         int offset = offsetof(struct ext4_super_block, s_checksum);
180         __u32 csum;
181 
182         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
183 
184         return cpu_to_le32(csum);
185 }
186 
187 static int ext4_superblock_csum_verify(struct super_block *sb,
188                                        struct ext4_super_block *es)
189 {
190         if (!ext4_has_metadata_csum(sb))
191                 return 1;
192 
193         return es->s_checksum == ext4_superblock_csum(sb, es);
194 }
195 
196 void ext4_superblock_csum_set(struct super_block *sb)
197 {
198         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
199 
200         if (!ext4_has_metadata_csum(sb))
201                 return;
202 
203         es->s_checksum = ext4_superblock_csum(sb, es);
204 }
205 
206 void *ext4_kvmalloc(size_t size, gfp_t flags)
207 {
208         void *ret;
209 
210         ret = kmalloc(size, flags | __GFP_NOWARN);
211         if (!ret)
212                 ret = __vmalloc(size, flags, PAGE_KERNEL);
213         return ret;
214 }
215 
216 void *ext4_kvzalloc(size_t size, gfp_t flags)
217 {
218         void *ret;
219 
220         ret = kzalloc(size, flags | __GFP_NOWARN);
221         if (!ret)
222                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
223         return ret;
224 }
225 
226 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
227                                struct ext4_group_desc *bg)
228 {
229         return le32_to_cpu(bg->bg_block_bitmap_lo) |
230                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
231                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
232 }
233 
234 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
235                                struct ext4_group_desc *bg)
236 {
237         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
238                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
239                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
240 }
241 
242 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
243                               struct ext4_group_desc *bg)
244 {
245         return le32_to_cpu(bg->bg_inode_table_lo) |
246                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
247                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
248 }
249 
250 __u32 ext4_free_group_clusters(struct super_block *sb,
251                                struct ext4_group_desc *bg)
252 {
253         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
254                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
255                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
256 }
257 
258 __u32 ext4_free_inodes_count(struct super_block *sb,
259                               struct ext4_group_desc *bg)
260 {
261         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
262                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
263                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
264 }
265 
266 __u32 ext4_used_dirs_count(struct super_block *sb,
267                               struct ext4_group_desc *bg)
268 {
269         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
270                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
271                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
272 }
273 
274 __u32 ext4_itable_unused_count(struct super_block *sb,
275                               struct ext4_group_desc *bg)
276 {
277         return le16_to_cpu(bg->bg_itable_unused_lo) |
278                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
279                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
280 }
281 
282 void ext4_block_bitmap_set(struct super_block *sb,
283                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
284 {
285         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
286         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
287                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
288 }
289 
290 void ext4_inode_bitmap_set(struct super_block *sb,
291                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
292 {
293         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
294         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
295                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
296 }
297 
298 void ext4_inode_table_set(struct super_block *sb,
299                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
300 {
301         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
302         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
303                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
304 }
305 
306 void ext4_free_group_clusters_set(struct super_block *sb,
307                                   struct ext4_group_desc *bg, __u32 count)
308 {
309         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
310         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
311                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
312 }
313 
314 void ext4_free_inodes_set(struct super_block *sb,
315                           struct ext4_group_desc *bg, __u32 count)
316 {
317         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
318         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
319                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
320 }
321 
322 void ext4_used_dirs_set(struct super_block *sb,
323                           struct ext4_group_desc *bg, __u32 count)
324 {
325         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
326         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
327                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
328 }
329 
330 void ext4_itable_unused_set(struct super_block *sb,
331                           struct ext4_group_desc *bg, __u32 count)
332 {
333         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
334         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
335                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
336 }
337 
338 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
339 {
340         time64_t now = ktime_get_real_seconds();
341 
342         now = clamp_val(now, 0, (1ull << 40) - 1);
343 
344         *lo = cpu_to_le32(lower_32_bits(now));
345         *hi = upper_32_bits(now);
346 }
347 
348 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
349 {
350         return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
351 }
352 #define ext4_update_tstamp(es, tstamp) \
353         __ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
354 #define ext4_get_tstamp(es, tstamp) \
355         __ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
356 
357 static void __save_error_info(struct super_block *sb, const char *func,
358                             unsigned int line)
359 {
360         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
361 
362         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
363         if (bdev_read_only(sb->s_bdev))
364                 return;
365         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
366         ext4_update_tstamp(es, s_last_error_time);
367         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
368         es->s_last_error_line = cpu_to_le32(line);
369         if (!es->s_first_error_time) {
370                 es->s_first_error_time = es->s_last_error_time;
371                 es->s_first_error_time_hi = es->s_last_error_time_hi;
372                 strncpy(es->s_first_error_func, func,
373                         sizeof(es->s_first_error_func));
374                 es->s_first_error_line = cpu_to_le32(line);
375                 es->s_first_error_ino = es->s_last_error_ino;
376                 es->s_first_error_block = es->s_last_error_block;
377         }
378         /*
379          * Start the daily error reporting function if it hasn't been
380          * started already
381          */
382         if (!es->s_error_count)
383                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
384         le32_add_cpu(&es->s_error_count, 1);
385 }
386 
387 static void save_error_info(struct super_block *sb, const char *func,
388                             unsigned int line)
389 {
390         __save_error_info(sb, func, line);
391         ext4_commit_super(sb, 1);
392 }
393 
394 /*
395  * The del_gendisk() function uninitializes the disk-specific data
396  * structures, including the bdi structure, without telling anyone
397  * else.  Once this happens, any attempt to call mark_buffer_dirty()
398  * (for example, by ext4_commit_super), will cause a kernel OOPS.
399  * This is a kludge to prevent these oops until we can put in a proper
400  * hook in del_gendisk() to inform the VFS and file system layers.
401  */
402 static int block_device_ejected(struct super_block *sb)
403 {
404         struct inode *bd_inode = sb->s_bdev->bd_inode;
405         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
406 
407         return bdi->dev == NULL;
408 }
409 
410 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
411 {
412         struct super_block              *sb = journal->j_private;
413         struct ext4_sb_info             *sbi = EXT4_SB(sb);
414         int                             error = is_journal_aborted(journal);
415         struct ext4_journal_cb_entry    *jce;
416 
417         BUG_ON(txn->t_state == T_FINISHED);
418 
419         ext4_process_freed_data(sb, txn->t_tid);
420 
421         spin_lock(&sbi->s_md_lock);
422         while (!list_empty(&txn->t_private_list)) {
423                 jce = list_entry(txn->t_private_list.next,
424                                  struct ext4_journal_cb_entry, jce_list);
425                 list_del_init(&jce->jce_list);
426                 spin_unlock(&sbi->s_md_lock);
427                 jce->jce_func(sb, jce, error);
428                 spin_lock(&sbi->s_md_lock);
429         }
430         spin_unlock(&sbi->s_md_lock);
431 }
432 
433 static bool system_going_down(void)
434 {
435         return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
436                 || system_state == SYSTEM_RESTART;
437 }
438 
439 /* Deal with the reporting of failure conditions on a filesystem such as
440  * inconsistencies detected or read IO failures.
441  *
442  * On ext2, we can store the error state of the filesystem in the
443  * superblock.  That is not possible on ext4, because we may have other
444  * write ordering constraints on the superblock which prevent us from
445  * writing it out straight away; and given that the journal is about to
446  * be aborted, we can't rely on the current, or future, transactions to
447  * write out the superblock safely.
448  *
449  * We'll just use the jbd2_journal_abort() error code to record an error in
450  * the journal instead.  On recovery, the journal will complain about
451  * that error until we've noted it down and cleared it.
452  */
453 
454 static void ext4_handle_error(struct super_block *sb)
455 {
456         if (test_opt(sb, WARN_ON_ERROR))
457                 WARN_ON_ONCE(1);
458 
459         if (sb_rdonly(sb))
460                 return;
461 
462         if (!test_opt(sb, ERRORS_CONT)) {
463                 journal_t *journal = EXT4_SB(sb)->s_journal;
464 
465                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
466                 if (journal)
467                         jbd2_journal_abort(journal, -EIO);
468         }
469         /*
470          * We force ERRORS_RO behavior when system is rebooting. Otherwise we
471          * could panic during 'reboot -f' as the underlying device got already
472          * disabled.
473          */
474         if (test_opt(sb, ERRORS_RO) || system_going_down()) {
475                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
476                 /*
477                  * Make sure updated value of ->s_mount_flags will be visible
478                  * before ->s_flags update
479                  */
480                 smp_wmb();
481                 sb->s_flags |= SB_RDONLY;
482         } else if (test_opt(sb, ERRORS_PANIC)) {
483                 if (EXT4_SB(sb)->s_journal &&
484                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
485                         return;
486                 panic("EXT4-fs (device %s): panic forced after error\n",
487                         sb->s_id);
488         }
489 }
490 
491 #define ext4_error_ratelimit(sb)                                        \
492                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
493                              "EXT4-fs error")
494 
495 void __ext4_error(struct super_block *sb, const char *function,
496                   unsigned int line, const char *fmt, ...)
497 {
498         struct va_format vaf;
499         va_list args;
500 
501         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
502                 return;
503 
504         trace_ext4_error(sb, function, line);
505         if (ext4_error_ratelimit(sb)) {
506                 va_start(args, fmt);
507                 vaf.fmt = fmt;
508                 vaf.va = &args;
509                 printk(KERN_CRIT
510                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
511                        sb->s_id, function, line, current->comm, &vaf);
512                 va_end(args);
513         }
514         save_error_info(sb, function, line);
515         ext4_handle_error(sb);
516 }
517 
518 void __ext4_error_inode(struct inode *inode, const char *function,
519                         unsigned int line, ext4_fsblk_t block,
520                         const char *fmt, ...)
521 {
522         va_list args;
523         struct va_format vaf;
524         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
525 
526         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
527                 return;
528 
529         trace_ext4_error(inode->i_sb, function, line);
530         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
531         es->s_last_error_block = cpu_to_le64(block);
532         if (ext4_error_ratelimit(inode->i_sb)) {
533                 va_start(args, fmt);
534                 vaf.fmt = fmt;
535                 vaf.va = &args;
536                 if (block)
537                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
538                                "inode #%lu: block %llu: comm %s: %pV\n",
539                                inode->i_sb->s_id, function, line, inode->i_ino,
540                                block, current->comm, &vaf);
541                 else
542                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
543                                "inode #%lu: comm %s: %pV\n",
544                                inode->i_sb->s_id, function, line, inode->i_ino,
545                                current->comm, &vaf);
546                 va_end(args);
547         }
548         save_error_info(inode->i_sb, function, line);
549         ext4_handle_error(inode->i_sb);
550 }
551 
552 void __ext4_error_file(struct file *file, const char *function,
553                        unsigned int line, ext4_fsblk_t block,
554                        const char *fmt, ...)
555 {
556         va_list args;
557         struct va_format vaf;
558         struct ext4_super_block *es;
559         struct inode *inode = file_inode(file);
560         char pathname[80], *path;
561 
562         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
563                 return;
564 
565         trace_ext4_error(inode->i_sb, function, line);
566         es = EXT4_SB(inode->i_sb)->s_es;
567         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
568         if (ext4_error_ratelimit(inode->i_sb)) {
569                 path = file_path(file, pathname, sizeof(pathname));
570                 if (IS_ERR(path))
571                         path = "(unknown)";
572                 va_start(args, fmt);
573                 vaf.fmt = fmt;
574                 vaf.va = &args;
575                 if (block)
576                         printk(KERN_CRIT
577                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
578                                "block %llu: comm %s: path %s: %pV\n",
579                                inode->i_sb->s_id, function, line, inode->i_ino,
580                                block, current->comm, path, &vaf);
581                 else
582                         printk(KERN_CRIT
583                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
584                                "comm %s: path %s: %pV\n",
585                                inode->i_sb->s_id, function, line, inode->i_ino,
586                                current->comm, path, &vaf);
587                 va_end(args);
588         }
589         save_error_info(inode->i_sb, function, line);
590         ext4_handle_error(inode->i_sb);
591 }
592 
593 const char *ext4_decode_error(struct super_block *sb, int errno,
594                               char nbuf[16])
595 {
596         char *errstr = NULL;
597 
598         switch (errno) {
599         case -EFSCORRUPTED:
600                 errstr = "Corrupt filesystem";
601                 break;
602         case -EFSBADCRC:
603                 errstr = "Filesystem failed CRC";
604                 break;
605         case -EIO:
606                 errstr = "IO failure";
607                 break;
608         case -ENOMEM:
609                 errstr = "Out of memory";
610                 break;
611         case -EROFS:
612                 if (!sb || (EXT4_SB(sb)->s_journal &&
613                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
614                         errstr = "Journal has aborted";
615                 else
616                         errstr = "Readonly filesystem";
617                 break;
618         default:
619                 /* If the caller passed in an extra buffer for unknown
620                  * errors, textualise them now.  Else we just return
621                  * NULL. */
622                 if (nbuf) {
623                         /* Check for truncated error codes... */
624                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
625                                 errstr = nbuf;
626                 }
627                 break;
628         }
629 
630         return errstr;
631 }
632 
633 /* __ext4_std_error decodes expected errors from journaling functions
634  * automatically and invokes the appropriate error response.  */
635 
636 void __ext4_std_error(struct super_block *sb, const char *function,
637                       unsigned int line, int errno)
638 {
639         char nbuf[16];
640         const char *errstr;
641 
642         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
643                 return;
644 
645         /* Special case: if the error is EROFS, and we're not already
646          * inside a transaction, then there's really no point in logging
647          * an error. */
648         if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
649                 return;
650 
651         if (ext4_error_ratelimit(sb)) {
652                 errstr = ext4_decode_error(sb, errno, nbuf);
653                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
654                        sb->s_id, function, line, errstr);
655         }
656 
657         save_error_info(sb, function, line);
658         ext4_handle_error(sb);
659 }
660 
661 /*
662  * ext4_abort is a much stronger failure handler than ext4_error.  The
663  * abort function may be used to deal with unrecoverable failures such
664  * as journal IO errors or ENOMEM at a critical moment in log management.
665  *
666  * We unconditionally force the filesystem into an ABORT|READONLY state,
667  * unless the error response on the fs has been set to panic in which
668  * case we take the easy way out and panic immediately.
669  */
670 
671 void __ext4_abort(struct super_block *sb, const char *function,
672                 unsigned int line, const char *fmt, ...)
673 {
674         struct va_format vaf;
675         va_list args;
676 
677         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
678                 return;
679 
680         save_error_info(sb, function, line);
681         va_start(args, fmt);
682         vaf.fmt = fmt;
683         vaf.va = &args;
684         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
685                sb->s_id, function, line, &vaf);
686         va_end(args);
687 
688         if (sb_rdonly(sb) == 0) {
689                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
690                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
691                 /*
692                  * Make sure updated value of ->s_mount_flags will be visible
693                  * before ->s_flags update
694                  */
695                 smp_wmb();
696                 sb->s_flags |= SB_RDONLY;
697                 if (EXT4_SB(sb)->s_journal)
698                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
699                 save_error_info(sb, function, line);
700         }
701         if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
702                 if (EXT4_SB(sb)->s_journal &&
703                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
704                         return;
705                 panic("EXT4-fs panic from previous error\n");
706         }
707 }
708 
709 void __ext4_msg(struct super_block *sb,
710                 const char *prefix, const char *fmt, ...)
711 {
712         struct va_format vaf;
713         va_list args;
714 
715         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
716                 return;
717 
718         va_start(args, fmt);
719         vaf.fmt = fmt;
720         vaf.va = &args;
721         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
722         va_end(args);
723 }
724 
725 #define ext4_warning_ratelimit(sb)                                      \
726                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
727                              "EXT4-fs warning")
728 
729 void __ext4_warning(struct super_block *sb, const char *function,
730                     unsigned int line, const char *fmt, ...)
731 {
732         struct va_format vaf;
733         va_list args;
734 
735         if (!ext4_warning_ratelimit(sb))
736                 return;
737 
738         va_start(args, fmt);
739         vaf.fmt = fmt;
740         vaf.va = &args;
741         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
742                sb->s_id, function, line, &vaf);
743         va_end(args);
744 }
745 
746 void __ext4_warning_inode(const struct inode *inode, const char *function,
747                           unsigned int line, const char *fmt, ...)
748 {
749         struct va_format vaf;
750         va_list args;
751 
752         if (!ext4_warning_ratelimit(inode->i_sb))
753                 return;
754 
755         va_start(args, fmt);
756         vaf.fmt = fmt;
757         vaf.va = &args;
758         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
759                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
760                function, line, inode->i_ino, current->comm, &vaf);
761         va_end(args);
762 }
763 
764 void __ext4_grp_locked_error(const char *function, unsigned int line,
765                              struct super_block *sb, ext4_group_t grp,
766                              unsigned long ino, ext4_fsblk_t block,
767                              const char *fmt, ...)
768 __releases(bitlock)
769 __acquires(bitlock)
770 {
771         struct va_format vaf;
772         va_list args;
773         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
774 
775         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
776                 return;
777 
778         trace_ext4_error(sb, function, line);
779         es->s_last_error_ino = cpu_to_le32(ino);
780         es->s_last_error_block = cpu_to_le64(block);
781         __save_error_info(sb, function, line);
782 
783         if (ext4_error_ratelimit(sb)) {
784                 va_start(args, fmt);
785                 vaf.fmt = fmt;
786                 vaf.va = &args;
787                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
788                        sb->s_id, function, line, grp);
789                 if (ino)
790                         printk(KERN_CONT "inode %lu: ", ino);
791                 if (block)
792                         printk(KERN_CONT "block %llu:",
793                                (unsigned long long) block);
794                 printk(KERN_CONT "%pV\n", &vaf);
795                 va_end(args);
796         }
797 
798         if (test_opt(sb, WARN_ON_ERROR))
799                 WARN_ON_ONCE(1);
800 
801         if (test_opt(sb, ERRORS_CONT)) {
802                 ext4_commit_super(sb, 0);
803                 return;
804         }
805 
806         ext4_unlock_group(sb, grp);
807         ext4_commit_super(sb, 1);
808         ext4_handle_error(sb);
809         /*
810          * We only get here in the ERRORS_RO case; relocking the group
811          * may be dangerous, but nothing bad will happen since the
812          * filesystem will have already been marked read/only and the
813          * journal has been aborted.  We return 1 as a hint to callers
814          * who might what to use the return value from
815          * ext4_grp_locked_error() to distinguish between the
816          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
817          * aggressively from the ext4 function in question, with a
818          * more appropriate error code.
819          */
820         ext4_lock_group(sb, grp);
821         return;
822 }
823 
824 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
825                                      ext4_group_t group,
826                                      unsigned int flags)
827 {
828         struct ext4_sb_info *sbi = EXT4_SB(sb);
829         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
830         struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
831         int ret;
832 
833         if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
834                 ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
835                                             &grp->bb_state);
836                 if (!ret)
837                         percpu_counter_sub(&sbi->s_freeclusters_counter,
838                                            grp->bb_free);
839         }
840 
841         if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
842                 ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
843                                             &grp->bb_state);
844                 if (!ret && gdp) {
845                         int count;
846 
847                         count = ext4_free_inodes_count(sb, gdp);
848                         percpu_counter_sub(&sbi->s_freeinodes_counter,
849                                            count);
850                 }
851         }
852 }
853 
854 void ext4_update_dynamic_rev(struct super_block *sb)
855 {
856         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
857 
858         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
859                 return;
860 
861         ext4_warning(sb,
862                      "updating to rev %d because of new feature flag, "
863                      "running e2fsck is recommended",
864                      EXT4_DYNAMIC_REV);
865 
866         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
867         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
868         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
869         /* leave es->s_feature_*compat flags alone */
870         /* es->s_uuid will be set by e2fsck if empty */
871 
872         /*
873          * The rest of the superblock fields should be zero, and if not it
874          * means they are likely already in use, so leave them alone.  We
875          * can leave it up to e2fsck to clean up any inconsistencies there.
876          */
877 }
878 
879 /*
880  * Open the external journal device
881  */
882 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
883 {
884         struct block_device *bdev;
885         char b[BDEVNAME_SIZE];
886 
887         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
888         if (IS_ERR(bdev))
889                 goto fail;
890         return bdev;
891 
892 fail:
893         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
894                         __bdevname(dev, b), PTR_ERR(bdev));
895         return NULL;
896 }
897 
898 /*
899  * Release the journal device
900  */
901 static void ext4_blkdev_put(struct block_device *bdev)
902 {
903         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
904 }
905 
906 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
907 {
908         struct block_device *bdev;
909         bdev = sbi->journal_bdev;
910         if (bdev) {
911                 ext4_blkdev_put(bdev);
912                 sbi->journal_bdev = NULL;
913         }
914 }
915 
916 static inline struct inode *orphan_list_entry(struct list_head *l)
917 {
918         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
919 }
920 
921 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
922 {
923         struct list_head *l;
924 
925         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
926                  le32_to_cpu(sbi->s_es->s_last_orphan));
927 
928         printk(KERN_ERR "sb_info orphan list:\n");
929         list_for_each(l, &sbi->s_orphan) {
930                 struct inode *inode = orphan_list_entry(l);
931                 printk(KERN_ERR "  "
932                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
933                        inode->i_sb->s_id, inode->i_ino, inode,
934                        inode->i_mode, inode->i_nlink,
935                        NEXT_ORPHAN(inode));
936         }
937 }
938 
939 #ifdef CONFIG_QUOTA
940 static int ext4_quota_off(struct super_block *sb, int type);
941 
942 static inline void ext4_quota_off_umount(struct super_block *sb)
943 {
944         int type;
945 
946         /* Use our quota_off function to clear inode flags etc. */
947         for (type = 0; type < EXT4_MAXQUOTAS; type++)
948                 ext4_quota_off(sb, type);
949 }
950 
951 /*
952  * This is a helper function which is used in the mount/remount
953  * codepaths (which holds s_umount) to fetch the quota file name.
954  */
955 static inline char *get_qf_name(struct super_block *sb,
956                                 struct ext4_sb_info *sbi,
957                                 int type)
958 {
959         return rcu_dereference_protected(sbi->s_qf_names[type],
960                                          lockdep_is_held(&sb->s_umount));
961 }
962 #else
963 static inline void ext4_quota_off_umount(struct super_block *sb)
964 {
965 }
966 #endif
967 
968 static void ext4_put_super(struct super_block *sb)
969 {
970         struct ext4_sb_info *sbi = EXT4_SB(sb);
971         struct ext4_super_block *es = sbi->s_es;
972         int aborted = 0;
973         int i, err;
974 
975         ext4_unregister_li_request(sb);
976         ext4_quota_off_umount(sb);
977 
978         destroy_workqueue(sbi->rsv_conversion_wq);
979 
980         if (sbi->s_journal) {
981                 aborted = is_journal_aborted(sbi->s_journal);
982                 err = jbd2_journal_destroy(sbi->s_journal);
983                 sbi->s_journal = NULL;
984                 if ((err < 0) && !aborted)
985                         ext4_abort(sb, "Couldn't clean up the journal");
986         }
987 
988         ext4_unregister_sysfs(sb);
989         ext4_es_unregister_shrinker(sbi);
990         del_timer_sync(&sbi->s_err_report);
991         ext4_release_system_zone(sb);
992         ext4_mb_release(sb);
993         ext4_ext_release(sb);
994 
995         if (!sb_rdonly(sb) && !aborted) {
996                 ext4_clear_feature_journal_needs_recovery(sb);
997                 es->s_state = cpu_to_le16(sbi->s_mount_state);
998         }
999         if (!sb_rdonly(sb))
1000                 ext4_commit_super(sb, 1);
1001 
1002         for (i = 0; i < sbi->s_gdb_count; i++)
1003                 brelse(sbi->s_group_desc[i]);
1004         kvfree(sbi->s_group_desc);
1005         kvfree(sbi->s_flex_groups);
1006         percpu_counter_destroy(&sbi->s_freeclusters_counter);
1007         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1008         percpu_counter_destroy(&sbi->s_dirs_counter);
1009         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1010         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
1011 #ifdef CONFIG_QUOTA
1012         for (i = 0; i < EXT4_MAXQUOTAS; i++)
1013                 kfree(get_qf_name(sb, sbi, i));
1014 #endif
1015 
1016         /* Debugging code just in case the in-memory inode orphan list
1017          * isn't empty.  The on-disk one can be non-empty if we've
1018          * detected an error and taken the fs readonly, but the
1019          * in-memory list had better be clean by this point. */
1020         if (!list_empty(&sbi->s_orphan))
1021                 dump_orphan_list(sb, sbi);
1022         J_ASSERT(list_empty(&sbi->s_orphan));
1023 
1024         sync_blockdev(sb->s_bdev);
1025         invalidate_bdev(sb->s_bdev);
1026         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
1027                 /*
1028                  * Invalidate the journal device's buffers.  We don't want them
1029                  * floating about in memory - the physical journal device may
1030                  * hotswapped, and it breaks the `ro-after' testing code.
1031                  */
1032                 sync_blockdev(sbi->journal_bdev);
1033                 invalidate_bdev(sbi->journal_bdev);
1034                 ext4_blkdev_remove(sbi);
1035         }
1036 
1037         ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1038         sbi->s_ea_inode_cache = NULL;
1039 
1040         ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1041         sbi->s_ea_block_cache = NULL;
1042 
1043         if (sbi->s_mmp_tsk)
1044                 kthread_stop(sbi->s_mmp_tsk);
1045         brelse(sbi->s_sbh);
1046         sb->s_fs_info = NULL;
1047         /*
1048          * Now that we are completely done shutting down the
1049          * superblock, we need to actually destroy the kobject.
1050          */
1051         kobject_put(&sbi->s_kobj);
1052         wait_for_completion(&sbi->s_kobj_unregister);
1053         if (sbi->s_chksum_driver)
1054                 crypto_free_shash(sbi->s_chksum_driver);
1055         kfree(sbi->s_blockgroup_lock);
1056         fs_put_dax(sbi->s_daxdev);
1057         kfree(sbi);
1058 }
1059 
1060 static struct kmem_cache *ext4_inode_cachep;
1061 
1062 /*
1063  * Called inside transaction, so use GFP_NOFS
1064  */
1065 static struct inode *ext4_alloc_inode(struct super_block *sb)
1066 {
1067         struct ext4_inode_info *ei;
1068 
1069         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1070         if (!ei)
1071                 return NULL;
1072 
1073         inode_set_iversion(&ei->vfs_inode, 1);
1074         spin_lock_init(&ei->i_raw_lock);
1075         INIT_LIST_HEAD(&ei->i_prealloc_list);
1076         spin_lock_init(&ei->i_prealloc_lock);
1077         ext4_es_init_tree(&ei->i_es_tree);
1078         rwlock_init(&ei->i_es_lock);
1079         INIT_LIST_HEAD(&ei->i_es_list);
1080         ei->i_es_all_nr = 0;
1081         ei->i_es_shk_nr = 0;
1082         ei->i_es_shrink_lblk = 0;
1083         ei->i_reserved_data_blocks = 0;
1084         ei->i_da_metadata_calc_len = 0;
1085         ei->i_da_metadata_calc_last_lblock = 0;
1086         spin_lock_init(&(ei->i_block_reservation_lock));
1087         ext4_init_pending_tree(&ei->i_pending_tree);
1088 #ifdef CONFIG_QUOTA
1089         ei->i_reserved_quota = 0;
1090         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1091 #endif
1092         ei->jinode = NULL;
1093         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1094         spin_lock_init(&ei->i_completed_io_lock);
1095         ei->i_sync_tid = 0;
1096         ei->i_datasync_tid = 0;
1097         atomic_set(&ei->i_unwritten, 0);
1098         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1099         return &ei->vfs_inode;
1100 }
1101 
1102 static int ext4_drop_inode(struct inode *inode)
1103 {
1104         int drop = generic_drop_inode(inode);
1105 
1106         trace_ext4_drop_inode(inode, drop);
1107         return drop;
1108 }
1109 
1110 static void ext4_i_callback(struct rcu_head *head)
1111 {
1112         struct inode *inode = container_of(head, struct inode, i_rcu);
1113         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1114 }
1115 
1116 static void ext4_destroy_inode(struct inode *inode)
1117 {
1118         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1119                 ext4_msg(inode->i_sb, KERN_ERR,
1120                          "Inode %lu (%p): orphan list check failed!",
1121                          inode->i_ino, EXT4_I(inode));
1122                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1123                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
1124                                 true);
1125                 dump_stack();
1126         }
1127         call_rcu(&inode->i_rcu, ext4_i_callback);
1128 }
1129 
1130 static void init_once(void *foo)
1131 {
1132         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1133 
1134         INIT_LIST_HEAD(&ei->i_orphan);
1135         init_rwsem(&ei->xattr_sem);
1136         init_rwsem(&ei->i_data_sem);
1137         init_rwsem(&ei->i_mmap_sem);
1138         inode_init_once(&ei->vfs_inode);
1139 }
1140 
1141 static int __init init_inodecache(void)
1142 {
1143         ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1144                                 sizeof(struct ext4_inode_info), 0,
1145                                 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1146                                         SLAB_ACCOUNT),
1147                                 offsetof(struct ext4_inode_info, i_data),
1148                                 sizeof_field(struct ext4_inode_info, i_data),
1149                                 init_once);
1150         if (ext4_inode_cachep == NULL)
1151                 return -ENOMEM;
1152         return 0;
1153 }
1154 
1155 static void destroy_inodecache(void)
1156 {
1157         /*
1158          * Make sure all delayed rcu free inodes are flushed before we
1159          * destroy cache.
1160          */
1161         rcu_barrier();
1162         kmem_cache_destroy(ext4_inode_cachep);
1163 }
1164 
1165 void ext4_clear_inode(struct inode *inode)
1166 {
1167         invalidate_inode_buffers(inode);
1168         clear_inode(inode);
1169         dquot_drop(inode);
1170         ext4_discard_preallocations(inode);
1171         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1172         if (EXT4_I(inode)->jinode) {
1173                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1174                                                EXT4_I(inode)->jinode);
1175                 jbd2_free_inode(EXT4_I(inode)->jinode);
1176                 EXT4_I(inode)->jinode = NULL;
1177         }
1178         fscrypt_put_encryption_info(inode);
1179 }
1180 
1181 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1182                                         u64 ino, u32 generation)
1183 {
1184         struct inode *inode;
1185 
1186         /*
1187          * Currently we don't know the generation for parent directory, so
1188          * a generation of 0 means "accept any"
1189          */
1190         inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1191         if (IS_ERR(inode))
1192                 return ERR_CAST(inode);
1193         if (generation && inode->i_generation != generation) {
1194                 iput(inode);
1195                 return ERR_PTR(-ESTALE);
1196         }
1197 
1198         return inode;
1199 }
1200 
1201 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1202                                         int fh_len, int fh_type)
1203 {
1204         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1205                                     ext4_nfs_get_inode);
1206 }
1207 
1208 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1209                                         int fh_len, int fh_type)
1210 {
1211         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1212                                     ext4_nfs_get_inode);
1213 }
1214 
1215 static int ext4_nfs_commit_metadata(struct inode *inode)
1216 {
1217         struct writeback_control wbc = {
1218                 .sync_mode = WB_SYNC_ALL
1219         };
1220 
1221         trace_ext4_nfs_commit_metadata(inode);
1222         return ext4_write_inode(inode, &wbc);
1223 }
1224 
1225 /*
1226  * Try to release metadata pages (indirect blocks, directories) which are
1227  * mapped via the block device.  Since these pages could have journal heads
1228  * which would prevent try_to_free_buffers() from freeing them, we must use
1229  * jbd2 layer's try_to_free_buffers() function to release them.
1230  */
1231 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1232                                  gfp_t wait)
1233 {
1234         journal_t *journal = EXT4_SB(sb)->s_journal;
1235 
1236         WARN_ON(PageChecked(page));
1237         if (!page_has_buffers(page))
1238                 return 0;
1239         if (journal)
1240                 return jbd2_journal_try_to_free_buffers(journal, page,
1241                                                 wait & ~__GFP_DIRECT_RECLAIM);
1242         return try_to_free_buffers(page);
1243 }
1244 
1245 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1246 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1247 {
1248         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1249                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1250 }
1251 
1252 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1253                                                         void *fs_data)
1254 {
1255         handle_t *handle = fs_data;
1256         int res, res2, credits, retries = 0;
1257 
1258         /*
1259          * Encrypting the root directory is not allowed because e2fsck expects
1260          * lost+found to exist and be unencrypted, and encrypting the root
1261          * directory would imply encrypting the lost+found directory as well as
1262          * the filename "lost+found" itself.
1263          */
1264         if (inode->i_ino == EXT4_ROOT_INO)
1265                 return -EPERM;
1266 
1267         if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1268                 return -EINVAL;
1269 
1270         res = ext4_convert_inline_data(inode);
1271         if (res)
1272                 return res;
1273 
1274         /*
1275          * If a journal handle was specified, then the encryption context is
1276          * being set on a new inode via inheritance and is part of a larger
1277          * transaction to create the inode.  Otherwise the encryption context is
1278          * being set on an existing inode in its own transaction.  Only in the
1279          * latter case should the "retry on ENOSPC" logic be used.
1280          */
1281 
1282         if (handle) {
1283                 res = ext4_xattr_set_handle(handle, inode,
1284                                             EXT4_XATTR_INDEX_ENCRYPTION,
1285                                             EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1286                                             ctx, len, 0);
1287                 if (!res) {
1288                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1289                         ext4_clear_inode_state(inode,
1290                                         EXT4_STATE_MAY_INLINE_DATA);
1291                         /*
1292                          * Update inode->i_flags - S_ENCRYPTED will be enabled,
1293                          * S_DAX may be disabled
1294                          */
1295                         ext4_set_inode_flags(inode);
1296                 }
1297                 return res;
1298         }
1299 
1300         res = dquot_initialize(inode);
1301         if (res)
1302                 return res;
1303 retry:
1304         res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1305                                      &credits);
1306         if (res)
1307                 return res;
1308 
1309         handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1310         if (IS_ERR(handle))
1311                 return PTR_ERR(handle);
1312 
1313         res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1314                                     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1315                                     ctx, len, 0);
1316         if (!res) {
1317                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1318                 /*
1319                  * Update inode->i_flags - S_ENCRYPTED will be enabled,
1320                  * S_DAX may be disabled
1321                  */
1322                 ext4_set_inode_flags(inode);
1323                 res = ext4_mark_inode_dirty(handle, inode);
1324                 if (res)
1325                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1326         }
1327         res2 = ext4_journal_stop(handle);
1328 
1329         if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1330                 goto retry;
1331         if (!res)
1332                 res = res2;
1333         return res;
1334 }
1335 
1336 static bool ext4_dummy_context(struct inode *inode)
1337 {
1338         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1339 }
1340 
1341 static const struct fscrypt_operations ext4_cryptops = {
1342         .key_prefix             = "ext4:",
1343         .get_context            = ext4_get_context,
1344         .set_context            = ext4_set_context,
1345         .dummy_context          = ext4_dummy_context,
1346         .empty_dir              = ext4_empty_dir,
1347         .max_namelen            = EXT4_NAME_LEN,
1348 };
1349 #endif
1350 
1351 #ifdef CONFIG_QUOTA
1352 static const char * const quotatypes[] = INITQFNAMES;
1353 #define QTYPE2NAME(t) (quotatypes[t])
1354 
1355 static int ext4_write_dquot(struct dquot *dquot);
1356 static int ext4_acquire_dquot(struct dquot *dquot);
1357 static int ext4_release_dquot(struct dquot *dquot);
1358 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1359 static int ext4_write_info(struct super_block *sb, int type);
1360 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1361                          const struct path *path);
1362 static int ext4_quota_on_mount(struct super_block *sb, int type);
1363 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1364                                size_t len, loff_t off);
1365 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1366                                 const char *data, size_t len, loff_t off);
1367 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1368                              unsigned int flags);
1369 static int ext4_enable_quotas(struct super_block *sb);
1370 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1371 
1372 static struct dquot **ext4_get_dquots(struct inode *inode)
1373 {
1374         return EXT4_I(inode)->i_dquot;
1375 }
1376 
1377 static const struct dquot_operations ext4_quota_operations = {
1378         .get_reserved_space     = ext4_get_reserved_space,
1379         .write_dquot            = ext4_write_dquot,
1380         .acquire_dquot          = ext4_acquire_dquot,
1381         .release_dquot          = ext4_release_dquot,
1382         .mark_dirty             = ext4_mark_dquot_dirty,
1383         .write_info             = ext4_write_info,
1384         .alloc_dquot            = dquot_alloc,
1385         .destroy_dquot          = dquot_destroy,
1386         .get_projid             = ext4_get_projid,
1387         .get_inode_usage        = ext4_get_inode_usage,
1388         .get_next_id            = ext4_get_next_id,
1389 };
1390 
1391 static const struct quotactl_ops ext4_qctl_operations = {
1392         .quota_on       = ext4_quota_on,
1393         .quota_off      = ext4_quota_off,
1394         .quota_sync     = dquot_quota_sync,
1395         .get_state      = dquot_get_state,
1396         .set_info       = dquot_set_dqinfo,
1397         .get_dqblk      = dquot_get_dqblk,
1398         .set_dqblk      = dquot_set_dqblk,
1399         .get_nextdqblk  = dquot_get_next_dqblk,
1400 };
1401 #endif
1402 
1403 static const struct super_operations ext4_sops = {
1404         .alloc_inode    = ext4_alloc_inode,
1405         .destroy_inode  = ext4_destroy_inode,
1406         .write_inode    = ext4_write_inode,
1407         .dirty_inode    = ext4_dirty_inode,
1408         .drop_inode     = ext4_drop_inode,
1409         .evict_inode    = ext4_evict_inode,
1410         .put_super      = ext4_put_super,
1411         .sync_fs        = ext4_sync_fs,
1412         .freeze_fs      = ext4_freeze,
1413         .unfreeze_fs    = ext4_unfreeze,
1414         .statfs         = ext4_statfs,
1415         .remount_fs     = ext4_remount,
1416         .show_options   = ext4_show_options,
1417 #ifdef CONFIG_QUOTA
1418         .quota_read     = ext4_quota_read,
1419         .quota_write    = ext4_quota_write,
1420         .get_dquots     = ext4_get_dquots,
1421 #endif
1422         .bdev_try_to_free_page = bdev_try_to_free_page,
1423 };
1424 
1425 static const struct export_operations ext4_export_ops = {
1426         .fh_to_dentry = ext4_fh_to_dentry,
1427         .fh_to_parent = ext4_fh_to_parent,
1428         .get_parent = ext4_get_parent,
1429         .commit_metadata = ext4_nfs_commit_metadata,
1430 };
1431 
1432 enum {
1433         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1434         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1435         Opt_nouid32, Opt_debug, Opt_removed,
1436         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1437         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1438         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1439         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1440         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1441         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1442         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1443         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1444         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1445         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1446         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1447         Opt_nowarn_on_error, Opt_mblk_io_submit,
1448         Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1449         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1450         Opt_inode_readahead_blks, Opt_journal_ioprio,
1451         Opt_dioread_nolock, Opt_dioread_lock,
1452         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1453         Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1454 };
1455 
1456 static const match_table_t tokens = {
1457         {Opt_bsd_df, "bsddf"},
1458         {Opt_minix_df, "minixdf"},
1459         {Opt_grpid, "grpid"},
1460         {Opt_grpid, "bsdgroups"},
1461         {Opt_nogrpid, "nogrpid"},
1462         {Opt_nogrpid, "sysvgroups"},
1463         {Opt_resgid, "resgid=%u"},
1464         {Opt_resuid, "resuid=%u"},
1465         {Opt_sb, "sb=%u"},
1466         {Opt_err_cont, "errors=continue"},
1467         {Opt_err_panic, "errors=panic"},
1468         {Opt_err_ro, "errors=remount-ro"},
1469         {Opt_nouid32, "nouid32"},
1470         {Opt_debug, "debug"},
1471         {Opt_removed, "oldalloc"},
1472         {Opt_removed, "orlov"},
1473         {Opt_user_xattr, "user_xattr"},
1474         {Opt_nouser_xattr, "nouser_xattr"},
1475         {Opt_acl, "acl"},
1476         {Opt_noacl, "noacl"},
1477         {Opt_noload, "norecovery"},
1478         {Opt_noload, "noload"},
1479         {Opt_removed, "nobh"},
1480         {Opt_removed, "bh"},
1481         {Opt_commit, "commit=%u"},
1482         {Opt_min_batch_time, "min_batch_time=%u"},
1483         {Opt_max_batch_time, "max_batch_time=%u"},
1484         {Opt_journal_dev, "journal_dev=%u"},
1485         {Opt_journal_path, "journal_path=%s"},
1486         {Opt_journal_checksum, "journal_checksum"},
1487         {Opt_nojournal_checksum, "nojournal_checksum"},
1488         {Opt_journal_async_commit, "journal_async_commit"},
1489         {Opt_abort, "abort"},
1490         {Opt_data_journal, "data=journal"},
1491         {Opt_data_ordered, "data=ordered"},
1492         {Opt_data_writeback, "data=writeback"},
1493         {Opt_data_err_abort, "data_err=abort"},
1494         {Opt_data_err_ignore, "data_err=ignore"},
1495         {Opt_offusrjquota, "usrjquota="},
1496         {Opt_usrjquota, "usrjquota=%s"},
1497         {Opt_offgrpjquota, "grpjquota="},
1498         {Opt_grpjquota, "grpjquota=%s"},
1499         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1500         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1501         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1502         {Opt_grpquota, "grpquota"},
1503         {Opt_noquota, "noquota"},
1504         {Opt_quota, "quota"},
1505         {Opt_usrquota, "usrquota"},
1506         {Opt_prjquota, "prjquota"},
1507         {Opt_barrier, "barrier=%u"},
1508         {Opt_barrier, "barrier"},
1509         {Opt_nobarrier, "nobarrier"},
1510         {Opt_i_version, "i_version"},
1511         {Opt_dax, "dax"},
1512         {Opt_stripe, "stripe=%u"},
1513         {Opt_delalloc, "delalloc"},
1514         {Opt_warn_on_error, "warn_on_error"},
1515         {Opt_nowarn_on_error, "nowarn_on_error"},
1516         {Opt_lazytime, "lazytime"},
1517         {Opt_nolazytime, "nolazytime"},
1518         {Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1519         {Opt_nodelalloc, "nodelalloc"},
1520         {Opt_removed, "mblk_io_submit"},
1521         {Opt_removed, "nomblk_io_submit"},
1522         {Opt_block_validity, "block_validity"},
1523         {Opt_noblock_validity, "noblock_validity"},
1524         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1525         {Opt_journal_ioprio, "journal_ioprio=%u"},
1526         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1527         {Opt_auto_da_alloc, "auto_da_alloc"},
1528         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1529         {Opt_dioread_nolock, "dioread_nolock"},
1530         {Opt_dioread_lock, "dioread_lock"},
1531         {Opt_discard, "discard"},
1532         {Opt_nodiscard, "nodiscard"},
1533         {Opt_init_itable, "init_itable=%u"},
1534         {Opt_init_itable, "init_itable"},
1535         {Opt_noinit_itable, "noinit_itable"},
1536         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1537         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1538         {Opt_nombcache, "nombcache"},
1539         {Opt_nombcache, "no_mbcache"},  /* for backward compatibility */
1540         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1541         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1542         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1543         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1544         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1545         {Opt_err, NULL},
1546 };
1547 
1548 static ext4_fsblk_t get_sb_block(void **data)
1549 {
1550         ext4_fsblk_t    sb_block;
1551         char            *options = (char *) *data;
1552 
1553         if (!options || strncmp(options, "sb=", 3) != 0)
1554                 return 1;       /* Default location */
1555 
1556         options += 3;
1557         /* TODO: use simple_strtoll with >32bit ext4 */
1558         sb_block = simple_strtoul(options, &options, 0);
1559         if (*options && *options != ',') {
1560                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1561                        (char *) *data);
1562                 return 1;
1563         }
1564         if (*options == ',')
1565                 options++;
1566         *data = (void *) options;
1567 
1568         return sb_block;
1569 }
1570 
1571 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1572 static const char deprecated_msg[] =
1573         "Mount option \"%s\" will be removed by %s\n"
1574         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1575 
1576 #ifdef CONFIG_QUOTA
1577 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1578 {
1579         struct ext4_sb_info *sbi = EXT4_SB(sb);
1580         char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1581         int ret = -1;
1582 
1583         if (sb_any_quota_loaded(sb) && !old_qname) {
1584                 ext4_msg(sb, KERN_ERR,
1585                         "Cannot change journaled "
1586                         "quota options when quota turned on");
1587                 return -1;
1588         }
1589         if (ext4_has_feature_quota(sb)) {
1590                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1591                          "ignored when QUOTA feature is enabled");
1592                 return 1;
1593         }
1594         qname = match_strdup(args);
1595         if (!qname) {
1596                 ext4_msg(sb, KERN_ERR,
1597                         "Not enough memory for storing quotafile name");
1598                 return -1;
1599         }
1600         if (old_qname) {
1601                 if (strcmp(old_qname, qname) == 0)
1602                         ret = 1;
1603                 else
1604                         ext4_msg(sb, KERN_ERR,
1605                                  "%s quota file already specified",
1606                                  QTYPE2NAME(qtype));
1607                 goto errout;
1608         }
1609         if (strchr(qname, '/')) {
1610                 ext4_msg(sb, KERN_ERR,
1611                         "quotafile must be on filesystem root");
1612                 goto errout;
1613         }
1614         rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1615         set_opt(sb, QUOTA);
1616         return 1;
1617 errout:
1618         kfree(qname);
1619         return ret;
1620 }
1621 
1622 static int clear_qf_name(struct super_block *sb, int qtype)
1623 {
1624 
1625         struct ext4_sb_info *sbi = EXT4_SB(sb);
1626         char *old_qname = get_qf_name(sb, sbi, qtype);
1627 
1628         if (sb_any_quota_loaded(sb) && old_qname) {
1629                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1630                         " when quota turned on");
1631                 return -1;
1632         }
1633         rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1634         synchronize_rcu();
1635         kfree(old_qname);
1636         return 1;
1637 }
1638 #endif
1639 
1640 #define MOPT_SET        0x0001
1641 #define MOPT_CLEAR      0x0002
1642 #define MOPT_NOSUPPORT  0x0004
1643 #define MOPT_EXPLICIT   0x0008
1644 #define MOPT_CLEAR_ERR  0x0010
1645 #define MOPT_GTE0       0x0020
1646 #ifdef CONFIG_QUOTA
1647 #define MOPT_Q          0
1648 #define MOPT_QFMT       0x0040
1649 #else
1650 #define MOPT_Q          MOPT_NOSUPPORT
1651 #define MOPT_QFMT       MOPT_NOSUPPORT
1652 #endif
1653 #define MOPT_DATAJ      0x0080
1654 #define MOPT_NO_EXT2    0x0100
1655 #define MOPT_NO_EXT3    0x0200
1656 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1657 #define MOPT_STRING     0x0400
1658 
1659 static const struct mount_opts {
1660         int     token;
1661         int     mount_opt;
1662         int     flags;
1663 } ext4_mount_opts[] = {
1664         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1665         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1666         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1667         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1668         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1669         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1670         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1671          MOPT_EXT4_ONLY | MOPT_SET},
1672         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1673          MOPT_EXT4_ONLY | MOPT_CLEAR},
1674         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1675         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1676         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1677          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1678         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1679          MOPT_EXT4_ONLY | MOPT_CLEAR},
1680         {Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1681         {Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1682         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1683          MOPT_EXT4_ONLY | MOPT_CLEAR},
1684         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1685          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1686         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1687                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1688          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1689         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1690         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1691         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1692         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1693         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1694          MOPT_NO_EXT2},
1695         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1696          MOPT_NO_EXT2},
1697         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1698         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1699         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1700         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1701         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1702         {Opt_commit, 0, MOPT_GTE0},
1703         {Opt_max_batch_time, 0, MOPT_GTE0},
1704         {Opt_min_batch_time, 0, MOPT_GTE0},
1705         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1706         {Opt_init_itable, 0, MOPT_GTE0},
1707         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1708         {Opt_stripe, 0, MOPT_GTE0},
1709         {Opt_resuid, 0, MOPT_GTE0},
1710         {Opt_resgid, 0, MOPT_GTE0},
1711         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1712         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1713         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1714         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1715         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1716         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1717          MOPT_NO_EXT2 | MOPT_DATAJ},
1718         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1719         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1720 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1721         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1722         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1723 #else
1724         {Opt_acl, 0, MOPT_NOSUPPORT},
1725         {Opt_noacl, 0, MOPT_NOSUPPORT},
1726 #endif
1727         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1728         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1729         {Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1730         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1731         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1732                                                         MOPT_SET | MOPT_Q},
1733         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1734                                                         MOPT_SET | MOPT_Q},
1735         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1736                                                         MOPT_SET | MOPT_Q},
1737         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1738                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1739                                                         MOPT_CLEAR | MOPT_Q},
1740         {Opt_usrjquota, 0, MOPT_Q},
1741         {Opt_grpjquota, 0, MOPT_Q},
1742         {Opt_offusrjquota, 0, MOPT_Q},
1743         {Opt_offgrpjquota, 0, MOPT_Q},
1744         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1745         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1746         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1747         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1748         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1749         {Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1750         {Opt_err, 0, 0}
1751 };
1752 
1753 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1754                             substring_t *args, unsigned long *journal_devnum,
1755                             unsigned int *journal_ioprio, int is_remount)
1756 {
1757         struct ext4_sb_info *sbi = EXT4_SB(sb);
1758         const struct mount_opts *m;
1759         kuid_t uid;
1760         kgid_t gid;
1761         int arg = 0;
1762 
1763 #ifdef CONFIG_QUOTA
1764         if (token == Opt_usrjquota)
1765                 return set_qf_name(sb, USRQUOTA, &args[0]);
1766         else if (token == Opt_grpjquota)
1767                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1768         else if (token == Opt_offusrjquota)
1769                 return clear_qf_name(sb, USRQUOTA);
1770         else if (token == Opt_offgrpjquota)
1771                 return clear_qf_name(sb, GRPQUOTA);
1772 #endif
1773         switch (token) {
1774         case Opt_noacl:
1775         case Opt_nouser_xattr:
1776                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1777                 break;
1778         case Opt_sb:
1779                 return 1;       /* handled by get_sb_block() */
1780         case Opt_removed:
1781                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1782                 return 1;
1783         case Opt_abort:
1784                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1785                 return 1;
1786         case Opt_i_version:
1787                 sb->s_flags |= SB_I_VERSION;
1788                 return 1;
1789         case Opt_lazytime:
1790                 sb->s_flags |= SB_LAZYTIME;
1791                 return 1;
1792         case Opt_nolazytime:
1793                 sb->s_flags &= ~SB_LAZYTIME;
1794                 return 1;
1795         }
1796 
1797         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1798                 if (token == m->token)
1799                         break;
1800 
1801         if (m->token == Opt_err) {
1802                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1803                          "or missing value", opt);
1804                 return -1;
1805         }
1806 
1807         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1808                 ext4_msg(sb, KERN_ERR,
1809                          "Mount option \"%s\" incompatible with ext2", opt);
1810                 return -1;
1811         }
1812         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1813                 ext4_msg(sb, KERN_ERR,
1814                          "Mount option \"%s\" incompatible with ext3", opt);
1815                 return -1;
1816         }
1817 
1818         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1819                 return -1;
1820         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1821                 return -1;
1822         if (m->flags & MOPT_EXPLICIT) {
1823                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1824                         set_opt2(sb, EXPLICIT_DELALLOC);
1825                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1826                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1827                 } else
1828                         return -1;
1829         }
1830         if (m->flags & MOPT_CLEAR_ERR)
1831                 clear_opt(sb, ERRORS_MASK);
1832         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1833                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1834                          "options when quota turned on");
1835                 return -1;
1836         }
1837 
1838         if (m->flags & MOPT_NOSUPPORT) {
1839                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1840         } else if (token == Opt_commit) {
1841                 if (arg == 0)
1842                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1843                 sbi->s_commit_interval = HZ * arg;
1844         } else if (token == Opt_debug_want_extra_isize) {
1845                 sbi->s_want_extra_isize = arg;
1846         } else if (token == Opt_max_batch_time) {
1847                 sbi->s_max_batch_time = arg;
1848         } else if (token == Opt_min_batch_time) {
1849                 sbi->s_min_batch_time = arg;
1850         } else if (token == Opt_inode_readahead_blks) {
1851                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1852                         ext4_msg(sb, KERN_ERR,
1853                                  "EXT4-fs: inode_readahead_blks must be "
1854                                  "0 or a power of 2 smaller than 2^31");
1855                         return -1;
1856                 }
1857                 sbi->s_inode_readahead_blks = arg;
1858         } else if (token == Opt_init_itable) {
1859                 set_opt(sb, INIT_INODE_TABLE);
1860                 if (!args->from)
1861                         arg = EXT4_DEF_LI_WAIT_MULT;
1862                 sbi->s_li_wait_mult = arg;
1863         } else if (token == Opt_max_dir_size_kb) {
1864                 sbi->s_max_dir_size_kb = arg;
1865         } else if (token == Opt_stripe) {
1866                 sbi->s_stripe = arg;
1867         } else if (token == Opt_resuid) {
1868                 uid = make_kuid(current_user_ns(), arg);
1869                 if (!uid_valid(uid)) {
1870                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1871                         return -1;
1872                 }
1873                 sbi->s_resuid = uid;
1874         } else if (token == Opt_resgid) {
1875                 gid = make_kgid(current_user_ns(), arg);
1876                 if (!gid_valid(gid)) {
1877                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1878                         return -1;
1879                 }
1880                 sbi->s_resgid = gid;
1881         } else if (token == Opt_journal_dev) {
1882                 if (is_remount) {
1883                         ext4_msg(sb, KERN_ERR,
1884                                  "Cannot specify journal on remount");
1885                         return -1;
1886                 }
1887                 *journal_devnum = arg;
1888         } else if (token == Opt_journal_path) {
1889                 char *journal_path;
1890                 struct inode *journal_inode;
1891                 struct path path;
1892                 int error;
1893 
1894                 if (is_remount) {
1895                         ext4_msg(sb, KERN_ERR,
1896                                  "Cannot specify journal on remount");
1897                         return -1;
1898                 }
1899                 journal_path = match_strdup(&args[0]);
1900                 if (!journal_path) {
1901                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1902                                 "journal device string");
1903                         return -1;
1904                 }
1905 
1906                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1907                 if (error) {
1908                         ext4_msg(sb, KERN_ERR, "error: could not find "
1909                                 "journal device path: error %d", error);
1910                         kfree(journal_path);
1911                         return -1;
1912                 }
1913 
1914                 journal_inode = d_inode(path.dentry);
1915                 if (!S_ISBLK(journal_inode->i_mode)) {
1916                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1917                                 "is not a block device", journal_path);
1918                         path_put(&path);
1919                         kfree(journal_path);
1920                         return -1;
1921                 }
1922 
1923                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1924                 path_put(&path);
1925                 kfree(journal_path);
1926         } else if (token == Opt_journal_ioprio) {
1927                 if (arg > 7) {
1928                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1929                                  " (must be 0-7)");
1930                         return -1;
1931                 }
1932                 *journal_ioprio =
1933                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1934         } else if (token == Opt_test_dummy_encryption) {
1935 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1936                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1937                 ext4_msg(sb, KERN_WARNING,
1938                          "Test dummy encryption mode enabled");
1939 #else
1940                 ext4_msg(sb, KERN_WARNING,
1941                          "Test dummy encryption mount option ignored");
1942 #endif
1943         } else if (m->flags & MOPT_DATAJ) {
1944                 if (is_remount) {
1945                         if (!sbi->s_journal)
1946                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1947                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1948                                 ext4_msg(sb, KERN_ERR,
1949                                          "Cannot change data mode on remount");
1950                                 return -1;
1951                         }
1952                 } else {
1953                         clear_opt(sb, DATA_FLAGS);
1954                         sbi->s_mount_opt |= m->mount_opt;
1955                 }
1956 #ifdef CONFIG_QUOTA
1957         } else if (m->flags & MOPT_QFMT) {
1958                 if (sb_any_quota_loaded(sb) &&
1959                     sbi->s_jquota_fmt != m->mount_opt) {
1960                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1961                                  "quota options when quota turned on");
1962                         return -1;
1963                 }
1964                 if (ext4_has_feature_quota(sb)) {
1965                         ext4_msg(sb, KERN_INFO,
1966                                  "Quota format mount options ignored "
1967                                  "when QUOTA feature is enabled");
1968                         return 1;
1969                 }
1970                 sbi->s_jquota_fmt = m->mount_opt;
1971 #endif
1972         } else if (token == Opt_dax) {
1973 #ifdef CONFIG_FS_DAX
1974                 ext4_msg(sb, KERN_WARNING,
1975                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1976                 sbi->s_mount_opt |= m->mount_opt;
1977 #else
1978                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1979                 return -1;
1980 #endif
1981         } else if (token == Opt_data_err_abort) {
1982                 sbi->s_mount_opt |= m->mount_opt;
1983         } else if (token == Opt_data_err_ignore) {
1984                 sbi->s_mount_opt &= ~m->mount_opt;
1985         } else {
1986                 if (!args->from)
1987                         arg = 1;
1988                 if (m->flags & MOPT_CLEAR)
1989                         arg = !arg;
1990                 else if (unlikely(!(m->flags & MOPT_SET))) {
1991                         ext4_msg(sb, KERN_WARNING,
1992                                  "buggy handling of option %s", opt);
1993                         WARN_ON(1);
1994                         return -1;
1995                 }
1996                 if (arg != 0)
1997                         sbi->s_mount_opt |= m->mount_opt;
1998                 else
1999                         sbi->s_mount_opt &= ~m->mount_opt;
2000         }
2001         return 1;
2002 }
2003 
2004 static int parse_options(char *options, struct super_block *sb,
2005                          unsigned long *journal_devnum,
2006                          unsigned int *journal_ioprio,
2007                          int is_remount)
2008 {
2009         struct ext4_sb_info *sbi = EXT4_SB(sb);
2010         char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2011         substring_t args[MAX_OPT_ARGS];
2012         int token;
2013 
2014         if (!options)
2015                 return 1;
2016 
2017         while ((p = strsep(&options, ",")) != NULL) {
2018                 if (!*p)
2019                         continue;
2020                 /*
2021                  * Initialize args struct so we know whether arg was
2022                  * found; some options take optional arguments.
2023                  */
2024                 args[0].to = args[0].from = NULL;
2025                 token = match_token(p, tokens, args);
2026                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
2027                                      journal_ioprio, is_remount) < 0)
2028                         return 0;
2029         }
2030 #ifdef CONFIG_QUOTA
2031         /*
2032          * We do the test below only for project quotas. 'usrquota' and
2033          * 'grpquota' mount options are allowed even without quota feature
2034          * to support legacy quotas in quota files.
2035          */
2036         if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2037                 ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2038                          "Cannot enable project quota enforcement.");
2039                 return 0;
2040         }
2041         usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2042         grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2043         if (usr_qf_name || grp_qf_name) {
2044                 if (test_opt(sb, USRQUOTA) && usr_qf_name)
2045                         clear_opt(sb, USRQUOTA);
2046 
2047                 if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2048                         clear_opt(sb, GRPQUOTA);
2049 
2050                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2051                         ext4_msg(sb, KERN_ERR, "old and new quota "
2052                                         "format mixing");
2053                         return 0;
2054                 }
2055 
2056                 if (!sbi->s_jquota_fmt) {
2057                         ext4_msg(sb, KERN_ERR, "journaled quota format "
2058                                         "not specified");
2059                         return 0;
2060                 }
2061         }
2062 #endif
2063         if (test_opt(sb, DIOREAD_NOLOCK)) {
2064                 int blocksize =
2065                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2066 
2067                 if (blocksize < PAGE_SIZE) {
2068                         ext4_msg(sb, KERN_ERR, "can't mount with "
2069                                  "dioread_nolock if block size != PAGE_SIZE");
2070                         return 0;
2071                 }
2072         }
2073         return 1;
2074 }
2075 
2076 static inline void ext4_show_quota_options(struct seq_file *seq,
2077                                            struct super_block *sb)
2078 {
2079 #if defined(CONFIG_QUOTA)
2080         struct ext4_sb_info *sbi = EXT4_SB(sb);
2081         char *usr_qf_name, *grp_qf_name;
2082 
2083         if (sbi->s_jquota_fmt) {
2084                 char *fmtname = "";
2085 
2086                 switch (sbi->s_jquota_fmt) {
2087                 case QFMT_VFS_OLD:
2088                         fmtname = "vfsold";
2089                         break;
2090                 case QFMT_VFS_V0:
2091                         fmtname = "vfsv0";
2092                         break;
2093                 case QFMT_VFS_V1:
2094                         fmtname = "vfsv1";
2095                         break;
2096                 }
2097                 seq_printf(seq, ",jqfmt=%s", fmtname);
2098         }
2099 
2100         rcu_read_lock();
2101         usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2102         grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2103         if (usr_qf_name)
2104                 seq_show_option(seq, "usrjquota", usr_qf_name);
2105         if (grp_qf_name)
2106                 seq_show_option(seq, "grpjquota", grp_qf_name);
2107         rcu_read_unlock();
2108 #endif
2109 }
2110 
2111 static const char *token2str(int token)
2112 {
2113         const struct match_token *t;
2114 
2115         for (t = tokens; t->token != Opt_err; t++)
2116                 if (t->token == token && !strchr(t->pattern, '='))
2117                         break;
2118         return t->pattern;
2119 }
2120 
2121 /*
2122  * Show an option if
2123  *  - it's set to a non-default value OR
2124  *  - if the per-sb default is different from the global default
2125  */
2126 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2127                               int nodefs)
2128 {
2129         struct ext4_sb_info *sbi = EXT4_SB(sb);
2130         struct ext4_super_block *es = sbi->s_es;
2131         int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2132         const struct mount_opts *m;
2133         char sep = nodefs ? '\n' : ',';
2134 
2135 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2136 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2137 
2138         if (sbi->s_sb_block != 1)
2139                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2140 
2141         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2142                 int want_set = m->flags & MOPT_SET;
2143                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2144                     (m->flags & MOPT_CLEAR_ERR))
2145                         continue;
2146                 if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2147                         continue; /* skip if same as the default */
2148                 if ((want_set &&
2149                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2150                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2151                         continue; /* select Opt_noFoo vs Opt_Foo */
2152                 SEQ_OPTS_PRINT("%s", token2str(m->token));
2153         }
2154 
2155         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2156             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2157                 SEQ_OPTS_PRINT("resuid=%u",
2158                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
2159         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2160             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2161                 SEQ_OPTS_PRINT("resgid=%u",
2162                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
2163         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2164         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2165                 SEQ_OPTS_PUTS("errors=remount-ro");
2166         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2167                 SEQ_OPTS_PUTS("errors=continue");
2168         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2169                 SEQ_OPTS_PUTS("errors=panic");
2170         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2171                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2172         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2173                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2174         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2175                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2176         if (sb->s_flags & SB_I_VERSION)
2177                 SEQ_OPTS_PUTS("i_version");
2178         if (nodefs || sbi->s_stripe)
2179                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2180         if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2181                         (sbi->s_mount_opt ^ def_mount_opt)) {
2182                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2183                         SEQ_OPTS_PUTS("data=journal");
2184                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2185                         SEQ_OPTS_PUTS("data=ordered");
2186                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2187                         SEQ_OPTS_PUTS("data=writeback");
2188         }
2189         if (nodefs ||
2190             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2191                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2192                                sbi->s_inode_readahead_blks);
2193 
2194         if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2195                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2196                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2197         if (nodefs || sbi->s_max_dir_size_kb)
2198                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2199         if (test_opt(sb, DATA_ERR_ABORT))
2200                 SEQ_OPTS_PUTS("data_err=abort");
2201         if (DUMMY_ENCRYPTION_ENABLED(sbi))
2202                 SEQ_OPTS_PUTS("test_dummy_encryption");
2203 
2204         ext4_show_quota_options(seq, sb);
2205         return 0;
2206 }
2207 
2208 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2209 {
2210         return _ext4_show_options(seq, root->d_sb, 0);
2211 }
2212 
2213 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2214 {
2215         struct super_block *sb = seq->private;
2216         int rc;
2217 
2218         seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2219         rc = _ext4_show_options(seq, sb, 1);
2220         seq_puts(seq, "\n");
2221         return rc;
2222 }
2223 
2224 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2225                             int read_only)
2226 {
2227         struct ext4_sb_info *sbi = EXT4_SB(sb);
2228         int err = 0;
2229 
2230         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2231                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2232                          "forcing read-only mode");
2233                 err = -EROFS;
2234         }
2235         if (read_only)
2236                 goto done;
2237         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2238                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2239                          "running e2fsck is recommended");
2240         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2241                 ext4_msg(sb, KERN_WARNING,
2242                          "warning: mounting fs with errors, "
2243                          "running e2fsck is recommended");
2244         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2245                  le16_to_cpu(es->s_mnt_count) >=
2246                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2247                 ext4_msg(sb, KERN_WARNING,
2248                          "warning: maximal mount count reached, "
2249                          "running e2fsck is recommended");
2250         else if (le32_to_cpu(es->s_checkinterval) &&
2251                  (ext4_get_tstamp(es, s_lastcheck) +
2252                   le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2253                 ext4_msg(sb, KERN_WARNING,
2254                          "warning: checktime reached, "
2255                          "running e2fsck is recommended");
2256         if (!sbi->s_journal)
2257                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2258         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2259                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2260         le16_add_cpu(&es->s_mnt_count, 1);
2261         ext4_update_tstamp(es, s_mtime);
2262         if (sbi->s_journal)
2263                 ext4_set_feature_journal_needs_recovery(sb);
2264 
2265         err = ext4_commit_super(sb, 1);
2266 done:
2267         if (test_opt(sb, DEBUG))
2268                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2269                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2270                         sb->s_blocksize,
2271                         sbi->s_groups_count,
2272                         EXT4_BLOCKS_PER_GROUP(sb),
2273                         EXT4_INODES_PER_GROUP(sb),
2274                         sbi->s_mount_opt, sbi->s_mount_opt2);
2275 
2276         cleancache_init_fs(sb);
2277         return err;
2278 }
2279 
2280 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2281 {
2282         struct ext4_sb_info *sbi = EXT4_SB(sb);
2283         struct flex_groups *new_groups;
2284         int size;
2285 
2286         if (!sbi->s_log_groups_per_flex)
2287                 return 0;
2288 
2289         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2290         if (size <= sbi->s_flex_groups_allocated)
2291                 return 0;
2292 
2293         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2294         new_groups = kvzalloc(size, GFP_KERNEL);
2295         if (!new_groups) {
2296                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2297                          size / (int) sizeof(struct flex_groups));
2298                 return -ENOMEM;
2299         }
2300 
2301         if (sbi->s_flex_groups) {
2302                 memcpy(new_groups, sbi->s_flex_groups,
2303                        (sbi->s_flex_groups_allocated *
2304                         sizeof(struct flex_groups)));
2305                 kvfree(sbi->s_flex_groups);
2306         }
2307         sbi->s_flex_groups = new_groups;
2308         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2309         return 0;
2310 }
2311 
2312 static int ext4_fill_flex_info(struct super_block *sb)
2313 {
2314         struct ext4_sb_info *sbi = EXT4_SB(sb);
2315         struct ext4_group_desc *gdp = NULL;
2316         ext4_group_t flex_group;
2317         int i, err;
2318 
2319         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2320         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2321                 sbi->s_log_groups_per_flex = 0;
2322                 return 1;
2323         }
2324 
2325         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2326         if (err)
2327                 goto failed;
2328 
2329         for (i = 0; i < sbi->s_groups_count; i++) {
2330                 gdp = ext4_get_group_desc(sb, i, NULL);
2331 
2332                 flex_group = ext4_flex_group(sbi, i);
2333                 atomic_add(ext4_free_inodes_count(sb, gdp),
2334                            &sbi->s_flex_groups[flex_group].free_inodes);
2335                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2336                              &sbi->s_flex_groups[flex_group].free_clusters);
2337                 atomic_add(ext4_used_dirs_count(sb, gdp),
2338                            &sbi->s_flex_groups[flex_group].used_dirs);
2339         }
2340 
2341         return 1;
2342 failed:
2343         return 0;
2344 }
2345 
2346 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2347                                    struct ext4_group_desc *gdp)
2348 {
2349         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2350         __u16 crc = 0;
2351         __le32 le_group = cpu_to_le32(block_group);
2352         struct ext4_sb_info *sbi = EXT4_SB(sb);
2353 
2354         if (ext4_has_metadata_csum(sbi->s_sb)) {
2355                 /* Use new metadata_csum algorithm */
2356                 __u32 csum32;
2357                 __u16 dummy_csum = 0;
2358 
2359                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2360                                      sizeof(le_group));
2361                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2362                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2363                                      sizeof(dummy_csum));
2364                 offset += sizeof(dummy_csum);
2365                 if (offset < sbi->s_desc_size)
2366                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2367                                              sbi->s_desc_size - offset);
2368 
2369                 crc = csum32 & 0xFFFF;
2370                 goto out;
2371         }
2372 
2373         /* old crc16 code */
2374         if (!ext4_has_feature_gdt_csum(sb))
2375                 return 0;
2376 
2377         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2378         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2379         crc = crc16(crc, (__u8 *)gdp, offset);
2380         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2381         /* for checksum of struct ext4_group_desc do the rest...*/
2382         if (ext4_has_feature_64bit(sb) &&
2383             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2384                 crc = crc16(crc, (__u8 *)gdp + offset,
2385                             le16_to_cpu(sbi->s_es->s_desc_size) -
2386                                 offset);
2387 
2388 out:
2389         return cpu_to_le16(crc);
2390 }
2391 
2392 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2393                                 struct ext4_group_desc *gdp)
2394 {
2395         if (ext4_has_group_desc_csum(sb) &&
2396             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2397                 return 0;
2398 
2399         return 1;
2400 }
2401 
2402 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2403                               struct ext4_group_desc *gdp)
2404 {
2405         if (!ext4_has_group_desc_csum(sb))
2406                 return;
2407         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2408 }
2409 
2410 /* Called at mount-time, super-block is locked */
2411 static int ext4_check_descriptors(struct super_block *sb,
2412                                   ext4_fsblk_t sb_block,
2413                                   ext4_group_t *first_not_zeroed)
2414 {
2415         struct ext4_sb_info *sbi = EXT4_SB(sb);
2416         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2417         ext4_fsblk_t last_block;
2418         ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2419         ext4_fsblk_t block_bitmap;
2420         ext4_fsblk_t inode_bitmap;
2421         ext4_fsblk_t inode_table;
2422         int flexbg_flag = 0;
2423         ext4_group_t i, grp = sbi->s_groups_count;
2424 
2425         if (ext4_has_feature_flex_bg(sb))
2426                 flexbg_flag = 1;
2427 
2428         ext4_debug("Checking group descriptors");
2429 
2430         for (i = 0; i < sbi->s_groups_count; i++) {
2431                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2432 
2433                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2434                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2435                 else
2436                         last_block = first_block +
2437                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2438 
2439                 if ((grp == sbi->s_groups_count) &&
2440                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2441                         grp = i;
2442 
2443                 block_bitmap = ext4_block_bitmap(sb, gdp);
2444                 if (block_bitmap == sb_block) {
2445                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2446                                  "Block bitmap for group %u overlaps "
2447                                  "superblock", i);
2448                         if (!sb_rdonly(sb))
2449                                 return 0;
2450                 }
2451                 if (block_bitmap >= sb_block + 1 &&
2452                     block_bitmap <= last_bg_block) {
2453                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2454                                  "Block bitmap for group %u overlaps "
2455                                  "block group descriptors", i);
2456                         if (!sb_rdonly(sb))
2457                                 return 0;
2458                 }
2459                 if (block_bitmap < first_block || block_bitmap > last_block) {
2460                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2461                                "Block bitmap for group %u not in group "
2462                                "(block %llu)!", i, block_bitmap);
2463                         return 0;
2464                 }
2465                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2466                 if (inode_bitmap == sb_block) {
2467                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2468                                  "Inode bitmap for group %u overlaps "
2469                                  "superblock", i);
2470                         if (!sb_rdonly(sb))
2471                                 return 0;
2472                 }
2473                 if (inode_bitmap >= sb_block + 1 &&
2474                     inode_bitmap <= last_bg_block) {
2475                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2476                                  "Inode bitmap for group %u overlaps "
2477                                  "block group descriptors", i);
2478                         if (!sb_rdonly(sb))
2479                                 return 0;
2480                 }
2481                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2482                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2483                                "Inode bitmap for group %u not in group "
2484                                "(block %llu)!", i, inode_bitmap);
2485                         return 0;
2486                 }
2487                 inode_table = ext4_inode_table(sb, gdp);
2488                 if (inode_table == sb_block) {
2489                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2490                                  "Inode table for group %u overlaps "
2491                                  "superblock", i);
2492                         if (!sb_rdonly(sb))
2493                                 return 0;
2494                 }
2495                 if (inode_table >= sb_block + 1 &&
2496                     inode_table <= last_bg_block) {
2497                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2498                                  "Inode table for group %u overlaps "
2499                                  "block group descriptors", i);
2500                         if (!sb_rdonly(sb))
2501                                 return 0;
2502                 }
2503                 if (inode_table < first_block ||
2504                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2505                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2506                                "Inode table for group %u not in group "
2507                                "(block %llu)!", i, inode_table);
2508                         return 0;
2509                 }
2510                 ext4_lock_group(sb, i);
2511                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2512                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2513                                  "Checksum for group %u failed (%u!=%u)",
2514                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2515                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2516                         if (!sb_rdonly(sb)) {
2517                                 ext4_unlock_group(sb, i);
2518                                 return 0;
2519                         }
2520                 }
2521                 ext4_unlock_group(sb, i);
2522                 if (!flexbg_flag)
2523                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2524         }
2525         if (NULL != first_not_zeroed)
2526                 *first_not_zeroed = grp;
2527         return 1;
2528 }
2529 
2530 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2531  * the superblock) which were deleted from all directories, but held open by
2532  * a process at the time of a crash.  We walk the list and try to delete these
2533  * inodes at recovery time (only with a read-write filesystem).
2534  *
2535  * In order to keep the orphan inode chain consistent during traversal (in
2536  * case of crash during recovery), we link each inode into the superblock
2537  * orphan list_head and handle it the same way as an inode deletion during
2538  * normal operation (which journals the operations for us).
2539  *
2540  * We only do an iget() and an iput() on each inode, which is very safe if we
2541  * accidentally point at an in-use or already deleted inode.  The worst that
2542  * can happen in this case is that we get a "bit already cleared" message from
2543  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2544  * e2fsck was run on this filesystem, and it must have already done the orphan
2545  * inode cleanup for us, so we can safely abort without any further action.
2546  */
2547 static void ext4_orphan_cleanup(struct super_block *sb,
2548                                 struct ext4_super_block *es)
2549 {
2550         unsigned int s_flags = sb->s_flags;
2551         int ret, nr_orphans = 0, nr_truncates = 0;
2552 #ifdef CONFIG_QUOTA
2553         int quota_update = 0;
2554         int i;
2555 #endif
2556         if (!es->s_last_orphan) {
2557                 jbd_debug(4, "no orphan inodes to clean up\n");
2558                 return;
2559         }
2560 
2561         if (bdev_read_only(sb->s_bdev)) {
2562                 ext4_msg(sb, KERN_ERR, "write access "
2563                         "unavailable, skipping orphan cleanup");
2564                 return;
2565         }
2566 
2567         /* Check if feature set would not allow a r/w mount */
2568         if (!ext4_feature_set_ok(sb, 0)) {
2569                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2570                          "unknown ROCOMPAT features");
2571                 return;
2572         }
2573 
2574         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2575                 /* don't clear list on RO mount w/ errors */
2576                 if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2577                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2578                                   "clearing orphan list.\n");
2579                         es->s_last_orphan = 0;
2580                 }
2581                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2582                 return;
2583         }
2584 
2585         if (s_flags & SB_RDONLY) {
2586                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2587                 sb->s_flags &= ~SB_RDONLY;
2588         }
2589 #ifdef CONFIG_QUOTA
2590         /* Needed for iput() to work correctly and not trash data */
2591         sb->s_flags |= SB_ACTIVE;
2592 
2593         /*
2594          * Turn on quotas which were not enabled for read-only mounts if
2595          * filesystem has quota feature, so that they are updated correctly.
2596          */
2597         if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2598                 int ret = ext4_enable_quotas(sb);
2599 
2600                 if (!ret)
2601                         quota_update = 1;
2602                 else
2603                         ext4_msg(sb, KERN_ERR,
2604                                 "Cannot turn on quotas: error %d", ret);
2605         }
2606 
2607         /* Turn on journaled quotas used for old sytle */
2608         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2609                 if (EXT4_SB(sb)->s_qf_names[i]) {
2610                         int ret = ext4_quota_on_mount(sb, i);
2611 
2612                         if (!ret)
2613                                 quota_update = 1;
2614                         else
2615                                 ext4_msg(sb, KERN_ERR,
2616                                         "Cannot turn on journaled "
2617                                         "quota: type %d: error %d", i, ret);
2618                 }
2619         }
2620 #endif
2621 
2622         while (es->s_last_orphan) {
2623                 struct inode *inode;
2624 
2625                 /*
2626                  * We may have encountered an error during cleanup; if
2627                  * so, skip the rest.
2628                  */
2629                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2630                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2631                         es->s_last_orphan = 0;
2632                         break;
2633                 }
2634 
2635                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2636                 if (IS_ERR(inode)) {
2637                         es->s_last_orphan = 0;
2638                         break;
2639                 }
2640 
2641                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2642                 dquot_initialize(inode);
2643                 if (inode->i_nlink) {
2644                         if (test_opt(sb, DEBUG))
2645                                 ext4_msg(sb, KERN_DEBUG,
2646                                         "%s: truncating inode %lu to %lld bytes",
2647                                         __func__, inode->i_ino, inode->i_size);
2648                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2649                                   inode->i_ino, inode->i_size);
2650                         inode_lock(inode);
2651                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2652                         ret = ext4_truncate(inode);
2653                         if (ret)
2654                                 ext4_std_error(inode->i_sb, ret);
2655                         inode_unlock(inode);
2656                         nr_truncates++;
2657                 } else {
2658                         if (test_opt(sb, DEBUG))
2659                                 ext4_msg(sb, KERN_DEBUG,
2660                                         "%s: deleting unreferenced inode %lu",
2661                                         __func__, inode->i_ino);
2662                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2663                                   inode->i_ino);
2664                         nr_orphans++;
2665                 }
2666                 iput(inode);  /* The delete magic happens here! */
2667         }
2668 
2669 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2670 
2671         if (nr_orphans)
2672                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2673                        PLURAL(nr_orphans));
2674         if (nr_truncates)
2675                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2676                        PLURAL(nr_truncates));
2677 #ifdef CONFIG_QUOTA
2678         /* Turn off quotas if they were enabled for orphan cleanup */
2679         if (quota_update) {
2680                 for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2681                         if (sb_dqopt(sb)->files[i])
2682                                 dquot_quota_off(sb, i);
2683                 }
2684         }
2685 #endif
2686         sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2687 }
2688 
2689 /*
2690  * Maximal extent format file size.
2691  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2692  * extent format containers, within a sector_t, and within i_blocks
2693  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2694  * so that won't be a limiting factor.
2695  *
2696  * However there is other limiting factor. We do store extents in the form
2697  * of starting block and length, hence the resulting length of the extent
2698  * covering maximum file size must fit into on-disk format containers as
2699  * well. Given that length is always by 1 unit bigger than max unit (because
2700  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2701  *
2702  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2703  */
2704 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2705 {
2706         loff_t res;
2707         loff_t upper_limit = MAX_LFS_FILESIZE;
2708 
2709         /* small i_blocks in vfs inode? */
2710         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2711                 /*
2712                  * CONFIG_LBDAF is not enabled implies the inode
2713                  * i_block represent total blocks in 512 bytes
2714                  * 32 == size of vfs inode i_blocks * 8
2715                  */
2716                 upper_limit = (1LL << 32) - 1;
2717 
2718                 /* total blocks in file system block size */
2719                 upper_limit >>= (blkbits - 9);
2720                 upper_limit <<= blkbits;
2721         }
2722 
2723         /*
2724          * 32-bit extent-start container, ee_block. We lower the maxbytes
2725          * by one fs block, so ee_len can cover the extent of maximum file
2726          * size
2727          */
2728         res = (1LL << 32) - 1;
2729         res <<= blkbits;
2730 
2731         /* Sanity check against vm- & vfs- imposed limits */
2732         if (res > upper_limit)
2733                 res = upper_limit;
2734 
2735         return res;
2736 }
2737 
2738 /*
2739  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2740  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2741  * We need to be 1 filesystem block less than the 2^48 sector limit.
2742  */
2743 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2744 {
2745         loff_t res = EXT4_NDIR_BLOCKS;
2746         int meta_blocks;
2747         loff_t upper_limit;
2748         /* This is calculated to be the largest file size for a dense, block
2749          * mapped file such that the file's total number of 512-byte sectors,
2750          * including data and all indirect blocks, does not exceed (2^48 - 1).
2751          *
2752          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2753          * number of 512-byte sectors of the file.
2754          */
2755 
2756         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2757                 /*
2758                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2759                  * the inode i_block field represents total file blocks in
2760                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2761                  */
2762                 upper_limit = (1LL << 32) - 1;
2763 
2764                 /* total blocks in file system block size */
2765                 upper_limit >>= (bits - 9);
2766 
2767         } else {
2768                 /*
2769                  * We use 48 bit ext4_inode i_blocks
2770                  * With EXT4_HUGE_FILE_FL set the i_blocks
2771                  * represent total number of blocks in
2772                  * file system block size
2773                  */
2774                 upper_limit = (1LL << 48) - 1;
2775 
2776         }
2777 
2778         /* indirect blocks */
2779         meta_blocks = 1;
2780         /* double indirect blocks */
2781         meta_blocks += 1 + (1LL << (bits-2));
2782         /* tripple indirect blocks */
2783         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2784 
2785         upper_limit -= meta_blocks;
2786         upper_limit <<= bits;
2787 
2788         res += 1LL << (bits-2);
2789         res += 1LL << (2*(bits-2));
2790         res += 1LL << (3*(bits-2));
2791         res <<= bits;
2792         if (res > upper_limit)
2793                 res = upper_limit;
2794 
2795         if (res > MAX_LFS_FILESIZE)
2796                 res = MAX_LFS_FILESIZE;
2797 
2798         return res;
2799 }
2800 
2801 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2802                                    ext4_fsblk_t logical_sb_block, int nr)
2803 {
2804         struct ext4_sb_info *sbi = EXT4_SB(sb);
2805         ext4_group_t bg, first_meta_bg;
2806         int has_super = 0;
2807 
2808         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2809 
2810         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2811                 return logical_sb_block + nr + 1;
2812         bg = sbi->s_desc_per_block * nr;
2813         if (ext4_bg_has_super(sb, bg))
2814                 has_super = 1;
2815 
2816         /*
2817          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2818          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2819          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2820          * compensate.
2821          */
2822         if (sb->s_blocksize == 1024 && nr == 0 &&
2823             le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2824                 has_super++;
2825 
2826         return (has_super + ext4_group_first_block_no(sb, bg));
2827 }
2828 
2829 /**
2830  * ext4_get_stripe_size: Get the stripe size.
2831  * @sbi: In memory super block info
2832  *
2833  * If we have specified it via mount option, then
2834  * use the mount option value. If the value specified at mount time is
2835  * greater than the blocks per group use the super block value.
2836  * If the super block value is greater than blocks per group return 0.
2837  * Allocator needs it be less than blocks per group.
2838  *
2839  */
2840 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2841 {
2842         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2843         unsigned long stripe_width =
2844                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2845         int ret;
2846 
2847         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2848                 ret = sbi->s_stripe;
2849         else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2850                 ret = stripe_width;
2851         else if (stride && stride <= sbi->s_blocks_per_group)
2852                 ret = stride;
2853         else
2854                 ret = 0;
2855 
2856         /*
2857          * If the stripe width is 1, this makes no sense and
2858          * we set it to 0 to turn off stripe handling code.
2859          */
2860         if (ret <= 1)
2861                 ret = 0;
2862 
2863         return ret;
2864 }
2865 
2866 /*
2867  * Check whether this filesystem can be mounted based on
2868  * the features present and the RDONLY/RDWR mount requested.
2869  * Returns 1 if this filesystem can be mounted as requested,
2870  * 0 if it cannot be.
2871  */
2872 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2873 {
2874         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2875                 ext4_msg(sb, KERN_ERR,
2876                         "Couldn't mount because of "
2877                         "unsupported optional features (%x)",
2878                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2879                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2880                 return 0;
2881         }
2882 
2883         if (readonly)
2884                 return 1;
2885 
2886         if (ext4_has_feature_readonly(sb)) {
2887                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2888                 sb->s_flags |= SB_RDONLY;
2889                 return 1;
2890         }
2891 
2892         /* Check that feature set is OK for a read-write mount */
2893         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2894                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2895                          "unsupported optional features (%x)",
2896                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2897                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2898                 return 0;
2899         }
2900         /*
2901          * Large file size enabled file system can only be mounted
2902          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2903          */
2904         if (ext4_has_feature_huge_file(sb)) {
2905                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2906                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2907                                  "cannot be mounted RDWR without "
2908                                  "CONFIG_LBDAF");
2909                         return 0;
2910                 }
2911         }
2912         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2913                 ext4_msg(sb, KERN_ERR,
2914                          "Can't support bigalloc feature without "
2915                          "extents feature\n");
2916                 return 0;
2917         }
2918 
2919 #ifndef CONFIG_QUOTA
2920         if (ext4_has_feature_quota(sb) && !readonly) {
2921                 ext4_msg(sb, KERN_ERR,
2922                          "Filesystem with quota feature cannot be mounted RDWR "
2923                          "without CONFIG_QUOTA");
2924                 return 0;
2925         }
2926         if (ext4_has_feature_project(sb) && !readonly) {
2927                 ext4_msg(sb, KERN_ERR,
2928                          "Filesystem with project quota feature cannot be mounted RDWR "
2929                          "without CONFIG_QUOTA");
2930                 return 0;
2931         }
2932 #endif  /* CONFIG_QUOTA */
2933         return 1;
2934 }
2935 
2936 /*
2937  * This function is called once a day if we have errors logged
2938  * on the file system
2939  */
2940 static void print_daily_error_info(struct timer_list *t)
2941 {
2942         struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2943         struct super_block *sb = sbi->s_sb;
2944         struct ext4_super_block *es = sbi->s_es;
2945 
2946         if (es->s_error_count)
2947                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2948                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2949                          le32_to_cpu(es->s_error_count));
2950         if (es->s_first_error_time) {
2951                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
2952                        sb->s_id,
2953                        ext4_get_tstamp(es, s_first_error_time),
2954                        (int) sizeof(es->s_first_error_func),
2955                        es->s_first_error_func,
2956                        le32_to_cpu(es->s_first_error_line));
2957                 if (es->s_first_error_ino)
2958                         printk(KERN_CONT ": inode %u",
2959                                le32_to_cpu(es->s_first_error_ino));
2960                 if (es->s_first_error_block)
2961                         printk(KERN_CONT ": block %llu", (unsigned long long)
2962                                le64_to_cpu(es->s_first_error_block));
2963                 printk(KERN_CONT "\n");
2964         }
2965         if (es->s_last_error_time) {
2966                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
2967                        sb->s_id,
2968                        ext4_get_tstamp(es, s_last_error_time),
2969                        (int) sizeof(es->s_last_error_func),
2970                        es->s_last_error_func,
2971                        le32_to_cpu(es->s_last_error_line));
2972                 if (es->s_last_error_ino)
2973                         printk(KERN_CONT ": inode %u",
2974                                le32_to_cpu(es->s_last_error_ino));
2975                 if (es->s_last_error_block)
2976                         printk(KERN_CONT ": block %llu", (unsigned long long)
2977                                le64_to_cpu(es->s_last_error_block));
2978                 printk(KERN_CONT "\n");
2979         }
2980         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2981 }
2982 
2983 /* Find next suitable group and run ext4_init_inode_table */
2984 static int ext4_run_li_request(struct ext4_li_request *elr)
2985 {
2986         struct ext4_group_desc *gdp = NULL;
2987         ext4_group_t group, ngroups;
2988         struct super_block *sb;
2989         unsigned long timeout = 0;
2990         int ret = 0;
2991 
2992         sb = elr->lr_super;
2993         ngroups = EXT4_SB(sb)->s_groups_count;
2994 
2995         for (group = elr->lr_next_group; group < ngroups; group++) {
2996                 gdp = ext4_get_group_desc(sb, group, NULL);
2997                 if (!gdp) {
2998                         ret = 1;
2999                         break;
3000                 }
3001 
3002                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3003                         break;
3004         }
3005 
3006         if (group >= ngroups)
3007                 ret = 1;
3008 
3009         if (!ret) {
3010                 timeout = jiffies;
3011                 ret = ext4_init_inode_table(sb, group,
3012                                             elr->lr_timeout ? 0 : 1);
3013                 if (elr->lr_timeout == 0) {
3014                         timeout = (jiffies - timeout) *
3015                                   elr->lr_sbi->s_li_wait_mult;
3016                         elr->lr_timeout = timeout;
3017                 }
3018                 elr->lr_next_sched = jiffies + elr->lr_timeout;
3019                 elr->lr_next_group = group + 1;
3020         }
3021         return ret;
3022 }
3023 
3024 /*
3025  * Remove lr_request from the list_request and free the
3026  * request structure. Should be called with li_list_mtx held
3027  */
3028 static void ext4_remove_li_request(struct ext4_li_request *elr)
3029 {
3030         struct ext4_sb_info *sbi;
3031 
3032         if (!elr)
3033                 return;
3034 
3035         sbi = elr->lr_sbi;
3036 
3037         list_del(&elr->lr_request);
3038         sbi->s_li_request = NULL;
3039         kfree(elr);
3040 }
3041 
3042 static void ext4_unregister_li_request(struct super_block *sb)
3043 {
3044         mutex_lock(&ext4_li_mtx);
3045         if (!ext4_li_info) {
3046                 mutex_unlock(&ext4_li_mtx);
3047                 return;
3048         }
3049 
3050         mutex_lock(&ext4_li_info->li_list_mtx);
3051         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3052         mutex_unlock(&ext4_li_info->li_list_mtx);
3053         mutex_unlock(&ext4_li_mtx);
3054 }
3055 
3056 static struct task_struct *ext4_lazyinit_task;
3057 
3058 /*
3059  * This is the function where ext4lazyinit thread lives. It walks
3060  * through the request list searching for next scheduled filesystem.
3061  * When such a fs is found, run the lazy initialization request
3062  * (ext4_rn_li_request) and keep track of the time spend in this
3063  * function. Based on that time we compute next schedule time of
3064  * the request. When walking through the list is complete, compute
3065  * next waking time and put itself into sleep.
3066  */
3067 static int ext4_lazyinit_thread(void *arg)
3068 {
3069         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3070         struct list_head *pos, *n;
3071         struct ext4_li_request *elr;
3072         unsigned long next_wakeup, cur;
3073 
3074         BUG_ON(NULL == eli);
3075 
3076 cont_thread:
3077         while (true) {
3078                 next_wakeup = MAX_JIFFY_OFFSET;
3079 
3080                 mutex_lock(&eli->li_list_mtx);
3081                 if (list_empty(&eli->li_request_list)) {
3082                         mutex_unlock(&eli->li_list_mtx);
3083                         goto exit_thread;
3084                 }
3085                 list_for_each_safe(pos, n, &eli->li_request_list) {
3086                         int err = 0;
3087                         int progress = 0;
3088                         elr = list_entry(pos, struct ext4_li_request,
3089                                          lr_request);
3090 
3091                         if (time_before(jiffies, elr->lr_next_sched)) {
3092                                 if (time_before(elr->lr_next_sched, next_wakeup))
3093                                         next_wakeup = elr->lr_next_sched;
3094                                 continue;
3095                         }
3096                         if (down_read_trylock(&elr->lr_super->s_umount)) {
3097                                 if (sb_start_write_trylock(elr->lr_super)) {
3098                                         progress = 1;
3099                                         /*
3100                                          * We hold sb->s_umount, sb can not
3101                                          * be removed from the list, it is
3102                                          * now safe to drop li_list_mtx
3103                                          */
3104                                         mutex_unlock(&eli->li_list_mtx);
3105                                         err = ext4_run_li_request(elr);
3106                                         sb_end_write(elr->lr_super);
3107                                         mutex_lock(&eli->li_list_mtx);
3108                                         n = pos->next;
3109                                 }
3110                                 up_read((&elr->lr_super->s_umount));
3111                         }
3112                         /* error, remove the lazy_init job */
3113                         if (err) {
3114                                 ext4_remove_li_request(elr);
3115                                 continue;
3116                         }
3117                         if (!progress) {
3118                                 elr->lr_next_sched = jiffies +
3119                                         (prandom_u32()
3120                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3121                         }
3122                         if (time_before(elr->lr_next_sched, next_wakeup))
3123                                 next_wakeup = elr->lr_next_sched;
3124                 }
3125                 mutex_unlock(&eli->li_list_mtx);
3126 
3127                 try_to_freeze();
3128 
3129                 cur = jiffies;
3130                 if ((time_after_eq(cur, next_wakeup)) ||
3131                     (MAX_JIFFY_OFFSET == next_wakeup)) {
3132                         cond_resched();
3133                         continue;
3134                 }
3135 
3136                 schedule_timeout_interruptible(next_wakeup - cur);
3137 
3138                 if (kthread_should_stop()) {
3139                         ext4_clear_request_list();
3140                         goto exit_thread;
3141                 }
3142         }
3143 
3144 exit_thread:
3145         /*
3146          * It looks like the request list is empty, but we need
3147          * to check it under the li_list_mtx lock, to prevent any
3148          * additions into it, and of course we should lock ext4_li_mtx
3149          * to atomically free the list and ext4_li_info, because at
3150          * this point another ext4 filesystem could be registering
3151          * new one.
3152          */
3153         mutex_lock(&ext4_li_mtx);
3154         mutex_lock(&eli->li_list_mtx);
3155         if (!list_empty(&eli->li_request_list)) {
3156                 mutex_unlock(&eli->li_list_mtx);
3157                 mutex_unlock(&ext4_li_mtx);
3158                 goto cont_thread;
3159         }
3160         mutex_unlock(&eli->li_list_mtx);
3161         kfree(ext4_li_info);
3162         ext4_li_info = NULL;
3163         mutex_unlock(&ext4_li_mtx);
3164 
3165         return 0;
3166 }
3167 
3168 static void ext4_clear_request_list(void)
3169 {
3170         struct list_head *pos, *n;
3171         struct ext4_li_request *elr;
3172 
3173         mutex_lock(&ext4_li_info->li_list_mtx);
3174         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3175                 elr = list_entry(pos, struct ext4_li_request,
3176                                  lr_request);
3177                 ext4_remove_li_request(elr);
3178         }
3179         mutex_unlock(&ext4_li_info->li_list_mtx);
3180 }
3181 
3182 static int ext4_run_lazyinit_thread(void)
3183 {
3184         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3185                                          ext4_li_info, "ext4lazyinit");
3186         if (IS_ERR(ext4_lazyinit_task)) {
3187                 int err = PTR_ERR(ext4_lazyinit_task);
3188                 ext4_clear_request_list();
3189                 kfree(ext4_li_info);
3190                 ext4_li_info = NULL;
3191                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3192                                  "initialization thread\n",
3193                                  err);
3194                 return err;
3195         }
3196         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3197         return 0;
3198 }
3199 
3200 /*
3201  * Check whether it make sense to run itable init. thread or not.
3202  * If there is at least one uninitialized inode table, return
3203  * corresponding group number, else the loop goes through all
3204  * groups and return total number of groups.
3205  */
3206 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3207 {
3208         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3209         struct ext4_group_desc *gdp = NULL;
3210 
3211         if (!ext4_has_group_desc_csum(sb))
3212                 return ngroups;
3213 
3214         for (group = 0; group < ngroups; group++) {
3215                 gdp = ext4_get_group_desc(sb, group, NULL);
3216                 if (!gdp)
3217                         continue;
3218 
3219                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3220                         break;
3221         }
3222 
3223         return group;
3224 }
3225 
3226 static int ext4_li_info_new(void)
3227 {
3228         struct ext4_lazy_init *eli = NULL;
3229 
3230         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3231         if (!eli)
3232                 return -ENOMEM;
3233 
3234         INIT_LIST_HEAD(&eli->li_request_list);
3235         mutex_init(&eli->li_list_mtx);
3236 
3237         eli->li_state |= EXT4_LAZYINIT_QUIT;
3238 
3239         ext4_li_info = eli;
3240 
3241         return 0;
3242 }
3243 
3244 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3245                                             ext4_group_t start)
3246 {
3247         struct ext4_sb_info *sbi = EXT4_SB(sb);
3248         struct ext4_li_request *elr;
3249 
3250         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3251         if (!elr)
3252                 return NULL;
3253 
3254         elr->lr_super = sb;
3255         elr->lr_sbi = sbi;
3256         elr->lr_next_group = start;
3257 
3258         /*
3259          * Randomize first schedule time of the request to
3260          * spread the inode table initialization requests
3261          * better.
3262          */
3263         elr->lr_next_sched = jiffies + (prandom_u32() %
3264                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3265         return elr;
3266 }
3267 
3268 int ext4_register_li_request(struct super_block *sb,
3269                              ext4_group_t first_not_zeroed)
3270 {
3271         struct ext4_sb_info *sbi = EXT4_SB(sb);
3272         struct ext4_li_request *elr = NULL;
3273         ext4_group_t ngroups = sbi->s_groups_count;
3274         int ret = 0;
3275 
3276         mutex_lock(&ext4_li_mtx);
3277         if (sbi->s_li_request != NULL) {
3278                 /*
3279                  * Reset timeout so it can be computed again, because
3280                  * s_li_wait_mult might have changed.
3281                  */
3282                 sbi->s_li_request->lr_timeout = 0;
3283                 goto out;
3284         }
3285 
3286         if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3287             !test_opt(sb, INIT_INODE_TABLE))
3288                 goto out;
3289 
3290         elr = ext4_li_request_new(sb, first_not_zeroed);
3291         if (!elr) {
3292                 ret = -ENOMEM;
3293                 goto out;
3294         }
3295 
3296         if (NULL == ext4_li_info) {
3297                 ret = ext4_li_info_new();
3298                 if (ret)
3299                         goto out;
3300         }
3301 
3302         mutex_lock(&ext4_li_info->li_list_mtx);
3303         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3304         mutex_unlock(&ext4_li_info->li_list_mtx);
3305 
3306         sbi->s_li_request = elr;
3307         /*
3308          * set elr to NULL here since it has been inserted to
3309          * the request_list and the removal and free of it is
3310          * handled by ext4_clear_request_list from now on.
3311          */
3312         elr = NULL;
3313 
3314         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3315                 ret = ext4_run_lazyinit_thread();
3316                 if (ret)
3317                         goto out;
3318         }
3319 out:
3320         mutex_unlock(&ext4_li_mtx);
3321         if (ret)
3322                 kfree(elr);
3323         return ret;
3324 }
3325 
3326 /*
3327  * We do not need to lock anything since this is called on
3328  * module unload.
3329  */
3330 static void ext4_destroy_lazyinit_thread(void)
3331 {
3332         /*
3333          * If thread exited earlier
3334          * there's nothing to be done.
3335          */
3336         if (!ext4_li_info || !ext4_lazyinit_task)
3337                 return;
3338 
3339         kthread_stop(ext4_lazyinit_task);
3340 }
3341 
3342 static int set_journal_csum_feature_set(struct super_block *sb)
3343 {
3344         int ret = 1;
3345         int compat, incompat;
3346         struct ext4_sb_info *sbi = EXT4_SB(sb);
3347 
3348         if (ext4_has_metadata_csum(sb)) {
3349                 /* journal checksum v3 */
3350                 compat = 0;
3351                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3352         } else {
3353                 /* journal checksum v1 */
3354                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3355                 incompat = 0;
3356         }
3357 
3358         jbd2_journal_clear_features(sbi->s_journal,
3359                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3360                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3361                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3362         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3363                 ret = jbd2_journal_set_features(sbi->s_journal,
3364                                 compat, 0,
3365                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3366                                 incompat);
3367         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3368                 ret = jbd2_journal_set_features(sbi->s_journal,
3369                                 compat, 0,
3370                                 incompat);
3371                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3372                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3373         } else {
3374                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3375                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3376         }
3377 
3378         return ret;
3379 }
3380 
3381 /*
3382  * Note: calculating the overhead so we can be compatible with
3383  * historical BSD practice is quite difficult in the face of
3384  * clusters/bigalloc.  This is because multiple metadata blocks from
3385  * different block group can end up in the same allocation cluster.
3386  * Calculating the exact overhead in the face of clustered allocation
3387  * requires either O(all block bitmaps) in memory or O(number of block
3388  * groups**2) in time.  We will still calculate the superblock for
3389  * older file systems --- and if we come across with a bigalloc file
3390  * system with zero in s_overhead_clusters the estimate will be close to
3391  * correct especially for very large cluster sizes --- but for newer
3392  * file systems, it's better to calculate this figure once at mkfs
3393  * time, and store it in the superblock.  If the superblock value is
3394  * present (even for non-bigalloc file systems), we will use it.
3395  */
3396 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3397                           char *buf)
3398 {
3399         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3400         struct ext4_group_desc  *gdp;
3401         ext4_fsblk_t            first_block, last_block, b;
3402         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3403         int                     s, j, count = 0;
3404 
3405         if (!ext4_has_feature_bigalloc(sb))
3406                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3407                         sbi->s_itb_per_group + 2);
3408 
3409         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3410                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3411         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3412         for (i = 0; i < ngroups; i++) {
3413                 gdp = ext4_get_group_desc(sb, i, NULL);
3414                 b = ext4_block_bitmap(sb, gdp);
3415                 if (b >= first_block && b <= last_block) {
3416                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3417                         count++;
3418                 }
3419                 b = ext4_inode_bitmap(sb, gdp);
3420                 if (b >= first_block && b <= last_block) {
3421                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3422                         count++;
3423                 }
3424                 b = ext4_inode_table(sb, gdp);
3425                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3426                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3427                                 int c = EXT4_B2C(sbi, b - first_block);
3428                                 ext4_set_bit(c, buf);
3429                                 count++;
3430                         }
3431                 if (i != grp)
3432                         continue;
3433                 s = 0;
3434                 if (ext4_bg_has_super(sb, grp)) {
3435                         ext4_set_bit(s++, buf);
3436                         count++;
3437                 }
3438                 j = ext4_bg_num_gdb(sb, grp);
3439                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3440                         ext4_error(sb, "Invalid number of block group "
3441                                    "descriptor blocks: %d", j);
3442                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3443                 }
3444                 count += j;
3445                 for (; j > 0; j--)
3446                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3447         }
3448         if (!count)
3449                 return 0;
3450         return EXT4_CLUSTERS_PER_GROUP(sb) -
3451                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3452 }
3453 
3454 /*
3455  * Compute the overhead and stash it in sbi->s_overhead
3456  */
3457 int ext4_calculate_overhead(struct super_block *sb)
3458 {
3459         struct ext4_sb_info *sbi = EXT4_SB(sb);
3460         struct ext4_super_block *es = sbi->s_es;
3461         struct inode *j_inode;
3462         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3463         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3464         ext4_fsblk_t overhead = 0;
3465         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3466 
3467         if (!buf)
3468                 return -ENOMEM;
3469 
3470         /*
3471          * Compute the overhead (FS structures).  This is constant
3472          * for a given filesystem unless the number of block groups
3473          * changes so we cache the previous value until it does.
3474          */
3475 
3476         /*
3477          * All of the blocks before first_data_block are overhead
3478          */
3479         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3480 
3481         /*
3482          * Add the overhead found in each block group
3483          */
3484         for (i = 0; i < ngroups; i++) {
3485                 int blks;
3486 
3487                 blks = count_overhead(sb, i, buf);
3488                 overhead += blks;
3489                 if (blks)
3490                         memset(buf, 0, PAGE_SIZE);
3491                 cond_resched();
3492         }
3493 
3494         /*
3495          * Add the internal journal blocks whether the journal has been
3496          * loaded or not
3497          */
3498         if (sbi->s_journal && !sbi->journal_bdev)
3499                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3500         else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3501                 j_inode = ext4_get_journal_inode(sb, j_inum);
3502                 if (j_inode) {
3503                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3504                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
3505                         iput(j_inode);
3506                 } else {
3507                         ext4_msg(sb, KERN_ERR, "can't get journal size");
3508                 }
3509         }
3510         sbi->s_overhead = overhead;
3511         smp_wmb();
3512         free_page((unsigned long) buf);
3513         return 0;
3514 }
3515 
3516 static void ext4_clamp_want_extra_isize(struct super_block *sb)
3517 {
3518         struct ext4_sb_info *sbi = EXT4_SB(sb);
3519         struct ext4_super_block *es = sbi->s_es;
3520 
3521         /* determine the minimum size of new large inodes, if present */
3522         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
3523             sbi->s_want_extra_isize == 0) {
3524                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3525                                                      EXT4_GOOD_OLD_INODE_SIZE;
3526                 if (ext4_has_feature_extra_isize(sb)) {
3527                         if (sbi->s_want_extra_isize <
3528                             le16_to_cpu(es->s_want_extra_isize))
3529                                 sbi->s_want_extra_isize =
3530                                         le16_to_cpu(es->s_want_extra_isize);
3531                         if (sbi->s_want_extra_isize <
3532                             le16_to_cpu(es->s_min_extra_isize))
3533                                 sbi->s_want_extra_isize =
3534                                         le16_to_cpu(es->s_min_extra_isize);
3535                 }
3536         }
3537         /* Check if enough inode space is available */
3538         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3539                                                         sbi->s_inode_size) {
3540                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3541                                                        EXT4_GOOD_OLD_INODE_SIZE;
3542                 ext4_msg(sb, KERN_INFO,
3543                          "required extra inode space not available");
3544         }
3545 }
3546 
3547 static void ext4_set_resv_clusters(struct super_block *sb)
3548 {
3549         ext4_fsblk_t resv_clusters;
3550         struct ext4_sb_info *sbi = EXT4_SB(sb);
3551 
3552         /*
3553          * There's no need to reserve anything when we aren't using extents.
3554          * The space estimates are exact, there are no unwritten extents,
3555          * hole punching doesn't need new metadata... This is needed especially
3556          * to keep ext2/3 backward compatibility.
3557          */
3558         if (!ext4_has_feature_extents(sb))
3559                 return;
3560         /*
3561          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3562          * This should cover the situations where we can not afford to run
3563          * out of space like for example punch hole, or converting
3564          * unwritten extents in delalloc path. In most cases such
3565          * allocation would require 1, or 2 blocks, higher numbers are
3566          * very rare.
3567          */
3568         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3569                          sbi->s_cluster_bits);
3570 
3571         do_div(resv_clusters, 50);
3572         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3573 
3574         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3575 }
3576 
3577 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3578 {
3579         struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3580         char *orig_data = kstrdup(data, GFP_KERNEL);
3581         struct buffer_head *bh;
3582         struct ext4_super_block *es = NULL;
3583         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3584         ext4_fsblk_t block;
3585         ext4_fsblk_t sb_block = get_sb_block(&data);
3586         ext4_fsblk_t logical_sb_block;
3587         unsigned long offset = 0;
3588         unsigned long journal_devnum = 0;
3589         unsigned long def_mount_opts;
3590         struct inode *root;
3591         const char *descr;
3592         int ret = -ENOMEM;
3593         int blocksize, clustersize;
3594         unsigned int db_count;
3595         unsigned int i;
3596         int needs_recovery, has_huge_files, has_bigalloc;
3597         __u64 blocks_count;
3598         int err = 0;
3599         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3600         ext4_group_t first_not_zeroed;
3601 
3602         if ((data && !orig_data) || !sbi)
3603                 goto out_free_base;
3604 
3605         sbi->s_daxdev = dax_dev;
3606         sbi->s_blockgroup_lock =
3607                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3608         if (!sbi->s_blockgroup_lock)
3609                 goto out_free_base;
3610 
3611         sb->s_fs_info = sbi;
3612         sbi->s_sb = sb;
3613         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3614         sbi->s_sb_block = sb_block;
3615         if (sb->s_bdev->bd_part)
3616                 sbi->s_sectors_written_start =
3617                         part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3618 
3619         /* Cleanup superblock name */
3620         strreplace(sb->s_id, '/', '!');
3621 
3622         /* -EINVAL is default */
3623         ret = -EINVAL;
3624         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3625         if (!blocksize) {
3626                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3627                 goto out_fail;
3628         }
3629 
3630         /*
3631          * The ext4 superblock will not be buffer aligned for other than 1kB
3632          * block sizes.  We need to calculate the offset from buffer start.
3633          */
3634         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3635                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3636                 offset = do_div(logical_sb_block, blocksize);
3637         } else {
3638                 logical_sb_block = sb_block;
3639         }
3640 
3641         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3642                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3643                 goto out_fail;
3644         }
3645         /*
3646          * Note: s_es must be initialized as soon as possible because
3647          *       some ext4 macro-instructions depend on its value
3648          */
3649         es = (struct ext4_super_block *) (bh->b_data + offset);
3650         sbi->s_es = es;
3651         sb->s_magic = le16_to_cpu(es->s_magic);
3652         if (sb->s_magic != EXT4_SUPER_MAGIC)
3653                 goto cantfind_ext4;
3654         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3655 
3656         /* Warn if metadata_csum and gdt_csum are both set. */
3657         if (ext4_has_feature_metadata_csum(sb) &&
3658             ext4_has_feature_gdt_csum(sb))
3659                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3660                              "redundant flags; please run fsck.");
3661 
3662         /* Check for a known checksum algorithm */
3663         if (!ext4_verify_csum_type(sb, es)) {
3664                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3665                          "unknown checksum algorithm.");
3666                 silent = 1;
3667                 goto cantfind_ext4;
3668         }
3669 
3670         /* Load the checksum driver */
3671         sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3672         if (IS_ERR(sbi->s_chksum_driver)) {
3673                 ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3674                 ret = PTR_ERR(sbi->s_chksum_driver);
3675                 sbi->s_chksum_driver = NULL;
3676                 goto failed_mount;
3677         }
3678 
3679         /* Check superblock checksum */
3680         if (!ext4_superblock_csum_verify(sb, es)) {
3681                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3682                          "invalid superblock checksum.  Run e2fsck?");
3683                 silent = 1;
3684                 ret = -EFSBADCRC;
3685                 goto cantfind_ext4;
3686         }
3687 
3688         /* Precompute checksum seed for all metadata */
3689         if (ext4_has_feature_csum_seed(sb))
3690                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3691         else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3692                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3693                                                sizeof(es->s_uuid));
3694 
3695         /* Set defaults before we parse the mount options */
3696         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3697         set_opt(sb, INIT_INODE_TABLE);
3698         if (def_mount_opts & EXT4_DEFM_DEBUG)
3699                 set_opt(sb, DEBUG);
3700         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3701                 set_opt(sb, GRPID);
3702         if (def_mount_opts & EXT4_DEFM_UID16)
3703                 set_opt(sb, NO_UID32);
3704         /* xattr user namespace & acls are now defaulted on */
3705         set_opt(sb, XATTR_USER);
3706 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3707         set_opt(sb, POSIX_ACL);
3708 #endif
3709         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3710         if (ext4_has_metadata_csum(sb))
3711                 set_opt(sb, JOURNAL_CHECKSUM);
3712 
3713         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3714                 set_opt(sb, JOURNAL_DATA);
3715         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3716                 set_opt(sb, ORDERED_DATA);
3717         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3718                 set_opt(sb, WRITEBACK_DATA);
3719 
3720         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3721                 set_opt(sb, ERRORS_PANIC);
3722         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3723                 set_opt(sb, ERRORS_CONT);
3724         else
3725                 set_opt(sb, ERRORS_RO);
3726         /* block_validity enabled by default; disable with noblock_validity */
3727         set_opt(sb, BLOCK_VALIDITY);
3728         if (def_mount_opts & EXT4_DEFM_DISCARD)
3729                 set_opt(sb, DISCARD);
3730 
3731         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3732         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3733         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3734         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3735         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3736 
3737         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3738                 set_opt(sb, BARRIER);
3739 
3740         /*
3741          * enable delayed allocation by default
3742          * Use -o nodelalloc to turn it off
3743          */
3744         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3745             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3746                 set_opt(sb, DELALLOC);
3747 
3748         /*
3749          * set default s_li_wait_mult for lazyinit, for the case there is
3750          * no mount option specified.
3751          */
3752         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3753 
3754         if (sbi->s_es->s_mount_opts[0]) {
3755                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3756                                               sizeof(sbi->s_es->s_mount_opts),
3757                                               GFP_KERNEL);
3758                 if (!s_mount_opts)
3759                         goto failed_mount;
3760                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3761                                    &journal_ioprio, 0)) {
3762                         ext4_msg(sb, KERN_WARNING,
3763                                  "failed to parse options in superblock: %s",
3764                                  s_mount_opts);
3765                 }
3766                 kfree(s_mount_opts);
3767         }
3768         sbi->s_def_mount_opt = sbi->s_mount_opt;
3769         if (!parse_options((char *) data, sb, &journal_devnum,
3770                            &journal_ioprio, 0))
3771                 goto failed_mount;
3772 
3773         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3774                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3775                             "with data=journal disables delayed "
3776                             "allocation and O_DIRECT support!\n");
3777                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3778                         ext4_msg(sb, KERN_ERR, "can't mount with "
3779                                  "both data=journal and delalloc");
3780                         goto failed_mount;
3781                 }
3782                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3783                         ext4_msg(sb, KERN_ERR, "can't mount with "
3784                                  "both data=journal and dioread_nolock");
3785                         goto failed_mount;
3786                 }
3787                 if (test_opt(sb, DAX)) {
3788                         ext4_msg(sb, KERN_ERR, "can't mount with "
3789                                  "both data=journal and dax");
3790                         goto failed_mount;
3791                 }
3792                 if (ext4_has_feature_encrypt(sb)) {
3793                         ext4_msg(sb, KERN_WARNING,
3794                                  "encrypted files will use data=ordered "
3795                                  "instead of data journaling mode");
3796                 }
3797                 if (test_opt(sb, DELALLOC))
3798                         clear_opt(sb, DELALLOC);
3799         } else {
3800                 sb->s_iflags |= SB_I_CGROUPWB;
3801         }
3802 
3803         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3804                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3805 
3806         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3807             (ext4_has_compat_features(sb) ||
3808              ext4_has_ro_compat_features(sb) ||
3809              ext4_has_incompat_features(sb)))
3810                 ext4_msg(sb, KERN_WARNING,
3811                        "feature flags set on rev 0 fs, "
3812                        "running e2fsck is recommended");
3813 
3814         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3815                 set_opt2(sb, HURD_COMPAT);
3816                 if (ext4_has_feature_64bit(sb)) {
3817                         ext4_msg(sb, KERN_ERR,
3818                                  "The Hurd can't support 64-bit file systems");
3819                         goto failed_mount;
3820                 }
3821 
3822                 /*
3823                  * ea_inode feature uses l_i_version field which is not
3824                  * available in HURD_COMPAT mode.
3825                  */
3826                 if (ext4_has_feature_ea_inode(sb)) {
3827                         ext4_msg(sb, KERN_ERR,
3828                                  "ea_inode feature is not supported for Hurd");
3829                         goto failed_mount;
3830                 }
3831         }
3832 
3833         if (IS_EXT2_SB(sb)) {
3834                 if (ext2_feature_set_ok(sb))
3835                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3836                                  "using the ext4 subsystem");
3837                 else {
3838                         /*
3839                          * If we're probing be silent, if this looks like
3840                          * it's actually an ext[34] filesystem.
3841                          */
3842                         if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3843                                 goto failed_mount;
3844                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3845                                  "to feature incompatibilities");
3846                         goto failed_mount;
3847                 }
3848         }
3849 
3850         if (IS_EXT3_SB(sb)) {
3851                 if (ext3_feature_set_ok(sb))
3852                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3853                                  "using the ext4 subsystem");
3854                 else {
3855                         /*
3856                          * If we're probing be silent, if this looks like
3857                          * it's actually an ext4 filesystem.
3858                          */
3859                         if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3860                                 goto failed_mount;
3861                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3862                                  "to feature incompatibilities");
3863                         goto failed_mount;
3864                 }
3865         }
3866 
3867         /*
3868          * Check feature flags regardless of the revision level, since we
3869          * previously didn't change the revision level when setting the flags,
3870          * so there is a chance incompat flags are set on a rev 0 filesystem.
3871          */
3872         if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3873                 goto failed_mount;
3874 
3875         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3876         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3877             blocksize > EXT4_MAX_BLOCK_SIZE) {
3878                 ext4_msg(sb, KERN_ERR,
3879                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3880                          blocksize, le32_to_cpu(es->s_log_block_size));
3881                 goto failed_mount;
3882         }
3883         if (le32_to_cpu(es->s_log_block_size) >
3884             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3885                 ext4_msg(sb, KERN_ERR,
3886                          "Invalid log block size: %u",
3887                          le32_to_cpu(es->s_log_block_size));
3888                 goto failed_mount;
3889         }
3890         if (le32_to_cpu(es->s_log_cluster_size) >
3891             (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3892                 ext4_msg(sb, KERN_ERR,
3893                          "Invalid log cluster size: %u",
3894                          le32_to_cpu(es->s_log_cluster_size));
3895                 goto failed_mount;
3896         }
3897 
3898         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3899                 ext4_msg(sb, KERN_ERR,
3900                          "Number of reserved GDT blocks insanely large: %d",
3901                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3902                 goto failed_mount;
3903         }
3904 
3905         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3906                 if (ext4_has_feature_inline_data(sb)) {
3907                         ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3908                                         " that may contain inline data");
3909                         goto failed_mount;
3910                 }
3911                 if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
3912                         ext4_msg(sb, KERN_ERR,
3913                                 "DAX unsupported by block device.");
3914                         goto failed_mount;
3915                 }
3916         }
3917 
3918         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3919                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3920                          es->s_encryption_level);
3921                 goto failed_mount;
3922         }
3923 
3924         if (sb->s_blocksize != blocksize) {
3925                 /* Validate the filesystem blocksize */
3926                 if (!sb_set_blocksize(sb, blocksize)) {
3927                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3928                                         blocksize);
3929                         goto failed_mount;
3930                 }
3931 
3932                 brelse(bh);
3933                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3934                 offset = do_div(logical_sb_block, blocksize);
3935                 bh = sb_bread_unmovable(sb, logical_sb_block);
3936                 if (!bh) {
3937                         ext4_msg(sb, KERN_ERR,
3938                                "Can't read superblock on 2nd try");
3939                         goto failed_mount;
3940                 }
3941                 es = (struct ext4_super_block *)(bh->b_data + offset);
3942                 sbi->s_es = es;
3943                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3944                         ext4_msg(sb, KERN_ERR,
3945                                "Magic mismatch, very weird!");
3946                         goto failed_mount;
3947                 }
3948         }
3949 
3950         has_huge_files = ext4_has_feature_huge_file(sb);
3951         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3952                                                       has_huge_files);
3953         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3954 
3955         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3956                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3957                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3958         } else {
3959                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3960                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3961                 if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3962                         ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3963                                  sbi->s_first_ino);
3964                         goto failed_mount;
3965                 }
3966                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3967                     (!is_power_of_2(sbi->s_inode_size)) ||
3968                     (sbi->s_inode_size > blocksize)) {
3969                         ext4_msg(sb, KERN_ERR,
3970                                "unsupported inode size: %d",
3971                                sbi->s_inode_size);
3972                         goto failed_mount;
3973                 }
3974                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3975                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3976         }
3977 
3978         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3979         if (ext4_has_feature_64bit(sb)) {
3980                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3981                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3982                     !is_power_of_2(sbi->s_desc_size)) {
3983                         ext4_msg(sb, KERN_ERR,
3984                                "unsupported descriptor size %lu",
3985                                sbi->s_desc_size);
3986                         goto failed_mount;
3987                 }
3988         } else
3989                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3990 
3991         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3992         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3993 
3994         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3995         if (sbi->s_inodes_per_block == 0)
3996                 goto cantfind_ext4;
3997         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3998             sbi->s_inodes_per_group > blocksize * 8) {
3999                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4000                          sbi->s_blocks_per_group);
4001                 goto failed_mount;
4002         }
4003         sbi->s_itb_per_group = sbi->s_inodes_per_group /
4004                                         sbi->s_inodes_per_block;
4005         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4006         sbi->s_sbh = bh;
4007         sbi->s_mount_state = le16_to_cpu(es->s_state);
4008         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4009         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4010 
4011         for (i = 0; i < 4; i++)
4012                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4013         sbi->s_def_hash_version = es->s_def_hash_version;
4014         if (ext4_has_feature_dir_index(sb)) {
4015                 i = le32_to_cpu(es->s_flags);
4016                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
4017                         sbi->s_hash_unsigned = 3;
4018                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4019 #ifdef __CHAR_UNSIGNED__
4020                         if (!sb_rdonly(sb))
4021                                 es->s_flags |=
4022                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4023                         sbi->s_hash_unsigned = 3;
4024 #else
4025                         if (!sb_rdonly(sb))
4026                                 es->s_flags |=
4027                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4028 #endif
4029                 }
4030         }
4031 
4032         /* Handle clustersize */
4033         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4034         has_bigalloc = ext4_has_feature_bigalloc(sb);
4035         if (has_bigalloc) {
4036                 if (clustersize < blocksize) {
4037                         ext4_msg(sb, KERN_ERR,
4038                                  "cluster size (%d) smaller than "
4039                                  "block size (%d)", clustersize, blocksize);
4040                         goto failed_mount;
4041                 }
4042                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4043                         le32_to_cpu(es->s_log_block_size);
4044                 sbi->s_clusters_per_group =
4045                         le32_to_cpu(es->s_clusters_per_group);
4046                 if (sbi->s_clusters_per_group > blocksize * 8) {
4047                         ext4_msg(sb, KERN_ERR,
4048                                  "#clusters per group too big: %lu",
4049                                  sbi->s_clusters_per_group);
4050                         goto failed_mount;
4051                 }
4052                 if (sbi->s_blocks_per_group !=
4053                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4054                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4055                                  "clusters per group (%lu) inconsistent",
4056                                  sbi->s_blocks_per_group,
4057                                  sbi->s_clusters_per_group);
4058                         goto failed_mount;
4059                 }
4060         } else {
4061                 if (clustersize != blocksize) {
4062                         ext4_msg(sb, KERN_ERR,
4063                                  "fragment/cluster size (%d) != "
4064                                  "block size (%d)", clustersize, blocksize);
4065                         goto failed_mount;
4066                 }
4067                 if (sbi->s_blocks_per_group > blocksize * 8) {
4068                         ext4_msg(sb, KERN_ERR,
4069                                  "#blocks per group too big: %lu",
4070                                  sbi->s_blocks_per_group);
4071                         goto failed_mount;
4072                 }
4073                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4074                 sbi->s_cluster_bits = 0;
4075         }
4076         sbi->s_cluster_ratio = clustersize / blocksize;
4077 
4078         /* Do we have standard group size of clustersize * 8 blocks ? */
4079         if (sbi->s_blocks_per_group == clustersize << 3)
4080                 set_opt2(sb, STD_GROUP_SIZE);
4081 
4082         /*
4083          * Test whether we have more sectors than will fit in sector_t,
4084          * and whether the max offset is addressable by the page cache.
4085          */
4086         err = generic_check_addressable(sb->s_blocksize_bits,
4087                                         ext4_blocks_count(es));
4088         if (err) {
4089                 ext4_msg(sb, KERN_ERR, "filesystem"
4090                          " too large to mount safely on this system");
4091                 if (sizeof(sector_t) < 8)
4092                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
4093                 goto failed_mount;
4094         }
4095 
4096         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4097                 goto cantfind_ext4;
4098 
4099         /* check blocks count against device size */
4100         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4101         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4102                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4103                        "exceeds size of device (%llu blocks)",
4104                        ext4_blocks_count(es), blocks_count);
4105                 goto failed_mount;
4106         }
4107 
4108         /*
4109          * It makes no sense for the first data block to be beyond the end
4110          * of the filesystem.
4111          */
4112         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4113                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4114                          "block %u is beyond end of filesystem (%llu)",
4115                          le32_to_cpu(es->s_first_data_block),
4116                          ext4_blocks_count(es));
4117                 goto failed_mount;
4118         }
4119         if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4120             (sbi->s_cluster_ratio == 1)) {
4121                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4122                          "block is 0 with a 1k block and cluster size");
4123                 goto failed_mount;
4124         }
4125 
4126         blocks_count = (ext4_blocks_count(es) -
4127                         le32_to_cpu(es->s_first_data_block) +
4128                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
4129         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4130         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4131                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4132                        "(block count %llu, first data block %u, "
4133                        "blocks per group %lu)", sbi->s_groups_count,
4134                        ext4_blocks_count(es),
4135                        le32_to_cpu(es->s_first_data_block),
4136                        EXT4_BLOCKS_PER_GROUP(sb));
4137                 goto failed_mount;
4138         }
4139         sbi->s_groups_count = blocks_count;
4140         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4141                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4142         if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4143             le32_to_cpu(es->s_inodes_count)) {
4144                 ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4145                          le32_to_cpu(es->s_inodes_count),
4146                          ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4147                 ret = -EINVAL;
4148                 goto failed_mount;
4149         }
4150         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4151                    EXT4_DESC_PER_BLOCK(sb);
4152         if (ext4_has_feature_meta_bg(sb)) {
4153                 if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4154                         ext4_msg(sb, KERN_WARNING,
4155                                  "first meta block group too large: %u "
4156                                  "(group descriptor block count %u)",
4157                                  le32_to_cpu(es->s_first_meta_bg), db_count);
4158                         goto failed_mount;
4159                 }
4160         }
4161         sbi->s_group_desc = kvmalloc_array(db_count,
4162                                            sizeof(struct buffer_head *),
4163                                            GFP_KERNEL);
4164         if (sbi->s_group_desc == NULL) {
4165                 ext4_msg(sb, KERN_ERR, "not enough memory");
4166                 ret = -ENOMEM;
4167                 goto failed_mount;
4168         }
4169 
4170         bgl_lock_init(sbi->s_blockgroup_lock);
4171 
4172         /* Pre-read the descriptors into the buffer cache */
4173         for (i = 0; i < db_count; i++) {
4174                 block = descriptor_loc(sb, logical_sb_block, i);
4175                 sb_breadahead(sb, block);
4176         }
4177 
4178         for (i = 0; i < db_count; i++) {
4179                 block = descriptor_loc(sb, logical_sb_block, i);
4180                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4181                 if (!sbi->s_group_desc[i]) {
4182                         ext4_msg(sb, KERN_ERR,
4183                                "can't read group descriptor %d", i);
4184                         db_count = i;
4185                         goto failed_mount2;
4186                 }
4187         }
4188         sbi->s_gdb_count = db_count;
4189         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4190                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4191                 ret = -EFSCORRUPTED;
4192                 goto failed_mount2;
4193         }
4194 
4195         timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4196 
4197         /* Register extent status tree shrinker */
4198         if (ext4_es_register_shrinker(sbi))
4199                 goto failed_mount3;
4200 
4201         sbi->s_stripe = ext4_get_stripe_size(sbi);
4202         sbi->s_extent_max_zeroout_kb = 32;
4203 
4204         /*
4205          * set up enough so that it can read an inode
4206          */
4207         sb->s_op = &ext4_sops;
4208         sb->s_export_op = &ext4_export_ops;
4209         sb->s_xattr = ext4_xattr_handlers;
4210 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4211         sb->s_cop = &ext4_cryptops;
4212 #endif
4213 #ifdef CONFIG_QUOTA
4214         sb->dq_op = &ext4_quota_operations;
4215         if (ext4_has_feature_quota(sb))
4216                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
4217         else
4218                 sb->s_qcop = &ext4_qctl_operations;
4219         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4220 #endif
4221         memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4222 
4223         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4224         mutex_init(&sbi->s_orphan_lock);
4225 
4226         sb->s_root = NULL;
4227 
4228         needs_recovery = (es->s_last_orphan != 0 ||
4229                           ext4_has_feature_journal_needs_recovery(sb));
4230 
4231         if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4232                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4233                         goto failed_mount3a;
4234 
4235         /*
4236          * The first inode we look at is the journal inode.  Don't try
4237          * root first: it may be modified in the journal!
4238          */
4239         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4240                 err = ext4_load_journal(sb, es, journal_devnum);
4241                 if (err)
4242                         goto failed_mount3a;
4243         } else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4244                    ext4_has_feature_journal_needs_recovery(sb)) {
4245                 ext4_msg(sb, KERN_ERR, "required journal recovery "
4246                        "suppressed and not mounted read-only");
4247                 goto failed_mount_wq;
4248         } else {
4249                 /* Nojournal mode, all journal mount options are illegal */
4250                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4251                         ext4_msg(sb, KERN_ERR, "can't mount with "
4252                                  "journal_checksum, fs mounted w/o journal");
4253                         goto failed_mount_wq;
4254                 }
4255                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4256                         ext4_msg(sb, KERN_ERR, "can't mount with "
4257                                  "journal_async_commit, fs mounted w/o journal");
4258                         goto failed_mount_wq;
4259                 }
4260                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4261                         ext4_msg(sb, KERN_ERR, "can't mount with "
4262                                  "commit=%lu, fs mounted w/o journal",
4263                                  sbi->s_commit_interval / HZ);
4264                         goto failed_mount_wq;
4265                 }
4266                 if (EXT4_MOUNT_DATA_FLAGS &
4267                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4268                         ext4_msg(sb, KERN_ERR, "can't mount with "
4269                                  "data=, fs mounted w/o journal");
4270                         goto failed_mount_wq;
4271                 }
4272                 sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4273                 clear_opt(sb, JOURNAL_CHECKSUM);
4274                 clear_opt(sb, DATA_FLAGS);
4275                 sbi->s_journal = NULL;
4276                 needs_recovery = 0;
4277                 goto no_journal;
4278         }
4279 
4280         if (ext4_has_feature_64bit(sb) &&
4281             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4282                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
4283                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4284                 goto failed_mount_wq;
4285         }
4286 
4287         if (!set_journal_csum_feature_set(sb)) {
4288                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4289                          "feature set");
4290                 goto failed_mount_wq;
4291         }
4292 
4293         /* We have now updated the journal if required, so we can
4294          * validate the data journaling mode. */
4295         switch (test_opt(sb, DATA_FLAGS)) {
4296         case 0:
4297                 /* No mode set, assume a default based on the journal
4298                  * capabilities: ORDERED_DATA if the journal can
4299                  * cope, else JOURNAL_DATA
4300                  */
4301                 if (jbd2_journal_check_available_features
4302                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4303                         set_opt(sb, ORDERED_DATA);
4304                         sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4305                 } else {
4306                         set_opt(sb, JOURNAL_DATA);
4307                         sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4308                 }
4309                 break;
4310 
4311         case EXT4_MOUNT_ORDERED_DATA:
4312         case EXT4_MOUNT_WRITEBACK_DATA:
4313                 if (!jbd2_journal_check_available_features
4314                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4315                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4316                                "requested data journaling mode");
4317                         goto failed_mount_wq;
4318                 }
4319         default:
4320                 break;
4321         }
4322 
4323         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4324             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4325                 ext4_msg(sb, KERN_ERR, "can't mount with "
4326                         "journal_async_commit in data=ordered mode");
4327                 goto failed_mount_wq;
4328         }
4329 
4330         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4331 
4332         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4333 
4334 no_journal:
4335         if (!test_opt(sb, NO_MBCACHE)) {
4336                 sbi->s_ea_block_cache = ext4_xattr_create_cache();
4337                 if (!sbi->s_ea_block_cache) {
4338                         ext4_msg(sb, KERN_ERR,
4339                                  "Failed to create ea_block_cache");
4340                         goto failed_mount_wq;
4341                 }
4342 
4343                 if (ext4_has_feature_ea_inode(sb)) {
4344                         sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4345                         if (!sbi->s_ea_inode_cache) {
4346                                 ext4_msg(sb, KERN_ERR,
4347                                          "Failed to create ea_inode_cache");
4348                                 goto failed_mount_wq;
4349                         }
4350                 }
4351         }
4352 
4353         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4354             (blocksize != PAGE_SIZE)) {
4355                 ext4_msg(sb, KERN_ERR,
4356                          "Unsupported blocksize for fs encryption");
4357                 goto failed_mount_wq;
4358         }
4359 
4360         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4361             !ext4_has_feature_encrypt(sb)) {
4362                 ext4_set_feature_encrypt(sb);
4363                 ext4_commit_super(sb, 1);
4364         }
4365 
4366         /*
4367          * Get the # of file system overhead blocks from the
4368          * superblock if present.
4369          */
4370         if (es->s_overhead_clusters)
4371                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4372         else {
4373                 err = ext4_calculate_overhead(sb);
4374                 if (err)
4375                         goto failed_mount_wq;
4376         }
4377 
4378         /*
4379          * The maximum number of concurrent works can be high and
4380          * concurrency isn't really necessary.  Limit it to 1.
4381          */
4382         EXT4_SB(sb)->rsv_conversion_wq =
4383                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4384         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4385                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4386                 ret = -ENOMEM;
4387                 goto failed_mount4;
4388         }
4389 
4390         /*
4391          * The jbd2_journal_load will have done any necessary log recovery,
4392          * so we can safely mount the rest of the filesystem now.
4393          */
4394 
4395         root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4396         if (IS_ERR(root)) {
4397                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4398                 ret = PTR_ERR(root);
4399                 root = NULL;
4400                 goto failed_mount4;
4401         }
4402         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4403                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4404                 iput(root);
4405                 goto failed_mount4;
4406         }
4407         sb->s_root = d_make_root(root);
4408         if (!sb->s_root) {
4409                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4410                 ret = -ENOMEM;
4411                 goto failed_mount4;
4412         }
4413 
4414         ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4415         if (ret == -EROFS) {
4416                 sb->s_flags |= SB_RDONLY;
4417                 ret = 0;
4418         } else if (ret)
4419                 goto failed_mount4a;
4420 
4421         ext4_clamp_want_extra_isize(sb);
4422 
4423         ext4_set_resv_clusters(sb);
4424 
4425         err = ext4_setup_system_zone(sb);
4426         if (err) {
4427                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4428                          "zone (%d)", err);
4429                 goto failed_mount4a;
4430         }
4431 
4432         ext4_ext_init(sb);
4433         err = ext4_mb_init(sb);
4434         if (err) {
4435                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4436                          err);
4437                 goto failed_mount5;
4438         }
4439 
4440         block = ext4_count_free_clusters(sb);
4441         ext4_free_blocks_count_set(sbi->s_es, 
4442                                    EXT4_C2B(sbi, block));
4443         ext4_superblock_csum_set(sb);
4444         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4445                                   GFP_KERNEL);
4446         if (!err) {
4447                 unsigned long freei = ext4_count_free_inodes(sb);
4448                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4449                 ext4_superblock_csum_set(sb);
4450                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4451                                           GFP_KERNEL);
4452         }
4453         if (!err)
4454                 err = percpu_counter_init(&sbi->s_dirs_counter,
4455                                           ext4_count_dirs(sb), GFP_KERNEL);
4456         if (!err)
4457                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4458                                           GFP_KERNEL);
4459         if (!err)
4460                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4461 
4462         if (err) {
4463                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4464                 goto failed_mount6;
4465         }
4466 
4467         if (ext4_has_feature_flex_bg(sb))
4468                 if (!ext4_fill_flex_info(sb)) {
4469                         ext4_msg(sb, KERN_ERR,
4470                                "unable to initialize "
4471                                "flex_bg meta info!");
4472                         goto failed_mount6;
4473                 }
4474 
4475         err = ext4_register_li_request(sb, first_not_zeroed);
4476         if (err)
4477                 goto failed_mount6;
4478 
4479         err = ext4_register_sysfs(sb);
4480         if (err)
4481                 goto failed_mount7;
4482 
4483 #ifdef CONFIG_QUOTA
4484         /* Enable quota usage during mount. */
4485         if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4486                 err = ext4_enable_quotas(sb);
4487                 if (err)
4488                         goto failed_mount8;
4489         }
4490 #endif  /* CONFIG_QUOTA */
4491 
4492         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4493         ext4_orphan_cleanup(sb, es);
4494         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4495         if (needs_recovery) {
4496                 ext4_msg(sb, KERN_INFO, "recovery complete");
4497                 ext4_mark_recovery_complete(sb, es);
4498         }
4499         if (EXT4_SB(sb)->s_journal) {
4500                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4501                         descr = " journalled data mode";
4502                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4503                         descr = " ordered data mode";
4504                 else
4505                         descr = " writeback data mode";
4506         } else
4507                 descr = "out journal";
4508 
4509         if (test_opt(sb, DISCARD)) {
4510                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4511                 if (!blk_queue_discard(q))
4512                         ext4_msg(sb, KERN_WARNING,
4513                                  "mounting with \"discard\" option, but "
4514                                  "the device does not support discard");
4515         }
4516 
4517         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4518                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4519                          "Opts: %.*s%s%s", descr,
4520                          (int) sizeof(sbi->s_es->s_mount_opts),
4521                          sbi->s_es->s_mount_opts,
4522                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4523 
4524         if (es->s_error_count)
4525                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4526 
4527         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4528         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4529         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4530         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4531 
4532         kfree(orig_data);
4533         return 0;
4534 
4535 cantfind_ext4:
4536         if (!silent)
4537                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4538         goto failed_mount;
4539 
4540 #ifdef CONFIG_QUOTA
4541 failed_mount8:
4542         ext4_unregister_sysfs(sb);
4543 #endif
4544 failed_mount7:
4545         ext4_unregister_li_request(sb);
4546 failed_mount6:
4547         ext4_mb_release(sb);
4548         if (sbi->s_flex_groups)
4549                 kvfree(sbi->s_flex_groups);
4550         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4551         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4552         percpu_counter_destroy(&sbi->s_dirs_counter);
4553         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4554         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
4555 failed_mount5:
4556         ext4_ext_release(sb);
4557         ext4_release_system_zone(sb);
4558 failed_mount4a:
4559         dput(sb->s_root);
4560         sb->s_root = NULL;
4561 failed_mount4:
4562         ext4_msg(sb, KERN_ERR, "mount failed");
4563         if (EXT4_SB(sb)->rsv_conversion_wq)
4564                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4565 failed_mount_wq:
4566         ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4567         sbi->s_ea_inode_cache = NULL;
4568 
4569         ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4570         sbi->s_ea_block_cache = NULL;
4571 
4572         if (sbi->s_journal) {
4573                 jbd2_journal_destroy(sbi->s_journal);
4574                 sbi->s_journal = NULL;
4575         }
4576 failed_mount3a:
4577         ext4_es_unregister_shrinker(sbi);
4578 failed_mount3:
4579         del_timer_sync(&sbi->s_err_report);
4580         if (sbi->s_mmp_tsk)
4581                 kthread_stop(sbi->s_mmp_tsk);
4582 failed_mount2:
4583         for (i = 0; i < db_count; i++)
4584                 brelse(sbi->s_group_desc[i]);
4585         kvfree(sbi->s_group_desc);
4586 failed_mount:
4587         if (sbi->s_chksum_driver)
4588                 crypto_free_shash(sbi->s_chksum_driver);
4589 #ifdef CONFIG_QUOTA
4590         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4591                 kfree(sbi->s_qf_names[i]);
4592 #endif
4593         ext4_blkdev_remove(sbi);
4594         brelse(bh);
4595 out_fail:
4596         sb->s_fs_info = NULL;
4597         kfree(sbi->s_blockgroup_lock);
4598 out_free_base:
4599         kfree(sbi);
4600         kfree(orig_data);
4601         fs_put_dax(dax_dev);
4602         return err ? err : ret;
4603 }
4604 
4605 /*
4606  * Setup any per-fs journal parameters now.  We'll do this both on
4607  * initial mount, once the journal has been initialised but before we've
4608  * done any recovery; and again on any subsequent remount.
4609  */
4610 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4611 {
4612         struct ext4_sb_info *sbi = EXT4_SB(sb);
4613 
4614         journal->j_commit_interval = sbi->s_commit_interval;
4615         journal->j_min_batch_time = sbi->s_min_batch_time;
4616         journal->j_max_batch_time = sbi->s_max_batch_time;
4617 
4618         write_lock(&journal->j_state_lock);
4619         if (test_opt(sb, BARRIER))
4620                 journal->j_flags |= JBD2_BARRIER;
4621         else
4622                 journal->j_flags &= ~JBD2_BARRIER;
4623         if (test_opt(sb, DATA_ERR_ABORT))
4624                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4625         else
4626                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4627         write_unlock(&journal->j_state_lock);
4628 }
4629 
4630 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4631                                              unsigned int journal_inum)
4632 {
4633         struct inode *journal_inode;
4634 
4635         /*
4636          * Test for the existence of a valid inode on disk.  Bad things
4637          * happen if we iget() an unused inode, as the subsequent iput()
4638          * will try to delete it.
4639          */
4640         journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4641         if (IS_ERR(journal_inode)) {
4642                 ext4_msg(sb, KERN_ERR, "no journal found");
4643                 return NULL;
4644         }
4645         if (!journal_inode->i_nlink) {
4646                 make_bad_inode(journal_inode);
4647                 iput(journal_inode);
4648                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4649                 return NULL;
4650         }
4651 
4652         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4653                   journal_inode, journal_inode->i_size);
4654         if (!S_ISREG(journal_inode->i_mode)) {
4655                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4656                 iput(journal_inode);
4657                 return NULL;
4658         }
4659         return journal_inode;
4660 }
4661 
4662 static journal_t *ext4_get_journal(struct super_block *sb,
4663                                    unsigned int journal_inum)
4664 {
4665         struct inode *journal_inode;
4666         journal_t *journal;
4667 
4668         BUG_ON(!ext4_has_feature_journal(sb));
4669 
4670         journal_inode = ext4_get_journal_inode(sb, journal_inum);
4671         if (!journal_inode)
4672                 return NULL;
4673 
4674         journal = jbd2_journal_init_inode(journal_inode);
4675         if (!journal) {
4676                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4677                 iput(journal_inode);
4678                 return NULL;
4679         }
4680         journal->j_private = sb;
4681         ext4_init_journal_params(sb, journal);
4682         return journal;
4683 }
4684 
4685 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4686                                        dev_t j_dev)
4687 {
4688         struct buffer_head *bh;
4689         journal_t *journal;
4690         ext4_fsblk_t start;
4691         ext4_fsblk_t len;
4692         int hblock, blocksize;
4693         ext4_fsblk_t sb_block;
4694         unsigned long offset;
4695         struct ext4_super_block *es;
4696         struct block_device *bdev;
4697 
4698         BUG_ON(!ext4_has_feature_journal(sb));
4699 
4700         bdev = ext4_blkdev_get(j_dev, sb);
4701         if (bdev == NULL)
4702                 return NULL;
4703 
4704         blocksize = sb->s_blocksize;
4705         hblock = bdev_logical_block_size(bdev);
4706         if (blocksize < hblock) {
4707                 ext4_msg(sb, KERN_ERR,
4708                         "blocksize too small for journal device");
4709                 goto out_bdev;
4710         }
4711 
4712         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4713         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4714         set_blocksize(bdev, blocksize);
4715         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4716                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4717                        "external journal");
4718                 goto out_bdev;
4719         }
4720 
4721         es = (struct ext4_super_block *) (bh->b_data + offset);
4722         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4723             !(le32_to_cpu(es->s_feature_incompat) &
4724               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4725                 ext4_msg(sb, KERN_ERR, "external journal has "
4726                                         "bad superblock");
4727                 brelse(bh);
4728                 goto out_bdev;
4729         }
4730 
4731         if ((le32_to_cpu(es->s_feature_ro_compat) &
4732              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4733             es->s_checksum != ext4_superblock_csum(sb, es)) {
4734                 ext4_msg(sb, KERN_ERR, "external journal has "
4735                                        "corrupt superblock");
4736                 brelse(bh);
4737                 goto out_bdev;
4738         }
4739 
4740         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4741                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4742                 brelse(bh);
4743                 goto out_bdev;
4744         }
4745 
4746         len = ext4_blocks_count(es);
4747         start = sb_block + 1;
4748         brelse(bh);     /* we're done with the superblock */
4749 
4750         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4751                                         start, len, blocksize);
4752         if (!journal) {
4753                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4754                 goto out_bdev;
4755         }
4756         journal->j_private = sb;
4757         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4758         wait_on_buffer(journal->j_sb_buffer);
4759         if (!buffer_uptodate(journal->j_sb_buffer)) {
4760                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4761                 goto out_journal;
4762         }
4763         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4764                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4765                                         "user (unsupported) - %d",
4766                         be32_to_cpu(journal->j_superblock->s_nr_users));
4767                 goto out_journal;
4768         }
4769         EXT4_SB(sb)->journal_bdev = bdev;
4770         ext4_init_journal_params(sb, journal);
4771         return journal;
4772 
4773 out_journal:
4774         jbd2_journal_destroy(journal);
4775 out_bdev:
4776         ext4_blkdev_put(bdev);
4777         return NULL;
4778 }
4779 
4780 static int ext4_load_journal(struct super_block *sb,
4781                              struct ext4_super_block *es,
4782                              unsigned long journal_devnum)
4783 {
4784         journal_t *journal;
4785         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4786         dev_t journal_dev;
4787         int err = 0;
4788         int really_read_only;
4789 
4790         BUG_ON(!ext4_has_feature_journal(sb));
4791 
4792         if (journal_devnum &&
4793             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4794                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4795                         "numbers have changed");
4796                 journal_dev = new_decode_dev(journal_devnum);
4797         } else
4798                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4799 
4800         really_read_only = bdev_read_only(sb->s_bdev);
4801 
4802         /*
4803          * Are we loading a blank journal or performing recovery after a
4804          * crash?  For recovery, we need to check in advance whether we
4805          * can get read-write access to the device.
4806          */
4807         if (ext4_has_feature_journal_needs_recovery(sb)) {
4808                 if (sb_rdonly(sb)) {
4809                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4810                                         "required on readonly filesystem");
4811                         if (really_read_only) {
4812                                 ext4_msg(sb, KERN_ERR, "write access "
4813                                         "unavailable, cannot proceed "
4814                                         "(try mounting with noload)");
4815                                 return -EROFS;
4816                         }
4817                         ext4_msg(sb, KERN_INFO, "write access will "
4818                                "be enabled during recovery");
4819                 }
4820         }
4821 
4822         if (journal_inum && journal_dev) {
4823                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4824                        "and inode journals!");
4825                 return -EINVAL;
4826         }
4827 
4828         if (journal_inum) {
4829                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4830                         return -EINVAL;
4831         } else {
4832                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4833                         return -EINVAL;
4834         }
4835 
4836         if (!(journal->j_flags & JBD2_BARRIER))
4837                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4838 
4839         if (!ext4_has_feature_journal_needs_recovery(sb))
4840                 err = jbd2_journal_wipe(journal, !really_read_only);
4841         if (!err) {
4842                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4843                 if (save)
4844                         memcpy(save, ((char *) es) +
4845                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4846                 err = jbd2_journal_load(journal);
4847                 if (save)
4848                         memcpy(((char *) es) + EXT4_S_ERR_START,
4849                                save, EXT4_S_ERR_LEN);
4850                 kfree(save);
4851         }
4852 
4853         if (err) {
4854                 ext4_msg(sb, KERN_ERR, "error loading journal");
4855                 jbd2_journal_destroy(journal);
4856                 return err;
4857         }
4858 
4859         EXT4_SB(sb)->s_journal = journal;
4860         ext4_clear_journal_err(sb, es);
4861 
4862         if (!really_read_only && journal_devnum &&
4863             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4864                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4865 
4866                 /* Make sure we flush the recovery flag to disk. */
4867                 ext4_commit_super(sb, 1);
4868         }
4869 
4870         return 0;
4871 }
4872 
4873 static int ext4_commit_super(struct super_block *sb, int sync)
4874 {
4875         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4876         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4877         int error = 0;
4878 
4879         if (!sbh || block_device_ejected(sb))
4880                 return error;
4881 
4882         /*
4883          * The superblock bh should be mapped, but it might not be if the
4884          * device was hot-removed. Not much we can do but fail the I/O.
4885          */
4886         if (!buffer_mapped(sbh))
4887                 return error;
4888 
4889         /*
4890          * If the file system is mounted read-only, don't update the
4891          * superblock write time.  This avoids updating the superblock
4892          * write time when we are mounting the root file system
4893          * read/only but we need to replay the journal; at that point,
4894          * for people who are east of GMT and who make their clock
4895          * tick in localtime for Windows bug-for-bug compatibility,
4896          * the clock is set in the future, and this will cause e2fsck
4897          * to complain and force a full file system check.
4898          */
4899         if (!(sb->s_flags & SB_RDONLY))
4900                 ext4_update_tstamp(es, s_wtime);
4901         if (sb->s_bdev->bd_part)
4902                 es->s_kbytes_written =
4903                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4904                             ((part_stat_read(sb->s_bdev->bd_part,
4905                                              sectors[STAT_WRITE]) -
4906                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4907         else
4908                 es->s_kbytes_written =
4909                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4910         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4911                 ext4_free_blocks_count_set(es,
4912                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4913                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4914         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4915                 es->s_free_inodes_count =
4916                         cpu_to_le32(percpu_counter_sum_positive(
4917                                 &EXT4_SB(sb)->s_freeinodes_counter));
4918         BUFFER_TRACE(sbh, "marking dirty");
4919         ext4_superblock_csum_set(sb);
4920         if (sync)
4921                 lock_buffer(sbh);
4922         if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
4923                 /*
4924                  * Oh, dear.  A previous attempt to write the
4925                  * superblock failed.  This could happen because the
4926                  * USB device was yanked out.  Or it could happen to
4927                  * be a transient write error and maybe the block will
4928                  * be remapped.  Nothing we can do but to retry the
4929                  * write and hope for the best.
4930                  */
4931                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4932                        "superblock detected");
4933                 clear_buffer_write_io_error(sbh);
4934                 set_buffer_uptodate(sbh);
4935         }
4936         mark_buffer_dirty(sbh);
4937         if (sync) {
4938                 unlock_buffer(sbh);
4939                 error = __sync_dirty_buffer(sbh,
4940                         REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4941                 if (buffer_write_io_error(sbh)) {
4942                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4943                                "superblock");
4944                         clear_buffer_write_io_error(sbh);
4945                         set_buffer_uptodate(sbh);
4946                 }
4947         }
4948         return error;
4949 }
4950 
4951 /*
4952  * Have we just finished recovery?  If so, and if we are mounting (or
4953  * remounting) the filesystem readonly, then we will end up with a
4954  * consistent fs on disk.  Record that fact.
4955  */
4956 static void ext4_mark_recovery_complete(struct super_block *sb,
4957                                         struct ext4_super_block *es)
4958 {
4959         journal_t *journal = EXT4_SB(sb)->s_journal;
4960 
4961         if (!ext4_has_feature_journal(sb)) {
4962                 BUG_ON(journal != NULL);
4963                 return;
4964         }
4965         jbd2_journal_lock_updates(journal);
4966         if (jbd2_journal_flush(journal) < 0)
4967                 goto out;
4968 
4969         if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
4970                 ext4_clear_feature_journal_needs_recovery(sb);
4971                 ext4_commit_super(sb, 1);
4972         }
4973 
4974 out:
4975         jbd2_journal_unlock_updates(journal);
4976 }
4977 
4978 /*
4979  * If we are mounting (or read-write remounting) a filesystem whose journal
4980  * has recorded an error from a previous lifetime, move that error to the
4981  * main filesystem now.
4982  */
4983 static void ext4_clear_journal_err(struct super_block *sb,
4984                                    struct ext4_super_block *es)
4985 {
4986         journal_t *journal;
4987         int j_errno;
4988         const char *errstr;
4989 
4990         BUG_ON(!ext4_has_feature_journal(sb));
4991 
4992         journal = EXT4_SB(sb)->s_journal;
4993 
4994         /*
4995          * Now check for any error status which may have been recorded in the
4996          * journal by a prior ext4_error() or ext4_abort()
4997          */
4998 
4999         j_errno = jbd2_journal_errno(journal);
5000         if (j_errno) {
5001                 char nbuf[16];
5002 
5003                 errstr = ext4_decode_error(sb, j_errno, nbuf);
5004                 ext4_warning(sb, "Filesystem error recorded "
5005                              "from previous mount: %s", errstr);
5006                 ext4_warning(sb, "Marking fs in need of filesystem check.");
5007 
5008                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5009                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5010                 ext4_commit_super(sb, 1);
5011 
5012                 jbd2_journal_clear_err(journal);
5013                 jbd2_journal_update_sb_errno(journal);
5014         }
5015 }
5016 
5017 /*
5018  * Force the running and committing transactions to commit,
5019  * and wait on the commit.
5020  */
5021 int ext4_force_commit(struct super_block *sb)
5022 {
5023         journal_t *journal;
5024 
5025         if (sb_rdonly(sb))
5026                 return 0;
5027 
5028         journal = EXT4_SB(sb)->s_journal;
5029         return ext4_journal_force_commit(journal);
5030 }
5031 
5032 static int ext4_sync_fs(struct super_block *sb, int wait)
5033 {
5034         int ret = 0;
5035         tid_t target;
5036         bool needs_barrier = false;
5037         struct ext4_sb_info *sbi = EXT4_SB(sb);
5038 
5039         if (unlikely(ext4_forced_shutdown(sbi)))
5040                 return 0;
5041 
5042         trace_ext4_sync_fs(sb, wait);
5043         flush_workqueue(sbi->rsv_conversion_wq);
5044         /*
5045          * Writeback quota in non-journalled quota case - journalled quota has
5046          * no dirty dquots
5047          */
5048         dquot_writeback_dquots(sb, -1);
5049         /*
5050          * Data writeback is possible w/o journal transaction, so barrier must
5051          * being sent at the end of the function. But we can skip it if
5052          * transaction_commit will do it for us.
5053          */
5054         if (sbi->s_journal) {
5055                 target = jbd2_get_latest_transaction(sbi->s_journal);
5056                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5057                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5058                         needs_barrier = true;
5059 
5060                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5061                         if (wait)
5062                                 ret = jbd2_log_wait_commit(sbi->s_journal,
5063                                                            target);
5064                 }
5065         } else if (wait && test_opt(sb, BARRIER))
5066                 needs_barrier = true;
5067         if (needs_barrier) {
5068                 int err;
5069                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5070                 if (!ret)
5071                         ret = err;
5072         }
5073 
5074         return ret;
5075 }
5076 
5077 /*
5078  * LVM calls this function before a (read-only) snapshot is created.  This
5079  * gives us a chance to flush the journal completely and mark the fs clean.
5080  *
5081  * Note that only this function cannot bring a filesystem to be in a clean
5082  * state independently. It relies on upper layer to stop all data & metadata
5083  * modifications.
5084  */
5085 static int ext4_freeze(struct super_block *sb)
5086 {
5087         int error = 0;
5088         journal_t *journal;
5089 
5090         if (sb_rdonly(sb))
5091                 return 0;
5092 
5093         journal = EXT4_SB(sb)->s_journal;
5094 
5095         if (journal) {
5096                 /* Now we set up the journal barrier. */
5097                 jbd2_journal_lock_updates(journal);
5098 
5099                 /*
5100                  * Don't clear the needs_recovery flag if we failed to
5101                  * flush the journal.
5102                  */
5103                 error = jbd2_journal_flush(journal);
5104                 if (error < 0)
5105                         goto out;
5106 
5107                 /* Journal blocked and flushed, clear needs_recovery flag. */
5108                 ext4_clear_feature_journal_needs_recovery(sb);
5109         }
5110 
5111         error = ext4_commit_super(sb, 1);
5112 out:
5113         if (journal)
5114                 /* we rely on upper layer to stop further updates */
5115                 jbd2_journal_unlock_updates(journal);
5116         return error;
5117 }
5118 
5119 /*
5120  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5121  * flag here, even though the filesystem is not technically dirty yet.
5122  */
5123 static int ext4_unfreeze(struct super_block *sb)
5124 {
5125         if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5126                 return 0;
5127 
5128         if (EXT4_SB(sb)->s_journal) {
5129                 /* Reset the needs_recovery flag before the fs is unlocked. */
5130                 ext4_set_feature_journal_needs_recovery(sb);
5131         }
5132 
5133         ext4_commit_super(sb, 1);
5134         return 0;
5135 }
5136 
5137 /*
5138  * Structure to save mount options for ext4_remount's benefit
5139  */
5140 struct ext4_mount_options {
5141         unsigned long s_mount_opt;
5142         unsigned long s_mount_opt2;
5143         kuid_t s_resuid;
5144         kgid_t s_resgid;
5145         unsigned long s_commit_interval;
5146         u32 s_min_batch_time, s_max_batch_time;
5147 #ifdef CONFIG_QUOTA
5148         int s_jquota_fmt;
5149         char *s_qf_names[EXT4_MAXQUOTAS];
5150 #endif
5151 };
5152 
5153 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5154 {
5155         struct ext4_super_block *es;
5156         struct ext4_sb_info *sbi = EXT4_SB(sb);
5157         unsigned long old_sb_flags;
5158         struct ext4_mount_options old_opts;
5159         int enable_quota = 0;
5160         ext4_group_t g;
5161         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5162         int err = 0;
5163 #ifdef CONFIG_QUOTA
5164         int i, j;
5165         char *to_free[EXT4_MAXQUOTAS];
5166 #endif
5167         char *orig_data = kstrdup(data, GFP_KERNEL);
5168 
5169         if (data && !orig_data)
5170                 return -ENOMEM;
5171 
5172         /* Store the original options */
5173         old_sb_flags = sb->s_flags;
5174         old_opts.s_mount_opt = sbi->s_mount_opt;
5175         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5176         old_opts.s_resuid = sbi->s_resuid;
5177         old_opts.s_resgid = sbi->s_resgid;
5178         old_opts.s_commit_interval = sbi->s_commit_interval;
5179         old_opts.s_min_batch_time = sbi->s_min_batch_time;
5180         old_opts.s_max_batch_time = sbi->s_max_batch_time;
5181 #ifdef CONFIG_QUOTA
5182         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5183         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5184                 if (sbi->s_qf_names[i]) {
5185                         char *qf_name = get_qf_name(sb, sbi, i);
5186 
5187                         old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5188                         if (!old_opts.s_qf_names[i]) {
5189                                 for (j = 0; j < i; j++)
5190                                         kfree(old_opts.s_qf_names[j]);
5191                                 kfree(orig_data);
5192                                 return -ENOMEM;
5193                         }
5194                 } else
5195                         old_opts.s_qf_names[i] = NULL;
5196 #endif
5197         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5198                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5199 
5200         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5201                 err = -EINVAL;
5202                 goto restore_opts;
5203         }
5204 
5205         ext4_clamp_want_extra_isize(sb);
5206 
5207         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5208             test_opt(sb, JOURNAL_CHECKSUM)) {
5209                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5210                          "during remount not supported; ignoring");
5211                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5212         }
5213 
5214         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5215                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5216                         ext4_msg(sb, KERN_ERR, "can't mount with "
5217                                  "both data=journal and delalloc");
5218                         err = -EINVAL;
5219                         goto restore_opts;
5220                 }
5221                 if (test_opt(sb, DIOREAD_NOLOCK)) {
5222                         ext4_msg(sb, KERN_ERR, "can't mount with "
5223                                  "both data=journal and dioread_nolock");
5224                         err = -EINVAL;
5225                         goto restore_opts;
5226                 }
5227                 if (test_opt(sb, DAX)) {
5228                         ext4_msg(sb, KERN_ERR, "can't mount with "
5229                                  "both data=journal and dax");
5230                         err = -EINVAL;
5231                         goto restore_opts;
5232                 }
5233         } else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5234                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5235                         ext4_msg(sb, KERN_ERR, "can't mount with "
5236                                 "journal_async_commit in data=ordered mode");
5237                         err = -EINVAL;
5238                         goto restore_opts;
5239                 }
5240         }
5241 
5242         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5243                 ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5244                 err = -EINVAL;
5245                 goto restore_opts;
5246         }
5247 
5248         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5249                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5250                         "dax flag with busy inodes while remounting");
5251                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5252         }
5253 
5254         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5255                 ext4_abort(sb, "Abort forced by user");
5256 
5257         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5258                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5259 
5260         es = sbi->s_es;
5261 
5262         if (sbi->s_journal) {
5263                 ext4_init_journal_params(sb, sbi->s_journal);
5264                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5265         }
5266 
5267         if (*flags & SB_LAZYTIME)
5268                 sb->s_flags |= SB_LAZYTIME;
5269 
5270         if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5271                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5272                         err = -EROFS;
5273                         goto restore_opts;
5274                 }
5275 
5276                 if (*flags & SB_RDONLY) {
5277                         err = sync_filesystem(sb);
5278                         if (err < 0)
5279                                 goto restore_opts;
5280                         err = dquot_suspend(sb, -1);
5281                         if (err < 0)
5282                                 goto restore_opts;
5283 
5284                         /*
5285                          * First of all, the unconditional stuff we have to do
5286                          * to disable replay of the journal when we next remount
5287                          */
5288                         sb->s_flags |= SB_RDONLY;
5289 
5290                         /*
5291                          * OK, test if we are remounting a valid rw partition
5292                          * readonly, and if so set the rdonly flag and then
5293                          * mark the partition as valid again.
5294                          */
5295                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5296                             (sbi->s_mount_state & EXT4_VALID_FS))
5297                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
5298 
5299                         if (sbi->s_journal)
5300                                 ext4_mark_recovery_complete(sb, es);
5301                         if (sbi->s_mmp_tsk)
5302                                 kthread_stop(sbi->s_mmp_tsk);
5303                 } else {
5304                         /* Make sure we can mount this feature set readwrite */
5305                         if (ext4_has_feature_readonly(sb) ||
5306                             !ext4_feature_set_ok(sb, 0)) {
5307                                 err = -EROFS;
5308                                 goto restore_opts;
5309                         }
5310                         /*
5311                          * Make sure the group descriptor checksums
5312                          * are sane.  If they aren't, refuse to remount r/w.
5313                          */
5314                         for (g = 0; g < sbi->s_groups_count; g++) {
5315                                 struct ext4_group_desc *gdp =
5316                                         ext4_get_group_desc(sb, g, NULL);
5317 
5318                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5319                                         ext4_msg(sb, KERN_ERR,
5320                "ext4_remount: Checksum for group %u failed (%u!=%u)",
5321                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5322                                                le16_to_cpu(gdp->bg_checksum));
5323                                         err = -EFSBADCRC;
5324                                         goto restore_opts;
5325                                 }
5326                         }
5327 
5328                         /*
5329                          * If we have an unprocessed orphan list hanging
5330                          * around from a previously readonly bdev mount,
5331                          * require a full umount/remount for now.
5332                          */
5333                         if (es->s_last_orphan) {
5334                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
5335                                        "remount RDWR because of unprocessed "
5336                                        "orphan inode list.  Please "
5337                                        "umount/remount instead");
5338                                 err = -EINVAL;
5339                                 goto restore_opts;
5340                         }
5341 
5342                         /*
5343                          * Mounting a RDONLY partition read-write, so reread
5344                          * and store the current valid flag.  (It may have
5345                          * been changed by e2fsck since we originally mounted
5346                          * the partition.)
5347                          */
5348                         if (sbi->s_journal)
5349                                 ext4_clear_journal_err(sb, es);
5350                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5351 
5352                         err = ext4_setup_super(sb, es, 0);
5353                         if (err)
5354                                 goto restore_opts;
5355 
5356                         sb->s_flags &= ~SB_RDONLY;
5357                         if (ext4_has_feature_mmp(sb))
5358                                 if (ext4_multi_mount_protect(sb,
5359                                                 le64_to_cpu(es->s_mmp_block))) {
5360                                         err = -EROFS;
5361                                         goto restore_opts;
5362                                 }
5363                         enable_quota = 1;
5364                 }
5365         }
5366 
5367         /*
5368          * Reinitialize lazy itable initialization thread based on
5369          * current settings
5370          */
5371         if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5372                 ext4_unregister_li_request(sb);
5373         else {
5374                 ext4_group_t first_not_zeroed;
5375                 first_not_zeroed = ext4_has_uninit_itable(sb);
5376                 ext4_register_li_request(sb, first_not_zeroed);
5377         }
5378 
5379         ext4_setup_system_zone(sb);
5380         if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5381                 err = ext4_commit_super(sb, 1);
5382                 if (err)
5383                         goto restore_opts;
5384         }
5385 
5386 #ifdef CONFIG_QUOTA
5387         /* Release old quota file names */
5388         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5389                 kfree(old_opts.s_qf_names[i]);
5390         if (enable_quota) {
5391                 if (sb_any_quota_suspended(sb))
5392                         dquot_resume(sb, -1);
5393                 else if (ext4_has_feature_quota(sb)) {
5394                         err = ext4_enable_quotas(sb);
5395                         if (err)
5396                                 goto restore_opts;
5397                 }
5398         }
5399 #endif
5400 
5401         *flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5402         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5403         kfree(orig_data);
5404         return 0;
5405 
5406 restore_opts:
5407         sb->s_flags = old_sb_flags;
5408         sbi->s_mount_opt = old_opts.s_mount_opt;
5409         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5410         sbi->s_resuid = old_opts.s_resuid;
5411         sbi->s_resgid = old_opts.s_resgid;
5412         sbi->s_commit_interval = old_opts.s_commit_interval;
5413         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5414         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5415 #ifdef CONFIG_QUOTA
5416         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5417         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5418                 to_free[i] = get_qf_name(sb, sbi, i);
5419                 rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5420         }
5421         synchronize_rcu();
5422         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5423                 kfree(to_free[i]);
5424 #endif
5425         kfree(orig_data);
5426         return err;
5427 }
5428 
5429 #ifdef CONFIG_QUOTA
5430 static int ext4_statfs_project(struct super_block *sb,
5431                                kprojid_t projid, struct kstatfs *buf)
5432 {
5433         struct kqid qid;
5434         struct dquot *dquot;
5435         u64 limit;
5436         u64 curblock;
5437 
5438         qid = make_kqid_projid(projid);
5439         dquot = dqget(sb, qid);
5440         if (IS_ERR(dquot))
5441                 return PTR_ERR(dquot);
5442         spin_lock(&dquot->dq_dqb_lock);
5443 
5444         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5445                  dquot->dq_dqb.dqb_bsoftlimit :
5446                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5447         if (limit && buf->f_blocks > limit) {
5448                 curblock = (dquot->dq_dqb.dqb_curspace +
5449                             dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5450                 buf->f_blocks = limit;
5451                 buf->f_bfree = buf->f_bavail =
5452                         (buf->f_blocks > curblock) ?
5453                          (buf->f_blocks - curblock) : 0;
5454         }
5455 
5456         limit = dquot->dq_dqb.dqb_isoftlimit ?
5457                 dquot->dq_dqb.dqb_isoftlimit :
5458                 dquot->dq_dqb.dqb_ihardlimit;
5459         if (limit && buf->f_files > limit) {
5460                 buf->f_files = limit;
5461                 buf->f_ffree =
5462                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5463                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5464         }
5465 
5466         spin_unlock(&dquot->dq_dqb_lock);
5467         dqput(dquot);
5468         return 0;
5469 }
5470 #endif
5471 
5472 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5473 {
5474         struct super_block *sb = dentry->d_sb;
5475         struct ext4_sb_info *sbi = EXT4_SB(sb);
5476         struct ext4_super_block *es = sbi->s_es;
5477         ext4_fsblk_t overhead = 0, resv_blocks;
5478         u64 fsid;
5479         s64 bfree;
5480         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5481 
5482         if (!test_opt(sb, MINIX_DF))
5483                 overhead = sbi->s_overhead;
5484 
5485         buf->f_type = EXT4_SUPER_MAGIC;
5486         buf->f_bsize = sb->s_blocksize;
5487         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5488         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5489                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5490         /* prevent underflow in case that few free space is available */
5491         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5492         buf->f_bavail = buf->f_bfree -
5493                         (ext4_r_blocks_count(es) + resv_blocks);
5494         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5495                 buf->f_bavail = 0;
5496         buf->f_files = le32_to_cpu(es->s_inodes_count);
5497         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5498         buf->f_namelen = EXT4_NAME_LEN;
5499         fsid = le64_to_cpup((void *)es->s_uuid) ^
5500                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5501         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5502         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5503 
5504 #ifdef CONFIG_QUOTA
5505         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5506             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5507                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5508 #endif
5509         return 0;
5510 }
5511 
5512 
5513 #ifdef CONFIG_QUOTA
5514 
5515 /*
5516  * Helper functions so that transaction is started before we acquire dqio_sem
5517  * to keep correct lock ordering of transaction > dqio_sem
5518  */
5519 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5520 {
5521         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5522 }
5523 
5524 static int ext4_write_dquot(struct dquot *dquot)
5525 {
5526         int ret, err;
5527         handle_t *handle;
5528         struct inode *inode;
5529 
5530         inode = dquot_to_inode(dquot);
5531         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5532                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5533         if (IS_ERR(handle))
5534                 return PTR_ERR(handle);
5535         ret = dquot_commit(dquot);
5536         err = ext4_journal_stop(handle);
5537         if (!ret)
5538                 ret = err;
5539         return ret;
5540 }
5541 
5542 static int ext4_acquire_dquot(struct dquot *dquot)
5543 {
5544         int ret, err;
5545         handle_t *handle;
5546 
5547         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5548                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5549         if (IS_ERR(handle))
5550                 return PTR_ERR(handle);
5551         ret = dquot_acquire(dquot);
5552         err = ext4_journal_stop(handle);
5553         if (!ret)
5554                 ret = err;
5555         return ret;
5556 }
5557 
5558 static int ext4_release_dquot(struct dquot *dquot)
5559 {
5560         int ret, err;
5561         handle_t *handle;
5562 
5563         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5564                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5565         if (IS_ERR(handle)) {
5566                 /* Release dquot anyway to avoid endless cycle in dqput() */
5567                 dquot_release(dquot);
5568                 return PTR_ERR(handle);
5569         }
5570         ret = dquot_release(dquot);
5571         err = ext4_journal_stop(handle);
5572         if (!ret)
5573                 ret = err;
5574         return ret;
5575 }
5576 
5577 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5578 {
5579         struct super_block *sb = dquot->dq_sb;
5580         struct ext4_sb_info *sbi = EXT4_SB(sb);
5581 
5582         /* Are we journaling quotas? */
5583         if (ext4_has_feature_quota(sb) ||
5584             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5585                 dquot_mark_dquot_dirty(dquot);
5586                 return ext4_write_dquot(dquot);
5587         } else {
5588                 return dquot_mark_dquot_dirty(dquot);
5589         }
5590 }
5591 
5592 static int ext4_write_info(struct super_block *sb, int type)
5593 {
5594         int ret, err;
5595         handle_t *handle;
5596 
5597         /* Data block + inode block */
5598         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5599         if (IS_ERR(handle))
5600                 return PTR_ERR(handle);
5601         ret = dquot_commit_info(sb, type);
5602         err = ext4_journal_stop(handle);
5603         if (!ret)
5604                 ret = err;
5605         return ret;
5606 }
5607 
5608 /*
5609  * Turn on quotas during mount time - we need to find
5610  * the quota file and such...
5611  */
5612 static int ext4_quota_on_mount(struct super_block *sb, int type)
5613 {
5614         return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5615                                         EXT4_SB(sb)->s_jquota_fmt, type);
5616 }
5617 
5618 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5619 {
5620         struct ext4_inode_info *ei = EXT4_I(inode);
5621 
5622         /* The first argument of lockdep_set_subclass has to be
5623          * *exactly* the same as the argument to init_rwsem() --- in
5624          * this case, in init_once() --- or lockdep gets unhappy
5625          * because the name of the lock is set using the
5626          * stringification of the argument to init_rwsem().
5627          */
5628         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5629         lockdep_set_subclass(&ei->i_data_sem, subclass);
5630 }
5631 
5632 /*
5633  * Standard function to be called on quota_on
5634  */
5635 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5636                          const struct path *path)
5637 {
5638         int err;
5639 
5640         if (!test_opt(sb, QUOTA))
5641                 return -EINVAL;
5642 
5643         /* Quotafile not on the same filesystem? */
5644         if (path->dentry->d_sb != sb)
5645                 return -EXDEV;
5646         /* Journaling quota? */
5647         if (EXT4_SB(sb)->s_qf_names[type]) {
5648                 /* Quotafile not in fs root? */
5649                 if (path->dentry->d_parent != sb->s_root)
5650                         ext4_msg(sb, KERN_WARNING,
5651                                 "Quota file not on filesystem root. "
5652                                 "Journaled quota will not work");
5653                 sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5654         } else {
5655                 /*
5656                  * Clear the flag just in case mount options changed since
5657                  * last time.
5658                  */
5659                 sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5660         }
5661 
5662         /*
5663          * When we journal data on quota file, we have to flush journal to see
5664          * all updates to the file when we bypass pagecache...
5665          */
5666         if (EXT4_SB(sb)->s_journal &&
5667             ext4_should_journal_data(d_inode(path->dentry))) {
5668                 /*
5669                  * We don't need to lock updates but journal_flush() could
5670                  * otherwise be livelocked...
5671                  */
5672                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5673                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5674                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5675                 if (err)
5676                         return err;
5677         }
5678 
5679         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5680         err = dquot_quota_on(sb, type, format_id, path);
5681         if (err) {
5682                 lockdep_set_quota_inode(path->dentry->d_inode,
5683                                              I_DATA_SEM_NORMAL);
5684         } else {
5685                 struct inode *inode = d_inode(path->dentry);
5686                 handle_t *handle;
5687 
5688                 /*
5689                  * Set inode flags to prevent userspace from messing with quota
5690                  * files. If this fails, we return success anyway since quotas
5691                  * are already enabled and this is not a hard failure.
5692                  */
5693                 inode_lock(inode);
5694                 handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5695                 if (IS_ERR(handle))
5696                         goto unlock_inode;
5697                 EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5698                 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5699                                 S_NOATIME | S_IMMUTABLE);
5700                 ext4_mark_inode_dirty(handle, inode);
5701                 ext4_journal_stop(handle);
5702         unlock_inode:
5703                 inode_unlock(inode);
5704         }
5705         return err;
5706 }
5707 
5708 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5709                              unsigned int flags)
5710 {
5711         int err;
5712         struct inode *qf_inode;
5713         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5714                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5715                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5716                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5717         };
5718 
5719         BUG_ON(!ext4_has_feature_quota(sb));
5720 
5721         if (!qf_inums[type])
5722                 return -EPERM;
5723 
5724         qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5725         if (IS_ERR(qf_inode)) {
5726                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5727                 return PTR_ERR(qf_inode);
5728         }
5729 
5730         /* Don't account quota for quota files to avoid recursion */
5731         qf_inode->i_flags |= S_NOQUOTA;
5732         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5733         err = dquot_enable(qf_inode, type, format_id, flags);
5734         if (err)
5735                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5736         iput(qf_inode);
5737 
5738         return err;
5739 }
5740 
5741 /* Enable usage tracking for all quota types. */
5742 static int ext4_enable_quotas(struct super_block *sb)
5743 {
5744         int type, err = 0;
5745         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5746                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5747                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5748                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5749         };
5750         bool quota_mopt[EXT4_MAXQUOTAS] = {
5751                 test_opt(sb, USRQUOTA),
5752                 test_opt(sb, GRPQUOTA),
5753                 test_opt(sb, PRJQUOTA),
5754         };
5755 
5756         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5757         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5758                 if (qf_inums[type]) {
5759                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5760                                 DQUOT_USAGE_ENABLED |
5761                                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5762                         if (err) {
5763                                 ext4_warning(sb,
5764                                         "Failed to enable quota tracking "
5765                                         "(type=%d, err=%d). Please run "
5766                                         "e2fsck to fix.", type, err);
5767                                 for (type--; type >= 0; type--)
5768                                         dquot_quota_off(sb, type);
5769 
5770                                 return err;
5771                         }
5772                 }
5773         }
5774         return 0;
5775 }
5776 
5777 static int ext4_quota_off(struct super_block *sb, int type)
5778 {
5779         struct inode *inode = sb_dqopt(sb)->files[type];
5780         handle_t *handle;
5781         int err;
5782 
5783         /* Force all delayed allocation blocks to be allocated.
5784          * Caller already holds s_umount sem */
5785         if (test_opt(sb, DELALLOC))
5786                 sync_filesystem(sb);
5787 
5788         if (!inode || !igrab(inode))
5789                 goto out;
5790 
5791         err = dquot_quota_off(sb, type);
5792         if (err || ext4_has_feature_quota(sb))
5793                 goto out_put;
5794 
5795         inode_lock(inode);
5796         /*
5797          * Update modification times of quota files when userspace can
5798          * start looking at them. If we fail, we return success anyway since
5799          * this is not a hard failure and quotas are already disabled.
5800          */
5801         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5802         if (IS_ERR(handle))
5803                 goto out_unlock;
5804         EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5805         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5806         inode->i_mtime = inode->i_ctime = current_time(inode);
5807         ext4_mark_inode_dirty(handle, inode);
5808         ext4_journal_stop(handle);
5809 out_unlock:
5810         inode_unlock(inode);
5811 out_put:
5812         lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5813         iput(inode);
5814         return err;
5815 out:
5816         return dquot_quota_off(sb, type);
5817 }
5818 
5819 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5820  * acquiring the locks... As quota files are never truncated and quota code
5821  * itself serializes the operations (and no one else should touch the files)
5822  * we don't have to be afraid of races */
5823 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5824                                size_t len, loff_t off)
5825 {
5826         struct inode *inode = sb_dqopt(sb)->files[type];
5827         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5828         int offset = off & (sb->s_blocksize - 1);
5829         int tocopy;
5830         size_t toread;
5831         struct buffer_head *bh;
5832         loff_t i_size = i_size_read(inode);
5833 
5834         if (off > i_size)
5835                 return 0;
5836         if (off+len > i_size)
5837                 len = i_size-off;
5838         toread = len;
5839         while (toread > 0) {
5840                 tocopy = sb->s_blocksize - offset < toread ?
5841                                 sb->s_blocksize - offset : toread;
5842                 bh = ext4_bread(NULL, inode, blk, 0);
5843                 if (IS_ERR(bh))
5844                         return PTR_ERR(bh);
5845                 if (!bh)        /* A hole? */
5846                         memset(data, 0, tocopy);
5847                 else
5848                         memcpy(data, bh->b_data+offset, tocopy);
5849                 brelse(bh);
5850                 offset = 0;
5851                 toread -= tocopy;
5852                 data += tocopy;
5853                 blk++;
5854         }
5855         return len;
5856 }
5857 
5858 /* Write to quotafile (we know the transaction is already started and has
5859  * enough credits) */
5860 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5861                                 const char *data, size_t len, loff_t off)
5862 {
5863         struct inode *inode = sb_dqopt(sb)->files[type];
5864         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5865         int err, offset = off & (sb->s_blocksize - 1);
5866         int retries = 0;
5867         struct buffer_head *bh;
5868         handle_t *handle = journal_current_handle();
5869 
5870         if (EXT4_SB(sb)->s_journal && !handle) {
5871                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5872                         " cancelled because transaction is not started",
5873                         (unsigned long long)off, (unsigned long long)len);
5874                 return -EIO;
5875         }
5876         /*
5877          * Since we account only one data block in transaction credits,
5878          * then it is impossible to cross a block boundary.
5879          */
5880         if (sb->s_blocksize - offset < len) {
5881                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5882                         " cancelled because not block aligned",
5883                         (unsigned long long)off, (unsigned long long)len);
5884                 return -EIO;
5885         }
5886 
5887         do {
5888                 bh = ext4_bread(handle, inode, blk,
5889                                 EXT4_GET_BLOCKS_CREATE |
5890                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5891         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5892                  ext4_should_retry_alloc(inode->i_sb, &retries));
5893         if (IS_ERR(bh))
5894                 return PTR_ERR(bh);
5895         if (!bh)
5896                 goto out;
5897         BUFFER_TRACE(bh, "get write access");
5898         err = ext4_journal_get_write_access(handle, bh);
5899         if (err) {
5900                 brelse(bh);
5901                 return err;
5902         }
5903         lock_buffer(bh);
5904         memcpy(bh->b_data+offset, data, len);
5905         flush_dcache_page(bh->b_page);
5906         unlock_buffer(bh);
5907         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5908         brelse(bh);
5909 out:
5910         if (inode->i_size < off + len) {
5911                 i_size_write(inode, off + len);
5912                 EXT4_I(inode)->i_disksize = inode->i_size;
5913                 ext4_mark_inode_dirty(handle, inode);
5914         }
5915         return len;
5916 }
5917 
5918 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5919 {
5920         const struct quota_format_ops   *ops;
5921 
5922         if (!sb_has_quota_loaded(sb, qid->type))
5923                 return -ESRCH;
5924         ops = sb_dqopt(sb)->ops[qid->type];
5925         if (!ops || !ops->get_next_id)
5926                 return -ENOSYS;
5927         return dquot_get_next_id(sb, qid);
5928 }
5929 #endif
5930 
5931 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5932                        const char *dev_name, void *data)
5933 {
5934         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5935 }
5936 
5937 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5938 static inline void register_as_ext2(void)
5939 {
5940         int err = register_filesystem(&ext2_fs_type);
5941         if (err)
5942                 printk(KERN_WARNING
5943                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5944 }
5945 
5946 static inline void unregister_as_ext2(void)
5947 {
5948         unregister_filesystem(&ext2_fs_type);
5949 }
5950 
5951 static inline int ext2_feature_set_ok(struct super_block *sb)
5952 {
5953         if (ext4_has_unknown_ext2_incompat_features(sb))
5954                 return 0;
5955         if (sb_rdonly(sb))
5956                 return 1;
5957         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5958                 return 0;
5959         return 1;
5960 }
5961 #else
5962 static inline void register_as_ext2(void) { }
5963 static inline void unregister_as_ext2(void) { }
5964 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5965 #endif
5966 
5967 static inline void register_as_ext3(void)
5968 {
5969         int err = register_filesystem(&ext3_fs_type);
5970         if (err)
5971                 printk(KERN_WARNING
5972                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5973 }
5974 
5975 static inline void unregister_as_ext3(void)
5976 {
5977         unregister_filesystem(&ext3_fs_type);
5978 }
5979 
5980 static inline int ext3_feature_set_ok(struct super_block *sb)
5981 {
5982         if (ext4_has_unknown_ext3_incompat_features(sb))
5983                 return 0;
5984         if (!ext4_has_feature_journal(sb))
5985                 return 0;
5986         if (sb_rdonly(sb))
5987                 return 1;
5988         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5989                 return 0;
5990         return 1;
5991 }
5992 
5993 static struct file_system_type ext4_fs_type = {
5994         .owner          = THIS_MODULE,
5995         .name           = "ext4",
5996         .mount          = ext4_mount,
5997         .kill_sb        = kill_block_super,
5998         .fs_flags       = FS_REQUIRES_DEV,
5999 };
6000 MODULE_ALIAS_FS("ext4");
6001 
6002 /* Shared across all ext4 file systems */
6003 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6004 
6005 static int __init ext4_init_fs(void)
6006 {
6007         int i, err;
6008 
6009         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6010         ext4_li_info = NULL;
6011         mutex_init(&ext4_li_mtx);
6012 
6013         /* Build-time check for flags consistency */
6014         ext4_check_flag_values();
6015 
6016         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6017                 init_waitqueue_head(&ext4__ioend_wq[i]);
6018 
6019         err = ext4_init_es();
6020         if (err)
6021                 return err;
6022 
6023         err = ext4_init_pending();
6024         if (err)
6025                 goto out6;
6026 
6027         err = ext4_init_pageio();
6028         if (err)
6029                 goto out5;
6030 
6031         err = ext4_init_system_zone();
6032         if (err)
6033                 goto out4;
6034 
6035         err = ext4_init_sysfs();
6036         if (err)
6037                 goto out3;
6038 
6039         err = ext4_init_mballoc();
6040         if (err)
6041                 goto out2;
6042         err = init_inodecache();
6043         if (err)
6044                 goto out1;
6045         register_as_ext3();
6046         register_as_ext2();
6047         err = register_filesystem(&ext4_fs_type);
6048         if (err)
6049                 goto out;
6050 
6051         return 0;
6052 out:
6053         unregister_as_ext2();
6054         unregister_as_ext3();
6055         destroy_inodecache();
6056 out1:
6057         ext4_exit_mballoc();
6058 out2:
6059         ext4_exit_sysfs();
6060 out3:
6061         ext4_exit_system_zone();
6062 out4:
6063         ext4_exit_pageio();
6064 out5:
6065         ext4_exit_pending();
6066 out6:
6067         ext4_exit_es();
6068 
6069         return err;
6070 }
6071 
6072 static void __exit ext4_exit_fs(void)
6073 {
6074         ext4_destroy_lazyinit_thread();
6075         unregister_as_ext2();
6076         unregister_as_ext3();
6077         unregister_filesystem(&ext4_fs_type);
6078         destroy_inodecache();
6079         ext4_exit_mballoc();
6080         ext4_exit_sysfs();
6081         ext4_exit_system_zone();
6082         ext4_exit_pageio();
6083         ext4_exit_es();
6084         ext4_exit_pending();
6085 }
6086 
6087 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6088 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6089 MODULE_LICENSE("GPL");
6090 MODULE_SOFTDEP("pre: crc32c");
6091 module_init(ext4_init_fs)
6092 module_exit(ext4_exit_fs)
6093 

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