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TOMOYO Linux Cross Reference
Linux/fs/ext4/super.c

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  1 /*
  2  *  linux/fs/ext4/super.c
  3  *
  4  * Copyright (C) 1992, 1993, 1994, 1995
  5  * Remy Card (card@masi.ibp.fr)
  6  * Laboratoire MASI - Institut Blaise Pascal
  7  * Universite Pierre et Marie Curie (Paris VI)
  8  *
  9  *  from
 10  *
 11  *  linux/fs/minix/inode.c
 12  *
 13  *  Copyright (C) 1991, 1992  Linus Torvalds
 14  *
 15  *  Big-endian to little-endian byte-swapping/bitmaps by
 16  *        David S. Miller (davem@caip.rutgers.edu), 1995
 17  */
 18 
 19 #include <linux/module.h>
 20 #include <linux/string.h>
 21 #include <linux/fs.h>
 22 #include <linux/time.h>
 23 #include <linux/vmalloc.h>
 24 #include <linux/slab.h>
 25 #include <linux/init.h>
 26 #include <linux/blkdev.h>
 27 #include <linux/backing-dev.h>
 28 #include <linux/parser.h>
 29 #include <linux/buffer_head.h>
 30 #include <linux/exportfs.h>
 31 #include <linux/vfs.h>
 32 #include <linux/random.h>
 33 #include <linux/mount.h>
 34 #include <linux/namei.h>
 35 #include <linux/quotaops.h>
 36 #include <linux/seq_file.h>
 37 #include <linux/ctype.h>
 38 #include <linux/log2.h>
 39 #include <linux/crc16.h>
 40 #include <linux/dax.h>
 41 #include <linux/cleancache.h>
 42 #include <linux/uaccess.h>
 43 
 44 #include <linux/kthread.h>
 45 #include <linux/freezer.h>
 46 
 47 #include "ext4.h"
 48 #include "ext4_extents.h"       /* Needed for trace points definition */
 49 #include "ext4_jbd2.h"
 50 #include "xattr.h"
 51 #include "acl.h"
 52 #include "mballoc.h"
 53 #include "fsmap.h"
 54 
 55 #define CREATE_TRACE_POINTS
 56 #include <trace/events/ext4.h>
 57 
 58 static struct ext4_lazy_init *ext4_li_info;
 59 static struct mutex ext4_li_mtx;
 60 static struct ratelimit_state ext4_mount_msg_ratelimit;
 61 
 62 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
 63                              unsigned long journal_devnum);
 64 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
 65 static int ext4_commit_super(struct super_block *sb, int sync);
 66 static void ext4_mark_recovery_complete(struct super_block *sb,
 67                                         struct ext4_super_block *es);
 68 static void ext4_clear_journal_err(struct super_block *sb,
 69                                    struct ext4_super_block *es);
 70 static int ext4_sync_fs(struct super_block *sb, int wait);
 71 static int ext4_remount(struct super_block *sb, int *flags, char *data);
 72 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
 73 static int ext4_unfreeze(struct super_block *sb);
 74 static int ext4_freeze(struct super_block *sb);
 75 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
 76                        const char *dev_name, void *data);
 77 static inline int ext2_feature_set_ok(struct super_block *sb);
 78 static inline int ext3_feature_set_ok(struct super_block *sb);
 79 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
 80 static void ext4_destroy_lazyinit_thread(void);
 81 static void ext4_unregister_li_request(struct super_block *sb);
 82 static void ext4_clear_request_list(void);
 83 static struct inode *ext4_get_journal_inode(struct super_block *sb,
 84                                             unsigned int journal_inum);
 85 
 86 /*
 87  * Lock ordering
 88  *
 89  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
 90  * i_mmap_rwsem (inode->i_mmap_rwsem)!
 91  *
 92  * page fault path:
 93  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
 94  *   page lock -> i_data_sem (rw)
 95  *
 96  * buffered write path:
 97  * sb_start_write -> i_mutex -> mmap_sem
 98  * sb_start_write -> i_mutex -> transaction start -> page lock ->
 99  *   i_data_sem (rw)
100  *
101  * truncate:
102  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
103  *   i_mmap_rwsem (w) -> page lock
104  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
105  *   transaction start -> i_data_sem (rw)
106  *
107  * direct IO:
108  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
109  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
110  *   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 static int ext4_verify_csum_type(struct super_block *sb,
144                                  struct ext4_super_block *es)
145 {
146         if (!ext4_has_feature_metadata_csum(sb))
147                 return 1;
148 
149         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
150 }
151 
152 static __le32 ext4_superblock_csum(struct super_block *sb,
153                                    struct ext4_super_block *es)
154 {
155         struct ext4_sb_info *sbi = EXT4_SB(sb);
156         int offset = offsetof(struct ext4_super_block, s_checksum);
157         __u32 csum;
158 
159         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
160 
161         return cpu_to_le32(csum);
162 }
163 
164 static int ext4_superblock_csum_verify(struct super_block *sb,
165                                        struct ext4_super_block *es)
166 {
167         if (!ext4_has_metadata_csum(sb))
168                 return 1;
169 
170         return es->s_checksum == ext4_superblock_csum(sb, es);
171 }
172 
173 void ext4_superblock_csum_set(struct super_block *sb)
174 {
175         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
176 
177         if (!ext4_has_metadata_csum(sb))
178                 return;
179 
180         es->s_checksum = ext4_superblock_csum(sb, es);
181 }
182 
183 void *ext4_kvmalloc(size_t size, gfp_t flags)
184 {
185         void *ret;
186 
187         ret = kmalloc(size, flags | __GFP_NOWARN);
188         if (!ret)
189                 ret = __vmalloc(size, flags, PAGE_KERNEL);
190         return ret;
191 }
192 
193 void *ext4_kvzalloc(size_t size, gfp_t flags)
194 {
195         void *ret;
196 
197         ret = kzalloc(size, flags | __GFP_NOWARN);
198         if (!ret)
199                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
200         return ret;
201 }
202 
203 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
204                                struct ext4_group_desc *bg)
205 {
206         return le32_to_cpu(bg->bg_block_bitmap_lo) |
207                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
208                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
209 }
210 
211 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
212                                struct ext4_group_desc *bg)
213 {
214         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
215                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
216                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
217 }
218 
219 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
220                               struct ext4_group_desc *bg)
221 {
222         return le32_to_cpu(bg->bg_inode_table_lo) |
223                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
224                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
225 }
226 
227 __u32 ext4_free_group_clusters(struct super_block *sb,
228                                struct ext4_group_desc *bg)
229 {
230         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
231                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
232                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
233 }
234 
235 __u32 ext4_free_inodes_count(struct super_block *sb,
236                               struct ext4_group_desc *bg)
237 {
238         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
239                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
240                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
241 }
242 
243 __u32 ext4_used_dirs_count(struct super_block *sb,
244                               struct ext4_group_desc *bg)
245 {
246         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
247                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
248                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
249 }
250 
251 __u32 ext4_itable_unused_count(struct super_block *sb,
252                               struct ext4_group_desc *bg)
253 {
254         return le16_to_cpu(bg->bg_itable_unused_lo) |
255                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
256                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
257 }
258 
259 void ext4_block_bitmap_set(struct super_block *sb,
260                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
261 {
262         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
263         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
264                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
265 }
266 
267 void ext4_inode_bitmap_set(struct super_block *sb,
268                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
269 {
270         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
271         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
272                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
273 }
274 
275 void ext4_inode_table_set(struct super_block *sb,
276                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
277 {
278         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
279         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
280                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
281 }
282 
283 void ext4_free_group_clusters_set(struct super_block *sb,
284                                   struct ext4_group_desc *bg, __u32 count)
285 {
286         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
287         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
288                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
289 }
290 
291 void ext4_free_inodes_set(struct super_block *sb,
292                           struct ext4_group_desc *bg, __u32 count)
293 {
294         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
295         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
296                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
297 }
298 
299 void ext4_used_dirs_set(struct super_block *sb,
300                           struct ext4_group_desc *bg, __u32 count)
301 {
302         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
303         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
304                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
305 }
306 
307 void ext4_itable_unused_set(struct super_block *sb,
308                           struct ext4_group_desc *bg, __u32 count)
309 {
310         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
311         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
312                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
313 }
314 
315 
316 static void __save_error_info(struct super_block *sb, const char *func,
317                             unsigned int line)
318 {
319         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
320 
321         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
322         if (bdev_read_only(sb->s_bdev))
323                 return;
324         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
325         es->s_last_error_time = cpu_to_le32(get_seconds());
326         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
327         es->s_last_error_line = cpu_to_le32(line);
328         if (!es->s_first_error_time) {
329                 es->s_first_error_time = es->s_last_error_time;
330                 strncpy(es->s_first_error_func, func,
331                         sizeof(es->s_first_error_func));
332                 es->s_first_error_line = cpu_to_le32(line);
333                 es->s_first_error_ino = es->s_last_error_ino;
334                 es->s_first_error_block = es->s_last_error_block;
335         }
336         /*
337          * Start the daily error reporting function if it hasn't been
338          * started already
339          */
340         if (!es->s_error_count)
341                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
342         le32_add_cpu(&es->s_error_count, 1);
343 }
344 
345 static void save_error_info(struct super_block *sb, const char *func,
346                             unsigned int line)
347 {
348         __save_error_info(sb, func, line);
349         ext4_commit_super(sb, 1);
350 }
351 
352 /*
353  * The del_gendisk() function uninitializes the disk-specific data
354  * structures, including the bdi structure, without telling anyone
355  * else.  Once this happens, any attempt to call mark_buffer_dirty()
356  * (for example, by ext4_commit_super), will cause a kernel OOPS.
357  * This is a kludge to prevent these oops until we can put in a proper
358  * hook in del_gendisk() to inform the VFS and file system layers.
359  */
360 static int block_device_ejected(struct super_block *sb)
361 {
362         struct inode *bd_inode = sb->s_bdev->bd_inode;
363         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
364 
365         return bdi->dev == NULL;
366 }
367 
368 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
369 {
370         struct super_block              *sb = journal->j_private;
371         struct ext4_sb_info             *sbi = EXT4_SB(sb);
372         int                             error = is_journal_aborted(journal);
373         struct ext4_journal_cb_entry    *jce;
374 
375         BUG_ON(txn->t_state == T_FINISHED);
376 
377         ext4_process_freed_data(sb, txn->t_tid);
378 
379         spin_lock(&sbi->s_md_lock);
380         while (!list_empty(&txn->t_private_list)) {
381                 jce = list_entry(txn->t_private_list.next,
382                                  struct ext4_journal_cb_entry, jce_list);
383                 list_del_init(&jce->jce_list);
384                 spin_unlock(&sbi->s_md_lock);
385                 jce->jce_func(sb, jce, error);
386                 spin_lock(&sbi->s_md_lock);
387         }
388         spin_unlock(&sbi->s_md_lock);
389 }
390 
391 /* Deal with the reporting of failure conditions on a filesystem such as
392  * inconsistencies detected or read IO failures.
393  *
394  * On ext2, we can store the error state of the filesystem in the
395  * superblock.  That is not possible on ext4, because we may have other
396  * write ordering constraints on the superblock which prevent us from
397  * writing it out straight away; and given that the journal is about to
398  * be aborted, we can't rely on the current, or future, transactions to
399  * write out the superblock safely.
400  *
401  * We'll just use the jbd2_journal_abort() error code to record an error in
402  * the journal instead.  On recovery, the journal will complain about
403  * that error until we've noted it down and cleared it.
404  */
405 
406 static void ext4_handle_error(struct super_block *sb)
407 {
408         if (sb_rdonly(sb))
409                 return;
410 
411         if (!test_opt(sb, ERRORS_CONT)) {
412                 journal_t *journal = EXT4_SB(sb)->s_journal;
413 
414                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
415                 if (journal)
416                         jbd2_journal_abort(journal, -EIO);
417         }
418         if (test_opt(sb, ERRORS_RO)) {
419                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
420                 /*
421                  * Make sure updated value of ->s_mount_flags will be visible
422                  * before ->s_flags update
423                  */
424                 smp_wmb();
425                 sb->s_flags |= SB_RDONLY;
426         }
427         if (test_opt(sb, ERRORS_PANIC)) {
428                 if (EXT4_SB(sb)->s_journal &&
429                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
430                         return;
431                 panic("EXT4-fs (device %s): panic forced after error\n",
432                         sb->s_id);
433         }
434 }
435 
436 #define ext4_error_ratelimit(sb)                                        \
437                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
438                              "EXT4-fs error")
439 
440 void __ext4_error(struct super_block *sb, const char *function,
441                   unsigned int line, const char *fmt, ...)
442 {
443         struct va_format vaf;
444         va_list args;
445 
446         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
447                 return;
448 
449         if (ext4_error_ratelimit(sb)) {
450                 va_start(args, fmt);
451                 vaf.fmt = fmt;
452                 vaf.va = &args;
453                 printk(KERN_CRIT
454                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
455                        sb->s_id, function, line, current->comm, &vaf);
456                 va_end(args);
457         }
458         save_error_info(sb, function, line);
459         ext4_handle_error(sb);
460 }
461 
462 void __ext4_error_inode(struct inode *inode, const char *function,
463                         unsigned int line, ext4_fsblk_t block,
464                         const char *fmt, ...)
465 {
466         va_list args;
467         struct va_format vaf;
468         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
469 
470         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
471                 return;
472 
473         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
474         es->s_last_error_block = cpu_to_le64(block);
475         if (ext4_error_ratelimit(inode->i_sb)) {
476                 va_start(args, fmt);
477                 vaf.fmt = fmt;
478                 vaf.va = &args;
479                 if (block)
480                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
481                                "inode #%lu: block %llu: comm %s: %pV\n",
482                                inode->i_sb->s_id, function, line, inode->i_ino,
483                                block, current->comm, &vaf);
484                 else
485                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
486                                "inode #%lu: comm %s: %pV\n",
487                                inode->i_sb->s_id, function, line, inode->i_ino,
488                                current->comm, &vaf);
489                 va_end(args);
490         }
491         save_error_info(inode->i_sb, function, line);
492         ext4_handle_error(inode->i_sb);
493 }
494 
495 void __ext4_error_file(struct file *file, const char *function,
496                        unsigned int line, ext4_fsblk_t block,
497                        const char *fmt, ...)
498 {
499         va_list args;
500         struct va_format vaf;
501         struct ext4_super_block *es;
502         struct inode *inode = file_inode(file);
503         char pathname[80], *path;
504 
505         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
506                 return;
507 
508         es = EXT4_SB(inode->i_sb)->s_es;
509         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
510         if (ext4_error_ratelimit(inode->i_sb)) {
511                 path = file_path(file, pathname, sizeof(pathname));
512                 if (IS_ERR(path))
513                         path = "(unknown)";
514                 va_start(args, fmt);
515                 vaf.fmt = fmt;
516                 vaf.va = &args;
517                 if (block)
518                         printk(KERN_CRIT
519                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
520                                "block %llu: comm %s: path %s: %pV\n",
521                                inode->i_sb->s_id, function, line, inode->i_ino,
522                                block, current->comm, path, &vaf);
523                 else
524                         printk(KERN_CRIT
525                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
526                                "comm %s: path %s: %pV\n",
527                                inode->i_sb->s_id, function, line, inode->i_ino,
528                                current->comm, path, &vaf);
529                 va_end(args);
530         }
531         save_error_info(inode->i_sb, function, line);
532         ext4_handle_error(inode->i_sb);
533 }
534 
535 const char *ext4_decode_error(struct super_block *sb, int errno,
536                               char nbuf[16])
537 {
538         char *errstr = NULL;
539 
540         switch (errno) {
541         case -EFSCORRUPTED:
542                 errstr = "Corrupt filesystem";
543                 break;
544         case -EFSBADCRC:
545                 errstr = "Filesystem failed CRC";
546                 break;
547         case -EIO:
548                 errstr = "IO failure";
549                 break;
550         case -ENOMEM:
551                 errstr = "Out of memory";
552                 break;
553         case -EROFS:
554                 if (!sb || (EXT4_SB(sb)->s_journal &&
555                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
556                         errstr = "Journal has aborted";
557                 else
558                         errstr = "Readonly filesystem";
559                 break;
560         default:
561                 /* If the caller passed in an extra buffer for unknown
562                  * errors, textualise them now.  Else we just return
563                  * NULL. */
564                 if (nbuf) {
565                         /* Check for truncated error codes... */
566                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
567                                 errstr = nbuf;
568                 }
569                 break;
570         }
571 
572         return errstr;
573 }
574 
575 /* __ext4_std_error decodes expected errors from journaling functions
576  * automatically and invokes the appropriate error response.  */
577 
578 void __ext4_std_error(struct super_block *sb, const char *function,
579                       unsigned int line, int errno)
580 {
581         char nbuf[16];
582         const char *errstr;
583 
584         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
585                 return;
586 
587         /* Special case: if the error is EROFS, and we're not already
588          * inside a transaction, then there's really no point in logging
589          * an error. */
590         if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
591                 return;
592 
593         if (ext4_error_ratelimit(sb)) {
594                 errstr = ext4_decode_error(sb, errno, nbuf);
595                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
596                        sb->s_id, function, line, errstr);
597         }
598 
599         save_error_info(sb, function, line);
600         ext4_handle_error(sb);
601 }
602 
603 /*
604  * ext4_abort is a much stronger failure handler than ext4_error.  The
605  * abort function may be used to deal with unrecoverable failures such
606  * as journal IO errors or ENOMEM at a critical moment in log management.
607  *
608  * We unconditionally force the filesystem into an ABORT|READONLY state,
609  * unless the error response on the fs has been set to panic in which
610  * case we take the easy way out and panic immediately.
611  */
612 
613 void __ext4_abort(struct super_block *sb, const char *function,
614                 unsigned int line, const char *fmt, ...)
615 {
616         struct va_format vaf;
617         va_list args;
618 
619         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
620                 return;
621 
622         save_error_info(sb, function, line);
623         va_start(args, fmt);
624         vaf.fmt = fmt;
625         vaf.va = &args;
626         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
627                sb->s_id, function, line, &vaf);
628         va_end(args);
629 
630         if (sb_rdonly(sb) == 0) {
631                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
632                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
633                 /*
634                  * Make sure updated value of ->s_mount_flags will be visible
635                  * before ->s_flags update
636                  */
637                 smp_wmb();
638                 sb->s_flags |= SB_RDONLY;
639                 if (EXT4_SB(sb)->s_journal)
640                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
641                 save_error_info(sb, function, line);
642         }
643         if (test_opt(sb, ERRORS_PANIC)) {
644                 if (EXT4_SB(sb)->s_journal &&
645                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
646                         return;
647                 panic("EXT4-fs panic from previous error\n");
648         }
649 }
650 
651 void __ext4_msg(struct super_block *sb,
652                 const char *prefix, const char *fmt, ...)
653 {
654         struct va_format vaf;
655         va_list args;
656 
657         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
658                 return;
659 
660         va_start(args, fmt);
661         vaf.fmt = fmt;
662         vaf.va = &args;
663         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
664         va_end(args);
665 }
666 
667 #define ext4_warning_ratelimit(sb)                                      \
668                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
669                              "EXT4-fs warning")
670 
671 void __ext4_warning(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 (!ext4_warning_ratelimit(sb))
678                 return;
679 
680         va_start(args, fmt);
681         vaf.fmt = fmt;
682         vaf.va = &args;
683         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
684                sb->s_id, function, line, &vaf);
685         va_end(args);
686 }
687 
688 void __ext4_warning_inode(const struct inode *inode, const char *function,
689                           unsigned int line, const char *fmt, ...)
690 {
691         struct va_format vaf;
692         va_list args;
693 
694         if (!ext4_warning_ratelimit(inode->i_sb))
695                 return;
696 
697         va_start(args, fmt);
698         vaf.fmt = fmt;
699         vaf.va = &args;
700         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
701                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
702                function, line, inode->i_ino, current->comm, &vaf);
703         va_end(args);
704 }
705 
706 void __ext4_grp_locked_error(const char *function, unsigned int line,
707                              struct super_block *sb, ext4_group_t grp,
708                              unsigned long ino, ext4_fsblk_t block,
709                              const char *fmt, ...)
710 __releases(bitlock)
711 __acquires(bitlock)
712 {
713         struct va_format vaf;
714         va_list args;
715         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
716 
717         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
718                 return;
719 
720         es->s_last_error_ino = cpu_to_le32(ino);
721         es->s_last_error_block = cpu_to_le64(block);
722         __save_error_info(sb, function, line);
723 
724         if (ext4_error_ratelimit(sb)) {
725                 va_start(args, fmt);
726                 vaf.fmt = fmt;
727                 vaf.va = &args;
728                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
729                        sb->s_id, function, line, grp);
730                 if (ino)
731                         printk(KERN_CONT "inode %lu: ", ino);
732                 if (block)
733                         printk(KERN_CONT "block %llu:",
734                                (unsigned long long) block);
735                 printk(KERN_CONT "%pV\n", &vaf);
736                 va_end(args);
737         }
738 
739         if (test_opt(sb, ERRORS_CONT)) {
740                 ext4_commit_super(sb, 0);
741                 return;
742         }
743 
744         ext4_unlock_group(sb, grp);
745         ext4_commit_super(sb, 1);
746         ext4_handle_error(sb);
747         /*
748          * We only get here in the ERRORS_RO case; relocking the group
749          * may be dangerous, but nothing bad will happen since the
750          * filesystem will have already been marked read/only and the
751          * journal has been aborted.  We return 1 as a hint to callers
752          * who might what to use the return value from
753          * ext4_grp_locked_error() to distinguish between the
754          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
755          * aggressively from the ext4 function in question, with a
756          * more appropriate error code.
757          */
758         ext4_lock_group(sb, grp);
759         return;
760 }
761 
762 void ext4_update_dynamic_rev(struct super_block *sb)
763 {
764         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
765 
766         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
767                 return;
768 
769         ext4_warning(sb,
770                      "updating to rev %d because of new feature flag, "
771                      "running e2fsck is recommended",
772                      EXT4_DYNAMIC_REV);
773 
774         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
775         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
776         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
777         /* leave es->s_feature_*compat flags alone */
778         /* es->s_uuid will be set by e2fsck if empty */
779 
780         /*
781          * The rest of the superblock fields should be zero, and if not it
782          * means they are likely already in use, so leave them alone.  We
783          * can leave it up to e2fsck to clean up any inconsistencies there.
784          */
785 }
786 
787 /*
788  * Open the external journal device
789  */
790 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
791 {
792         struct block_device *bdev;
793         char b[BDEVNAME_SIZE];
794 
795         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
796         if (IS_ERR(bdev))
797                 goto fail;
798         return bdev;
799 
800 fail:
801         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
802                         __bdevname(dev, b), PTR_ERR(bdev));
803         return NULL;
804 }
805 
806 /*
807  * Release the journal device
808  */
809 static void ext4_blkdev_put(struct block_device *bdev)
810 {
811         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
812 }
813 
814 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
815 {
816         struct block_device *bdev;
817         bdev = sbi->journal_bdev;
818         if (bdev) {
819                 ext4_blkdev_put(bdev);
820                 sbi->journal_bdev = NULL;
821         }
822 }
823 
824 static inline struct inode *orphan_list_entry(struct list_head *l)
825 {
826         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
827 }
828 
829 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
830 {
831         struct list_head *l;
832 
833         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
834                  le32_to_cpu(sbi->s_es->s_last_orphan));
835 
836         printk(KERN_ERR "sb_info orphan list:\n");
837         list_for_each(l, &sbi->s_orphan) {
838                 struct inode *inode = orphan_list_entry(l);
839                 printk(KERN_ERR "  "
840                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
841                        inode->i_sb->s_id, inode->i_ino, inode,
842                        inode->i_mode, inode->i_nlink,
843                        NEXT_ORPHAN(inode));
844         }
845 }
846 
847 #ifdef CONFIG_QUOTA
848 static int ext4_quota_off(struct super_block *sb, int type);
849 
850 static inline void ext4_quota_off_umount(struct super_block *sb)
851 {
852         int type;
853 
854         /* Use our quota_off function to clear inode flags etc. */
855         for (type = 0; type < EXT4_MAXQUOTAS; type++)
856                 ext4_quota_off(sb, type);
857 }
858 #else
859 static inline void ext4_quota_off_umount(struct super_block *sb)
860 {
861 }
862 #endif
863 
864 static void ext4_put_super(struct super_block *sb)
865 {
866         struct ext4_sb_info *sbi = EXT4_SB(sb);
867         struct ext4_super_block *es = sbi->s_es;
868         int aborted = 0;
869         int i, err;
870 
871         ext4_unregister_li_request(sb);
872         ext4_quota_off_umount(sb);
873 
874         flush_workqueue(sbi->rsv_conversion_wq);
875         destroy_workqueue(sbi->rsv_conversion_wq);
876 
877         if (sbi->s_journal) {
878                 aborted = is_journal_aborted(sbi->s_journal);
879                 err = jbd2_journal_destroy(sbi->s_journal);
880                 sbi->s_journal = NULL;
881                 if ((err < 0) && !aborted)
882                         ext4_abort(sb, "Couldn't clean up the journal");
883         }
884 
885         ext4_unregister_sysfs(sb);
886         ext4_es_unregister_shrinker(sbi);
887         del_timer_sync(&sbi->s_err_report);
888         ext4_release_system_zone(sb);
889         ext4_mb_release(sb);
890         ext4_ext_release(sb);
891 
892         if (!sb_rdonly(sb) && !aborted) {
893                 ext4_clear_feature_journal_needs_recovery(sb);
894                 es->s_state = cpu_to_le16(sbi->s_mount_state);
895         }
896         if (!sb_rdonly(sb))
897                 ext4_commit_super(sb, 1);
898 
899         for (i = 0; i < sbi->s_gdb_count; i++)
900                 brelse(sbi->s_group_desc[i]);
901         kvfree(sbi->s_group_desc);
902         kvfree(sbi->s_flex_groups);
903         percpu_counter_destroy(&sbi->s_freeclusters_counter);
904         percpu_counter_destroy(&sbi->s_freeinodes_counter);
905         percpu_counter_destroy(&sbi->s_dirs_counter);
906         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
907         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
908 #ifdef CONFIG_QUOTA
909         for (i = 0; i < EXT4_MAXQUOTAS; i++)
910                 kfree(sbi->s_qf_names[i]);
911 #endif
912 
913         /* Debugging code just in case the in-memory inode orphan list
914          * isn't empty.  The on-disk one can be non-empty if we've
915          * detected an error and taken the fs readonly, but the
916          * in-memory list had better be clean by this point. */
917         if (!list_empty(&sbi->s_orphan))
918                 dump_orphan_list(sb, sbi);
919         J_ASSERT(list_empty(&sbi->s_orphan));
920 
921         sync_blockdev(sb->s_bdev);
922         invalidate_bdev(sb->s_bdev);
923         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
924                 /*
925                  * Invalidate the journal device's buffers.  We don't want them
926                  * floating about in memory - the physical journal device may
927                  * hotswapped, and it breaks the `ro-after' testing code.
928                  */
929                 sync_blockdev(sbi->journal_bdev);
930                 invalidate_bdev(sbi->journal_bdev);
931                 ext4_blkdev_remove(sbi);
932         }
933         if (sbi->s_ea_inode_cache) {
934                 ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
935                 sbi->s_ea_inode_cache = NULL;
936         }
937         if (sbi->s_ea_block_cache) {
938                 ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
939                 sbi->s_ea_block_cache = NULL;
940         }
941         if (sbi->s_mmp_tsk)
942                 kthread_stop(sbi->s_mmp_tsk);
943         brelse(sbi->s_sbh);
944         sb->s_fs_info = NULL;
945         /*
946          * Now that we are completely done shutting down the
947          * superblock, we need to actually destroy the kobject.
948          */
949         kobject_put(&sbi->s_kobj);
950         wait_for_completion(&sbi->s_kobj_unregister);
951         if (sbi->s_chksum_driver)
952                 crypto_free_shash(sbi->s_chksum_driver);
953         kfree(sbi->s_blockgroup_lock);
954         fs_put_dax(sbi->s_daxdev);
955         kfree(sbi);
956 }
957 
958 static struct kmem_cache *ext4_inode_cachep;
959 
960 /*
961  * Called inside transaction, so use GFP_NOFS
962  */
963 static struct inode *ext4_alloc_inode(struct super_block *sb)
964 {
965         struct ext4_inode_info *ei;
966 
967         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
968         if (!ei)
969                 return NULL;
970 
971         ei->vfs_inode.i_version = 1;
972         spin_lock_init(&ei->i_raw_lock);
973         INIT_LIST_HEAD(&ei->i_prealloc_list);
974         spin_lock_init(&ei->i_prealloc_lock);
975         ext4_es_init_tree(&ei->i_es_tree);
976         rwlock_init(&ei->i_es_lock);
977         INIT_LIST_HEAD(&ei->i_es_list);
978         ei->i_es_all_nr = 0;
979         ei->i_es_shk_nr = 0;
980         ei->i_es_shrink_lblk = 0;
981         ei->i_reserved_data_blocks = 0;
982         ei->i_da_metadata_calc_len = 0;
983         ei->i_da_metadata_calc_last_lblock = 0;
984         spin_lock_init(&(ei->i_block_reservation_lock));
985 #ifdef CONFIG_QUOTA
986         ei->i_reserved_quota = 0;
987         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
988 #endif
989         ei->jinode = NULL;
990         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
991         spin_lock_init(&ei->i_completed_io_lock);
992         ei->i_sync_tid = 0;
993         ei->i_datasync_tid = 0;
994         atomic_set(&ei->i_unwritten, 0);
995         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
996         return &ei->vfs_inode;
997 }
998 
999 static int ext4_drop_inode(struct inode *inode)
1000 {
1001         int drop = generic_drop_inode(inode);
1002 
1003         trace_ext4_drop_inode(inode, drop);
1004         return drop;
1005 }
1006 
1007 static void ext4_i_callback(struct rcu_head *head)
1008 {
1009         struct inode *inode = container_of(head, struct inode, i_rcu);
1010         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1011 }
1012 
1013 static void ext4_destroy_inode(struct inode *inode)
1014 {
1015         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1016                 ext4_msg(inode->i_sb, KERN_ERR,
1017                          "Inode %lu (%p): orphan list check failed!",
1018                          inode->i_ino, EXT4_I(inode));
1019                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1020                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
1021                                 true);
1022                 dump_stack();
1023         }
1024         call_rcu(&inode->i_rcu, ext4_i_callback);
1025 }
1026 
1027 static void init_once(void *foo)
1028 {
1029         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1030 
1031         INIT_LIST_HEAD(&ei->i_orphan);
1032         init_rwsem(&ei->xattr_sem);
1033         init_rwsem(&ei->i_data_sem);
1034         init_rwsem(&ei->i_mmap_sem);
1035         inode_init_once(&ei->vfs_inode);
1036 }
1037 
1038 static int __init init_inodecache(void)
1039 {
1040         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1041                                              sizeof(struct ext4_inode_info),
1042                                              0, (SLAB_RECLAIM_ACCOUNT|
1043                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1044                                              init_once);
1045         if (ext4_inode_cachep == NULL)
1046                 return -ENOMEM;
1047         return 0;
1048 }
1049 
1050 static void destroy_inodecache(void)
1051 {
1052         /*
1053          * Make sure all delayed rcu free inodes are flushed before we
1054          * destroy cache.
1055          */
1056         rcu_barrier();
1057         kmem_cache_destroy(ext4_inode_cachep);
1058 }
1059 
1060 void ext4_clear_inode(struct inode *inode)
1061 {
1062         invalidate_inode_buffers(inode);
1063         clear_inode(inode);
1064         dquot_drop(inode);
1065         ext4_discard_preallocations(inode);
1066         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1067         if (EXT4_I(inode)->jinode) {
1068                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1069                                                EXT4_I(inode)->jinode);
1070                 jbd2_free_inode(EXT4_I(inode)->jinode);
1071                 EXT4_I(inode)->jinode = NULL;
1072         }
1073 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1074         fscrypt_put_encryption_info(inode, NULL);
1075 #endif
1076 }
1077 
1078 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1079                                         u64 ino, u32 generation)
1080 {
1081         struct inode *inode;
1082 
1083         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1084                 return ERR_PTR(-ESTALE);
1085         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1086                 return ERR_PTR(-ESTALE);
1087 
1088         /* iget isn't really right if the inode is currently unallocated!!
1089          *
1090          * ext4_read_inode will return a bad_inode if the inode had been
1091          * deleted, so we should be safe.
1092          *
1093          * Currently we don't know the generation for parent directory, so
1094          * a generation of 0 means "accept any"
1095          */
1096         inode = ext4_iget_normal(sb, ino);
1097         if (IS_ERR(inode))
1098                 return ERR_CAST(inode);
1099         if (generation && inode->i_generation != generation) {
1100                 iput(inode);
1101                 return ERR_PTR(-ESTALE);
1102         }
1103 
1104         return inode;
1105 }
1106 
1107 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1108                                         int fh_len, int fh_type)
1109 {
1110         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1111                                     ext4_nfs_get_inode);
1112 }
1113 
1114 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1115                                         int fh_len, int fh_type)
1116 {
1117         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1118                                     ext4_nfs_get_inode);
1119 }
1120 
1121 /*
1122  * Try to release metadata pages (indirect blocks, directories) which are
1123  * mapped via the block device.  Since these pages could have journal heads
1124  * which would prevent try_to_free_buffers() from freeing them, we must use
1125  * jbd2 layer's try_to_free_buffers() function to release them.
1126  */
1127 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1128                                  gfp_t wait)
1129 {
1130         journal_t *journal = EXT4_SB(sb)->s_journal;
1131 
1132         WARN_ON(PageChecked(page));
1133         if (!page_has_buffers(page))
1134                 return 0;
1135         if (journal)
1136                 return jbd2_journal_try_to_free_buffers(journal, page,
1137                                                 wait & ~__GFP_DIRECT_RECLAIM);
1138         return try_to_free_buffers(page);
1139 }
1140 
1141 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1142 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1143 {
1144         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1145                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1146 }
1147 
1148 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1149                                                         void *fs_data)
1150 {
1151         handle_t *handle = fs_data;
1152         int res, res2, credits, retries = 0;
1153 
1154         /*
1155          * Encrypting the root directory is not allowed because e2fsck expects
1156          * lost+found to exist and be unencrypted, and encrypting the root
1157          * directory would imply encrypting the lost+found directory as well as
1158          * the filename "lost+found" itself.
1159          */
1160         if (inode->i_ino == EXT4_ROOT_INO)
1161                 return -EPERM;
1162 
1163         if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1164                 return -EINVAL;
1165 
1166         res = ext4_convert_inline_data(inode);
1167         if (res)
1168                 return res;
1169 
1170         /*
1171          * If a journal handle was specified, then the encryption context is
1172          * being set on a new inode via inheritance and is part of a larger
1173          * transaction to create the inode.  Otherwise the encryption context is
1174          * being set on an existing inode in its own transaction.  Only in the
1175          * latter case should the "retry on ENOSPC" logic be used.
1176          */
1177 
1178         if (handle) {
1179                 res = ext4_xattr_set_handle(handle, inode,
1180                                             EXT4_XATTR_INDEX_ENCRYPTION,
1181                                             EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1182                                             ctx, len, 0);
1183                 if (!res) {
1184                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1185                         ext4_clear_inode_state(inode,
1186                                         EXT4_STATE_MAY_INLINE_DATA);
1187                         /*
1188                          * Update inode->i_flags - S_ENCRYPTED will be enabled,
1189                          * S_DAX may be disabled
1190                          */
1191                         ext4_set_inode_flags(inode);
1192                 }
1193                 return res;
1194         }
1195 
1196         res = dquot_initialize(inode);
1197         if (res)
1198                 return res;
1199 retry:
1200         res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1201                                      &credits);
1202         if (res)
1203                 return res;
1204 
1205         handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1206         if (IS_ERR(handle))
1207                 return PTR_ERR(handle);
1208 
1209         res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1210                                     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1211                                     ctx, len, 0);
1212         if (!res) {
1213                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1214                 /*
1215                  * Update inode->i_flags - S_ENCRYPTED will be enabled,
1216                  * S_DAX may be disabled
1217                  */
1218                 ext4_set_inode_flags(inode);
1219                 res = ext4_mark_inode_dirty(handle, inode);
1220                 if (res)
1221                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1222         }
1223         res2 = ext4_journal_stop(handle);
1224 
1225         if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1226                 goto retry;
1227         if (!res)
1228                 res = res2;
1229         return res;
1230 }
1231 
1232 static bool ext4_dummy_context(struct inode *inode)
1233 {
1234         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1235 }
1236 
1237 static unsigned ext4_max_namelen(struct inode *inode)
1238 {
1239         return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1240                 EXT4_NAME_LEN;
1241 }
1242 
1243 static const struct fscrypt_operations ext4_cryptops = {
1244         .key_prefix             = "ext4:",
1245         .get_context            = ext4_get_context,
1246         .set_context            = ext4_set_context,
1247         .dummy_context          = ext4_dummy_context,
1248         .empty_dir              = ext4_empty_dir,
1249         .max_namelen            = ext4_max_namelen,
1250 };
1251 #endif
1252 
1253 #ifdef CONFIG_QUOTA
1254 static const char * const quotatypes[] = INITQFNAMES;
1255 #define QTYPE2NAME(t) (quotatypes[t])
1256 
1257 static int ext4_write_dquot(struct dquot *dquot);
1258 static int ext4_acquire_dquot(struct dquot *dquot);
1259 static int ext4_release_dquot(struct dquot *dquot);
1260 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1261 static int ext4_write_info(struct super_block *sb, int type);
1262 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1263                          const struct path *path);
1264 static int ext4_quota_on_mount(struct super_block *sb, int type);
1265 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1266                                size_t len, loff_t off);
1267 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1268                                 const char *data, size_t len, loff_t off);
1269 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1270                              unsigned int flags);
1271 static int ext4_enable_quotas(struct super_block *sb);
1272 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1273 
1274 static struct dquot **ext4_get_dquots(struct inode *inode)
1275 {
1276         return EXT4_I(inode)->i_dquot;
1277 }
1278 
1279 static const struct dquot_operations ext4_quota_operations = {
1280         .get_reserved_space     = ext4_get_reserved_space,
1281         .write_dquot            = ext4_write_dquot,
1282         .acquire_dquot          = ext4_acquire_dquot,
1283         .release_dquot          = ext4_release_dquot,
1284         .mark_dirty             = ext4_mark_dquot_dirty,
1285         .write_info             = ext4_write_info,
1286         .alloc_dquot            = dquot_alloc,
1287         .destroy_dquot          = dquot_destroy,
1288         .get_projid             = ext4_get_projid,
1289         .get_inode_usage        = ext4_get_inode_usage,
1290         .get_next_id            = ext4_get_next_id,
1291 };
1292 
1293 static const struct quotactl_ops ext4_qctl_operations = {
1294         .quota_on       = ext4_quota_on,
1295         .quota_off      = ext4_quota_off,
1296         .quota_sync     = dquot_quota_sync,
1297         .get_state      = dquot_get_state,
1298         .set_info       = dquot_set_dqinfo,
1299         .get_dqblk      = dquot_get_dqblk,
1300         .set_dqblk      = dquot_set_dqblk,
1301         .get_nextdqblk  = dquot_get_next_dqblk,
1302 };
1303 #endif
1304 
1305 static const struct super_operations ext4_sops = {
1306         .alloc_inode    = ext4_alloc_inode,
1307         .destroy_inode  = ext4_destroy_inode,
1308         .write_inode    = ext4_write_inode,
1309         .dirty_inode    = ext4_dirty_inode,
1310         .drop_inode     = ext4_drop_inode,
1311         .evict_inode    = ext4_evict_inode,
1312         .put_super      = ext4_put_super,
1313         .sync_fs        = ext4_sync_fs,
1314         .freeze_fs      = ext4_freeze,
1315         .unfreeze_fs    = ext4_unfreeze,
1316         .statfs         = ext4_statfs,
1317         .remount_fs     = ext4_remount,
1318         .show_options   = ext4_show_options,
1319 #ifdef CONFIG_QUOTA
1320         .quota_read     = ext4_quota_read,
1321         .quota_write    = ext4_quota_write,
1322         .get_dquots     = ext4_get_dquots,
1323 #endif
1324         .bdev_try_to_free_page = bdev_try_to_free_page,
1325 };
1326 
1327 static const struct export_operations ext4_export_ops = {
1328         .fh_to_dentry = ext4_fh_to_dentry,
1329         .fh_to_parent = ext4_fh_to_parent,
1330         .get_parent = ext4_get_parent,
1331 };
1332 
1333 enum {
1334         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1335         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1336         Opt_nouid32, Opt_debug, Opt_removed,
1337         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1338         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1339         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1340         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1341         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1342         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1343         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1344         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1345         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1346         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1347         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1348         Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1349         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1350         Opt_inode_readahead_blks, Opt_journal_ioprio,
1351         Opt_dioread_nolock, Opt_dioread_lock,
1352         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1353         Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1354 };
1355 
1356 static const match_table_t tokens = {
1357         {Opt_bsd_df, "bsddf"},
1358         {Opt_minix_df, "minixdf"},
1359         {Opt_grpid, "grpid"},
1360         {Opt_grpid, "bsdgroups"},
1361         {Opt_nogrpid, "nogrpid"},
1362         {Opt_nogrpid, "sysvgroups"},
1363         {Opt_resgid, "resgid=%u"},
1364         {Opt_resuid, "resuid=%u"},
1365         {Opt_sb, "sb=%u"},
1366         {Opt_err_cont, "errors=continue"},
1367         {Opt_err_panic, "errors=panic"},
1368         {Opt_err_ro, "errors=remount-ro"},
1369         {Opt_nouid32, "nouid32"},
1370         {Opt_debug, "debug"},
1371         {Opt_removed, "oldalloc"},
1372         {Opt_removed, "orlov"},
1373         {Opt_user_xattr, "user_xattr"},
1374         {Opt_nouser_xattr, "nouser_xattr"},
1375         {Opt_acl, "acl"},
1376         {Opt_noacl, "noacl"},
1377         {Opt_noload, "norecovery"},
1378         {Opt_noload, "noload"},
1379         {Opt_removed, "nobh"},
1380         {Opt_removed, "bh"},
1381         {Opt_commit, "commit=%u"},
1382         {Opt_min_batch_time, "min_batch_time=%u"},
1383         {Opt_max_batch_time, "max_batch_time=%u"},
1384         {Opt_journal_dev, "journal_dev=%u"},
1385         {Opt_journal_path, "journal_path=%s"},
1386         {Opt_journal_checksum, "journal_checksum"},
1387         {Opt_nojournal_checksum, "nojournal_checksum"},
1388         {Opt_journal_async_commit, "journal_async_commit"},
1389         {Opt_abort, "abort"},
1390         {Opt_data_journal, "data=journal"},
1391         {Opt_data_ordered, "data=ordered"},
1392         {Opt_data_writeback, "data=writeback"},
1393         {Opt_data_err_abort, "data_err=abort"},
1394         {Opt_data_err_ignore, "data_err=ignore"},
1395         {Opt_offusrjquota, "usrjquota="},
1396         {Opt_usrjquota, "usrjquota=%s"},
1397         {Opt_offgrpjquota, "grpjquota="},
1398         {Opt_grpjquota, "grpjquota=%s"},
1399         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1400         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1401         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1402         {Opt_grpquota, "grpquota"},
1403         {Opt_noquota, "noquota"},
1404         {Opt_quota, "quota"},
1405         {Opt_usrquota, "usrquota"},
1406         {Opt_prjquota, "prjquota"},
1407         {Opt_barrier, "barrier=%u"},
1408         {Opt_barrier, "barrier"},
1409         {Opt_nobarrier, "nobarrier"},
1410         {Opt_i_version, "i_version"},
1411         {Opt_dax, "dax"},
1412         {Opt_stripe, "stripe=%u"},
1413         {Opt_delalloc, "delalloc"},
1414         {Opt_lazytime, "lazytime"},
1415         {Opt_nolazytime, "nolazytime"},
1416         {Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1417         {Opt_nodelalloc, "nodelalloc"},
1418         {Opt_removed, "mblk_io_submit"},
1419         {Opt_removed, "nomblk_io_submit"},
1420         {Opt_block_validity, "block_validity"},
1421         {Opt_noblock_validity, "noblock_validity"},
1422         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1423         {Opt_journal_ioprio, "journal_ioprio=%u"},
1424         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1425         {Opt_auto_da_alloc, "auto_da_alloc"},
1426         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1427         {Opt_dioread_nolock, "dioread_nolock"},
1428         {Opt_dioread_lock, "dioread_lock"},
1429         {Opt_discard, "discard"},
1430         {Opt_nodiscard, "nodiscard"},
1431         {Opt_init_itable, "init_itable=%u"},
1432         {Opt_init_itable, "init_itable"},
1433         {Opt_noinit_itable, "noinit_itable"},
1434         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1435         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1436         {Opt_nombcache, "nombcache"},
1437         {Opt_nombcache, "no_mbcache"},  /* for backward compatibility */
1438         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1439         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1440         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1441         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1442         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1443         {Opt_err, NULL},
1444 };
1445 
1446 static ext4_fsblk_t get_sb_block(void **data)
1447 {
1448         ext4_fsblk_t    sb_block;
1449         char            *options = (char *) *data;
1450 
1451         if (!options || strncmp(options, "sb=", 3) != 0)
1452                 return 1;       /* Default location */
1453 
1454         options += 3;
1455         /* TODO: use simple_strtoll with >32bit ext4 */
1456         sb_block = simple_strtoul(options, &options, 0);
1457         if (*options && *options != ',') {
1458                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1459                        (char *) *data);
1460                 return 1;
1461         }
1462         if (*options == ',')
1463                 options++;
1464         *data = (void *) options;
1465 
1466         return sb_block;
1467 }
1468 
1469 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1470 static const char deprecated_msg[] =
1471         "Mount option \"%s\" will be removed by %s\n"
1472         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1473 
1474 #ifdef CONFIG_QUOTA
1475 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1476 {
1477         struct ext4_sb_info *sbi = EXT4_SB(sb);
1478         char *qname;
1479         int ret = -1;
1480 
1481         if (sb_any_quota_loaded(sb) &&
1482                 !sbi->s_qf_names[qtype]) {
1483                 ext4_msg(sb, KERN_ERR,
1484                         "Cannot change journaled "
1485                         "quota options when quota turned on");
1486                 return -1;
1487         }
1488         if (ext4_has_feature_quota(sb)) {
1489                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1490                          "ignored when QUOTA feature is enabled");
1491                 return 1;
1492         }
1493         qname = match_strdup(args);
1494         if (!qname) {
1495                 ext4_msg(sb, KERN_ERR,
1496                         "Not enough memory for storing quotafile name");
1497                 return -1;
1498         }
1499         if (sbi->s_qf_names[qtype]) {
1500                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1501                         ret = 1;
1502                 else
1503                         ext4_msg(sb, KERN_ERR,
1504                                  "%s quota file already specified",
1505                                  QTYPE2NAME(qtype));
1506                 goto errout;
1507         }
1508         if (strchr(qname, '/')) {
1509                 ext4_msg(sb, KERN_ERR,
1510                         "quotafile must be on filesystem root");
1511                 goto errout;
1512         }
1513         sbi->s_qf_names[qtype] = qname;
1514         set_opt(sb, QUOTA);
1515         return 1;
1516 errout:
1517         kfree(qname);
1518         return ret;
1519 }
1520 
1521 static int clear_qf_name(struct super_block *sb, int qtype)
1522 {
1523 
1524         struct ext4_sb_info *sbi = EXT4_SB(sb);
1525 
1526         if (sb_any_quota_loaded(sb) &&
1527                 sbi->s_qf_names[qtype]) {
1528                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1529                         " when quota turned on");
1530                 return -1;
1531         }
1532         kfree(sbi->s_qf_names[qtype]);
1533         sbi->s_qf_names[qtype] = NULL;
1534         return 1;
1535 }
1536 #endif
1537 
1538 #define MOPT_SET        0x0001
1539 #define MOPT_CLEAR      0x0002
1540 #define MOPT_NOSUPPORT  0x0004
1541 #define MOPT_EXPLICIT   0x0008
1542 #define MOPT_CLEAR_ERR  0x0010
1543 #define MOPT_GTE0       0x0020
1544 #ifdef CONFIG_QUOTA
1545 #define MOPT_Q          0
1546 #define MOPT_QFMT       0x0040
1547 #else
1548 #define MOPT_Q          MOPT_NOSUPPORT
1549 #define MOPT_QFMT       MOPT_NOSUPPORT
1550 #endif
1551 #define MOPT_DATAJ      0x0080
1552 #define MOPT_NO_EXT2    0x0100
1553 #define MOPT_NO_EXT3    0x0200
1554 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1555 #define MOPT_STRING     0x0400
1556 
1557 static const struct mount_opts {
1558         int     token;
1559         int     mount_opt;
1560         int     flags;
1561 } ext4_mount_opts[] = {
1562         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1563         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1564         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1565         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1566         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1567         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1568         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1569          MOPT_EXT4_ONLY | MOPT_SET},
1570         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1571          MOPT_EXT4_ONLY | MOPT_CLEAR},
1572         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1573         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1574         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1575          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1576         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1577          MOPT_EXT4_ONLY | MOPT_CLEAR},
1578         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1579          MOPT_EXT4_ONLY | MOPT_CLEAR},
1580         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1581          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1582         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1583                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1584          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1585         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1586         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1587         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1588         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1589         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1590          MOPT_NO_EXT2},
1591         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1592          MOPT_NO_EXT2},
1593         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1594         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1595         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1596         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1597         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1598         {Opt_commit, 0, MOPT_GTE0},
1599         {Opt_max_batch_time, 0, MOPT_GTE0},
1600         {Opt_min_batch_time, 0, MOPT_GTE0},
1601         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1602         {Opt_init_itable, 0, MOPT_GTE0},
1603         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1604         {Opt_stripe, 0, MOPT_GTE0},
1605         {Opt_resuid, 0, MOPT_GTE0},
1606         {Opt_resgid, 0, MOPT_GTE0},
1607         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1608         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1609         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1610         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1611         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1612         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1613          MOPT_NO_EXT2 | MOPT_DATAJ},
1614         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1615         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1616 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1617         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1618         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1619 #else
1620         {Opt_acl, 0, MOPT_NOSUPPORT},
1621         {Opt_noacl, 0, MOPT_NOSUPPORT},
1622 #endif
1623         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1624         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1625         {Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1626         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1627         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1628                                                         MOPT_SET | MOPT_Q},
1629         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1630                                                         MOPT_SET | MOPT_Q},
1631         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1632                                                         MOPT_SET | MOPT_Q},
1633         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1634                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1635                                                         MOPT_CLEAR | MOPT_Q},
1636         {Opt_usrjquota, 0, MOPT_Q},
1637         {Opt_grpjquota, 0, MOPT_Q},
1638         {Opt_offusrjquota, 0, MOPT_Q},
1639         {Opt_offgrpjquota, 0, MOPT_Q},
1640         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1641         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1642         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1643         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1644         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1645         {Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1646         {Opt_err, 0, 0}
1647 };
1648 
1649 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1650                             substring_t *args, unsigned long *journal_devnum,
1651                             unsigned int *journal_ioprio, int is_remount)
1652 {
1653         struct ext4_sb_info *sbi = EXT4_SB(sb);
1654         const struct mount_opts *m;
1655         kuid_t uid;
1656         kgid_t gid;
1657         int arg = 0;
1658 
1659 #ifdef CONFIG_QUOTA
1660         if (token == Opt_usrjquota)
1661                 return set_qf_name(sb, USRQUOTA, &args[0]);
1662         else if (token == Opt_grpjquota)
1663                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1664         else if (token == Opt_offusrjquota)
1665                 return clear_qf_name(sb, USRQUOTA);
1666         else if (token == Opt_offgrpjquota)
1667                 return clear_qf_name(sb, GRPQUOTA);
1668 #endif
1669         switch (token) {
1670         case Opt_noacl:
1671         case Opt_nouser_xattr:
1672                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1673                 break;
1674         case Opt_sb:
1675                 return 1;       /* handled by get_sb_block() */
1676         case Opt_removed:
1677                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1678                 return 1;
1679         case Opt_abort:
1680                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1681                 return 1;
1682         case Opt_i_version:
1683                 sb->s_flags |= SB_I_VERSION;
1684                 return 1;
1685         case Opt_lazytime:
1686                 sb->s_flags |= SB_LAZYTIME;
1687                 return 1;
1688         case Opt_nolazytime:
1689                 sb->s_flags &= ~SB_LAZYTIME;
1690                 return 1;
1691         }
1692 
1693         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1694                 if (token == m->token)
1695                         break;
1696 
1697         if (m->token == Opt_err) {
1698                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1699                          "or missing value", opt);
1700                 return -1;
1701         }
1702 
1703         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1704                 ext4_msg(sb, KERN_ERR,
1705                          "Mount option \"%s\" incompatible with ext2", opt);
1706                 return -1;
1707         }
1708         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1709                 ext4_msg(sb, KERN_ERR,
1710                          "Mount option \"%s\" incompatible with ext3", opt);
1711                 return -1;
1712         }
1713 
1714         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1715                 return -1;
1716         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1717                 return -1;
1718         if (m->flags & MOPT_EXPLICIT) {
1719                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1720                         set_opt2(sb, EXPLICIT_DELALLOC);
1721                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1722                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1723                 } else
1724                         return -1;
1725         }
1726         if (m->flags & MOPT_CLEAR_ERR)
1727                 clear_opt(sb, ERRORS_MASK);
1728         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1729                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1730                          "options when quota turned on");
1731                 return -1;
1732         }
1733 
1734         if (m->flags & MOPT_NOSUPPORT) {
1735                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1736         } else if (token == Opt_commit) {
1737                 if (arg == 0)
1738                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1739                 sbi->s_commit_interval = HZ * arg;
1740         } else if (token == Opt_debug_want_extra_isize) {
1741                 sbi->s_want_extra_isize = arg;
1742         } else if (token == Opt_max_batch_time) {
1743                 sbi->s_max_batch_time = arg;
1744         } else if (token == Opt_min_batch_time) {
1745                 sbi->s_min_batch_time = arg;
1746         } else if (token == Opt_inode_readahead_blks) {
1747                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1748                         ext4_msg(sb, KERN_ERR,
1749                                  "EXT4-fs: inode_readahead_blks must be "
1750                                  "0 or a power of 2 smaller than 2^31");
1751                         return -1;
1752                 }
1753                 sbi->s_inode_readahead_blks = arg;
1754         } else if (token == Opt_init_itable) {
1755                 set_opt(sb, INIT_INODE_TABLE);
1756                 if (!args->from)
1757                         arg = EXT4_DEF_LI_WAIT_MULT;
1758                 sbi->s_li_wait_mult = arg;
1759         } else if (token == Opt_max_dir_size_kb) {
1760                 sbi->s_max_dir_size_kb = arg;
1761         } else if (token == Opt_stripe) {
1762                 sbi->s_stripe = arg;
1763         } else if (token == Opt_resuid) {
1764                 uid = make_kuid(current_user_ns(), arg);
1765                 if (!uid_valid(uid)) {
1766                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1767                         return -1;
1768                 }
1769                 sbi->s_resuid = uid;
1770         } else if (token == Opt_resgid) {
1771                 gid = make_kgid(current_user_ns(), arg);
1772                 if (!gid_valid(gid)) {
1773                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1774                         return -1;
1775                 }
1776                 sbi->s_resgid = gid;
1777         } else if (token == Opt_journal_dev) {
1778                 if (is_remount) {
1779                         ext4_msg(sb, KERN_ERR,
1780                                  "Cannot specify journal on remount");
1781                         return -1;
1782                 }
1783                 *journal_devnum = arg;
1784         } else if (token == Opt_journal_path) {
1785                 char *journal_path;
1786                 struct inode *journal_inode;
1787                 struct path path;
1788                 int error;
1789 
1790                 if (is_remount) {
1791                         ext4_msg(sb, KERN_ERR,
1792                                  "Cannot specify journal on remount");
1793                         return -1;
1794                 }
1795                 journal_path = match_strdup(&args[0]);
1796                 if (!journal_path) {
1797                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1798                                 "journal device string");
1799                         return -1;
1800                 }
1801 
1802                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1803                 if (error) {
1804                         ext4_msg(sb, KERN_ERR, "error: could not find "
1805                                 "journal device path: error %d", error);
1806                         kfree(journal_path);
1807                         return -1;
1808                 }
1809 
1810                 journal_inode = d_inode(path.dentry);
1811                 if (!S_ISBLK(journal_inode->i_mode)) {
1812                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1813                                 "is not a block device", journal_path);
1814                         path_put(&path);
1815                         kfree(journal_path);
1816                         return -1;
1817                 }
1818 
1819                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1820                 path_put(&path);
1821                 kfree(journal_path);
1822         } else if (token == Opt_journal_ioprio) {
1823                 if (arg > 7) {
1824                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1825                                  " (must be 0-7)");
1826                         return -1;
1827                 }
1828                 *journal_ioprio =
1829                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1830         } else if (token == Opt_test_dummy_encryption) {
1831 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1832                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1833                 ext4_msg(sb, KERN_WARNING,
1834                          "Test dummy encryption mode enabled");
1835 #else
1836                 ext4_msg(sb, KERN_WARNING,
1837                          "Test dummy encryption mount option ignored");
1838 #endif
1839         } else if (m->flags & MOPT_DATAJ) {
1840                 if (is_remount) {
1841                         if (!sbi->s_journal)
1842                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1843                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1844                                 ext4_msg(sb, KERN_ERR,
1845                                          "Cannot change data mode on remount");
1846                                 return -1;
1847                         }
1848                 } else {
1849                         clear_opt(sb, DATA_FLAGS);
1850                         sbi->s_mount_opt |= m->mount_opt;
1851                 }
1852 #ifdef CONFIG_QUOTA
1853         } else if (m->flags & MOPT_QFMT) {
1854                 if (sb_any_quota_loaded(sb) &&
1855                     sbi->s_jquota_fmt != m->mount_opt) {
1856                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1857                                  "quota options when quota turned on");
1858                         return -1;
1859                 }
1860                 if (ext4_has_feature_quota(sb)) {
1861                         ext4_msg(sb, KERN_INFO,
1862                                  "Quota format mount options ignored "
1863                                  "when QUOTA feature is enabled");
1864                         return 1;
1865                 }
1866                 sbi->s_jquota_fmt = m->mount_opt;
1867 #endif
1868         } else if (token == Opt_dax) {
1869 #ifdef CONFIG_FS_DAX
1870                 ext4_msg(sb, KERN_WARNING,
1871                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1872                         sbi->s_mount_opt |= m->mount_opt;
1873 #else
1874                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1875                 return -1;
1876 #endif
1877         } else if (token == Opt_data_err_abort) {
1878                 sbi->s_mount_opt |= m->mount_opt;
1879         } else if (token == Opt_data_err_ignore) {
1880                 sbi->s_mount_opt &= ~m->mount_opt;
1881         } else {
1882                 if (!args->from)
1883                         arg = 1;
1884                 if (m->flags & MOPT_CLEAR)
1885                         arg = !arg;
1886                 else if (unlikely(!(m->flags & MOPT_SET))) {
1887                         ext4_msg(sb, KERN_WARNING,
1888                                  "buggy handling of option %s", opt);
1889                         WARN_ON(1);
1890                         return -1;
1891                 }
1892                 if (arg != 0)
1893                         sbi->s_mount_opt |= m->mount_opt;
1894                 else
1895                         sbi->s_mount_opt &= ~m->mount_opt;
1896         }
1897         return 1;
1898 }
1899 
1900 static int parse_options(char *options, struct super_block *sb,
1901                          unsigned long *journal_devnum,
1902                          unsigned int *journal_ioprio,
1903                          int is_remount)
1904 {
1905         struct ext4_sb_info *sbi = EXT4_SB(sb);
1906         char *p;
1907         substring_t args[MAX_OPT_ARGS];
1908         int token;
1909 
1910         if (!options)
1911                 return 1;
1912 
1913         while ((p = strsep(&options, ",")) != NULL) {
1914                 if (!*p)
1915                         continue;
1916                 /*
1917                  * Initialize args struct so we know whether arg was
1918                  * found; some options take optional arguments.
1919                  */
1920                 args[0].to = args[0].from = NULL;
1921                 token = match_token(p, tokens, args);
1922                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1923                                      journal_ioprio, is_remount) < 0)
1924                         return 0;
1925         }
1926 #ifdef CONFIG_QUOTA
1927         /*
1928          * We do the test below only for project quotas. 'usrquota' and
1929          * 'grpquota' mount options are allowed even without quota feature
1930          * to support legacy quotas in quota files.
1931          */
1932         if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1933                 ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1934                          "Cannot enable project quota enforcement.");
1935                 return 0;
1936         }
1937         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1938                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1939                         clear_opt(sb, USRQUOTA);
1940 
1941                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1942                         clear_opt(sb, GRPQUOTA);
1943 
1944                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1945                         ext4_msg(sb, KERN_ERR, "old and new quota "
1946                                         "format mixing");
1947                         return 0;
1948                 }
1949 
1950                 if (!sbi->s_jquota_fmt) {
1951                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1952                                         "not specified");
1953                         return 0;
1954                 }
1955         }
1956 #endif
1957         if (test_opt(sb, DIOREAD_NOLOCK)) {
1958                 int blocksize =
1959                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1960 
1961                 if (blocksize < PAGE_SIZE) {
1962                         ext4_msg(sb, KERN_ERR, "can't mount with "
1963                                  "dioread_nolock if block size != PAGE_SIZE");
1964                         return 0;
1965                 }
1966         }
1967         return 1;
1968 }
1969 
1970 static inline void ext4_show_quota_options(struct seq_file *seq,
1971                                            struct super_block *sb)
1972 {
1973 #if defined(CONFIG_QUOTA)
1974         struct ext4_sb_info *sbi = EXT4_SB(sb);
1975 
1976         if (sbi->s_jquota_fmt) {
1977                 char *fmtname = "";
1978 
1979                 switch (sbi->s_jquota_fmt) {
1980                 case QFMT_VFS_OLD:
1981                         fmtname = "vfsold";
1982                         break;
1983                 case QFMT_VFS_V0:
1984                         fmtname = "vfsv0";
1985                         break;
1986                 case QFMT_VFS_V1:
1987                         fmtname = "vfsv1";
1988                         break;
1989                 }
1990                 seq_printf(seq, ",jqfmt=%s", fmtname);
1991         }
1992 
1993         if (sbi->s_qf_names[USRQUOTA])
1994                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1995 
1996         if (sbi->s_qf_names[GRPQUOTA])
1997                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1998 #endif
1999 }
2000 
2001 static const char *token2str(int token)
2002 {
2003         const struct match_token *t;
2004 
2005         for (t = tokens; t->token != Opt_err; t++)
2006                 if (t->token == token && !strchr(t->pattern, '='))
2007                         break;
2008         return t->pattern;
2009 }
2010 
2011 /*
2012  * Show an option if
2013  *  - it's set to a non-default value OR
2014  *  - if the per-sb default is different from the global default
2015  */
2016 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2017                               int nodefs)
2018 {
2019         struct ext4_sb_info *sbi = EXT4_SB(sb);
2020         struct ext4_super_block *es = sbi->s_es;
2021         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
2022         const struct mount_opts *m;
2023         char sep = nodefs ? '\n' : ',';
2024 
2025 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2026 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2027 
2028         if (sbi->s_sb_block != 1)
2029                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2030 
2031         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2032                 int want_set = m->flags & MOPT_SET;
2033                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2034                     (m->flags & MOPT_CLEAR_ERR))
2035                         continue;
2036                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2037                         continue; /* skip if same as the default */
2038                 if ((want_set &&
2039                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2040                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2041                         continue; /* select Opt_noFoo vs Opt_Foo */
2042                 SEQ_OPTS_PRINT("%s", token2str(m->token));
2043         }
2044 
2045         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2046             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2047                 SEQ_OPTS_PRINT("resuid=%u",
2048                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
2049         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2050             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2051                 SEQ_OPTS_PRINT("resgid=%u",
2052                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
2053         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2054         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2055                 SEQ_OPTS_PUTS("errors=remount-ro");
2056         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2057                 SEQ_OPTS_PUTS("errors=continue");
2058         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2059                 SEQ_OPTS_PUTS("errors=panic");
2060         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2061                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2062         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2063                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2064         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2065                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2066         if (sb->s_flags & SB_I_VERSION)
2067                 SEQ_OPTS_PUTS("i_version");
2068         if (nodefs || sbi->s_stripe)
2069                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2070         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2071                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2072                         SEQ_OPTS_PUTS("data=journal");
2073                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2074                         SEQ_OPTS_PUTS("data=ordered");
2075                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2076                         SEQ_OPTS_PUTS("data=writeback");
2077         }
2078         if (nodefs ||
2079             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2080                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2081                                sbi->s_inode_readahead_blks);
2082 
2083         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2084                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2085                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2086         if (nodefs || sbi->s_max_dir_size_kb)
2087                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2088         if (test_opt(sb, DATA_ERR_ABORT))
2089                 SEQ_OPTS_PUTS("data_err=abort");
2090 
2091         ext4_show_quota_options(seq, sb);
2092         return 0;
2093 }
2094 
2095 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2096 {
2097         return _ext4_show_options(seq, root->d_sb, 0);
2098 }
2099 
2100 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2101 {
2102         struct super_block *sb = seq->private;
2103         int rc;
2104 
2105         seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2106         rc = _ext4_show_options(seq, sb, 1);
2107         seq_puts(seq, "\n");
2108         return rc;
2109 }
2110 
2111 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2112                             int read_only)
2113 {
2114         struct ext4_sb_info *sbi = EXT4_SB(sb);
2115         int res = 0;
2116 
2117         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2118                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2119                          "forcing read-only mode");
2120                 res = SB_RDONLY;
2121         }
2122         if (read_only)
2123                 goto done;
2124         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2125                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2126                          "running e2fsck is recommended");
2127         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2128                 ext4_msg(sb, KERN_WARNING,
2129                          "warning: mounting fs with errors, "
2130                          "running e2fsck is recommended");
2131         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2132                  le16_to_cpu(es->s_mnt_count) >=
2133                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2134                 ext4_msg(sb, KERN_WARNING,
2135                          "warning: maximal mount count reached, "
2136                          "running e2fsck is recommended");
2137         else if (le32_to_cpu(es->s_checkinterval) &&
2138                 (le32_to_cpu(es->s_lastcheck) +
2139                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2140                 ext4_msg(sb, KERN_WARNING,
2141                          "warning: checktime reached, "
2142                          "running e2fsck is recommended");
2143         if (!sbi->s_journal)
2144                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2145         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2146                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2147         le16_add_cpu(&es->s_mnt_count, 1);
2148         es->s_mtime = cpu_to_le32(get_seconds());
2149         ext4_update_dynamic_rev(sb);
2150         if (sbi->s_journal)
2151                 ext4_set_feature_journal_needs_recovery(sb);
2152 
2153         ext4_commit_super(sb, 1);
2154 done:
2155         if (test_opt(sb, DEBUG))
2156                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2157                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2158                         sb->s_blocksize,
2159                         sbi->s_groups_count,
2160                         EXT4_BLOCKS_PER_GROUP(sb),
2161                         EXT4_INODES_PER_GROUP(sb),
2162                         sbi->s_mount_opt, sbi->s_mount_opt2);
2163 
2164         cleancache_init_fs(sb);
2165         return res;
2166 }
2167 
2168 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2169 {
2170         struct ext4_sb_info *sbi = EXT4_SB(sb);
2171         struct flex_groups *new_groups;
2172         int size;
2173 
2174         if (!sbi->s_log_groups_per_flex)
2175                 return 0;
2176 
2177         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2178         if (size <= sbi->s_flex_groups_allocated)
2179                 return 0;
2180 
2181         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2182         new_groups = kvzalloc(size, GFP_KERNEL);
2183         if (!new_groups) {
2184                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2185                          size / (int) sizeof(struct flex_groups));
2186                 return -ENOMEM;
2187         }
2188 
2189         if (sbi->s_flex_groups) {
2190                 memcpy(new_groups, sbi->s_flex_groups,
2191                        (sbi->s_flex_groups_allocated *
2192                         sizeof(struct flex_groups)));
2193                 kvfree(sbi->s_flex_groups);
2194         }
2195         sbi->s_flex_groups = new_groups;
2196         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2197         return 0;
2198 }
2199 
2200 static int ext4_fill_flex_info(struct super_block *sb)
2201 {
2202         struct ext4_sb_info *sbi = EXT4_SB(sb);
2203         struct ext4_group_desc *gdp = NULL;
2204         ext4_group_t flex_group;
2205         int i, err;
2206 
2207         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2208         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2209                 sbi->s_log_groups_per_flex = 0;
2210                 return 1;
2211         }
2212 
2213         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2214         if (err)
2215                 goto failed;
2216 
2217         for (i = 0; i < sbi->s_groups_count; i++) {
2218                 gdp = ext4_get_group_desc(sb, i, NULL);
2219 
2220                 flex_group = ext4_flex_group(sbi, i);
2221                 atomic_add(ext4_free_inodes_count(sb, gdp),
2222                            &sbi->s_flex_groups[flex_group].free_inodes);
2223                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2224                              &sbi->s_flex_groups[flex_group].free_clusters);
2225                 atomic_add(ext4_used_dirs_count(sb, gdp),
2226                            &sbi->s_flex_groups[flex_group].used_dirs);
2227         }
2228 
2229         return 1;
2230 failed:
2231         return 0;
2232 }
2233 
2234 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2235                                    struct ext4_group_desc *gdp)
2236 {
2237         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2238         __u16 crc = 0;
2239         __le32 le_group = cpu_to_le32(block_group);
2240         struct ext4_sb_info *sbi = EXT4_SB(sb);
2241 
2242         if (ext4_has_metadata_csum(sbi->s_sb)) {
2243                 /* Use new metadata_csum algorithm */
2244                 __u32 csum32;
2245                 __u16 dummy_csum = 0;
2246 
2247                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2248                                      sizeof(le_group));
2249                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2250                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2251                                      sizeof(dummy_csum));
2252                 offset += sizeof(dummy_csum);
2253                 if (offset < sbi->s_desc_size)
2254                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2255                                              sbi->s_desc_size - offset);
2256 
2257                 crc = csum32 & 0xFFFF;
2258                 goto out;
2259         }
2260 
2261         /* old crc16 code */
2262         if (!ext4_has_feature_gdt_csum(sb))
2263                 return 0;
2264 
2265         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2266         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2267         crc = crc16(crc, (__u8 *)gdp, offset);
2268         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2269         /* for checksum of struct ext4_group_desc do the rest...*/
2270         if (ext4_has_feature_64bit(sb) &&
2271             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2272                 crc = crc16(crc, (__u8 *)gdp + offset,
2273                             le16_to_cpu(sbi->s_es->s_desc_size) -
2274                                 offset);
2275 
2276 out:
2277         return cpu_to_le16(crc);
2278 }
2279 
2280 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2281                                 struct ext4_group_desc *gdp)
2282 {
2283         if (ext4_has_group_desc_csum(sb) &&
2284             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2285                 return 0;
2286 
2287         return 1;
2288 }
2289 
2290 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2291                               struct ext4_group_desc *gdp)
2292 {
2293         if (!ext4_has_group_desc_csum(sb))
2294                 return;
2295         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2296 }
2297 
2298 /* Called at mount-time, super-block is locked */
2299 static int ext4_check_descriptors(struct super_block *sb,
2300                                   ext4_fsblk_t sb_block,
2301                                   ext4_group_t *first_not_zeroed)
2302 {
2303         struct ext4_sb_info *sbi = EXT4_SB(sb);
2304         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2305         ext4_fsblk_t last_block;
2306         ext4_fsblk_t block_bitmap;
2307         ext4_fsblk_t inode_bitmap;
2308         ext4_fsblk_t inode_table;
2309         int flexbg_flag = 0;
2310         ext4_group_t i, grp = sbi->s_groups_count;
2311 
2312         if (ext4_has_feature_flex_bg(sb))
2313                 flexbg_flag = 1;
2314 
2315         ext4_debug("Checking group descriptors");
2316 
2317         for (i = 0; i < sbi->s_groups_count; i++) {
2318                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2319 
2320                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2321                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2322                 else
2323                         last_block = first_block +
2324                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2325 
2326                 if ((grp == sbi->s_groups_count) &&
2327                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2328                         grp = i;
2329 
2330                 block_bitmap = ext4_block_bitmap(sb, gdp);
2331                 if (block_bitmap == sb_block) {
2332                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2333                                  "Block bitmap for group %u overlaps "
2334                                  "superblock", i);
2335                 }
2336                 if (block_bitmap < first_block || block_bitmap > last_block) {
2337                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2338                                "Block bitmap for group %u not in group "
2339                                "(block %llu)!", i, block_bitmap);
2340                         return 0;
2341                 }
2342                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2343                 if (inode_bitmap == sb_block) {
2344                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2345                                  "Inode bitmap for group %u overlaps "
2346                                  "superblock", i);
2347                 }
2348                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2349                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2350                                "Inode bitmap for group %u not in group "
2351                                "(block %llu)!", i, inode_bitmap);
2352                         return 0;
2353                 }
2354                 inode_table = ext4_inode_table(sb, gdp);
2355                 if (inode_table == sb_block) {
2356                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2357                                  "Inode table for group %u overlaps "
2358                                  "superblock", i);
2359                 }
2360                 if (inode_table < first_block ||
2361                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2362                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2363                                "Inode table for group %u not in group "
2364                                "(block %llu)!", i, inode_table);
2365                         return 0;
2366                 }
2367                 ext4_lock_group(sb, i);
2368                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2369                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2370                                  "Checksum for group %u failed (%u!=%u)",
2371                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2372                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2373                         if (!sb_rdonly(sb)) {
2374                                 ext4_unlock_group(sb, i);
2375                                 return 0;
2376                         }
2377                 }
2378                 ext4_unlock_group(sb, i);
2379                 if (!flexbg_flag)
2380                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2381         }
2382         if (NULL != first_not_zeroed)
2383                 *first_not_zeroed = grp;
2384         return 1;
2385 }
2386 
2387 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2388  * the superblock) which were deleted from all directories, but held open by
2389  * a process at the time of a crash.  We walk the list and try to delete these
2390  * inodes at recovery time (only with a read-write filesystem).
2391  *
2392  * In order to keep the orphan inode chain consistent during traversal (in
2393  * case of crash during recovery), we link each inode into the superblock
2394  * orphan list_head and handle it the same way as an inode deletion during
2395  * normal operation (which journals the operations for us).
2396  *
2397  * We only do an iget() and an iput() on each inode, which is very safe if we
2398  * accidentally point at an in-use or already deleted inode.  The worst that
2399  * can happen in this case is that we get a "bit already cleared" message from
2400  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2401  * e2fsck was run on this filesystem, and it must have already done the orphan
2402  * inode cleanup for us, so we can safely abort without any further action.
2403  */
2404 static void ext4_orphan_cleanup(struct super_block *sb,
2405                                 struct ext4_super_block *es)
2406 {
2407         unsigned int s_flags = sb->s_flags;
2408         int ret, nr_orphans = 0, nr_truncates = 0;
2409 #ifdef CONFIG_QUOTA
2410         int quota_update = 0;
2411         int i;
2412 #endif
2413         if (!es->s_last_orphan) {
2414                 jbd_debug(4, "no orphan inodes to clean up\n");
2415                 return;
2416         }
2417 
2418         if (bdev_read_only(sb->s_bdev)) {
2419                 ext4_msg(sb, KERN_ERR, "write access "
2420                         "unavailable, skipping orphan cleanup");
2421                 return;
2422         }
2423 
2424         /* Check if feature set would not allow a r/w mount */
2425         if (!ext4_feature_set_ok(sb, 0)) {
2426                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2427                          "unknown ROCOMPAT features");
2428                 return;
2429         }
2430 
2431         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2432                 /* don't clear list on RO mount w/ errors */
2433                 if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2434                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2435                                   "clearing orphan list.\n");
2436                         es->s_last_orphan = 0;
2437                 }
2438                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2439                 return;
2440         }
2441 
2442         if (s_flags & SB_RDONLY) {
2443                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2444                 sb->s_flags &= ~SB_RDONLY;
2445         }
2446 #ifdef CONFIG_QUOTA
2447         /* Needed for iput() to work correctly and not trash data */
2448         sb->s_flags |= SB_ACTIVE;
2449 
2450         /*
2451          * Turn on quotas which were not enabled for read-only mounts if
2452          * filesystem has quota feature, so that they are updated correctly.
2453          */
2454         if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2455                 int ret = ext4_enable_quotas(sb);
2456 
2457                 if (!ret)
2458                         quota_update = 1;
2459                 else
2460                         ext4_msg(sb, KERN_ERR,
2461                                 "Cannot turn on quotas: error %d", ret);
2462         }
2463 
2464         /* Turn on journaled quotas used for old sytle */
2465         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2466                 if (EXT4_SB(sb)->s_qf_names[i]) {
2467                         int ret = ext4_quota_on_mount(sb, i);
2468 
2469                         if (!ret)
2470                                 quota_update = 1;
2471                         else
2472                                 ext4_msg(sb, KERN_ERR,
2473                                         "Cannot turn on journaled "
2474                                         "quota: type %d: error %d", i, ret);
2475                 }
2476         }
2477 #endif
2478 
2479         while (es->s_last_orphan) {
2480                 struct inode *inode;
2481 
2482                 /*
2483                  * We may have encountered an error during cleanup; if
2484                  * so, skip the rest.
2485                  */
2486                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2487                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2488                         es->s_last_orphan = 0;
2489                         break;
2490                 }
2491 
2492                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2493                 if (IS_ERR(inode)) {
2494                         es->s_last_orphan = 0;
2495                         break;
2496                 }
2497 
2498                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2499                 dquot_initialize(inode);
2500                 if (inode->i_nlink) {
2501                         if (test_opt(sb, DEBUG))
2502                                 ext4_msg(sb, KERN_DEBUG,
2503                                         "%s: truncating inode %lu to %lld bytes",
2504                                         __func__, inode->i_ino, inode->i_size);
2505                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2506                                   inode->i_ino, inode->i_size);
2507                         inode_lock(inode);
2508                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2509                         ret = ext4_truncate(inode);
2510                         if (ret)
2511                                 ext4_std_error(inode->i_sb, ret);
2512                         inode_unlock(inode);
2513                         nr_truncates++;
2514                 } else {
2515                         if (test_opt(sb, DEBUG))
2516                                 ext4_msg(sb, KERN_DEBUG,
2517                                         "%s: deleting unreferenced inode %lu",
2518                                         __func__, inode->i_ino);
2519                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2520                                   inode->i_ino);
2521                         nr_orphans++;
2522                 }
2523                 iput(inode);  /* The delete magic happens here! */
2524         }
2525 
2526 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2527 
2528         if (nr_orphans)
2529                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2530                        PLURAL(nr_orphans));
2531         if (nr_truncates)
2532                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2533                        PLURAL(nr_truncates));
2534 #ifdef CONFIG_QUOTA
2535         /* Turn off quotas if they were enabled for orphan cleanup */
2536         if (quota_update) {
2537                 for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2538                         if (sb_dqopt(sb)->files[i])
2539                                 dquot_quota_off(sb, i);
2540                 }
2541         }
2542 #endif
2543         sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2544 }
2545 
2546 /*
2547  * Maximal extent format file size.
2548  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2549  * extent format containers, within a sector_t, and within i_blocks
2550  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2551  * so that won't be a limiting factor.
2552  *
2553  * However there is other limiting factor. We do store extents in the form
2554  * of starting block and length, hence the resulting length of the extent
2555  * covering maximum file size must fit into on-disk format containers as
2556  * well. Given that length is always by 1 unit bigger than max unit (because
2557  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2558  *
2559  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2560  */
2561 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2562 {
2563         loff_t res;
2564         loff_t upper_limit = MAX_LFS_FILESIZE;
2565 
2566         /* small i_blocks in vfs inode? */
2567         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2568                 /*
2569                  * CONFIG_LBDAF is not enabled implies the inode
2570                  * i_block represent total blocks in 512 bytes
2571                  * 32 == size of vfs inode i_blocks * 8
2572                  */
2573                 upper_limit = (1LL << 32) - 1;
2574 
2575                 /* total blocks in file system block size */
2576                 upper_limit >>= (blkbits - 9);
2577                 upper_limit <<= blkbits;
2578         }
2579 
2580         /*
2581          * 32-bit extent-start container, ee_block. We lower the maxbytes
2582          * by one fs block, so ee_len can cover the extent of maximum file
2583          * size
2584          */
2585         res = (1LL << 32) - 1;
2586         res <<= blkbits;
2587 
2588         /* Sanity check against vm- & vfs- imposed limits */
2589         if (res > upper_limit)
2590                 res = upper_limit;
2591 
2592         return res;
2593 }
2594 
2595 /*
2596  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2597  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2598  * We need to be 1 filesystem block less than the 2^48 sector limit.
2599  */
2600 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2601 {
2602         loff_t res = EXT4_NDIR_BLOCKS;
2603         int meta_blocks;
2604         loff_t upper_limit;
2605         /* This is calculated to be the largest file size for a dense, block
2606          * mapped file such that the file's total number of 512-byte sectors,
2607          * including data and all indirect blocks, does not exceed (2^48 - 1).
2608          *
2609          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2610          * number of 512-byte sectors of the file.
2611          */
2612 
2613         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2614                 /*
2615                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2616                  * the inode i_block field represents total file blocks in
2617                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2618                  */
2619                 upper_limit = (1LL << 32) - 1;
2620 
2621                 /* total blocks in file system block size */
2622                 upper_limit >>= (bits - 9);
2623 
2624         } else {
2625                 /*
2626                  * We use 48 bit ext4_inode i_blocks
2627                  * With EXT4_HUGE_FILE_FL set the i_blocks
2628                  * represent total number of blocks in
2629                  * file system block size
2630                  */
2631                 upper_limit = (1LL << 48) - 1;
2632 
2633         }
2634 
2635         /* indirect blocks */
2636         meta_blocks = 1;
2637         /* double indirect blocks */
2638         meta_blocks += 1 + (1LL << (bits-2));
2639         /* tripple indirect blocks */
2640         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2641 
2642         upper_limit -= meta_blocks;
2643         upper_limit <<= bits;
2644 
2645         res += 1LL << (bits-2);
2646         res += 1LL << (2*(bits-2));
2647         res += 1LL << (3*(bits-2));
2648         res <<= bits;
2649         if (res > upper_limit)
2650                 res = upper_limit;
2651 
2652         if (res > MAX_LFS_FILESIZE)
2653                 res = MAX_LFS_FILESIZE;
2654 
2655         return res;
2656 }
2657 
2658 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2659                                    ext4_fsblk_t logical_sb_block, int nr)
2660 {
2661         struct ext4_sb_info *sbi = EXT4_SB(sb);
2662         ext4_group_t bg, first_meta_bg;
2663         int has_super = 0;
2664 
2665         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2666 
2667         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2668                 return logical_sb_block + nr + 1;
2669         bg = sbi->s_desc_per_block * nr;
2670         if (ext4_bg_has_super(sb, bg))
2671                 has_super = 1;
2672 
2673         /*
2674          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2675          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2676          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2677          * compensate.
2678          */
2679         if (sb->s_blocksize == 1024 && nr == 0 &&
2680             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2681                 has_super++;
2682 
2683         return (has_super + ext4_group_first_block_no(sb, bg));
2684 }
2685 
2686 /**
2687  * ext4_get_stripe_size: Get the stripe size.
2688  * @sbi: In memory super block info
2689  *
2690  * If we have specified it via mount option, then
2691  * use the mount option value. If the value specified at mount time is
2692  * greater than the blocks per group use the super block value.
2693  * If the super block value is greater than blocks per group return 0.
2694  * Allocator needs it be less than blocks per group.
2695  *
2696  */
2697 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2698 {
2699         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2700         unsigned long stripe_width =
2701                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2702         int ret;
2703 
2704         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2705                 ret = sbi->s_stripe;
2706         else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2707                 ret = stripe_width;
2708         else if (stride && stride <= sbi->s_blocks_per_group)
2709                 ret = stride;
2710         else
2711                 ret = 0;
2712 
2713         /*
2714          * If the stripe width is 1, this makes no sense and
2715          * we set it to 0 to turn off stripe handling code.
2716          */
2717         if (ret <= 1)
2718                 ret = 0;
2719 
2720         return ret;
2721 }
2722 
2723 /*
2724  * Check whether this filesystem can be mounted based on
2725  * the features present and the RDONLY/RDWR mount requested.
2726  * Returns 1 if this filesystem can be mounted as requested,
2727  * 0 if it cannot be.
2728  */
2729 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2730 {
2731         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2732                 ext4_msg(sb, KERN_ERR,
2733                         "Couldn't mount because of "
2734                         "unsupported optional features (%x)",
2735                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2736                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2737                 return 0;
2738         }
2739 
2740         if (readonly)
2741                 return 1;
2742 
2743         if (ext4_has_feature_readonly(sb)) {
2744                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2745                 sb->s_flags |= SB_RDONLY;
2746                 return 1;
2747         }
2748 
2749         /* Check that feature set is OK for a read-write mount */
2750         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2751                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2752                          "unsupported optional features (%x)",
2753                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2754                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2755                 return 0;
2756         }
2757         /*
2758          * Large file size enabled file system can only be mounted
2759          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2760          */
2761         if (ext4_has_feature_huge_file(sb)) {
2762                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2763                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2764                                  "cannot be mounted RDWR without "
2765                                  "CONFIG_LBDAF");
2766                         return 0;
2767                 }
2768         }
2769         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2770                 ext4_msg(sb, KERN_ERR,
2771                          "Can't support bigalloc feature without "
2772                          "extents feature\n");
2773                 return 0;
2774         }
2775 
2776 #ifndef CONFIG_QUOTA
2777         if (ext4_has_feature_quota(sb) && !readonly) {
2778                 ext4_msg(sb, KERN_ERR,
2779                          "Filesystem with quota feature cannot be mounted RDWR "
2780                          "without CONFIG_QUOTA");
2781                 return 0;
2782         }
2783         if (ext4_has_feature_project(sb) && !readonly) {
2784                 ext4_msg(sb, KERN_ERR,
2785                          "Filesystem with project quota feature cannot be mounted RDWR "
2786                          "without CONFIG_QUOTA");
2787                 return 0;
2788         }
2789 #endif  /* CONFIG_QUOTA */
2790         return 1;
2791 }
2792 
2793 /*
2794  * This function is called once a day if we have errors logged
2795  * on the file system
2796  */
2797 static void print_daily_error_info(struct timer_list *t)
2798 {
2799         struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2800         struct super_block *sb = sbi->s_sb;
2801         struct ext4_super_block *es = sbi->s_es;
2802 
2803         if (es->s_error_count)
2804                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2805                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2806                          le32_to_cpu(es->s_error_count));
2807         if (es->s_first_error_time) {
2808                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2809                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2810                        (int) sizeof(es->s_first_error_func),
2811                        es->s_first_error_func,
2812                        le32_to_cpu(es->s_first_error_line));
2813                 if (es->s_first_error_ino)
2814                         printk(KERN_CONT ": inode %u",
2815                                le32_to_cpu(es->s_first_error_ino));
2816                 if (es->s_first_error_block)
2817                         printk(KERN_CONT ": block %llu", (unsigned long long)
2818                                le64_to_cpu(es->s_first_error_block));
2819                 printk(KERN_CONT "\n");
2820         }
2821         if (es->s_last_error_time) {
2822                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2823                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2824                        (int) sizeof(es->s_last_error_func),
2825                        es->s_last_error_func,
2826                        le32_to_cpu(es->s_last_error_line));
2827                 if (es->s_last_error_ino)
2828                         printk(KERN_CONT ": inode %u",
2829                                le32_to_cpu(es->s_last_error_ino));
2830                 if (es->s_last_error_block)
2831                         printk(KERN_CONT ": block %llu", (unsigned long long)
2832                                le64_to_cpu(es->s_last_error_block));
2833                 printk(KERN_CONT "\n");
2834         }
2835         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2836 }
2837 
2838 /* Find next suitable group and run ext4_init_inode_table */
2839 static int ext4_run_li_request(struct ext4_li_request *elr)
2840 {
2841         struct ext4_group_desc *gdp = NULL;
2842         ext4_group_t group, ngroups;
2843         struct super_block *sb;
2844         unsigned long timeout = 0;
2845         int ret = 0;
2846 
2847         sb = elr->lr_super;
2848         ngroups = EXT4_SB(sb)->s_groups_count;
2849 
2850         for (group = elr->lr_next_group; group < ngroups; group++) {
2851                 gdp = ext4_get_group_desc(sb, group, NULL);
2852                 if (!gdp) {
2853                         ret = 1;
2854                         break;
2855                 }
2856 
2857                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2858                         break;
2859         }
2860 
2861         if (group >= ngroups)
2862                 ret = 1;
2863 
2864         if (!ret) {
2865                 timeout = jiffies;
2866                 ret = ext4_init_inode_table(sb, group,
2867                                             elr->lr_timeout ? 0 : 1);
2868                 if (elr->lr_timeout == 0) {
2869                         timeout = (jiffies - timeout) *
2870                                   elr->lr_sbi->s_li_wait_mult;
2871                         elr->lr_timeout = timeout;
2872                 }
2873                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2874                 elr->lr_next_group = group + 1;
2875         }
2876         return ret;
2877 }
2878 
2879 /*
2880  * Remove lr_request from the list_request and free the
2881  * request structure. Should be called with li_list_mtx held
2882  */
2883 static void ext4_remove_li_request(struct ext4_li_request *elr)
2884 {
2885         struct ext4_sb_info *sbi;
2886 
2887         if (!elr)
2888                 return;
2889 
2890         sbi = elr->lr_sbi;
2891 
2892         list_del(&elr->lr_request);
2893         sbi->s_li_request = NULL;
2894         kfree(elr);
2895 }
2896 
2897 static void ext4_unregister_li_request(struct super_block *sb)
2898 {
2899         mutex_lock(&ext4_li_mtx);
2900         if (!ext4_li_info) {
2901                 mutex_unlock(&ext4_li_mtx);
2902                 return;
2903         }
2904 
2905         mutex_lock(&ext4_li_info->li_list_mtx);
2906         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2907         mutex_unlock(&ext4_li_info->li_list_mtx);
2908         mutex_unlock(&ext4_li_mtx);
2909 }
2910 
2911 static struct task_struct *ext4_lazyinit_task;
2912 
2913 /*
2914  * This is the function where ext4lazyinit thread lives. It walks
2915  * through the request list searching for next scheduled filesystem.
2916  * When such a fs is found, run the lazy initialization request
2917  * (ext4_rn_li_request) and keep track of the time spend in this
2918  * function. Based on that time we compute next schedule time of
2919  * the request. When walking through the list is complete, compute
2920  * next waking time and put itself into sleep.
2921  */
2922 static int ext4_lazyinit_thread(void *arg)
2923 {
2924         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2925         struct list_head *pos, *n;
2926         struct ext4_li_request *elr;
2927         unsigned long next_wakeup, cur;
2928 
2929         BUG_ON(NULL == eli);
2930 
2931 cont_thread:
2932         while (true) {
2933                 next_wakeup = MAX_JIFFY_OFFSET;
2934 
2935                 mutex_lock(&eli->li_list_mtx);
2936                 if (list_empty(&eli->li_request_list)) {
2937                         mutex_unlock(&eli->li_list_mtx);
2938                         goto exit_thread;
2939                 }
2940                 list_for_each_safe(pos, n, &eli->li_request_list) {
2941                         int err = 0;
2942                         int progress = 0;
2943                         elr = list_entry(pos, struct ext4_li_request,
2944                                          lr_request);
2945 
2946                         if (time_before(jiffies, elr->lr_next_sched)) {
2947                                 if (time_before(elr->lr_next_sched, next_wakeup))
2948                                         next_wakeup = elr->lr_next_sched;
2949                                 continue;
2950                         }
2951                         if (down_read_trylock(&elr->lr_super->s_umount)) {
2952                                 if (sb_start_write_trylock(elr->lr_super)) {
2953                                         progress = 1;
2954                                         /*
2955                                          * We hold sb->s_umount, sb can not
2956                                          * be removed from the list, it is
2957                                          * now safe to drop li_list_mtx
2958                                          */
2959                                         mutex_unlock(&eli->li_list_mtx);
2960                                         err = ext4_run_li_request(elr);
2961                                         sb_end_write(elr->lr_super);
2962                                         mutex_lock(&eli->li_list_mtx);
2963                                         n = pos->next;
2964                                 }
2965                                 up_read((&elr->lr_super->s_umount));
2966                         }
2967                         /* error, remove the lazy_init job */
2968                         if (err) {
2969                                 ext4_remove_li_request(elr);
2970                                 continue;
2971                         }
2972                         if (!progress) {
2973                                 elr->lr_next_sched = jiffies +
2974                                         (prandom_u32()
2975                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2976                         }
2977                         if (time_before(elr->lr_next_sched, next_wakeup))
2978                                 next_wakeup = elr->lr_next_sched;
2979                 }
2980                 mutex_unlock(&eli->li_list_mtx);
2981 
2982                 try_to_freeze();
2983 
2984                 cur = jiffies;
2985                 if ((time_after_eq(cur, next_wakeup)) ||
2986                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2987                         cond_resched();
2988                         continue;
2989                 }
2990 
2991                 schedule_timeout_interruptible(next_wakeup - cur);
2992 
2993                 if (kthread_should_stop()) {
2994                         ext4_clear_request_list();
2995                         goto exit_thread;
2996                 }
2997         }
2998 
2999 exit_thread:
3000         /*
3001          * It looks like the request list is empty, but we need
3002          * to check it under the li_list_mtx lock, to prevent any
3003          * additions into it, and of course we should lock ext4_li_mtx
3004          * to atomically free the list and ext4_li_info, because at
3005          * this point another ext4 filesystem could be registering
3006          * new one.
3007          */
3008         mutex_lock(&ext4_li_mtx);
3009         mutex_lock(&eli->li_list_mtx);
3010         if (!list_empty(&eli->li_request_list)) {
3011                 mutex_unlock(&eli->li_list_mtx);
3012                 mutex_unlock(&ext4_li_mtx);
3013                 goto cont_thread;
3014         }
3015         mutex_unlock(&eli->li_list_mtx);
3016         kfree(ext4_li_info);
3017         ext4_li_info = NULL;
3018         mutex_unlock(&ext4_li_mtx);
3019 
3020         return 0;
3021 }
3022 
3023 static void ext4_clear_request_list(void)
3024 {
3025         struct list_head *pos, *n;
3026         struct ext4_li_request *elr;
3027 
3028         mutex_lock(&ext4_li_info->li_list_mtx);
3029         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3030                 elr = list_entry(pos, struct ext4_li_request,
3031                                  lr_request);
3032                 ext4_remove_li_request(elr);
3033         }
3034         mutex_unlock(&ext4_li_info->li_list_mtx);
3035 }
3036 
3037 static int ext4_run_lazyinit_thread(void)
3038 {
3039         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3040                                          ext4_li_info, "ext4lazyinit");
3041         if (IS_ERR(ext4_lazyinit_task)) {
3042                 int err = PTR_ERR(ext4_lazyinit_task);
3043                 ext4_clear_request_list();
3044                 kfree(ext4_li_info);
3045                 ext4_li_info = NULL;
3046                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3047                                  "initialization thread\n",
3048                                  err);
3049                 return err;
3050         }
3051         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3052         return 0;
3053 }
3054 
3055 /*
3056  * Check whether it make sense to run itable init. thread or not.
3057  * If there is at least one uninitialized inode table, return
3058  * corresponding group number, else the loop goes through all
3059  * groups and return total number of groups.
3060  */
3061 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3062 {
3063         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3064         struct ext4_group_desc *gdp = NULL;
3065 
3066         for (group = 0; group < ngroups; group++) {
3067                 gdp = ext4_get_group_desc(sb, group, NULL);
3068                 if (!gdp)
3069                         continue;
3070 
3071                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3072                         break;
3073         }
3074 
3075         return group;
3076 }
3077 
3078 static int ext4_li_info_new(void)
3079 {
3080         struct ext4_lazy_init *eli = NULL;
3081 
3082         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3083         if (!eli)
3084                 return -ENOMEM;
3085 
3086         INIT_LIST_HEAD(&eli->li_request_list);
3087         mutex_init(&eli->li_list_mtx);
3088 
3089         eli->li_state |= EXT4_LAZYINIT_QUIT;
3090 
3091         ext4_li_info = eli;
3092 
3093         return 0;
3094 }
3095 
3096 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3097                                             ext4_group_t start)
3098 {
3099         struct ext4_sb_info *sbi = EXT4_SB(sb);
3100         struct ext4_li_request *elr;
3101 
3102         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3103         if (!elr)
3104                 return NULL;
3105 
3106         elr->lr_super = sb;
3107         elr->lr_sbi = sbi;
3108         elr->lr_next_group = start;
3109 
3110         /*
3111          * Randomize first schedule time of the request to
3112          * spread the inode table initialization requests
3113          * better.
3114          */
3115         elr->lr_next_sched = jiffies + (prandom_u32() %
3116                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3117         return elr;
3118 }
3119 
3120 int ext4_register_li_request(struct super_block *sb,
3121                              ext4_group_t first_not_zeroed)
3122 {
3123         struct ext4_sb_info *sbi = EXT4_SB(sb);
3124         struct ext4_li_request *elr = NULL;
3125         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3126         int ret = 0;
3127 
3128         mutex_lock(&ext4_li_mtx);
3129         if (sbi->s_li_request != NULL) {
3130                 /*
3131                  * Reset timeout so it can be computed again, because
3132                  * s_li_wait_mult might have changed.
3133                  */
3134                 sbi->s_li_request->lr_timeout = 0;
3135                 goto out;
3136         }
3137 
3138         if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3139             !test_opt(sb, INIT_INODE_TABLE))
3140                 goto out;
3141 
3142         elr = ext4_li_request_new(sb, first_not_zeroed);
3143         if (!elr) {
3144                 ret = -ENOMEM;
3145                 goto out;
3146         }
3147 
3148         if (NULL == ext4_li_info) {
3149                 ret = ext4_li_info_new();
3150                 if (ret)
3151                         goto out;
3152         }
3153 
3154         mutex_lock(&ext4_li_info->li_list_mtx);
3155         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3156         mutex_unlock(&ext4_li_info->li_list_mtx);
3157 
3158         sbi->s_li_request = elr;
3159         /*
3160          * set elr to NULL here since it has been inserted to
3161          * the request_list and the removal and free of it is
3162          * handled by ext4_clear_request_list from now on.
3163          */
3164         elr = NULL;
3165 
3166         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3167                 ret = ext4_run_lazyinit_thread();
3168                 if (ret)
3169                         goto out;
3170         }
3171 out:
3172         mutex_unlock(&ext4_li_mtx);
3173         if (ret)
3174                 kfree(elr);
3175         return ret;
3176 }
3177 
3178 /*
3179  * We do not need to lock anything since this is called on
3180  * module unload.
3181  */
3182 static void ext4_destroy_lazyinit_thread(void)
3183 {
3184         /*
3185          * If thread exited earlier
3186          * there's nothing to be done.
3187          */
3188         if (!ext4_li_info || !ext4_lazyinit_task)
3189                 return;
3190 
3191         kthread_stop(ext4_lazyinit_task);
3192 }
3193 
3194 static int set_journal_csum_feature_set(struct super_block *sb)
3195 {
3196         int ret = 1;
3197         int compat, incompat;
3198         struct ext4_sb_info *sbi = EXT4_SB(sb);
3199 
3200         if (ext4_has_metadata_csum(sb)) {
3201                 /* journal checksum v3 */
3202                 compat = 0;
3203                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3204         } else {
3205                 /* journal checksum v1 */
3206                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3207                 incompat = 0;
3208         }
3209 
3210         jbd2_journal_clear_features(sbi->s_journal,
3211                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3212                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3213                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3214         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3215                 ret = jbd2_journal_set_features(sbi->s_journal,
3216                                 compat, 0,
3217                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3218                                 incompat);
3219         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3220                 ret = jbd2_journal_set_features(sbi->s_journal,
3221                                 compat, 0,
3222                                 incompat);
3223                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3224                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3225         } else {
3226                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3227                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3228         }
3229 
3230         return ret;
3231 }
3232 
3233 /*
3234  * Note: calculating the overhead so we can be compatible with
3235  * historical BSD practice is quite difficult in the face of
3236  * clusters/bigalloc.  This is because multiple metadata blocks from
3237  * different block group can end up in the same allocation cluster.
3238  * Calculating the exact overhead in the face of clustered allocation
3239  * requires either O(all block bitmaps) in memory or O(number of block
3240  * groups**2) in time.  We will still calculate the superblock for
3241  * older file systems --- and if we come across with a bigalloc file
3242  * system with zero in s_overhead_clusters the estimate will be close to
3243  * correct especially for very large cluster sizes --- but for newer
3244  * file systems, it's better to calculate this figure once at mkfs
3245  * time, and store it in the superblock.  If the superblock value is
3246  * present (even for non-bigalloc file systems), we will use it.
3247  */
3248 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3249                           char *buf)
3250 {
3251         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3252         struct ext4_group_desc  *gdp;
3253         ext4_fsblk_t            first_block, last_block, b;
3254         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3255         int                     s, j, count = 0;
3256 
3257         if (!ext4_has_feature_bigalloc(sb))
3258                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3259                         sbi->s_itb_per_group + 2);
3260 
3261         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3262                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3263         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3264         for (i = 0; i < ngroups; i++) {
3265                 gdp = ext4_get_group_desc(sb, i, NULL);
3266                 b = ext4_block_bitmap(sb, gdp);
3267                 if (b >= first_block && b <= last_block) {
3268                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3269                         count++;
3270                 }
3271                 b = ext4_inode_bitmap(sb, gdp);
3272                 if (b >= first_block && b <= last_block) {
3273                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3274                         count++;
3275                 }
3276                 b = ext4_inode_table(sb, gdp);
3277                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3278                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3279                                 int c = EXT4_B2C(sbi, b - first_block);
3280                                 ext4_set_bit(c, buf);
3281                                 count++;
3282                         }
3283                 if (i != grp)
3284                         continue;
3285                 s = 0;
3286                 if (ext4_bg_has_super(sb, grp)) {
3287                         ext4_set_bit(s++, buf);
3288                         count++;
3289                 }
3290                 j = ext4_bg_num_gdb(sb, grp);
3291                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3292                         ext4_error(sb, "Invalid number of block group "
3293                                    "descriptor blocks: %d", j);
3294                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3295                 }
3296                 count += j;
3297                 for (; j > 0; j--)
3298                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3299         }
3300         if (!count)
3301                 return 0;
3302         return EXT4_CLUSTERS_PER_GROUP(sb) -
3303                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3304 }
3305 
3306 /*
3307  * Compute the overhead and stash it in sbi->s_overhead
3308  */
3309 int ext4_calculate_overhead(struct super_block *sb)
3310 {
3311         struct ext4_sb_info *sbi = EXT4_SB(sb);
3312         struct ext4_super_block *es = sbi->s_es;
3313         struct inode *j_inode;
3314         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3315         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3316         ext4_fsblk_t overhead = 0;
3317         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3318 
3319         if (!buf)
3320                 return -ENOMEM;
3321 
3322         /*
3323          * Compute the overhead (FS structures).  This is constant
3324          * for a given filesystem unless the number of block groups
3325          * changes so we cache the previous value until it does.
3326          */
3327 
3328         /*
3329          * All of the blocks before first_data_block are overhead
3330          */
3331         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3332 
3333         /*
3334          * Add the overhead found in each block group
3335          */
3336         for (i = 0; i < ngroups; i++) {
3337                 int blks;
3338 
3339                 blks = count_overhead(sb, i, buf);
3340                 overhead += blks;
3341                 if (blks)
3342                         memset(buf, 0, PAGE_SIZE);
3343                 cond_resched();
3344         }
3345 
3346         /*
3347          * Add the internal journal blocks whether the journal has been
3348          * loaded or not
3349          */
3350         if (sbi->s_journal && !sbi->journal_bdev)
3351                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3352         else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3353                 j_inode = ext4_get_journal_inode(sb, j_inum);
3354                 if (j_inode) {
3355                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3356                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
3357                         iput(j_inode);
3358                 } else {
3359                         ext4_msg(sb, KERN_ERR, "can't get journal size");
3360                 }
3361         }
3362         sbi->s_overhead = overhead;
3363         smp_wmb();
3364         free_page((unsigned long) buf);
3365         return 0;
3366 }
3367 
3368 static void ext4_set_resv_clusters(struct super_block *sb)
3369 {
3370         ext4_fsblk_t resv_clusters;
3371         struct ext4_sb_info *sbi = EXT4_SB(sb);
3372 
3373         /*
3374          * There's no need to reserve anything when we aren't using extents.
3375          * The space estimates are exact, there are no unwritten extents,
3376          * hole punching doesn't need new metadata... This is needed especially
3377          * to keep ext2/3 backward compatibility.
3378          */
3379         if (!ext4_has_feature_extents(sb))
3380                 return;
3381         /*
3382          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3383          * This should cover the situations where we can not afford to run
3384          * out of space like for example punch hole, or converting
3385          * unwritten extents in delalloc path. In most cases such
3386          * allocation would require 1, or 2 blocks, higher numbers are
3387          * very rare.
3388          */
3389         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3390                          sbi->s_cluster_bits);
3391 
3392         do_div(resv_clusters, 50);
3393         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3394 
3395         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3396 }
3397 
3398 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3399 {
3400         struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3401         char *orig_data = kstrdup(data, GFP_KERNEL);
3402         struct buffer_head *bh;
3403         struct ext4_super_block *es = NULL;
3404         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3405         ext4_fsblk_t block;
3406         ext4_fsblk_t sb_block = get_sb_block(&data);
3407         ext4_fsblk_t logical_sb_block;
3408         unsigned long offset = 0;
3409         unsigned long journal_devnum = 0;
3410         unsigned long def_mount_opts;
3411         struct inode *root;
3412         const char *descr;
3413         int ret = -ENOMEM;
3414         int blocksize, clustersize;
3415         unsigned int db_count;
3416         unsigned int i;
3417         int needs_recovery, has_huge_files, has_bigalloc;
3418         __u64 blocks_count;
3419         int err = 0;
3420         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3421         ext4_group_t first_not_zeroed;
3422 
3423         if ((data && !orig_data) || !sbi)
3424                 goto out_free_base;
3425 
3426         sbi->s_daxdev = dax_dev;
3427         sbi->s_blockgroup_lock =
3428                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3429         if (!sbi->s_blockgroup_lock)
3430                 goto out_free_base;
3431 
3432         sb->s_fs_info = sbi;
3433         sbi->s_sb = sb;
3434         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3435         sbi->s_sb_block = sb_block;
3436         if (sb->s_bdev->bd_part)
3437                 sbi->s_sectors_written_start =
3438                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3439 
3440         /* Cleanup superblock name */
3441         strreplace(sb->s_id, '/', '!');
3442 
3443         /* -EINVAL is default */
3444         ret = -EINVAL;
3445         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3446         if (!blocksize) {
3447                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3448                 goto out_fail;
3449         }
3450 
3451         /*
3452          * The ext4 superblock will not be buffer aligned for other than 1kB
3453          * block sizes.  We need to calculate the offset from buffer start.
3454          */
3455         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3456                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3457                 offset = do_div(logical_sb_block, blocksize);
3458         } else {
3459                 logical_sb_block = sb_block;
3460         }
3461 
3462         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3463                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3464                 goto out_fail;
3465         }
3466         /*
3467          * Note: s_es must be initialized as soon as possible because
3468          *       some ext4 macro-instructions depend on its value
3469          */
3470         es = (struct ext4_super_block *) (bh->b_data + offset);
3471         sbi->s_es = es;
3472         sb->s_magic = le16_to_cpu(es->s_magic);
3473         if (sb->s_magic != EXT4_SUPER_MAGIC)
3474                 goto cantfind_ext4;
3475         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3476 
3477         /* Warn if metadata_csum and gdt_csum are both set. */
3478         if (ext4_has_feature_metadata_csum(sb) &&
3479             ext4_has_feature_gdt_csum(sb))
3480                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3481                              "redundant flags; please run fsck.");
3482 
3483         /* Check for a known checksum algorithm */
3484         if (!ext4_verify_csum_type(sb, es)) {
3485                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3486                          "unknown checksum algorithm.");
3487                 silent = 1;
3488                 goto cantfind_ext4;
3489         }
3490 
3491         /* Load the checksum driver */
3492         if (ext4_has_feature_metadata_csum(sb) ||
3493             ext4_has_feature_ea_inode(sb)) {
3494                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3495                 if (IS_ERR(sbi->s_chksum_driver)) {
3496                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3497                         ret = PTR_ERR(sbi->s_chksum_driver);
3498                         sbi->s_chksum_driver = NULL;
3499                         goto failed_mount;
3500                 }
3501         }
3502 
3503         /* Check superblock checksum */
3504         if (!ext4_superblock_csum_verify(sb, es)) {
3505                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3506                          "invalid superblock checksum.  Run e2fsck?");
3507                 silent = 1;
3508                 ret = -EFSBADCRC;
3509                 goto cantfind_ext4;
3510         }
3511 
3512         /* Precompute checksum seed for all metadata */
3513         if (ext4_has_feature_csum_seed(sb))
3514                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3515         else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3516                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3517                                                sizeof(es->s_uuid));
3518 
3519         /* Set defaults before we parse the mount options */
3520         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3521         set_opt(sb, INIT_INODE_TABLE);
3522         if (def_mount_opts & EXT4_DEFM_DEBUG)
3523                 set_opt(sb, DEBUG);
3524         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3525                 set_opt(sb, GRPID);
3526         if (def_mount_opts & EXT4_DEFM_UID16)
3527                 set_opt(sb, NO_UID32);
3528         /* xattr user namespace & acls are now defaulted on */
3529         set_opt(sb, XATTR_USER);
3530 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3531         set_opt(sb, POSIX_ACL);
3532 #endif
3533         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3534         if (ext4_has_metadata_csum(sb))
3535                 set_opt(sb, JOURNAL_CHECKSUM);
3536 
3537         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3538                 set_opt(sb, JOURNAL_DATA);
3539         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3540                 set_opt(sb, ORDERED_DATA);
3541         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3542                 set_opt(sb, WRITEBACK_DATA);
3543 
3544         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3545                 set_opt(sb, ERRORS_PANIC);
3546         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3547                 set_opt(sb, ERRORS_CONT);
3548         else
3549                 set_opt(sb, ERRORS_RO);
3550         /* block_validity enabled by default; disable with noblock_validity */
3551         set_opt(sb, BLOCK_VALIDITY);
3552         if (def_mount_opts & EXT4_DEFM_DISCARD)
3553                 set_opt(sb, DISCARD);
3554 
3555         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3556         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3557         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3558         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3559         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3560 
3561         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3562                 set_opt(sb, BARRIER);
3563 
3564         /*
3565          * enable delayed allocation by default
3566          * Use -o nodelalloc to turn it off
3567          */
3568         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3569             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3570                 set_opt(sb, DELALLOC);
3571 
3572         /*
3573          * set default s_li_wait_mult for lazyinit, for the case there is
3574          * no mount option specified.
3575          */
3576         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3577 
3578         if (sbi->s_es->s_mount_opts[0]) {
3579                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3580                                               sizeof(sbi->s_es->s_mount_opts),
3581                                               GFP_KERNEL);
3582                 if (!s_mount_opts)
3583                         goto failed_mount;
3584                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3585                                    &journal_ioprio, 0)) {
3586                         ext4_msg(sb, KERN_WARNING,
3587                                  "failed to parse options in superblock: %s",
3588                                  s_mount_opts);
3589                 }
3590                 kfree(s_mount_opts);
3591         }
3592         sbi->s_def_mount_opt = sbi->s_mount_opt;
3593         if (!parse_options((char *) data, sb, &journal_devnum,
3594                            &journal_ioprio, 0))
3595                 goto failed_mount;
3596 
3597         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3598                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3599                             "with data=journal disables delayed "
3600                             "allocation and O_DIRECT support!\n");
3601                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3602                         ext4_msg(sb, KERN_ERR, "can't mount with "
3603                                  "both data=journal and delalloc");
3604                         goto failed_mount;
3605                 }
3606                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3607                         ext4_msg(sb, KERN_ERR, "can't mount with "
3608                                  "both data=journal and dioread_nolock");
3609                         goto failed_mount;
3610                 }
3611                 if (test_opt(sb, DAX)) {
3612                         ext4_msg(sb, KERN_ERR, "can't mount with "
3613                                  "both data=journal and dax");
3614                         goto failed_mount;
3615                 }
3616                 if (ext4_has_feature_encrypt(sb)) {
3617                         ext4_msg(sb, KERN_WARNING,
3618                                  "encrypted files will use data=ordered "
3619                                  "instead of data journaling mode");
3620                 }
3621                 if (test_opt(sb, DELALLOC))
3622                         clear_opt(sb, DELALLOC);
3623         } else {
3624                 sb->s_iflags |= SB_I_CGROUPWB;
3625         }
3626 
3627         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3628                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3629 
3630         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3631             (ext4_has_compat_features(sb) ||
3632              ext4_has_ro_compat_features(sb) ||
3633              ext4_has_incompat_features(sb)))
3634                 ext4_msg(sb, KERN_WARNING,
3635                        "feature flags set on rev 0 fs, "
3636                        "running e2fsck is recommended");
3637 
3638         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3639                 set_opt2(sb, HURD_COMPAT);
3640                 if (ext4_has_feature_64bit(sb)) {
3641                         ext4_msg(sb, KERN_ERR,
3642                                  "The Hurd can't support 64-bit file systems");
3643                         goto failed_mount;
3644                 }
3645 
3646                 /*
3647                  * ea_inode feature uses l_i_version field which is not
3648                  * available in HURD_COMPAT mode.
3649                  */
3650                 if (ext4_has_feature_ea_inode(sb)) {
3651                         ext4_msg(sb, KERN_ERR,
3652                                  "ea_inode feature is not supported for Hurd");
3653                         goto failed_mount;
3654                 }
3655         }
3656 
3657         if (IS_EXT2_SB(sb)) {
3658                 if (ext2_feature_set_ok(sb))
3659                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3660                                  "using the ext4 subsystem");
3661                 else {
3662                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3663                                  "to feature incompatibilities");
3664                         goto failed_mount;
3665                 }
3666         }
3667 
3668         if (IS_EXT3_SB(sb)) {
3669                 if (ext3_feature_set_ok(sb))
3670                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3671                                  "using the ext4 subsystem");
3672                 else {
3673                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3674                                  "to feature incompatibilities");
3675                         goto failed_mount;
3676                 }
3677         }
3678 
3679         /*
3680          * Check feature flags regardless of the revision level, since we
3681          * previously didn't change the revision level when setting the flags,
3682          * so there is a chance incompat flags are set on a rev 0 filesystem.
3683          */
3684         if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3685                 goto failed_mount;
3686 
3687         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3688         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3689             blocksize > EXT4_MAX_BLOCK_SIZE) {
3690                 ext4_msg(sb, KERN_ERR,
3691                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3692                          blocksize, le32_to_cpu(es->s_log_block_size));
3693                 goto failed_mount;
3694         }
3695         if (le32_to_cpu(es->s_log_block_size) >
3696             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3697                 ext4_msg(sb, KERN_ERR,
3698                          "Invalid log block size: %u",
3699                          le32_to_cpu(es->s_log_block_size));
3700                 goto failed_mount;
3701         }
3702 
3703         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3704                 ext4_msg(sb, KERN_ERR,
3705                          "Number of reserved GDT blocks insanely large: %d",
3706                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3707                 goto failed_mount;
3708         }
3709 
3710         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3711                 if (ext4_has_feature_inline_data(sb)) {
3712                         ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3713                                         " that may contain inline data");
3714                         goto failed_mount;
3715                 }
3716                 err = bdev_dax_supported(sb, blocksize);
3717                 if (err)
3718                         goto failed_mount;
3719         }
3720 
3721         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3722                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3723                          es->s_encryption_level);
3724                 goto failed_mount;
3725         }
3726 
3727         if (sb->s_blocksize != blocksize) {
3728                 /* Validate the filesystem blocksize */
3729                 if (!sb_set_blocksize(sb, blocksize)) {
3730                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3731                                         blocksize);
3732                         goto failed_mount;
3733                 }
3734 
3735                 brelse(bh);
3736                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3737                 offset = do_div(logical_sb_block, blocksize);
3738                 bh = sb_bread_unmovable(sb, logical_sb_block);
3739                 if (!bh) {
3740                         ext4_msg(sb, KERN_ERR,
3741                                "Can't read superblock on 2nd try");
3742                         goto failed_mount;
3743                 }
3744                 es = (struct ext4_super_block *)(bh->b_data + offset);
3745                 sbi->s_es = es;
3746                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3747                         ext4_msg(sb, KERN_ERR,
3748                                "Magic mismatch, very weird!");
3749                         goto failed_mount;
3750                 }
3751         }
3752 
3753         has_huge_files = ext4_has_feature_huge_file(sb);
3754         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3755                                                       has_huge_files);
3756         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3757 
3758         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3759                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3760                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3761         } else {
3762                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3763                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3764                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3765                     (!is_power_of_2(sbi->s_inode_size)) ||
3766                     (sbi->s_inode_size > blocksize)) {
3767                         ext4_msg(sb, KERN_ERR,
3768                                "unsupported inode size: %d",
3769                                sbi->s_inode_size);
3770                         goto failed_mount;
3771                 }
3772                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3773                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3774         }
3775 
3776         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3777         if (ext4_has_feature_64bit(sb)) {
3778                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3779                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3780                     !is_power_of_2(sbi->s_desc_size)) {
3781                         ext4_msg(sb, KERN_ERR,
3782                                "unsupported descriptor size %lu",
3783                                sbi->s_desc_size);
3784                         goto failed_mount;
3785                 }
3786         } else
3787                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3788 
3789         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3790         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3791 
3792         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3793         if (sbi->s_inodes_per_block == 0)
3794                 goto cantfind_ext4;
3795         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3796             sbi->s_inodes_per_group > blocksize * 8) {
3797                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3798                          sbi->s_blocks_per_group);
3799                 goto failed_mount;
3800         }
3801         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3802                                         sbi->s_inodes_per_block;
3803         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3804         sbi->s_sbh = bh;
3805         sbi->s_mount_state = le16_to_cpu(es->s_state);
3806         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3807         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3808 
3809         for (i = 0; i < 4; i++)
3810                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3811         sbi->s_def_hash_version = es->s_def_hash_version;
3812         if (ext4_has_feature_dir_index(sb)) {
3813                 i = le32_to_cpu(es->s_flags);
3814                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3815                         sbi->s_hash_unsigned = 3;
3816                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3817 #ifdef __CHAR_UNSIGNED__
3818                         if (!sb_rdonly(sb))
3819                                 es->s_flags |=
3820                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3821                         sbi->s_hash_unsigned = 3;
3822 #else
3823                         if (!sb_rdonly(sb))
3824                                 es->s_flags |=
3825                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3826 #endif
3827                 }
3828         }
3829 
3830         /* Handle clustersize */
3831         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3832         has_bigalloc = ext4_has_feature_bigalloc(sb);
3833         if (has_bigalloc) {
3834                 if (clustersize < blocksize) {
3835                         ext4_msg(sb, KERN_ERR,
3836                                  "cluster size (%d) smaller than "
3837                                  "block size (%d)", clustersize, blocksize);
3838                         goto failed_mount;
3839                 }
3840                 if (le32_to_cpu(es->s_log_cluster_size) >
3841                     (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3842                         ext4_msg(sb, KERN_ERR,
3843                                  "Invalid log cluster size: %u",
3844                                  le32_to_cpu(es->s_log_cluster_size));
3845                         goto failed_mount;
3846                 }
3847                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3848                         le32_to_cpu(es->s_log_block_size);
3849                 sbi->s_clusters_per_group =
3850                         le32_to_cpu(es->s_clusters_per_group);
3851                 if (sbi->s_clusters_per_group > blocksize * 8) {
3852                         ext4_msg(sb, KERN_ERR,
3853                                  "#clusters per group too big: %lu",
3854                                  sbi->s_clusters_per_group);
3855                         goto failed_mount;
3856                 }
3857                 if (sbi->s_blocks_per_group !=
3858                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3859                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3860                                  "clusters per group (%lu) inconsistent",
3861                                  sbi->s_blocks_per_group,
3862                                  sbi->s_clusters_per_group);
3863                         goto failed_mount;
3864                 }
3865         } else {
3866                 if (clustersize != blocksize) {
3867                         ext4_warning(sb, "fragment/cluster size (%d) != "
3868                                      "block size (%d)", clustersize,
3869                                      blocksize);
3870                         clustersize = blocksize;
3871                 }
3872                 if (sbi->s_blocks_per_group > blocksize * 8) {
3873                         ext4_msg(sb, KERN_ERR,
3874                                  "#blocks per group too big: %lu",
3875                                  sbi->s_blocks_per_group);
3876                         goto failed_mount;
3877                 }
3878                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3879                 sbi->s_cluster_bits = 0;
3880         }
3881         sbi->s_cluster_ratio = clustersize / blocksize;
3882 
3883         /* Do we have standard group size of clustersize * 8 blocks ? */
3884         if (sbi->s_blocks_per_group == clustersize << 3)
3885                 set_opt2(sb, STD_GROUP_SIZE);
3886 
3887         /*
3888          * Test whether we have more sectors than will fit in sector_t,
3889          * and whether the max offset is addressable by the page cache.
3890          */
3891         err = generic_check_addressable(sb->s_blocksize_bits,
3892                                         ext4_blocks_count(es));
3893         if (err) {
3894                 ext4_msg(sb, KERN_ERR, "filesystem"
3895                          " too large to mount safely on this system");
3896                 if (sizeof(sector_t) < 8)
3897                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3898                 goto failed_mount;
3899         }
3900 
3901         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3902                 goto cantfind_ext4;
3903 
3904         /* check blocks count against device size */
3905         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3906         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3907                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3908                        "exceeds size of device (%llu blocks)",
3909                        ext4_blocks_count(es), blocks_count);
3910                 goto failed_mount;
3911         }
3912 
3913         /*
3914          * It makes no sense for the first data block to be beyond the end
3915          * of the filesystem.
3916          */
3917         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3918                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3919                          "block %u is beyond end of filesystem (%llu)",
3920                          le32_to_cpu(es->s_first_data_block),
3921                          ext4_blocks_count(es));
3922                 goto failed_mount;
3923         }
3924         blocks_count = (ext4_blocks_count(es) -
3925                         le32_to_cpu(es->s_first_data_block) +
3926                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3927         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3928         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3929                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3930                        "(block count %llu, first data block %u, "
3931                        "blocks per group %lu)", sbi->s_groups_count,
3932                        ext4_blocks_count(es),
3933                        le32_to_cpu(es->s_first_data_block),
3934                        EXT4_BLOCKS_PER_GROUP(sb));
3935                 goto failed_mount;
3936         }
3937         sbi->s_groups_count = blocks_count;
3938         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3939                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3940         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3941                    EXT4_DESC_PER_BLOCK(sb);
3942         if (ext4_has_feature_meta_bg(sb)) {
3943                 if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3944                         ext4_msg(sb, KERN_WARNING,
3945                                  "first meta block group too large: %u "
3946                                  "(group descriptor block count %u)",
3947                                  le32_to_cpu(es->s_first_meta_bg), db_count);
3948                         goto failed_mount;
3949                 }
3950         }
3951         sbi->s_group_desc = kvmalloc(db_count *
3952                                           sizeof(struct buffer_head *),
3953                                           GFP_KERNEL);
3954         if (sbi->s_group_desc == NULL) {
3955                 ext4_msg(sb, KERN_ERR, "not enough memory");
3956                 ret = -ENOMEM;
3957                 goto failed_mount;
3958         }
3959 
3960         bgl_lock_init(sbi->s_blockgroup_lock);
3961 
3962         /* Pre-read the descriptors into the buffer cache */
3963         for (i = 0; i < db_count; i++) {
3964                 block = descriptor_loc(sb, logical_sb_block, i);
3965                 sb_breadahead(sb, block);
3966         }
3967 
3968         for (i = 0; i < db_count; i++) {
3969                 block = descriptor_loc(sb, logical_sb_block, i);
3970                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3971                 if (!sbi->s_group_desc[i]) {
3972                         ext4_msg(sb, KERN_ERR,
3973                                "can't read group descriptor %d", i);
3974                         db_count = i;
3975                         goto failed_mount2;
3976                 }
3977         }
3978         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3979                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3980                 ret = -EFSCORRUPTED;
3981                 goto failed_mount2;
3982         }
3983 
3984         sbi->s_gdb_count = db_count;
3985 
3986         timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
3987 
3988         /* Register extent status tree shrinker */
3989         if (ext4_es_register_shrinker(sbi))
3990                 goto failed_mount3;
3991 
3992         sbi->s_stripe = ext4_get_stripe_size(sbi);
3993         sbi->s_extent_max_zeroout_kb = 32;
3994 
3995         /*
3996          * set up enough so that it can read an inode
3997          */
3998         sb->s_op = &ext4_sops;
3999         sb->s_export_op = &ext4_export_ops;
4000         sb->s_xattr = ext4_xattr_handlers;
4001 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4002         sb->s_cop = &ext4_cryptops;
4003 #endif
4004 #ifdef CONFIG_QUOTA
4005         sb->dq_op = &ext4_quota_operations;
4006         if (ext4_has_feature_quota(sb))
4007                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
4008         else
4009                 sb->s_qcop = &ext4_qctl_operations;
4010         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4011 #endif
4012         memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4013 
4014         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4015         mutex_init(&sbi->s_orphan_lock);
4016 
4017         sb->s_root = NULL;
4018 
4019         needs_recovery = (es->s_last_orphan != 0 ||
4020                           ext4_has_feature_journal_needs_recovery(sb));
4021 
4022         if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4023                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4024                         goto failed_mount3a;
4025 
4026         /*
4027          * The first inode we look at is the journal inode.  Don't try
4028          * root first: it may be modified in the journal!
4029          */
4030         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4031                 err = ext4_load_journal(sb, es, journal_devnum);
4032                 if (err)
4033                         goto failed_mount3a;
4034         } else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4035                    ext4_has_feature_journal_needs_recovery(sb)) {
4036                 ext4_msg(sb, KERN_ERR, "required journal recovery "
4037                        "suppressed and not mounted read-only");
4038                 goto failed_mount_wq;
4039         } else {
4040                 /* Nojournal mode, all journal mount options are illegal */
4041                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4042                         ext4_msg(sb, KERN_ERR, "can't mount with "
4043                                  "journal_checksum, fs mounted w/o journal");
4044                         goto failed_mount_wq;
4045                 }
4046                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4047                         ext4_msg(sb, KERN_ERR, "can't mount with "
4048                                  "journal_async_commit, fs mounted w/o journal");
4049                         goto failed_mount_wq;
4050                 }
4051                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4052                         ext4_msg(sb, KERN_ERR, "can't mount with "
4053                                  "commit=%lu, fs mounted w/o journal",
4054                                  sbi->s_commit_interval / HZ);
4055                         goto failed_mount_wq;
4056                 }
4057                 if (EXT4_MOUNT_DATA_FLAGS &
4058                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4059                         ext4_msg(sb, KERN_ERR, "can't mount with "
4060                                  "data=, fs mounted w/o journal");
4061                         goto failed_mount_wq;
4062                 }
4063                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4064                 clear_opt(sb, JOURNAL_CHECKSUM);
4065                 clear_opt(sb, DATA_FLAGS);
4066                 sbi->s_journal = NULL;
4067                 needs_recovery = 0;
4068                 goto no_journal;
4069         }
4070 
4071         if (ext4_has_feature_64bit(sb) &&
4072             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4073                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
4074                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4075                 goto failed_mount_wq;
4076         }
4077 
4078         if (!set_journal_csum_feature_set(sb)) {
4079                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4080                          "feature set");
4081                 goto failed_mount_wq;
4082         }
4083 
4084         /* We have now updated the journal if required, so we can
4085          * validate the data journaling mode. */
4086         switch (test_opt(sb, DATA_FLAGS)) {
4087         case 0:
4088                 /* No mode set, assume a default based on the journal
4089                  * capabilities: ORDERED_DATA if the journal can
4090                  * cope, else JOURNAL_DATA
4091                  */
4092                 if (jbd2_journal_check_available_features
4093                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4094                         set_opt(sb, ORDERED_DATA);
4095                 else
4096                         set_opt(sb, JOURNAL_DATA);
4097                 break;
4098 
4099         case EXT4_MOUNT_ORDERED_DATA:
4100         case EXT4_MOUNT_WRITEBACK_DATA:
4101                 if (!jbd2_journal_check_available_features
4102                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4103                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4104                                "requested data journaling mode");
4105                         goto failed_mount_wq;
4106                 }
4107         default:
4108                 break;
4109         }
4110 
4111         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4112             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4113                 ext4_msg(sb, KERN_ERR, "can't mount with "
4114                         "journal_async_commit in data=ordered mode");
4115                 goto failed_mount_wq;
4116         }
4117 
4118         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4119 
4120         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4121 
4122 no_journal:
4123         if (!test_opt(sb, NO_MBCACHE)) {
4124                 sbi->s_ea_block_cache = ext4_xattr_create_cache();
4125                 if (!sbi->s_ea_block_cache) {
4126                         ext4_msg(sb, KERN_ERR,
4127                                  "Failed to create ea_block_cache");
4128                         goto failed_mount_wq;
4129                 }
4130 
4131                 if (ext4_has_feature_ea_inode(sb)) {
4132                         sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4133                         if (!sbi->s_ea_inode_cache) {
4134                                 ext4_msg(sb, KERN_ERR,
4135                                          "Failed to create ea_inode_cache");
4136                                 goto failed_mount_wq;
4137                         }
4138                 }
4139         }
4140 
4141         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4142             (blocksize != PAGE_SIZE)) {
4143                 ext4_msg(sb, KERN_ERR,
4144                          "Unsupported blocksize for fs encryption");
4145                 goto failed_mount_wq;
4146         }
4147 
4148         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4149             !ext4_has_feature_encrypt(sb)) {
4150                 ext4_set_feature_encrypt(sb);
4151                 ext4_commit_super(sb, 1);
4152         }
4153 
4154         /*
4155          * Get the # of file system overhead blocks from the
4156          * superblock if present.
4157          */
4158         if (es->s_overhead_clusters)
4159                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4160         else {
4161                 err = ext4_calculate_overhead(sb);
4162                 if (err)
4163                         goto failed_mount_wq;
4164         }
4165 
4166         /*
4167          * The maximum number of concurrent works can be high and
4168          * concurrency isn't really necessary.  Limit it to 1.
4169          */
4170         EXT4_SB(sb)->rsv_conversion_wq =
4171                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4172         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4173                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4174                 ret = -ENOMEM;
4175                 goto failed_mount4;
4176         }
4177 
4178         /*
4179          * The jbd2_journal_load will have done any necessary log recovery,
4180          * so we can safely mount the rest of the filesystem now.
4181          */
4182 
4183         root = ext4_iget(sb, EXT4_ROOT_INO);
4184         if (IS_ERR(root)) {
4185                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4186                 ret = PTR_ERR(root);
4187                 root = NULL;
4188                 goto failed_mount4;
4189         }
4190         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4191                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4192                 iput(root);
4193                 goto failed_mount4;
4194         }
4195         sb->s_root = d_make_root(root);
4196         if (!sb->s_root) {
4197                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4198                 ret = -ENOMEM;
4199                 goto failed_mount4;
4200         }
4201 
4202         if (ext4_setup_super(sb, es, sb_rdonly(sb)))
4203                 sb->s_flags |= SB_RDONLY;
4204 
4205         /* determine the minimum size of new large inodes, if present */
4206         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4207             sbi->s_want_extra_isize == 0) {
4208                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4209                                                      EXT4_GOOD_OLD_INODE_SIZE;
4210                 if (ext4_has_feature_extra_isize(sb)) {
4211                         if (sbi->s_want_extra_isize <
4212                             le16_to_cpu(es->s_want_extra_isize))
4213                                 sbi->s_want_extra_isize =
4214                                         le16_to_cpu(es->s_want_extra_isize);
4215                         if (sbi->s_want_extra_isize <
4216                             le16_to_cpu(es->s_min_extra_isize))
4217                                 sbi->s_want_extra_isize =
4218                                         le16_to_cpu(es->s_min_extra_isize);
4219                 }
4220         }
4221         /* Check if enough inode space is available */
4222         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4223                                                         sbi->s_inode_size) {
4224                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4225                                                        EXT4_GOOD_OLD_INODE_SIZE;
4226                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4227                          "available");
4228         }
4229 
4230         ext4_set_resv_clusters(sb);
4231 
4232         err = ext4_setup_system_zone(sb);
4233         if (err) {
4234                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4235                          "zone (%d)", err);
4236                 goto failed_mount4a;
4237         }
4238 
4239         ext4_ext_init(sb);
4240         err = ext4_mb_init(sb);
4241         if (err) {
4242                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4243                          err);
4244                 goto failed_mount5;
4245         }
4246 
4247         block = ext4_count_free_clusters(sb);
4248         ext4_free_blocks_count_set(sbi->s_es, 
4249                                    EXT4_C2B(sbi, block));
4250         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4251                                   GFP_KERNEL);
4252         if (!err) {
4253                 unsigned long freei = ext4_count_free_inodes(sb);
4254                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4255                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4256                                           GFP_KERNEL);
4257         }
4258         if (!err)
4259                 err = percpu_counter_init(&sbi->s_dirs_counter,
4260                                           ext4_count_dirs(sb), GFP_KERNEL);
4261         if (!err)
4262                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4263                                           GFP_KERNEL);
4264         if (!err)
4265                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4266 
4267         if (err) {
4268                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4269                 goto failed_mount6;
4270         }
4271 
4272         if (ext4_has_feature_flex_bg(sb))
4273                 if (!ext4_fill_flex_info(sb)) {
4274                         ext4_msg(sb, KERN_ERR,
4275                                "unable to initialize "
4276                                "flex_bg meta info!");
4277                         goto failed_mount6;
4278                 }
4279 
4280         err = ext4_register_li_request(sb, first_not_zeroed);
4281         if (err)
4282                 goto failed_mount6;
4283 
4284         err = ext4_register_sysfs(sb);
4285         if (err)
4286                 goto failed_mount7;
4287 
4288 #ifdef CONFIG_QUOTA
4289         /* Enable quota usage during mount. */
4290         if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4291                 err = ext4_enable_quotas(sb);
4292                 if (err)
4293                         goto failed_mount8;
4294         }
4295 #endif  /* CONFIG_QUOTA */
4296 
4297         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4298         ext4_orphan_cleanup(sb, es);
4299         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4300         if (needs_recovery) {
4301                 ext4_msg(sb, KERN_INFO, "recovery complete");
4302                 ext4_mark_recovery_complete(sb, es);
4303         }
4304         if (EXT4_SB(sb)->s_journal) {
4305                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4306                         descr = " journalled data mode";
4307                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4308                         descr = " ordered data mode";
4309                 else
4310                         descr = " writeback data mode";
4311         } else
4312                 descr = "out journal";
4313 
4314         if (test_opt(sb, DISCARD)) {
4315                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4316                 if (!blk_queue_discard(q))
4317                         ext4_msg(sb, KERN_WARNING,
4318                                  "mounting with \"discard\" option, but "
4319                                  "the device does not support discard");
4320         }
4321 
4322         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4323                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4324                          "Opts: %.*s%s%s", descr,
4325                          (int) sizeof(sbi->s_es->s_mount_opts),
4326                          sbi->s_es->s_mount_opts,
4327                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4328 
4329         if (es->s_error_count)
4330                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4331 
4332         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4333         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4334         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4335         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4336 
4337         kfree(orig_data);
4338         return 0;
4339 
4340 cantfind_ext4:
4341         if (!silent)
4342                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4343         goto failed_mount;
4344 
4345 #ifdef CONFIG_QUOTA
4346 failed_mount8:
4347         ext4_unregister_sysfs(sb);
4348 #endif
4349 failed_mount7:
4350         ext4_unregister_li_request(sb);
4351 failed_mount6:
4352         ext4_mb_release(sb);
4353         if (sbi->s_flex_groups)
4354                 kvfree(sbi->s_flex_groups);
4355         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4356         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4357         percpu_counter_destroy(&sbi->s_dirs_counter);
4358         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4359 failed_mount5:
4360         ext4_ext_release(sb);
4361         ext4_release_system_zone(sb);
4362 failed_mount4a:
4363         dput(sb->s_root);
4364         sb->s_root = NULL;
4365 failed_mount4:
4366         ext4_msg(sb, KERN_ERR, "mount failed");
4367         if (EXT4_SB(sb)->rsv_conversion_wq)
4368                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4369 failed_mount_wq:
4370         if (sbi->s_ea_inode_cache) {
4371                 ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4372                 sbi->s_ea_inode_cache = NULL;
4373         }
4374         if (sbi->s_ea_block_cache) {
4375                 ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4376                 sbi->s_ea_block_cache = NULL;
4377         }
4378         if (sbi->s_journal) {
4379                 jbd2_journal_destroy(sbi->s_journal);
4380                 sbi->s_journal = NULL;
4381         }
4382 failed_mount3a:
4383         ext4_es_unregister_shrinker(sbi);
4384 failed_mount3:
4385         del_timer_sync(&sbi->s_err_report);
4386         if (sbi->s_mmp_tsk)
4387                 kthread_stop(sbi->s_mmp_tsk);
4388 failed_mount2:
4389         for (i = 0; i < db_count; i++)
4390                 brelse(sbi->s_group_desc[i]);
4391         kvfree(sbi->s_group_desc);
4392 failed_mount:
4393         if (sbi->s_chksum_driver)
4394                 crypto_free_shash(sbi->s_chksum_driver);
4395 #ifdef CONFIG_QUOTA
4396         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4397                 kfree(sbi->s_qf_names[i]);
4398 #endif
4399         ext4_blkdev_remove(sbi);
4400         brelse(bh);
4401 out_fail:
4402         sb->s_fs_info = NULL;
4403         kfree(sbi->s_blockgroup_lock);
4404 out_free_base:
4405         kfree(sbi);
4406         kfree(orig_data);
4407         fs_put_dax(dax_dev);
4408         return err ? err : ret;
4409 }
4410 
4411 /*
4412  * Setup any per-fs journal parameters now.  We'll do this both on
4413  * initial mount, once the journal has been initialised but before we've
4414  * done any recovery; and again on any subsequent remount.
4415  */
4416 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4417 {
4418         struct ext4_sb_info *sbi = EXT4_SB(sb);
4419 
4420         journal->j_commit_interval = sbi->s_commit_interval;
4421         journal->j_min_batch_time = sbi->s_min_batch_time;
4422         journal->j_max_batch_time = sbi->s_max_batch_time;
4423 
4424         write_lock(&journal->j_state_lock);
4425         if (test_opt(sb, BARRIER))
4426                 journal->j_flags |= JBD2_BARRIER;
4427         else
4428                 journal->j_flags &= ~JBD2_BARRIER;
4429         if (test_opt(sb, DATA_ERR_ABORT))
4430                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4431         else
4432                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4433         write_unlock(&journal->j_state_lock);
4434 }
4435 
4436 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4437                                              unsigned int journal_inum)
4438 {
4439         struct inode *journal_inode;
4440 
4441         /*
4442          * Test for the existence of a valid inode on disk.  Bad things
4443          * happen if we iget() an unused inode, as the subsequent iput()
4444          * will try to delete it.
4445          */
4446         journal_inode = ext4_iget(sb, journal_inum);
4447         if (IS_ERR(journal_inode)) {
4448                 ext4_msg(sb, KERN_ERR, "no journal found");
4449                 return NULL;
4450         }
4451         if (!journal_inode->i_nlink) {
4452                 make_bad_inode(journal_inode);
4453                 iput(journal_inode);
4454                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4455                 return NULL;
4456         }
4457 
4458         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4459                   journal_inode, journal_inode->i_size);
4460         if (!S_ISREG(journal_inode->i_mode)) {
4461                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4462                 iput(journal_inode);
4463                 return NULL;
4464         }
4465         return journal_inode;
4466 }
4467 
4468 static journal_t *ext4_get_journal(struct super_block *sb,
4469                                    unsigned int journal_inum)
4470 {
4471         struct inode *journal_inode;
4472         journal_t *journal;
4473 
4474         BUG_ON(!ext4_has_feature_journal(sb));
4475 
4476         journal_inode = ext4_get_journal_inode(sb, journal_inum);
4477         if (!journal_inode)
4478                 return NULL;
4479 
4480         journal = jbd2_journal_init_inode(journal_inode);
4481         if (!journal) {
4482                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4483                 iput(journal_inode);
4484                 return NULL;
4485         }
4486         journal->j_private = sb;
4487         ext4_init_journal_params(sb, journal);
4488         return journal;
4489 }
4490 
4491 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4492                                        dev_t j_dev)
4493 {
4494         struct buffer_head *bh;
4495         journal_t *journal;
4496         ext4_fsblk_t start;
4497         ext4_fsblk_t len;
4498         int hblock, blocksize;
4499         ext4_fsblk_t sb_block;
4500         unsigned long offset;
4501         struct ext4_super_block *es;
4502         struct block_device *bdev;
4503 
4504         BUG_ON(!ext4_has_feature_journal(sb));
4505 
4506         bdev = ext4_blkdev_get(j_dev, sb);
4507         if (bdev == NULL)
4508                 return NULL;
4509 
4510         blocksize = sb->s_blocksize;
4511         hblock = bdev_logical_block_size(bdev);
4512         if (blocksize < hblock) {
4513                 ext4_msg(sb, KERN_ERR,
4514                         "blocksize too small for journal device");
4515                 goto out_bdev;
4516         }
4517 
4518         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4519         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4520         set_blocksize(bdev, blocksize);
4521         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4522                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4523                        "external journal");
4524                 goto out_bdev;
4525         }
4526 
4527         es = (struct ext4_super_block *) (bh->b_data + offset);
4528         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4529             !(le32_to_cpu(es->s_feature_incompat) &
4530               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4531                 ext4_msg(sb, KERN_ERR, "external journal has "
4532                                         "bad superblock");
4533                 brelse(bh);
4534                 goto out_bdev;
4535         }
4536 
4537         if ((le32_to_cpu(es->s_feature_ro_compat) &
4538              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4539             es->s_checksum != ext4_superblock_csum(sb, es)) {
4540                 ext4_msg(sb, KERN_ERR, "external journal has "
4541                                        "corrupt superblock");
4542                 brelse(bh);
4543                 goto out_bdev;
4544         }
4545 
4546         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4547                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4548                 brelse(bh);
4549                 goto out_bdev;
4550         }
4551 
4552         len = ext4_blocks_count(es);
4553         start = sb_block + 1;
4554         brelse(bh);     /* we're done with the superblock */
4555 
4556         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4557                                         start, len, blocksize);
4558         if (!journal) {
4559                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4560                 goto out_bdev;
4561         }
4562         journal->j_private = sb;
4563         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4564         wait_on_buffer(journal->j_sb_buffer);
4565         if (!buffer_uptodate(journal->j_sb_buffer)) {
4566                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4567                 goto out_journal;
4568         }
4569         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4570                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4571                                         "user (unsupported) - %d",
4572                         be32_to_cpu(journal->j_superblock->s_nr_users));
4573                 goto out_journal;
4574         }
4575         EXT4_SB(sb)->journal_bdev = bdev;
4576         ext4_init_journal_params(sb, journal);
4577         return journal;
4578 
4579 out_journal:
4580         jbd2_journal_destroy(journal);
4581 out_bdev:
4582         ext4_blkdev_put(bdev);
4583         return NULL;
4584 }
4585 
4586 static int ext4_load_journal(struct super_block *sb,
4587                              struct ext4_super_block *es,
4588                              unsigned long journal_devnum)
4589 {
4590         journal_t *journal;
4591         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4592         dev_t journal_dev;
4593         int err = 0;
4594         int really_read_only;
4595 
4596         BUG_ON(!ext4_has_feature_journal(sb));
4597 
4598         if (journal_devnum &&
4599             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4600                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4601                         "numbers have changed");
4602                 journal_dev = new_decode_dev(journal_devnum);
4603         } else
4604                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4605 
4606         really_read_only = bdev_read_only(sb->s_bdev);
4607 
4608         /*
4609          * Are we loading a blank journal or performing recovery after a
4610          * crash?  For recovery, we need to check in advance whether we
4611          * can get read-write access to the device.
4612          */
4613         if (ext4_has_feature_journal_needs_recovery(sb)) {
4614                 if (sb_rdonly(sb)) {
4615                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4616                                         "required on readonly filesystem");
4617                         if (really_read_only) {
4618                                 ext4_msg(sb, KERN_ERR, "write access "
4619                                         "unavailable, cannot proceed "
4620                                         "(try mounting with noload)");
4621                                 return -EROFS;
4622                         }
4623                         ext4_msg(sb, KERN_INFO, "write access will "
4624                                "be enabled during recovery");
4625                 }
4626         }
4627 
4628         if (journal_inum && journal_dev) {
4629                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4630                        "and inode journals!");
4631                 return -EINVAL;
4632         }
4633 
4634         if (journal_inum) {
4635                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4636                         return -EINVAL;
4637         } else {
4638                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4639                         return -EINVAL;
4640         }
4641 
4642         if (!(journal->j_flags & JBD2_BARRIER))
4643                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4644 
4645         if (!ext4_has_feature_journal_needs_recovery(sb))
4646                 err = jbd2_journal_wipe(journal, !really_read_only);
4647         if (!err) {
4648                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4649                 if (save)
4650                         memcpy(save, ((char *) es) +
4651                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4652                 err = jbd2_journal_load(journal);
4653                 if (save)
4654                         memcpy(((char *) es) + EXT4_S_ERR_START,
4655                                save, EXT4_S_ERR_LEN);
4656                 kfree(save);
4657         }
4658 
4659         if (err) {
4660                 ext4_msg(sb, KERN_ERR, "error loading journal");
4661                 jbd2_journal_destroy(journal);
4662                 return err;
4663         }
4664 
4665         EXT4_SB(sb)->s_journal = journal;
4666         ext4_clear_journal_err(sb, es);
4667 
4668         if (!really_read_only && journal_devnum &&
4669             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4670                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4671 
4672                 /* Make sure we flush the recovery flag to disk. */
4673                 ext4_commit_super(sb, 1);
4674         }
4675 
4676         return 0;
4677 }
4678 
4679 static int ext4_commit_super(struct super_block *sb, int sync)
4680 {
4681         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4682         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4683         int error = 0;
4684 
4685         if (!sbh || block_device_ejected(sb))
4686                 return error;
4687         /*
4688          * If the file system is mounted read-only, don't update the
4689          * superblock write time.  This avoids updating the superblock
4690          * write time when we are mounting the root file system
4691          * read/only but we need to replay the journal; at that point,
4692          * for people who are east of GMT and who make their clock
4693          * tick in localtime for Windows bug-for-bug compatibility,
4694          * the clock is set in the future, and this will cause e2fsck
4695          * to complain and force a full file system check.
4696          */
4697         if (!(sb->s_flags & SB_RDONLY))
4698                 es->s_wtime = cpu_to_le32(get_seconds());
4699         if (sb->s_bdev->bd_part)
4700                 es->s_kbytes_written =
4701                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4702                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4703                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4704         else
4705                 es->s_kbytes_written =
4706                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4707         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4708                 ext4_free_blocks_count_set(es,
4709                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4710                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4711         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4712                 es->s_free_inodes_count =
4713                         cpu_to_le32(percpu_counter_sum_positive(
4714                                 &EXT4_SB(sb)->s_freeinodes_counter));
4715         BUFFER_TRACE(sbh, "marking dirty");
4716         ext4_superblock_csum_set(sb);
4717         if (sync)
4718                 lock_buffer(sbh);
4719         if (buffer_write_io_error(sbh)) {
4720                 /*
4721                  * Oh, dear.  A previous attempt to write the
4722                  * superblock failed.  This could happen because the
4723                  * USB device was yanked out.  Or it could happen to
4724                  * be a transient write error and maybe the block will
4725                  * be remapped.  Nothing we can do but to retry the
4726                  * write and hope for the best.
4727                  */
4728                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4729                        "superblock detected");
4730                 clear_buffer_write_io_error(sbh);
4731                 set_buffer_uptodate(sbh);
4732         }
4733         mark_buffer_dirty(sbh);
4734         if (sync) {
4735                 unlock_buffer(sbh);
4736                 error = __sync_dirty_buffer(sbh,
4737                         REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4738                 if (error)
4739                         return error;
4740 
4741                 error = buffer_write_io_error(sbh);
4742                 if (error) {
4743                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4744                                "superblock");
4745                         clear_buffer_write_io_error(sbh);
4746                         set_buffer_uptodate(sbh);
4747                 }
4748         }
4749         return error;
4750 }
4751 
4752 /*
4753  * Have we just finished recovery?  If so, and if we are mounting (or
4754  * remounting) the filesystem readonly, then we will end up with a
4755  * consistent fs on disk.  Record that fact.
4756  */
4757 static void ext4_mark_recovery_complete(struct super_block *sb,
4758                                         struct ext4_super_block *es)
4759 {
4760         journal_t *journal = EXT4_SB(sb)->s_journal;
4761 
4762         if (!ext4_has_feature_journal(sb)) {
4763                 BUG_ON(journal != NULL);
4764                 return;
4765         }
4766         jbd2_journal_lock_updates(journal);
4767         if (jbd2_journal_flush(journal) < 0)
4768                 goto out;
4769 
4770         if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
4771                 ext4_clear_feature_journal_needs_recovery(sb);
4772                 ext4_commit_super(sb, 1);
4773         }
4774 
4775 out:
4776         jbd2_journal_unlock_updates(journal);
4777 }
4778 
4779 /*
4780  * If we are mounting (or read-write remounting) a filesystem whose journal
4781  * has recorded an error from a previous lifetime, move that error to the
4782  * main filesystem now.
4783  */
4784 static void ext4_clear_journal_err(struct super_block *sb,
4785                                    struct ext4_super_block *es)
4786 {
4787         journal_t *journal;
4788         int j_errno;
4789         const char *errstr;
4790 
4791         BUG_ON(!ext4_has_feature_journal(sb));
4792 
4793         journal = EXT4_SB(sb)->s_journal;
4794 
4795         /*
4796          * Now check for any error status which may have been recorded in the
4797          * journal by a prior ext4_error() or ext4_abort()
4798          */
4799 
4800         j_errno = jbd2_journal_errno(journal);
4801         if (j_errno) {
4802                 char nbuf[16];
4803 
4804                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4805                 ext4_warning(sb, "Filesystem error recorded "
4806                              "from previous mount: %s", errstr);
4807                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4808 
4809                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4810                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4811                 ext4_commit_super(sb, 1);
4812 
4813                 jbd2_journal_clear_err(journal);
4814                 jbd2_journal_update_sb_errno(journal);
4815         }
4816 }
4817 
4818 /*
4819  * Force the running and committing transactions to commit,
4820  * and wait on the commit.
4821  */
4822 int ext4_force_commit(struct super_block *sb)
4823 {
4824         journal_t *journal;
4825 
4826         if (sb_rdonly(sb))
4827                 return 0;
4828 
4829         journal = EXT4_SB(sb)->s_journal;
4830         return ext4_journal_force_commit(journal);
4831 }
4832 
4833 static int ext4_sync_fs(struct super_block *sb, int wait)
4834 {
4835         int ret = 0;
4836         tid_t target;
4837         bool needs_barrier = false;
4838         struct ext4_sb_info *sbi = EXT4_SB(sb);
4839 
4840         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4841                 return 0;
4842 
4843         trace_ext4_sync_fs(sb, wait);
4844         flush_workqueue(sbi->rsv_conversion_wq);
4845         /*
4846          * Writeback quota in non-journalled quota case - journalled quota has
4847          * no dirty dquots
4848          */
4849         dquot_writeback_dquots(sb, -1);
4850         /*
4851          * Data writeback is possible w/o journal transaction, so barrier must
4852          * being sent at the end of the function. But we can skip it if
4853          * transaction_commit will do it for us.
4854          */
4855         if (sbi->s_journal) {
4856                 target = jbd2_get_latest_transaction(sbi->s_journal);
4857                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4858                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4859                         needs_barrier = true;
4860 
4861                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4862                         if (wait)
4863                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4864                                                            target);
4865                 }
4866         } else if (wait && test_opt(sb, BARRIER))
4867                 needs_barrier = true;
4868         if (needs_barrier) {
4869                 int err;
4870                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4871                 if (!ret)
4872                         ret = err;
4873         }
4874 
4875         return ret;
4876 }
4877 
4878 /*
4879  * LVM calls this function before a (read-only) snapshot is created.  This
4880  * gives us a chance to flush the journal completely and mark the fs clean.
4881  *
4882  * Note that only this function cannot bring a filesystem to be in a clean
4883  * state independently. It relies on upper layer to stop all data & metadata
4884  * modifications.
4885  */
4886 static int ext4_freeze(struct super_block *sb)
4887 {
4888         int error = 0;
4889         journal_t *journal;
4890 
4891         if (sb_rdonly(sb))
4892                 return 0;
4893 
4894         journal = EXT4_SB(sb)->s_journal;
4895 
4896         if (journal) {
4897                 /* Now we set up the journal barrier. */
4898                 jbd2_journal_lock_updates(journal);
4899 
4900                 /*
4901                  * Don't clear the needs_recovery flag if we failed to
4902                  * flush the journal.
4903                  */
4904                 error = jbd2_journal_flush(journal);
4905                 if (error < 0)
4906                         goto out;
4907 
4908                 /* Journal blocked and flushed, clear needs_recovery flag. */
4909                 ext4_clear_feature_journal_needs_recovery(sb);
4910         }
4911 
4912         error = ext4_commit_super(sb, 1);
4913 out:
4914         if (journal)
4915                 /* we rely on upper layer to stop further updates */
4916                 jbd2_journal_unlock_updates(journal);
4917         return error;
4918 }
4919 
4920 /*
4921  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4922  * flag here, even though the filesystem is not technically dirty yet.
4923  */
4924 static int ext4_unfreeze(struct super_block *sb)
4925 {
4926         if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
4927                 return 0;
4928 
4929         if (EXT4_SB(sb)->s_journal) {
4930                 /* Reset the needs_recovery flag before the fs is unlocked. */
4931                 ext4_set_feature_journal_needs_recovery(sb);
4932         }
4933 
4934         ext4_commit_super(sb, 1);
4935         return 0;
4936 }
4937 
4938 /*
4939  * Structure to save mount options for ext4_remount's benefit
4940  */
4941 struct ext4_mount_options {
4942         unsigned long s_mount_opt;
4943         unsigned long s_mount_opt2;
4944         kuid_t s_resuid;
4945         kgid_t s_resgid;
4946         unsigned long s_commit_interval;
4947         u32 s_min_batch_time, s_max_batch_time;
4948 #ifdef CONFIG_QUOTA
4949         int s_jquota_fmt;
4950         char *s_qf_names[EXT4_MAXQUOTAS];
4951 #endif
4952 };
4953 
4954 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4955 {
4956         struct ext4_super_block *es;
4957         struct ext4_sb_info *sbi = EXT4_SB(sb);
4958         unsigned long old_sb_flags;
4959         struct ext4_mount_options old_opts;
4960         int enable_quota = 0;
4961         ext4_group_t g;
4962         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4963         int err = 0;
4964 #ifdef CONFIG_QUOTA
4965         int i, j;
4966 #endif
4967         char *orig_data = kstrdup(data, GFP_KERNEL);
4968 
4969         /* Store the original options */
4970         old_sb_flags = sb->s_flags;
4971         old_opts.s_mount_opt = sbi->s_mount_opt;
4972         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4973         old_opts.s_resuid = sbi->s_resuid;
4974         old_opts.s_resgid = sbi->s_resgid;
4975         old_opts.s_commit_interval = sbi->s_commit_interval;
4976         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4977         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4978 #ifdef CONFIG_QUOTA
4979         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4980         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4981                 if (sbi->s_qf_names[i]) {
4982                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4983                                                          GFP_KERNEL);
4984                         if (!old_opts.s_qf_names[i]) {
4985                                 for (j = 0; j < i; j++)
4986                                         kfree(old_opts.s_qf_names[j]);
4987                                 kfree(orig_data);
4988                                 return -ENOMEM;
4989                         }
4990                 } else
4991                         old_opts.s_qf_names[i] = NULL;
4992 #endif
4993         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4994                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4995 
4996         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4997                 err = -EINVAL;
4998                 goto restore_opts;
4999         }
5000 
5001         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5002             test_opt(sb, JOURNAL_CHECKSUM)) {
5003                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5004                          "during remount not supported; ignoring");
5005                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5006         }
5007 
5008         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5009                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5010                         ext4_msg(sb, KERN_ERR, "can't mount with "
5011                                  "both data=journal and delalloc");
5012                         err = -EINVAL;
5013                         goto restore_opts;
5014                 }
5015                 if (test_opt(sb, DIOREAD_NOLOCK)) {
5016                         ext4_msg(sb, KERN_ERR, "can't mount with "
5017                                  "both data=journal and dioread_nolock");
5018                         err = -EINVAL;
5019                         goto restore_opts;
5020                 }
5021                 if (test_opt(sb, DAX)) {
5022                         ext4_msg(sb, KERN_ERR, "can't mount with "
5023                                  "both data=journal and dax");
5024                         err = -EINVAL;
5025                         goto restore_opts;
5026                 }
5027         } else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5028                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5029                         ext4_msg(sb, KERN_ERR, "can't mount with "
5030                                 "journal_async_commit in data=ordered mode");
5031                         err = -EINVAL;
5032                         goto restore_opts;
5033                 }
5034         }
5035 
5036         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5037                 ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5038                 err = -EINVAL;
5039                 goto restore_opts;
5040         }
5041 
5042         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5043                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5044                         "dax flag with busy inodes while remounting");
5045                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5046         }
5047 
5048         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5049                 ext4_abort(sb, "Abort forced by user");
5050 
5051         sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5052                 (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5053 
5054         es = sbi->s_es;
5055 
5056         if (sbi->s_journal) {
5057                 ext4_init_journal_params(sb, sbi->s_journal);
5058                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5059         }
5060 
5061         if (*flags & SB_LAZYTIME)
5062                 sb->s_flags |= SB_LAZYTIME;
5063 
5064         if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5065                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5066                         err = -EROFS;
5067                         goto restore_opts;
5068                 }
5069 
5070                 if (*flags & SB_RDONLY) {
5071                         err = sync_filesystem(sb);
5072                         if (err < 0)
5073                                 goto restore_opts;
5074                         err = dquot_suspend(sb, -1);
5075                         if (err < 0)
5076                                 goto restore_opts;
5077 
5078                         /*
5079                          * First of all, the unconditional stuff we have to do
5080                          * to disable replay of the journal when we next remount
5081                          */
5082                         sb->s_flags |= SB_RDONLY;
5083 
5084                         /*
5085                          * OK, test if we are remounting a valid rw partition
5086                          * readonly, and if so set the rdonly flag and then
5087                          * mark the partition as valid again.
5088                          */
5089                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5090                             (sbi->s_mount_state & EXT4_VALID_FS))
5091                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
5092 
5093                         if (sbi->s_journal)
5094                                 ext4_mark_recovery_complete(sb, es);
5095                 } else {
5096                         /* Make sure we can mount this feature set readwrite */
5097                         if (ext4_has_feature_readonly(sb) ||
5098                             !ext4_feature_set_ok(sb, 0)) {
5099                                 err = -EROFS;
5100                                 goto restore_opts;
5101                         }
5102                         /*
5103                          * Make sure the group descriptor checksums
5104                          * are sane.  If they aren't, refuse to remount r/w.
5105                          */
5106                         for (g = 0; g < sbi->s_groups_count; g++) {
5107                                 struct ext4_group_desc *gdp =
5108                                         ext4_get_group_desc(sb, g, NULL);
5109 
5110                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5111                                         ext4_msg(sb, KERN_ERR,
5112                "ext4_remount: Checksum for group %u failed (%u!=%u)",
5113                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5114                                                le16_to_cpu(gdp->bg_checksum));
5115                                         err = -EFSBADCRC;
5116                                         goto restore_opts;
5117                                 }
5118                         }
5119 
5120                         /*
5121                          * If we have an unprocessed orphan list hanging
5122                          * around from a previously readonly bdev mount,
5123                          * require a full umount/remount for now.
5124                          */
5125                         if (es->s_last_orphan) {
5126                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
5127                                        "remount RDWR because of unprocessed "
5128                                        "orphan inode list.  Please "
5129                                        "umount/remount instead");
5130                                 err = -EINVAL;
5131                                 goto restore_opts;
5132                         }
5133 
5134                         /*
5135                          * Mounting a RDONLY partition read-write, so reread
5136                          * and store the current valid flag.  (It may have
5137                          * been changed by e2fsck since we originally mounted
5138                          * the partition.)
5139                          */
5140                         if (sbi->s_journal)
5141                                 ext4_clear_journal_err(sb, es);
5142                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5143                         if (!ext4_setup_super(sb, es, 0))
5144                                 sb->s_flags &= ~SB_RDONLY;
5145                         if (ext4_has_feature_mmp(sb))
5146                                 if (ext4_multi_mount_protect(sb,
5147                                                 le64_to_cpu(es->s_mmp_block))) {
5148                                         err = -EROFS;
5149                                         goto restore_opts;
5150                                 }
5151                         enable_quota = 1;
5152                 }
5153         }
5154 
5155         /*
5156          * Reinitialize lazy itable initialization thread based on
5157          * current settings
5158          */
5159         if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5160                 ext4_unregister_li_request(sb);
5161         else {
5162                 ext4_group_t first_not_zeroed;
5163                 first_not_zeroed = ext4_has_uninit_itable(sb);
5164                 ext4_register_li_request(sb, first_not_zeroed);
5165         }
5166 
5167         ext4_setup_system_zone(sb);
5168         if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY))
5169                 ext4_commit_super(sb, 1);
5170 
5171 #ifdef CONFIG_QUOTA
5172         /* Release old quota file names */
5173         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5174                 kfree(old_opts.s_qf_names[i]);
5175         if (enable_quota) {
5176                 if (sb_any_quota_suspended(sb))
5177                         dquot_resume(sb, -1);
5178                 else if (ext4_has_feature_quota(sb)) {
5179                         err = ext4_enable_quotas(sb);
5180                         if (err)
5181                                 goto restore_opts;
5182                 }
5183         }
5184 #endif
5185 
5186         *flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5187         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5188         kfree(orig_data);
5189         return 0;
5190 
5191 restore_opts:
5192         sb->s_flags = old_sb_flags;
5193         sbi->s_mount_opt = old_opts.s_mount_opt;
5194         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5195         sbi->s_resuid = old_opts.s_resuid;
5196         sbi->s_resgid = old_opts.s_resgid;
5197         sbi->s_commit_interval = old_opts.s_commit_interval;
5198         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5199         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5200 #ifdef CONFIG_QUOTA
5201         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5202         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5203                 kfree(sbi->s_qf_names[i]);
5204                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5205         }
5206 #endif
5207         kfree(orig_data);
5208         return err;
5209 }
5210 
5211 #ifdef CONFIG_QUOTA
5212 static int ext4_statfs_project(struct super_block *sb,
5213                                kprojid_t projid, struct kstatfs *buf)
5214 {
5215         struct kqid qid;
5216         struct dquot *dquot;
5217         u64 limit;
5218         u64 curblock;
5219 
5220         qid = make_kqid_projid(projid);
5221         dquot = dqget(sb, qid);
5222         if (IS_ERR(dquot))
5223                 return PTR_ERR(dquot);
5224         spin_lock(&dquot->dq_dqb_lock);
5225 
5226         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5227                  dquot->dq_dqb.dqb_bsoftlimit :
5228                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5229         if (limit && buf->f_blocks > limit) {
5230                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5231                 buf->f_blocks = limit;
5232                 buf->f_bfree = buf->f_bavail =
5233                         (buf->f_blocks > curblock) ?
5234                          (buf->f_blocks - curblock) : 0;
5235         }
5236 
5237         limit = dquot->dq_dqb.dqb_isoftlimit ?
5238                 dquot->dq_dqb.dqb_isoftlimit :
5239                 dquot->dq_dqb.dqb_ihardlimit;
5240         if (limit && buf->f_files > limit) {
5241                 buf->f_files = limit;
5242                 buf->f_ffree =
5243                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5244                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5245         }
5246 
5247         spin_unlock(&dquot->dq_dqb_lock);
5248         dqput(dquot);
5249         return 0;
5250 }
5251 #endif
5252 
5253 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5254 {
5255         struct super_block *sb = dentry->d_sb;
5256         struct ext4_sb_info *sbi = EXT4_SB(sb);
5257         struct ext4_super_block *es = sbi->s_es;
5258         ext4_fsblk_t overhead = 0, resv_blocks;
5259         u64 fsid;
5260         s64 bfree;
5261         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5262 
5263         if (!test_opt(sb, MINIX_DF))
5264                 overhead = sbi->s_overhead;
5265 
5266         buf->f_type = EXT4_SUPER_MAGIC;
5267         buf->f_bsize = sb->s_blocksize;
5268         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5269         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5270                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5271         /* prevent underflow in case that few free space is available */
5272         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5273         buf->f_bavail = buf->f_bfree -
5274                         (ext4_r_blocks_count(es) + resv_blocks);
5275         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5276                 buf->f_bavail = 0;
5277         buf->f_files = le32_to_cpu(es->s_inodes_count);
5278         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5279         buf->f_namelen = EXT4_NAME_LEN;
5280         fsid = le64_to_cpup((void *)es->s_uuid) ^
5281                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5282         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5283         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5284 
5285 #ifdef CONFIG_QUOTA
5286         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5287             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5288                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5289 #endif
5290         return 0;
5291 }
5292 
5293 
5294 #ifdef CONFIG_QUOTA
5295 
5296 /*
5297  * Helper functions so that transaction is started before we acquire dqio_sem
5298  * to keep correct lock ordering of transaction > dqio_sem
5299  */
5300 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5301 {
5302         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5303 }
5304 
5305 static int ext4_write_dquot(struct dquot *dquot)
5306 {
5307         int ret, err;
5308         handle_t *handle;
5309         struct inode *inode;
5310 
5311         inode = dquot_to_inode(dquot);
5312         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5313                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5314         if (IS_ERR(handle))
5315                 return PTR_ERR(handle);
5316         ret = dquot_commit(dquot);
5317         err = ext4_journal_stop(handle);
5318         if (!ret)
5319                 ret = err;
5320         return ret;
5321 }
5322 
5323 static int ext4_acquire_dquot(struct dquot *dquot)
5324 {
5325         int ret, err;
5326         handle_t *handle;
5327 
5328         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5329                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5330         if (IS_ERR(handle))
5331                 return PTR_ERR(handle);
5332         ret = dquot_acquire(dquot);
5333         err = ext4_journal_stop(handle);
5334         if (!ret)
5335                 ret = err;
5336         return ret;
5337 }
5338 
5339 static int ext4_release_dquot(struct dquot *dquot)
5340 {
5341         int ret, err;
5342         handle_t *handle;
5343 
5344         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5345                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5346         if (IS_ERR(handle)) {
5347                 /* Release dquot anyway to avoid endless cycle in dqput() */
5348                 dquot_release(dquot);
5349                 return PTR_ERR(handle);
5350         }
5351         ret = dquot_release(dquot);
5352         err = ext4_journal_stop(handle);
5353         if (!ret)
5354                 ret = err;
5355         return ret;
5356 }
5357 
5358 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5359 {
5360         struct super_block *sb = dquot->dq_sb;
5361         struct ext4_sb_info *sbi = EXT4_SB(sb);
5362 
5363         /* Are we journaling quotas? */
5364         if (ext4_has_feature_quota(sb) ||
5365             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5366                 dquot_mark_dquot_dirty(dquot);
5367                 return ext4_write_dquot(dquot);
5368         } else {
5369                 return dquot_mark_dquot_dirty(dquot);
5370         }
5371 }
5372 
5373 static int ext4_write_info(struct super_block *sb, int type)
5374 {
5375         int ret, err;
5376         handle_t *handle;
5377 
5378         /* Data block + inode block */
5379         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5380         if (IS_ERR(handle))
5381                 return PTR_ERR(handle);
5382         ret = dquot_commit_info(sb, type);
5383         err = ext4_journal_stop(handle);
5384         if (!ret)
5385                 ret = err;
5386         return ret;
5387 }
5388 
5389 /*
5390  * Turn on quotas during mount time - we need to find
5391  * the quota file and such...
5392  */
5393 static int ext4_quota_on_mount(struct super_block *sb, int type)
5394 {
5395         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5396                                         EXT4_SB(sb)->s_jquota_fmt, type);
5397 }
5398 
5399 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5400 {
5401         struct ext4_inode_info *ei = EXT4_I(inode);
5402 
5403         /* The first argument of lockdep_set_subclass has to be
5404          * *exactly* the same as the argument to init_rwsem() --- in
5405          * this case, in init_once() --- or lockdep gets unhappy
5406          * because the name of the lock is set using the
5407          * stringification of the argument to init_rwsem().
5408          */
5409         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5410         lockdep_set_subclass(&ei->i_data_sem, subclass);
5411 }
5412 
5413 /*
5414  * Standard function to be called on quota_on
5415  */
5416 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5417                          const struct path *path)
5418 {
5419         int err;
5420 
5421         if (!test_opt(sb, QUOTA))
5422                 return -EINVAL;
5423 
5424         /* Quotafile not on the same filesystem? */
5425         if (path->dentry->d_sb != sb)
5426                 return -EXDEV;
5427         /* Journaling quota? */
5428         if (EXT4_SB(sb)->s_qf_names[type]) {
5429                 /* Quotafile not in fs root? */
5430                 if (path->dentry->d_parent != sb->s_root)
5431                         ext4_msg(sb, KERN_WARNING,
5432                                 "Quota file not on filesystem root. "
5433                                 "Journaled quota will not work");
5434                 sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5435         } else {
5436                 /*
5437                  * Clear the flag just in case mount options changed since
5438                  * last time.
5439                  */
5440                 sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5441         }
5442 
5443         /*
5444          * When we journal data on quota file, we have to flush journal to see
5445          * all updates to the file when we bypass pagecache...
5446          */
5447         if (EXT4_SB(sb)->s_journal &&
5448             ext4_should_journal_data(d_inode(path->dentry))) {
5449                 /*
5450                  * We don't need to lock updates but journal_flush() could
5451                  * otherwise be livelocked...
5452                  */
5453                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5454                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5455                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5456                 if (err)
5457                         return err;
5458         }
5459 
5460         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5461         err = dquot_quota_on(sb, type, format_id, path);
5462         if (err) {
5463                 lockdep_set_quota_inode(path->dentry->d_inode,
5464                                              I_DATA_SEM_NORMAL);
5465         } else {
5466                 struct inode *inode = d_inode(path->dentry);
5467                 handle_t *handle;
5468 
5469                 /*
5470                  * Set inode flags to prevent userspace from messing with quota
5471                  * files. If this fails, we return success anyway since quotas
5472                  * are already enabled and this is not a hard failure.
5473                  */
5474                 inode_lock(inode);
5475                 handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5476                 if (IS_ERR(handle))
5477                         goto unlock_inode;
5478                 EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5479                 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5480                                 S_NOATIME | S_IMMUTABLE);
5481                 ext4_mark_inode_dirty(handle, inode);
5482                 ext4_journal_stop(handle);
5483         unlock_inode:
5484                 inode_unlock(inode);
5485         }
5486         return err;
5487 }
5488 
5489 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5490                              unsigned int flags)
5491 {
5492         int err;
5493         struct inode *qf_inode;
5494         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5495                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5496                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5497                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5498         };
5499 
5500         BUG_ON(!ext4_has_feature_quota(sb));
5501 
5502         if (!qf_inums[type])
5503                 return -EPERM;
5504 
5505         qf_inode = ext4_iget(sb, qf_inums[type]);
5506         if (IS_ERR(qf_inode)) {
5507                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5508                 return PTR_ERR(qf_inode);
5509         }
5510 
5511         /* Don't account quota for quota files to avoid recursion */
5512         qf_inode->i_flags |= S_NOQUOTA;
5513         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5514         err = dquot_enable(qf_inode, type, format_id, flags);
5515         iput(qf_inode);
5516         if (err)
5517                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5518 
5519         return err;
5520 }
5521 
5522 /* Enable usage tracking for all quota types. */
5523 static int ext4_enable_quotas(struct super_block *sb)
5524 {
5525         int type, err = 0;
5526         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5527                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5528                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5529                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5530         };
5531         bool quota_mopt[EXT4_MAXQUOTAS] = {
5532                 test_opt(sb, USRQUOTA),
5533                 test_opt(sb, GRPQUOTA),
5534                 test_opt(sb, PRJQUOTA),
5535         };
5536 
5537         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5538         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5539                 if (qf_inums[type]) {
5540                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5541                                 DQUOT_USAGE_ENABLED |
5542                                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5543                         if (err) {
5544                                 for (type--; type >= 0; type--)
5545                                         dquot_quota_off(sb, type);
5546 
5547                                 ext4_warning(sb,
5548                                         "Failed to enable quota tracking "
5549                                         "(type=%d, err=%d). Please run "
5550                                         "e2fsck to fix.", type, err);
5551                                 return err;
5552                         }
5553                 }
5554         }
5555         return 0;
5556 }
5557 
5558 static int ext4_quota_off(struct super_block *sb, int type)
5559 {
5560         struct inode *inode = sb_dqopt(sb)->files[type];
5561         handle_t *handle;
5562         int err;
5563 
5564         /* Force all delayed allocation blocks to be allocated.
5565          * Caller already holds s_umount sem */
5566         if (test_opt(sb, DELALLOC))
5567                 sync_filesystem(sb);
5568 
5569         if (!inode || !igrab(inode))
5570                 goto out;
5571 
5572         err = dquot_quota_off(sb, type);
5573         if (err || ext4_has_feature_quota(sb))
5574                 goto out_put;
5575 
5576         inode_lock(inode);
5577         /*
5578          * Update modification times of quota files when userspace can
5579          * start looking at them. If we fail, we return success anyway since
5580          * this is not a hard failure and quotas are already disabled.
5581          */
5582         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5583         if (IS_ERR(handle))
5584                 goto out_unlock;
5585         EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5586         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5587         inode->i_mtime = inode->i_ctime = current_time(inode);
5588         ext4_mark_inode_dirty(handle, inode);
5589         ext4_journal_stop(handle);
5590 out_unlock:
5591         inode_unlock(inode);
5592 out_put:
5593         lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5594         iput(inode);
5595         return err;
5596 out:
5597         return dquot_quota_off(sb, type);
5598 }
5599 
5600 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5601  * acquiring the locks... As quota files are never truncated and quota code
5602  * itself serializes the operations (and no one else should touch the files)
5603  * we don't have to be afraid of races */
5604 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5605                                size_t len, loff_t off)
5606 {
5607         struct inode *inode = sb_dqopt(sb)->files[type];
5608         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5609         int offset = off & (sb->s_blocksize - 1);
5610         int tocopy;
5611         size_t toread;
5612         struct buffer_head *bh;
5613         loff_t i_size = i_size_read(inode);
5614 
5615         if (off > i_size)
5616                 return 0;
5617         if (off+len > i_size)
5618                 len = i_size-off;
5619         toread = len;
5620         while (toread > 0) {
5621                 tocopy = sb->s_blocksize - offset < toread ?
5622                                 sb->s_blocksize - offset : toread;
5623                 bh = ext4_bread(NULL, inode, blk, 0);
5624                 if (IS_ERR(bh))
5625                         return PTR_ERR(bh);
5626                 if (!bh)        /* A hole? */
5627                         memset(data, 0, tocopy);
5628                 else
5629                         memcpy(data, bh->b_data+offset, tocopy);
5630                 brelse(bh);
5631                 offset = 0;
5632                 toread -= tocopy;
5633                 data += tocopy;
5634                 blk++;
5635         }
5636         return len;
5637 }
5638 
5639 /* Write to quotafile (we know the transaction is already started and has
5640  * enough credits) */
5641 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5642                                 const char *data, size_t len, loff_t off)
5643 {
5644         struct inode *inode = sb_dqopt(sb)->files[type];
5645         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5646         int err, offset = off & (sb->s_blocksize - 1);
5647         int retries = 0;
5648         struct buffer_head *bh;
5649         handle_t *handle = journal_current_handle();
5650 
5651         if (EXT4_SB(sb)->s_journal && !handle) {
5652                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5653                         " cancelled because transaction is not started",
5654                         (unsigned long long)off, (unsigned long long)len);
5655                 return -EIO;
5656         }
5657         /*
5658          * Since we account only one data block in transaction credits,
5659          * then it is impossible to cross a block boundary.
5660          */
5661         if (sb->s_blocksize - offset < len) {
5662                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5663                         " cancelled because not block aligned",
5664                         (unsigned long long)off, (unsigned long long)len);
5665                 return -EIO;
5666         }
5667 
5668         do {
5669                 bh = ext4_bread(handle, inode, blk,
5670                                 EXT4_GET_BLOCKS_CREATE |
5671                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5672         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5673                  ext4_should_retry_alloc(inode->i_sb, &retries));
5674         if (IS_ERR(bh))
5675                 return PTR_ERR(bh);
5676         if (!bh)
5677                 goto out;
5678         BUFFER_TRACE(bh, "get write access");
5679         err = ext4_journal_get_write_access(handle, bh);
5680         if (err) {
5681                 brelse(bh);
5682                 return err;
5683         }
5684         lock_buffer(bh);
5685         memcpy(bh->b_data+offset, data, len);
5686         flush_dcache_page(bh->b_page);
5687         unlock_buffer(bh);
5688         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5689         brelse(bh);
5690 out:
5691         if (inode->i_size < off + len) {
5692                 i_size_write(inode, off + len);
5693                 EXT4_I(inode)->i_disksize = inode->i_size;
5694                 ext4_mark_inode_dirty(handle, inode);
5695         }
5696         return len;
5697 }
5698 
5699 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5700 {
5701         const struct quota_format_ops   *ops;
5702 
5703         if (!sb_has_quota_loaded(sb, qid->type))
5704                 return -ESRCH;
5705         ops = sb_dqopt(sb)->ops[qid->type];
5706         if (!ops || !ops->get_next_id)
5707                 return -ENOSYS;
5708         return dquot_get_next_id(sb, qid);
5709 }
5710 #endif
5711 
5712 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5713                        const char *dev_name, void *data)
5714 {
5715         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5716 }
5717 
5718 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5719 static inline void register_as_ext2(void)
5720 {
5721         int err = register_filesystem(&ext2_fs_type);
5722         if (err)
5723                 printk(KERN_WARNING
5724                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5725 }
5726 
5727 static inline void unregister_as_ext2(void)
5728 {
5729         unregister_filesystem(&ext2_fs_type);
5730 }
5731 
5732 static inline int ext2_feature_set_ok(struct super_block *sb)
5733 {
5734         if (ext4_has_unknown_ext2_incompat_features(sb))
5735                 return 0;
5736         if (sb_rdonly(sb))
5737                 return 1;
5738         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5739                 return 0;
5740         return 1;
5741 }
5742 #else
5743 static inline void register_as_ext2(void) { }
5744 static inline void unregister_as_ext2(void) { }
5745 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5746 #endif
5747 
5748 static inline void register_as_ext3(void)
5749 {
5750         int err = register_filesystem(&ext3_fs_type);
5751         if (err)
5752                 printk(KERN_WARNING
5753                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5754 }
5755 
5756 static inline void unregister_as_ext3(void)
5757 {
5758         unregister_filesystem(&ext3_fs_type);
5759 }
5760 
5761 static inline int ext3_feature_set_ok(struct super_block *sb)
5762 {
5763         if (ext4_has_unknown_ext3_incompat_features(sb))
5764                 return 0;
5765         if (!ext4_has_feature_journal(sb))
5766                 return 0;
5767         if (sb_rdonly(sb))
5768                 return 1;
5769         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5770                 return 0;
5771         return 1;
5772 }
5773 
5774 static struct file_system_type ext4_fs_type = {
5775         .owner          = THIS_MODULE,
5776         .name           = "ext4",
5777         .mount          = ext4_mount,
5778         .kill_sb        = kill_block_super,
5779         .fs_flags       = FS_REQUIRES_DEV,
5780 };
5781 MODULE_ALIAS_FS("ext4");
5782 
5783 /* Shared across all ext4 file systems */
5784 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5785 
5786 static int __init ext4_init_fs(void)
5787 {
5788         int i, err;
5789 
5790         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5791         ext4_li_info = NULL;
5792         mutex_init(&ext4_li_mtx);
5793 
5794         /* Build-time check for flags consistency */
5795         ext4_check_flag_values();
5796 
5797         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5798                 init_waitqueue_head(&ext4__ioend_wq[i]);
5799 
5800         err = ext4_init_es();
5801         if (err)
5802                 return err;
5803 
5804         err = ext4_init_pageio();
5805         if (err)
5806                 goto out5;
5807 
5808         err = ext4_init_system_zone();
5809         if (err)
5810                 goto out4;
5811 
5812         err = ext4_init_sysfs();
5813         if (err)
5814                 goto out3;
5815 
5816         err = ext4_init_mballoc();
5817         if (err)
5818                 goto out2;
5819         err = init_inodecache();
5820         if (err)
5821                 goto out1;
5822         register_as_ext3();
5823         register_as_ext2();
5824         err = register_filesystem(&