8bb9e2d3e4b8dc69cdeb84086dea2f4bcfc4a519
[pandora-kernel.git] / fs / ext4 / super.c
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/jbd2.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/parser.h>
29 #include <linux/smp_lock.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/proc_fs.h>
39 #include <linux/ctype.h>
40 #include <linux/log2.h>
41 #include <linux/crc16.h>
42 #include <asm/uaccess.h>
43
44 #include "ext4.h"
45 #include "ext4_jbd2.h"
46 #include "xattr.h"
47 #include "acl.h"
48
49 #define CREATE_TRACE_POINTS
50 #include <trace/events/ext4.h>
51
52 static int default_mb_history_length = 1000;
53
54 module_param_named(default_mb_history_length, default_mb_history_length,
55                    int, 0644);
56 MODULE_PARM_DESC(default_mb_history_length,
57                  "Default number of entries saved for mb_history");
58
59 struct proc_dir_entry *ext4_proc_root;
60 static struct kset *ext4_kset;
61
62 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
63                              unsigned long journal_devnum);
64 static int ext4_commit_super(struct super_block *sb, int sync);
65 static void ext4_mark_recovery_complete(struct super_block *sb,
66                                         struct ext4_super_block *es);
67 static void ext4_clear_journal_err(struct super_block *sb,
68                                    struct ext4_super_block *es);
69 static int ext4_sync_fs(struct super_block *sb, int wait);
70 static const char *ext4_decode_error(struct super_block *sb, int errno,
71                                      char nbuf[16]);
72 static int ext4_remount(struct super_block *sb, int *flags, char *data);
73 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
74 static int ext4_unfreeze(struct super_block *sb);
75 static void ext4_write_super(struct super_block *sb);
76 static int ext4_freeze(struct super_block *sb);
77
78
79 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
80                                struct ext4_group_desc *bg)
81 {
82         return le32_to_cpu(bg->bg_block_bitmap_lo) |
83                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
84                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
85 }
86
87 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
88                                struct ext4_group_desc *bg)
89 {
90         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
91                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
92                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
93 }
94
95 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
96                               struct ext4_group_desc *bg)
97 {
98         return le32_to_cpu(bg->bg_inode_table_lo) |
99                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
100                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
101 }
102
103 __u32 ext4_free_blks_count(struct super_block *sb,
104                               struct ext4_group_desc *bg)
105 {
106         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
107                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
108                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
109 }
110
111 __u32 ext4_free_inodes_count(struct super_block *sb,
112                               struct ext4_group_desc *bg)
113 {
114         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
115                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
116                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
117 }
118
119 __u32 ext4_used_dirs_count(struct super_block *sb,
120                               struct ext4_group_desc *bg)
121 {
122         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
123                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
124                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
125 }
126
127 __u32 ext4_itable_unused_count(struct super_block *sb,
128                               struct ext4_group_desc *bg)
129 {
130         return le16_to_cpu(bg->bg_itable_unused_lo) |
131                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
132                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
133 }
134
135 void ext4_block_bitmap_set(struct super_block *sb,
136                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
137 {
138         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
139         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
140                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
141 }
142
143 void ext4_inode_bitmap_set(struct super_block *sb,
144                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
145 {
146         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
147         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
148                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
149 }
150
151 void ext4_inode_table_set(struct super_block *sb,
152                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
153 {
154         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
155         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
156                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
157 }
158
159 void ext4_free_blks_set(struct super_block *sb,
160                           struct ext4_group_desc *bg, __u32 count)
161 {
162         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
163         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
164                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
165 }
166
167 void ext4_free_inodes_set(struct super_block *sb,
168                           struct ext4_group_desc *bg, __u32 count)
169 {
170         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
171         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
172                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
173 }
174
175 void ext4_used_dirs_set(struct super_block *sb,
176                           struct ext4_group_desc *bg, __u32 count)
177 {
178         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
179         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
180                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
181 }
182
183 void ext4_itable_unused_set(struct super_block *sb,
184                           struct ext4_group_desc *bg, __u32 count)
185 {
186         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
187         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
188                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
189 }
190
191 /*
192  * Wrappers for jbd2_journal_start/end.
193  *
194  * The only special thing we need to do here is to make sure that all
195  * journal_end calls result in the superblock being marked dirty, so
196  * that sync() will call the filesystem's write_super callback if
197  * appropriate.
198  */
199 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
200 {
201         journal_t *journal;
202
203         if (sb->s_flags & MS_RDONLY)
204                 return ERR_PTR(-EROFS);
205
206         /* Special case here: if the journal has aborted behind our
207          * backs (eg. EIO in the commit thread), then we still need to
208          * take the FS itself readonly cleanly. */
209         journal = EXT4_SB(sb)->s_journal;
210         if (journal) {
211                 if (is_journal_aborted(journal)) {
212                         ext4_abort(sb, __func__, "Detected aborted journal");
213                         return ERR_PTR(-EROFS);
214                 }
215                 return jbd2_journal_start(journal, nblocks);
216         }
217         /*
218          * We're not journaling, return the appropriate indication.
219          */
220         current->journal_info = EXT4_NOJOURNAL_HANDLE;
221         return current->journal_info;
222 }
223
224 /*
225  * The only special thing we need to do here is to make sure that all
226  * jbd2_journal_stop calls result in the superblock being marked dirty, so
227  * that sync() will call the filesystem's write_super callback if
228  * appropriate.
229  */
230 int __ext4_journal_stop(const char *where, handle_t *handle)
231 {
232         struct super_block *sb;
233         int err;
234         int rc;
235
236         if (!ext4_handle_valid(handle)) {
237                 /*
238                  * Do this here since we don't call jbd2_journal_stop() in
239                  * no-journal mode.
240                  */
241                 current->journal_info = NULL;
242                 return 0;
243         }
244         sb = handle->h_transaction->t_journal->j_private;
245         err = handle->h_err;
246         rc = jbd2_journal_stop(handle);
247
248         if (!err)
249                 err = rc;
250         if (err)
251                 __ext4_std_error(sb, where, err);
252         return err;
253 }
254
255 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
256                 struct buffer_head *bh, handle_t *handle, int err)
257 {
258         char nbuf[16];
259         const char *errstr = ext4_decode_error(NULL, err, nbuf);
260
261         BUG_ON(!ext4_handle_valid(handle));
262
263         if (bh)
264                 BUFFER_TRACE(bh, "abort");
265
266         if (!handle->h_err)
267                 handle->h_err = err;
268
269         if (is_handle_aborted(handle))
270                 return;
271
272         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
273                caller, errstr, err_fn);
274
275         jbd2_journal_abort_handle(handle);
276 }
277
278 /* Deal with the reporting of failure conditions on a filesystem such as
279  * inconsistencies detected or read IO failures.
280  *
281  * On ext2, we can store the error state of the filesystem in the
282  * superblock.  That is not possible on ext4, because we may have other
283  * write ordering constraints on the superblock which prevent us from
284  * writing it out straight away; and given that the journal is about to
285  * be aborted, we can't rely on the current, or future, transactions to
286  * write out the superblock safely.
287  *
288  * We'll just use the jbd2_journal_abort() error code to record an error in
289  * the journal instead.  On recovery, the journal will compain about
290  * that error until we've noted it down and cleared it.
291  */
292
293 static void ext4_handle_error(struct super_block *sb)
294 {
295         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
296
297         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
298         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
299
300         if (sb->s_flags & MS_RDONLY)
301                 return;
302
303         if (!test_opt(sb, ERRORS_CONT)) {
304                 journal_t *journal = EXT4_SB(sb)->s_journal;
305
306                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
307                 if (journal)
308                         jbd2_journal_abort(journal, -EIO);
309         }
310         if (test_opt(sb, ERRORS_RO)) {
311                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
312                 sb->s_flags |= MS_RDONLY;
313         }
314         ext4_commit_super(sb, 1);
315         if (test_opt(sb, ERRORS_PANIC))
316                 panic("EXT4-fs (device %s): panic forced after error\n",
317                         sb->s_id);
318 }
319
320 void ext4_error(struct super_block *sb, const char *function,
321                 const char *fmt, ...)
322 {
323         va_list args;
324
325         va_start(args, fmt);
326         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
327         vprintk(fmt, args);
328         printk("\n");
329         va_end(args);
330
331         ext4_handle_error(sb);
332 }
333
334 static const char *ext4_decode_error(struct super_block *sb, int errno,
335                                      char nbuf[16])
336 {
337         char *errstr = NULL;
338
339         switch (errno) {
340         case -EIO:
341                 errstr = "IO failure";
342                 break;
343         case -ENOMEM:
344                 errstr = "Out of memory";
345                 break;
346         case -EROFS:
347                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
348                         errstr = "Journal has aborted";
349                 else
350                         errstr = "Readonly filesystem";
351                 break;
352         default:
353                 /* If the caller passed in an extra buffer for unknown
354                  * errors, textualise them now.  Else we just return
355                  * NULL. */
356                 if (nbuf) {
357                         /* Check for truncated error codes... */
358                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
359                                 errstr = nbuf;
360                 }
361                 break;
362         }
363
364         return errstr;
365 }
366
367 /* __ext4_std_error decodes expected errors from journaling functions
368  * automatically and invokes the appropriate error response.  */
369
370 void __ext4_std_error(struct super_block *sb, const char *function, int errno)
371 {
372         char nbuf[16];
373         const char *errstr;
374
375         /* Special case: if the error is EROFS, and we're not already
376          * inside a transaction, then there's really no point in logging
377          * an error. */
378         if (errno == -EROFS && journal_current_handle() == NULL &&
379             (sb->s_flags & MS_RDONLY))
380                 return;
381
382         errstr = ext4_decode_error(sb, errno, nbuf);
383         printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
384                sb->s_id, function, errstr);
385
386         ext4_handle_error(sb);
387 }
388
389 /*
390  * ext4_abort is a much stronger failure handler than ext4_error.  The
391  * abort function may be used to deal with unrecoverable failures such
392  * as journal IO errors or ENOMEM at a critical moment in log management.
393  *
394  * We unconditionally force the filesystem into an ABORT|READONLY state,
395  * unless the error response on the fs has been set to panic in which
396  * case we take the easy way out and panic immediately.
397  */
398
399 void ext4_abort(struct super_block *sb, const char *function,
400                 const char *fmt, ...)
401 {
402         va_list args;
403
404         va_start(args, fmt);
405         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
406         vprintk(fmt, args);
407         printk("\n");
408         va_end(args);
409
410         if (test_opt(sb, ERRORS_PANIC))
411                 panic("EXT4-fs panic from previous error\n");
412
413         if (sb->s_flags & MS_RDONLY)
414                 return;
415
416         ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
417         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
418         sb->s_flags |= MS_RDONLY;
419         EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
420         if (EXT4_SB(sb)->s_journal)
421                 jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
422 }
423
424 void ext4_msg (struct super_block * sb, const char *prefix,
425                    const char *fmt, ...)
426 {
427         va_list args;
428
429         va_start(args, fmt);
430         printk("%sEXT4-fs (%s): ", prefix, sb->s_id);
431         vprintk(fmt, args);
432         printk("\n");
433         va_end(args);
434 }
435
436 void ext4_warning(struct super_block *sb, const char *function,
437                   const char *fmt, ...)
438 {
439         va_list args;
440
441         va_start(args, fmt);
442         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
443                sb->s_id, function);
444         vprintk(fmt, args);
445         printk("\n");
446         va_end(args);
447 }
448
449 void ext4_grp_locked_error(struct super_block *sb, ext4_group_t grp,
450                            const char *function, const char *fmt, ...)
451 __releases(bitlock)
452 __acquires(bitlock)
453 {
454         va_list args;
455         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
456
457         va_start(args, fmt);
458         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
459         vprintk(fmt, args);
460         printk("\n");
461         va_end(args);
462
463         if (test_opt(sb, ERRORS_CONT)) {
464                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
465                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
466                 ext4_commit_super(sb, 0);
467                 return;
468         }
469         ext4_unlock_group(sb, grp);
470         ext4_handle_error(sb);
471         /*
472          * We only get here in the ERRORS_RO case; relocking the group
473          * may be dangerous, but nothing bad will happen since the
474          * filesystem will have already been marked read/only and the
475          * journal has been aborted.  We return 1 as a hint to callers
476          * who might what to use the return value from
477          * ext4_grp_locked_error() to distinguish beween the
478          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
479          * aggressively from the ext4 function in question, with a
480          * more appropriate error code.
481          */
482         ext4_lock_group(sb, grp);
483         return;
484 }
485
486 void ext4_update_dynamic_rev(struct super_block *sb)
487 {
488         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
489
490         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
491                 return;
492
493         ext4_warning(sb, __func__,
494                      "updating to rev %d because of new feature flag, "
495                      "running e2fsck is recommended",
496                      EXT4_DYNAMIC_REV);
497
498         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
499         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
500         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
501         /* leave es->s_feature_*compat flags alone */
502         /* es->s_uuid will be set by e2fsck if empty */
503
504         /*
505          * The rest of the superblock fields should be zero, and if not it
506          * means they are likely already in use, so leave them alone.  We
507          * can leave it up to e2fsck to clean up any inconsistencies there.
508          */
509 }
510
511 /*
512  * Open the external journal device
513  */
514 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
515 {
516         struct block_device *bdev;
517         char b[BDEVNAME_SIZE];
518
519         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
520         if (IS_ERR(bdev))
521                 goto fail;
522         return bdev;
523
524 fail:
525         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
526                         __bdevname(dev, b), PTR_ERR(bdev));
527         return NULL;
528 }
529
530 /*
531  * Release the journal device
532  */
533 static int ext4_blkdev_put(struct block_device *bdev)
534 {
535         bd_release(bdev);
536         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
537 }
538
539 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
540 {
541         struct block_device *bdev;
542         int ret = -ENODEV;
543
544         bdev = sbi->journal_bdev;
545         if (bdev) {
546                 ret = ext4_blkdev_put(bdev);
547                 sbi->journal_bdev = NULL;
548         }
549         return ret;
550 }
551
552 static inline struct inode *orphan_list_entry(struct list_head *l)
553 {
554         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
555 }
556
557 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
558 {
559         struct list_head *l;
560
561         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
562                  le32_to_cpu(sbi->s_es->s_last_orphan));
563
564         printk(KERN_ERR "sb_info orphan list:\n");
565         list_for_each(l, &sbi->s_orphan) {
566                 struct inode *inode = orphan_list_entry(l);
567                 printk(KERN_ERR "  "
568                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
569                        inode->i_sb->s_id, inode->i_ino, inode,
570                        inode->i_mode, inode->i_nlink,
571                        NEXT_ORPHAN(inode));
572         }
573 }
574
575 static void ext4_put_super(struct super_block *sb)
576 {
577         struct ext4_sb_info *sbi = EXT4_SB(sb);
578         struct ext4_super_block *es = sbi->s_es;
579         int i, err;
580
581         lock_super(sb);
582         lock_kernel();
583         if (sb->s_dirt)
584                 ext4_commit_super(sb, 1);
585
586         ext4_release_system_zone(sb);
587         ext4_mb_release(sb);
588         ext4_ext_release(sb);
589         ext4_xattr_put_super(sb);
590         if (sbi->s_journal) {
591                 err = jbd2_journal_destroy(sbi->s_journal);
592                 sbi->s_journal = NULL;
593                 if (err < 0)
594                         ext4_abort(sb, __func__,
595                                    "Couldn't clean up the journal");
596         }
597         if (!(sb->s_flags & MS_RDONLY)) {
598                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
599                 es->s_state = cpu_to_le16(sbi->s_mount_state);
600                 ext4_commit_super(sb, 1);
601         }
602         if (sbi->s_proc) {
603                 remove_proc_entry(sb->s_id, ext4_proc_root);
604         }
605         kobject_del(&sbi->s_kobj);
606
607         for (i = 0; i < sbi->s_gdb_count; i++)
608                 brelse(sbi->s_group_desc[i]);
609         kfree(sbi->s_group_desc);
610         if (is_vmalloc_addr(sbi->s_flex_groups))
611                 vfree(sbi->s_flex_groups);
612         else
613                 kfree(sbi->s_flex_groups);
614         percpu_counter_destroy(&sbi->s_freeblocks_counter);
615         percpu_counter_destroy(&sbi->s_freeinodes_counter);
616         percpu_counter_destroy(&sbi->s_dirs_counter);
617         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
618         brelse(sbi->s_sbh);
619 #ifdef CONFIG_QUOTA
620         for (i = 0; i < MAXQUOTAS; i++)
621                 kfree(sbi->s_qf_names[i]);
622 #endif
623
624         /* Debugging code just in case the in-memory inode orphan list
625          * isn't empty.  The on-disk one can be non-empty if we've
626          * detected an error and taken the fs readonly, but the
627          * in-memory list had better be clean by this point. */
628         if (!list_empty(&sbi->s_orphan))
629                 dump_orphan_list(sb, sbi);
630         J_ASSERT(list_empty(&sbi->s_orphan));
631
632         invalidate_bdev(sb->s_bdev);
633         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
634                 /*
635                  * Invalidate the journal device's buffers.  We don't want them
636                  * floating about in memory - the physical journal device may
637                  * hotswapped, and it breaks the `ro-after' testing code.
638                  */
639                 sync_blockdev(sbi->journal_bdev);
640                 invalidate_bdev(sbi->journal_bdev);
641                 ext4_blkdev_remove(sbi);
642         }
643         sb->s_fs_info = NULL;
644         /*
645          * Now that we are completely done shutting down the
646          * superblock, we need to actually destroy the kobject.
647          */
648         unlock_kernel();
649         unlock_super(sb);
650         kobject_put(&sbi->s_kobj);
651         wait_for_completion(&sbi->s_kobj_unregister);
652         kfree(sbi->s_blockgroup_lock);
653         kfree(sbi);
654 }
655
656 static struct kmem_cache *ext4_inode_cachep;
657
658 /*
659  * Called inside transaction, so use GFP_NOFS
660  */
661 static struct inode *ext4_alloc_inode(struct super_block *sb)
662 {
663         struct ext4_inode_info *ei;
664
665         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
666         if (!ei)
667                 return NULL;
668
669 #ifdef CONFIG_EXT4_FS_POSIX_ACL
670         ei->i_acl = EXT4_ACL_NOT_CACHED;
671         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
672 #endif
673         ei->vfs_inode.i_version = 1;
674         ei->vfs_inode.i_data.writeback_index = 0;
675         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
676         INIT_LIST_HEAD(&ei->i_prealloc_list);
677         spin_lock_init(&ei->i_prealloc_lock);
678         /*
679          * Note:  We can be called before EXT4_SB(sb)->s_journal is set,
680          * therefore it can be null here.  Don't check it, just initialize
681          * jinode.
682          */
683         jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
684         ei->i_reserved_data_blocks = 0;
685         ei->i_reserved_meta_blocks = 0;
686         ei->i_allocated_meta_blocks = 0;
687         ei->i_delalloc_reserved_flag = 0;
688         spin_lock_init(&(ei->i_block_reservation_lock));
689
690         return &ei->vfs_inode;
691 }
692
693 static void ext4_destroy_inode(struct inode *inode)
694 {
695         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
696                 ext4_msg(inode->i_sb, KERN_ERR,
697                          "Inode %lu (%p): orphan list check failed!",
698                          inode->i_ino, EXT4_I(inode));
699                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
700                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
701                                 true);
702                 dump_stack();
703         }
704         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
705 }
706
707 static void init_once(void *foo)
708 {
709         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
710
711         INIT_LIST_HEAD(&ei->i_orphan);
712 #ifdef CONFIG_EXT4_FS_XATTR
713         init_rwsem(&ei->xattr_sem);
714 #endif
715         init_rwsem(&ei->i_data_sem);
716         inode_init_once(&ei->vfs_inode);
717 }
718
719 static int init_inodecache(void)
720 {
721         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
722                                              sizeof(struct ext4_inode_info),
723                                              0, (SLAB_RECLAIM_ACCOUNT|
724                                                 SLAB_MEM_SPREAD),
725                                              init_once);
726         if (ext4_inode_cachep == NULL)
727                 return -ENOMEM;
728         return 0;
729 }
730
731 static void destroy_inodecache(void)
732 {
733         kmem_cache_destroy(ext4_inode_cachep);
734 }
735
736 static void ext4_clear_inode(struct inode *inode)
737 {
738 #ifdef CONFIG_EXT4_FS_POSIX_ACL
739         if (EXT4_I(inode)->i_acl &&
740                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
741                 posix_acl_release(EXT4_I(inode)->i_acl);
742                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
743         }
744         if (EXT4_I(inode)->i_default_acl &&
745                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
746                 posix_acl_release(EXT4_I(inode)->i_default_acl);
747                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
748         }
749 #endif
750         ext4_discard_preallocations(inode);
751         if (EXT4_JOURNAL(inode))
752                 jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
753                                        &EXT4_I(inode)->jinode);
754 }
755
756 static inline void ext4_show_quota_options(struct seq_file *seq,
757                                            struct super_block *sb)
758 {
759 #if defined(CONFIG_QUOTA)
760         struct ext4_sb_info *sbi = EXT4_SB(sb);
761
762         if (sbi->s_jquota_fmt)
763                 seq_printf(seq, ",jqfmt=%s",
764                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold" : "vfsv0");
765
766         if (sbi->s_qf_names[USRQUOTA])
767                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
768
769         if (sbi->s_qf_names[GRPQUOTA])
770                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
771
772         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
773                 seq_puts(seq, ",usrquota");
774
775         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
776                 seq_puts(seq, ",grpquota");
777 #endif
778 }
779
780 /*
781  * Show an option if
782  *  - it's set to a non-default value OR
783  *  - if the per-sb default is different from the global default
784  */
785 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
786 {
787         int def_errors;
788         unsigned long def_mount_opts;
789         struct super_block *sb = vfs->mnt_sb;
790         struct ext4_sb_info *sbi = EXT4_SB(sb);
791         struct ext4_super_block *es = sbi->s_es;
792
793         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
794         def_errors     = le16_to_cpu(es->s_errors);
795
796         if (sbi->s_sb_block != 1)
797                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
798         if (test_opt(sb, MINIX_DF))
799                 seq_puts(seq, ",minixdf");
800         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
801                 seq_puts(seq, ",grpid");
802         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
803                 seq_puts(seq, ",nogrpid");
804         if (sbi->s_resuid != EXT4_DEF_RESUID ||
805             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
806                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
807         }
808         if (sbi->s_resgid != EXT4_DEF_RESGID ||
809             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
810                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
811         }
812         if (test_opt(sb, ERRORS_RO)) {
813                 if (def_errors == EXT4_ERRORS_PANIC ||
814                     def_errors == EXT4_ERRORS_CONTINUE) {
815                         seq_puts(seq, ",errors=remount-ro");
816                 }
817         }
818         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
819                 seq_puts(seq, ",errors=continue");
820         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
821                 seq_puts(seq, ",errors=panic");
822         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
823                 seq_puts(seq, ",nouid32");
824         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
825                 seq_puts(seq, ",debug");
826         if (test_opt(sb, OLDALLOC))
827                 seq_puts(seq, ",oldalloc");
828 #ifdef CONFIG_EXT4_FS_XATTR
829         if (test_opt(sb, XATTR_USER) &&
830                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
831                 seq_puts(seq, ",user_xattr");
832         if (!test_opt(sb, XATTR_USER) &&
833             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
834                 seq_puts(seq, ",nouser_xattr");
835         }
836 #endif
837 #ifdef CONFIG_EXT4_FS_POSIX_ACL
838         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
839                 seq_puts(seq, ",acl");
840         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
841                 seq_puts(seq, ",noacl");
842 #endif
843         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
844                 seq_printf(seq, ",commit=%u",
845                            (unsigned) (sbi->s_commit_interval / HZ));
846         }
847         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
848                 seq_printf(seq, ",min_batch_time=%u",
849                            (unsigned) sbi->s_min_batch_time);
850         }
851         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
852                 seq_printf(seq, ",max_batch_time=%u",
853                            (unsigned) sbi->s_min_batch_time);
854         }
855
856         /*
857          * We're changing the default of barrier mount option, so
858          * let's always display its mount state so it's clear what its
859          * status is.
860          */
861         seq_puts(seq, ",barrier=");
862         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
863         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
864                 seq_puts(seq, ",journal_async_commit");
865         if (test_opt(sb, NOBH))
866                 seq_puts(seq, ",nobh");
867         if (test_opt(sb, I_VERSION))
868                 seq_puts(seq, ",i_version");
869         if (!test_opt(sb, DELALLOC))
870                 seq_puts(seq, ",nodelalloc");
871
872
873         if (sbi->s_stripe)
874                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
875         /*
876          * journal mode get enabled in different ways
877          * So just print the value even if we didn't specify it
878          */
879         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
880                 seq_puts(seq, ",data=journal");
881         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
882                 seq_puts(seq, ",data=ordered");
883         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
884                 seq_puts(seq, ",data=writeback");
885
886         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
887                 seq_printf(seq, ",inode_readahead_blks=%u",
888                            sbi->s_inode_readahead_blks);
889
890         if (test_opt(sb, DATA_ERR_ABORT))
891                 seq_puts(seq, ",data_err=abort");
892
893         if (test_opt(sb, NO_AUTO_DA_ALLOC))
894                 seq_puts(seq, ",noauto_da_alloc");
895
896         ext4_show_quota_options(seq, sb);
897
898         return 0;
899 }
900
901 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
902                                         u64 ino, u32 generation)
903 {
904         struct inode *inode;
905
906         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
907                 return ERR_PTR(-ESTALE);
908         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
909                 return ERR_PTR(-ESTALE);
910
911         /* iget isn't really right if the inode is currently unallocated!!
912          *
913          * ext4_read_inode will return a bad_inode if the inode had been
914          * deleted, so we should be safe.
915          *
916          * Currently we don't know the generation for parent directory, so
917          * a generation of 0 means "accept any"
918          */
919         inode = ext4_iget(sb, ino);
920         if (IS_ERR(inode))
921                 return ERR_CAST(inode);
922         if (generation && inode->i_generation != generation) {
923                 iput(inode);
924                 return ERR_PTR(-ESTALE);
925         }
926
927         return inode;
928 }
929
930 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
931                                         int fh_len, int fh_type)
932 {
933         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
934                                     ext4_nfs_get_inode);
935 }
936
937 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
938                                         int fh_len, int fh_type)
939 {
940         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
941                                     ext4_nfs_get_inode);
942 }
943
944 /*
945  * Try to release metadata pages (indirect blocks, directories) which are
946  * mapped via the block device.  Since these pages could have journal heads
947  * which would prevent try_to_free_buffers() from freeing them, we must use
948  * jbd2 layer's try_to_free_buffers() function to release them.
949  */
950 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
951                                  gfp_t wait)
952 {
953         journal_t *journal = EXT4_SB(sb)->s_journal;
954
955         WARN_ON(PageChecked(page));
956         if (!page_has_buffers(page))
957                 return 0;
958         if (journal)
959                 return jbd2_journal_try_to_free_buffers(journal, page,
960                                                         wait & ~__GFP_WAIT);
961         return try_to_free_buffers(page);
962 }
963
964 #ifdef CONFIG_QUOTA
965 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
966 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
967
968 static int ext4_write_dquot(struct dquot *dquot);
969 static int ext4_acquire_dquot(struct dquot *dquot);
970 static int ext4_release_dquot(struct dquot *dquot);
971 static int ext4_mark_dquot_dirty(struct dquot *dquot);
972 static int ext4_write_info(struct super_block *sb, int type);
973 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
974                                 char *path, int remount);
975 static int ext4_quota_on_mount(struct super_block *sb, int type);
976 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
977                                size_t len, loff_t off);
978 static ssize_t ext4_quota_write(struct super_block *sb, int type,
979                                 const char *data, size_t len, loff_t off);
980
981 static struct dquot_operations ext4_quota_operations = {
982         .initialize     = dquot_initialize,
983         .drop           = dquot_drop,
984         .alloc_space    = dquot_alloc_space,
985         .reserve_space  = dquot_reserve_space,
986         .claim_space    = dquot_claim_space,
987         .release_rsv    = dquot_release_reserved_space,
988         .get_reserved_space = ext4_get_reserved_space,
989         .alloc_inode    = dquot_alloc_inode,
990         .free_space     = dquot_free_space,
991         .free_inode     = dquot_free_inode,
992         .transfer       = dquot_transfer,
993         .write_dquot    = ext4_write_dquot,
994         .acquire_dquot  = ext4_acquire_dquot,
995         .release_dquot  = ext4_release_dquot,
996         .mark_dirty     = ext4_mark_dquot_dirty,
997         .write_info     = ext4_write_info,
998         .alloc_dquot    = dquot_alloc,
999         .destroy_dquot  = dquot_destroy,
1000 };
1001
1002 static struct quotactl_ops ext4_qctl_operations = {
1003         .quota_on       = ext4_quota_on,
1004         .quota_off      = vfs_quota_off,
1005         .quota_sync     = vfs_quota_sync,
1006         .get_info       = vfs_get_dqinfo,
1007         .set_info       = vfs_set_dqinfo,
1008         .get_dqblk      = vfs_get_dqblk,
1009         .set_dqblk      = vfs_set_dqblk
1010 };
1011 #endif
1012
1013 static const struct super_operations ext4_sops = {
1014         .alloc_inode    = ext4_alloc_inode,
1015         .destroy_inode  = ext4_destroy_inode,
1016         .write_inode    = ext4_write_inode,
1017         .dirty_inode    = ext4_dirty_inode,
1018         .delete_inode   = ext4_delete_inode,
1019         .put_super      = ext4_put_super,
1020         .sync_fs        = ext4_sync_fs,
1021         .freeze_fs      = ext4_freeze,
1022         .unfreeze_fs    = ext4_unfreeze,
1023         .statfs         = ext4_statfs,
1024         .remount_fs     = ext4_remount,
1025         .clear_inode    = ext4_clear_inode,
1026         .show_options   = ext4_show_options,
1027 #ifdef CONFIG_QUOTA
1028         .quota_read     = ext4_quota_read,
1029         .quota_write    = ext4_quota_write,
1030 #endif
1031         .bdev_try_to_free_page = bdev_try_to_free_page,
1032 };
1033
1034 static const struct super_operations ext4_nojournal_sops = {
1035         .alloc_inode    = ext4_alloc_inode,
1036         .destroy_inode  = ext4_destroy_inode,
1037         .write_inode    = ext4_write_inode,
1038         .dirty_inode    = ext4_dirty_inode,
1039         .delete_inode   = ext4_delete_inode,
1040         .write_super    = ext4_write_super,
1041         .put_super      = ext4_put_super,
1042         .statfs         = ext4_statfs,
1043         .remount_fs     = ext4_remount,
1044         .clear_inode    = ext4_clear_inode,
1045         .show_options   = ext4_show_options,
1046 #ifdef CONFIG_QUOTA
1047         .quota_read     = ext4_quota_read,
1048         .quota_write    = ext4_quota_write,
1049 #endif
1050         .bdev_try_to_free_page = bdev_try_to_free_page,
1051 };
1052
1053 static const struct export_operations ext4_export_ops = {
1054         .fh_to_dentry = ext4_fh_to_dentry,
1055         .fh_to_parent = ext4_fh_to_parent,
1056         .get_parent = ext4_get_parent,
1057 };
1058
1059 enum {
1060         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1061         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1062         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1063         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1064         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1065         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1066         Opt_journal_update, Opt_journal_dev,
1067         Opt_journal_checksum, Opt_journal_async_commit,
1068         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1069         Opt_data_err_abort, Opt_data_err_ignore, Opt_mb_history_length,
1070         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1071         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
1072         Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err, Opt_resize,
1073         Opt_usrquota, Opt_grpquota, Opt_i_version,
1074         Opt_stripe, Opt_delalloc, Opt_nodelalloc,
1075         Opt_block_validity, Opt_noblock_validity,
1076         Opt_inode_readahead_blks, Opt_journal_ioprio
1077 };
1078
1079 static const match_table_t tokens = {
1080         {Opt_bsd_df, "bsddf"},
1081         {Opt_minix_df, "minixdf"},
1082         {Opt_grpid, "grpid"},
1083         {Opt_grpid, "bsdgroups"},
1084         {Opt_nogrpid, "nogrpid"},
1085         {Opt_nogrpid, "sysvgroups"},
1086         {Opt_resgid, "resgid=%u"},
1087         {Opt_resuid, "resuid=%u"},
1088         {Opt_sb, "sb=%u"},
1089         {Opt_err_cont, "errors=continue"},
1090         {Opt_err_panic, "errors=panic"},
1091         {Opt_err_ro, "errors=remount-ro"},
1092         {Opt_nouid32, "nouid32"},
1093         {Opt_debug, "debug"},
1094         {Opt_oldalloc, "oldalloc"},
1095         {Opt_orlov, "orlov"},
1096         {Opt_user_xattr, "user_xattr"},
1097         {Opt_nouser_xattr, "nouser_xattr"},
1098         {Opt_acl, "acl"},
1099         {Opt_noacl, "noacl"},
1100         {Opt_noload, "noload"},
1101         {Opt_nobh, "nobh"},
1102         {Opt_bh, "bh"},
1103         {Opt_commit, "commit=%u"},
1104         {Opt_min_batch_time, "min_batch_time=%u"},
1105         {Opt_max_batch_time, "max_batch_time=%u"},
1106         {Opt_journal_update, "journal=update"},
1107         {Opt_journal_dev, "journal_dev=%u"},
1108         {Opt_journal_checksum, "journal_checksum"},
1109         {Opt_journal_async_commit, "journal_async_commit"},
1110         {Opt_abort, "abort"},
1111         {Opt_data_journal, "data=journal"},
1112         {Opt_data_ordered, "data=ordered"},
1113         {Opt_data_writeback, "data=writeback"},
1114         {Opt_data_err_abort, "data_err=abort"},
1115         {Opt_data_err_ignore, "data_err=ignore"},
1116         {Opt_mb_history_length, "mb_history_length=%u"},
1117         {Opt_offusrjquota, "usrjquota="},
1118         {Opt_usrjquota, "usrjquota=%s"},
1119         {Opt_offgrpjquota, "grpjquota="},
1120         {Opt_grpjquota, "grpjquota=%s"},
1121         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1122         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1123         {Opt_grpquota, "grpquota"},
1124         {Opt_noquota, "noquota"},
1125         {Opt_quota, "quota"},
1126         {Opt_usrquota, "usrquota"},
1127         {Opt_barrier, "barrier=%u"},
1128         {Opt_barrier, "barrier"},
1129         {Opt_nobarrier, "nobarrier"},
1130         {Opt_i_version, "i_version"},
1131         {Opt_stripe, "stripe=%u"},
1132         {Opt_resize, "resize"},
1133         {Opt_delalloc, "delalloc"},
1134         {Opt_nodelalloc, "nodelalloc"},
1135         {Opt_block_validity, "block_validity"},
1136         {Opt_noblock_validity, "noblock_validity"},
1137         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1138         {Opt_journal_ioprio, "journal_ioprio=%u"},
1139         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1140         {Opt_auto_da_alloc, "auto_da_alloc"},
1141         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1142         {Opt_err, NULL},
1143 };
1144
1145 static ext4_fsblk_t get_sb_block(void **data)
1146 {
1147         ext4_fsblk_t    sb_block;
1148         char            *options = (char *) *data;
1149
1150         if (!options || strncmp(options, "sb=", 3) != 0)
1151                 return 1;       /* Default location */
1152
1153         options += 3;
1154         /* TODO: use simple_strtoll with >32bit ext4 */
1155         sb_block = simple_strtoul(options, &options, 0);
1156         if (*options && *options != ',') {
1157                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1158                        (char *) *data);
1159                 return 1;
1160         }
1161         if (*options == ',')
1162                 options++;
1163         *data = (void *) options;
1164
1165         return sb_block;
1166 }
1167
1168 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1169
1170 static int parse_options(char *options, struct super_block *sb,
1171                          unsigned long *journal_devnum,
1172                          unsigned int *journal_ioprio,
1173                          ext4_fsblk_t *n_blocks_count, int is_remount)
1174 {
1175         struct ext4_sb_info *sbi = EXT4_SB(sb);
1176         char *p;
1177         substring_t args[MAX_OPT_ARGS];
1178         int data_opt = 0;
1179         int option;
1180 #ifdef CONFIG_QUOTA
1181         int qtype, qfmt;
1182         char *qname;
1183 #endif
1184
1185         if (!options)
1186                 return 1;
1187
1188         while ((p = strsep(&options, ",")) != NULL) {
1189                 int token;
1190                 if (!*p)
1191                         continue;
1192
1193                 token = match_token(p, tokens, args);
1194                 switch (token) {
1195                 case Opt_bsd_df:
1196                         clear_opt(sbi->s_mount_opt, MINIX_DF);
1197                         break;
1198                 case Opt_minix_df:
1199                         set_opt(sbi->s_mount_opt, MINIX_DF);
1200                         break;
1201                 case Opt_grpid:
1202                         set_opt(sbi->s_mount_opt, GRPID);
1203                         break;
1204                 case Opt_nogrpid:
1205                         clear_opt(sbi->s_mount_opt, GRPID);
1206                         break;
1207                 case Opt_resuid:
1208                         if (match_int(&args[0], &option))
1209                                 return 0;
1210                         sbi->s_resuid = option;
1211                         break;
1212                 case Opt_resgid:
1213                         if (match_int(&args[0], &option))
1214                                 return 0;
1215                         sbi->s_resgid = option;
1216                         break;
1217                 case Opt_sb:
1218                         /* handled by get_sb_block() instead of here */
1219                         /* *sb_block = match_int(&args[0]); */
1220                         break;
1221                 case Opt_err_panic:
1222                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1223                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1224                         set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1225                         break;
1226                 case Opt_err_ro:
1227                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1228                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1229                         set_opt(sbi->s_mount_opt, ERRORS_RO);
1230                         break;
1231                 case Opt_err_cont:
1232                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1233                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1234                         set_opt(sbi->s_mount_opt, ERRORS_CONT);
1235                         break;
1236                 case Opt_nouid32:
1237                         set_opt(sbi->s_mount_opt, NO_UID32);
1238                         break;
1239                 case Opt_debug:
1240                         set_opt(sbi->s_mount_opt, DEBUG);
1241                         break;
1242                 case Opt_oldalloc:
1243                         set_opt(sbi->s_mount_opt, OLDALLOC);
1244                         break;
1245                 case Opt_orlov:
1246                         clear_opt(sbi->s_mount_opt, OLDALLOC);
1247                         break;
1248 #ifdef CONFIG_EXT4_FS_XATTR
1249                 case Opt_user_xattr:
1250                         set_opt(sbi->s_mount_opt, XATTR_USER);
1251                         break;
1252                 case Opt_nouser_xattr:
1253                         clear_opt(sbi->s_mount_opt, XATTR_USER);
1254                         break;
1255 #else
1256                 case Opt_user_xattr:
1257                 case Opt_nouser_xattr:
1258                         ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1259                         break;
1260 #endif
1261 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1262                 case Opt_acl:
1263                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1264                         break;
1265                 case Opt_noacl:
1266                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1267                         break;
1268 #else
1269                 case Opt_acl:
1270                 case Opt_noacl:
1271                         ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1272                         break;
1273 #endif
1274                 case Opt_journal_update:
1275                         /* @@@ FIXME */
1276                         /* Eventually we will want to be able to create
1277                            a journal file here.  For now, only allow the
1278                            user to specify an existing inode to be the
1279                            journal file. */
1280                         if (is_remount) {
1281                                 ext4_msg(sb, KERN_ERR,
1282                                          "Cannot specify journal on remount");
1283                                 return 0;
1284                         }
1285                         set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1286                         break;
1287                 case Opt_journal_dev:
1288                         if (is_remount) {
1289                                 ext4_msg(sb, KERN_ERR,
1290                                         "Cannot specify journal on remount");
1291                                 return 0;
1292                         }
1293                         if (match_int(&args[0], &option))
1294                                 return 0;
1295                         *journal_devnum = option;
1296                         break;
1297                 case Opt_journal_checksum:
1298                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1299                         break;
1300                 case Opt_journal_async_commit:
1301                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1302                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1303                         break;
1304                 case Opt_noload:
1305                         set_opt(sbi->s_mount_opt, NOLOAD);
1306                         break;
1307                 case Opt_commit:
1308                         if (match_int(&args[0], &option))
1309                                 return 0;
1310                         if (option < 0)
1311                                 return 0;
1312                         if (option == 0)
1313                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1314                         sbi->s_commit_interval = HZ * option;
1315                         break;
1316                 case Opt_max_batch_time:
1317                         if (match_int(&args[0], &option))
1318                                 return 0;
1319                         if (option < 0)
1320                                 return 0;
1321                         if (option == 0)
1322                                 option = EXT4_DEF_MAX_BATCH_TIME;
1323                         sbi->s_max_batch_time = option;
1324                         break;
1325                 case Opt_min_batch_time:
1326                         if (match_int(&args[0], &option))
1327                                 return 0;
1328                         if (option < 0)
1329                                 return 0;
1330                         sbi->s_min_batch_time = option;
1331                         break;
1332                 case Opt_data_journal:
1333                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1334                         goto datacheck;
1335                 case Opt_data_ordered:
1336                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1337                         goto datacheck;
1338                 case Opt_data_writeback:
1339                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1340                 datacheck:
1341                         if (is_remount) {
1342                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1343                                                 != data_opt) {
1344                                         ext4_msg(sb, KERN_ERR,
1345                                                 "Cannot change data mode on remount");
1346                                         return 0;
1347                                 }
1348                         } else {
1349                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1350                                 sbi->s_mount_opt |= data_opt;
1351                         }
1352                         break;
1353                 case Opt_data_err_abort:
1354                         set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1355                         break;
1356                 case Opt_data_err_ignore:
1357                         clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1358                         break;
1359                 case Opt_mb_history_length:
1360                         if (match_int(&args[0], &option))
1361                                 return 0;
1362                         if (option < 0)
1363                                 return 0;
1364                         sbi->s_mb_history_max = option;
1365                         break;
1366 #ifdef CONFIG_QUOTA
1367                 case Opt_usrjquota:
1368                         qtype = USRQUOTA;
1369                         goto set_qf_name;
1370                 case Opt_grpjquota:
1371                         qtype = GRPQUOTA;
1372 set_qf_name:
1373                         if (sb_any_quota_loaded(sb) &&
1374                             !sbi->s_qf_names[qtype]) {
1375                                 ext4_msg(sb, KERN_ERR,
1376                                        "Cannot change journaled "
1377                                        "quota options when quota turned on");
1378                                 return 0;
1379                         }
1380                         qname = match_strdup(&args[0]);
1381                         if (!qname) {
1382                                 ext4_msg(sb, KERN_ERR,
1383                                         "Not enough memory for "
1384                                         "storing quotafile name");
1385                                 return 0;
1386                         }
1387                         if (sbi->s_qf_names[qtype] &&
1388                             strcmp(sbi->s_qf_names[qtype], qname)) {
1389                                 ext4_msg(sb, KERN_ERR,
1390                                         "%s quota file already "
1391                                         "specified", QTYPE2NAME(qtype));
1392                                 kfree(qname);
1393                                 return 0;
1394                         }
1395                         sbi->s_qf_names[qtype] = qname;
1396                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1397                                 ext4_msg(sb, KERN_ERR,
1398                                         "quotafile must be on "
1399                                         "filesystem root");
1400                                 kfree(sbi->s_qf_names[qtype]);
1401                                 sbi->s_qf_names[qtype] = NULL;
1402                                 return 0;
1403                         }
1404                         set_opt(sbi->s_mount_opt, QUOTA);
1405                         break;
1406                 case Opt_offusrjquota:
1407                         qtype = USRQUOTA;
1408                         goto clear_qf_name;
1409                 case Opt_offgrpjquota:
1410                         qtype = GRPQUOTA;
1411 clear_qf_name:
1412                         if (sb_any_quota_loaded(sb) &&
1413                             sbi->s_qf_names[qtype]) {
1414                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1415                                         "journaled quota options when "
1416                                         "quota turned on");
1417                                 return 0;
1418                         }
1419                         /*
1420                          * The space will be released later when all options
1421                          * are confirmed to be correct
1422                          */
1423                         sbi->s_qf_names[qtype] = NULL;
1424                         break;
1425                 case Opt_jqfmt_vfsold:
1426                         qfmt = QFMT_VFS_OLD;
1427                         goto set_qf_format;
1428                 case Opt_jqfmt_vfsv0:
1429                         qfmt = QFMT_VFS_V0;
1430 set_qf_format:
1431                         if (sb_any_quota_loaded(sb) &&
1432                             sbi->s_jquota_fmt != qfmt) {
1433                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1434                                         "journaled quota options when "
1435                                         "quota turned on");
1436                                 return 0;
1437                         }
1438                         sbi->s_jquota_fmt = qfmt;
1439                         break;
1440                 case Opt_quota:
1441                 case Opt_usrquota:
1442                         set_opt(sbi->s_mount_opt, QUOTA);
1443                         set_opt(sbi->s_mount_opt, USRQUOTA);
1444                         break;
1445                 case Opt_grpquota:
1446                         set_opt(sbi->s_mount_opt, QUOTA);
1447                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1448                         break;
1449                 case Opt_noquota:
1450                         if (sb_any_quota_loaded(sb)) {
1451                                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1452                                         "options when quota turned on");
1453                                 return 0;
1454                         }
1455                         clear_opt(sbi->s_mount_opt, QUOTA);
1456                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1457                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1458                         break;
1459 #else
1460                 case Opt_quota:
1461                 case Opt_usrquota:
1462                 case Opt_grpquota:
1463                         ext4_msg(sb, KERN_ERR,
1464                                 "quota options not supported");
1465                         break;
1466                 case Opt_usrjquota:
1467                 case Opt_grpjquota:
1468                 case Opt_offusrjquota:
1469                 case Opt_offgrpjquota:
1470                 case Opt_jqfmt_vfsold:
1471                 case Opt_jqfmt_vfsv0:
1472                         ext4_msg(sb, KERN_ERR,
1473                                 "journaled quota options not supported");
1474                         break;
1475                 case Opt_noquota:
1476                         break;
1477 #endif
1478                 case Opt_abort:
1479                         sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1480                         break;
1481                 case Opt_nobarrier:
1482                         clear_opt(sbi->s_mount_opt, BARRIER);
1483                         break;
1484                 case Opt_barrier:
1485                         if (match_int(&args[0], &option)) {
1486                                 set_opt(sbi->s_mount_opt, BARRIER);
1487                                 break;
1488                         }
1489                         if (option)
1490                                 set_opt(sbi->s_mount_opt, BARRIER);
1491                         else
1492                                 clear_opt(sbi->s_mount_opt, BARRIER);
1493                         break;
1494                 case Opt_ignore:
1495                         break;
1496                 case Opt_resize:
1497                         if (!is_remount) {
1498                                 ext4_msg(sb, KERN_ERR,
1499                                         "resize option only available "
1500                                         "for remount");
1501                                 return 0;
1502                         }
1503                         if (match_int(&args[0], &option) != 0)
1504                                 return 0;
1505                         *n_blocks_count = option;
1506                         break;
1507                 case Opt_nobh:
1508                         set_opt(sbi->s_mount_opt, NOBH);
1509                         break;
1510                 case Opt_bh:
1511                         clear_opt(sbi->s_mount_opt, NOBH);
1512                         break;
1513                 case Opt_i_version:
1514                         set_opt(sbi->s_mount_opt, I_VERSION);
1515                         sb->s_flags |= MS_I_VERSION;
1516                         break;
1517                 case Opt_nodelalloc:
1518                         clear_opt(sbi->s_mount_opt, DELALLOC);
1519                         break;
1520                 case Opt_stripe:
1521                         if (match_int(&args[0], &option))
1522                                 return 0;
1523                         if (option < 0)
1524                                 return 0;
1525                         sbi->s_stripe = option;
1526                         break;
1527                 case Opt_delalloc:
1528                         set_opt(sbi->s_mount_opt, DELALLOC);
1529                         break;
1530                 case Opt_block_validity:
1531                         set_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1532                         break;
1533                 case Opt_noblock_validity:
1534                         clear_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1535                         break;
1536                 case Opt_inode_readahead_blks:
1537                         if (match_int(&args[0], &option))
1538                                 return 0;
1539                         if (option < 0 || option > (1 << 30))
1540                                 return 0;
1541                         if (!is_power_of_2(option)) {
1542                                 ext4_msg(sb, KERN_ERR,
1543                                          "EXT4-fs: inode_readahead_blks"
1544                                          " must be a power of 2");
1545                                 return 0;
1546                         }
1547                         sbi->s_inode_readahead_blks = option;
1548                         break;
1549                 case Opt_journal_ioprio:
1550                         if (match_int(&args[0], &option))
1551                                 return 0;
1552                         if (option < 0 || option > 7)
1553                                 break;
1554                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1555                                                             option);
1556                         break;
1557                 case Opt_noauto_da_alloc:
1558                         set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1559                         break;
1560                 case Opt_auto_da_alloc:
1561                         if (match_int(&args[0], &option)) {
1562                                 clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1563                                 break;
1564                         }
1565                         if (option)
1566                                 clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1567                         else
1568                                 set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1569                         break;
1570                 default:
1571                         ext4_msg(sb, KERN_ERR,
1572                                "Unrecognized mount option \"%s\" "
1573                                "or missing value", p);
1574                         return 0;
1575                 }
1576         }
1577 #ifdef CONFIG_QUOTA
1578         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1579                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1580                      sbi->s_qf_names[USRQUOTA])
1581                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1582
1583                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1584                      sbi->s_qf_names[GRPQUOTA])
1585                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1586
1587                 if ((sbi->s_qf_names[USRQUOTA] &&
1588                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1589                     (sbi->s_qf_names[GRPQUOTA] &&
1590                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1591                         ext4_msg(sb, KERN_ERR, "old and new quota "
1592                                         "format mixing");
1593                         return 0;
1594                 }
1595
1596                 if (!sbi->s_jquota_fmt) {
1597                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1598                                         "not specified");
1599                         return 0;
1600                 }
1601         } else {
1602                 if (sbi->s_jquota_fmt) {
1603                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1604                                         "specified with no journaling "
1605                                         "enabled");
1606                         return 0;
1607                 }
1608         }
1609 #endif
1610         return 1;
1611 }
1612
1613 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1614                             int read_only)
1615 {
1616         struct ext4_sb_info *sbi = EXT4_SB(sb);
1617         int res = 0;
1618
1619         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1620                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1621                          "forcing read-only mode");
1622                 res = MS_RDONLY;
1623         }
1624         if (read_only)
1625                 return res;
1626         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1627                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1628                          "running e2fsck is recommended");
1629         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1630                 ext4_msg(sb, KERN_WARNING,
1631                          "warning: mounting fs with errors, "
1632                          "running e2fsck is recommended");
1633         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1634                  le16_to_cpu(es->s_mnt_count) >=
1635                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1636                 ext4_msg(sb, KERN_WARNING,
1637                          "warning: maximal mount count reached, "
1638                          "running e2fsck is recommended");
1639         else if (le32_to_cpu(es->s_checkinterval) &&
1640                 (le32_to_cpu(es->s_lastcheck) +
1641                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1642                 ext4_msg(sb, KERN_WARNING,
1643                          "warning: checktime reached, "
1644                          "running e2fsck is recommended");
1645         if (!sbi->s_journal)
1646                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1647         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1648                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1649         le16_add_cpu(&es->s_mnt_count, 1);
1650         es->s_mtime = cpu_to_le32(get_seconds());
1651         ext4_update_dynamic_rev(sb);
1652         if (sbi->s_journal)
1653                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1654
1655         ext4_commit_super(sb, 1);
1656         if (test_opt(sb, DEBUG))
1657                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1658                                 "bpg=%lu, ipg=%lu, mo=%04x]\n",
1659                         sb->s_blocksize,
1660                         sbi->s_groups_count,
1661                         EXT4_BLOCKS_PER_GROUP(sb),
1662                         EXT4_INODES_PER_GROUP(sb),
1663                         sbi->s_mount_opt);
1664
1665         if (EXT4_SB(sb)->s_journal) {
1666                 ext4_msg(sb, KERN_INFO, "%s journal on %s",
1667                        EXT4_SB(sb)->s_journal->j_inode ? "internal" :
1668                        "external", EXT4_SB(sb)->s_journal->j_devname);
1669         } else {
1670                 ext4_msg(sb, KERN_INFO, "no journal");
1671         }
1672         return res;
1673 }
1674
1675 static int ext4_fill_flex_info(struct super_block *sb)
1676 {
1677         struct ext4_sb_info *sbi = EXT4_SB(sb);
1678         struct ext4_group_desc *gdp = NULL;
1679         ext4_group_t flex_group_count;
1680         ext4_group_t flex_group;
1681         int groups_per_flex = 0;
1682         size_t size;
1683         int i;
1684
1685         if (!sbi->s_es->s_log_groups_per_flex) {
1686                 sbi->s_log_groups_per_flex = 0;
1687                 return 1;
1688         }
1689
1690         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1691         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1692
1693         /* We allocate both existing and potentially added groups */
1694         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1695                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1696                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1697         size = flex_group_count * sizeof(struct flex_groups);
1698         sbi->s_flex_groups = kzalloc(size, GFP_KERNEL);
1699         if (sbi->s_flex_groups == NULL) {
1700                 sbi->s_flex_groups = vmalloc(size);
1701                 if (sbi->s_flex_groups)
1702                         memset(sbi->s_flex_groups, 0, size);
1703         }
1704         if (sbi->s_flex_groups == NULL) {
1705                 ext4_msg(sb, KERN_ERR, "not enough memory for "
1706                                 "%u flex groups", flex_group_count);
1707                 goto failed;
1708         }
1709
1710         for (i = 0; i < sbi->s_groups_count; i++) {
1711                 gdp = ext4_get_group_desc(sb, i, NULL);
1712
1713                 flex_group = ext4_flex_group(sbi, i);
1714                 atomic_set(&sbi->s_flex_groups[flex_group].free_inodes,
1715                            ext4_free_inodes_count(sb, gdp));
1716                 atomic_set(&sbi->s_flex_groups[flex_group].free_blocks,
1717                            ext4_free_blks_count(sb, gdp));
1718                 atomic_set(&sbi->s_flex_groups[flex_group].used_dirs,
1719                            ext4_used_dirs_count(sb, gdp));
1720         }
1721
1722         return 1;
1723 failed:
1724         return 0;
1725 }
1726
1727 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1728                             struct ext4_group_desc *gdp)
1729 {
1730         __u16 crc = 0;
1731
1732         if (sbi->s_es->s_feature_ro_compat &
1733             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1734                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1735                 __le32 le_group = cpu_to_le32(block_group);
1736
1737                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1738                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1739                 crc = crc16(crc, (__u8 *)gdp, offset);
1740                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1741                 /* for checksum of struct ext4_group_desc do the rest...*/
1742                 if ((sbi->s_es->s_feature_incompat &
1743                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1744                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1745                         crc = crc16(crc, (__u8 *)gdp + offset,
1746                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1747                                         offset);
1748         }
1749
1750         return cpu_to_le16(crc);
1751 }
1752
1753 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1754                                 struct ext4_group_desc *gdp)
1755 {
1756         if ((sbi->s_es->s_feature_ro_compat &
1757              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1758             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1759                 return 0;
1760
1761         return 1;
1762 }
1763
1764 /* Called at mount-time, super-block is locked */
1765 static int ext4_check_descriptors(struct super_block *sb)
1766 {
1767         struct ext4_sb_info *sbi = EXT4_SB(sb);
1768         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1769         ext4_fsblk_t last_block;
1770         ext4_fsblk_t block_bitmap;
1771         ext4_fsblk_t inode_bitmap;
1772         ext4_fsblk_t inode_table;
1773         int flexbg_flag = 0;
1774         ext4_group_t i;
1775
1776         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1777                 flexbg_flag = 1;
1778
1779         ext4_debug("Checking group descriptors");
1780
1781         for (i = 0; i < sbi->s_groups_count; i++) {
1782                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1783
1784                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1785                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1786                 else
1787                         last_block = first_block +
1788                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1789
1790                 block_bitmap = ext4_block_bitmap(sb, gdp);
1791                 if (block_bitmap < first_block || block_bitmap > last_block) {
1792                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1793                                "Block bitmap for group %u not in group "
1794                                "(block %llu)!", i, block_bitmap);
1795                         return 0;
1796                 }
1797                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1798                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
1799                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1800                                "Inode bitmap for group %u not in group "
1801                                "(block %llu)!", i, inode_bitmap);
1802                         return 0;
1803                 }
1804                 inode_table = ext4_inode_table(sb, gdp);
1805                 if (inode_table < first_block ||
1806                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
1807                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1808                                "Inode table for group %u not in group "
1809                                "(block %llu)!", i, inode_table);
1810                         return 0;
1811                 }
1812                 ext4_lock_group(sb, i);
1813                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1814                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1815                                  "Checksum for group %u failed (%u!=%u)",
1816                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1817                                      gdp)), le16_to_cpu(gdp->bg_checksum));
1818                         if (!(sb->s_flags & MS_RDONLY)) {
1819                                 ext4_unlock_group(sb, i);
1820                                 return 0;
1821                         }
1822                 }
1823                 ext4_unlock_group(sb, i);
1824                 if (!flexbg_flag)
1825                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1826         }
1827
1828         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1829         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
1830         return 1;
1831 }
1832
1833 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1834  * the superblock) which were deleted from all directories, but held open by
1835  * a process at the time of a crash.  We walk the list and try to delete these
1836  * inodes at recovery time (only with a read-write filesystem).
1837  *
1838  * In order to keep the orphan inode chain consistent during traversal (in
1839  * case of crash during recovery), we link each inode into the superblock
1840  * orphan list_head and handle it the same way as an inode deletion during
1841  * normal operation (which journals the operations for us).
1842  *
1843  * We only do an iget() and an iput() on each inode, which is very safe if we
1844  * accidentally point at an in-use or already deleted inode.  The worst that
1845  * can happen in this case is that we get a "bit already cleared" message from
1846  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1847  * e2fsck was run on this filesystem, and it must have already done the orphan
1848  * inode cleanup for us, so we can safely abort without any further action.
1849  */
1850 static void ext4_orphan_cleanup(struct super_block *sb,
1851                                 struct ext4_super_block *es)
1852 {
1853         unsigned int s_flags = sb->s_flags;
1854         int nr_orphans = 0, nr_truncates = 0;
1855 #ifdef CONFIG_QUOTA
1856         int i;
1857 #endif
1858         if (!es->s_last_orphan) {
1859                 jbd_debug(4, "no orphan inodes to clean up\n");
1860                 return;
1861         }
1862
1863         if (bdev_read_only(sb->s_bdev)) {
1864                 ext4_msg(sb, KERN_ERR, "write access "
1865                         "unavailable, skipping orphan cleanup");
1866                 return;
1867         }
1868
1869         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1870                 if (es->s_last_orphan)
1871                         jbd_debug(1, "Errors on filesystem, "
1872                                   "clearing orphan list.\n");
1873                 es->s_last_orphan = 0;
1874                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1875                 return;
1876         }
1877
1878         if (s_flags & MS_RDONLY) {
1879                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
1880                 sb->s_flags &= ~MS_RDONLY;
1881         }
1882 #ifdef CONFIG_QUOTA
1883         /* Needed for iput() to work correctly and not trash data */
1884         sb->s_flags |= MS_ACTIVE;
1885         /* Turn on quotas so that they are updated correctly */
1886         for (i = 0; i < MAXQUOTAS; i++) {
1887                 if (EXT4_SB(sb)->s_qf_names[i]) {
1888                         int ret = ext4_quota_on_mount(sb, i);
1889                         if (ret < 0)
1890                                 ext4_msg(sb, KERN_ERR,
1891                                         "Cannot turn on journaled "
1892                                         "quota: error %d", ret);
1893                 }
1894         }
1895 #endif
1896
1897         while (es->s_last_orphan) {
1898                 struct inode *inode;
1899
1900                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1901                 if (IS_ERR(inode)) {
1902                         es->s_last_orphan = 0;
1903                         break;
1904                 }
1905
1906                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1907                 vfs_dq_init(inode);
1908                 if (inode->i_nlink) {
1909                         ext4_msg(sb, KERN_DEBUG,
1910                                 "%s: truncating inode %lu to %lld bytes",
1911                                 __func__, inode->i_ino, inode->i_size);
1912                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
1913                                   inode->i_ino, inode->i_size);
1914                         ext4_truncate(inode);
1915                         nr_truncates++;
1916                 } else {
1917                         ext4_msg(sb, KERN_DEBUG,
1918                                 "%s: deleting unreferenced inode %lu",
1919                                 __func__, inode->i_ino);
1920                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1921                                   inode->i_ino);
1922                         nr_orphans++;
1923                 }
1924                 iput(inode);  /* The delete magic happens here! */
1925         }
1926
1927 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
1928
1929         if (nr_orphans)
1930                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
1931                        PLURAL(nr_orphans));
1932         if (nr_truncates)
1933                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
1934                        PLURAL(nr_truncates));
1935 #ifdef CONFIG_QUOTA
1936         /* Turn quotas off */
1937         for (i = 0; i < MAXQUOTAS; i++) {
1938                 if (sb_dqopt(sb)->files[i])
1939                         vfs_quota_off(sb, i, 0);
1940         }
1941 #endif
1942         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1943 }
1944
1945 /*
1946  * Maximal extent format file size.
1947  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1948  * extent format containers, within a sector_t, and within i_blocks
1949  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1950  * so that won't be a limiting factor.
1951  *
1952  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1953  */
1954 static loff_t ext4_max_size(int blkbits, int has_huge_files)
1955 {
1956         loff_t res;
1957         loff_t upper_limit = MAX_LFS_FILESIZE;
1958
1959         /* small i_blocks in vfs inode? */
1960         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1961                 /*
1962                  * CONFIG_LBDAF is not enabled implies the inode
1963                  * i_block represent total blocks in 512 bytes
1964                  * 32 == size of vfs inode i_blocks * 8
1965                  */
1966                 upper_limit = (1LL << 32) - 1;
1967
1968                 /* total blocks in file system block size */
1969                 upper_limit >>= (blkbits - 9);
1970                 upper_limit <<= blkbits;
1971         }
1972
1973         /* 32-bit extent-start container, ee_block */
1974         res = 1LL << 32;
1975         res <<= blkbits;
1976         res -= 1;
1977
1978         /* Sanity check against vm- & vfs- imposed limits */
1979         if (res > upper_limit)
1980                 res = upper_limit;
1981
1982         return res;
1983 }
1984
1985 /*
1986  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1987  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1988  * We need to be 1 filesystem block less than the 2^48 sector limit.
1989  */
1990 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
1991 {
1992         loff_t res = EXT4_NDIR_BLOCKS;
1993         int meta_blocks;
1994         loff_t upper_limit;
1995         /* This is calculated to be the largest file size for a dense, block
1996          * mapped file such that the file's total number of 512-byte sectors,
1997          * including data and all indirect blocks, does not exceed (2^48 - 1).
1998          *
1999          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2000          * number of 512-byte sectors of the file.
2001          */
2002
2003         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2004                 /*
2005                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2006                  * the inode i_block field represents total file blocks in
2007                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2008                  */
2009                 upper_limit = (1LL << 32) - 1;
2010
2011                 /* total blocks in file system block size */
2012                 upper_limit >>= (bits - 9);
2013
2014         } else {
2015                 /*
2016                  * We use 48 bit ext4_inode i_blocks
2017                  * With EXT4_HUGE_FILE_FL set the i_blocks
2018                  * represent total number of blocks in
2019                  * file system block size
2020                  */
2021                 upper_limit = (1LL << 48) - 1;
2022
2023         }
2024
2025         /* indirect blocks */
2026         meta_blocks = 1;
2027         /* double indirect blocks */
2028         meta_blocks += 1 + (1LL << (bits-2));
2029         /* tripple indirect blocks */
2030         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2031
2032         upper_limit -= meta_blocks;
2033         upper_limit <<= bits;
2034
2035         res += 1LL << (bits-2);
2036         res += 1LL << (2*(bits-2));
2037         res += 1LL << (3*(bits-2));
2038         res <<= bits;
2039         if (res > upper_limit)
2040                 res = upper_limit;
2041
2042         if (res > MAX_LFS_FILESIZE)
2043                 res = MAX_LFS_FILESIZE;
2044
2045         return res;
2046 }
2047
2048 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2049                                    ext4_fsblk_t logical_sb_block, int nr)
2050 {
2051         struct ext4_sb_info *sbi = EXT4_SB(sb);
2052         ext4_group_t bg, first_meta_bg;
2053         int has_super = 0;
2054
2055         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2056
2057         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2058             nr < first_meta_bg)
2059                 return logical_sb_block + nr + 1;
2060         bg = sbi->s_desc_per_block * nr;
2061         if (ext4_bg_has_super(sb, bg))
2062                 has_super = 1;
2063
2064         return (has_super + ext4_group_first_block_no(sb, bg));
2065 }
2066
2067 /**
2068  * ext4_get_stripe_size: Get the stripe size.
2069  * @sbi: In memory super block info
2070  *
2071  * If we have specified it via mount option, then
2072  * use the mount option value. If the value specified at mount time is
2073  * greater than the blocks per group use the super block value.
2074  * If the super block value is greater than blocks per group return 0.
2075  * Allocator needs it be less than blocks per group.
2076  *
2077  */
2078 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2079 {
2080         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2081         unsigned long stripe_width =
2082                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2083
2084         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2085                 return sbi->s_stripe;
2086
2087         if (stripe_width <= sbi->s_blocks_per_group)
2088                 return stripe_width;
2089
2090         if (stride <= sbi->s_blocks_per_group)
2091                 return stride;
2092
2093         return 0;
2094 }
2095
2096 /* sysfs supprt */
2097
2098 struct ext4_attr {
2099         struct attribute attr;
2100         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2101         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *, 
2102                          const char *, size_t);
2103         int offset;
2104 };
2105
2106 static int parse_strtoul(const char *buf,
2107                 unsigned long max, unsigned long *value)
2108 {
2109         char *endp;
2110
2111         while (*buf && isspace(*buf))
2112                 buf++;
2113         *value = simple_strtoul(buf, &endp, 0);
2114         while (*endp && isspace(*endp))
2115                 endp++;
2116         if (*endp || *value > max)
2117                 return -EINVAL;
2118
2119         return 0;
2120 }
2121
2122 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2123                                               struct ext4_sb_info *sbi,
2124                                               char *buf)
2125 {
2126         return snprintf(buf, PAGE_SIZE, "%llu\n",
2127                         (s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2128 }
2129
2130 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2131                                          struct ext4_sb_info *sbi, char *buf)
2132 {
2133         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2134
2135         return snprintf(buf, PAGE_SIZE, "%lu\n",
2136                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2137                          sbi->s_sectors_written_start) >> 1);
2138 }
2139
2140 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2141                                           struct ext4_sb_info *sbi, char *buf)
2142 {
2143         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2144
2145         return snprintf(buf, PAGE_SIZE, "%llu\n",
2146                         sbi->s_kbytes_written + 
2147                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2148                           EXT4_SB(sb)->s_sectors_written_start) >> 1));
2149 }
2150
2151 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2152                                           struct ext4_sb_info *sbi,
2153                                           const char *buf, size_t count)
2154 {
2155         unsigned long t;
2156
2157         if (parse_strtoul(buf, 0x40000000, &t))
2158                 return -EINVAL;
2159
2160         if (!is_power_of_2(t))
2161                 return -EINVAL;
2162
2163         sbi->s_inode_readahead_blks = t;
2164         return count;
2165 }
2166
2167 static ssize_t sbi_ui_show(struct ext4_attr *a,
2168                            struct ext4_sb_info *sbi, char *buf)
2169 {
2170         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2171
2172         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2173 }
2174
2175 static ssize_t sbi_ui_store(struct ext4_attr *a,
2176                             struct ext4_sb_info *sbi,
2177                             const char *buf, size_t count)
2178 {
2179         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2180         unsigned long t;
2181
2182         if (parse_strtoul(buf, 0xffffffff, &t))
2183                 return -EINVAL;
2184         *ui = t;
2185         return count;
2186 }
2187
2188 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2189 static struct ext4_attr ext4_attr_##_name = {                   \
2190         .attr = {.name = __stringify(_name), .mode = _mode },   \
2191         .show   = _show,                                        \
2192         .store  = _store,                                       \
2193         .offset = offsetof(struct ext4_sb_info, _elname),       \
2194 }
2195 #define EXT4_ATTR(name, mode, show, store) \
2196 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2197
2198 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2199 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2200 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2201         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2202 #define ATTR_LIST(name) &ext4_attr_##name.attr
2203
2204 EXT4_RO_ATTR(delayed_allocation_blocks);
2205 EXT4_RO_ATTR(session_write_kbytes);
2206 EXT4_RO_ATTR(lifetime_write_kbytes);
2207 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2208                  inode_readahead_blks_store, s_inode_readahead_blks);
2209 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2210 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2211 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2212 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2213 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2214 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2215 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2216
2217 static struct attribute *ext4_attrs[] = {
2218         ATTR_LIST(delayed_allocation_blocks),
2219         ATTR_LIST(session_write_kbytes),
2220         ATTR_LIST(lifetime_write_kbytes),
2221         ATTR_LIST(inode_readahead_blks),
2222         ATTR_LIST(inode_goal),
2223         ATTR_LIST(mb_stats),
2224         ATTR_LIST(mb_max_to_scan),
2225         ATTR_LIST(mb_min_to_scan),
2226         ATTR_LIST(mb_order2_req),
2227         ATTR_LIST(mb_stream_req),
2228         ATTR_LIST(mb_group_prealloc),
2229         NULL,
2230 };
2231
2232 static ssize_t ext4_attr_show(struct kobject *kobj,
2233                               struct attribute *attr, char *buf)
2234 {
2235         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2236                                                 s_kobj);
2237         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2238
2239         return a->show ? a->show(a, sbi, buf) : 0;
2240 }
2241
2242 static ssize_t ext4_attr_store(struct kobject *kobj,
2243                                struct attribute *attr,
2244                                const char *buf, size_t len)
2245 {
2246         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2247                                                 s_kobj);
2248         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2249
2250         return a->store ? a->store(a, sbi, buf, len) : 0;
2251 }
2252
2253 static void ext4_sb_release(struct kobject *kobj)
2254 {
2255         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2256                                                 s_kobj);
2257         complete(&sbi->s_kobj_unregister);
2258 }
2259
2260
2261 static struct sysfs_ops ext4_attr_ops = {
2262         .show   = ext4_attr_show,
2263         .store  = ext4_attr_store,
2264 };
2265
2266 static struct kobj_type ext4_ktype = {
2267         .default_attrs  = ext4_attrs,
2268         .sysfs_ops      = &ext4_attr_ops,
2269         .release        = ext4_sb_release,
2270 };
2271
2272 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
2273                                 __releases(kernel_lock)
2274                                 __acquires(kernel_lock)
2275 {
2276         struct buffer_head *bh;
2277         struct ext4_super_block *es = NULL;
2278         struct ext4_sb_info *sbi;
2279         ext4_fsblk_t block;
2280         ext4_fsblk_t sb_block = get_sb_block(&data);
2281         ext4_fsblk_t logical_sb_block;
2282         unsigned long offset = 0;
2283         unsigned long journal_devnum = 0;
2284         unsigned long def_mount_opts;
2285         struct inode *root;
2286         char *cp;
2287         const char *descr;
2288         int ret = -EINVAL;
2289         int blocksize;
2290         unsigned int db_count;
2291         unsigned int i;
2292         int needs_recovery, has_huge_files;
2293         int features;
2294         __u64 blocks_count;
2295         int err;
2296         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2297
2298         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2299         if (!sbi)
2300                 return -ENOMEM;
2301
2302         sbi->s_blockgroup_lock =
2303                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
2304         if (!sbi->s_blockgroup_lock) {
2305                 kfree(sbi);
2306                 return -ENOMEM;
2307         }
2308         sb->s_fs_info = sbi;
2309         sbi->s_mount_opt = 0;
2310         sbi->s_resuid = EXT4_DEF_RESUID;
2311         sbi->s_resgid = EXT4_DEF_RESGID;
2312         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
2313         sbi->s_sb_block = sb_block;
2314         sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part,
2315                                                       sectors[1]);
2316
2317         unlock_kernel();
2318
2319         /* Cleanup superblock name */
2320         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
2321                 *cp = '!';
2322
2323         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
2324         if (!blocksize) {
2325                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
2326                 goto out_fail;
2327         }
2328
2329         /*
2330          * The ext4 superblock will not be buffer aligned for other than 1kB
2331          * block sizes.  We need to calculate the offset from buffer start.
2332          */
2333         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
2334                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2335                 offset = do_div(logical_sb_block, blocksize);
2336         } else {
2337                 logical_sb_block = sb_block;
2338         }
2339
2340         if (!(bh = sb_bread(sb, logical_sb_block))) {
2341                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
2342                 goto out_fail;
2343         }
2344         /*
2345          * Note: s_es must be initialized as soon as possible because
2346          *       some ext4 macro-instructions depend on its value
2347          */
2348         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2349         sbi->s_es = es;
2350         sb->s_magic = le16_to_cpu(es->s_magic);
2351         if (sb->s_magic != EXT4_SUPER_MAGIC)
2352                 goto cantfind_ext4;
2353         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
2354
2355         /* Set defaults before we parse the mount options */
2356         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
2357         if (def_mount_opts & EXT4_DEFM_DEBUG)
2358                 set_opt(sbi->s_mount_opt, DEBUG);
2359         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
2360                 set_opt(sbi->s_mount_opt, GRPID);
2361         if (def_mount_opts & EXT4_DEFM_UID16)
2362                 set_opt(sbi->s_mount_opt, NO_UID32);
2363 #ifdef CONFIG_EXT4_FS_XATTR
2364         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
2365                 set_opt(sbi->s_mount_opt, XATTR_USER);
2366 #endif
2367 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2368         if (def_mount_opts & EXT4_DEFM_ACL)
2369                 set_opt(sbi->s_mount_opt, POSIX_ACL);
2370 #endif
2371         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
2372                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
2373         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
2374                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
2375         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
2376                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
2377
2378         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
2379                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
2380         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
2381                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
2382         else
2383                 set_opt(sbi->s_mount_opt, ERRORS_RO);
2384
2385         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
2386         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
2387         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
2388         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
2389         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
2390         sbi->s_mb_history_max = default_mb_history_length;
2391
2392         set_opt(sbi->s_mount_opt, BARRIER);
2393
2394         /*
2395          * enable delayed allocation by default
2396          * Use -o nodelalloc to turn it off
2397          */
2398         set_opt(sbi->s_mount_opt, DELALLOC);
2399
2400         if (!parse_options((char *) data, sb, &journal_devnum,
2401                            &journal_ioprio, NULL, 0))
2402                 goto failed_mount;
2403
2404         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2405                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2406
2407         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
2408             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
2409              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
2410              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
2411                 ext4_msg(sb, KERN_WARNING,
2412                        "feature flags set on rev 0 fs, "
2413                        "running e2fsck is recommended");
2414
2415         /*
2416          * Check feature flags regardless of the revision level, since we
2417          * previously didn't change the revision level when setting the flags,
2418          * so there is a chance incompat flags are set on a rev 0 filesystem.
2419          */
2420         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
2421         if (features) {
2422                 ext4_msg(sb, KERN_ERR,
2423                         "Couldn't mount because of "
2424                         "unsupported optional features (%x)",
2425                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2426                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2427                 goto failed_mount;
2428         }
2429         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
2430         if (!(sb->s_flags & MS_RDONLY) && features) {
2431                 ext4_msg(sb, KERN_ERR,
2432                         "Couldn't mount RDWR because of "
2433                         "unsupported optional features (%x)",
2434                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2435                         ~EXT4_FEATURE_RO_COMPAT_SUPP));
2436                 goto failed_mount;
2437         }
2438         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2439                                     EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
2440         if (has_huge_files) {
2441                 /*
2442                  * Large file size enabled file system can only be
2443                  * mount if kernel is build with CONFIG_LBDAF
2444                  */
2445                 if (sizeof(root->i_blocks) < sizeof(u64) &&
2446                                 !(sb->s_flags & MS_RDONLY)) {
2447                         ext4_msg(sb, KERN_ERR, "Filesystem with huge "
2448                                         "files cannot be mounted read-write "
2449                                         "without CONFIG_LBDAF");
2450                         goto failed_mount;
2451                 }
2452         }
2453         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2454
2455         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2456             blocksize > EXT4_MAX_BLOCK_SIZE) {
2457                 ext4_msg(sb, KERN_ERR,
2458                        "Unsupported filesystem blocksize %d", blocksize);
2459                 goto failed_mount;
2460         }
2461
2462         if (sb->s_blocksize != blocksize) {
2463                 /* Validate the filesystem blocksize */
2464                 if (!sb_set_blocksize(sb, blocksize)) {
2465                         ext4_msg(sb, KERN_ERR, "bad block size %d",
2466                                         blocksize);
2467                         goto failed_mount;
2468                 }
2469
2470                 brelse(bh);
2471                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2472                 offset = do_div(logical_sb_block, blocksize);
2473                 bh = sb_bread(sb, logical_sb_block);
2474                 if (!bh) {
2475                         ext4_msg(sb, KERN_ERR,
2476                                "Can't read superblock on 2nd try");
2477                         goto failed_mount;
2478                 }
2479                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2480                 sbi->s_es = es;
2481                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2482                         ext4_msg(sb, KERN_ERR,
2483                                "Magic mismatch, very weird!");
2484                         goto failed_mount;
2485                 }
2486         }
2487
2488         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
2489                                                       has_huge_files);
2490         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
2491
2492         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2493                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2494                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2495         } else {
2496                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2497                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2498                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2499                     (!is_power_of_2(sbi->s_inode_size)) ||
2500                     (sbi->s_inode_size > blocksize)) {
2501                         ext4_msg(sb, KERN_ERR,
2502                                "unsupported inode size: %d",
2503                                sbi->s_inode_size);
2504                         goto failed_mount;
2505                 }
2506                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2507                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2508         }
2509
2510         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2511         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2512                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2513                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2514                     !is_power_of_2(sbi->s_desc_size)) {
2515                         ext4_msg(sb, KERN_ERR,
2516                                "unsupported descriptor size %lu",
2517                                sbi->s_desc_size);
2518                         goto failed_mount;
2519                 }
2520         } else
2521                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2522
2523         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2524         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2525         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2526                 goto cantfind_ext4;
2527
2528         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2529         if (sbi->s_inodes_per_block == 0)
2530                 goto cantfind_ext4;
2531         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2532                                         sbi->s_inodes_per_block;
2533         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2534         sbi->s_sbh = bh;
2535         sbi->s_mount_state = le16_to_cpu(es->s_state);
2536         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2537         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2538
2539         for (i = 0; i < 4; i++)
2540                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2541         sbi->s_def_hash_version = es->s_def_hash_version;
2542         i = le32_to_cpu(es->s_flags);
2543         if (i & EXT2_FLAGS_UNSIGNED_HASH)
2544                 sbi->s_hash_unsigned = 3;
2545         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
2546 #ifdef __CHAR_UNSIGNED__
2547                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
2548                 sbi->s_hash_unsigned = 3;
2549 #else
2550                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
2551 #endif
2552                 sb->s_dirt = 1;
2553         }
2554
2555         if (sbi->s_blocks_per_group > blocksize * 8) {
2556                 ext4_msg(sb, KERN_ERR,
2557                        "#blocks per group too big: %lu",
2558                        sbi->s_blocks_per_group);
2559                 goto failed_mount;
2560         }
2561         if (sbi->s_inodes_per_group > blocksize * 8) {
2562                 ext4_msg(sb, KERN_ERR,
2563                        "#inodes per group too big: %lu",
2564                        sbi->s_inodes_per_group);
2565                 goto failed_mount;
2566         }
2567
2568         if (ext4_blocks_count(es) >
2569                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2570                 ext4_msg(sb, KERN_ERR, "filesystem"
2571                         " too large to mount safely");
2572                 if (sizeof(sector_t) < 8)
2573                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
2574                 goto failed_mount;
2575         }
2576
2577         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2578                 goto cantfind_ext4;
2579
2580         /* check blocks count against device size */
2581         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
2582         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
2583                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
2584                        "exceeds size of device (%llu blocks)",
2585                        ext4_blocks_count(es), blocks_count);
2586                 goto failed_mount;
2587         }
2588
2589         /*
2590          * It makes no sense for the first data block to be beyond the end
2591          * of the filesystem.
2592          */
2593         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
2594                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
2595                          "block %u is beyond end of filesystem (%llu)",
2596                          le32_to_cpu(es->s_first_data_block),
2597                          ext4_blocks_count(es));
2598                 goto failed_mount;
2599         }
2600         blocks_count = (ext4_blocks_count(es) -
2601                         le32_to_cpu(es->s_first_data_block) +
2602                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2603         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2604         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
2605                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
2606                        "(block count %llu, first data block %u, "
2607                        "blocks per group %lu)", sbi->s_groups_count,
2608                        ext4_blocks_count(es),
2609                        le32_to_cpu(es->s_first_data_block),
2610                        EXT4_BLOCKS_PER_GROUP(sb));
2611                 goto failed_mount;
2612         }
2613         sbi->s_groups_count = blocks_count;
2614         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2615                    EXT4_DESC_PER_BLOCK(sb);
2616         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2617                                     GFP_KERNEL);
2618         if (sbi->s_group_desc == NULL) {
2619                 ext4_msg(sb, KERN_ERR, "not enough memory");
2620                 goto failed_mount;
2621         }
2622
2623 #ifdef CONFIG_PROC_FS
2624         if (ext4_proc_root)
2625                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
2626 #endif
2627
2628         bgl_lock_init(sbi->s_blockgroup_lock);
2629
2630         for (i = 0; i < db_count; i++) {
2631                 block = descriptor_loc(sb, logical_sb_block, i);
2632                 sbi->s_group_desc[i] = sb_bread(sb, block);
2633                 if (!sbi->s_group_desc[i]) {
2634                         ext4_msg(sb, KERN_ERR,
2635                                "can't read group descriptor %d", i);
2636                         db_count = i;
2637                         goto failed_mount2;
2638                 }
2639         }
2640         if (!ext4_check_descriptors(sb)) {
2641                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
2642                 goto failed_mount2;
2643         }
2644         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2645                 if (!ext4_fill_flex_info(sb)) {
2646                         ext4_msg(sb, KERN_ERR,
2647                                "unable to initialize "
2648                                "flex_bg meta info!");
2649                         goto failed_mount2;
2650                 }
2651
2652         sbi->s_gdb_count = db_count;
2653         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2654         spin_lock_init(&sbi->s_next_gen_lock);
2655
2656         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2657                         ext4_count_free_blocks(sb));
2658         if (!err) {
2659                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2660                                 ext4_count_free_inodes(sb));
2661         }
2662         if (!err) {
2663                 err = percpu_counter_init(&sbi->s_dirs_counter,
2664                                 ext4_count_dirs(sb));
2665         }
2666         if (!err) {
2667                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
2668         }
2669         if (err) {
2670                 ext4_msg(sb, KERN_ERR, "insufficient memory");
2671                 goto failed_mount3;
2672         }
2673
2674         sbi->s_stripe = ext4_get_stripe_size(sbi);
2675
2676         /*
2677          * set up enough so that it can read an inode
2678          */
2679         if (!test_opt(sb, NOLOAD) &&
2680             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
2681                 sb->s_op = &ext4_sops;
2682         else
2683                 sb->s_op = &ext4_nojournal_sops;
2684         sb->s_export_op = &ext4_export_ops;
2685         sb->s_xattr = ext4_xattr_handlers;
2686 #ifdef CONFIG_QUOTA
2687         sb->s_qcop = &ext4_qctl_operations;
2688         sb->dq_op = &ext4_quota_operations;
2689 #endif
2690         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2691         mutex_init(&sbi->s_orphan_lock);
2692         mutex_init(&sbi->s_resize_lock);
2693
2694         sb->s_root = NULL;
2695
2696         needs_recovery = (es->s_last_orphan != 0 ||
2697                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2698                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2699
2700         /*
2701          * The first inode we look at is the journal inode.  Don't try
2702          * root first: it may be modified in the journal!
2703          */
2704         if (!test_opt(sb, NOLOAD) &&
2705             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2706                 if (ext4_load_journal(sb, es, journal_devnum))
2707                         goto failed_mount3;
2708                 if (!(sb->s_flags & MS_RDONLY) &&
2709                     EXT4_SB(sb)->s_journal->j_failed_commit) {
2710                         ext4_msg(sb, KERN_CRIT, "error: "
2711                                "ext4_fill_super: Journal transaction "
2712                                "%u is corrupt",
2713                                EXT4_SB(sb)->s_journal->j_failed_commit);
2714                         if (test_opt(sb, ERRORS_RO)) {
2715                                 ext4_msg(sb, KERN_CRIT,
2716                                        "Mounting filesystem read-only");
2717                                 sb->s_flags |= MS_RDONLY;
2718                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2719                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2720                         }
2721                         if (test_opt(sb, ERRORS_PANIC)) {
2722                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2723                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2724                                 ext4_commit_super(sb, 1);
2725                                 goto failed_mount4;
2726                         }
2727                 }
2728         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
2729               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2730                 ext4_msg(sb, KERN_ERR, "required journal recovery "
2731                        "suppressed and not mounted read-only");
2732                 goto failed_mount4;
2733         } else {
2734                 clear_opt(sbi->s_mount_opt, DATA_FLAGS);
2735                 set_opt(sbi->s_mount_opt, WRITEBACK_DATA);
2736                 sbi->s_journal = NULL;
2737                 needs_recovery = 0;
2738                 goto no_journal;
2739         }
2740
2741         if (ext4_blocks_count(es) > 0xffffffffULL &&
2742             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2743                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2744                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
2745                 goto failed_mount4;
2746         }
2747
2748         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2749                 jbd2_journal_set_features(sbi->s_journal,
2750                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2751                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2752         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2753                 jbd2_journal_set_features(sbi->s_journal,
2754                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2755                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2756                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2757         } else {
2758                 jbd2_journal_clear_features(sbi->s_journal,
2759                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2760                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2761         }
2762
2763         /* We have now updated the journal if required, so we can
2764          * validate the data journaling mode. */
2765         switch (test_opt(sb, DATA_FLAGS)) {
2766         case 0:
2767                 /* No mode set, assume a default based on the journal
2768                  * capabilities: ORDERED_DATA if the journal can
2769                  * cope, else JOURNAL_DATA
2770                  */
2771                 if (jbd2_journal_check_available_features
2772                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2773                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2774                 else
2775                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2776                 break;
2777
2778         case EXT4_MOUNT_ORDERED_DATA:
2779         case EXT4_MOUNT_WRITEBACK_DATA:
2780                 if (!jbd2_journal_check_available_features
2781                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2782                         ext4_msg(sb, KERN_ERR, "Journal does not support "
2783                                "requested data journaling mode");
2784                         goto failed_mount4;
2785                 }
2786         default:
2787                 break;
2788         }
2789         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
2790
2791 no_journal:
2792
2793         if (test_opt(sb, NOBH)) {
2794                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2795                         ext4_msg(sb, KERN_WARNING, "Ignoring nobh option - "
2796                                 "its supported only with writeback mode");
2797                         clear_opt(sbi->s_mount_opt, NOBH);
2798                 }
2799         }
2800         /*
2801          * The jbd2_journal_load will have done any necessary log recovery,
2802          * so we can safely mount the rest of the filesystem now.
2803          */
2804
2805         root = ext4_iget(sb, EXT4_ROOT_INO);
2806         if (IS_ERR(root)) {
2807                 ext4_msg(sb, KERN_ERR, "get root inode failed");
2808                 ret = PTR_ERR(root);
2809                 goto failed_mount4;
2810         }
2811         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2812                 iput(root);
2813                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
2814                 goto failed_mount4;
2815         }
2816         sb->s_root = d_alloc_root(root);
2817         if (!sb->s_root) {
2818                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
2819                 iput(root);
2820                 ret = -ENOMEM;
2821                 goto failed_mount4;
2822         }
2823
2824         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
2825
2826         /* determine the minimum size of new large inodes, if present */
2827         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2828                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2829                                                      EXT4_GOOD_OLD_INODE_SIZE;
2830                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2831                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2832                         if (sbi->s_want_extra_isize <
2833                             le16_to_cpu(es->s_want_extra_isize))
2834                                 sbi->s_want_extra_isize =
2835                                         le16_to_cpu(es->s_want_extra_isize);
2836                         if (sbi->s_want_extra_isize <
2837                             le16_to_cpu(es->s_min_extra_isize))
2838                                 sbi->s_want_extra_isize =
2839                                         le16_to_cpu(es->s_min_extra_isize);
2840                 }
2841         }
2842         /* Check if enough inode space is available */
2843         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2844                                                         sbi->s_inode_size) {
2845                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2846                                                        EXT4_GOOD_OLD_INODE_SIZE;
2847                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
2848                          "available");
2849         }
2850
2851         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
2852                 ext4_msg(sb, KERN_WARNING, "Ignoring delalloc option - "
2853                          "requested data journaling mode");
2854                 clear_opt(sbi->s_mount_opt, DELALLOC);
2855         } else if (test_opt(sb, DELALLOC))
2856                 ext4_msg(sb, KERN_INFO, "delayed allocation enabled");
2857
2858         err = ext4_setup_system_zone(sb);
2859         if (err) {
2860                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
2861                          "zone (%d)\n", err);
2862                 goto failed_mount4;
2863         }
2864
2865         ext4_ext_init(sb);
2866         err = ext4_mb_init(sb, needs_recovery);
2867         if (err) {
2868                 ext4_msg(sb, KERN_ERR, "failed to initalize mballoc (%d)",
2869                          err);
2870                 goto failed_mount4;
2871         }
2872
2873         sbi->s_kobj.kset = ext4_kset;
2874         init_completion(&sbi->s_kobj_unregister);
2875         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
2876                                    "%s", sb->s_id);
2877         if (err) {
2878                 ext4_mb_release(sb);
2879                 ext4_ext_release(sb);
2880                 goto failed_mount4;
2881         };
2882
2883         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2884         ext4_orphan_cleanup(sb, es);
2885         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2886         if (needs_recovery) {
2887                 ext4_msg(sb, KERN_INFO, "recovery complete");
2888                 ext4_mark_recovery_complete(sb, es);
2889         }
2890         if (EXT4_SB(sb)->s_journal) {
2891                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2892                         descr = " journalled data mode";
2893                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2894                         descr = " ordered data mode";
2895                 else
2896                         descr = " writeback data mode";
2897         } else
2898                 descr = "out journal";
2899
2900         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s", descr);
2901
2902         lock_kernel();
2903         return 0;
2904
2905 cantfind_ext4:
2906         if (!silent)
2907                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
2908         goto failed_mount;
2909
2910 failed_mount4:
2911         ext4_msg(sb, KERN_ERR, "mount failed");
2912         ext4_release_system_zone(sb);
2913         if (sbi->s_journal) {
2914                 jbd2_journal_destroy(sbi->s_journal);
2915                 sbi->s_journal = NULL;
2916         }
2917 failed_mount3:
2918         if (sbi->s_flex_groups) {
2919                 if (is_vmalloc_addr(sbi->s_flex_groups))
2920                         vfree(sbi->s_flex_groups);
2921                 else
2922                         kfree(sbi->s_flex_groups);
2923         }
2924         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2925         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2926         percpu_counter_destroy(&sbi->s_dirs_counter);
2927         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
2928 failed_mount2:
2929         for (i = 0; i < db_count; i++)
2930                 brelse(sbi->s_group_desc[i]);
2931         kfree(sbi->s_group_desc);
2932 failed_mount:
2933         if (sbi->s_proc) {
2934                 remove_proc_entry(sb->s_id, ext4_proc_root);
2935         }
2936 #ifdef CONFIG_QUOTA
2937         for (i = 0; i < MAXQUOTAS; i++)
2938                 kfree(sbi->s_qf_names[i]);
2939 #endif
2940         ext4_blkdev_remove(sbi);
2941         brelse(bh);
2942 out_fail:
2943         sb->s_fs_info = NULL;
2944         kfree(sbi->s_blockgroup_lock);
2945         kfree(sbi);
2946         lock_kernel();
2947         return ret;
2948 }
2949
2950 /*
2951  * Setup any per-fs journal parameters now.  We'll do this both on
2952  * initial mount, once the journal has been initialised but before we've
2953  * done any recovery; and again on any subsequent remount.
2954  */
2955 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2956 {
2957         struct ext4_sb_info *sbi = EXT4_SB(sb);
2958
2959         journal->j_commit_interval = sbi->s_commit_interval;
2960         journal->j_min_batch_time = sbi->s_min_batch_time;
2961         journal->j_max_batch_time = sbi->s_max_batch_time;
2962
2963         spin_lock(&journal->j_state_lock);
2964         if (test_opt(sb, BARRIER))
2965                 journal->j_flags |= JBD2_BARRIER;
2966         else
2967                 journal->j_flags &= ~JBD2_BARRIER;
2968         if (test_opt(sb, DATA_ERR_ABORT))
2969                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
2970         else
2971                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
2972         spin_unlock(&journal->j_state_lock);
2973 }
2974
2975 static journal_t *ext4_get_journal(struct super_block *sb,
2976                                    unsigned int journal_inum)
2977 {
2978         struct inode *journal_inode;
2979         journal_t *journal;
2980
2981         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2982
2983         /* First, test for the existence of a valid inode on disk.  Bad
2984          * things happen if we iget() an unused inode, as the subsequent
2985          * iput() will try to delete it. */
2986
2987         journal_inode = ext4_iget(sb, journal_inum);
2988         if (IS_ERR(journal_inode)) {
2989                 ext4_msg(sb, KERN_ERR, "no journal found");
2990                 return NULL;
2991         }
2992         if (!journal_inode->i_nlink) {
2993                 make_bad_inode(journal_inode);
2994                 iput(journal_inode);
2995                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
2996                 return NULL;
2997         }
2998
2999         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3000                   journal_inode, journal_inode->i_size);
3001         if (!S_ISREG(journal_inode->i_mode)) {
3002                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
3003                 iput(journal_inode);
3004                 return NULL;
3005         }
3006
3007         journal = jbd2_journal_init_inode(journal_inode);
3008         if (!journal) {
3009                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3010                 iput(journal_inode);
3011                 return NULL;
3012         }
3013         journal->j_private = sb;
3014         ext4_init_journal_params(sb, journal);
3015         return journal;
3016 }
3017
3018 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3019                                        dev_t j_dev)
3020 {
3021         struct buffer_head *bh;
3022         journal_t *journal;
3023         ext4_fsblk_t start;
3024         ext4_fsblk_t len;
3025         int hblock, blocksize;
3026         ext4_fsblk_t sb_block;
3027         unsigned long offset;
3028         struct ext4_super_block *es;
3029         struct block_device *bdev;
3030
3031         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3032
3033         bdev = ext4_blkdev_get(j_dev, sb);
3034         if (bdev == NULL)
3035                 return NULL;
3036
3037         if (bd_claim(bdev, sb)) {
3038                 ext4_msg(sb, KERN_ERR,
3039                         "failed to claim external journal device");
3040                 blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
3041                 return NULL;
3042         }
3043
3044         blocksize = sb->s_blocksize;
3045         hblock = bdev_logical_block_size(bdev);
3046         if (blocksize < hblock) {
3047                 ext4_msg(sb, KERN_ERR,
3048                         "blocksize too small for journal device");
3049                 goto out_bdev;
3050         }
3051
3052         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3053         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3054         set_blocksize(bdev, blocksize);
3055         if (!(bh = __bread(bdev, sb_block, blocksize))) {
3056                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3057                        "external journal");
3058                 goto out_bdev;
3059         }
3060
3061         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3062         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3063             !(le32_to_cpu(es->s_feature_incompat) &
3064               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3065                 ext4_msg(sb, KERN_ERR, "external journal has "
3066                                         "bad superblock");
3067                 brelse(bh);
3068                 goto out_bdev;
3069         }
3070
3071         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3072                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3073                 brelse(bh);
3074                 goto out_bdev;
3075         }
3076
3077         len = ext4_blocks_count(es);
3078         start = sb_block + 1;
3079         brelse(bh);     /* we're done with the superblock */
3080
3081         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3082                                         start, len, blocksize);
3083         if (!journal) {
3084                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
3085                 goto out_bdev;
3086         }
3087         journal->j_private = sb;
3088         ll_rw_block(READ, 1, &journal->j_sb_buffer);
3089         wait_on_buffer(journal->j_sb_buffer);
3090         if (!buffer_uptodate(journal->j_sb_buffer)) {
3091                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3092                 goto out_journal;
3093         }
3094         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3095                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
3096                                         "user (unsupported) - %d",
3097                         be32_to_cpu(journal->j_superblock->s_nr_users));
3098                 goto out_journal;
3099         }
3100         EXT4_SB(sb)->journal_bdev = bdev;
3101         ext4_init_journal_params(sb, journal);
3102         return journal;
3103
3104 out_journal:
3105         jbd2_journal_destroy(journal);
3106 out_bdev:
3107         ext4_blkdev_put(bdev);
3108         return NULL;
3109 }
3110
3111 static int ext4_load_journal(struct super_block *sb,
3112                              struct ext4_super_block *es,
3113                              unsigned long journal_devnum)
3114 {
3115         journal_t *journal;
3116         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3117         dev_t journal_dev;
3118         int err = 0;
3119         int really_read_only;
3120
3121         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3122
3123         if (journal_devnum &&
3124             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3125                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3126                         "numbers have changed");
3127                 journal_dev = new_decode_dev(journal_devnum);
3128         } else
3129                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3130
3131         really_read_only = bdev_read_only(sb->s_bdev);
3132
3133         /*
3134          * Are we loading a blank journal or performing recovery after a
3135          * crash?  For recovery, we need to check in advance whether we
3136          * can get read-write access to the device.
3137          */
3138         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3139                 if (sb->s_flags & MS_RDONLY) {
3140                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
3141                                         "required on readonly filesystem");
3142                         if (really_read_only) {
3143                                 ext4_msg(sb, KERN_ERR, "write access "
3144                                         "unavailable, cannot proceed");
3145                                 return -EROFS;
3146                         }
3147                         ext4_msg(sb, KERN_INFO, "write access will "
3148                                "be enabled during recovery");
3149                 }
3150         }
3151
3152         if (journal_inum && journal_dev) {
3153                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3154                        "and inode journals!");
3155                 return -EINVAL;
3156         }
3157
3158         if (journal_inum) {
3159                 if (!(journal = ext4_get_journal(sb, journal_inum)))
3160                         return -EINVAL;
3161         } else {
3162                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3163                         return -EINVAL;
3164         }
3165
3166         if (journal->j_flags & JBD2_BARRIER)
3167                 ext4_msg(sb, KERN_INFO, "barriers enabled");
3168         else
3169                 ext4_msg(sb, KERN_INFO, "barriers disabled");
3170
3171         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
3172                 err = jbd2_journal_update_format(journal);
3173                 if (err)  {
3174                         ext4_msg(sb, KERN_ERR, "error updating journal");
3175                         jbd2_journal_destroy(journal);
3176                         return err;
3177                 }
3178         }
3179
3180         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3181                 err = jbd2_journal_wipe(journal, !really_read_only);
3182         if (!err)
3183                 err = jbd2_journal_load(journal);
3184
3185         if (err) {
3186                 ext4_msg(sb, KERN_ERR, "error loading journal");
3187                 jbd2_journal_destroy(journal);
3188                 return err;
3189         }
3190
3191         EXT4_SB(sb)->s_journal = journal;
3192         ext4_clear_journal_err(sb, es);
3193
3194         if (journal_devnum &&
3195             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3196                 es->s_journal_dev = cpu_to_le32(journal_devnum);
3197
3198                 /* Make sure we flush the recovery flag to disk. */
3199                 ext4_commit_super(sb, 1);
3200         }
3201
3202         return 0;
3203 }
3204
3205 static int ext4_commit_super(struct super_block *sb, int sync)
3206 {
3207         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
3208         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3209         int error = 0;
3210
3211         if (!sbh)
3212                 return error;
3213         if (buffer_write_io_error(sbh)) {
3214                 /*
3215                  * Oh, dear.  A previous attempt to write the
3216                  * superblock failed.  This could happen because the
3217                  * USB device was yanked out.  Or it could happen to
3218                  * be a transient write error and maybe the block will
3219                  * be remapped.  Nothing we can do but to retry the
3220                  * write and hope for the best.
3221                  */
3222                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
3223                        "superblock detected");
3224                 clear_buffer_write_io_error(sbh);
3225                 set_buffer_uptodate(sbh);
3226         }
3227         es->s_wtime = cpu_to_le32(get_seconds());
3228         es->s_kbytes_written =
3229                 cpu_to_le64(EXT4_SB(sb)->s_kbytes_written + 
3230                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
3231                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
3232         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
3233                                         &EXT4_SB(sb)->s_freeblocks_counter));
3234         es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(
3235                                         &EXT4_SB(sb)->s_freeinodes_counter));
3236         sb->s_dirt = 0;
3237         BUFFER_TRACE(sbh, "marking dirty");
3238         mark_buffer_dirty(sbh);
3239         if (sync) {
3240                 error = sync_dirty_buffer(sbh);
3241                 if (error)
3242                         return error;
3243
3244                 error = buffer_write_io_error(sbh);
3245                 if (error) {
3246                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
3247                                "superblock");
3248                         clear_buffer_write_io_error(sbh);
3249                         set_buffer_uptodate(sbh);
3250                 }
3251         }
3252         return error;
3253 }
3254
3255 /*
3256  * Have we just finished recovery?  If so, and if we are mounting (or
3257  * remounting) the filesystem readonly, then we will end up with a
3258  * consistent fs on disk.  Record that fact.
3259  */
3260 static void ext4_mark_recovery_complete(struct super_block *sb,
3261                                         struct ext4_super_block *es)
3262 {
3263         journal_t *journal = EXT4_SB(sb)->s_journal;
3264
3265         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3266                 BUG_ON(journal != NULL);
3267                 return;
3268         }
3269         jbd2_journal_lock_updates(journal);
3270         if (jbd2_journal_flush(journal) < 0)
3271                 goto out;
3272
3273         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
3274             sb->s_flags & MS_RDONLY) {
3275                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3276                 ext4_commit_super(sb, 1);
3277         }
3278
3279 out:
3280         jbd2_journal_unlock_updates(journal);
3281 }
3282
3283 /*
3284  * If we are mounting (or read-write remounting) a filesystem whose journal
3285  * has recorded an error from a previous lifetime, move that error to the
3286  * main filesystem now.
3287  */
3288 static void ext4_clear_journal_err(struct super_block *sb,
3289                                    struct ext4_super_block *es)
3290 {
3291         journal_t *journal;
3292         int j_errno;
3293         const char *errstr;
3294
3295         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3296
3297         journal = EXT4_SB(sb)->s_journal;
3298
3299         /*
3300          * Now check for any error status which may have been recorded in the
3301          * journal by a prior ext4_error() or ext4_abort()
3302          */
3303
3304         j_errno = jbd2_journal_errno(journal);
3305         if (j_errno) {
3306                 char nbuf[16];
3307
3308                 errstr = ext4_decode_error(sb, j_errno, nbuf);
3309                 ext4_warning(sb, __func__, "Filesystem error recorded "
3310                              "from previous mount: %s", errstr);
3311                 ext4_warning(sb, __func__, "Marking fs in need of "
3312                              "filesystem check.");
3313
3314                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
3315                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
3316                 ext4_commit_super(sb, 1);
3317
3318                 jbd2_journal_clear_err(journal);
3319         }
3320 }
3321
3322 /*
3323  * Force the running and committing transactions to commit,
3324  * and wait on the commit.
3325  */
3326 int ext4_force_commit(struct super_block *sb)
3327 {
3328         journal_t *journal;
3329         int ret = 0;
3330
3331         if (sb->s_flags & MS_RDONLY)
3332                 return 0;
3333
3334         journal = EXT4_SB(sb)->s_journal;
3335         if (journal)
3336                 ret = ext4_journal_force_commit(journal);
3337
3338         return ret;
3339 }
3340
3341 static void ext4_write_super(struct super_block *sb)
3342 {
3343         lock_super(sb);
3344         ext4_commit_super(sb, 1);
3345         unlock_super(sb);
3346 }
3347
3348 static int ext4_sync_fs(struct super_block *sb, int wait)
3349 {
3350         int ret = 0;
3351         tid_t target;
3352
3353         trace_ext4_sync_fs(sb, wait);
3354         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
3355                 if (wait)
3356                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
3357         }
3358         return ret;
3359 }
3360
3361 /*
3362  * LVM calls this function before a (read-only) snapshot is created.  This
3363  * gives us a chance to flush the journal completely and mark the fs clean.
3364  */
3365 static int ext4_freeze(struct super_block *sb)
3366 {
3367         int error = 0;
3368         journal_t *journal;
3369
3370         if (sb->s_flags & MS_RDONLY)
3371                 return 0;
3372
3373         journal = EXT4_SB(sb)->s_journal;
3374
3375         /* Now we set up the journal barrier. */
3376         jbd2_journal_lock_updates(journal);
3377
3378         /*
3379          * Don't clear the needs_recovery flag if we failed to flush
3380          * the journal.
3381          */
3382         error = jbd2_journal_flush(journal);
3383         if (error < 0) {
3384         out:
3385                 jbd2_journal_unlock_updates(journal);
3386                 return error;
3387         }
3388
3389         /* Journal blocked and flushed, clear needs_recovery flag. */
3390         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3391         error = ext4_commit_super(sb, 1);
3392         if (error)
3393                 goto out;
3394         return 0;
3395 }
3396
3397 /*
3398  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
3399  * flag here, even though the filesystem is not technically dirty yet.
3400  */
3401 static int ext4_unfreeze(struct super_block *sb)
3402 {
3403         if (sb->s_flags & MS_RDONLY)
3404                 return 0;
3405
3406         lock_super(sb);
3407         /* Reset the needs_recovery flag before the fs is unlocked. */
3408         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3409         ext4_commit_super(sb, 1);
3410         unlock_super(sb);
3411         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3412         return 0;
3413 }
3414
3415 static int ext4_remount(struct super_block *sb, int *flags, char *data)
3416 {
3417         struct ext4_super_block *es;
3418         struct ext4_sb_info *sbi = EXT4_SB(sb);
3419         ext4_fsblk_t n_blocks_count = 0;
3420         unsigned long old_sb_flags;
3421         struct ext4_mount_options old_opts;
3422         ext4_group_t g;
3423         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3424         int err;
3425 #ifdef CONFIG_QUOTA
3426         int i;
3427 #endif
3428
3429         lock_kernel();
3430
3431         /* Store the original options */
3432         lock_super(sb);
3433         old_sb_flags = sb->s_flags;
3434         old_opts.s_mount_opt = sbi->s_mount_opt;
3435         old_opts.s_resuid = sbi->s_resuid;
3436         old_opts.s_resgid = sbi->s_resgid;
3437         old_opts.s_commit_interval = sbi->s_commit_interval;
3438         old_opts.s_min_batch_time = sbi->s_min_batch_time;
3439         old_opts.s_max_batch_time = sbi->s_max_batch_time;
3440 #ifdef CONFIG_QUOTA
3441         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
3442         for (i = 0; i < MAXQUOTAS; i++)
3443                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
3444 #endif
3445         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
3446                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
3447
3448         /*
3449          * Allow the "check" option to be passed as a remount option.
3450          */
3451         if (!parse_options(data, sb, NULL, &journal_ioprio,
3452                            &n_blocks_count, 1)) {
3453                 err = -EINVAL;
3454                 goto restore_opts;
3455         }
3456
3457         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
3458                 ext4_abort(sb, __func__, "Abort forced by user");
3459
3460         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3461                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
3462
3463         es = sbi->s_es;
3464
3465         if (sbi->s_journal) {
3466                 ext4_init_journal_params(sb, sbi->s_journal);
3467                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3468         }
3469
3470         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
3471                 n_blocks_count > ext4_blocks_count(es)) {
3472                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
3473                         err = -EROFS;
3474                         goto restore_opts;
3475                 }
3476
3477                 if (*flags & MS_RDONLY) {
3478                         /*
3479                          * First of all, the unconditional stuff we have to do
3480                          * to disable replay of the journal when we next remount
3481                          */
3482                         sb->s_flags |= MS_RDONLY;
3483
3484                         /*
3485                          * OK, test if we are remounting a valid rw partition
3486                          * readonly, and if so set the rdonly flag and then
3487                          * mark the partition as valid again.
3488                          */
3489                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3490                             (sbi->s_mount_state & EXT4_VALID_FS))
3491                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
3492
3493                         if (sbi->s_journal)
3494                                 ext4_mark_recovery_complete(sb, es);
3495                 } else {
3496                         int ret;
3497                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3498                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
3499                                 ext4_msg(sb, KERN_WARNING, "couldn't "
3500                                        "remount RDWR because of unsupported "
3501                                        "optional features (%x)",
3502                                 (le32_to_cpu(sbi->s_es->s_feature_ro_compat) &
3503                                         ~EXT4_FEATURE_RO_COMPAT_SUPP));
3504                                 err = -EROFS;
3505                                 goto restore_opts;
3506                         }
3507
3508                         /*
3509                          * Make sure the group descriptor checksums
3510                          * are sane.  If they aren't, refuse to remount r/w.
3511                          */
3512                         for (g = 0; g < sbi->s_groups_count; g++) {
3513                                 struct ext4_group_desc *gdp =
3514                                         ext4_get_group_desc(sb, g, NULL);
3515
3516                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3517                                         ext4_msg(sb, KERN_ERR,
3518                "ext4_remount: Checksum for group %u failed (%u!=%u)",
3519                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3520                                                le16_to_cpu(gdp->bg_checksum));
3521                                         err = -EINVAL;
3522                                         goto restore_opts;
3523                                 }
3524                         }
3525
3526                         /*
3527                          * If we have an unprocessed orphan list hanging
3528                          * around from a previously readonly bdev mount,
3529                          * require a full umount/remount for now.
3530                          */
3531                         if (es->s_last_orphan) {
3532                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
3533                                        "remount RDWR because of unprocessed "
3534                                        "orphan inode list.  Please "
3535                                        "umount/remount instead");
3536                                 err = -EINVAL;
3537                                 goto restore_opts;
3538                         }
3539
3540                         /*
3541                          * Mounting a RDONLY partition read-write, so reread
3542                          * and store the current valid flag.  (It may have
3543                          * been changed by e2fsck since we originally mounted
3544                          * the partition.)
3545                          */
3546                         if (sbi->s_journal)
3547                                 ext4_clear_journal_err(sb, es);
3548                         sbi->s_mount_state = le16_to_cpu(es->s_state);
3549                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3550                                 goto restore_opts;
3551                         if (!ext4_setup_super(sb, es, 0))
3552                                 sb->s_flags &= ~MS_RDONLY;
3553                 }
3554         }
3555         ext4_setup_system_zone(sb);
3556         if (sbi->s_journal == NULL)
3557                 ext4_commit_super(sb, 1);
3558
3559 #ifdef CONFIG_QUOTA
3560         /* Release old quota file names */
3561         for (i = 0; i < MAXQUOTAS; i++)
3562                 if (old_opts.s_qf_names[i] &&
3563                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3564                         kfree(old_opts.s_qf_names[i]);
3565 #endif
3566         unlock_super(sb);
3567         unlock_kernel();
3568         return 0;
3569
3570 restore_opts:
3571         sb->s_flags = old_sb_flags;
3572         sbi->s_mount_opt = old_opts.s_mount_opt;