Push BKL down into ->remount_fs()
[linux-2.6.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/marker.h>
41 #include <linux/log2.h>
42 #include <linux/crc16.h>
43 #include <asm/uaccess.h>
44
45 #include "ext4.h"
46 #include "ext4_jbd2.h"
47 #include "xattr.h"
48 #include "acl.h"
49
50 static int default_mb_history_length = 1000;
51
52 module_param_named(default_mb_history_length, default_mb_history_length,
53                    int, 0644);
54 MODULE_PARM_DESC(default_mb_history_length,
55                  "Default number of entries saved for mb_history");
56
57 struct proc_dir_entry *ext4_proc_root;
58 static struct kset *ext4_kset;
59
60 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
61                              unsigned long journal_devnum);
62 static int ext4_commit_super(struct super_block *sb, int sync);
63 static void ext4_mark_recovery_complete(struct super_block *sb,
64                                         struct ext4_super_block *es);
65 static void ext4_clear_journal_err(struct super_block *sb,
66                                    struct ext4_super_block *es);
67 static int ext4_sync_fs(struct super_block *sb, int wait);
68 static const char *ext4_decode_error(struct super_block *sb, int errno,
69                                      char nbuf[16]);
70 static int ext4_remount(struct super_block *sb, int *flags, char *data);
71 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
72 static int ext4_unfreeze(struct super_block *sb);
73 static void ext4_write_super(struct super_block *sb);
74 static int ext4_freeze(struct super_block *sb);
75
76
77 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
78                                struct ext4_group_desc *bg)
79 {
80         return le32_to_cpu(bg->bg_block_bitmap_lo) |
81                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
82                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
83 }
84
85 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
86                                struct ext4_group_desc *bg)
87 {
88         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
89                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
90                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
91 }
92
93 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
94                               struct ext4_group_desc *bg)
95 {
96         return le32_to_cpu(bg->bg_inode_table_lo) |
97                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
98                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
99 }
100
101 __u32 ext4_free_blks_count(struct super_block *sb,
102                               struct ext4_group_desc *bg)
103 {
104         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
105                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
106                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
107 }
108
109 __u32 ext4_free_inodes_count(struct super_block *sb,
110                               struct ext4_group_desc *bg)
111 {
112         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
113                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
114                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
115 }
116
117 __u32 ext4_used_dirs_count(struct super_block *sb,
118                               struct ext4_group_desc *bg)
119 {
120         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
121                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
122                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
123 }
124
125 __u32 ext4_itable_unused_count(struct super_block *sb,
126                               struct ext4_group_desc *bg)
127 {
128         return le16_to_cpu(bg->bg_itable_unused_lo) |
129                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
130                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
131 }
132
133 void ext4_block_bitmap_set(struct super_block *sb,
134                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
135 {
136         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
137         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
138                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
139 }
140
141 void ext4_inode_bitmap_set(struct super_block *sb,
142                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
143 {
144         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
145         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
146                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
147 }
148
149 void ext4_inode_table_set(struct super_block *sb,
150                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
151 {
152         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
153         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
154                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
155 }
156
157 void ext4_free_blks_set(struct super_block *sb,
158                           struct ext4_group_desc *bg, __u32 count)
159 {
160         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
161         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
162                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
163 }
164
165 void ext4_free_inodes_set(struct super_block *sb,
166                           struct ext4_group_desc *bg, __u32 count)
167 {
168         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
169         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
170                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
171 }
172
173 void ext4_used_dirs_set(struct super_block *sb,
174                           struct ext4_group_desc *bg, __u32 count)
175 {
176         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
177         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
178                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
179 }
180
181 void ext4_itable_unused_set(struct super_block *sb,
182                           struct ext4_group_desc *bg, __u32 count)
183 {
184         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
185         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
186                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
187 }
188
189 /*
190  * Wrappers for jbd2_journal_start/end.
191  *
192  * The only special thing we need to do here is to make sure that all
193  * journal_end calls result in the superblock being marked dirty, so
194  * that sync() will call the filesystem's write_super callback if
195  * appropriate.
196  */
197 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
198 {
199         journal_t *journal;
200
201         if (sb->s_flags & MS_RDONLY)
202                 return ERR_PTR(-EROFS);
203
204         /* Special case here: if the journal has aborted behind our
205          * backs (eg. EIO in the commit thread), then we still need to
206          * take the FS itself readonly cleanly. */
207         journal = EXT4_SB(sb)->s_journal;
208         if (journal) {
209                 if (is_journal_aborted(journal)) {
210                         ext4_abort(sb, __func__, "Detected aborted journal");
211                         return ERR_PTR(-EROFS);
212                 }
213                 return jbd2_journal_start(journal, nblocks);
214         }
215         /*
216          * We're not journaling, return the appropriate indication.
217          */
218         current->journal_info = EXT4_NOJOURNAL_HANDLE;
219         return current->journal_info;
220 }
221
222 /*
223  * The only special thing we need to do here is to make sure that all
224  * jbd2_journal_stop calls result in the superblock being marked dirty, so
225  * that sync() will call the filesystem's write_super callback if
226  * appropriate.
227  */
228 int __ext4_journal_stop(const char *where, handle_t *handle)
229 {
230         struct super_block *sb;
231         int err;
232         int rc;
233
234         if (!ext4_handle_valid(handle)) {
235                 /*
236                  * Do this here since we don't call jbd2_journal_stop() in
237                  * no-journal mode.
238                  */
239                 current->journal_info = NULL;
240                 return 0;
241         }
242         sb = handle->h_transaction->t_journal->j_private;
243         err = handle->h_err;
244         rc = jbd2_journal_stop(handle);
245
246         if (!err)
247                 err = rc;
248         if (err)
249                 __ext4_std_error(sb, where, err);
250         return err;
251 }
252
253 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
254                 struct buffer_head *bh, handle_t *handle, int err)
255 {
256         char nbuf[16];
257         const char *errstr = ext4_decode_error(NULL, err, nbuf);
258
259         BUG_ON(!ext4_handle_valid(handle));
260
261         if (bh)
262                 BUFFER_TRACE(bh, "abort");
263
264         if (!handle->h_err)
265                 handle->h_err = err;
266
267         if (is_handle_aborted(handle))
268                 return;
269
270         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
271                caller, errstr, err_fn);
272
273         jbd2_journal_abort_handle(handle);
274 }
275
276 /* Deal with the reporting of failure conditions on a filesystem such as
277  * inconsistencies detected or read IO failures.
278  *
279  * On ext2, we can store the error state of the filesystem in the
280  * superblock.  That is not possible on ext4, because we may have other
281  * write ordering constraints on the superblock which prevent us from
282  * writing it out straight away; and given that the journal is about to
283  * be aborted, we can't rely on the current, or future, transactions to
284  * write out the superblock safely.
285  *
286  * We'll just use the jbd2_journal_abort() error code to record an error in
287  * the journal instead.  On recovery, the journal will compain about
288  * that error until we've noted it down and cleared it.
289  */
290
291 static void ext4_handle_error(struct super_block *sb)
292 {
293         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
294
295         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
296         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
297
298         if (sb->s_flags & MS_RDONLY)
299                 return;
300
301         if (!test_opt(sb, ERRORS_CONT)) {
302                 journal_t *journal = EXT4_SB(sb)->s_journal;
303
304                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
305                 if (journal)
306                         jbd2_journal_abort(journal, -EIO);
307         }
308         if (test_opt(sb, ERRORS_RO)) {
309                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
310                 sb->s_flags |= MS_RDONLY;
311         }
312         ext4_commit_super(sb, 1);
313         if (test_opt(sb, ERRORS_PANIC))
314                 panic("EXT4-fs (device %s): panic forced after error\n",
315                         sb->s_id);
316 }
317
318 void ext4_error(struct super_block *sb, const char *function,
319                 const char *fmt, ...)
320 {
321         va_list args;
322
323         va_start(args, fmt);
324         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
325         vprintk(fmt, args);
326         printk("\n");
327         va_end(args);
328
329         ext4_handle_error(sb);
330 }
331
332 static const char *ext4_decode_error(struct super_block *sb, int errno,
333                                      char nbuf[16])
334 {
335         char *errstr = NULL;
336
337         switch (errno) {
338         case -EIO:
339                 errstr = "IO failure";
340                 break;
341         case -ENOMEM:
342                 errstr = "Out of memory";
343                 break;
344         case -EROFS:
345                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
346                         errstr = "Journal has aborted";
347                 else
348                         errstr = "Readonly filesystem";
349                 break;
350         default:
351                 /* If the caller passed in an extra buffer for unknown
352                  * errors, textualise them now.  Else we just return
353                  * NULL. */
354                 if (nbuf) {
355                         /* Check for truncated error codes... */
356                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
357                                 errstr = nbuf;
358                 }
359                 break;
360         }
361
362         return errstr;
363 }
364
365 /* __ext4_std_error decodes expected errors from journaling functions
366  * automatically and invokes the appropriate error response.  */
367
368 void __ext4_std_error(struct super_block *sb, const char *function, int errno)
369 {
370         char nbuf[16];
371         const char *errstr;
372
373         /* Special case: if the error is EROFS, and we're not already
374          * inside a transaction, then there's really no point in logging
375          * an error. */
376         if (errno == -EROFS && journal_current_handle() == NULL &&
377             (sb->s_flags & MS_RDONLY))
378                 return;
379
380         errstr = ext4_decode_error(sb, errno, nbuf);
381         printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
382                sb->s_id, function, errstr);
383
384         ext4_handle_error(sb);
385 }
386
387 /*
388  * ext4_abort is a much stronger failure handler than ext4_error.  The
389  * abort function may be used to deal with unrecoverable failures such
390  * as journal IO errors or ENOMEM at a critical moment in log management.
391  *
392  * We unconditionally force the filesystem into an ABORT|READONLY state,
393  * unless the error response on the fs has been set to panic in which
394  * case we take the easy way out and panic immediately.
395  */
396
397 void ext4_abort(struct super_block *sb, const char *function,
398                 const char *fmt, ...)
399 {
400         va_list args;
401
402         va_start(args, fmt);
403         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
404         vprintk(fmt, args);
405         printk("\n");
406         va_end(args);
407
408         if (test_opt(sb, ERRORS_PANIC))
409                 panic("EXT4-fs panic from previous error\n");
410
411         if (sb->s_flags & MS_RDONLY)
412                 return;
413
414         ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
415         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
416         sb->s_flags |= MS_RDONLY;
417         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
418         if (EXT4_SB(sb)->s_journal)
419                 jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
420 }
421
422 void ext4_msg (struct super_block * sb, const char *prefix,
423                    const char *fmt, ...)
424 {
425         va_list args;
426
427         va_start(args, fmt);
428         printk("%sEXT4-fs (%s): ", prefix, sb->s_id);
429         vprintk(fmt, args);
430         printk("\n");
431         va_end(args);
432 }
433
434 void ext4_warning(struct super_block *sb, const char *function,
435                   const char *fmt, ...)
436 {
437         va_list args;
438
439         va_start(args, fmt);
440         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
441                sb->s_id, function);
442         vprintk(fmt, args);
443         printk("\n");
444         va_end(args);
445 }
446
447 void ext4_grp_locked_error(struct super_block *sb, ext4_group_t grp,
448                            const char *function, const char *fmt, ...)
449 __releases(bitlock)
450 __acquires(bitlock)
451 {
452         va_list args;
453         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
454
455         va_start(args, fmt);
456         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
457         vprintk(fmt, args);
458         printk("\n");
459         va_end(args);
460
461         if (test_opt(sb, ERRORS_CONT)) {
462                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
463                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
464                 ext4_commit_super(sb, 0);
465                 return;
466         }
467         ext4_unlock_group(sb, grp);
468         ext4_handle_error(sb);
469         /*
470          * We only get here in the ERRORS_RO case; relocking the group
471          * may be dangerous, but nothing bad will happen since the
472          * filesystem will have already been marked read/only and the
473          * journal has been aborted.  We return 1 as a hint to callers
474          * who might what to use the return value from
475          * ext4_grp_locked_error() to distinguish beween the
476          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
477          * aggressively from the ext4 function in question, with a
478          * more appropriate error code.
479          */
480         ext4_lock_group(sb, grp);
481         return;
482 }
483
484 void ext4_update_dynamic_rev(struct super_block *sb)
485 {
486         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
487
488         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
489                 return;
490
491         ext4_warning(sb, __func__,
492                      "updating to rev %d because of new feature flag, "
493                      "running e2fsck is recommended",
494                      EXT4_DYNAMIC_REV);
495
496         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
497         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
498         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
499         /* leave es->s_feature_*compat flags alone */
500         /* es->s_uuid will be set by e2fsck if empty */
501
502         /*
503          * The rest of the superblock fields should be zero, and if not it
504          * means they are likely already in use, so leave them alone.  We
505          * can leave it up to e2fsck to clean up any inconsistencies there.
506          */
507 }
508
509 /*
510  * Open the external journal device
511  */
512 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
513 {
514         struct block_device *bdev;
515         char b[BDEVNAME_SIZE];
516
517         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
518         if (IS_ERR(bdev))
519                 goto fail;
520         return bdev;
521
522 fail:
523         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
524                         __bdevname(dev, b), PTR_ERR(bdev));
525         return NULL;
526 }
527
528 /*
529  * Release the journal device
530  */
531 static int ext4_blkdev_put(struct block_device *bdev)
532 {
533         bd_release(bdev);
534         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
535 }
536
537 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
538 {
539         struct block_device *bdev;
540         int ret = -ENODEV;
541
542         bdev = sbi->journal_bdev;
543         if (bdev) {
544                 ret = ext4_blkdev_put(bdev);
545                 sbi->journal_bdev = NULL;
546         }
547         return ret;
548 }
549
550 static inline struct inode *orphan_list_entry(struct list_head *l)
551 {
552         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
553 }
554
555 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
556 {
557         struct list_head *l;
558
559         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
560                  le32_to_cpu(sbi->s_es->s_last_orphan));
561
562         printk(KERN_ERR "sb_info orphan list:\n");
563         list_for_each(l, &sbi->s_orphan) {
564                 struct inode *inode = orphan_list_entry(l);
565                 printk(KERN_ERR "  "
566                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
567                        inode->i_sb->s_id, inode->i_ino, inode,
568                        inode->i_mode, inode->i_nlink,
569                        NEXT_ORPHAN(inode));
570         }
571 }
572
573 static void ext4_put_super(struct super_block *sb)
574 {
575         struct ext4_sb_info *sbi = EXT4_SB(sb);
576         struct ext4_super_block *es = sbi->s_es;
577         int i, err;
578
579         lock_super(sb);
580         lock_kernel();
581         if (sb->s_dirt)
582                 ext4_commit_super(sb, 1);
583
584         ext4_release_system_zone(sb);
585         ext4_mb_release(sb);
586         ext4_ext_release(sb);
587         ext4_xattr_put_super(sb);
588         if (sbi->s_journal) {
589                 err = jbd2_journal_destroy(sbi->s_journal);
590                 sbi->s_journal = NULL;
591                 if (err < 0)
592                         ext4_abort(sb, __func__,
593                                    "Couldn't clean up the journal");
594         }
595         if (!(sb->s_flags & MS_RDONLY)) {
596                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
597                 es->s_state = cpu_to_le16(sbi->s_mount_state);
598                 ext4_commit_super(sb, 1);
599         }
600         if (sbi->s_proc) {
601                 remove_proc_entry(sb->s_id, ext4_proc_root);
602         }
603         kobject_del(&sbi->s_kobj);
604
605         for (i = 0; i < sbi->s_gdb_count; i++)
606                 brelse(sbi->s_group_desc[i]);
607         kfree(sbi->s_group_desc);
608         if (is_vmalloc_addr(sbi->s_flex_groups))
609                 vfree(sbi->s_flex_groups);
610         else
611                 kfree(sbi->s_flex_groups);
612         percpu_counter_destroy(&sbi->s_freeblocks_counter);
613         percpu_counter_destroy(&sbi->s_freeinodes_counter);
614         percpu_counter_destroy(&sbi->s_dirs_counter);
615         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
616         brelse(sbi->s_sbh);
617 #ifdef CONFIG_QUOTA
618         for (i = 0; i < MAXQUOTAS; i++)
619                 kfree(sbi->s_qf_names[i]);
620 #endif
621
622         /* Debugging code just in case the in-memory inode orphan list
623          * isn't empty.  The on-disk one can be non-empty if we've
624          * detected an error and taken the fs readonly, but the
625          * in-memory list had better be clean by this point. */
626         if (!list_empty(&sbi->s_orphan))
627                 dump_orphan_list(sb, sbi);
628         J_ASSERT(list_empty(&sbi->s_orphan));
629
630         invalidate_bdev(sb->s_bdev);
631         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
632                 /*
633                  * Invalidate the journal device's buffers.  We don't want them
634                  * floating about in memory - the physical journal device may
635                  * hotswapped, and it breaks the `ro-after' testing code.
636                  */
637                 sync_blockdev(sbi->journal_bdev);
638                 invalidate_bdev(sbi->journal_bdev);
639                 ext4_blkdev_remove(sbi);
640         }
641         sb->s_fs_info = NULL;
642         /*
643          * Now that we are completely done shutting down the
644          * superblock, we need to actually destroy the kobject.
645          */
646         unlock_kernel();
647         unlock_super(sb);
648         kobject_put(&sbi->s_kobj);
649         wait_for_completion(&sbi->s_kobj_unregister);
650         kfree(sbi->s_blockgroup_lock);
651         kfree(sbi);
652 }
653
654 static struct kmem_cache *ext4_inode_cachep;
655
656 /*
657  * Called inside transaction, so use GFP_NOFS
658  */
659 static struct inode *ext4_alloc_inode(struct super_block *sb)
660 {
661         struct ext4_inode_info *ei;
662
663         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
664         if (!ei)
665                 return NULL;
666
667 #ifdef CONFIG_EXT4_FS_POSIX_ACL
668         ei->i_acl = EXT4_ACL_NOT_CACHED;
669         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
670 #endif
671         ei->vfs_inode.i_version = 1;
672         ei->vfs_inode.i_data.writeback_index = 0;
673         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
674         INIT_LIST_HEAD(&ei->i_prealloc_list);
675         spin_lock_init(&ei->i_prealloc_lock);
676         /*
677          * Note:  We can be called before EXT4_SB(sb)->s_journal is set,
678          * therefore it can be null here.  Don't check it, just initialize
679          * jinode.
680          */
681         jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
682         ei->i_reserved_data_blocks = 0;
683         ei->i_reserved_meta_blocks = 0;
684         ei->i_allocated_meta_blocks = 0;
685         ei->i_delalloc_reserved_flag = 0;
686         spin_lock_init(&(ei->i_block_reservation_lock));
687
688         return &ei->vfs_inode;
689 }
690
691 static void ext4_destroy_inode(struct inode *inode)
692 {
693         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
694                 ext4_msg(inode->i_sb, KERN_ERR,
695                          "Inode %lu (%p): orphan list check failed!",
696                          inode->i_ino, EXT4_I(inode));
697                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
698                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
699                                 true);
700                 dump_stack();
701         }
702         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
703 }
704
705 static void init_once(void *foo)
706 {
707         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
708
709         INIT_LIST_HEAD(&ei->i_orphan);
710 #ifdef CONFIG_EXT4_FS_XATTR
711         init_rwsem(&ei->xattr_sem);
712 #endif
713         init_rwsem(&ei->i_data_sem);
714         inode_init_once(&ei->vfs_inode);
715 }
716
717 static int init_inodecache(void)
718 {
719         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
720                                              sizeof(struct ext4_inode_info),
721                                              0, (SLAB_RECLAIM_ACCOUNT|
722                                                 SLAB_MEM_SPREAD),
723                                              init_once);
724         if (ext4_inode_cachep == NULL)
725                 return -ENOMEM;
726         return 0;
727 }
728
729 static void destroy_inodecache(void)
730 {
731         kmem_cache_destroy(ext4_inode_cachep);
732 }
733
734 static void ext4_clear_inode(struct inode *inode)
735 {
736 #ifdef CONFIG_EXT4_FS_POSIX_ACL
737         if (EXT4_I(inode)->i_acl &&
738                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
739                 posix_acl_release(EXT4_I(inode)->i_acl);
740                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
741         }
742         if (EXT4_I(inode)->i_default_acl &&
743                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
744                 posix_acl_release(EXT4_I(inode)->i_default_acl);
745                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
746         }
747 #endif
748         ext4_discard_preallocations(inode);
749         if (EXT4_JOURNAL(inode))
750                 jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
751                                        &EXT4_I(inode)->jinode);
752 }
753
754 static inline void ext4_show_quota_options(struct seq_file *seq,
755                                            struct super_block *sb)
756 {
757 #if defined(CONFIG_QUOTA)
758         struct ext4_sb_info *sbi = EXT4_SB(sb);
759
760         if (sbi->s_jquota_fmt)
761                 seq_printf(seq, ",jqfmt=%s",
762                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold" : "vfsv0");
763
764         if (sbi->s_qf_names[USRQUOTA])
765                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
766
767         if (sbi->s_qf_names[GRPQUOTA])
768                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
769
770         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
771                 seq_puts(seq, ",usrquota");
772
773         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
774                 seq_puts(seq, ",grpquota");
775 #endif
776 }
777
778 /*
779  * Show an option if
780  *  - it's set to a non-default value OR
781  *  - if the per-sb default is different from the global default
782  */
783 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
784 {
785         int def_errors;
786         unsigned long def_mount_opts;
787         struct super_block *sb = vfs->mnt_sb;
788         struct ext4_sb_info *sbi = EXT4_SB(sb);
789         struct ext4_super_block *es = sbi->s_es;
790
791         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
792         def_errors     = le16_to_cpu(es->s_errors);
793
794         if (sbi->s_sb_block != 1)
795                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
796         if (test_opt(sb, MINIX_DF))
797                 seq_puts(seq, ",minixdf");
798         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
799                 seq_puts(seq, ",grpid");
800         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
801                 seq_puts(seq, ",nogrpid");
802         if (sbi->s_resuid != EXT4_DEF_RESUID ||
803             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
804                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
805         }
806         if (sbi->s_resgid != EXT4_DEF_RESGID ||
807             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
808                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
809         }
810         if (test_opt(sb, ERRORS_RO)) {
811                 if (def_errors == EXT4_ERRORS_PANIC ||
812                     def_errors == EXT4_ERRORS_CONTINUE) {
813                         seq_puts(seq, ",errors=remount-ro");
814                 }
815         }
816         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
817                 seq_puts(seq, ",errors=continue");
818         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
819                 seq_puts(seq, ",errors=panic");
820         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
821                 seq_puts(seq, ",nouid32");
822         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
823                 seq_puts(seq, ",debug");
824         if (test_opt(sb, OLDALLOC))
825                 seq_puts(seq, ",oldalloc");
826 #ifdef CONFIG_EXT4_FS_XATTR
827         if (test_opt(sb, XATTR_USER) &&
828                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
829                 seq_puts(seq, ",user_xattr");
830         if (!test_opt(sb, XATTR_USER) &&
831             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
832                 seq_puts(seq, ",nouser_xattr");
833         }
834 #endif
835 #ifdef CONFIG_EXT4_FS_POSIX_ACL
836         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
837                 seq_puts(seq, ",acl");
838         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
839                 seq_puts(seq, ",noacl");
840 #endif
841         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
842                 seq_printf(seq, ",commit=%u",
843                            (unsigned) (sbi->s_commit_interval / HZ));
844         }
845         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
846                 seq_printf(seq, ",min_batch_time=%u",
847                            (unsigned) sbi->s_min_batch_time);
848         }
849         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
850                 seq_printf(seq, ",max_batch_time=%u",
851                            (unsigned) sbi->s_min_batch_time);
852         }
853
854         /*
855          * We're changing the default of barrier mount option, so
856          * let's always display its mount state so it's clear what its
857          * status is.
858          */
859         seq_puts(seq, ",barrier=");
860         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
861         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
862                 seq_puts(seq, ",journal_async_commit");
863         if (test_opt(sb, NOBH))
864                 seq_puts(seq, ",nobh");
865         if (test_opt(sb, I_VERSION))
866                 seq_puts(seq, ",i_version");
867         if (!test_opt(sb, DELALLOC))
868                 seq_puts(seq, ",nodelalloc");
869
870
871         if (sbi->s_stripe)
872                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
873         /*
874          * journal mode get enabled in different ways
875          * So just print the value even if we didn't specify it
876          */
877         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
878                 seq_puts(seq, ",data=journal");
879         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
880                 seq_puts(seq, ",data=ordered");
881         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
882                 seq_puts(seq, ",data=writeback");
883
884         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
885                 seq_printf(seq, ",inode_readahead_blks=%u",
886                            sbi->s_inode_readahead_blks);
887
888         if (test_opt(sb, DATA_ERR_ABORT))
889                 seq_puts(seq, ",data_err=abort");
890
891         if (test_opt(sb, NO_AUTO_DA_ALLOC))
892                 seq_puts(seq, ",noauto_da_alloc");
893
894         ext4_show_quota_options(seq, sb);
895
896         return 0;
897 }
898
899 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
900                                         u64 ino, u32 generation)
901 {
902         struct inode *inode;
903
904         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
905                 return ERR_PTR(-ESTALE);
906         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
907                 return ERR_PTR(-ESTALE);
908
909         /* iget isn't really right if the inode is currently unallocated!!
910          *
911          * ext4_read_inode will return a bad_inode if the inode had been
912          * deleted, so we should be safe.
913          *
914          * Currently we don't know the generation for parent directory, so
915          * a generation of 0 means "accept any"
916          */
917         inode = ext4_iget(sb, ino);
918         if (IS_ERR(inode))
919                 return ERR_CAST(inode);
920         if (generation && inode->i_generation != generation) {
921                 iput(inode);
922                 return ERR_PTR(-ESTALE);
923         }
924
925         return inode;
926 }
927
928 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
929                                         int fh_len, int fh_type)
930 {
931         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
932                                     ext4_nfs_get_inode);
933 }
934
935 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
936                                         int fh_len, int fh_type)
937 {
938         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
939                                     ext4_nfs_get_inode);
940 }
941
942 /*
943  * Try to release metadata pages (indirect blocks, directories) which are
944  * mapped via the block device.  Since these pages could have journal heads
945  * which would prevent try_to_free_buffers() from freeing them, we must use
946  * jbd2 layer's try_to_free_buffers() function to release them.
947  */
948 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
949                                  gfp_t wait)
950 {
951         journal_t *journal = EXT4_SB(sb)->s_journal;
952
953         WARN_ON(PageChecked(page));
954         if (!page_has_buffers(page))
955                 return 0;
956         if (journal)
957                 return jbd2_journal_try_to_free_buffers(journal, page,
958                                                         wait & ~__GFP_WAIT);
959         return try_to_free_buffers(page);
960 }
961
962 #ifdef CONFIG_QUOTA
963 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
964 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
965
966 static int ext4_write_dquot(struct dquot *dquot);
967 static int ext4_acquire_dquot(struct dquot *dquot);
968 static int ext4_release_dquot(struct dquot *dquot);
969 static int ext4_mark_dquot_dirty(struct dquot *dquot);
970 static int ext4_write_info(struct super_block *sb, int type);
971 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
972                                 char *path, int remount);
973 static int ext4_quota_on_mount(struct super_block *sb, int type);
974 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
975                                size_t len, loff_t off);
976 static ssize_t ext4_quota_write(struct super_block *sb, int type,
977                                 const char *data, size_t len, loff_t off);
978
979 static struct dquot_operations ext4_quota_operations = {
980         .initialize     = dquot_initialize,
981         .drop           = dquot_drop,
982         .alloc_space    = dquot_alloc_space,
983         .reserve_space  = dquot_reserve_space,
984         .claim_space    = dquot_claim_space,
985         .release_rsv    = dquot_release_reserved_space,
986         .get_reserved_space = ext4_get_reserved_space,
987         .alloc_inode    = dquot_alloc_inode,
988         .free_space     = dquot_free_space,
989         .free_inode     = dquot_free_inode,
990         .transfer       = dquot_transfer,
991         .write_dquot    = ext4_write_dquot,
992         .acquire_dquot  = ext4_acquire_dquot,
993         .release_dquot  = ext4_release_dquot,
994         .mark_dirty     = ext4_mark_dquot_dirty,
995         .write_info     = ext4_write_info,
996         .alloc_dquot    = dquot_alloc,
997         .destroy_dquot  = dquot_destroy,
998 };
999
1000 static struct quotactl_ops ext4_qctl_operations = {
1001         .quota_on       = ext4_quota_on,
1002         .quota_off      = vfs_quota_off,
1003         .quota_sync     = vfs_quota_sync,
1004         .get_info       = vfs_get_dqinfo,
1005         .set_info       = vfs_set_dqinfo,
1006         .get_dqblk      = vfs_get_dqblk,
1007         .set_dqblk      = vfs_set_dqblk
1008 };
1009 #endif
1010
1011 static const struct super_operations ext4_sops = {
1012         .alloc_inode    = ext4_alloc_inode,
1013         .destroy_inode  = ext4_destroy_inode,
1014         .write_inode    = ext4_write_inode,
1015         .dirty_inode    = ext4_dirty_inode,
1016         .delete_inode   = ext4_delete_inode,
1017         .put_super      = ext4_put_super,
1018         .sync_fs        = ext4_sync_fs,
1019         .freeze_fs      = ext4_freeze,
1020         .unfreeze_fs    = ext4_unfreeze,
1021         .statfs         = ext4_statfs,
1022         .remount_fs     = ext4_remount,
1023         .clear_inode    = ext4_clear_inode,
1024         .show_options   = ext4_show_options,
1025 #ifdef CONFIG_QUOTA
1026         .quota_read     = ext4_quota_read,
1027         .quota_write    = ext4_quota_write,
1028 #endif
1029         .bdev_try_to_free_page = bdev_try_to_free_page,
1030 };
1031
1032 static const struct super_operations ext4_nojournal_sops = {
1033         .alloc_inode    = ext4_alloc_inode,
1034         .destroy_inode  = ext4_destroy_inode,
1035         .write_inode    = ext4_write_inode,
1036         .dirty_inode    = ext4_dirty_inode,
1037         .delete_inode   = ext4_delete_inode,
1038         .write_super    = ext4_write_super,
1039         .put_super      = ext4_put_super,
1040         .statfs         = ext4_statfs,
1041         .remount_fs     = ext4_remount,
1042         .clear_inode    = ext4_clear_inode,
1043         .show_options   = ext4_show_options,
1044 #ifdef CONFIG_QUOTA
1045         .quota_read     = ext4_quota_read,
1046         .quota_write    = ext4_quota_write,
1047 #endif
1048         .bdev_try_to_free_page = bdev_try_to_free_page,
1049 };
1050
1051 static const struct export_operations ext4_export_ops = {
1052         .fh_to_dentry = ext4_fh_to_dentry,
1053         .fh_to_parent = ext4_fh_to_parent,
1054         .get_parent = ext4_get_parent,
1055 };
1056
1057 enum {
1058         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1059         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1060         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1061         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1062         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1063         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1064         Opt_journal_update, Opt_journal_dev,
1065         Opt_journal_checksum, Opt_journal_async_commit,
1066         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1067         Opt_data_err_abort, Opt_data_err_ignore, Opt_mb_history_length,
1068         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1069         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
1070         Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err, Opt_resize,
1071         Opt_usrquota, Opt_grpquota, Opt_i_version,
1072         Opt_stripe, Opt_delalloc, Opt_nodelalloc,
1073         Opt_block_validity, Opt_noblock_validity,
1074         Opt_inode_readahead_blks, Opt_journal_ioprio
1075 };
1076
1077 static const match_table_t tokens = {
1078         {Opt_bsd_df, "bsddf"},
1079         {Opt_minix_df, "minixdf"},
1080         {Opt_grpid, "grpid"},
1081         {Opt_grpid, "bsdgroups"},
1082         {Opt_nogrpid, "nogrpid"},
1083         {Opt_nogrpid, "sysvgroups"},
1084         {Opt_resgid, "resgid=%u"},
1085         {Opt_resuid, "resuid=%u"},
1086         {Opt_sb, "sb=%u"},
1087         {Opt_err_cont, "errors=continue"},
1088         {Opt_err_panic, "errors=panic"},
1089         {Opt_err_ro, "errors=remount-ro"},
1090         {Opt_nouid32, "nouid32"},
1091         {Opt_debug, "debug"},
1092         {Opt_oldalloc, "oldalloc"},
1093         {Opt_orlov, "orlov"},
1094         {Opt_user_xattr, "user_xattr"},
1095         {Opt_nouser_xattr, "nouser_xattr"},
1096         {Opt_acl, "acl"},
1097         {Opt_noacl, "noacl"},
1098         {Opt_noload, "noload"},
1099         {Opt_nobh, "nobh"},
1100         {Opt_bh, "bh"},
1101         {Opt_commit, "commit=%u"},
1102         {Opt_min_batch_time, "min_batch_time=%u"},
1103         {Opt_max_batch_time, "max_batch_time=%u"},
1104         {Opt_journal_update, "journal=update"},
1105         {Opt_journal_dev, "journal_dev=%u"},
1106         {Opt_journal_checksum, "journal_checksum"},
1107         {Opt_journal_async_commit, "journal_async_commit"},
1108         {Opt_abort, "abort"},
1109         {Opt_data_journal, "data=journal"},
1110         {Opt_data_ordered, "data=ordered"},
1111         {Opt_data_writeback, "data=writeback"},
1112         {Opt_data_err_abort, "data_err=abort"},
1113         {Opt_data_err_ignore, "data_err=ignore"},
1114         {Opt_mb_history_length, "mb_history_length=%u"},
1115         {Opt_offusrjquota, "usrjquota="},
1116         {Opt_usrjquota, "usrjquota=%s"},
1117         {Opt_offgrpjquota, "grpjquota="},
1118         {Opt_grpjquota, "grpjquota=%s"},
1119         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1120         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1121         {Opt_grpquota, "grpquota"},
1122         {Opt_noquota, "noquota"},
1123         {Opt_quota, "quota"},
1124         {Opt_usrquota, "usrquota"},
1125         {Opt_barrier, "barrier=%u"},
1126         {Opt_barrier, "barrier"},
1127         {Opt_nobarrier, "nobarrier"},
1128         {Opt_i_version, "i_version"},
1129         {Opt_stripe, "stripe=%u"},
1130         {Opt_resize, "resize"},
1131         {Opt_delalloc, "delalloc"},
1132         {Opt_nodelalloc, "nodelalloc"},
1133         {Opt_block_validity, "block_validity"},
1134         {Opt_noblock_validity, "noblock_validity"},
1135         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1136         {Opt_journal_ioprio, "journal_ioprio=%u"},
1137         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1138         {Opt_auto_da_alloc, "auto_da_alloc"},
1139         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1140         {Opt_err, NULL},
1141 };
1142
1143 static ext4_fsblk_t get_sb_block(void **data)
1144 {
1145         ext4_fsblk_t    sb_block;
1146         char            *options = (char *) *data;
1147
1148         if (!options || strncmp(options, "sb=", 3) != 0)
1149                 return 1;       /* Default location */
1150
1151         options += 3;
1152         /* TODO: use simple_strtoll with >32bit ext4 */
1153         sb_block = simple_strtoul(options, &options, 0);
1154         if (*options && *options != ',') {
1155                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1156                        (char *) *data);
1157                 return 1;
1158         }
1159         if (*options == ',')
1160                 options++;
1161         *data = (void *) options;
1162
1163         return sb_block;
1164 }
1165
1166 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1167
1168 static int parse_options(char *options, struct super_block *sb,
1169                          unsigned long *journal_devnum,
1170                          unsigned int *journal_ioprio,
1171                          ext4_fsblk_t *n_blocks_count, int is_remount)
1172 {
1173         struct ext4_sb_info *sbi = EXT4_SB(sb);
1174         char *p;
1175         substring_t args[MAX_OPT_ARGS];
1176         int data_opt = 0;
1177         int option;
1178 #ifdef CONFIG_QUOTA
1179         int qtype, qfmt;
1180         char *qname;
1181 #endif
1182
1183         if (!options)
1184                 return 1;
1185
1186         while ((p = strsep(&options, ",")) != NULL) {
1187                 int token;
1188                 if (!*p)
1189                         continue;
1190
1191                 token = match_token(p, tokens, args);
1192                 switch (token) {
1193                 case Opt_bsd_df:
1194                         clear_opt(sbi->s_mount_opt, MINIX_DF);
1195                         break;
1196                 case Opt_minix_df:
1197                         set_opt(sbi->s_mount_opt, MINIX_DF);
1198                         break;
1199                 case Opt_grpid:
1200                         set_opt(sbi->s_mount_opt, GRPID);
1201                         break;
1202                 case Opt_nogrpid:
1203                         clear_opt(sbi->s_mount_opt, GRPID);
1204                         break;
1205                 case Opt_resuid:
1206                         if (match_int(&args[0], &option))
1207                                 return 0;
1208                         sbi->s_resuid = option;
1209                         break;
1210                 case Opt_resgid:
1211                         if (match_int(&args[0], &option))
1212                                 return 0;
1213                         sbi->s_resgid = option;
1214                         break;
1215                 case Opt_sb:
1216                         /* handled by get_sb_block() instead of here */
1217                         /* *sb_block = match_int(&args[0]); */
1218                         break;
1219                 case Opt_err_panic:
1220                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1221                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1222                         set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1223                         break;
1224                 case Opt_err_ro:
1225                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1226                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1227                         set_opt(sbi->s_mount_opt, ERRORS_RO);
1228                         break;
1229                 case Opt_err_cont:
1230                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1231                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1232                         set_opt(sbi->s_mount_opt, ERRORS_CONT);
1233                         break;
1234                 case Opt_nouid32:
1235                         set_opt(sbi->s_mount_opt, NO_UID32);
1236                         break;
1237                 case Opt_debug:
1238                         set_opt(sbi->s_mount_opt, DEBUG);
1239                         break;
1240                 case Opt_oldalloc:
1241                         set_opt(sbi->s_mount_opt, OLDALLOC);
1242                         break;
1243                 case Opt_orlov:
1244                         clear_opt(sbi->s_mount_opt, OLDALLOC);
1245                         break;
1246 #ifdef CONFIG_EXT4_FS_XATTR
1247                 case Opt_user_xattr:
1248                         set_opt(sbi->s_mount_opt, XATTR_USER);
1249                         break;
1250                 case Opt_nouser_xattr:
1251                         clear_opt(sbi->s_mount_opt, XATTR_USER);
1252                         break;
1253 #else
1254                 case Opt_user_xattr:
1255                 case Opt_nouser_xattr:
1256                         ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1257                         break;
1258 #endif
1259 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1260                 case Opt_acl:
1261                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1262                         break;
1263                 case Opt_noacl:
1264                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1265                         break;
1266 #else
1267                 case Opt_acl:
1268                 case Opt_noacl:
1269                         ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1270                         break;
1271 #endif
1272                 case Opt_journal_update:
1273                         /* @@@ FIXME */
1274                         /* Eventually we will want to be able to create
1275                            a journal file here.  For now, only allow the
1276                            user to specify an existing inode to be the
1277                            journal file. */
1278                         if (is_remount) {
1279                                 ext4_msg(sb, KERN_ERR,
1280                                          "Cannot specify journal on remount");
1281                                 return 0;
1282                         }
1283                         set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1284                         break;
1285                 case Opt_journal_dev:
1286                         if (is_remount) {
1287                                 ext4_msg(sb, KERN_ERR,
1288                                         "Cannot specify journal on remount");
1289                                 return 0;
1290                         }
1291                         if (match_int(&args[0], &option))
1292                                 return 0;
1293                         *journal_devnum = option;
1294                         break;
1295                 case Opt_journal_checksum:
1296                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1297                         break;
1298                 case Opt_journal_async_commit:
1299                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1300                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1301                         break;
1302                 case Opt_noload:
1303                         set_opt(sbi->s_mount_opt, NOLOAD);
1304                         break;
1305                 case Opt_commit:
1306                         if (match_int(&args[0], &option))
1307                                 return 0;
1308                         if (option < 0)
1309                                 return 0;
1310                         if (option == 0)
1311                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1312                         sbi->s_commit_interval = HZ * option;
1313                         break;
1314                 case Opt_max_batch_time:
1315                         if (match_int(&args[0], &option))
1316                                 return 0;
1317                         if (option < 0)
1318                                 return 0;
1319                         if (option == 0)
1320                                 option = EXT4_DEF_MAX_BATCH_TIME;
1321                         sbi->s_max_batch_time = option;
1322                         break;
1323                 case Opt_min_batch_time:
1324                         if (match_int(&args[0], &option))
1325                                 return 0;
1326                         if (option < 0)
1327                                 return 0;
1328                         sbi->s_min_batch_time = option;
1329                         break;
1330                 case Opt_data_journal:
1331                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1332                         goto datacheck;
1333                 case Opt_data_ordered:
1334                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1335                         goto datacheck;
1336                 case Opt_data_writeback:
1337                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1338                 datacheck:
1339                         if (is_remount) {
1340                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1341                                                 != data_opt) {
1342                                         ext4_msg(sb, KERN_ERR,
1343                                                 "Cannot change data mode on remount");
1344                                         return 0;
1345                                 }
1346                         } else {
1347                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1348                                 sbi->s_mount_opt |= data_opt;
1349                         }
1350                         break;
1351                 case Opt_data_err_abort:
1352                         set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1353                         break;
1354                 case Opt_data_err_ignore:
1355                         clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1356                         break;
1357                 case Opt_mb_history_length:
1358                         if (match_int(&args[0], &option))
1359                                 return 0;
1360                         if (option < 0)
1361                                 return 0;
1362                         sbi->s_mb_history_max = option;
1363                         break;
1364 #ifdef CONFIG_QUOTA
1365                 case Opt_usrjquota:
1366                         qtype = USRQUOTA;
1367                         goto set_qf_name;
1368                 case Opt_grpjquota:
1369                         qtype = GRPQUOTA;
1370 set_qf_name:
1371                         if (sb_any_quota_loaded(sb) &&
1372                             !sbi->s_qf_names[qtype]) {
1373                                 ext4_msg(sb, KERN_ERR,
1374                                        "Cannot change journaled "
1375                                        "quota options when quota turned on");
1376                                 return 0;
1377                         }
1378                         qname = match_strdup(&args[0]);
1379                         if (!qname) {
1380                                 ext4_msg(sb, KERN_ERR,
1381                                         "Not enough memory for "
1382                                         "storing quotafile name");
1383                                 return 0;
1384                         }
1385                         if (sbi->s_qf_names[qtype] &&
1386                             strcmp(sbi->s_qf_names[qtype], qname)) {
1387                                 ext4_msg(sb, KERN_ERR,
1388                                         "%s quota file already "
1389                                         "specified", QTYPE2NAME(qtype));
1390                                 kfree(qname);
1391                                 return 0;
1392                         }
1393                         sbi->s_qf_names[qtype] = qname;
1394                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1395                                 ext4_msg(sb, KERN_ERR,
1396                                         "quotafile must be on "
1397                                         "filesystem root");
1398                                 kfree(sbi->s_qf_names[qtype]);
1399                                 sbi->s_qf_names[qtype] = NULL;
1400                                 return 0;
1401                         }
1402                         set_opt(sbi->s_mount_opt, QUOTA);
1403                         break;
1404                 case Opt_offusrjquota:
1405                         qtype = USRQUOTA;
1406                         goto clear_qf_name;
1407                 case Opt_offgrpjquota:
1408                         qtype = GRPQUOTA;
1409 clear_qf_name:
1410                         if (sb_any_quota_loaded(sb) &&
1411                             sbi->s_qf_names[qtype]) {
1412                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1413                                         "journaled quota options when "
1414                                         "quota turned on");
1415                                 return 0;
1416                         }
1417                         /*
1418                          * The space will be released later when all options
1419                          * are confirmed to be correct
1420                          */
1421                         sbi->s_qf_names[qtype] = NULL;
1422                         break;
1423                 case Opt_jqfmt_vfsold:
1424                         qfmt = QFMT_VFS_OLD;
1425                         goto set_qf_format;
1426                 case Opt_jqfmt_vfsv0:
1427                         qfmt = QFMT_VFS_V0;
1428 set_qf_format:
1429                         if (sb_any_quota_loaded(sb) &&
1430                             sbi->s_jquota_fmt != qfmt) {
1431                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1432                                         "journaled quota options when "
1433                                         "quota turned on");
1434                                 return 0;
1435                         }
1436                         sbi->s_jquota_fmt = qfmt;
1437                         break;
1438                 case Opt_quota:
1439                 case Opt_usrquota:
1440                         set_opt(sbi->s_mount_opt, QUOTA);
1441                         set_opt(sbi->s_mount_opt, USRQUOTA);
1442                         break;
1443                 case Opt_grpquota:
1444                         set_opt(sbi->s_mount_opt, QUOTA);
1445                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1446                         break;
1447                 case Opt_noquota:
1448                         if (sb_any_quota_loaded(sb)) {
1449                                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1450                                         "options when quota turned on");
1451                                 return 0;
1452                         }
1453                         clear_opt(sbi->s_mount_opt, QUOTA);
1454                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1455                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1456                         break;
1457 #else
1458                 case Opt_quota:
1459                 case Opt_usrquota:
1460                 case Opt_grpquota:
1461                         ext4_msg(sb, KERN_ERR,
1462                                 "quota options not supported");
1463                         break;
1464                 case Opt_usrjquota:
1465                 case Opt_grpjquota:
1466                 case Opt_offusrjquota:
1467                 case Opt_offgrpjquota:
1468                 case Opt_jqfmt_vfsold:
1469                 case Opt_jqfmt_vfsv0:
1470                         ext4_msg(sb, KERN_ERR,
1471                                 "journaled quota options not supported");
1472                         break;
1473                 case Opt_noquota:
1474                         break;
1475 #endif
1476                 case Opt_abort:
1477                         set_opt(sbi->s_mount_opt, ABORT);
1478                         break;
1479                 case Opt_nobarrier:
1480                         clear_opt(sbi->s_mount_opt, BARRIER);
1481                         break;
1482                 case Opt_barrier:
1483                         if (match_int(&args[0], &option)) {
1484                                 set_opt(sbi->s_mount_opt, BARRIER);
1485                                 break;
1486                         }
1487                         if (option)
1488                                 set_opt(sbi->s_mount_opt, BARRIER);
1489                         else
1490                                 clear_opt(sbi->s_mount_opt, BARRIER);
1491                         break;
1492                 case Opt_ignore:
1493                         break;
1494                 case Opt_resize:
1495                         if (!is_remount) {
1496                                 ext4_msg(sb, KERN_ERR,
1497                                         "resize option only available "
1498                                         "for remount");
1499                                 return 0;
1500                         }
1501                         if (match_int(&args[0], &option) != 0)
1502                                 return 0;
1503                         *n_blocks_count = option;
1504                         break;
1505                 case Opt_nobh:
1506                         set_opt(sbi->s_mount_opt, NOBH);
1507                         break;
1508                 case Opt_bh:
1509                         clear_opt(sbi->s_mount_opt, NOBH);
1510                         break;
1511                 case Opt_i_version:
1512                         set_opt(sbi->s_mount_opt, I_VERSION);
1513                         sb->s_flags |= MS_I_VERSION;
1514                         break;
1515                 case Opt_nodelalloc:
1516                         clear_opt(sbi->s_mount_opt, DELALLOC);
1517                         break;
1518                 case Opt_stripe:
1519                         if (match_int(&args[0], &option))
1520                                 return 0;
1521                         if (option < 0)
1522                                 return 0;
1523                         sbi->s_stripe = option;
1524                         break;
1525                 case Opt_delalloc:
1526                         set_opt(sbi->s_mount_opt, DELALLOC);
1527                         break;
1528                 case Opt_block_validity:
1529                         set_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1530                         break;
1531                 case Opt_noblock_validity:
1532                         clear_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1533                         break;
1534                 case Opt_inode_readahead_blks:
1535                         if (match_int(&args[0], &option))
1536                                 return 0;
1537                         if (option < 0 || option > (1 << 30))
1538                                 return 0;
1539                         if (!is_power_of_2(option)) {
1540                                 ext4_msg(sb, KERN_ERR,
1541                                          "EXT4-fs: inode_readahead_blks"
1542                                          " must be a power of 2");
1543                                 return 0;
1544                         }
1545                         sbi->s_inode_readahead_blks = option;
1546                         break;
1547                 case Opt_journal_ioprio:
1548                         if (match_int(&args[0], &option))
1549                                 return 0;
1550                         if (option < 0 || option > 7)
1551                                 break;
1552                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1553                                                             option);
1554                         break;
1555                 case Opt_noauto_da_alloc:
1556                         set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1557                         break;
1558                 case Opt_auto_da_alloc:
1559                         if (match_int(&args[0], &option)) {
1560                                 clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1561                                 break;
1562                         }
1563                         if (option)
1564                                 clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1565                         else
1566                                 set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1567                         break;
1568                 default:
1569                         ext4_msg(sb, KERN_ERR,
1570                                "Unrecognized mount option \"%s\" "
1571                                "or missing value", p);
1572                         return 0;
1573                 }
1574         }
1575 #ifdef CONFIG_QUOTA
1576         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1577                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1578                      sbi->s_qf_names[USRQUOTA])
1579                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1580
1581                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1582                      sbi->s_qf_names[GRPQUOTA])
1583                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1584
1585                 if ((sbi->s_qf_names[USRQUOTA] &&
1586                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1587                     (sbi->s_qf_names[GRPQUOTA] &&
1588                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1589                         ext4_msg(sb, KERN_ERR, "old and new quota "
1590                                         "format mixing");
1591                         return 0;
1592                 }
1593
1594                 if (!sbi->s_jquota_fmt) {
1595                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1596                                         "not specified");
1597                         return 0;
1598                 }
1599         } else {
1600                 if (sbi->s_jquota_fmt) {
1601                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1602                                         "specified with no journaling "
1603                                         "enabled");
1604                         return 0;
1605                 }
1606         }
1607 #endif
1608         return 1;
1609 }
1610
1611 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1612                             int read_only)
1613 {
1614         struct ext4_sb_info *sbi = EXT4_SB(sb);
1615         int res = 0;
1616
1617         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1618                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1619                          "forcing read-only mode");
1620                 res = MS_RDONLY;
1621         }
1622         if (read_only)
1623                 return res;
1624         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1625                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1626                          "running e2fsck is recommended");
1627         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1628                 ext4_msg(sb, KERN_WARNING,
1629                          "warning: mounting fs with errors, "
1630                          "running e2fsck is recommended");
1631         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1632                  le16_to_cpu(es->s_mnt_count) >=
1633                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1634                 ext4_msg(sb, KERN_WARNING,
1635                          "warning: maximal mount count reached, "
1636                          "running e2fsck is recommended");
1637         else if (le32_to_cpu(es->s_checkinterval) &&
1638                 (le32_to_cpu(es->s_lastcheck) +
1639                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1640                 ext4_msg(sb, KERN_WARNING,
1641                          "warning: checktime reached, "
1642                          "running e2fsck is recommended");
1643         if (!sbi->s_journal)
1644                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1645         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1646                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1647         le16_add_cpu(&es->s_mnt_count, 1);
1648         es->s_mtime = cpu_to_le32(get_seconds());
1649         ext4_update_dynamic_rev(sb);
1650         if (sbi->s_journal)
1651                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1652
1653         ext4_commit_super(sb, 1);
1654         if (test_opt(sb, DEBUG))
1655                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1656                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1657                         sb->s_blocksize,
1658                         sbi->s_groups_count,
1659                         EXT4_BLOCKS_PER_GROUP(sb),
1660                         EXT4_INODES_PER_GROUP(sb),
1661                         sbi->s_mount_opt);
1662
1663         if (EXT4_SB(sb)->s_journal) {
1664                 ext4_msg(sb, KERN_INFO, "%s journal on %s",
1665                        EXT4_SB(sb)->s_journal->j_inode ? "internal" :
1666                        "external", EXT4_SB(sb)->s_journal->j_devname);
1667         } else {
1668                 ext4_msg(sb, KERN_INFO, "no journal");
1669         }
1670         return res;
1671 }
1672
1673 static int ext4_fill_flex_info(struct super_block *sb)
1674 {
1675         struct ext4_sb_info *sbi = EXT4_SB(sb);
1676         struct ext4_group_desc *gdp = NULL;
1677         ext4_group_t flex_group_count;
1678         ext4_group_t flex_group;
1679         int groups_per_flex = 0;
1680         size_t size;
1681         int i;
1682
1683         if (!sbi->s_es->s_log_groups_per_flex) {
1684                 sbi->s_log_groups_per_flex = 0;
1685                 return 1;
1686         }
1687
1688         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1689         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1690
1691         /* We allocate both existing and potentially added groups */
1692         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1693                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1694                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1695         size = flex_group_count * sizeof(struct flex_groups);
1696         sbi->s_flex_groups = kzalloc(size, GFP_KERNEL);
1697         if (sbi->s_flex_groups == NULL) {
1698                 sbi->s_flex_groups = vmalloc(size);
1699                 if (sbi->s_flex_groups)
1700                         memset(sbi->s_flex_groups, 0, size);
1701         }
1702         if (sbi->s_flex_groups == NULL) {
1703                 ext4_msg(sb, KERN_ERR, "not enough memory for "
1704                                 "%u flex groups", flex_group_count);
1705                 goto failed;
1706         }
1707
1708         for (i = 0; i < sbi->s_groups_count; i++) {
1709                 gdp = ext4_get_group_desc(sb, i, NULL);
1710
1711                 flex_group = ext4_flex_group(sbi, i);
1712                 atomic_set(&sbi->s_flex_groups[flex_group].free_inodes,
1713                            ext4_free_inodes_count(sb, gdp));
1714                 atomic_set(&sbi->s_flex_groups[flex_group].free_blocks,
1715                            ext4_free_blks_count(sb, gdp));
1716                 atomic_set(&sbi->s_flex_groups[flex_group].used_dirs,
1717                            ext4_used_dirs_count(sb, gdp));
1718         }
1719
1720         return 1;
1721 failed:
1722         return 0;
1723 }
1724
1725 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1726                             struct ext4_group_desc *gdp)
1727 {
1728         __u16 crc = 0;
1729
1730         if (sbi->s_es->s_feature_ro_compat &
1731             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1732                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1733                 __le32 le_group = cpu_to_le32(block_group);
1734
1735                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1736                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1737                 crc = crc16(crc, (__u8 *)gdp, offset);
1738                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1739                 /* for checksum of struct ext4_group_desc do the rest...*/
1740                 if ((sbi->s_es->s_feature_incompat &
1741                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1742                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1743                         crc = crc16(crc, (__u8 *)gdp + offset,
1744                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1745                                         offset);
1746         }
1747
1748         return cpu_to_le16(crc);
1749 }
1750
1751 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1752                                 struct ext4_group_desc *gdp)
1753 {
1754         if ((sbi->s_es->s_feature_ro_compat &
1755              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1756             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1757                 return 0;
1758
1759         return 1;
1760 }
1761
1762 /* Called at mount-time, super-block is locked */
1763 static int ext4_check_descriptors(struct super_block *sb)
1764 {
1765         struct ext4_sb_info *sbi = EXT4_SB(sb);
1766         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1767         ext4_fsblk_t last_block;
1768         ext4_fsblk_t block_bitmap;
1769         ext4_fsblk_t inode_bitmap;
1770         ext4_fsblk_t inode_table;
1771         int flexbg_flag = 0;
1772         ext4_group_t i;
1773
1774         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1775                 flexbg_flag = 1;
1776
1777         ext4_debug("Checking group descriptors");
1778
1779         for (i = 0; i < sbi->s_groups_count; i++) {
1780                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1781
1782                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1783                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1784                 else
1785                         last_block = first_block +
1786                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1787
1788                 block_bitmap = ext4_block_bitmap(sb, gdp);
1789                 if (block_bitmap < first_block || block_bitmap > last_block) {
1790                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1791                                "Block bitmap for group %u not in group "
1792                                "(block %llu)!", i, block_bitmap);
1793                         return 0;
1794                 }
1795                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1796                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
1797                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1798                                "Inode bitmap for group %u not in group "
1799                                "(block %llu)!", i, inode_bitmap);
1800                         return 0;
1801                 }
1802                 inode_table = ext4_inode_table(sb, gdp);
1803                 if (inode_table < first_block ||
1804                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
1805                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1806                                "Inode table for group %u not in group "
1807                                "(block %llu)!", i, inode_table);
1808                         return 0;
1809                 }
1810                 ext4_lock_group(sb, i);
1811                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1812                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1813                                  "Checksum for group %u failed (%u!=%u)",
1814                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1815                                      gdp)), le16_to_cpu(gdp->bg_checksum));
1816                         if (!(sb->s_flags & MS_RDONLY)) {
1817                                 ext4_unlock_group(sb, i);
1818                                 return 0;
1819                         }
1820                 }
1821                 ext4_unlock_group(sb, i);
1822                 if (!flexbg_flag)
1823                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1824         }
1825
1826         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1827         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
1828         return 1;
1829 }
1830
1831 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1832  * the superblock) which were deleted from all directories, but held open by
1833  * a process at the time of a crash.  We walk the list and try to delete these
1834  * inodes at recovery time (only with a read-write filesystem).
1835  *
1836  * In order to keep the orphan inode chain consistent during traversal (in
1837  * case of crash during recovery), we link each inode into the superblock
1838  * orphan list_head and handle it the same way as an inode deletion during
1839  * normal operation (which journals the operations for us).
1840  *
1841  * We only do an iget() and an iput() on each inode, which is very safe if we
1842  * accidentally point at an in-use or already deleted inode.  The worst that
1843  * can happen in this case is that we get a "bit already cleared" message from
1844  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1845  * e2fsck was run on this filesystem, and it must have already done the orphan
1846  * inode cleanup for us, so we can safely abort without any further action.
1847  */
1848 static void ext4_orphan_cleanup(struct super_block *sb,
1849                                 struct ext4_super_block *es)
1850 {
1851         unsigned int s_flags = sb->s_flags;
1852         int nr_orphans = 0, nr_truncates = 0;
1853 #ifdef CONFIG_QUOTA
1854         int i;
1855 #endif
1856         if (!es->s_last_orphan) {
1857                 jbd_debug(4, "no orphan inodes to clean up\n");
1858                 return;
1859         }
1860
1861         if (bdev_read_only(sb->s_bdev)) {
1862                 ext4_msg(sb, KERN_ERR, "write access "
1863                         "unavailable, skipping orphan cleanup");
1864                 return;
1865         }
1866
1867         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1868                 if (es->s_last_orphan)
1869                         jbd_debug(1, "Errors on filesystem, "
1870                                   "clearing orphan list.\n");
1871                 es->s_last_orphan = 0;
1872                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1873                 return;
1874         }
1875
1876         if (s_flags & MS_RDONLY) {
1877                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
1878                 sb->s_flags &= ~MS_RDONLY;
1879         }
1880 #ifdef CONFIG_QUOTA
1881         /* Needed for iput() to work correctly and not trash data */
1882         sb->s_flags |= MS_ACTIVE;
1883         /* Turn on quotas so that they are updated correctly */
1884         for (i = 0; i < MAXQUOTAS; i++) {
1885                 if (EXT4_SB(sb)->s_qf_names[i]) {
1886                         int ret = ext4_quota_on_mount(sb, i);
1887                         if (ret < 0)
1888                                 ext4_msg(sb, KERN_ERR,
1889                                         "Cannot turn on journaled "
1890                                         "quota: error %d", ret);
1891                 }
1892         }
1893 #endif
1894
1895         while (es->s_last_orphan) {
1896                 struct inode *inode;
1897
1898                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1899                 if (IS_ERR(inode)) {
1900                         es->s_last_orphan = 0;
1901                         break;
1902                 }
1903
1904                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1905                 vfs_dq_init(inode);
1906                 if (inode->i_nlink) {
1907                         ext4_msg(sb, KERN_DEBUG,
1908                                 "%s: truncating inode %lu to %lld bytes",
1909                                 __func__, inode->i_ino, inode->i_size);
1910                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
1911                                   inode->i_ino, inode->i_size);
1912                         ext4_truncate(inode);
1913                         nr_truncates++;
1914                 } else {
1915                         ext4_msg(sb, KERN_DEBUG,
1916                                 "%s: deleting unreferenced inode %lu",
1917                                 __func__, inode->i_ino);
1918                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1919                                   inode->i_ino);
1920                         nr_orphans++;
1921                 }
1922                 iput(inode);  /* The delete magic happens here! */
1923         }
1924
1925 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
1926
1927         if (nr_orphans)
1928                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
1929                        PLURAL(nr_orphans));
1930         if (nr_truncates)
1931                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
1932                        PLURAL(nr_truncates));
1933 #ifdef CONFIG_QUOTA
1934         /* Turn quotas off */
1935         for (i = 0; i < MAXQUOTAS; i++) {
1936                 if (sb_dqopt(sb)->files[i])
1937                         vfs_quota_off(sb, i, 0);
1938         }
1939 #endif
1940         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1941 }
1942
1943 /*
1944  * Maximal extent format file size.
1945  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1946  * extent format containers, within a sector_t, and within i_blocks
1947  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1948  * so that won't be a limiting factor.
1949  *
1950  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1951  */
1952 static loff_t ext4_max_size(int blkbits, int has_huge_files)
1953 {
1954         loff_t res;
1955         loff_t upper_limit = MAX_LFS_FILESIZE;
1956
1957         /* small i_blocks in vfs inode? */
1958         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1959                 /*
1960                  * CONFIG_LBD is not enabled implies the inode
1961                  * i_block represent total blocks in 512 bytes
1962                  * 32 == size of vfs inode i_blocks * 8
1963                  */
1964                 upper_limit = (1LL << 32) - 1;
1965
1966                 /* total blocks in file system block size */
1967                 upper_limit >>= (blkbits - 9);
1968                 upper_limit <<= blkbits;
1969         }
1970
1971         /* 32-bit extent-start container, ee_block */
1972         res = 1LL << 32;
1973         res <<= blkbits;
1974         res -= 1;
1975
1976         /* Sanity check against vm- & vfs- imposed limits */
1977         if (res > upper_limit)
1978                 res = upper_limit;
1979
1980         return res;
1981 }
1982
1983 /*
1984  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1985  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1986  * We need to be 1 filesystem block less than the 2^48 sector limit.
1987  */
1988 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
1989 {
1990         loff_t res = EXT4_NDIR_BLOCKS;
1991         int meta_blocks;
1992         loff_t upper_limit;
1993         /* This is calculated to be the largest file size for a dense, block
1994          * mapped file such that the file's total number of 512-byte sectors,
1995          * including data and all indirect blocks, does not exceed (2^48 - 1).
1996          *
1997          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
1998          * number of 512-byte sectors of the file.
1999          */
2000
2001         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2002                 /*
2003                  * !has_huge_files or CONFIG_LBD not enabled implies that
2004                  * the inode i_block field represents total file blocks in
2005                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2006                  */
2007                 upper_limit = (1LL << 32) - 1;
2008
2009                 /* total blocks in file system block size */
2010                 upper_limit >>= (bits - 9);
2011
2012         } else {
2013                 /*
2014                  * We use 48 bit ext4_inode i_blocks
2015                  * With EXT4_HUGE_FILE_FL set the i_blocks
2016                  * represent total number of blocks in
2017                  * file system block size
2018                  */
2019                 upper_limit = (1LL << 48) - 1;
2020
2021         }
2022
2023         /* indirect blocks */
2024         meta_blocks = 1;
2025         /* double indirect blocks */
2026         meta_blocks += 1 + (1LL << (bits-2));
2027         /* tripple indirect blocks */
2028         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2029
2030         upper_limit -= meta_blocks;
2031         upper_limit <<= bits;
2032
2033         res += 1LL << (bits-2);
2034         res += 1LL << (2*(bits-2));
2035         res += 1LL << (3*(bits-2));
2036         res <<= bits;
2037         if (res > upper_limit)
2038                 res = upper_limit;
2039
2040         if (res > MAX_LFS_FILESIZE)
2041                 res = MAX_LFS_FILESIZE;
2042
2043         return res;
2044 }
2045
2046 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2047                                    ext4_fsblk_t logical_sb_block, int nr)
2048 {
2049         struct ext4_sb_info *sbi = EXT4_SB(sb);
2050         ext4_group_t bg, first_meta_bg;
2051         int has_super = 0;
2052
2053         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2054
2055         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2056             nr < first_meta_bg)
2057                 return logical_sb_block + nr + 1;
2058         bg = sbi->s_desc_per_block * nr;
2059         if (ext4_bg_has_super(sb, bg))
2060                 has_super = 1;
2061
2062         return (has_super + ext4_group_first_block_no(sb, bg));
2063 }
2064
2065 /**
2066  * ext4_get_stripe_size: Get the stripe size.
2067  * @sbi: In memory super block info
2068  *
2069  * If we have specified it via mount option, then
2070  * use the mount option value. If the value specified at mount time is
2071  * greater than the blocks per group use the super block value.
2072  * If the super block value is greater than blocks per group return 0.
2073  * Allocator needs it be less than blocks per group.
2074  *
2075  */
2076 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2077 {
2078         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2079         unsigned long stripe_width =
2080                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2081
2082         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2083                 return sbi->s_stripe;
2084
2085         if (stripe_width <= sbi->s_blocks_per_group)
2086                 return stripe_width;
2087
2088         if (stride <= sbi->s_blocks_per_group)
2089                 return stride;
2090
2091         return 0;
2092 }
2093
2094 /* sysfs supprt */
2095
2096 struct ext4_attr {
2097         struct attribute attr;
2098         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2099         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *, 
2100                          const char *, size_t);
2101         int offset;
2102 };
2103
2104 static int parse_strtoul(const char *buf,
2105                 unsigned long max, unsigned long *value)
2106 {
2107         char *endp;
2108
2109         while (*buf && isspace(*buf))
2110                 buf++;
2111         *value = simple_strtoul(buf, &endp, 0);
2112         while (*endp && isspace(*endp))
2113                 endp++;
2114         if (*endp || *value > max)
2115                 return -EINVAL;
2116
2117         return 0;
2118 }
2119
2120 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2121                                               struct ext4_sb_info *sbi,
2122                                               char *buf)
2123 {
2124         return snprintf(buf, PAGE_SIZE, "%llu\n",
2125                         (s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2126 }
2127
2128 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2129                                          struct ext4_sb_info *sbi, char *buf)
2130 {
2131         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2132
2133         return snprintf(buf, PAGE_SIZE, "%lu\n",
2134                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2135                          sbi->s_sectors_written_start) >> 1);
2136 }
2137
2138 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2139                                           struct ext4_sb_info *sbi, char *buf)
2140 {
2141         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2142
2143         return snprintf(buf, PAGE_SIZE, "%llu\n",
2144                         sbi->s_kbytes_written + 
2145                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2146                           EXT4_SB(sb)->s_sectors_written_start) >> 1));
2147 }
2148
2149 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2150                                           struct ext4_sb_info *sbi,
2151                                           const char *buf, size_t count)
2152 {
2153         unsigned long t;
2154
2155         if (parse_strtoul(buf, 0x40000000, &t))
2156                 return -EINVAL;
2157
2158         if (!is_power_of_2(t))
2159                 return -EINVAL;
2160
2161         sbi->s_inode_readahead_blks = t;
2162         return count;
2163 }
2164
2165 static ssize_t sbi_ui_show(struct ext4_attr *a,
2166                            struct ext4_sb_info *sbi, char *buf)
2167 {
2168         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2169
2170         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2171 }
2172
2173 static ssize_t sbi_ui_store(struct ext4_attr *a,
2174                             struct ext4_sb_info *sbi,
2175                             const char *buf, size_t count)
2176 {
2177         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2178         unsigned long t;
2179
2180         if (parse_strtoul(buf, 0xffffffff, &t))
2181                 return -EINVAL;
2182         *ui = t;
2183         return count;
2184 }
2185
2186 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2187 static struct ext4_attr ext4_attr_##_name = {                   \
2188         .attr = {.name = __stringify(_name), .mode = _mode },   \
2189         .show   = _show,                                        \
2190         .store  = _store,                                       \
2191         .offset = offsetof(struct ext4_sb_info, _elname),       \
2192 }
2193 #define EXT4_ATTR(name, mode, show, store) \
2194 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2195
2196 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2197 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2198 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2199         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2200 #define ATTR_LIST(name) &ext4_attr_##name.attr
2201
2202 EXT4_RO_ATTR(delayed_allocation_blocks);
2203 EXT4_RO_ATTR(session_write_kbytes);
2204 EXT4_RO_ATTR(lifetime_write_kbytes);
2205 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2206                  inode_readahead_blks_store, s_inode_readahead_blks);
2207 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2208 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2209 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2210 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2211 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2212 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2213
2214 static struct attribute *ext4_attrs[] = {
2215         ATTR_LIST(delayed_allocation_blocks),
2216         ATTR_LIST(session_write_kbytes),
2217         ATTR_LIST(lifetime_write_kbytes),
2218         ATTR_LIST(inode_readahead_blks),
2219         ATTR_LIST(mb_stats),
2220         ATTR_LIST(mb_max_to_scan),
2221         ATTR_LIST(mb_min_to_scan),
2222         ATTR_LIST(mb_order2_req),
2223         ATTR_LIST(mb_stream_req),
2224         ATTR_LIST(mb_group_prealloc),
2225         NULL,
2226 };
2227
2228 static ssize_t ext4_attr_show(struct kobject *kobj,
2229                               struct attribute *attr, char *buf)
2230 {
2231         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2232                                                 s_kobj);
2233         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2234
2235         return a->show ? a->show(a, sbi, buf) : 0;
2236 }
2237
2238 static ssize_t ext4_attr_store(struct kobject *kobj,
2239                                struct attribute *attr,
2240                                const char *buf, size_t len)
2241 {
2242         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2243                                                 s_kobj);
2244         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2245
2246         return a->store ? a->store(a, sbi, buf, len) : 0;
2247 }
2248
2249 static void ext4_sb_release(struct kobject *kobj)
2250 {
2251         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2252                                                 s_kobj);
2253         complete(&sbi->s_kobj_unregister);
2254 }
2255
2256
2257 static struct sysfs_ops ext4_attr_ops = {
2258         .show   = ext4_attr_show,
2259         .store  = ext4_attr_store,
2260 };
2261
2262 static struct kobj_type ext4_ktype = {
2263         .default_attrs  = ext4_attrs,
2264         .sysfs_ops      = &ext4_attr_ops,
2265         .release        = ext4_sb_release,
2266 };
2267
2268 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
2269                                 __releases(kernel_lock)
2270                                 __acquires(kernel_lock)
2271 {
2272         struct buffer_head *bh;
2273         struct ext4_super_block *es = NULL;
2274         struct ext4_sb_info *sbi;
2275         ext4_fsblk_t block;
2276         ext4_fsblk_t sb_block = get_sb_block(&data);
2277         ext4_fsblk_t logical_sb_block;
2278         unsigned long offset = 0;
2279         unsigned long journal_devnum = 0;
2280         unsigned long def_mount_opts;
2281         struct inode *root;
2282         char *cp;
2283         const char *descr;
2284         int ret = -EINVAL;
2285         int blocksize;
2286         unsigned int db_count;
2287         unsigned int i;
2288         int needs_recovery, has_huge_files;
2289         int features;
2290         __u64 blocks_count;
2291         int err;
2292         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2293
2294         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2295         if (!sbi)
2296                 return -ENOMEM;
2297
2298         sbi->s_blockgroup_lock =
2299                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
2300         if (!sbi->s_blockgroup_lock) {
2301                 kfree(sbi);
2302                 return -ENOMEM;
2303         }
2304         sb->s_fs_info = sbi;
2305         sbi->s_mount_opt = 0;
2306         sbi->s_resuid = EXT4_DEF_RESUID;
2307         sbi->s_resgid = EXT4_DEF_RESGID;
2308         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
2309         sbi->s_sb_block = sb_block;
2310         sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part,
2311                                                       sectors[1]);
2312
2313         unlock_kernel();
2314
2315         /* Cleanup superblock name */
2316         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
2317                 *cp = '!';
2318
2319         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
2320         if (!blocksize) {
2321                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
2322                 goto out_fail;
2323         }
2324
2325         /*
2326          * The ext4 superblock will not be buffer aligned for other than 1kB
2327          * block sizes.  We need to calculate the offset from buffer start.
2328          */
2329         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
2330                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2331                 offset = do_div(logical_sb_block, blocksize);
2332         } else {
2333                 logical_sb_block = sb_block;
2334         }
2335
2336         if (!(bh = sb_bread(sb, logical_sb_block))) {
2337                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
2338                 goto out_fail;
2339         }
2340         /*
2341          * Note: s_es must be initialized as soon as possible because
2342          *       some ext4 macro-instructions depend on its value
2343          */
2344         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2345         sbi->s_es = es;
2346         sb->s_magic = le16_to_cpu(es->s_magic);
2347         if (sb->s_magic != EXT4_SUPER_MAGIC)
2348                 goto cantfind_ext4;
2349         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
2350
2351         /* Set defaults before we parse the mount options */
2352         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
2353         if (def_mount_opts & EXT4_DEFM_DEBUG)
2354                 set_opt(sbi->s_mount_opt, DEBUG);
2355         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
2356                 set_opt(sbi->s_mount_opt, GRPID);
2357         if (def_mount_opts & EXT4_DEFM_UID16)
2358                 set_opt(sbi->s_mount_opt, NO_UID32);
2359 #ifdef CONFIG_EXT4_FS_XATTR
2360         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
2361                 set_opt(sbi->s_mount_opt, XATTR_USER);
2362 #endif
2363 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2364         if (def_mount_opts & EXT4_DEFM_ACL)
2365                 set_opt(sbi->s_mount_opt, POSIX_ACL);
2366 #endif
2367         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
2368                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
2369         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
2370                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
2371         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
2372                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
2373
2374         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
2375                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
2376         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
2377                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
2378         else
2379                 set_opt(sbi->s_mount_opt, ERRORS_RO);
2380
2381         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
2382         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
2383         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
2384         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
2385         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
2386         sbi->s_mb_history_max = default_mb_history_length;
2387
2388         set_opt(sbi->s_mount_opt, BARRIER);
2389
2390         /*
2391          * enable delayed allocation by default
2392          * Use -o nodelalloc to turn it off
2393          */
2394         set_opt(sbi->s_mount_opt, DELALLOC);
2395
2396         if (!parse_options((char *) data, sb, &journal_devnum,
2397                            &journal_ioprio, NULL, 0))
2398                 goto failed_mount;
2399
2400         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2401                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2402
2403         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
2404             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
2405              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
2406              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
2407                 ext4_msg(sb, KERN_WARNING,
2408                        "feature flags set on rev 0 fs, "
2409                        "running e2fsck is recommended");
2410
2411         /*
2412          * Check feature flags regardless of the revision level, since we
2413          * previously didn't change the revision level when setting the flags,
2414          * so there is a chance incompat flags are set on a rev 0 filesystem.
2415          */
2416         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
2417         if (features) {
2418                 ext4_msg(sb, KERN_ERR,
2419                         "Couldn't mount because of "
2420                         "unsupported optional features (%x)",
2421                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2422                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2423                 goto failed_mount;
2424         }
2425         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
2426         if (!(sb->s_flags & MS_RDONLY) && features) {
2427                 ext4_msg(sb, KERN_ERR,
2428                         "Couldn't mount RDWR because of "
2429                         "unsupported optional features (%x)",
2430                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2431                         ~EXT4_FEATURE_RO_COMPAT_SUPP));
2432                 goto failed_mount;
2433         }
2434         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2435                                     EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
2436         if (has_huge_files) {
2437                 /*
2438                  * Large file size enabled file system can only be
2439                  * mount if kernel is build with CONFIG_LBD
2440                  */
2441                 if (sizeof(root->i_blocks) < sizeof(u64) &&
2442                                 !(sb->s_flags & MS_RDONLY)) {
2443                         ext4_msg(sb, KERN_ERR, "Filesystem with huge "
2444                                         "files cannot be mounted read-write "
2445                                         "without CONFIG_LBD");
2446                         goto failed_mount;
2447                 }
2448         }
2449         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2450
2451         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2452             blocksize > EXT4_MAX_BLOCK_SIZE) {
2453                 ext4_msg(sb, KERN_ERR,
2454                        "Unsupported filesystem blocksize %d", blocksize);
2455                 goto failed_mount;
2456         }
2457
2458         if (sb->s_blocksize != blocksize) {
2459                 /* Validate the filesystem blocksize */
2460                 if (!sb_set_blocksize(sb, blocksize)) {
2461                         ext4_msg(sb, KERN_ERR, "bad block size %d",
2462                                         blocksize);
2463                         goto failed_mount;
2464                 }
2465
2466                 brelse(bh);
2467                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2468                 offset = do_div(logical_sb_block, blocksize);
2469                 bh = sb_bread(sb, logical_sb_block);
2470                 if (!bh) {
2471                         ext4_msg(sb, KERN_ERR,
2472                                "Can't read superblock on 2nd try");
2473                         goto failed_mount;
2474                 }
2475                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2476                 sbi->s_es = es;
2477                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2478                         ext4_msg(sb, KERN_ERR,
2479                                "Magic mismatch, very weird!");
2480                         goto failed_mount;
2481                 }
2482         }
2483
2484         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
2485                                                       has_huge_files);
2486         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
2487
2488         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2489                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2490                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2491         } else {
2492                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2493                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2494                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2495                     (!is_power_of_2(sbi->s_inode_size)) ||
2496                     (sbi->s_inode_size > blocksize)) {
2497                         ext4_msg(sb, KERN_ERR,
2498                                "unsupported inode size: %d",
2499                                sbi->s_inode_size);
2500                         goto failed_mount;
2501                 }
2502                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2503                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2504         }
2505
2506         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2507         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2508                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2509                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2510                     !is_power_of_2(sbi->s_desc_size)) {
2511                         ext4_msg(sb, KERN_ERR,
2512                                "unsupported descriptor size %lu",
2513                                sbi->s_desc_size);
2514                         goto failed_mount;
2515                 }
2516         } else
2517                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2518
2519         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2520         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2521         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2522                 goto cantfind_ext4;
2523
2524         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2525         if (sbi->s_inodes_per_block == 0)
2526                 goto cantfind_ext4;
2527         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2528                                         sbi->s_inodes_per_block;
2529         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2530         sbi->s_sbh = bh;
2531         sbi->s_mount_state = le16_to_cpu(es->s_state);
2532         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2533         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2534
2535         for (i = 0; i < 4; i++)
2536                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2537         sbi->s_def_hash_version = es->s_def_hash_version;
2538         i = le32_to_cpu(es->s_flags);
2539         if (i & EXT2_FLAGS_UNSIGNED_HASH)
2540                 sbi->s_hash_unsigned = 3;
2541         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
2542 #ifdef __CHAR_UNSIGNED__
2543                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
2544                 sbi->s_hash_unsigned = 3;
2545 #else
2546                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
2547 #endif
2548                 sb->s_dirt = 1;
2549         }
2550
2551         if (sbi->s_blocks_per_group > blocksize * 8) {
2552                 ext4_msg(sb, KERN_ERR,
2553                        "#blocks per group too big: %lu",
2554                        sbi->s_blocks_per_group);
2555                 goto failed_mount;
2556         }
2557         if (sbi->s_inodes_per_group > blocksize * 8) {
2558                 ext4_msg(sb, KERN_ERR,
2559                        "#inodes per group too big: %lu",
2560                        sbi->s_inodes_per_group);
2561                 goto failed_mount;
2562         }
2563
2564         if (ext4_blocks_count(es) >
2565                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2566                 ext4_msg(sb, KERN_ERR, "filesystem"
2567                         " too large to mount safely");
2568                 if (sizeof(sector_t) < 8)
2569                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBD not enabled");
2570                 goto failed_mount;
2571         }
2572
2573         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2574                 goto cantfind_ext4;
2575
2576         /* check blocks count against device size */
2577         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
2578         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
2579                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
2580                        "exceeds size of device (%llu blocks)",
2581                        ext4_blocks_count(es), blocks_count);
2582                 goto failed_mount;
2583         }
2584
2585         /*
2586          * It makes no sense for the first data block to be beyond the end
2587          * of the filesystem.
2588          */
2589         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
2590                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
2591                          "block %u is beyond end of filesystem (%llu)",
2592                          le32_to_cpu(es->s_first_data_block),
2593                          ext4_blocks_count(es));
2594                 goto failed_mount;
2595         }
2596         blocks_count = (ext4_blocks_count(es) -
2597                         le32_to_cpu(es->s_first_data_block) +
2598                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2599         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2600         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
2601                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
2602                        "(block count %llu, first data block %u, "
2603                        "blocks per group %lu)", sbi->s_groups_count,
2604                        ext4_blocks_count(es),
2605                        le32_to_cpu(es->s_first_data_block),
2606                        EXT4_BLOCKS_PER_GROUP(sb));
2607                 goto failed_mount;
2608         }
2609         sbi->s_groups_count = blocks_count;
2610         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2611                    EXT4_DESC_PER_BLOCK(sb);
2612         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2613                                     GFP_KERNEL);
2614         if (sbi->s_group_desc == NULL) {
2615                 ext4_msg(sb, KERN_ERR, "not enough memory");
2616                 goto failed_mount;
2617         }
2618
2619 #ifdef CONFIG_PROC_FS
2620         if (ext4_proc_root)
2621                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
2622 #endif
2623
2624         bgl_lock_init(sbi->s_blockgroup_lock);
2625
2626         for (i = 0; i < db_count; i++) {
2627                 block = descriptor_loc(sb, logical_sb_block, i);
2628                 sbi->s_group_desc[i] = sb_bread(sb, block);
2629                 if (!sbi->s_group_desc[i]) {
2630                         ext4_msg(sb, KERN_ERR,
2631                                "can't read group descriptor %d", i);
2632                         db_count = i;
2633                         goto failed_mount2;
2634                 }
2635         }
2636         if (!ext4_check_descriptors(sb)) {
2637                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
2638                 goto failed_mount2;
2639         }
2640         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2641                 if (!ext4_fill_flex_info(sb)) {
2642                         ext4_msg(sb, KERN_ERR,
2643                                "unable to initialize "
2644                                "flex_bg meta info!");
2645                         goto failed_mount2;
2646                 }
2647
2648         sbi->s_gdb_count = db_count;
2649         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2650         spin_lock_init(&sbi->s_next_gen_lock);
2651
2652         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2653                         ext4_count_free_blocks(sb));
2654         if (!err) {
2655                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2656                                 ext4_count_free_inodes(sb));
2657         }
2658         if (!err) {
2659                 err = percpu_counter_init(&sbi->s_dirs_counter,
2660                                 ext4_count_dirs(sb));
2661         }
2662         if (!err) {
2663                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
2664         }
2665         if (err) {
2666                 ext4_msg(sb, KERN_ERR, "insufficient memory");
2667                 goto failed_mount3;
2668         }
2669
2670         sbi->s_stripe = ext4_get_stripe_size(sbi);
2671
2672         /*
2673          * set up enough so that it can read an inode
2674          */
2675         if (!test_opt(sb, NOLOAD) &&
2676             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
2677                 sb->s_op = &ext4_sops;
2678         else
2679                 sb->s_op = &ext4_nojournal_sops;
2680         sb->s_export_op = &ext4_export_ops;
2681         sb->s_xattr = ext4_xattr_handlers;
2682 #ifdef CONFIG_QUOTA
2683         sb->s_qcop = &ext4_qctl_operations;
2684         sb->dq_op = &ext4_quota_operations;
2685 #endif
2686         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2687         mutex_init(&sbi->s_orphan_lock);
2688         mutex_init(&sbi->s_resize_lock);
2689
2690         sb->s_root = NULL;
2691
2692         needs_recovery = (es->s_last_orphan != 0 ||
2693                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2694                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2695
2696         /*
2697          * The first inode we look at is the journal inode.  Don't try
2698          * root first: it may be modified in the journal!
2699          */
2700         if (!test_opt(sb, NOLOAD) &&
2701             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2702                 if (ext4_load_journal(sb, es, journal_devnum))
2703                         goto failed_mount3;
2704                 if (!(sb->s_flags & MS_RDONLY) &&
2705                     EXT4_SB(sb)->s_journal->j_failed_commit) {
2706                         ext4_msg(sb, KERN_CRIT, "error: "
2707                                "ext4_fill_super: Journal transaction "
2708                                "%u is corrupt",
2709                                EXT4_SB(sb)->s_journal->j_failed_commit);
2710                         if (test_opt(sb, ERRORS_RO)) {
2711                                 ext4_msg(sb, KERN_CRIT,
2712                                        "Mounting filesystem read-only");
2713                                 sb->s_flags |= MS_RDONLY;
2714                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2715                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2716                         }
2717                         if (test_opt(sb, ERRORS_PANIC)) {
2718                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2719                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2720                                 ext4_commit_super(sb, 1);
2721                                 goto failed_mount4;
2722                         }
2723                 }
2724         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
2725               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2726                 ext4_msg(sb, KERN_ERR, "required journal recovery "
2727                        "suppressed and not mounted read-only");
2728                 goto failed_mount4;
2729         } else {
2730                 clear_opt(sbi->s_mount_opt, DATA_FLAGS);
2731                 set_opt(sbi->s_mount_opt, WRITEBACK_DATA);
2732                 sbi->s_journal = NULL;
2733                 needs_recovery = 0;
2734                 goto no_journal;
2735         }
2736
2737         if (ext4_blocks_count(es) > 0xffffffffULL &&
2738             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2739                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2740                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
2741                 goto failed_mount4;
2742         }
2743
2744         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2745                 jbd2_journal_set_features(sbi->s_journal,
2746                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2747                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2748         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2749                 jbd2_journal_set_features(sbi->s_journal,
2750                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2751                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2752                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2753         } else {
2754                 jbd2_journal_clear_features(sbi->s_journal,
2755                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2756                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2757         }
2758
2759         /* We have now updated the journal if required, so we can
2760          * validate the data journaling mode. */
2761         switch (test_opt(sb, DATA_FLAGS)) {
2762         case 0:
2763                 /* No mode set, assume a default based on the journal
2764                  * capabilities: ORDERED_DATA if the journal can
2765                  * cope, else JOURNAL_DATA
2766                  */
2767                 if (jbd2_journal_check_available_features
2768                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2769                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2770                 else
2771                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2772                 break;
2773
2774         case EXT4_MOUNT_ORDERED_DATA:
2775         case EXT4_MOUNT_WRITEBACK_DATA:
2776                 if (!jbd2_journal_check_available_features
2777                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2778                         ext4_msg(sb, KERN_ERR, "Journal does not support "
2779                                "requested data journaling mode");
2780                         goto failed_mount4;
2781                 }
2782         default:
2783                 break;
2784         }
2785         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
2786
2787 no_journal:
2788
2789         if (test_opt(sb, NOBH)) {
2790                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2791                         ext4_msg(sb, KERN_WARNING, "Ignoring nobh option - "
2792                                 "its supported only with writeback mode");
2793                         clear_opt(sbi->s_mount_opt, NOBH);
2794                 }
2795         }
2796         /*
2797          * The jbd2_journal_load will have done any necessary log recovery,
2798          * so we can safely mount the rest of the filesystem now.
2799          */
2800
2801         root = ext4_iget(sb, EXT4_ROOT_INO);
2802         if (IS_ERR(root)) {
2803                 ext4_msg(sb, KERN_ERR, "get root inode failed");
2804                 ret = PTR_ERR(root);
2805                 goto failed_mount4;
2806         }
2807         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2808                 iput(root);
2809                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
2810                 goto failed_mount4;
2811         }
2812         sb->s_root = d_alloc_root(root);
2813         if (!sb->s_root) {
2814                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
2815                 iput(root);
2816                 ret = -ENOMEM;
2817                 goto failed_mount4;
2818         }
2819
2820         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
2821
2822         /* determine the minimum size of new large inodes, if present */
2823         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2824                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2825                                                      EXT4_GOOD_OLD_INODE_SIZE;
2826                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2827                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2828                         if (sbi->s_want_extra_isize <
2829                             le16_to_cpu(es->s_want_extra_isize))
2830                                 sbi->s_want_extra_isize =
2831                                         le16_to_cpu(es->s_want_extra_isize);
2832                         if (sbi->s_want_extra_isize <
2833                             le16_to_cpu(es->s_min_extra_isize))
2834                                 sbi->s_want_extra_isize =
2835                                         le16_to_cpu(es->s_min_extra_isize);
2836                 }
2837         }
2838         /* Check if enough inode space is available */
2839         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2840                                                         sbi->s_inode_size) {
2841                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2842                                                        EXT4_GOOD_OLD_INODE_SIZE;
2843                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
2844                          "available");
2845         }
2846
2847         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
2848                 ext4_msg(sb, KERN_WARNING, "Ignoring delalloc option - "
2849                          "requested data journaling mode");
2850                 clear_opt(sbi->s_mount_opt, DELALLOC);
2851         } else if (test_opt(sb, DELALLOC))
2852                 ext4_msg(sb, KERN_INFO, "delayed allocation enabled");
2853
2854         err = ext4_setup_system_zone(sb);
2855         if (err) {
2856                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
2857                          "zone (%d)\n", err);
2858                 goto failed_mount4;
2859         }
2860
2861         ext4_ext_init(sb);
2862         err = ext4_mb_init(sb, needs_recovery);
2863         if (err) {
2864                 ext4_msg(sb, KERN_ERR, "failed to initalize mballoc (%d)",
2865                          err);
2866                 goto failed_mount4;
2867         }
2868
2869         sbi->s_kobj.kset = ext4_kset;
2870         init_completion(&sbi->s_kobj_unregister);
2871         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
2872                                    "%s", sb->s_id);
2873         if (err) {
2874                 ext4_mb_release(sb);
2875                 ext4_ext_release(sb);
2876                 goto failed_mount4;
2877         };
2878
2879         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2880         ext4_orphan_cleanup(sb, es);
2881         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2882         if (needs_recovery) {
2883                 ext4_msg(sb, KERN_INFO, "recovery complete");
2884                 ext4_mark_recovery_complete(sb, es);
2885         }
2886         if (EXT4_SB(sb)->s_journal) {
2887                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2888                         descr = " journalled data mode";
2889                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2890                         descr = " ordered data mode";
2891                 else
2892                         descr = " writeback data mode";
2893         } else
2894                 descr = "out journal";
2895
2896         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s", descr);
2897
2898         lock_kernel();
2899         return 0;
2900
2901 cantfind_ext4:
2902         if (!silent)
2903                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
2904         goto failed_mount;
2905
2906 failed_mount4:
2907         ext4_msg(sb, KERN_ERR, "mount failed");
2908         ext4_release_system_zone(sb);
2909         if (sbi->s_journal) {
2910                 jbd2_journal_destroy(sbi->s_journal);
2911                 sbi->s_journal = NULL;
2912         }
2913 failed_mount3:
2914         if (sbi->s_flex_groups) {
2915                 if (is_vmalloc_addr(sbi->s_flex_groups))
2916                         vfree(sbi->s_flex_groups);
2917                 else
2918                         kfree(sbi->s_flex_groups);
2919         }
2920         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2921         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2922         percpu_counter_destroy(&sbi->s_dirs_counter);
2923         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
2924 failed_mount2:
2925         for (i = 0; i < db_count; i++)
2926                 brelse(sbi->s_group_desc[i]);
2927         kfree(sbi->s_group_desc);
2928 failed_mount:
2929         if (sbi->s_proc) {
2930                 remove_proc_entry(sb->s_id, ext4_proc_root);
2931         }
2932 #ifdef CONFIG_QUOTA
2933         for (i = 0; i < MAXQUOTAS; i++)
2934                 kfree(sbi->s_qf_names[i]);
2935 #endif
2936         ext4_blkdev_remove(sbi);
2937         brelse(bh);
2938 out_fail:
2939         sb->s_fs_info = NULL;
2940         kfree(sbi->s_blockgroup_lock);
2941         kfree(sbi);
2942         lock_kernel();
2943         return ret;
2944 }
2945
2946 /*
2947  * Setup any per-fs journal parameters now.  We'll do this both on
2948  * initial mount, once the journal has been initialised but before we've
2949  * done any recovery; and again on any subsequent remount.
2950  */
2951 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2952 {
2953         struct ext4_sb_info *sbi = EXT4_SB(sb);
2954
2955         journal->j_commit_interval = sbi->s_commit_interval;
2956         journal->j_min_batch_time = sbi->s_min_batch_time;
2957         journal->j_max_batch_time = sbi->s_max_batch_time;
2958
2959         spin_lock(&journal->j_state_lock);
2960         if (test_opt(sb, BARRIER))
2961                 journal->j_flags |= JBD2_BARRIER;
2962         else
2963                 journal->j_flags &= ~JBD2_BARRIER;
2964         if (test_opt(sb, DATA_ERR_ABORT))
2965                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
2966         else
2967                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
2968         spin_unlock(&journal->j_state_lock);
2969 }
2970
2971 static journal_t *ext4_get_journal(struct super_block *sb,
2972                                    unsigned int journal_inum)
2973 {
2974         struct inode *journal_inode;
2975         journal_t *journal;
2976
2977         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2978
2979         /* First, test for the existence of a valid inode on disk.  Bad
2980          * things happen if we iget() an unused inode, as the subsequent
2981          * iput() will try to delete it. */
2982
2983         journal_inode = ext4_iget(sb, journal_inum);
2984         if (IS_ERR(journal_inode)) {
2985                 ext4_msg(sb, KERN_ERR, "no journal found");
2986                 return NULL;
2987         }
2988         if (!journal_inode->i_nlink) {
2989                 make_bad_inode(journal_inode);
2990                 iput(journal_inode);
2991                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
2992                 return NULL;
2993         }
2994
2995         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
2996                   journal_inode, journal_inode->i_size);
2997         if (!S_ISREG(journal_inode->i_mode)) {
2998                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
2999                 iput(journal_inode);
3000                 return NULL;
3001         }
3002
3003         journal = jbd2_journal_init_inode(journal_inode);
3004         if (!journal) {
3005                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3006                 iput(journal_inode);
3007                 return NULL;
3008         }
3009         journal->j_private = sb;
3010         ext4_init_journal_params(sb, journal);
3011         return journal;
3012 }
3013
3014 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3015                                        dev_t j_dev)
3016 {
3017         struct buffer_head *bh;
3018         journal_t *journal;
3019         ext4_fsblk_t start;
3020         ext4_fsblk_t len;
3021         int hblock, blocksize;
3022         ext4_fsblk_t sb_block;
3023         unsigned long offset;
3024         struct ext4_super_block *es;
3025         struct block_device *bdev;
3026
3027         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3028
3029         bdev = ext4_blkdev_get(j_dev, sb);
3030         if (bdev == NULL)
3031                 return NULL;
3032
3033         if (bd_claim(bdev, sb)) {
3034                 ext4_msg(sb, KERN_ERR,
3035                         "failed to claim external journal device");
3036                 blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
3037                 return NULL;
3038         }
3039
3040         blocksize = sb->s_blocksize;
3041         hblock = bdev_logical_block_size(bdev);
3042         if (blocksize < hblock) {
3043                 ext4_msg(sb, KERN_ERR,
3044                         "blocksize too small for journal device");
3045                 goto out_bdev;
3046         }
3047
3048         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3049         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3050         set_blocksize(bdev, blocksize);
3051         if (!(bh = __bread(bdev, sb_block, blocksize))) {
3052                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3053                        "external journal");
3054                 goto out_bdev;
3055         }
3056
3057         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3058         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3059             !(le32_to_cpu(es->s_feature_incompat) &
3060               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3061                 ext4_msg(sb, KERN_ERR, "external journal has "
3062                                         "bad superblock");
3063                 brelse(bh);
3064                 goto out_bdev;
3065         }
3066
3067         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3068                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3069                 brelse(bh);
3070                 goto out_bdev;
3071         }
3072
3073         len = ext4_blocks_count(es);
3074         start = sb_block + 1;
3075         brelse(bh);     /* we're done with the superblock */
3076
3077         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3078                                         start, len, blocksize);
3079         if (!journal) {
3080                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
3081                 goto out_bdev;
3082         }
3083         journal->j_private = sb;
3084         ll_rw_block(READ, 1, &journal->j_sb_buffer);
3085         wait_on_buffer(journal->j_sb_buffer);
3086         if (!buffer_uptodate(journal->j_sb_buffer)) {
3087                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3088                 goto out_journal;
3089         }
3090         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3091                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
3092                                         "user (unsupported) - %d",
3093                         be32_to_cpu(journal->j_superblock->s_nr_users));
3094                 goto out_journal;
3095         }
3096         EXT4_SB(sb)->journal_bdev = bdev;
3097         ext4_init_journal_params(sb, journal);
3098         return journal;
3099
3100 out_journal:
3101         jbd2_journal_destroy(journal);
3102 out_bdev:
3103         ext4_blkdev_put(bdev);
3104         return NULL;
3105 }
3106
3107 static int ext4_load_journal(struct super_block *sb,
3108                              struct ext4_super_block *es,
3109                              unsigned long journal_devnum)
3110 {
3111         journal_t *journal;
3112         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3113         dev_t journal_dev;
3114         int err = 0;
3115         int really_read_only;
3116
3117         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3118
3119         if (journal_devnum &&
3120             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3121                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3122                         "numbers have changed");
3123                 journal_dev = new_decode_dev(journal_devnum);
3124         } else
3125                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3126
3127         really_read_only = bdev_read_only(sb->s_bdev);
3128
3129         /*
3130          * Are we loading a blank journal or performing recovery after a
3131          * crash?  For recovery, we need to check in advance whether we
3132          * can get read-write access to the device.
3133          */
3134         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3135                 if (sb->s_flags & MS_RDONLY) {
3136                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
3137                                         "required on readonly filesystem");
3138                         if (really_read_only) {
3139                                 ext4_msg(sb, KERN_ERR, "write access "
3140                                         "unavailable, cannot proceed");
3141                                 return -EROFS;
3142                         }
3143                         ext4_msg(sb, KERN_INFO, "write access will "
3144                                "be enabled during recovery");
3145                 }
3146         }
3147
3148         if (journal_inum && journal_dev) {
3149                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3150                        "and inode journals!");
3151                 return -EINVAL;
3152         }
3153
3154         if (journal_inum) {
3155                 if (!(journal = ext4_get_journal(sb, journal_inum)))
3156                         return -EINVAL;
3157         } else {
3158                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3159                         return -EINVAL;
3160         }
3161
3162         if (journal->j_flags & JBD2_BARRIER)
3163                 ext4_msg(sb, KERN_INFO, "barriers enabled");
3164         else
3165                 ext4_msg(sb, KERN_INFO, "barriers disabled");
3166
3167         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
3168                 err = jbd2_journal_update_format(journal);
3169                 if (err)  {
3170                         ext4_msg(sb, KERN_ERR, "error updating journal");
3171                         jbd2_journal_destroy(journal);
3172                         return err;
3173                 }
3174         }
3175
3176         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3177                 err = jbd2_journal_wipe(journal, !really_read_only);
3178         if (!err)
3179                 err = jbd2_journal_load(journal);
3180
3181         if (err) {
3182                 ext4_msg(sb, KERN_ERR, "error loading journal");
3183                 jbd2_journal_destroy(journal);
3184                 return err;
3185         }
3186
3187         EXT4_SB(sb)->s_journal = journal;
3188         ext4_clear_journal_err(sb, es);
3189
3190         if (journal_devnum &&
3191             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3192                 es->s_journal_dev = cpu_to_le32(journal_devnum);
3193
3194                 /* Make sure we flush the recovery flag to disk. */
3195                 ext4_commit_super(sb, 1);
3196         }
3197
3198         return 0;
3199 }
3200
3201 static int ext4_commit_super(struct super_block *sb, int sync)
3202 {
3203         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
3204         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3205         int error = 0;
3206
3207         if (!sbh)
3208                 return error;
3209         if (buffer_write_io_error(sbh)) {
3210                 /*
3211                  * Oh, dear.  A previous attempt to write the
3212                  * superblock failed.  This could happen because the
3213                  * USB device was yanked out.  Or it could happen to
3214                  * be a transient write error and maybe the block will
3215                  * be remapped.  Nothing we can do but to retry the
3216                  * write and hope for the best.
3217                  */
3218                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
3219                        "superblock detected");
3220                 clear_buffer_write_io_error(sbh);
3221                 set_buffer_uptodate(sbh);
3222         }
3223         es->s_wtime = cpu_to_le32(get_seconds());
3224         es->s_kbytes_written =
3225                 cpu_to_le64(EXT4_SB(sb)->s_kbytes_written + 
3226                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
3227                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
3228         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
3229                                         &EXT4_SB(sb)->s_freeblocks_counter));
3230         es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(
3231                                         &EXT4_SB(sb)->s_freeinodes_counter));
3232         sb->s_dirt = 0;
3233         BUFFER_TRACE(sbh, "marking dirty");
3234         mark_buffer_dirty(sbh);
3235         if (sync) {
3236                 error = sync_dirty_buffer(sbh);
3237                 if (error)
3238                         return error;
3239
3240                 error = buffer_write_io_error(sbh);
3241                 if (error) {
3242                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
3243                                "superblock");
3244                         clear_buffer_write_io_error(sbh);
3245                         set_buffer_uptodate(sbh);
3246                 }
3247         }
3248         return error;
3249 }
3250
3251 /*
3252  * Have we just finished recovery?  If so, and if we are mounting (or
3253  * remounting) the filesystem readonly, then we will end up with a
3254  * consistent fs on disk.  Record that fact.
3255  */
3256 static void ext4_mark_recovery_complete(struct super_block *sb,
3257                                         struct ext4_super_block *es)
3258 {
3259         journal_t *journal = EXT4_SB(sb)->s_journal;
3260
3261         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3262                 BUG_ON(journal != NULL);
3263                 return;
3264         }
3265         jbd2_journal_lock_updates(journal);
3266         if (jbd2_journal_flush(journal) < 0)
3267                 goto out;
3268
3269         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
3270             sb->s_flags & MS_RDONLY) {
3271                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3272                 ext4_commit_super(sb, 1);
3273         }
3274
3275 out:
3276         jbd2_journal_unlock_updates(journal);
3277 }
3278
3279 /*
3280  * If we are mounting (or read-write remounting) a filesystem whose journal
3281  * has recorded an error from a previous lifetime, move that error to the
3282  * main filesystem now.
3283  */
3284 static void ext4_clear_journal_err(struct super_block *sb,
3285                                    struct ext4_super_block *es)
3286 {
3287         journal_t *journal;
3288         int j_errno;
3289         const char *errstr;
3290
3291         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3292
3293         journal = EXT4_SB(sb)->s_journal;
3294
3295         /*
3296          * Now check for any error status which may have been recorded in the
3297          * journal by a prior ext4_error() or ext4_abort()
3298          */
3299
3300         j_errno = jbd2_journal_errno(journal);
3301         if (j_errno) {
3302                 char nbuf[16];
3303
3304                 errstr = ext4_decode_error(sb, j_errno, nbuf);
3305                 ext4_warning(sb, __func__, "Filesystem error recorded "
3306                              "from previous mount: %s", errstr);
3307                 ext4_warning(sb, __func__, "Marking fs in need of "
3308                              "filesystem check.");
3309
3310                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
3311                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
3312                 ext4_commit_super(sb, 1);
3313
3314                 jbd2_journal_clear_err(journal);
3315         }
3316 }
3317
3318 /*
3319  * Force the running and committing transactions to commit,
3320  * and wait on the commit.
3321  */
3322 int ext4_force_commit(struct super_block *sb)
3323 {
3324         journal_t *journal;
3325         int ret = 0;
3326
3327         if (sb->s_flags & MS_RDONLY)
3328                 return 0;
3329
3330         journal = EXT4_SB(sb)->s_journal;
3331         if (journal)
3332                 ret = ext4_journal_force_commit(journal);
3333
3334         return ret;
3335 }
3336
3337 static void ext4_write_super(struct super_block *sb)
3338 {
3339         lock_super(sb);
3340         ext4_commit_super(sb, 1);
3341         unlock_super(sb);
3342 }
3343
3344 static int ext4_sync_fs(struct super_block *sb, int wait)
3345 {
3346         int ret = 0;
3347         tid_t target;
3348
3349         trace_mark(ext4_sync_fs, "dev %s wait %d", sb->s_id, wait);
3350         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
3351                 if (wait)
3352                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
3353         }
3354         return ret;
3355 }
3356
3357 /*
3358  * LVM calls this function before a (read-only) snapshot is created.  This
3359  * gives us a chance to flush the journal completely and mark the fs clean.
3360  */
3361 static int ext4_freeze(struct super_block *sb)
3362 {
3363         int error = 0;
3364         journal_t *journal;
3365
3366         if (sb->s_flags & MS_RDONLY)
3367                 return 0;
3368
3369         journal = EXT4_SB(sb)->s_journal;
3370
3371         /* Now we set up the journal barrier. */
3372         jbd2_journal_lock_updates(journal);
3373
3374         /*
3375          * Don't clear the needs_recovery flag if we failed to flush
3376          * the journal.
3377          */
3378         error = jbd2_journal_flush(journal);
3379         if (error < 0) {
3380         out:
3381                 jbd2_journal_unlock_updates(journal);
3382                 return error;
3383         }
3384
3385         /* Journal blocked and flushed, clear needs_recovery flag. */
3386         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3387         error = ext4_commit_super(sb, 1);
3388         if (error)
3389                 goto out;
3390         return 0;
3391 }
3392
3393 /*
3394  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
3395  * flag here, even though the filesystem is not technically dirty yet.
3396  */
3397 static int ext4_unfreeze(struct super_block *sb)
3398 {
3399         if (sb->s_flags & MS_RDONLY)
3400                 return 0;
3401
3402         lock_super(sb);
3403         /* Reset the needs_recovery flag before the fs is unlocked. */
3404         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3405         ext4_commit_super(sb, 1);
3406         unlock_super(sb);
3407         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3408         return 0;
3409 }
3410
3411 static int ext4_remount(struct super_block *sb, int *flags, char *data)
3412 {
3413         struct ext4_super_block *es;
3414         struct ext4_sb_info *sbi = EXT4_SB(sb);
3415         ext4_fsblk_t n_blocks_count = 0;
3416         unsigned long old_sb_flags;
3417         struct ext4_mount_options old_opts;
3418         ext4_group_t g;
3419         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3420         int err;
3421 #ifdef CONFIG_QUOTA
3422         int i;
3423 #endif
3424
3425         lock_kernel();
3426
3427         /* Store the original options */
3428         lock_super(sb);
3429         old_sb_flags = sb->s_flags;
3430         old_opts.s_mount_opt = sbi->s_mount_opt;
3431         old_opts.s_resuid = sbi->s_resuid;
3432         old_opts.s_resgid = sbi->s_resgid;
3433         old_opts.s_commit_interval = sbi->s_commit_interval;
3434         old_opts.s_min_batch_time = sbi->s_min_batch_time;
3435         old_opts.s_max_batch_time = sbi->s_max_batch_time;
3436 #ifdef CONFIG_QUOTA
3437         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
3438         for (i = 0; i < MAXQUOTAS; i++)
3439                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
3440 #endif
3441         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
3442                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
3443
3444         /*
3445          * Allow the "check" option to be passed as a remount option.
3446          */
3447         if (!parse_options(data, sb, NULL, &journal_ioprio,
3448                            &n_blocks_count, 1)) {
3449                 err = -EINVAL;
3450                 goto restore_opts;
3451         }
3452
3453         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
3454                 ext4_abort(sb, __func__, "Abort forced by user");
3455
3456         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3457                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
3458
3459         es = sbi->s_es;
3460
3461         if (sbi->s_journal) {
3462                 ext4_init_journal_params(sb, sbi->s_journal);
3463                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3464         }
3465
3466         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
3467                 n_blocks_count > ext4_blocks_count(es)) {
3468                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
3469                         err = -EROFS;
3470                         goto restore_opts;
3471                 }
3472
3473                 if (*flags & MS_RDONLY) {
3474                         /*
3475                          * First of all, the unconditional stuff we have to do
3476                          * to disable replay of the journal when we next remount
3477                          */
3478                         sb->s_flags |= MS_RDONLY;
3479
3480                         /*
3481                          * OK, test if we are remounting a valid rw partition
3482                          * readonly, and if so set the rdonly flag and then
3483                          * mark the partition as valid again.
3484                          */
3485                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3486                             (sbi->s_mount_state & EXT4_VALID_FS))
3487                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
3488
3489                         if (sbi->s_journal)
3490                                 ext4_mark_recovery_complete(sb, es);
3491                 } else {
3492                         int ret;
3493                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3494                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
3495                                 ext4_msg(sb, KERN_WARNING, "couldn't "
3496                                        "remount RDWR because of unsupported "
3497                                        "optional features (%x)",
3498                                 (le32_to_cpu(sbi->s_es->s_feature_ro_compat) &
3499                                         ~EXT4_FEATURE_RO_COMPAT_SUPP));
3500                                 err = -EROFS;
3501                                 goto restore_opts;
3502                         }
3503
3504                         /*
3505                          * Make sure the group descriptor checksums
3506                          * are sane.  If they aren't, refuse to remount r/w.
3507                          */
3508                         for (g = 0; g < sbi->s_groups_count; g++) {
3509                                 struct ext4_group_desc *gdp =
3510                                         ext4_get_group_desc(sb, g, NULL);
3511
3512                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3513                                         ext4_msg(sb, KERN_ERR,
3514                "ext4_remount: Checksum for group %u failed (%u!=%u)",
3515                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3516                                                le16_to_cpu(gdp->bg_checksum));
3517                                         err = -EINVAL;
3518                                         goto restore_opts;
3519                                 }
3520                         }
3521
3522                         /*
3523                          * If we have an unprocessed orphan list hanging
3524                          * around from a previously readonly bdev mount,
3525                          * require a full umount/remount for now.
3526                          */
3527                         if (es->s_last_orphan) {
3528                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
3529                                        "remount RDWR because of unprocessed "
3530                                        "orphan inode list.  Please "
3531                                        "umount/remount instead");
3532                                 err = -EINVAL;
3533                                 goto restore_opts;
3534                         }
3535
3536                         /*
3537                          * Mounting a RDONLY partition read-write, so reread
3538                          * and store the current valid flag.  (It may have
3539                          * been changed by e2fsck since we originally mounted
3540                          * the partition.)
3541                          */
3542                         if (sbi->s_journal)
3543                                 ext4_clear_journal_err(sb, es);
3544                         sbi->s_mount_state = le16_to_cpu(es->s_state);
3545                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3546                                 goto restore_opts;
3547                         if (!ext4_setup_super(sb, es, 0))
3548                                 sb->s_flags &= ~MS_RDONLY;
3549                 }
3550         }
3551         ext4_setup_system_zone(sb);
3552         if (sbi->s_journal == NULL)
3553                 ext4_commit_super(sb, 1);
3554
3555 #ifdef CONFIG_QUOTA
3556         /* Release old quota file names */
3557         for (i = 0; i < MAXQUOTAS; i++)
3558                 if (old_opts.s_qf_names[i] &&
3559                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3560                         kfree(old_opts.s_qf_names[i]);
3561 #endif
3562         unlock_super(sb);
3563         unlock_kernel();
3564         return 0;
3565
3566 restore_opts:
3567         sb->s_flags = old_sb_flags;
3568         sbi->s_mount_opt = old_opts.s_mount_opt;
3569         sbi->s_resuid = old_opts.s_resuid;
3570         sbi->s_resgid = old_opts.s_resgid;
3571         sbi->s_commit_interval = old_opts.s_commit_interval;
3572         sbi->s_min_batch_time = old_opts.s_min_batch_time;
3573         sbi->s_max_batch_time = old_opts.s_max_batch_time;
3574 #ifdef CONFIG_QUOTA
3575         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3576         for (i = 0; i < MAXQUOTAS; i++) {
3577                 if (sbi->s_qf_names[i] &&
3578                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3579                         kfree(sbi->s_qf_names[i]);
3580                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3581         }
3582 #endif
3583         unlock_super(sb);
3584         unlock_kernel();
3585         return err;
3586 }
3587
3588 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
3589 {
3590         struct super_block *sb = dentry->d_sb;
3591         struct ext4_sb_info *sbi = EXT4_SB(sb);
3592         struct ext4_super_block *es = sbi->s_es;
3593         u64 fsid;
3594
3595         if (test_opt(sb, MINIX_DF)) {
3596                 sbi->s_overhead_last = 0;
3597         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3598                 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3599                 ext4_fsblk_t overhead = 0;
3600
3601                 /*
3602                  * Compute the overhead (FS structures).  This is constant
3603                  * for a given filesystem unless the number of block groups
3604                  * changes so we cache the previous value until it does.
3605                  */
3606
3607                 /*
3608                  * All of the blocks before first_data_block are
3609                  * overhead
3610                  */
3611                 overhead = le32_to_cpu(es->s_first_data_block);
3612
3613                 /*
3614                  * Add the overhead attributed to the superblock and
3615                  * block group descriptors.  If the sparse superblocks
3616                  * feature is turned on, then not all groups have this.
3617                  */
3618                 for (i = 0; i < ngroups; i++) {
3619                         overhead += ext4_bg_has_super(sb, i) +
3620                                 ext4_bg_num_gdb(sb, i);
3621                         cond_resched();
3622                 }
3623
3624                 /*
3625                  * Every block group has an inode bitmap, a block
3626                  * bitmap, and an inode table.
3627                  */
3628                 overhead += ngroups * (2 + sbi->s_itb_per_group);
3629                 sbi->s_overhead_last = overhead;
3630                 smp_wmb();
3631                 sbi->s_blocks_last = ext4_blocks_count(es);
3632         }
3633
3634         buf->f_type = EXT4_SUPER_MAGIC;
3635         buf->f_bsize = sb->s_blocksize;
3636         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3637         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
3638                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
3639         ext4_free_blocks_count_set(es, buf->f_bfree);
3640         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3641         if (buf->f_bfree < ext4_r_blocks_count(es))
3642                 buf->f_bavail = 0;
3643         buf->f_files = le32_to_cpu(es->s_inodes_count);
3644         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3645         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
3646         buf->f_namelen = EXT4_NAME_LEN;
3647         fsid = le64_to_cpup((void *)es->s_uuid) ^
3648                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3649         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3650         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3651
3652         return 0;
3653 }
3654
3655 /* Helper function for writing quotas on sync - we need to start transaction
3656  * before quota file is locked for write. Otherwise the are possible deadlocks:
3657  * Process 1                         Process 2
3658  * ext4_create()                     quota_sync()
3659  *   jbd2_journal_start()                  write_dquot()
3660  *   vfs_dq_init()                         down(dqio_mutex)
3661  *     down(dqio_mutex)                    jbd2_journal_start()
3662  *
3663  */
3664
3665 #ifdef CONFIG_QUOTA
3666
3667 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3668 {
3669         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3670 }
3671
3672 static int ext4_write_dquot(struct dquot *dquot)
3673 {
3674         int ret, err;
3675         handle_t *handle;
3676         struct inode *inode;
3677
3678         inode = dquot_to_inode(dquot);
3679         handle = ext4_journal_start(inode,
3680                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3681         if (IS_ERR(handle))
3682                 return PTR_ERR(handle);
3683         ret = dquot_commit(dquot);
3684         err = ext4_journal_stop(handle);
3685         if (!ret)
3686                 ret = err;
3687         return ret;
3688 }
3689
3690 static int ext4_acquire_dquot(struct dquot *dquot)
3691 {
3692         int ret, err;
3693         handle_t *handle;
3694
3695         handle = ext4_journal_start(dquot_to_inode(dquot),
3696                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3697         if (IS_ERR(handle))
3698                 return PTR_ERR(handle);
3699         ret = dquot_acquire(dquot);
3700         err = ext4_journal_stop(handle);
3701         if (!ret)
3702                 ret = err;
3703         return ret;
3704 }
3705
3706 static int ext4_release_dquot(struct dquot *dquot)
3707 {
3708         int ret, err;
3709         handle_t *handle;
3710
3711         handle = ext4_journal_start(dquot_to_inode(dquot),
3712                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3713         if (IS_ERR(handle)) {
3714                 /* Release dquot anyway to avoid endless cycle in dqput() */
3715                 dquot_release(dquot);
3716                 return PTR_ERR(handle);
3717         }
3718         ret = dquot_release(dquot);
3719         err = ext4_journal_stop(handle);
3720         if (!ret)
3721                 ret = err;
3722         return ret;
3723 }
3724
3725 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3726 {
3727         /* Are we journaling quotas? */
3728         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3729             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3730                 dquot_mark_dquot_dirty(dquot);
3731                 return ext4_write_dquot(dquot);
3732         } else {
3733                 return dquot_mark_dquot_dirty(dquot);
3734         }
3735 }
3736
3737 static int ext4_write_info(struct super_block *sb, int type)
3738 {
3739         int ret, err;
3740         handle_t *handle;
3741
3742         /* Data block + inode block */
3743         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3744         if (IS_ERR(handle))
3745                 return PTR_ERR(handle);
3746         ret = dquot_commit_info(sb, type);
3747         err = ext4_journal_stop(handle);
3748         if (!ret)
3749                 ret = err;
3750         return ret;
3751 }
3752
3753 /*
3754  * Turn on quotas during mount time - we need to find
3755  * the quota file and such...
3756  */
3757 static int ext4_quota_on_mount(struct super_block *sb, int type)
3758 {
3759         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3760                                   EXT4_SB(sb)->s_jquota_fmt, type);
3761 }
3762
3763 /*
3764  * Standard function to be called on quota_on
3765  */
3766 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3767                          char *name, int remount)
3768 {
3769         int err;
3770         struct path path;
3771
3772         if (!test_opt(sb, QUOTA))
3773                 return -EINVAL;
3774         /* When remounting, no checks are needed and in fact, name is NULL */
3775         if (remount)
3776                 return vfs_quota_on(sb, type, format_id, name, remount);
3777
3778         err = kern_path(name, LOOKUP_FOLLOW, &path);
3779         if (err)
3780                 return err;
3781
3782         /* Quotafile not on the same filesystem? */
3783         if (path.mnt->mnt_sb != sb) {
3784                 path_put(&path);
3785                 return -EXDEV;
3786         }
3787         /* Journaling quota? */
3788         if (EXT4_SB(sb)->s_qf_names[type]) {
3789                 /* Quotafile not in fs root? */
3790                 if (path.dentry->d_parent != sb->s_root)
3791                         ext4_msg(sb, KERN_WARNING,
3792                                 "Quota file not on filesystem root. "
3793                                 "Journaled quota will not work");
3794         }
3795
3796         /*
3797          * When we journal data on quota file, we have to flush journal to see
3798          * all updates to the file when we bypass pagecache...
3799          */
3800         if (EXT4_SB(sb)->s_journal &&
3801             ext4_should_journal_data(path.dentry->d_inode)) {
3802                 /*
3803                  * We don't need to lock updates but journal_flush() could
3804                  * otherwise be livelocked...
3805                  */
3806                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3807                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3808                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3809                 if (err) {
3810                         path_put(&path);
3811                         return err;
3812                 }
3813         }
3814
3815         err = vfs_quota_on_path(sb, type, format_id, &path);
3816         path_put(&path);
3817         return err;
3818 }
3819
3820 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3821  * acquiring the locks... As quota files are never truncated and quota code
3822  * itself serializes the operations (and noone else should touch the files)
3823  * we don't have to be afraid of races */
3824 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3825                                size_t len, loff_t off)
3826 {
3827         struct inode *inode = sb_dqopt(sb)->files[type];
3828         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3829         int err = 0;
3830         int offset = off & (sb->s_blocksize - 1);
3831         int tocopy;
3832         size_t toread;
3833         struct buffer_head *bh;
3834         loff_t i_size = i_size_read(inode);
3835
3836         if (off > i_size)
3837                 return 0;
3838         if (off+len > i_size)
3839                 len = i_size-off;
3840         toread = len;
3841         while (toread > 0) {
3842                 tocopy = sb->s_blocksize - offset < toread ?
3843                                 sb->s_blocksize - offset : toread;
3844                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3845                 if (err)
3846                         return err;
3847                 if (!bh)        /* A hole? */
3848                         memset(data, 0, tocopy);
3849                 else
3850                         memcpy(data, bh->b_data+offset, tocopy);
3851                 brelse(bh);
3852                 offset = 0;
3853                 toread -= tocopy;
3854                 data += tocopy;
3855                 blk++;
3856         }
3857         return len;
3858 }
3859
3860 /* Write to quotafile (we know the transaction is already started and has
3861  * enough credits) */
3862 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3863                                 const char *data, size_t len, loff_t off)
3864 {
3865         struct inode *inode = sb_dqopt(sb)->files[type];
3866         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3867         int err = 0;
3868         int offset = off & (sb->s_blocksize - 1);
3869         int tocopy;
3870         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3871         size_t towrite = len;
3872         struct buffer_head *bh;
3873         handle_t *handle = journal_current_handle();
3874
3875         if (EXT4_SB(sb)->s_journal && !handle) {
3876                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
3877                         " cancelled because transaction is not started",
3878                         (unsigned long long)off, (unsigned long long)len);
3879                 return -EIO;
3880         }
3881         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3882         while (towrite > 0) {
3883                 tocopy = sb->s_blocksize - offset < towrite ?
3884                                 sb->s_blocksize - offset : towrite;
3885                 bh = ext4_bread(handle, inode, blk, 1, &err);
3886                 if (!bh)
3887                         goto out;
3888                 if (journal_quota) {
3889                         err = ext4_journal_get_write_access(handle, bh);
3890                         if (err) {
3891                                 brelse(bh);
3892                                 goto out;
3893                         }
3894                 }
3895                 lock_buffer(bh);
3896                 memcpy(bh->b_data+offset, data, tocopy);
3897                 flush_dcache_page(bh->b_page);
3898                 unlock_buffer(bh);
3899                 if (journal_quota)
3900                         err = ext4_handle_dirty_metadata(handle, NULL, bh);
3901                 else {
3902                         /* Always do at least ordered writes for quotas */
3903                         err = ext4_jbd2_file_inode(handle, inode);
3904                         mark_buffer_dirty(bh);
3905                 }
3906                 brelse(bh);
3907                 if (err)
3908                         goto out;
3909                 offset = 0;
3910                 towrite -= tocopy;
3911                 data += tocopy;
3912                 blk++;
3913         }
3914 out:
3915         if (len == towrite) {
3916                 mutex_unlock(&inode->i_mutex);
3917                 return err;
3918         }
3919         if (inode->i_size < off+len-towrite) {
3920                 i_size_write(inode, off+len-towrite);
3921                 EXT4_I(inode)->i_disksize = inode->i_size;
3922         }
3923         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3924         ext4_mark_inode_dirty(handle, inode);
3925         mutex_unlock(&inode->i_mutex);
3926         return len - towrite;
3927 }
3928
3929 #endif
3930
3931 static int ext4_get_sb(struct file_system_type *fs_type, int flags,
3932                        const char *dev_name, void *data, struct vfsmount *mnt)
3933 {
3934         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super,mnt);
3935 }
3936
3937 static struct file_system_type ext4_fs_type = {
3938         .owner          = THIS_MODULE,
3939         .name           = "ext4",
3940         .get_sb         = ext4_get_sb,
3941         .kill_sb        = kill_block_super,
3942         .fs_flags       = FS_REQUIRES_DEV,
3943 };
3944
3945 #ifdef CONFIG_EXT4DEV_COMPAT
3946 static int ext4dev_get_sb(struct file_system_type *fs_type, int flags,
3947                           const char *dev_name, void *data,struct vfsmount *mnt)
3948 {
3949         printk(KERN_WARNING "EXT4-fs (%s): Update your userspace programs "
3950                "to mount using ext4\n", dev_name);
3951         printk(KERN_WARNING "EXT4-fs (%s): ext4dev backwards compatibility "
3952                "will go away by 2.6.31\n", dev_name);
3953         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super,mnt);
3954 }
3955
3956 static struct file_system_type ext4dev_fs_type = {
3957         .owner          = THIS_MODULE,
3958         .name           = "ext4dev",
3959         .get_sb         = ext4dev_get_sb,
3960         .kill_sb        = kill_block_super,
3961         .fs_flags       = FS_REQUIRES_DEV,
3962 };
3963 MODULE_ALIAS("ext4dev");
3964 #endif
3965
3966 static int __init init_ext4_fs(void)
3967 {
3968         int err;
3969
3970         err = init_ext4_system_zone();
3971         if (err)
3972                 return err;
3973         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
3974         if (!ext4_kset)
3975                 goto out4;
3976         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
3977         err = init_ext4_mballoc();
3978         if (err)
3979                 goto out3;
3980
3981         err = init_ext4_xattr();
3982         if (err)
3983                 goto out2;
3984         err = init_inodecache();
3985         if (err)
3986                 goto out1;
3987         err = register_filesystem(&ext4_fs_type);
3988         if (err)
3989                 goto out;
3990 #ifdef CONFIG_EXT4DEV_COMPAT
3991         err = register_filesystem(&ext4dev_fs_type);
3992         if (err) {
3993                 unregister_filesystem(&ext4_fs_type);
3994                 goto out;
3995         }
3996 #endif
3997         return 0;
3998 out:
3999         destroy_inodecache();
4000 out1:
4001         exit_ext4_xattr();
4002 out2:
4003         exit_ext4_mballoc();
4004 out3:
4005         remove_proc_entry("fs/ext4", NULL);
4006         kset_unregister(ext4_kset);
4007 out4:
4008         exit_ext4_system_zone();
4009         return err;
4010 }
4011
4012 static void __exit exit_ext4_fs(void)
4013 {
4014         unregister_filesystem(&ext4_fs_type);
4015 #ifdef CONFIG_EXT4DEV_COMPAT
4016         unregister_filesystem(&ext4dev_fs_type);
4017 #endif
4018         destroy_inodecache();
4019         exit_ext4_xattr();
4020         exit_ext4_mballoc();
4021         remove_proc_entry("fs/ext4", NULL);
4022         kset_unregister(ext4_kset);
4023         exit_ext4_system_zone();
4024 }
4025
4026 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
4027 MODULE_DESCRIPTION("Fourth Extended Filesystem");
4028 MODULE_LICENSE("GPL");
4029 module_init(init_ext4_fs)
4030 module_exit(exit_ext4_fs)