mm: Remove slab destructors from kmem_cache_create().
[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/jbd2.h>
24 #include <linux/ext4_fs.h>
25 #include <linux/ext4_jbd2.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/blkdev.h>
29 #include <linux/parser.h>
30 #include <linux/smp_lock.h>
31 #include <linux/buffer_head.h>
32 #include <linux/exportfs.h>
33 #include <linux/vfs.h>
34 #include <linux/random.h>
35 #include <linux/mount.h>
36 #include <linux/namei.h>
37 #include <linux/quotaops.h>
38 #include <linux/seq_file.h>
39 #include <linux/log2.h>
40
41 #include <asm/uaccess.h>
42
43 #include "xattr.h"
44 #include "acl.h"
45 #include "namei.h"
46
47 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
48                              unsigned long journal_devnum);
49 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
50                                unsigned int);
51 static void ext4_commit_super (struct super_block * sb,
52                                struct ext4_super_block * es,
53                                int sync);
54 static void ext4_mark_recovery_complete(struct super_block * sb,
55                                         struct ext4_super_block * es);
56 static void ext4_clear_journal_err(struct super_block * sb,
57                                    struct ext4_super_block * es);
58 static int ext4_sync_fs(struct super_block *sb, int wait);
59 static const char *ext4_decode_error(struct super_block * sb, int errno,
60                                      char nbuf[16]);
61 static int ext4_remount (struct super_block * sb, int * flags, char * data);
62 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
63 static void ext4_unlockfs(struct super_block *sb);
64 static void ext4_write_super (struct super_block * sb);
65 static void ext4_write_super_lockfs(struct super_block *sb);
66
67
68 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
69                                struct ext4_group_desc *bg)
70 {
71         return le32_to_cpu(bg->bg_block_bitmap) |
72                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
73                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
74 }
75
76 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
77                                struct ext4_group_desc *bg)
78 {
79         return le32_to_cpu(bg->bg_inode_bitmap) |
80                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
81                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
82 }
83
84 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
85                               struct ext4_group_desc *bg)
86 {
87         return le32_to_cpu(bg->bg_inode_table) |
88                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
89                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
90 }
91
92 void ext4_block_bitmap_set(struct super_block *sb,
93                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
94 {
95         bg->bg_block_bitmap = cpu_to_le32((u32)blk);
96         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
97                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
98 }
99
100 void ext4_inode_bitmap_set(struct super_block *sb,
101                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
102 {
103         bg->bg_inode_bitmap  = cpu_to_le32((u32)blk);
104         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
105                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
106 }
107
108 void ext4_inode_table_set(struct super_block *sb,
109                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
110 {
111         bg->bg_inode_table = cpu_to_le32((u32)blk);
112         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
113                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
114 }
115
116 /*
117  * Wrappers for jbd2_journal_start/end.
118  *
119  * The only special thing we need to do here is to make sure that all
120  * journal_end calls result in the superblock being marked dirty, so
121  * that sync() will call the filesystem's write_super callback if
122  * appropriate.
123  */
124 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
125 {
126         journal_t *journal;
127
128         if (sb->s_flags & MS_RDONLY)
129                 return ERR_PTR(-EROFS);
130
131         /* Special case here: if the journal has aborted behind our
132          * backs (eg. EIO in the commit thread), then we still need to
133          * take the FS itself readonly cleanly. */
134         journal = EXT4_SB(sb)->s_journal;
135         if (is_journal_aborted(journal)) {
136                 ext4_abort(sb, __FUNCTION__,
137                            "Detected aborted journal");
138                 return ERR_PTR(-EROFS);
139         }
140
141         return jbd2_journal_start(journal, nblocks);
142 }
143
144 /*
145  * The only special thing we need to do here is to make sure that all
146  * jbd2_journal_stop calls result in the superblock being marked dirty, so
147  * that sync() will call the filesystem's write_super callback if
148  * appropriate.
149  */
150 int __ext4_journal_stop(const char *where, handle_t *handle)
151 {
152         struct super_block *sb;
153         int err;
154         int rc;
155
156         sb = handle->h_transaction->t_journal->j_private;
157         err = handle->h_err;
158         rc = jbd2_journal_stop(handle);
159
160         if (!err)
161                 err = rc;
162         if (err)
163                 __ext4_std_error(sb, where, err);
164         return err;
165 }
166
167 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
168                 struct buffer_head *bh, handle_t *handle, int err)
169 {
170         char nbuf[16];
171         const char *errstr = ext4_decode_error(NULL, err, nbuf);
172
173         if (bh)
174                 BUFFER_TRACE(bh, "abort");
175
176         if (!handle->h_err)
177                 handle->h_err = err;
178
179         if (is_handle_aborted(handle))
180                 return;
181
182         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
183                caller, errstr, err_fn);
184
185         jbd2_journal_abort_handle(handle);
186 }
187
188 /* Deal with the reporting of failure conditions on a filesystem such as
189  * inconsistencies detected or read IO failures.
190  *
191  * On ext2, we can store the error state of the filesystem in the
192  * superblock.  That is not possible on ext4, because we may have other
193  * write ordering constraints on the superblock which prevent us from
194  * writing it out straight away; and given that the journal is about to
195  * be aborted, we can't rely on the current, or future, transactions to
196  * write out the superblock safely.
197  *
198  * We'll just use the jbd2_journal_abort() error code to record an error in
199  * the journal instead.  On recovery, the journal will compain about
200  * that error until we've noted it down and cleared it.
201  */
202
203 static void ext4_handle_error(struct super_block *sb)
204 {
205         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
206
207         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
208         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
209
210         if (sb->s_flags & MS_RDONLY)
211                 return;
212
213         if (!test_opt (sb, ERRORS_CONT)) {
214                 journal_t *journal = EXT4_SB(sb)->s_journal;
215
216                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
217                 if (journal)
218                         jbd2_journal_abort(journal, -EIO);
219         }
220         if (test_opt (sb, ERRORS_RO)) {
221                 printk (KERN_CRIT "Remounting filesystem read-only\n");
222                 sb->s_flags |= MS_RDONLY;
223         }
224         ext4_commit_super(sb, es, 1);
225         if (test_opt(sb, ERRORS_PANIC))
226                 panic("EXT4-fs (device %s): panic forced after error\n",
227                         sb->s_id);
228 }
229
230 void ext4_error (struct super_block * sb, const char * function,
231                  const char * fmt, ...)
232 {
233         va_list args;
234
235         va_start(args, fmt);
236         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
237         vprintk(fmt, args);
238         printk("\n");
239         va_end(args);
240
241         ext4_handle_error(sb);
242 }
243
244 static const char *ext4_decode_error(struct super_block * sb, int errno,
245                                      char nbuf[16])
246 {
247         char *errstr = NULL;
248
249         switch (errno) {
250         case -EIO:
251                 errstr = "IO failure";
252                 break;
253         case -ENOMEM:
254                 errstr = "Out of memory";
255                 break;
256         case -EROFS:
257                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
258                         errstr = "Journal has aborted";
259                 else
260                         errstr = "Readonly filesystem";
261                 break;
262         default:
263                 /* If the caller passed in an extra buffer for unknown
264                  * errors, textualise them now.  Else we just return
265                  * NULL. */
266                 if (nbuf) {
267                         /* Check for truncated error codes... */
268                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
269                                 errstr = nbuf;
270                 }
271                 break;
272         }
273
274         return errstr;
275 }
276
277 /* __ext4_std_error decodes expected errors from journaling functions
278  * automatically and invokes the appropriate error response.  */
279
280 void __ext4_std_error (struct super_block * sb, const char * function,
281                        int errno)
282 {
283         char nbuf[16];
284         const char *errstr;
285
286         /* Special case: if the error is EROFS, and we're not already
287          * inside a transaction, then there's really no point in logging
288          * an error. */
289         if (errno == -EROFS && journal_current_handle() == NULL &&
290             (sb->s_flags & MS_RDONLY))
291                 return;
292
293         errstr = ext4_decode_error(sb, errno, nbuf);
294         printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
295                 sb->s_id, function, errstr);
296
297         ext4_handle_error(sb);
298 }
299
300 /*
301  * ext4_abort is a much stronger failure handler than ext4_error.  The
302  * abort function may be used to deal with unrecoverable failures such
303  * as journal IO errors or ENOMEM at a critical moment in log management.
304  *
305  * We unconditionally force the filesystem into an ABORT|READONLY state,
306  * unless the error response on the fs has been set to panic in which
307  * case we take the easy way out and panic immediately.
308  */
309
310 void ext4_abort (struct super_block * sb, const char * function,
311                  const char * fmt, ...)
312 {
313         va_list args;
314
315         printk (KERN_CRIT "ext4_abort called.\n");
316
317         va_start(args, fmt);
318         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
319         vprintk(fmt, args);
320         printk("\n");
321         va_end(args);
322
323         if (test_opt(sb, ERRORS_PANIC))
324                 panic("EXT4-fs panic from previous error\n");
325
326         if (sb->s_flags & MS_RDONLY)
327                 return;
328
329         printk(KERN_CRIT "Remounting filesystem read-only\n");
330         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
331         sb->s_flags |= MS_RDONLY;
332         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
333         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
334 }
335
336 void ext4_warning (struct super_block * sb, const char * function,
337                    const char * fmt, ...)
338 {
339         va_list args;
340
341         va_start(args, fmt);
342         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
343                sb->s_id, function);
344         vprintk(fmt, args);
345         printk("\n");
346         va_end(args);
347 }
348
349 void ext4_update_dynamic_rev(struct super_block *sb)
350 {
351         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
352
353         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
354                 return;
355
356         ext4_warning(sb, __FUNCTION__,
357                      "updating to rev %d because of new feature flag, "
358                      "running e2fsck is recommended",
359                      EXT4_DYNAMIC_REV);
360
361         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
362         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
363         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
364         /* leave es->s_feature_*compat flags alone */
365         /* es->s_uuid will be set by e2fsck if empty */
366
367         /*
368          * The rest of the superblock fields should be zero, and if not it
369          * means they are likely already in use, so leave them alone.  We
370          * can leave it up to e2fsck to clean up any inconsistencies there.
371          */
372 }
373
374 /*
375  * Open the external journal device
376  */
377 static struct block_device *ext4_blkdev_get(dev_t dev)
378 {
379         struct block_device *bdev;
380         char b[BDEVNAME_SIZE];
381
382         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
383         if (IS_ERR(bdev))
384                 goto fail;
385         return bdev;
386
387 fail:
388         printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
389                         __bdevname(dev, b), PTR_ERR(bdev));
390         return NULL;
391 }
392
393 /*
394  * Release the journal device
395  */
396 static int ext4_blkdev_put(struct block_device *bdev)
397 {
398         bd_release(bdev);
399         return blkdev_put(bdev);
400 }
401
402 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
403 {
404         struct block_device *bdev;
405         int ret = -ENODEV;
406
407         bdev = sbi->journal_bdev;
408         if (bdev) {
409                 ret = ext4_blkdev_put(bdev);
410                 sbi->journal_bdev = NULL;
411         }
412         return ret;
413 }
414
415 static inline struct inode *orphan_list_entry(struct list_head *l)
416 {
417         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
418 }
419
420 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
421 {
422         struct list_head *l;
423
424         printk(KERN_ERR "sb orphan head is %d\n",
425                le32_to_cpu(sbi->s_es->s_last_orphan));
426
427         printk(KERN_ERR "sb_info orphan list:\n");
428         list_for_each(l, &sbi->s_orphan) {
429                 struct inode *inode = orphan_list_entry(l);
430                 printk(KERN_ERR "  "
431                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
432                        inode->i_sb->s_id, inode->i_ino, inode,
433                        inode->i_mode, inode->i_nlink,
434                        NEXT_ORPHAN(inode));
435         }
436 }
437
438 static void ext4_put_super (struct super_block * sb)
439 {
440         struct ext4_sb_info *sbi = EXT4_SB(sb);
441         struct ext4_super_block *es = sbi->s_es;
442         int i;
443
444         ext4_ext_release(sb);
445         ext4_xattr_put_super(sb);
446         jbd2_journal_destroy(sbi->s_journal);
447         if (!(sb->s_flags & MS_RDONLY)) {
448                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
449                 es->s_state = cpu_to_le16(sbi->s_mount_state);
450                 BUFFER_TRACE(sbi->s_sbh, "marking dirty");
451                 mark_buffer_dirty(sbi->s_sbh);
452                 ext4_commit_super(sb, es, 1);
453         }
454
455         for (i = 0; i < sbi->s_gdb_count; i++)
456                 brelse(sbi->s_group_desc[i]);
457         kfree(sbi->s_group_desc);
458         percpu_counter_destroy(&sbi->s_freeblocks_counter);
459         percpu_counter_destroy(&sbi->s_freeinodes_counter);
460         percpu_counter_destroy(&sbi->s_dirs_counter);
461         brelse(sbi->s_sbh);
462 #ifdef CONFIG_QUOTA
463         for (i = 0; i < MAXQUOTAS; i++)
464                 kfree(sbi->s_qf_names[i]);
465 #endif
466
467         /* Debugging code just in case the in-memory inode orphan list
468          * isn't empty.  The on-disk one can be non-empty if we've
469          * detected an error and taken the fs readonly, but the
470          * in-memory list had better be clean by this point. */
471         if (!list_empty(&sbi->s_orphan))
472                 dump_orphan_list(sb, sbi);
473         J_ASSERT(list_empty(&sbi->s_orphan));
474
475         invalidate_bdev(sb->s_bdev);
476         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
477                 /*
478                  * Invalidate the journal device's buffers.  We don't want them
479                  * floating about in memory - the physical journal device may
480                  * hotswapped, and it breaks the `ro-after' testing code.
481                  */
482                 sync_blockdev(sbi->journal_bdev);
483                 invalidate_bdev(sbi->journal_bdev);
484                 ext4_blkdev_remove(sbi);
485         }
486         sb->s_fs_info = NULL;
487         kfree(sbi);
488         return;
489 }
490
491 static struct kmem_cache *ext4_inode_cachep;
492
493 /*
494  * Called inside transaction, so use GFP_NOFS
495  */
496 static struct inode *ext4_alloc_inode(struct super_block *sb)
497 {
498         struct ext4_inode_info *ei;
499
500         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
501         if (!ei)
502                 return NULL;
503 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
504         ei->i_acl = EXT4_ACL_NOT_CACHED;
505         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
506 #endif
507         ei->i_block_alloc_info = NULL;
508         ei->vfs_inode.i_version = 1;
509         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
510         return &ei->vfs_inode;
511 }
512
513 static void ext4_destroy_inode(struct inode *inode)
514 {
515         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
516                 printk("EXT4 Inode %p: orphan list check failed!\n",
517                         EXT4_I(inode));
518                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
519                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
520                                 true);
521                 dump_stack();
522         }
523         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
524 }
525
526 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
527 {
528         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
529
530         INIT_LIST_HEAD(&ei->i_orphan);
531 #ifdef CONFIG_EXT4DEV_FS_XATTR
532         init_rwsem(&ei->xattr_sem);
533 #endif
534         mutex_init(&ei->truncate_mutex);
535         inode_init_once(&ei->vfs_inode);
536 }
537
538 static int init_inodecache(void)
539 {
540         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
541                                              sizeof(struct ext4_inode_info),
542                                              0, (SLAB_RECLAIM_ACCOUNT|
543                                                 SLAB_MEM_SPREAD),
544                                              init_once);
545         if (ext4_inode_cachep == NULL)
546                 return -ENOMEM;
547         return 0;
548 }
549
550 static void destroy_inodecache(void)
551 {
552         kmem_cache_destroy(ext4_inode_cachep);
553 }
554
555 static void ext4_clear_inode(struct inode *inode)
556 {
557         struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
558 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
559         if (EXT4_I(inode)->i_acl &&
560                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
561                 posix_acl_release(EXT4_I(inode)->i_acl);
562                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
563         }
564         if (EXT4_I(inode)->i_default_acl &&
565                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
566                 posix_acl_release(EXT4_I(inode)->i_default_acl);
567                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
568         }
569 #endif
570         ext4_discard_reservation(inode);
571         EXT4_I(inode)->i_block_alloc_info = NULL;
572         if (unlikely(rsv))
573                 kfree(rsv);
574 }
575
576 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
577 {
578 #if defined(CONFIG_QUOTA)
579         struct ext4_sb_info *sbi = EXT4_SB(sb);
580
581         if (sbi->s_jquota_fmt)
582                 seq_printf(seq, ",jqfmt=%s",
583                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
584
585         if (sbi->s_qf_names[USRQUOTA])
586                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
587
588         if (sbi->s_qf_names[GRPQUOTA])
589                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
590
591         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
592                 seq_puts(seq, ",usrquota");
593
594         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
595                 seq_puts(seq, ",grpquota");
596 #endif
597 }
598
599 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
600 {
601         struct super_block *sb = vfs->mnt_sb;
602
603         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
604                 seq_puts(seq, ",data=journal");
605         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
606                 seq_puts(seq, ",data=ordered");
607         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
608                 seq_puts(seq, ",data=writeback");
609
610         ext4_show_quota_options(seq, sb);
611
612         return 0;
613 }
614
615
616 static struct dentry *ext4_get_dentry(struct super_block *sb, void *vobjp)
617 {
618         __u32 *objp = vobjp;
619         unsigned long ino = objp[0];
620         __u32 generation = objp[1];
621         struct inode *inode;
622         struct dentry *result;
623
624         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
625                 return ERR_PTR(-ESTALE);
626         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
627                 return ERR_PTR(-ESTALE);
628
629         /* iget isn't really right if the inode is currently unallocated!!
630          *
631          * ext4_read_inode will return a bad_inode if the inode had been
632          * deleted, so we should be safe.
633          *
634          * Currently we don't know the generation for parent directory, so
635          * a generation of 0 means "accept any"
636          */
637         inode = iget(sb, ino);
638         if (inode == NULL)
639                 return ERR_PTR(-ENOMEM);
640         if (is_bad_inode(inode) ||
641             (generation && inode->i_generation != generation)) {
642                 iput(inode);
643                 return ERR_PTR(-ESTALE);
644         }
645         /* now to find a dentry.
646          * If possible, get a well-connected one
647          */
648         result = d_alloc_anon(inode);
649         if (!result) {
650                 iput(inode);
651                 return ERR_PTR(-ENOMEM);
652         }
653         return result;
654 }
655
656 #ifdef CONFIG_QUOTA
657 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
658 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
659
660 static int ext4_dquot_initialize(struct inode *inode, int type);
661 static int ext4_dquot_drop(struct inode *inode);
662 static int ext4_write_dquot(struct dquot *dquot);
663 static int ext4_acquire_dquot(struct dquot *dquot);
664 static int ext4_release_dquot(struct dquot *dquot);
665 static int ext4_mark_dquot_dirty(struct dquot *dquot);
666 static int ext4_write_info(struct super_block *sb, int type);
667 static int ext4_quota_on(struct super_block *sb, int type, int format_id, char *path);
668 static int ext4_quota_on_mount(struct super_block *sb, int type);
669 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
670                                size_t len, loff_t off);
671 static ssize_t ext4_quota_write(struct super_block *sb, int type,
672                                 const char *data, size_t len, loff_t off);
673
674 static struct dquot_operations ext4_quota_operations = {
675         .initialize     = ext4_dquot_initialize,
676         .drop           = ext4_dquot_drop,
677         .alloc_space    = dquot_alloc_space,
678         .alloc_inode    = dquot_alloc_inode,
679         .free_space     = dquot_free_space,
680         .free_inode     = dquot_free_inode,
681         .transfer       = dquot_transfer,
682         .write_dquot    = ext4_write_dquot,
683         .acquire_dquot  = ext4_acquire_dquot,
684         .release_dquot  = ext4_release_dquot,
685         .mark_dirty     = ext4_mark_dquot_dirty,
686         .write_info     = ext4_write_info
687 };
688
689 static struct quotactl_ops ext4_qctl_operations = {
690         .quota_on       = ext4_quota_on,
691         .quota_off      = vfs_quota_off,
692         .quota_sync     = vfs_quota_sync,
693         .get_info       = vfs_get_dqinfo,
694         .set_info       = vfs_set_dqinfo,
695         .get_dqblk      = vfs_get_dqblk,
696         .set_dqblk      = vfs_set_dqblk
697 };
698 #endif
699
700 static const struct super_operations ext4_sops = {
701         .alloc_inode    = ext4_alloc_inode,
702         .destroy_inode  = ext4_destroy_inode,
703         .read_inode     = ext4_read_inode,
704         .write_inode    = ext4_write_inode,
705         .dirty_inode    = ext4_dirty_inode,
706         .delete_inode   = ext4_delete_inode,
707         .put_super      = ext4_put_super,
708         .write_super    = ext4_write_super,
709         .sync_fs        = ext4_sync_fs,
710         .write_super_lockfs = ext4_write_super_lockfs,
711         .unlockfs       = ext4_unlockfs,
712         .statfs         = ext4_statfs,
713         .remount_fs     = ext4_remount,
714         .clear_inode    = ext4_clear_inode,
715         .show_options   = ext4_show_options,
716 #ifdef CONFIG_QUOTA
717         .quota_read     = ext4_quota_read,
718         .quota_write    = ext4_quota_write,
719 #endif
720 };
721
722 static struct export_operations ext4_export_ops = {
723         .get_parent = ext4_get_parent,
724         .get_dentry = ext4_get_dentry,
725 };
726
727 enum {
728         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
729         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
730         Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
731         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
732         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
733         Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
734         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
735         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
736         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
737         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
738         Opt_grpquota, Opt_extents, Opt_noextents,
739 };
740
741 static match_table_t tokens = {
742         {Opt_bsd_df, "bsddf"},
743         {Opt_minix_df, "minixdf"},
744         {Opt_grpid, "grpid"},
745         {Opt_grpid, "bsdgroups"},
746         {Opt_nogrpid, "nogrpid"},
747         {Opt_nogrpid, "sysvgroups"},
748         {Opt_resgid, "resgid=%u"},
749         {Opt_resuid, "resuid=%u"},
750         {Opt_sb, "sb=%u"},
751         {Opt_err_cont, "errors=continue"},
752         {Opt_err_panic, "errors=panic"},
753         {Opt_err_ro, "errors=remount-ro"},
754         {Opt_nouid32, "nouid32"},
755         {Opt_nocheck, "nocheck"},
756         {Opt_nocheck, "check=none"},
757         {Opt_debug, "debug"},
758         {Opt_oldalloc, "oldalloc"},
759         {Opt_orlov, "orlov"},
760         {Opt_user_xattr, "user_xattr"},
761         {Opt_nouser_xattr, "nouser_xattr"},
762         {Opt_acl, "acl"},
763         {Opt_noacl, "noacl"},
764         {Opt_reservation, "reservation"},
765         {Opt_noreservation, "noreservation"},
766         {Opt_noload, "noload"},
767         {Opt_nobh, "nobh"},
768         {Opt_bh, "bh"},
769         {Opt_commit, "commit=%u"},
770         {Opt_journal_update, "journal=update"},
771         {Opt_journal_inum, "journal=%u"},
772         {Opt_journal_dev, "journal_dev=%u"},
773         {Opt_abort, "abort"},
774         {Opt_data_journal, "data=journal"},
775         {Opt_data_ordered, "data=ordered"},
776         {Opt_data_writeback, "data=writeback"},
777         {Opt_offusrjquota, "usrjquota="},
778         {Opt_usrjquota, "usrjquota=%s"},
779         {Opt_offgrpjquota, "grpjquota="},
780         {Opt_grpjquota, "grpjquota=%s"},
781         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
782         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
783         {Opt_grpquota, "grpquota"},
784         {Opt_noquota, "noquota"},
785         {Opt_quota, "quota"},
786         {Opt_usrquota, "usrquota"},
787         {Opt_barrier, "barrier=%u"},
788         {Opt_extents, "extents"},
789         {Opt_noextents, "noextents"},
790         {Opt_err, NULL},
791         {Opt_resize, "resize"},
792 };
793
794 static ext4_fsblk_t get_sb_block(void **data)
795 {
796         ext4_fsblk_t    sb_block;
797         char            *options = (char *) *data;
798
799         if (!options || strncmp(options, "sb=", 3) != 0)
800                 return 1;       /* Default location */
801         options += 3;
802         /*todo: use simple_strtoll with >32bit ext4 */
803         sb_block = simple_strtoul(options, &options, 0);
804         if (*options && *options != ',') {
805                 printk("EXT4-fs: Invalid sb specification: %s\n",
806                        (char *) *data);
807                 return 1;
808         }
809         if (*options == ',')
810                 options++;
811         *data = (void *) options;
812         return sb_block;
813 }
814
815 static int parse_options (char *options, struct super_block *sb,
816                           unsigned int *inum, unsigned long *journal_devnum,
817                           ext4_fsblk_t *n_blocks_count, int is_remount)
818 {
819         struct ext4_sb_info *sbi = EXT4_SB(sb);
820         char * p;
821         substring_t args[MAX_OPT_ARGS];
822         int data_opt = 0;
823         int option;
824 #ifdef CONFIG_QUOTA
825         int qtype;
826         char *qname;
827 #endif
828
829         if (!options)
830                 return 1;
831
832         while ((p = strsep (&options, ",")) != NULL) {
833                 int token;
834                 if (!*p)
835                         continue;
836
837                 token = match_token(p, tokens, args);
838                 switch (token) {
839                 case Opt_bsd_df:
840                         clear_opt (sbi->s_mount_opt, MINIX_DF);
841                         break;
842                 case Opt_minix_df:
843                         set_opt (sbi->s_mount_opt, MINIX_DF);
844                         break;
845                 case Opt_grpid:
846                         set_opt (sbi->s_mount_opt, GRPID);
847                         break;
848                 case Opt_nogrpid:
849                         clear_opt (sbi->s_mount_opt, GRPID);
850                         break;
851                 case Opt_resuid:
852                         if (match_int(&args[0], &option))
853                                 return 0;
854                         sbi->s_resuid = option;
855                         break;
856                 case Opt_resgid:
857                         if (match_int(&args[0], &option))
858                                 return 0;
859                         sbi->s_resgid = option;
860                         break;
861                 case Opt_sb:
862                         /* handled by get_sb_block() instead of here */
863                         /* *sb_block = match_int(&args[0]); */
864                         break;
865                 case Opt_err_panic:
866                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
867                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
868                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
869                         break;
870                 case Opt_err_ro:
871                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
872                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
873                         set_opt (sbi->s_mount_opt, ERRORS_RO);
874                         break;
875                 case Opt_err_cont:
876                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
877                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
878                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
879                         break;
880                 case Opt_nouid32:
881                         set_opt (sbi->s_mount_opt, NO_UID32);
882                         break;
883                 case Opt_nocheck:
884                         clear_opt (sbi->s_mount_opt, CHECK);
885                         break;
886                 case Opt_debug:
887                         set_opt (sbi->s_mount_opt, DEBUG);
888                         break;
889                 case Opt_oldalloc:
890                         set_opt (sbi->s_mount_opt, OLDALLOC);
891                         break;
892                 case Opt_orlov:
893                         clear_opt (sbi->s_mount_opt, OLDALLOC);
894                         break;
895 #ifdef CONFIG_EXT4DEV_FS_XATTR
896                 case Opt_user_xattr:
897                         set_opt (sbi->s_mount_opt, XATTR_USER);
898                         break;
899                 case Opt_nouser_xattr:
900                         clear_opt (sbi->s_mount_opt, XATTR_USER);
901                         break;
902 #else
903                 case Opt_user_xattr:
904                 case Opt_nouser_xattr:
905                         printk("EXT4 (no)user_xattr options not supported\n");
906                         break;
907 #endif
908 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
909                 case Opt_acl:
910                         set_opt(sbi->s_mount_opt, POSIX_ACL);
911                         break;
912                 case Opt_noacl:
913                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
914                         break;
915 #else
916                 case Opt_acl:
917                 case Opt_noacl:
918                         printk("EXT4 (no)acl options not supported\n");
919                         break;
920 #endif
921                 case Opt_reservation:
922                         set_opt(sbi->s_mount_opt, RESERVATION);
923                         break;
924                 case Opt_noreservation:
925                         clear_opt(sbi->s_mount_opt, RESERVATION);
926                         break;
927                 case Opt_journal_update:
928                         /* @@@ FIXME */
929                         /* Eventually we will want to be able to create
930                            a journal file here.  For now, only allow the
931                            user to specify an existing inode to be the
932                            journal file. */
933                         if (is_remount) {
934                                 printk(KERN_ERR "EXT4-fs: cannot specify "
935                                        "journal on remount\n");
936                                 return 0;
937                         }
938                         set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
939                         break;
940                 case Opt_journal_inum:
941                         if (is_remount) {
942                                 printk(KERN_ERR "EXT4-fs: cannot specify "
943                                        "journal on remount\n");
944                                 return 0;
945                         }
946                         if (match_int(&args[0], &option))
947                                 return 0;
948                         *inum = option;
949                         break;
950                 case Opt_journal_dev:
951                         if (is_remount) {
952                                 printk(KERN_ERR "EXT4-fs: cannot specify "
953                                        "journal on remount\n");
954                                 return 0;
955                         }
956                         if (match_int(&args[0], &option))
957                                 return 0;
958                         *journal_devnum = option;
959                         break;
960                 case Opt_noload:
961                         set_opt (sbi->s_mount_opt, NOLOAD);
962                         break;
963                 case Opt_commit:
964                         if (match_int(&args[0], &option))
965                                 return 0;
966                         if (option < 0)
967                                 return 0;
968                         if (option == 0)
969                                 option = JBD_DEFAULT_MAX_COMMIT_AGE;
970                         sbi->s_commit_interval = HZ * option;
971                         break;
972                 case Opt_data_journal:
973                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
974                         goto datacheck;
975                 case Opt_data_ordered:
976                         data_opt = EXT4_MOUNT_ORDERED_DATA;
977                         goto datacheck;
978                 case Opt_data_writeback:
979                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
980                 datacheck:
981                         if (is_remount) {
982                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
983                                                 != data_opt) {
984                                         printk(KERN_ERR
985                                                 "EXT4-fs: cannot change data "
986                                                 "mode on remount\n");
987                                         return 0;
988                                 }
989                         } else {
990                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
991                                 sbi->s_mount_opt |= data_opt;
992                         }
993                         break;
994 #ifdef CONFIG_QUOTA
995                 case Opt_usrjquota:
996                         qtype = USRQUOTA;
997                         goto set_qf_name;
998                 case Opt_grpjquota:
999                         qtype = GRPQUOTA;
1000 set_qf_name:
1001                         if (sb_any_quota_enabled(sb)) {
1002                                 printk(KERN_ERR
1003                                         "EXT4-fs: Cannot change journalled "
1004                                         "quota options when quota turned on.\n");
1005                                 return 0;
1006                         }
1007                         qname = match_strdup(&args[0]);
1008                         if (!qname) {
1009                                 printk(KERN_ERR
1010                                         "EXT4-fs: not enough memory for "
1011                                         "storing quotafile name.\n");
1012                                 return 0;
1013                         }
1014                         if (sbi->s_qf_names[qtype] &&
1015                             strcmp(sbi->s_qf_names[qtype], qname)) {
1016                                 printk(KERN_ERR
1017                                         "EXT4-fs: %s quota file already "
1018                                         "specified.\n", QTYPE2NAME(qtype));
1019                                 kfree(qname);
1020                                 return 0;
1021                         }
1022                         sbi->s_qf_names[qtype] = qname;
1023                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1024                                 printk(KERN_ERR
1025                                         "EXT4-fs: quotafile must be on "
1026                                         "filesystem root.\n");
1027                                 kfree(sbi->s_qf_names[qtype]);
1028                                 sbi->s_qf_names[qtype] = NULL;
1029                                 return 0;
1030                         }
1031                         set_opt(sbi->s_mount_opt, QUOTA);
1032                         break;
1033                 case Opt_offusrjquota:
1034                         qtype = USRQUOTA;
1035                         goto clear_qf_name;
1036                 case Opt_offgrpjquota:
1037                         qtype = GRPQUOTA;
1038 clear_qf_name:
1039                         if (sb_any_quota_enabled(sb)) {
1040                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1041                                         "journalled quota options when "
1042                                         "quota turned on.\n");
1043                                 return 0;
1044                         }
1045                         /*
1046                          * The space will be released later when all options
1047                          * are confirmed to be correct
1048                          */
1049                         sbi->s_qf_names[qtype] = NULL;
1050                         break;
1051                 case Opt_jqfmt_vfsold:
1052                         sbi->s_jquota_fmt = QFMT_VFS_OLD;
1053                         break;
1054                 case Opt_jqfmt_vfsv0:
1055                         sbi->s_jquota_fmt = QFMT_VFS_V0;
1056                         break;
1057                 case Opt_quota:
1058                 case Opt_usrquota:
1059                         set_opt(sbi->s_mount_opt, QUOTA);
1060                         set_opt(sbi->s_mount_opt, USRQUOTA);
1061                         break;
1062                 case Opt_grpquota:
1063                         set_opt(sbi->s_mount_opt, QUOTA);
1064                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1065                         break;
1066                 case Opt_noquota:
1067                         if (sb_any_quota_enabled(sb)) {
1068                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1069                                         "options when quota turned on.\n");
1070                                 return 0;
1071                         }
1072                         clear_opt(sbi->s_mount_opt, QUOTA);
1073                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1074                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1075                         break;
1076 #else
1077                 case Opt_quota:
1078                 case Opt_usrquota:
1079                 case Opt_grpquota:
1080                 case Opt_usrjquota:
1081                 case Opt_grpjquota:
1082                 case Opt_offusrjquota:
1083                 case Opt_offgrpjquota:
1084                 case Opt_jqfmt_vfsold:
1085                 case Opt_jqfmt_vfsv0:
1086                         printk(KERN_ERR
1087                                 "EXT4-fs: journalled quota options not "
1088                                 "supported.\n");
1089                         break;
1090                 case Opt_noquota:
1091                         break;
1092 #endif
1093                 case Opt_abort:
1094                         set_opt(sbi->s_mount_opt, ABORT);
1095                         break;
1096                 case Opt_barrier:
1097                         if (match_int(&args[0], &option))
1098                                 return 0;
1099                         if (option)
1100                                 set_opt(sbi->s_mount_opt, BARRIER);
1101                         else
1102                                 clear_opt(sbi->s_mount_opt, BARRIER);
1103                         break;
1104                 case Opt_ignore:
1105                         break;
1106                 case Opt_resize:
1107                         if (!is_remount) {
1108                                 printk("EXT4-fs: resize option only available "
1109                                         "for remount\n");
1110                                 return 0;
1111                         }
1112                         if (match_int(&args[0], &option) != 0)
1113                                 return 0;
1114                         *n_blocks_count = option;
1115                         break;
1116                 case Opt_nobh:
1117                         set_opt(sbi->s_mount_opt, NOBH);
1118                         break;
1119                 case Opt_bh:
1120                         clear_opt(sbi->s_mount_opt, NOBH);
1121                         break;
1122                 case Opt_extents:
1123                         set_opt (sbi->s_mount_opt, EXTENTS);
1124                         break;
1125                 case Opt_noextents:
1126                         clear_opt (sbi->s_mount_opt, EXTENTS);
1127                         break;
1128                 default:
1129                         printk (KERN_ERR
1130                                 "EXT4-fs: Unrecognized mount option \"%s\" "
1131                                 "or missing value\n", p);
1132                         return 0;
1133                 }
1134         }
1135 #ifdef CONFIG_QUOTA
1136         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1137                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1138                      sbi->s_qf_names[USRQUOTA])
1139                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1140
1141                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1142                      sbi->s_qf_names[GRPQUOTA])
1143                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1144
1145                 if ((sbi->s_qf_names[USRQUOTA] &&
1146                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1147                     (sbi->s_qf_names[GRPQUOTA] &&
1148                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1149                         printk(KERN_ERR "EXT4-fs: old and new quota "
1150                                         "format mixing.\n");
1151                         return 0;
1152                 }
1153
1154                 if (!sbi->s_jquota_fmt) {
1155                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1156                                         "not specified.\n");
1157                         return 0;
1158                 }
1159         } else {
1160                 if (sbi->s_jquota_fmt) {
1161                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1162                                         "specified with no journalling "
1163                                         "enabled.\n");
1164                         return 0;
1165                 }
1166         }
1167 #endif
1168         return 1;
1169 }
1170
1171 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1172                             int read_only)
1173 {
1174         struct ext4_sb_info *sbi = EXT4_SB(sb);
1175         int res = 0;
1176
1177         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1178                 printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1179                         "forcing read-only mode\n");
1180                 res = MS_RDONLY;
1181         }
1182         if (read_only)
1183                 return res;
1184         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1185                 printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1186                         "running e2fsck is recommended\n");
1187         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1188                 printk (KERN_WARNING
1189                         "EXT4-fs warning: mounting fs with errors, "
1190                         "running e2fsck is recommended\n");
1191         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1192                  le16_to_cpu(es->s_mnt_count) >=
1193                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1194                 printk (KERN_WARNING
1195                         "EXT4-fs warning: maximal mount count reached, "
1196                         "running e2fsck is recommended\n");
1197         else if (le32_to_cpu(es->s_checkinterval) &&
1198                 (le32_to_cpu(es->s_lastcheck) +
1199                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1200                 printk (KERN_WARNING
1201                         "EXT4-fs warning: checktime reached, "
1202                         "running e2fsck is recommended\n");
1203 #if 0
1204                 /* @@@ We _will_ want to clear the valid bit if we find
1205                  * inconsistencies, to force a fsck at reboot.  But for
1206                  * a plain journaled filesystem we can keep it set as
1207                  * valid forever! :)
1208                  */
1209         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT4_VALID_FS);
1210 #endif
1211         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1212                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1213         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
1214         es->s_mtime = cpu_to_le32(get_seconds());
1215         ext4_update_dynamic_rev(sb);
1216         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1217
1218         ext4_commit_super(sb, es, 1);
1219         if (test_opt(sb, DEBUG))
1220                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1221                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1222                         sb->s_blocksize,
1223                         sbi->s_groups_count,
1224                         EXT4_BLOCKS_PER_GROUP(sb),
1225                         EXT4_INODES_PER_GROUP(sb),
1226                         sbi->s_mount_opt);
1227
1228         printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1229         if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1230                 char b[BDEVNAME_SIZE];
1231
1232                 printk("external journal on %s\n",
1233                         bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1234         } else {
1235                 printk("internal journal\n");
1236         }
1237         return res;
1238 }
1239
1240 /* Called at mount-time, super-block is locked */
1241 static int ext4_check_descriptors (struct super_block * sb)
1242 {
1243         struct ext4_sb_info *sbi = EXT4_SB(sb);
1244         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1245         ext4_fsblk_t last_block;
1246         ext4_fsblk_t block_bitmap;
1247         ext4_fsblk_t inode_bitmap;
1248         ext4_fsblk_t inode_table;
1249         struct ext4_group_desc * gdp = NULL;
1250         int desc_block = 0;
1251         int i;
1252
1253         ext4_debug ("Checking group descriptors");
1254
1255         for (i = 0; i < sbi->s_groups_count; i++)
1256         {
1257                 if (i == sbi->s_groups_count - 1)
1258                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1259                 else
1260                         last_block = first_block +
1261                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1262
1263                 if ((i % EXT4_DESC_PER_BLOCK(sb)) == 0)
1264                         gdp = (struct ext4_group_desc *)
1265                                         sbi->s_group_desc[desc_block++]->b_data;
1266                 block_bitmap = ext4_block_bitmap(sb, gdp);
1267                 if (block_bitmap < first_block || block_bitmap > last_block)
1268                 {
1269                         ext4_error (sb, "ext4_check_descriptors",
1270                                     "Block bitmap for group %d"
1271                                     " not in group (block %llu)!",
1272                                     i, block_bitmap);
1273                         return 0;
1274                 }
1275                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1276                 if (inode_bitmap < first_block || inode_bitmap > last_block)
1277                 {
1278                         ext4_error (sb, "ext4_check_descriptors",
1279                                     "Inode bitmap for group %d"
1280                                     " not in group (block %llu)!",
1281                                     i, inode_bitmap);
1282                         return 0;
1283                 }
1284                 inode_table = ext4_inode_table(sb, gdp);
1285                 if (inode_table < first_block ||
1286                     inode_table + sbi->s_itb_per_group > last_block)
1287                 {
1288                         ext4_error (sb, "ext4_check_descriptors",
1289                                     "Inode table for group %d"
1290                                     " not in group (block %llu)!",
1291                                     i, inode_table);
1292                         return 0;
1293                 }
1294                 first_block += EXT4_BLOCKS_PER_GROUP(sb);
1295                 gdp = (struct ext4_group_desc *)
1296                         ((__u8 *)gdp + EXT4_DESC_SIZE(sb));
1297         }
1298
1299         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1300         sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1301         return 1;
1302 }
1303
1304
1305 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1306  * the superblock) which were deleted from all directories, but held open by
1307  * a process at the time of a crash.  We walk the list and try to delete these
1308  * inodes at recovery time (only with a read-write filesystem).
1309  *
1310  * In order to keep the orphan inode chain consistent during traversal (in
1311  * case of crash during recovery), we link each inode into the superblock
1312  * orphan list_head and handle it the same way as an inode deletion during
1313  * normal operation (which journals the operations for us).
1314  *
1315  * We only do an iget() and an iput() on each inode, which is very safe if we
1316  * accidentally point at an in-use or already deleted inode.  The worst that
1317  * can happen in this case is that we get a "bit already cleared" message from
1318  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1319  * e2fsck was run on this filesystem, and it must have already done the orphan
1320  * inode cleanup for us, so we can safely abort without any further action.
1321  */
1322 static void ext4_orphan_cleanup (struct super_block * sb,
1323                                  struct ext4_super_block * es)
1324 {
1325         unsigned int s_flags = sb->s_flags;
1326         int nr_orphans = 0, nr_truncates = 0;
1327 #ifdef CONFIG_QUOTA
1328         int i;
1329 #endif
1330         if (!es->s_last_orphan) {
1331                 jbd_debug(4, "no orphan inodes to clean up\n");
1332                 return;
1333         }
1334
1335         if (bdev_read_only(sb->s_bdev)) {
1336                 printk(KERN_ERR "EXT4-fs: write access "
1337                         "unavailable, skipping orphan cleanup.\n");
1338                 return;
1339         }
1340
1341         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1342                 if (es->s_last_orphan)
1343                         jbd_debug(1, "Errors on filesystem, "
1344                                   "clearing orphan list.\n");
1345                 es->s_last_orphan = 0;
1346                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1347                 return;
1348         }
1349
1350         if (s_flags & MS_RDONLY) {
1351                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1352                        sb->s_id);
1353                 sb->s_flags &= ~MS_RDONLY;
1354         }
1355 #ifdef CONFIG_QUOTA
1356         /* Needed for iput() to work correctly and not trash data */
1357         sb->s_flags |= MS_ACTIVE;
1358         /* Turn on quotas so that they are updated correctly */
1359         for (i = 0; i < MAXQUOTAS; i++) {
1360                 if (EXT4_SB(sb)->s_qf_names[i]) {
1361                         int ret = ext4_quota_on_mount(sb, i);
1362                         if (ret < 0)
1363                                 printk(KERN_ERR
1364                                         "EXT4-fs: Cannot turn on journalled "
1365                                         "quota: error %d\n", ret);
1366                 }
1367         }
1368 #endif
1369
1370         while (es->s_last_orphan) {
1371                 struct inode *inode;
1372
1373                 if (!(inode =
1374                       ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
1375                         es->s_last_orphan = 0;
1376                         break;
1377                 }
1378
1379                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1380                 DQUOT_INIT(inode);
1381                 if (inode->i_nlink) {
1382                         printk(KERN_DEBUG
1383                                 "%s: truncating inode %lu to %Ld bytes\n",
1384                                 __FUNCTION__, inode->i_ino, inode->i_size);
1385                         jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1386                                   inode->i_ino, inode->i_size);
1387                         ext4_truncate(inode);
1388                         nr_truncates++;
1389                 } else {
1390                         printk(KERN_DEBUG
1391                                 "%s: deleting unreferenced inode %lu\n",
1392                                 __FUNCTION__, inode->i_ino);
1393                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1394                                   inode->i_ino);
1395                         nr_orphans++;
1396                 }
1397                 iput(inode);  /* The delete magic happens here! */
1398         }
1399
1400 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1401
1402         if (nr_orphans)
1403                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1404                        sb->s_id, PLURAL(nr_orphans));
1405         if (nr_truncates)
1406                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1407                        sb->s_id, PLURAL(nr_truncates));
1408 #ifdef CONFIG_QUOTA
1409         /* Turn quotas off */
1410         for (i = 0; i < MAXQUOTAS; i++) {
1411                 if (sb_dqopt(sb)->files[i])
1412                         vfs_quota_off(sb, i);
1413         }
1414 #endif
1415         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1416 }
1417
1418 #define log2(n) ffz(~(n))
1419
1420 /*
1421  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
1422  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
1423  * We need to be 1 filesystem block less than the 2^32 sector limit.
1424  */
1425 static loff_t ext4_max_size(int bits)
1426 {
1427         loff_t res = EXT4_NDIR_BLOCKS;
1428         /* This constant is calculated to be the largest file size for a
1429          * dense, 4k-blocksize file such that the total number of
1430          * sectors in the file, including data and all indirect blocks,
1431          * does not exceed 2^32. */
1432         const loff_t upper_limit = 0x1ff7fffd000LL;
1433
1434         res += 1LL << (bits-2);
1435         res += 1LL << (2*(bits-2));
1436         res += 1LL << (3*(bits-2));
1437         res <<= bits;
1438         if (res > upper_limit)
1439                 res = upper_limit;
1440         return res;
1441 }
1442
1443 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1444                                 ext4_fsblk_t logical_sb_block, int nr)
1445 {
1446         struct ext4_sb_info *sbi = EXT4_SB(sb);
1447         unsigned long bg, first_meta_bg;
1448         int has_super = 0;
1449
1450         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1451
1452         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1453             nr < first_meta_bg)
1454                 return logical_sb_block + nr + 1;
1455         bg = sbi->s_desc_per_block * nr;
1456         if (ext4_bg_has_super(sb, bg))
1457                 has_super = 1;
1458         return (has_super + ext4_group_first_block_no(sb, bg));
1459 }
1460
1461
1462 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1463 {
1464         struct buffer_head * bh;
1465         struct ext4_super_block *es = NULL;
1466         struct ext4_sb_info *sbi;
1467         ext4_fsblk_t block;
1468         ext4_fsblk_t sb_block = get_sb_block(&data);
1469         ext4_fsblk_t logical_sb_block;
1470         unsigned long offset = 0;
1471         unsigned int journal_inum = 0;
1472         unsigned long journal_devnum = 0;
1473         unsigned long def_mount_opts;
1474         struct inode *root;
1475         int blocksize;
1476         int hblock;
1477         int db_count;
1478         int i;
1479         int needs_recovery;
1480         __le32 features;
1481         __u64 blocks_count;
1482
1483         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1484         if (!sbi)
1485                 return -ENOMEM;
1486         sb->s_fs_info = sbi;
1487         sbi->s_mount_opt = 0;
1488         sbi->s_resuid = EXT4_DEF_RESUID;
1489         sbi->s_resgid = EXT4_DEF_RESGID;
1490
1491         unlock_kernel();
1492
1493         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1494         if (!blocksize) {
1495                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1496                 goto out_fail;
1497         }
1498
1499         /*
1500          * The ext4 superblock will not be buffer aligned for other than 1kB
1501          * block sizes.  We need to calculate the offset from buffer start.
1502          */
1503         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1504                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1505                 offset = do_div(logical_sb_block, blocksize);
1506         } else {
1507                 logical_sb_block = sb_block;
1508         }
1509
1510         if (!(bh = sb_bread(sb, logical_sb_block))) {
1511                 printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1512                 goto out_fail;
1513         }
1514         /*
1515          * Note: s_es must be initialized as soon as possible because
1516          *       some ext4 macro-instructions depend on its value
1517          */
1518         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1519         sbi->s_es = es;
1520         sb->s_magic = le16_to_cpu(es->s_magic);
1521         if (sb->s_magic != EXT4_SUPER_MAGIC)
1522                 goto cantfind_ext4;
1523
1524         /* Set defaults before we parse the mount options */
1525         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1526         if (def_mount_opts & EXT4_DEFM_DEBUG)
1527                 set_opt(sbi->s_mount_opt, DEBUG);
1528         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1529                 set_opt(sbi->s_mount_opt, GRPID);
1530         if (def_mount_opts & EXT4_DEFM_UID16)
1531                 set_opt(sbi->s_mount_opt, NO_UID32);
1532 #ifdef CONFIG_EXT4DEV_FS_XATTR
1533         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1534                 set_opt(sbi->s_mount_opt, XATTR_USER);
1535 #endif
1536 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1537         if (def_mount_opts & EXT4_DEFM_ACL)
1538                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1539 #endif
1540         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1541                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1542         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1543                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1544         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1545                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1546
1547         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1548                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1549         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_RO)
1550                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1551         else
1552                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1553
1554         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1555         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1556
1557         set_opt(sbi->s_mount_opt, RESERVATION);
1558
1559         /*
1560          * turn on extents feature by default in ext4 filesystem
1561          * User -o noextents to turn it off
1562          */
1563         set_opt(sbi->s_mount_opt, EXTENTS);
1564
1565         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1566                             NULL, 0))
1567                 goto failed_mount;
1568
1569         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1570                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1571
1572         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1573             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1574              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1575              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1576                 printk(KERN_WARNING
1577                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1578                        "running e2fsck is recommended\n");
1579         /*
1580          * Check feature flags regardless of the revision level, since we
1581          * previously didn't change the revision level when setting the flags,
1582          * so there is a chance incompat flags are set on a rev 0 filesystem.
1583          */
1584         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1585         if (features) {
1586                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1587                        "unsupported optional features (%x).\n",
1588                        sb->s_id, le32_to_cpu(features));
1589                 goto failed_mount;
1590         }
1591         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1592         if (!(sb->s_flags & MS_RDONLY) && features) {
1593                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1594                        "unsupported optional features (%x).\n",
1595                        sb->s_id, le32_to_cpu(features));
1596                 goto failed_mount;
1597         }
1598         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1599
1600         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1601             blocksize > EXT4_MAX_BLOCK_SIZE) {
1602                 printk(KERN_ERR
1603                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1604                        blocksize, sb->s_id);
1605                 goto failed_mount;
1606         }
1607
1608         hblock = bdev_hardsect_size(sb->s_bdev);
1609         if (sb->s_blocksize != blocksize) {
1610                 /*
1611                  * Make sure the blocksize for the filesystem is larger
1612                  * than the hardware sectorsize for the machine.
1613                  */
1614                 if (blocksize < hblock) {
1615                         printk(KERN_ERR "EXT4-fs: blocksize %d too small for "
1616                                "device blocksize %d.\n", blocksize, hblock);
1617                         goto failed_mount;
1618                 }
1619
1620                 brelse (bh);
1621                 sb_set_blocksize(sb, blocksize);
1622                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1623                 offset = do_div(logical_sb_block, blocksize);
1624                 bh = sb_bread(sb, logical_sb_block);
1625                 if (!bh) {
1626                         printk(KERN_ERR
1627                                "EXT4-fs: Can't read superblock on 2nd try.\n");
1628                         goto failed_mount;
1629                 }
1630                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1631                 sbi->s_es = es;
1632                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1633                         printk (KERN_ERR
1634                                 "EXT4-fs: Magic mismatch, very weird !\n");
1635                         goto failed_mount;
1636                 }
1637         }
1638
1639         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
1640
1641         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
1642                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
1643                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
1644         } else {
1645                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1646                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1647                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
1648                     (!is_power_of_2(sbi->s_inode_size)) ||
1649                     (sbi->s_inode_size > blocksize)) {
1650                         printk (KERN_ERR
1651                                 "EXT4-fs: unsupported inode size: %d\n",
1652                                 sbi->s_inode_size);
1653                         goto failed_mount;
1654                 }
1655                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
1656                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
1657         }
1658         sbi->s_frag_size = EXT4_MIN_FRAG_SIZE <<
1659                                    le32_to_cpu(es->s_log_frag_size);
1660         if (blocksize != sbi->s_frag_size) {
1661                 printk(KERN_ERR
1662                        "EXT4-fs: fragsize %lu != blocksize %u (unsupported)\n",
1663                        sbi->s_frag_size, blocksize);
1664                 goto failed_mount;
1665         }
1666         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
1667         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
1668                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
1669                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
1670                     sbi->s_desc_size & (sbi->s_desc_size - 1)) {
1671                         printk(KERN_ERR
1672                                "EXT4-fs: unsupported descriptor size %lu\n",
1673                                sbi->s_desc_size);
1674                         goto failed_mount;
1675                 }
1676         } else
1677                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
1678         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1679         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1680         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1681         if (EXT4_INODE_SIZE(sb) == 0)
1682                 goto cantfind_ext4;
1683         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
1684         if (sbi->s_inodes_per_block == 0)
1685                 goto cantfind_ext4;
1686         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1687                                         sbi->s_inodes_per_block;
1688         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
1689         sbi->s_sbh = bh;
1690         sbi->s_mount_state = le16_to_cpu(es->s_state);
1691         sbi->s_addr_per_block_bits = log2(EXT4_ADDR_PER_BLOCK(sb));
1692         sbi->s_desc_per_block_bits = log2(EXT4_DESC_PER_BLOCK(sb));
1693         for (i=0; i < 4; i++)
1694                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
1695         sbi->s_def_hash_version = es->s_def_hash_version;
1696
1697         if (sbi->s_blocks_per_group > blocksize * 8) {
1698                 printk (KERN_ERR
1699                         "EXT4-fs: #blocks per group too big: %lu\n",
1700                         sbi->s_blocks_per_group);
1701                 goto failed_mount;
1702         }
1703         if (sbi->s_frags_per_group > blocksize * 8) {
1704                 printk (KERN_ERR
1705                         "EXT4-fs: #fragments per group too big: %lu\n",
1706                         sbi->s_frags_per_group);
1707                 goto failed_mount;
1708         }
1709         if (sbi->s_inodes_per_group > blocksize * 8) {
1710                 printk (KERN_ERR
1711                         "EXT4-fs: #inodes per group too big: %lu\n",
1712                         sbi->s_inodes_per_group);
1713                 goto failed_mount;
1714         }
1715
1716         if (ext4_blocks_count(es) >
1717                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1718                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
1719                         " too large to mount safely\n", sb->s_id);
1720                 if (sizeof(sector_t) < 8)
1721                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
1722                                         "enabled\n");
1723                 goto failed_mount;
1724         }
1725
1726         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
1727                 goto cantfind_ext4;
1728         blocks_count = (ext4_blocks_count(es) -
1729                         le32_to_cpu(es->s_first_data_block) +
1730                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
1731         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
1732         sbi->s_groups_count = blocks_count;
1733         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
1734                    EXT4_DESC_PER_BLOCK(sb);
1735         sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
1736                                     GFP_KERNEL);
1737         if (sbi->s_group_desc == NULL) {
1738                 printk (KERN_ERR "EXT4-fs: not enough memory\n");
1739                 goto failed_mount;
1740         }
1741
1742         bgl_lock_init(&sbi->s_blockgroup_lock);
1743
1744         for (i = 0; i < db_count; i++) {
1745                 block = descriptor_loc(sb, logical_sb_block, i);
1746                 sbi->s_group_desc[i] = sb_bread(sb, block);
1747                 if (!sbi->s_group_desc[i]) {
1748                         printk (KERN_ERR "EXT4-fs: "
1749                                 "can't read group descriptor %d\n", i);
1750                         db_count = i;
1751                         goto failed_mount2;
1752                 }
1753         }
1754         if (!ext4_check_descriptors (sb)) {
1755                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
1756                 goto failed_mount2;
1757         }
1758         sbi->s_gdb_count = db_count;
1759         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1760         spin_lock_init(&sbi->s_next_gen_lock);
1761
1762         percpu_counter_init(&sbi->s_freeblocks_counter,
1763                 ext4_count_free_blocks(sb));
1764         percpu_counter_init(&sbi->s_freeinodes_counter,
1765                 ext4_count_free_inodes(sb));
1766         percpu_counter_init(&sbi->s_dirs_counter,
1767                 ext4_count_dirs(sb));
1768
1769         /* per fileystem reservation list head & lock */
1770         spin_lock_init(&sbi->s_rsv_window_lock);
1771         sbi->s_rsv_window_root = RB_ROOT;
1772         /* Add a single, static dummy reservation to the start of the
1773          * reservation window list --- it gives us a placeholder for
1774          * append-at-start-of-list which makes the allocation logic
1775          * _much_ simpler. */
1776         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1777         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1778         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1779         sbi->s_rsv_window_head.rsv_goal_size = 0;
1780         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
1781
1782         /*
1783          * set up enough so that it can read an inode
1784          */
1785         sb->s_op = &ext4_sops;
1786         sb->s_export_op = &ext4_export_ops;
1787         sb->s_xattr = ext4_xattr_handlers;
1788 #ifdef CONFIG_QUOTA
1789         sb->s_qcop = &ext4_qctl_operations;
1790         sb->dq_op = &ext4_quota_operations;
1791 #endif
1792         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
1793
1794         sb->s_root = NULL;
1795
1796         needs_recovery = (es->s_last_orphan != 0 ||
1797                           EXT4_HAS_INCOMPAT_FEATURE(sb,
1798                                     EXT4_FEATURE_INCOMPAT_RECOVER));
1799
1800         /*
1801          * The first inode we look at is the journal inode.  Don't try
1802          * root first: it may be modified in the journal!
1803          */
1804         if (!test_opt(sb, NOLOAD) &&
1805             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
1806                 if (ext4_load_journal(sb, es, journal_devnum))
1807                         goto failed_mount3;
1808         } else if (journal_inum) {
1809                 if (ext4_create_journal(sb, es, journal_inum))
1810                         goto failed_mount3;
1811         } else {
1812                 if (!silent)
1813                         printk (KERN_ERR
1814                                 "ext4: No journal on filesystem on %s\n",
1815                                 sb->s_id);
1816                 goto failed_mount3;
1817         }
1818
1819         if (ext4_blocks_count(es) > 0xffffffffULL &&
1820             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
1821                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
1822                 printk(KERN_ERR "ext4: Failed to set 64-bit journal feature\n");
1823                 goto failed_mount4;
1824         }
1825
1826         /* We have now updated the journal if required, so we can
1827          * validate the data journaling mode. */
1828         switch (test_opt(sb, DATA_FLAGS)) {
1829         case 0:
1830                 /* No mode set, assume a default based on the journal
1831                  * capabilities: ORDERED_DATA if the journal can
1832                  * cope, else JOURNAL_DATA
1833                  */
1834                 if (jbd2_journal_check_available_features
1835                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
1836                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
1837                 else
1838                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
1839                 break;
1840
1841         case EXT4_MOUNT_ORDERED_DATA:
1842         case EXT4_MOUNT_WRITEBACK_DATA:
1843                 if (!jbd2_journal_check_available_features
1844                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
1845                         printk(KERN_ERR "EXT4-fs: Journal does not support "
1846                                "requested data journaling mode\n");
1847                         goto failed_mount4;
1848                 }
1849         default:
1850                 break;
1851         }
1852
1853         if (test_opt(sb, NOBH)) {
1854                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
1855                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
1856                                 "its supported only with writeback mode\n");
1857                         clear_opt(sbi->s_mount_opt, NOBH);
1858                 }
1859         }
1860         /*
1861          * The jbd2_journal_load will have done any necessary log recovery,
1862          * so we can safely mount the rest of the filesystem now.
1863          */
1864
1865         root = iget(sb, EXT4_ROOT_INO);
1866         sb->s_root = d_alloc_root(root);
1867         if (!sb->s_root) {
1868                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
1869                 iput(root);
1870                 goto failed_mount4;
1871         }
1872         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1873                 dput(sb->s_root);
1874                 sb->s_root = NULL;
1875                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
1876                 goto failed_mount4;
1877         }
1878
1879         ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1880
1881         /* determine the minimum size of new large inodes, if present */
1882         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
1883                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
1884                                                      EXT4_GOOD_OLD_INODE_SIZE;
1885                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1886                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
1887                         if (sbi->s_want_extra_isize <
1888                             le16_to_cpu(es->s_want_extra_isize))
1889                                 sbi->s_want_extra_isize =
1890                                         le16_to_cpu(es->s_want_extra_isize);
1891                         if (sbi->s_want_extra_isize <
1892                             le16_to_cpu(es->s_min_extra_isize))
1893                                 sbi->s_want_extra_isize =
1894                                         le16_to_cpu(es->s_min_extra_isize);
1895                 }
1896         }
1897         /* Check if enough inode space is available */
1898         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
1899                                                         sbi->s_inode_size) {
1900                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
1901                                                        EXT4_GOOD_OLD_INODE_SIZE;
1902                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
1903                         "available.\n");
1904         }
1905
1906         /*
1907          * akpm: core read_super() calls in here with the superblock locked.
1908          * That deadlocks, because orphan cleanup needs to lock the superblock
1909          * in numerous places.  Here we just pop the lock - it's relatively
1910          * harmless, because we are now ready to accept write_super() requests,
1911          * and aviro says that's the only reason for hanging onto the
1912          * superblock lock.
1913          */
1914         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
1915         ext4_orphan_cleanup(sb, es);
1916         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
1917         if (needs_recovery)
1918                 printk (KERN_INFO "EXT4-fs: recovery complete.\n");
1919         ext4_mark_recovery_complete(sb, es);
1920         printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
1921                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
1922                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
1923                 "writeback");
1924
1925         ext4_ext_init(sb);
1926
1927         lock_kernel();
1928         return 0;
1929
1930 cantfind_ext4:
1931         if (!silent)
1932                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
1933                        sb->s_id);
1934         goto failed_mount;
1935
1936 failed_mount4:
1937         jbd2_journal_destroy(sbi->s_journal);
1938 failed_mount3:
1939         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1940         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1941         percpu_counter_destroy(&sbi->s_dirs_counter);
1942 failed_mount2:
1943         for (i = 0; i < db_count; i++)
1944                 brelse(sbi->s_group_desc[i]);
1945         kfree(sbi->s_group_desc);
1946 failed_mount:
1947 #ifdef CONFIG_QUOTA
1948         for (i = 0; i < MAXQUOTAS; i++)
1949                 kfree(sbi->s_qf_names[i]);
1950 #endif
1951         ext4_blkdev_remove(sbi);
1952         brelse(bh);
1953 out_fail:
1954         sb->s_fs_info = NULL;
1955         kfree(sbi);
1956         lock_kernel();
1957         return -EINVAL;
1958 }
1959
1960 /*
1961  * Setup any per-fs journal parameters now.  We'll do this both on
1962  * initial mount, once the journal has been initialised but before we've
1963  * done any recovery; and again on any subsequent remount.
1964  */
1965 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
1966 {
1967         struct ext4_sb_info *sbi = EXT4_SB(sb);
1968
1969         if (sbi->s_commit_interval)
1970                 journal->j_commit_interval = sbi->s_commit_interval;
1971         /* We could also set up an ext4-specific default for the commit
1972          * interval here, but for now we'll just fall back to the jbd
1973          * default. */
1974
1975         spin_lock(&journal->j_state_lock);
1976         if (test_opt(sb, BARRIER))
1977                 journal->j_flags |= JBD2_BARRIER;
1978         else
1979                 journal->j_flags &= ~JBD2_BARRIER;
1980         spin_unlock(&journal->j_state_lock);
1981 }
1982
1983 static journal_t *ext4_get_journal(struct super_block *sb,
1984                                    unsigned int journal_inum)
1985 {
1986         struct inode *journal_inode;
1987         journal_t *journal;
1988
1989         /* First, test for the existence of a valid inode on disk.  Bad
1990          * things happen if we iget() an unused inode, as the subsequent
1991          * iput() will try to delete it. */
1992
1993         journal_inode = iget(sb, journal_inum);
1994         if (!journal_inode) {
1995                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
1996                 return NULL;
1997         }
1998         if (!journal_inode->i_nlink) {
1999                 make_bad_inode(journal_inode);
2000                 iput(journal_inode);
2001                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2002                 return NULL;
2003         }
2004
2005         jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
2006                   journal_inode, journal_inode->i_size);
2007         if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
2008                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2009                 iput(journal_inode);
2010                 return NULL;
2011         }
2012
2013         journal = jbd2_journal_init_inode(journal_inode);
2014         if (!journal) {
2015                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2016                 iput(journal_inode);
2017                 return NULL;
2018         }
2019         journal->j_private = sb;
2020         ext4_init_journal_params(sb, journal);
2021         return journal;
2022 }
2023
2024 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2025                                        dev_t j_dev)
2026 {
2027         struct buffer_head * bh;
2028         journal_t *journal;
2029         ext4_fsblk_t start;
2030         ext4_fsblk_t len;
2031         int hblock, blocksize;
2032         ext4_fsblk_t sb_block;
2033         unsigned long offset;
2034         struct ext4_super_block * es;
2035         struct block_device *bdev;
2036
2037         bdev = ext4_blkdev_get(j_dev);
2038         if (bdev == NULL)
2039                 return NULL;
2040
2041         if (bd_claim(bdev, sb)) {
2042                 printk(KERN_ERR
2043                         "EXT4: failed to claim external journal device.\n");
2044                 blkdev_put(bdev);
2045                 return NULL;
2046         }
2047
2048         blocksize = sb->s_blocksize;
2049         hblock = bdev_hardsect_size(bdev);
2050         if (blocksize < hblock) {
2051                 printk(KERN_ERR
2052                         "EXT4-fs: blocksize too small for journal device.\n");
2053                 goto out_bdev;
2054         }
2055
2056         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2057         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2058         set_blocksize(bdev, blocksize);
2059         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2060                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2061                        "external journal\n");
2062                 goto out_bdev;
2063         }
2064
2065         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2066         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2067             !(le32_to_cpu(es->s_feature_incompat) &
2068               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2069                 printk(KERN_ERR "EXT4-fs: external journal has "
2070                                         "bad superblock\n");
2071                 brelse(bh);
2072                 goto out_bdev;
2073         }
2074
2075         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2076                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2077                 brelse(bh);
2078                 goto out_bdev;
2079         }
2080
2081         len = ext4_blocks_count(es);
2082         start = sb_block + 1;
2083         brelse(bh);     /* we're done with the superblock */
2084
2085         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2086                                         start, len, blocksize);
2087         if (!journal) {
2088                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2089                 goto out_bdev;
2090         }
2091         journal->j_private = sb;
2092         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2093         wait_on_buffer(journal->j_sb_buffer);
2094         if (!buffer_uptodate(journal->j_sb_buffer)) {
2095                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2096                 goto out_journal;
2097         }
2098         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2099                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2100                                         "user (unsupported) - %d\n",
2101                         be32_to_cpu(journal->j_superblock->s_nr_users));
2102                 goto out_journal;
2103         }
2104         EXT4_SB(sb)->journal_bdev = bdev;
2105         ext4_init_journal_params(sb, journal);
2106         return journal;
2107 out_journal:
2108         jbd2_journal_destroy(journal);
2109 out_bdev:
2110         ext4_blkdev_put(bdev);
2111         return NULL;
2112 }
2113
2114 static int ext4_load_journal(struct super_block *sb,
2115                              struct ext4_super_block *es,
2116                              unsigned long journal_devnum)
2117 {
2118         journal_t *journal;
2119         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2120         dev_t journal_dev;
2121         int err = 0;
2122         int really_read_only;
2123
2124         if (journal_devnum &&
2125             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2126                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2127                         "numbers have changed\n");
2128                 journal_dev = new_decode_dev(journal_devnum);
2129         } else
2130                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2131
2132         really_read_only = bdev_read_only(sb->s_bdev);
2133
2134         /*
2135          * Are we loading a blank journal or performing recovery after a
2136          * crash?  For recovery, we need to check in advance whether we
2137          * can get read-write access to the device.
2138          */
2139
2140         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2141                 if (sb->s_flags & MS_RDONLY) {
2142                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2143                                         "required on readonly filesystem.\n");
2144                         if (really_read_only) {
2145                                 printk(KERN_ERR "EXT4-fs: write access "
2146                                         "unavailable, cannot proceed.\n");
2147                                 return -EROFS;
2148                         }
2149                         printk (KERN_INFO "EXT4-fs: write access will "
2150                                         "be enabled during recovery.\n");
2151                 }
2152         }
2153
2154         if (journal_inum && journal_dev) {
2155                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2156                        "and inode journals!\n");
2157                 return -EINVAL;
2158         }
2159
2160         if (journal_inum) {
2161                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2162                         return -EINVAL;
2163         } else {
2164                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2165                         return -EINVAL;
2166         }
2167
2168         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2169                 err = jbd2_journal_update_format(journal);
2170                 if (err)  {
2171                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2172                         jbd2_journal_destroy(journal);
2173                         return err;
2174                 }
2175         }
2176
2177         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2178                 err = jbd2_journal_wipe(journal, !really_read_only);
2179         if (!err)
2180                 err = jbd2_journal_load(journal);
2181
2182         if (err) {
2183                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2184                 jbd2_journal_destroy(journal);
2185                 return err;
2186         }
2187
2188         EXT4_SB(sb)->s_journal = journal;
2189         ext4_clear_journal_err(sb, es);
2190
2191         if (journal_devnum &&
2192             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2193                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2194                 sb->s_dirt = 1;
2195
2196                 /* Make sure we flush the recovery flag to disk. */
2197                 ext4_commit_super(sb, es, 1);
2198         }
2199
2200         return 0;
2201 }
2202
2203 static int ext4_create_journal(struct super_block * sb,
2204                                struct ext4_super_block * es,
2205                                unsigned int journal_inum)
2206 {
2207         journal_t *journal;
2208         int err;
2209
2210         if (sb->s_flags & MS_RDONLY) {
2211                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2212                                 "create journal.\n");
2213                 return -EROFS;
2214         }
2215
2216         journal = ext4_get_journal(sb, journal_inum);
2217         if (!journal)
2218                 return -EINVAL;
2219
2220         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2221                journal_inum);
2222
2223         err = jbd2_journal_create(journal);
2224         if (err) {
2225                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2226                 jbd2_journal_destroy(journal);
2227                 return -EIO;
2228         }
2229
2230         EXT4_SB(sb)->s_journal = journal;
2231
2232         ext4_update_dynamic_rev(sb);
2233         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2234         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2235
2236         es->s_journal_inum = cpu_to_le32(journal_inum);
2237         sb->s_dirt = 1;
2238
2239         /* Make sure we flush the recovery flag to disk. */
2240         ext4_commit_super(sb, es, 1);
2241
2242         return 0;
2243 }
2244
2245 static void ext4_commit_super (struct super_block * sb,
2246                                struct ext4_super_block * es,
2247                                int sync)
2248 {
2249         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2250
2251         if (!sbh)
2252                 return;
2253         es->s_wtime = cpu_to_le32(get_seconds());
2254         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2255         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2256         BUFFER_TRACE(sbh, "marking dirty");
2257         mark_buffer_dirty(sbh);
2258         if (sync)
2259                 sync_dirty_buffer(sbh);
2260 }
2261
2262
2263 /*
2264  * Have we just finished recovery?  If so, and if we are mounting (or
2265  * remounting) the filesystem readonly, then we will end up with a
2266  * consistent fs on disk.  Record that fact.
2267  */
2268 static void ext4_mark_recovery_complete(struct super_block * sb,
2269                                         struct ext4_super_block * es)
2270 {
2271         journal_t *journal = EXT4_SB(sb)->s_journal;
2272
2273         jbd2_journal_lock_updates(journal);
2274         jbd2_journal_flush(journal);
2275         lock_super(sb);
2276         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2277             sb->s_flags & MS_RDONLY) {
2278                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2279                 sb->s_dirt = 0;
2280                 ext4_commit_super(sb, es, 1);
2281         }
2282         unlock_super(sb);
2283         jbd2_journal_unlock_updates(journal);
2284 }
2285
2286 /*
2287  * If we are mounting (or read-write remounting) a filesystem whose journal
2288  * has recorded an error from a previous lifetime, move that error to the
2289  * main filesystem now.
2290  */
2291 static void ext4_clear_journal_err(struct super_block * sb,
2292                                    struct ext4_super_block * es)
2293 {
2294         journal_t *journal;
2295         int j_errno;
2296         const char *errstr;
2297
2298         journal = EXT4_SB(sb)->s_journal;
2299
2300         /*
2301          * Now check for any error status which may have been recorded in the
2302          * journal by a prior ext4_error() or ext4_abort()
2303          */
2304
2305         j_errno = jbd2_journal_errno(journal);
2306         if (j_errno) {
2307                 char nbuf[16];
2308
2309                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2310                 ext4_warning(sb, __FUNCTION__, "Filesystem error recorded "
2311                              "from previous mount: %s", errstr);
2312                 ext4_warning(sb, __FUNCTION__, "Marking fs in need of "
2313                              "filesystem check.");
2314
2315                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2316                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2317                 ext4_commit_super (sb, es, 1);
2318
2319                 jbd2_journal_clear_err(journal);
2320         }
2321 }
2322
2323 /*
2324  * Force the running and committing transactions to commit,
2325  * and wait on the commit.
2326  */
2327 int ext4_force_commit(struct super_block *sb)
2328 {
2329         journal_t *journal;
2330         int ret;
2331
2332         if (sb->s_flags & MS_RDONLY)
2333                 return 0;
2334
2335         journal = EXT4_SB(sb)->s_journal;
2336         sb->s_dirt = 0;
2337         ret = ext4_journal_force_commit(journal);
2338         return ret;
2339 }
2340
2341 /*
2342  * Ext4 always journals updates to the superblock itself, so we don't
2343  * have to propagate any other updates to the superblock on disk at this
2344  * point.  Just start an async writeback to get the buffers on their way
2345  * to the disk.
2346  *
2347  * This implicitly triggers the writebehind on sync().
2348  */
2349
2350 static void ext4_write_super (struct super_block * sb)
2351 {
2352         if (mutex_trylock(&sb->s_lock) != 0)
2353                 BUG();
2354         sb->s_dirt = 0;
2355 }
2356
2357 static int ext4_sync_fs(struct super_block *sb, int wait)
2358 {
2359         tid_t target;
2360
2361         sb->s_dirt = 0;
2362         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2363                 if (wait)
2364                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2365         }
2366         return 0;
2367 }
2368
2369 /*
2370  * LVM calls this function before a (read-only) snapshot is created.  This
2371  * gives us a chance to flush the journal completely and mark the fs clean.
2372  */
2373 static void ext4_write_super_lockfs(struct super_block *sb)
2374 {
2375         sb->s_dirt = 0;
2376
2377         if (!(sb->s_flags & MS_RDONLY)) {
2378                 journal_t *journal = EXT4_SB(sb)->s_journal;
2379
2380                 /* Now we set up the journal barrier. */
2381                 jbd2_journal_lock_updates(journal);
2382                 jbd2_journal_flush(journal);
2383
2384                 /* Journal blocked and flushed, clear needs_recovery flag. */
2385                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2386                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2387         }
2388 }
2389
2390 /*
2391  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2392  * flag here, even though the filesystem is not technically dirty yet.
2393  */
2394 static void ext4_unlockfs(struct super_block *sb)
2395 {
2396         if (!(sb->s_flags & MS_RDONLY)) {
2397                 lock_super(sb);
2398                 /* Reser the needs_recovery flag before the fs is unlocked. */
2399                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2400                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2401                 unlock_super(sb);
2402                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2403         }
2404 }
2405
2406 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2407 {
2408         struct ext4_super_block * es;
2409         struct ext4_sb_info *sbi = EXT4_SB(sb);
2410         ext4_fsblk_t n_blocks_count = 0;
2411         unsigned long old_sb_flags;
2412         struct ext4_mount_options old_opts;
2413         int err;
2414 #ifdef CONFIG_QUOTA
2415         int i;
2416 #endif
2417
2418         /* Store the original options */
2419         old_sb_flags = sb->s_flags;
2420         old_opts.s_mount_opt = sbi->s_mount_opt;
2421         old_opts.s_resuid = sbi->s_resuid;
2422         old_opts.s_resgid = sbi->s_resgid;
2423         old_opts.s_commit_interval = sbi->s_commit_interval;
2424 #ifdef CONFIG_QUOTA
2425         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2426         for (i = 0; i < MAXQUOTAS; i++)
2427                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2428 #endif
2429
2430         /*
2431          * Allow the "check" option to be passed as a remount option.
2432          */
2433         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2434                 err = -EINVAL;
2435                 goto restore_opts;
2436         }
2437
2438         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2439                 ext4_abort(sb, __FUNCTION__, "Abort forced by user");
2440
2441         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2442                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2443
2444         es = sbi->s_es;
2445
2446         ext4_init_journal_params(sb, sbi->s_journal);
2447
2448         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2449                 n_blocks_count > ext4_blocks_count(es)) {
2450                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2451                         err = -EROFS;
2452                         goto restore_opts;
2453                 }
2454
2455                 if (*flags & MS_RDONLY) {
2456                         /*
2457                          * First of all, the unconditional stuff we have to do
2458                          * to disable replay of the journal when we next remount
2459                          */
2460                         sb->s_flags |= MS_RDONLY;
2461
2462                         /*
2463                          * OK, test if we are remounting a valid rw partition
2464                          * readonly, and if so set the rdonly flag and then
2465                          * mark the partition as valid again.
2466                          */
2467                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2468                             (sbi->s_mount_state & EXT4_VALID_FS))
2469                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
2470
2471                         /*
2472                          * We have to unlock super so that we can wait for
2473                          * transactions.
2474                          */
2475                         unlock_super(sb);
2476                         ext4_mark_recovery_complete(sb, es);
2477                         lock_super(sb);
2478                 } else {
2479                         __le32 ret;
2480                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2481                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2482                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2483                                        "remount RDWR because of unsupported "
2484                                        "optional features (%x).\n",
2485                                        sb->s_id, le32_to_cpu(ret));
2486                                 err = -EROFS;
2487                                 goto restore_opts;
2488                         }
2489
2490                         /*
2491                          * If we have an unprocessed orphan list hanging
2492                          * around from a previously readonly bdev mount,
2493                          * require a full umount/remount for now.
2494                          */
2495                         if (es->s_last_orphan) {
2496                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2497                                        "remount RDWR because of unprocessed "
2498                                        "orphan inode list.  Please "
2499                                        "umount/remount instead.\n",
2500                                        sb->s_id);
2501                                 err = -EINVAL;
2502                                 goto restore_opts;
2503                         }
2504
2505                         /*
2506                          * Mounting a RDONLY partition read-write, so reread
2507                          * and store the current valid flag.  (It may have
2508                          * been changed by e2fsck since we originally mounted
2509                          * the partition.)
2510                          */
2511                         ext4_clear_journal_err(sb, es);
2512                         sbi->s_mount_state = le16_to_cpu(es->s_state);
2513                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2514                                 goto restore_opts;
2515                         if (!ext4_setup_super (sb, es, 0))
2516                                 sb->s_flags &= ~MS_RDONLY;
2517                 }
2518         }
2519 #ifdef CONFIG_QUOTA
2520         /* Release old quota file names */
2521         for (i = 0; i < MAXQUOTAS; i++)
2522                 if (old_opts.s_qf_names[i] &&
2523                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2524                         kfree(old_opts.s_qf_names[i]);
2525 #endif
2526         return 0;
2527 restore_opts:
2528         sb->s_flags = old_sb_flags;
2529         sbi->s_mount_opt = old_opts.s_mount_opt;
2530         sbi->s_resuid = old_opts.s_resuid;
2531         sbi->s_resgid = old_opts.s_resgid;
2532         sbi->s_commit_interval = old_opts.s_commit_interval;
2533 #ifdef CONFIG_QUOTA
2534         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2535         for (i = 0; i < MAXQUOTAS; i++) {
2536                 if (sbi->s_qf_names[i] &&
2537                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2538                         kfree(sbi->s_qf_names[i]);
2539                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2540         }
2541 #endif
2542         return err;
2543 }
2544
2545 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2546 {
2547         struct super_block *sb = dentry->d_sb;
2548         struct ext4_sb_info *sbi = EXT4_SB(sb);
2549         struct ext4_super_block *es = sbi->s_es;
2550         u64 fsid;
2551
2552         if (test_opt(sb, MINIX_DF)) {
2553                 sbi->s_overhead_last = 0;
2554         } else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
2555                 unsigned long ngroups = sbi->s_groups_count, i;
2556                 ext4_fsblk_t overhead = 0;
2557                 smp_rmb();
2558
2559                 /*
2560                  * Compute the overhead (FS structures).  This is constant
2561                  * for a given filesystem unless the number of block groups
2562                  * changes so we cache the previous value until it does.
2563                  */
2564
2565                 /*
2566                  * All of the blocks before first_data_block are
2567                  * overhead
2568                  */
2569                 overhead = le32_to_cpu(es->s_first_data_block);
2570
2571                 /*
2572                  * Add the overhead attributed to the superblock and
2573                  * block group descriptors.  If the sparse superblocks
2574                  * feature is turned on, then not all groups have this.
2575                  */
2576                 for (i = 0; i < ngroups; i++) {
2577                         overhead += ext4_bg_has_super(sb, i) +
2578                                 ext4_bg_num_gdb(sb, i);
2579                         cond_resched();
2580                 }
2581
2582                 /*
2583                  * Every block group has an inode bitmap, a block
2584                  * bitmap, and an inode table.
2585                  */
2586                 overhead += ngroups * (2 + sbi->s_itb_per_group);
2587                 sbi->s_overhead_last = overhead;
2588                 smp_wmb();
2589                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
2590         }
2591
2592         buf->f_type = EXT4_SUPER_MAGIC;
2593         buf->f_bsize = sb->s_blocksize;
2594         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
2595         buf->f_bfree = percpu_counter_sum(&sbi->s_freeblocks_counter);
2596         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
2597         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2598         if (buf->f_bfree < ext4_r_blocks_count(es))
2599                 buf->f_bavail = 0;
2600         buf->f_files = le32_to_cpu(es->s_inodes_count);
2601         buf->f_ffree = percpu_counter_sum(&sbi->s_freeinodes_counter);
2602         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
2603         buf->f_namelen = EXT4_NAME_LEN;
2604         fsid = le64_to_cpup((void *)es->s_uuid) ^
2605                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2606         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2607         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2608         return 0;
2609 }
2610
2611 /* Helper function for writing quotas on sync - we need to start transaction before quota file
2612  * is locked for write. Otherwise the are possible deadlocks:
2613  * Process 1                         Process 2
2614  * ext4_create()                     quota_sync()
2615  *   jbd2_journal_start()                   write_dquot()
2616  *   DQUOT_INIT()                        down(dqio_mutex)
2617  *     down(dqio_mutex)                    jbd2_journal_start()
2618  *
2619  */
2620
2621 #ifdef CONFIG_QUOTA
2622
2623 static inline struct inode *dquot_to_inode(struct dquot *dquot)
2624 {
2625         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
2626 }
2627
2628 static int ext4_dquot_initialize(struct inode *inode, int type)
2629 {
2630         handle_t *handle;
2631         int ret, err;
2632
2633         /* We may create quota structure so we need to reserve enough blocks */
2634         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
2635         if (IS_ERR(handle))
2636                 return PTR_ERR(handle);
2637         ret = dquot_initialize(inode, type);
2638         err = ext4_journal_stop(handle);
2639         if (!ret)
2640                 ret = err;
2641         return ret;
2642 }
2643
2644 static int ext4_dquot_drop(struct inode *inode)
2645 {
2646         handle_t *handle;
2647         int ret, err;
2648
2649         /* We may delete quota structure so we need to reserve enough blocks */
2650         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
2651         if (IS_ERR(handle))
2652                 return PTR_ERR(handle);
2653         ret = dquot_drop(inode);
2654         err = ext4_journal_stop(handle);
2655         if (!ret)
2656                 ret = err;
2657         return ret;
2658 }
2659
2660 static int ext4_write_dquot(struct dquot *dquot)
2661 {
2662         int ret, err;
2663         handle_t *handle;
2664         struct inode *inode;
2665
2666         inode = dquot_to_inode(dquot);
2667         handle = ext4_journal_start(inode,
2668                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
2669         if (IS_ERR(handle))
2670                 return PTR_ERR(handle);
2671         ret = dquot_commit(dquot);
2672         err = ext4_journal_stop(handle);
2673         if (!ret)
2674                 ret = err;
2675         return ret;
2676 }
2677
2678 static int ext4_acquire_dquot(struct dquot *dquot)
2679 {
2680         int ret, err;
2681         handle_t *handle;
2682
2683         handle = ext4_journal_start(dquot_to_inode(dquot),
2684                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
2685         if (IS_ERR(handle))
2686                 return PTR_ERR(handle);
2687         ret = dquot_acquire(dquot);
2688         err = ext4_journal_stop(handle);
2689         if (!ret)
2690                 ret = err;
2691         return ret;
2692 }
2693
2694 static int ext4_release_dquot(struct dquot *dquot)
2695 {
2696         int ret, err;
2697         handle_t *handle;
2698
2699         handle = ext4_journal_start(dquot_to_inode(dquot),
2700                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
2701         if (IS_ERR(handle))
2702                 return PTR_ERR(handle);
2703         ret = dquot_release(dquot);
2704         err = ext4_journal_stop(handle);
2705         if (!ret)
2706                 ret = err;
2707         return ret;
2708 }
2709
2710 static int ext4_mark_dquot_dirty(struct dquot *dquot)
2711 {
2712         /* Are we journalling quotas? */
2713         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
2714             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
2715                 dquot_mark_dquot_dirty(dquot);
2716                 return ext4_write_dquot(dquot);
2717         } else {
2718                 return dquot_mark_dquot_dirty(dquot);
2719         }
2720 }
2721
2722 static int ext4_write_info(struct super_block *sb, int type)
2723 {
2724         int ret, err;
2725         handle_t *handle;
2726
2727         /* Data block + inode block */
2728         handle = ext4_journal_start(sb->s_root->d_inode, 2);
2729         if (IS_ERR(handle))
2730                 return PTR_ERR(handle);
2731         ret = dquot_commit_info(sb, type);
2732         err = ext4_journal_stop(handle);
2733         if (!ret)
2734                 ret = err;
2735         return ret;
2736 }
2737
2738 /*
2739  * Turn on quotas during mount time - we need to find
2740  * the quota file and such...
2741  */
2742 static int ext4_quota_on_mount(struct super_block *sb, int type)
2743 {
2744         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
2745                         EXT4_SB(sb)->s_jquota_fmt, type);
2746 }
2747
2748 /*
2749  * Standard function to be called on quota_on
2750  */
2751 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
2752                          char *path)
2753 {
2754         int err;
2755         struct nameidata nd;
2756
2757         if (!test_opt(sb, QUOTA))
2758                 return -EINVAL;
2759         /* Not journalling quota? */
2760         if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
2761             !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
2762                 return vfs_quota_on(sb, type, format_id, path);
2763         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
2764         if (err)
2765                 return err;
2766         /* Quotafile not on the same filesystem? */
2767         if (nd.mnt->mnt_sb != sb) {
2768                 path_release(&nd);
2769                 return -EXDEV;
2770         }
2771         /* Quotafile not of fs root? */
2772         if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
2773                 printk(KERN_WARNING
2774                         "EXT4-fs: Quota file not on filesystem root. "
2775                         "Journalled quota will not work.\n");
2776         path_release(&nd);
2777         return vfs_quota_on(sb, type, format_id, path);
2778 }
2779
2780 /* Read data from quotafile - avoid pagecache and such because we cannot afford
2781  * acquiring the locks... As quota files are never truncated and quota code
2782  * itself serializes the operations (and noone else should touch the files)
2783  * we don't have to be afraid of races */
2784 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
2785                                size_t len, loff_t off)
2786 {
2787         struct inode *inode = sb_dqopt(sb)->files[type];
2788         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2789         int err = 0;
2790         int offset = off & (sb->s_blocksize - 1);
2791         int tocopy;
2792         size_t toread;
2793         struct buffer_head *bh;
2794         loff_t i_size = i_size_read(inode);
2795
2796         if (off > i_size)
2797                 return 0;
2798         if (off+len > i_size)
2799                 len = i_size-off;
2800         toread = len;
2801         while (toread > 0) {
2802                 tocopy = sb->s_blocksize - offset < toread ?
2803                                 sb->s_blocksize - offset : toread;
2804                 bh = ext4_bread(NULL, inode, blk, 0, &err);
2805                 if (err)
2806                         return err;
2807                 if (!bh)        /* A hole? */
2808                         memset(data, 0, tocopy);
2809                 else
2810                         memcpy(data, bh->b_data+offset, tocopy);
2811                 brelse(bh);
2812                 offset = 0;
2813                 toread -= tocopy;
2814                 data += tocopy;
2815                 blk++;
2816         }
2817         return len;
2818 }
2819
2820 /* Write to quotafile (we know the transaction is already started and has
2821  * enough credits) */
2822 static ssize_t ext4_quota_write(struct super_block *sb, int type,
2823                                 const char *data, size_t len, loff_t off)
2824 {
2825         struct inode *inode = sb_dqopt(sb)->files[type];
2826         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2827         int err = 0;
2828         int offset = off & (sb->s_blocksize - 1);
2829         int tocopy;
2830         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
2831         size_t towrite = len;
2832         struct buffer_head *bh;
2833         handle_t *handle = journal_current_handle();
2834
2835         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2836         while (towrite > 0) {
2837                 tocopy = sb->s_blocksize - offset < towrite ?
2838                                 sb->s_blocksize - offset : towrite;
2839                 bh = ext4_bread(handle, inode, blk, 1, &err);
2840                 if (!bh)
2841                         goto out;
2842                 if (journal_quota) {
2843                         err = ext4_journal_get_write_access(handle, bh);
2844                         if (err) {
2845                                 brelse(bh);
2846                                 goto out;
2847                         }
2848                 }
2849                 lock_buffer(bh);
2850                 memcpy(bh->b_data+offset, data, tocopy);
2851                 flush_dcache_page(bh->b_page);
2852                 unlock_buffer(bh);
2853                 if (journal_quota)
2854                         err = ext4_journal_dirty_metadata(handle, bh);
2855                 else {
2856                         /* Always do at least ordered writes for quotas */
2857                         err = ext4_journal_dirty_data(handle, bh);
2858                         mark_buffer_dirty(bh);
2859                 }
2860                 brelse(bh);
2861                 if (err)
2862                         goto out;
2863                 offset = 0;
2864                 towrite -= tocopy;
2865                 data += tocopy;
2866                 blk++;
2867         }
2868 out:
2869         if (len == towrite)
2870                 return err;
2871         if (inode->i_size < off+len-towrite) {
2872                 i_size_write(inode, off+len-towrite);
2873                 EXT4_I(inode)->i_disksize = inode->i_size;
2874         }
2875         inode->i_version++;
2876         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2877         ext4_mark_inode_dirty(handle, inode);
2878         mutex_unlock(&inode->i_mutex);
2879         return len - towrite;
2880 }
2881
2882 #endif
2883
2884 static int ext4_get_sb(struct file_system_type *fs_type,
2885         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
2886 {
2887         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
2888 }
2889
2890 static struct file_system_type ext4dev_fs_type = {
2891         .owner          = THIS_MODULE,
2892         .name           = "ext4dev",
2893         .get_sb         = ext4_get_sb,
2894         .kill_sb        = kill_block_super,
2895         .fs_flags       = FS_REQUIRES_DEV,
2896 };
2897
2898 static int __init init_ext4_fs(void)
2899 {
2900         int err = init_ext4_xattr();
2901         if (err)
2902                 return err;
2903         err = init_inodecache();
2904         if (err)
2905                 goto out1;
2906         err = register_filesystem(&ext4dev_fs_type);
2907         if (err)
2908                 goto out;
2909         return 0;
2910 out:
2911         destroy_inodecache();
2912 out1:
2913         exit_ext4_xattr();
2914         return err;
2915 }
2916
2917 static void __exit exit_ext4_fs(void)
2918 {
2919         unregister_filesystem(&ext4dev_fs_type);
2920         destroy_inodecache();
2921         exit_ext4_xattr();
2922 }
2923
2924 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
2925 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
2926 MODULE_LICENSE("GPL");
2927 module_init(init_ext4_fs)
2928 module_exit(exit_ext4_fs)