61c4718e4a5391239191e2043c3a6a3e56e0f0c9
[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/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38
39 #include <asm/uaccess.h>
40
41 #include "xattr.h"
42 #include "acl.h"
43 #include "namei.h"
44
45 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
46                              unsigned long journal_devnum);
47 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
48                                unsigned int);
49 static void ext4_commit_super (struct super_block * sb,
50                                struct ext4_super_block * es,
51                                int sync);
52 static void ext4_mark_recovery_complete(struct super_block * sb,
53                                         struct ext4_super_block * es);
54 static void ext4_clear_journal_err(struct super_block * sb,
55                                    struct ext4_super_block * es);
56 static int ext4_sync_fs(struct super_block *sb, int wait);
57 static const char *ext4_decode_error(struct super_block * sb, int errno,
58                                      char nbuf[16]);
59 static int ext4_remount (struct super_block * sb, int * flags, char * data);
60 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
61 static void ext4_unlockfs(struct super_block *sb);
62 static void ext4_write_super (struct super_block * sb);
63 static void ext4_write_super_lockfs(struct super_block *sb);
64
65
66 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
67                                struct ext4_group_desc *bg)
68 {
69         return le32_to_cpu(bg->bg_block_bitmap) |
70                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
71                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
72 }
73
74 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
75                                struct ext4_group_desc *bg)
76 {
77         return le32_to_cpu(bg->bg_inode_bitmap) |
78                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
79                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
80 }
81
82 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
83                               struct ext4_group_desc *bg)
84 {
85         return le32_to_cpu(bg->bg_inode_table) |
86                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
87                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
88 }
89
90 void ext4_block_bitmap_set(struct super_block *sb,
91                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
92 {
93         bg->bg_block_bitmap = cpu_to_le32((u32)blk);
94         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
95                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
96 }
97
98 void ext4_inode_bitmap_set(struct super_block *sb,
99                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
100 {
101         bg->bg_inode_bitmap  = cpu_to_le32((u32)blk);
102         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
103                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
104 }
105
106 void ext4_inode_table_set(struct super_block *sb,
107                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
108 {
109         bg->bg_inode_table = cpu_to_le32((u32)blk);
110         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
111                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
112 }
113
114 /*
115  * Wrappers for jbd2_journal_start/end.
116  *
117  * The only special thing we need to do here is to make sure that all
118  * journal_end calls result in the superblock being marked dirty, so
119  * that sync() will call the filesystem's write_super callback if
120  * appropriate.
121  */
122 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
123 {
124         journal_t *journal;
125
126         if (sb->s_flags & MS_RDONLY)
127                 return ERR_PTR(-EROFS);
128
129         /* Special case here: if the journal has aborted behind our
130          * backs (eg. EIO in the commit thread), then we still need to
131          * take the FS itself readonly cleanly. */
132         journal = EXT4_SB(sb)->s_journal;
133         if (is_journal_aborted(journal)) {
134                 ext4_abort(sb, __FUNCTION__,
135                            "Detected aborted journal");
136                 return ERR_PTR(-EROFS);
137         }
138
139         return jbd2_journal_start(journal, nblocks);
140 }
141
142 /*
143  * The only special thing we need to do here is to make sure that all
144  * jbd2_journal_stop calls result in the superblock being marked dirty, so
145  * that sync() will call the filesystem's write_super callback if
146  * appropriate.
147  */
148 int __ext4_journal_stop(const char *where, handle_t *handle)
149 {
150         struct super_block *sb;
151         int err;
152         int rc;
153
154         sb = handle->h_transaction->t_journal->j_private;
155         err = handle->h_err;
156         rc = jbd2_journal_stop(handle);
157
158         if (!err)
159                 err = rc;
160         if (err)
161                 __ext4_std_error(sb, where, err);
162         return err;
163 }
164
165 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
166                 struct buffer_head *bh, handle_t *handle, int err)
167 {
168         char nbuf[16];
169         const char *errstr = ext4_decode_error(NULL, err, nbuf);
170
171         if (bh)
172                 BUFFER_TRACE(bh, "abort");
173
174         if (!handle->h_err)
175                 handle->h_err = err;
176
177         if (is_handle_aborted(handle))
178                 return;
179
180         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
181                caller, errstr, err_fn);
182
183         jbd2_journal_abort_handle(handle);
184 }
185
186 /* Deal with the reporting of failure conditions on a filesystem such as
187  * inconsistencies detected or read IO failures.
188  *
189  * On ext2, we can store the error state of the filesystem in the
190  * superblock.  That is not possible on ext4, because we may have other
191  * write ordering constraints on the superblock which prevent us from
192  * writing it out straight away; and given that the journal is about to
193  * be aborted, we can't rely on the current, or future, transactions to
194  * write out the superblock safely.
195  *
196  * We'll just use the jbd2_journal_abort() error code to record an error in
197  * the journal instead.  On recovery, the journal will compain about
198  * that error until we've noted it down and cleared it.
199  */
200
201 static void ext4_handle_error(struct super_block *sb)
202 {
203         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
204
205         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
206         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
207
208         if (sb->s_flags & MS_RDONLY)
209                 return;
210
211         if (!test_opt (sb, ERRORS_CONT)) {
212                 journal_t *journal = EXT4_SB(sb)->s_journal;
213
214                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
215                 if (journal)
216                         jbd2_journal_abort(journal, -EIO);
217         }
218         if (test_opt (sb, ERRORS_RO)) {
219                 printk (KERN_CRIT "Remounting filesystem read-only\n");
220                 sb->s_flags |= MS_RDONLY;
221         }
222         ext4_commit_super(sb, es, 1);
223         if (test_opt(sb, ERRORS_PANIC))
224                 panic("EXT4-fs (device %s): panic forced after error\n",
225                         sb->s_id);
226 }
227
228 void ext4_error (struct super_block * sb, const char * function,
229                  const char * fmt, ...)
230 {
231         va_list args;
232
233         va_start(args, fmt);
234         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
235         vprintk(fmt, args);
236         printk("\n");
237         va_end(args);
238
239         ext4_handle_error(sb);
240 }
241
242 static const char *ext4_decode_error(struct super_block * sb, int errno,
243                                      char nbuf[16])
244 {
245         char *errstr = NULL;
246
247         switch (errno) {
248         case -EIO:
249                 errstr = "IO failure";
250                 break;
251         case -ENOMEM:
252                 errstr = "Out of memory";
253                 break;
254         case -EROFS:
255                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
256                         errstr = "Journal has aborted";
257                 else
258                         errstr = "Readonly filesystem";
259                 break;
260         default:
261                 /* If the caller passed in an extra buffer for unknown
262                  * errors, textualise them now.  Else we just return
263                  * NULL. */
264                 if (nbuf) {
265                         /* Check for truncated error codes... */
266                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
267                                 errstr = nbuf;
268                 }
269                 break;
270         }
271
272         return errstr;
273 }
274
275 /* __ext4_std_error decodes expected errors from journaling functions
276  * automatically and invokes the appropriate error response.  */
277
278 void __ext4_std_error (struct super_block * sb, const char * function,
279                        int errno)
280 {
281         char nbuf[16];
282         const char *errstr;
283
284         /* Special case: if the error is EROFS, and we're not already
285          * inside a transaction, then there's really no point in logging
286          * an error. */
287         if (errno == -EROFS && journal_current_handle() == NULL &&
288             (sb->s_flags & MS_RDONLY))
289                 return;
290
291         errstr = ext4_decode_error(sb, errno, nbuf);
292         printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
293                 sb->s_id, function, errstr);
294
295         ext4_handle_error(sb);
296 }
297
298 /*
299  * ext4_abort is a much stronger failure handler than ext4_error.  The
300  * abort function may be used to deal with unrecoverable failures such
301  * as journal IO errors or ENOMEM at a critical moment in log management.
302  *
303  * We unconditionally force the filesystem into an ABORT|READONLY state,
304  * unless the error response on the fs has been set to panic in which
305  * case we take the easy way out and panic immediately.
306  */
307
308 void ext4_abort (struct super_block * sb, const char * function,
309                  const char * fmt, ...)
310 {
311         va_list args;
312
313         printk (KERN_CRIT "ext4_abort called.\n");
314
315         va_start(args, fmt);
316         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
317         vprintk(fmt, args);
318         printk("\n");
319         va_end(args);
320
321         if (test_opt(sb, ERRORS_PANIC))
322                 panic("EXT4-fs panic from previous error\n");
323
324         if (sb->s_flags & MS_RDONLY)
325                 return;
326
327         printk(KERN_CRIT "Remounting filesystem read-only\n");
328         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
329         sb->s_flags |= MS_RDONLY;
330         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
331         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
332 }
333
334 void ext4_warning (struct super_block * sb, const char * function,
335                    const char * fmt, ...)
336 {
337         va_list args;
338
339         va_start(args, fmt);
340         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
341                sb->s_id, function);
342         vprintk(fmt, args);
343         printk("\n");
344         va_end(args);
345 }
346
347 void ext4_update_dynamic_rev(struct super_block *sb)
348 {
349         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
350
351         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
352                 return;
353
354         ext4_warning(sb, __FUNCTION__,
355                      "updating to rev %d because of new feature flag, "
356                      "running e2fsck is recommended",
357                      EXT4_DYNAMIC_REV);
358
359         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
360         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
361         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
362         /* leave es->s_feature_*compat flags alone */
363         /* es->s_uuid will be set by e2fsck if empty */
364
365         /*
366          * The rest of the superblock fields should be zero, and if not it
367          * means they are likely already in use, so leave them alone.  We
368          * can leave it up to e2fsck to clean up any inconsistencies there.
369          */
370 }
371
372 /*
373  * Open the external journal device
374  */
375 static struct block_device *ext4_blkdev_get(dev_t dev)
376 {
377         struct block_device *bdev;
378         char b[BDEVNAME_SIZE];
379
380         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
381         if (IS_ERR(bdev))
382                 goto fail;
383         return bdev;
384
385 fail:
386         printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
387                         __bdevname(dev, b), PTR_ERR(bdev));
388         return NULL;
389 }
390
391 /*
392  * Release the journal device
393  */
394 static int ext4_blkdev_put(struct block_device *bdev)
395 {
396         bd_release(bdev);
397         return blkdev_put(bdev);
398 }
399
400 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
401 {
402         struct block_device *bdev;
403         int ret = -ENODEV;
404
405         bdev = sbi->journal_bdev;
406         if (bdev) {
407                 ret = ext4_blkdev_put(bdev);
408                 sbi->journal_bdev = NULL;
409         }
410         return ret;
411 }
412
413 static inline struct inode *orphan_list_entry(struct list_head *l)
414 {
415         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
416 }
417
418 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
419 {
420         struct list_head *l;
421
422         printk(KERN_ERR "sb orphan head is %d\n",
423                le32_to_cpu(sbi->s_es->s_last_orphan));
424
425         printk(KERN_ERR "sb_info orphan list:\n");
426         list_for_each(l, &sbi->s_orphan) {
427                 struct inode *inode = orphan_list_entry(l);
428                 printk(KERN_ERR "  "
429                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
430                        inode->i_sb->s_id, inode->i_ino, inode,
431                        inode->i_mode, inode->i_nlink,
432                        NEXT_ORPHAN(inode));
433         }
434 }
435
436 static void ext4_put_super (struct super_block * sb)
437 {
438         struct ext4_sb_info *sbi = EXT4_SB(sb);
439         struct ext4_super_block *es = sbi->s_es;
440         int i;
441
442         ext4_ext_release(sb);
443         ext4_xattr_put_super(sb);
444         jbd2_journal_destroy(sbi->s_journal);
445         if (!(sb->s_flags & MS_RDONLY)) {
446                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
447                 es->s_state = cpu_to_le16(sbi->s_mount_state);
448                 BUFFER_TRACE(sbi->s_sbh, "marking dirty");
449                 mark_buffer_dirty(sbi->s_sbh);
450                 ext4_commit_super(sb, es, 1);
451         }
452
453         for (i = 0; i < sbi->s_gdb_count; i++)
454                 brelse(sbi->s_group_desc[i]);
455         kfree(sbi->s_group_desc);
456         percpu_counter_destroy(&sbi->s_freeblocks_counter);
457         percpu_counter_destroy(&sbi->s_freeinodes_counter);
458         percpu_counter_destroy(&sbi->s_dirs_counter);
459         brelse(sbi->s_sbh);
460 #ifdef CONFIG_QUOTA
461         for (i = 0; i < MAXQUOTAS; i++)
462                 kfree(sbi->s_qf_names[i]);
463 #endif
464
465         /* Debugging code just in case the in-memory inode orphan list
466          * isn't empty.  The on-disk one can be non-empty if we've
467          * detected an error and taken the fs readonly, but the
468          * in-memory list had better be clean by this point. */
469         if (!list_empty(&sbi->s_orphan))
470                 dump_orphan_list(sb, sbi);
471         J_ASSERT(list_empty(&sbi->s_orphan));
472
473         invalidate_bdev(sb->s_bdev, 0);
474         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
475                 /*
476                  * Invalidate the journal device's buffers.  We don't want them
477                  * floating about in memory - the physical journal device may
478                  * hotswapped, and it breaks the `ro-after' testing code.
479                  */
480                 sync_blockdev(sbi->journal_bdev);
481                 invalidate_bdev(sbi->journal_bdev, 0);
482                 ext4_blkdev_remove(sbi);
483         }
484         sb->s_fs_info = NULL;
485         kfree(sbi);
486         return;
487 }
488
489 static struct kmem_cache *ext4_inode_cachep;
490
491 /*
492  * Called inside transaction, so use GFP_NOFS
493  */
494 static struct inode *ext4_alloc_inode(struct super_block *sb)
495 {
496         struct ext4_inode_info *ei;
497
498         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
499         if (!ei)
500                 return NULL;
501 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
502         ei->i_acl = EXT4_ACL_NOT_CACHED;
503         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
504 #endif
505         ei->i_block_alloc_info = NULL;
506         ei->vfs_inode.i_version = 1;
507         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
508         return &ei->vfs_inode;
509 }
510
511 static void ext4_destroy_inode(struct inode *inode)
512 {
513         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
514 }
515
516 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
517 {
518         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
519
520         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
521             SLAB_CTOR_CONSTRUCTOR) {
522                 INIT_LIST_HEAD(&ei->i_orphan);
523 #ifdef CONFIG_EXT4DEV_FS_XATTR
524                 init_rwsem(&ei->xattr_sem);
525 #endif
526                 mutex_init(&ei->truncate_mutex);
527                 inode_init_once(&ei->vfs_inode);
528         }
529 }
530
531 static int init_inodecache(void)
532 {
533         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
534                                              sizeof(struct ext4_inode_info),
535                                              0, (SLAB_RECLAIM_ACCOUNT|
536                                                 SLAB_MEM_SPREAD),
537                                              init_once, NULL);
538         if (ext4_inode_cachep == NULL)
539                 return -ENOMEM;
540         return 0;
541 }
542
543 static void destroy_inodecache(void)
544 {
545         kmem_cache_destroy(ext4_inode_cachep);
546 }
547
548 static void ext4_clear_inode(struct inode *inode)
549 {
550         struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
551 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
552         if (EXT4_I(inode)->i_acl &&
553                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
554                 posix_acl_release(EXT4_I(inode)->i_acl);
555                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
556         }
557         if (EXT4_I(inode)->i_default_acl &&
558                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
559                 posix_acl_release(EXT4_I(inode)->i_default_acl);
560                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
561         }
562 #endif
563         ext4_discard_reservation(inode);
564         EXT4_I(inode)->i_block_alloc_info = NULL;
565         if (unlikely(rsv))
566                 kfree(rsv);
567 }
568
569 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
570 {
571 #if defined(CONFIG_QUOTA)
572         struct ext4_sb_info *sbi = EXT4_SB(sb);
573
574         if (sbi->s_jquota_fmt)
575                 seq_printf(seq, ",jqfmt=%s",
576                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
577
578         if (sbi->s_qf_names[USRQUOTA])
579                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
580
581         if (sbi->s_qf_names[GRPQUOTA])
582                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
583
584         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
585                 seq_puts(seq, ",usrquota");
586
587         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
588                 seq_puts(seq, ",grpquota");
589 #endif
590 }
591
592 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
593 {
594         struct super_block *sb = vfs->mnt_sb;
595
596         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
597                 seq_puts(seq, ",data=journal");
598         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
599                 seq_puts(seq, ",data=ordered");
600         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
601                 seq_puts(seq, ",data=writeback");
602
603         ext4_show_quota_options(seq, sb);
604
605         return 0;
606 }
607
608
609 static struct dentry *ext4_get_dentry(struct super_block *sb, void *vobjp)
610 {
611         __u32 *objp = vobjp;
612         unsigned long ino = objp[0];
613         __u32 generation = objp[1];
614         struct inode *inode;
615         struct dentry *result;
616
617         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
618                 return ERR_PTR(-ESTALE);
619         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
620                 return ERR_PTR(-ESTALE);
621
622         /* iget isn't really right if the inode is currently unallocated!!
623          *
624          * ext4_read_inode will return a bad_inode if the inode had been
625          * deleted, so we should be safe.
626          *
627          * Currently we don't know the generation for parent directory, so
628          * a generation of 0 means "accept any"
629          */
630         inode = iget(sb, ino);
631         if (inode == NULL)
632                 return ERR_PTR(-ENOMEM);
633         if (is_bad_inode(inode) ||
634             (generation && inode->i_generation != generation)) {
635                 iput(inode);
636                 return ERR_PTR(-ESTALE);
637         }
638         /* now to find a dentry.
639          * If possible, get a well-connected one
640          */
641         result = d_alloc_anon(inode);
642         if (!result) {
643                 iput(inode);
644                 return ERR_PTR(-ENOMEM);
645         }
646         return result;
647 }
648
649 #ifdef CONFIG_QUOTA
650 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
651 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
652
653 static int ext4_dquot_initialize(struct inode *inode, int type);
654 static int ext4_dquot_drop(struct inode *inode);
655 static int ext4_write_dquot(struct dquot *dquot);
656 static int ext4_acquire_dquot(struct dquot *dquot);
657 static int ext4_release_dquot(struct dquot *dquot);
658 static int ext4_mark_dquot_dirty(struct dquot *dquot);
659 static int ext4_write_info(struct super_block *sb, int type);
660 static int ext4_quota_on(struct super_block *sb, int type, int format_id, char *path);
661 static int ext4_quota_on_mount(struct super_block *sb, int type);
662 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
663                                size_t len, loff_t off);
664 static ssize_t ext4_quota_write(struct super_block *sb, int type,
665                                 const char *data, size_t len, loff_t off);
666
667 static struct dquot_operations ext4_quota_operations = {
668         .initialize     = ext4_dquot_initialize,
669         .drop           = ext4_dquot_drop,
670         .alloc_space    = dquot_alloc_space,
671         .alloc_inode    = dquot_alloc_inode,
672         .free_space     = dquot_free_space,
673         .free_inode     = dquot_free_inode,
674         .transfer       = dquot_transfer,
675         .write_dquot    = ext4_write_dquot,
676         .acquire_dquot  = ext4_acquire_dquot,
677         .release_dquot  = ext4_release_dquot,
678         .mark_dirty     = ext4_mark_dquot_dirty,
679         .write_info     = ext4_write_info
680 };
681
682 static struct quotactl_ops ext4_qctl_operations = {
683         .quota_on       = ext4_quota_on,
684         .quota_off      = vfs_quota_off,
685         .quota_sync     = vfs_quota_sync,
686         .get_info       = vfs_get_dqinfo,
687         .set_info       = vfs_set_dqinfo,
688         .get_dqblk      = vfs_get_dqblk,
689         .set_dqblk      = vfs_set_dqblk
690 };
691 #endif
692
693 static const struct super_operations ext4_sops = {
694         .alloc_inode    = ext4_alloc_inode,
695         .destroy_inode  = ext4_destroy_inode,
696         .read_inode     = ext4_read_inode,
697         .write_inode    = ext4_write_inode,
698         .dirty_inode    = ext4_dirty_inode,
699         .delete_inode   = ext4_delete_inode,
700         .put_super      = ext4_put_super,
701         .write_super    = ext4_write_super,
702         .sync_fs        = ext4_sync_fs,
703         .write_super_lockfs = ext4_write_super_lockfs,
704         .unlockfs       = ext4_unlockfs,
705         .statfs         = ext4_statfs,
706         .remount_fs     = ext4_remount,
707         .clear_inode    = ext4_clear_inode,
708         .show_options   = ext4_show_options,
709 #ifdef CONFIG_QUOTA
710         .quota_read     = ext4_quota_read,
711         .quota_write    = ext4_quota_write,
712 #endif
713 };
714
715 static struct export_operations ext4_export_ops = {
716         .get_parent = ext4_get_parent,
717         .get_dentry = ext4_get_dentry,
718 };
719
720 enum {
721         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
722         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
723         Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
724         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
725         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
726         Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
727         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
728         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
729         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
730         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
731         Opt_grpquota, Opt_extents,
732 };
733
734 static match_table_t tokens = {
735         {Opt_bsd_df, "bsddf"},
736         {Opt_minix_df, "minixdf"},
737         {Opt_grpid, "grpid"},
738         {Opt_grpid, "bsdgroups"},
739         {Opt_nogrpid, "nogrpid"},
740         {Opt_nogrpid, "sysvgroups"},
741         {Opt_resgid, "resgid=%u"},
742         {Opt_resuid, "resuid=%u"},
743         {Opt_sb, "sb=%u"},
744         {Opt_err_cont, "errors=continue"},
745         {Opt_err_panic, "errors=panic"},
746         {Opt_err_ro, "errors=remount-ro"},
747         {Opt_nouid32, "nouid32"},
748         {Opt_nocheck, "nocheck"},
749         {Opt_nocheck, "check=none"},
750         {Opt_debug, "debug"},
751         {Opt_oldalloc, "oldalloc"},
752         {Opt_orlov, "orlov"},
753         {Opt_user_xattr, "user_xattr"},
754         {Opt_nouser_xattr, "nouser_xattr"},
755         {Opt_acl, "acl"},
756         {Opt_noacl, "noacl"},
757         {Opt_reservation, "reservation"},
758         {Opt_noreservation, "noreservation"},
759         {Opt_noload, "noload"},
760         {Opt_nobh, "nobh"},
761         {Opt_bh, "bh"},
762         {Opt_commit, "commit=%u"},
763         {Opt_journal_update, "journal=update"},
764         {Opt_journal_inum, "journal=%u"},
765         {Opt_journal_dev, "journal_dev=%u"},
766         {Opt_abort, "abort"},
767         {Opt_data_journal, "data=journal"},
768         {Opt_data_ordered, "data=ordered"},
769         {Opt_data_writeback, "data=writeback"},
770         {Opt_offusrjquota, "usrjquota="},
771         {Opt_usrjquota, "usrjquota=%s"},
772         {Opt_offgrpjquota, "grpjquota="},
773         {Opt_grpjquota, "grpjquota=%s"},
774         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
775         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
776         {Opt_grpquota, "grpquota"},
777         {Opt_noquota, "noquota"},
778         {Opt_quota, "quota"},
779         {Opt_usrquota, "usrquota"},
780         {Opt_barrier, "barrier=%u"},
781         {Opt_extents, "extents"},
782         {Opt_err, NULL},
783         {Opt_resize, "resize"},
784 };
785
786 static ext4_fsblk_t get_sb_block(void **data)
787 {
788         ext4_fsblk_t    sb_block;
789         char            *options = (char *) *data;
790
791         if (!options || strncmp(options, "sb=", 3) != 0)
792                 return 1;       /* Default location */
793         options += 3;
794         /*todo: use simple_strtoll with >32bit ext4 */
795         sb_block = simple_strtoul(options, &options, 0);
796         if (*options && *options != ',') {
797                 printk("EXT4-fs: Invalid sb specification: %s\n",
798                        (char *) *data);
799                 return 1;
800         }
801         if (*options == ',')
802                 options++;
803         *data = (void *) options;
804         return sb_block;
805 }
806
807 static int parse_options (char *options, struct super_block *sb,
808                           unsigned int *inum, unsigned long *journal_devnum,
809                           ext4_fsblk_t *n_blocks_count, int is_remount)
810 {
811         struct ext4_sb_info *sbi = EXT4_SB(sb);
812         char * p;
813         substring_t args[MAX_OPT_ARGS];
814         int data_opt = 0;
815         int option;
816 #ifdef CONFIG_QUOTA
817         int qtype;
818         char *qname;
819 #endif
820
821         if (!options)
822                 return 1;
823
824         while ((p = strsep (&options, ",")) != NULL) {
825                 int token;
826                 if (!*p)
827                         continue;
828
829                 token = match_token(p, tokens, args);
830                 switch (token) {
831                 case Opt_bsd_df:
832                         clear_opt (sbi->s_mount_opt, MINIX_DF);
833                         break;
834                 case Opt_minix_df:
835                         set_opt (sbi->s_mount_opt, MINIX_DF);
836                         break;
837                 case Opt_grpid:
838                         set_opt (sbi->s_mount_opt, GRPID);
839                         break;
840                 case Opt_nogrpid:
841                         clear_opt (sbi->s_mount_opt, GRPID);
842                         break;
843                 case Opt_resuid:
844                         if (match_int(&args[0], &option))
845                                 return 0;
846                         sbi->s_resuid = option;
847                         break;
848                 case Opt_resgid:
849                         if (match_int(&args[0], &option))
850                                 return 0;
851                         sbi->s_resgid = option;
852                         break;
853                 case Opt_sb:
854                         /* handled by get_sb_block() instead of here */
855                         /* *sb_block = match_int(&args[0]); */
856                         break;
857                 case Opt_err_panic:
858                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
859                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
860                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
861                         break;
862                 case Opt_err_ro:
863                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
864                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
865                         set_opt (sbi->s_mount_opt, ERRORS_RO);
866                         break;
867                 case Opt_err_cont:
868                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
869                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
870                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
871                         break;
872                 case Opt_nouid32:
873                         set_opt (sbi->s_mount_opt, NO_UID32);
874                         break;
875                 case Opt_nocheck:
876                         clear_opt (sbi->s_mount_opt, CHECK);
877                         break;
878                 case Opt_debug:
879                         set_opt (sbi->s_mount_opt, DEBUG);
880                         break;
881                 case Opt_oldalloc:
882                         set_opt (sbi->s_mount_opt, OLDALLOC);
883                         break;
884                 case Opt_orlov:
885                         clear_opt (sbi->s_mount_opt, OLDALLOC);
886                         break;
887 #ifdef CONFIG_EXT4DEV_FS_XATTR
888                 case Opt_user_xattr:
889                         set_opt (sbi->s_mount_opt, XATTR_USER);
890                         break;
891                 case Opt_nouser_xattr:
892                         clear_opt (sbi->s_mount_opt, XATTR_USER);
893                         break;
894 #else
895                 case Opt_user_xattr:
896                 case Opt_nouser_xattr:
897                         printk("EXT4 (no)user_xattr options not supported\n");
898                         break;
899 #endif
900 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
901                 case Opt_acl:
902                         set_opt(sbi->s_mount_opt, POSIX_ACL);
903                         break;
904                 case Opt_noacl:
905                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
906                         break;
907 #else
908                 case Opt_acl:
909                 case Opt_noacl:
910                         printk("EXT4 (no)acl options not supported\n");
911                         break;
912 #endif
913                 case Opt_reservation:
914                         set_opt(sbi->s_mount_opt, RESERVATION);
915                         break;
916                 case Opt_noreservation:
917                         clear_opt(sbi->s_mount_opt, RESERVATION);
918                         break;
919                 case Opt_journal_update:
920                         /* @@@ FIXME */
921                         /* Eventually we will want to be able to create
922                            a journal file here.  For now, only allow the
923                            user to specify an existing inode to be the
924                            journal file. */
925                         if (is_remount) {
926                                 printk(KERN_ERR "EXT4-fs: cannot specify "
927                                        "journal on remount\n");
928                                 return 0;
929                         }
930                         set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
931                         break;
932                 case Opt_journal_inum:
933                         if (is_remount) {
934                                 printk(KERN_ERR "EXT4-fs: cannot specify "
935                                        "journal on remount\n");
936                                 return 0;
937                         }
938                         if (match_int(&args[0], &option))
939                                 return 0;
940                         *inum = option;
941                         break;
942                 case Opt_journal_dev:
943                         if (is_remount) {
944                                 printk(KERN_ERR "EXT4-fs: cannot specify "
945                                        "journal on remount\n");
946                                 return 0;
947                         }
948                         if (match_int(&args[0], &option))
949                                 return 0;
950                         *journal_devnum = option;
951                         break;
952                 case Opt_noload:
953                         set_opt (sbi->s_mount_opt, NOLOAD);
954                         break;
955                 case Opt_commit:
956                         if (match_int(&args[0], &option))
957                                 return 0;
958                         if (option < 0)
959                                 return 0;
960                         if (option == 0)
961                                 option = JBD_DEFAULT_MAX_COMMIT_AGE;
962                         sbi->s_commit_interval = HZ * option;
963                         break;
964                 case Opt_data_journal:
965                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
966                         goto datacheck;
967                 case Opt_data_ordered:
968                         data_opt = EXT4_MOUNT_ORDERED_DATA;
969                         goto datacheck;
970                 case Opt_data_writeback:
971                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
972                 datacheck:
973                         if (is_remount) {
974                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
975                                                 != data_opt) {
976                                         printk(KERN_ERR
977                                                 "EXT4-fs: cannot change data "
978                                                 "mode on remount\n");
979                                         return 0;
980                                 }
981                         } else {
982                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
983                                 sbi->s_mount_opt |= data_opt;
984                         }
985                         break;
986 #ifdef CONFIG_QUOTA
987                 case Opt_usrjquota:
988                         qtype = USRQUOTA;
989                         goto set_qf_name;
990                 case Opt_grpjquota:
991                         qtype = GRPQUOTA;
992 set_qf_name:
993                         if (sb_any_quota_enabled(sb)) {
994                                 printk(KERN_ERR
995                                         "EXT4-fs: Cannot change journalled "
996                                         "quota options when quota turned on.\n");
997                                 return 0;
998                         }
999                         qname = match_strdup(&args[0]);
1000                         if (!qname) {
1001                                 printk(KERN_ERR
1002                                         "EXT4-fs: not enough memory for "
1003                                         "storing quotafile name.\n");
1004                                 return 0;
1005                         }
1006                         if (sbi->s_qf_names[qtype] &&
1007                             strcmp(sbi->s_qf_names[qtype], qname)) {
1008                                 printk(KERN_ERR
1009                                         "EXT4-fs: %s quota file already "
1010                                         "specified.\n", QTYPE2NAME(qtype));
1011                                 kfree(qname);
1012                                 return 0;
1013                         }
1014                         sbi->s_qf_names[qtype] = qname;
1015                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1016                                 printk(KERN_ERR
1017                                         "EXT4-fs: quotafile must be on "
1018                                         "filesystem root.\n");
1019                                 kfree(sbi->s_qf_names[qtype]);
1020                                 sbi->s_qf_names[qtype] = NULL;
1021                                 return 0;
1022                         }
1023                         set_opt(sbi->s_mount_opt, QUOTA);
1024                         break;
1025                 case Opt_offusrjquota:
1026                         qtype = USRQUOTA;
1027                         goto clear_qf_name;
1028                 case Opt_offgrpjquota:
1029                         qtype = GRPQUOTA;
1030 clear_qf_name:
1031                         if (sb_any_quota_enabled(sb)) {
1032                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1033                                         "journalled quota options when "
1034                                         "quota turned on.\n");
1035                                 return 0;
1036                         }
1037                         /*
1038                          * The space will be released later when all options
1039                          * are confirmed to be correct
1040                          */
1041                         sbi->s_qf_names[qtype] = NULL;
1042                         break;
1043                 case Opt_jqfmt_vfsold:
1044                         sbi->s_jquota_fmt = QFMT_VFS_OLD;
1045                         break;
1046                 case Opt_jqfmt_vfsv0:
1047                         sbi->s_jquota_fmt = QFMT_VFS_V0;
1048                         break;
1049                 case Opt_quota:
1050                 case Opt_usrquota:
1051                         set_opt(sbi->s_mount_opt, QUOTA);
1052                         set_opt(sbi->s_mount_opt, USRQUOTA);
1053                         break;
1054                 case Opt_grpquota:
1055                         set_opt(sbi->s_mount_opt, QUOTA);
1056                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1057                         break;
1058                 case Opt_noquota:
1059                         if (sb_any_quota_enabled(sb)) {
1060                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1061                                         "options when quota turned on.\n");
1062                                 return 0;
1063                         }
1064                         clear_opt(sbi->s_mount_opt, QUOTA);
1065                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1066                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1067                         break;
1068 #else
1069                 case Opt_quota:
1070                 case Opt_usrquota:
1071                 case Opt_grpquota:
1072                 case Opt_usrjquota:
1073                 case Opt_grpjquota:
1074                 case Opt_offusrjquota:
1075                 case Opt_offgrpjquota:
1076                 case Opt_jqfmt_vfsold:
1077                 case Opt_jqfmt_vfsv0:
1078                         printk(KERN_ERR
1079                                 "EXT4-fs: journalled quota options not "
1080                                 "supported.\n");
1081                         break;
1082                 case Opt_noquota:
1083                         break;
1084 #endif
1085                 case Opt_abort:
1086                         set_opt(sbi->s_mount_opt, ABORT);
1087                         break;
1088                 case Opt_barrier:
1089                         if (match_int(&args[0], &option))
1090                                 return 0;
1091                         if (option)
1092                                 set_opt(sbi->s_mount_opt, BARRIER);
1093                         else
1094                                 clear_opt(sbi->s_mount_opt, BARRIER);
1095                         break;
1096                 case Opt_ignore:
1097                         break;
1098                 case Opt_resize:
1099                         if (!is_remount) {
1100                                 printk("EXT4-fs: resize option only available "
1101                                         "for remount\n");
1102                                 return 0;
1103                         }
1104                         if (match_int(&args[0], &option) != 0)
1105                                 return 0;
1106                         *n_blocks_count = option;
1107                         break;
1108                 case Opt_nobh:
1109                         set_opt(sbi->s_mount_opt, NOBH);
1110                         break;
1111                 case Opt_bh:
1112                         clear_opt(sbi->s_mount_opt, NOBH);
1113                         break;
1114                 case Opt_extents:
1115                         set_opt (sbi->s_mount_opt, EXTENTS);
1116                         break;
1117                 default:
1118                         printk (KERN_ERR
1119                                 "EXT4-fs: Unrecognized mount option \"%s\" "
1120                                 "or missing value\n", p);
1121                         return 0;
1122                 }
1123         }
1124 #ifdef CONFIG_QUOTA
1125         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1126                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1127                      sbi->s_qf_names[USRQUOTA])
1128                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1129
1130                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1131                      sbi->s_qf_names[GRPQUOTA])
1132                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1133
1134                 if ((sbi->s_qf_names[USRQUOTA] &&
1135                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1136                     (sbi->s_qf_names[GRPQUOTA] &&
1137                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1138                         printk(KERN_ERR "EXT4-fs: old and new quota "
1139                                         "format mixing.\n");
1140                         return 0;
1141                 }
1142
1143                 if (!sbi->s_jquota_fmt) {
1144                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1145                                         "not specified.\n");
1146                         return 0;
1147                 }
1148         } else {
1149                 if (sbi->s_jquota_fmt) {
1150                         printk(KERN_ERR "EXT4-fs: journalled quota format "
1151                                         "specified with no journalling "
1152                                         "enabled.\n");
1153                         return 0;
1154                 }
1155         }
1156 #endif
1157         return 1;
1158 }
1159
1160 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1161                             int read_only)
1162 {
1163         struct ext4_sb_info *sbi = EXT4_SB(sb);
1164         int res = 0;
1165
1166         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1167                 printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1168                         "forcing read-only mode\n");
1169                 res = MS_RDONLY;
1170         }
1171         if (read_only)
1172                 return res;
1173         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1174                 printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1175                         "running e2fsck is recommended\n");
1176         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1177                 printk (KERN_WARNING
1178                         "EXT4-fs warning: mounting fs with errors, "
1179                         "running e2fsck is recommended\n");
1180         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1181                  le16_to_cpu(es->s_mnt_count) >=
1182                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1183                 printk (KERN_WARNING
1184                         "EXT4-fs warning: maximal mount count reached, "
1185                         "running e2fsck is recommended\n");
1186         else if (le32_to_cpu(es->s_checkinterval) &&
1187                 (le32_to_cpu(es->s_lastcheck) +
1188                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1189                 printk (KERN_WARNING
1190                         "EXT4-fs warning: checktime reached, "
1191                         "running e2fsck is recommended\n");
1192 #if 0
1193                 /* @@@ We _will_ want to clear the valid bit if we find
1194                  * inconsistencies, to force a fsck at reboot.  But for
1195                  * a plain journaled filesystem we can keep it set as
1196                  * valid forever! :)
1197                  */
1198         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT4_VALID_FS);
1199 #endif
1200         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1201                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1202         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
1203         es->s_mtime = cpu_to_le32(get_seconds());
1204         ext4_update_dynamic_rev(sb);
1205         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1206
1207         ext4_commit_super(sb, es, 1);
1208         if (test_opt(sb, DEBUG))
1209                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1210                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1211                         sb->s_blocksize,
1212                         sbi->s_groups_count,
1213                         EXT4_BLOCKS_PER_GROUP(sb),
1214                         EXT4_INODES_PER_GROUP(sb),
1215                         sbi->s_mount_opt);
1216
1217         printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1218         if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1219                 char b[BDEVNAME_SIZE];
1220
1221                 printk("external journal on %s\n",
1222                         bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1223         } else {
1224                 printk("internal journal\n");
1225         }
1226         return res;
1227 }
1228
1229 /* Called at mount-time, super-block is locked */
1230 static int ext4_check_descriptors (struct super_block * sb)
1231 {
1232         struct ext4_sb_info *sbi = EXT4_SB(sb);
1233         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1234         ext4_fsblk_t last_block;
1235         ext4_fsblk_t block_bitmap;
1236         ext4_fsblk_t inode_bitmap;
1237         ext4_fsblk_t inode_table;
1238         struct ext4_group_desc * gdp = NULL;
1239         int desc_block = 0;
1240         int i;
1241
1242         ext4_debug ("Checking group descriptors");
1243
1244         for (i = 0; i < sbi->s_groups_count; i++)
1245         {
1246                 if (i == sbi->s_groups_count - 1)
1247                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1248                 else
1249                         last_block = first_block +
1250                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1251
1252                 if ((i % EXT4_DESC_PER_BLOCK(sb)) == 0)
1253                         gdp = (struct ext4_group_desc *)
1254                                         sbi->s_group_desc[desc_block++]->b_data;
1255                 block_bitmap = ext4_block_bitmap(sb, gdp);
1256                 if (block_bitmap < first_block || block_bitmap > last_block)
1257                 {
1258                         ext4_error (sb, "ext4_check_descriptors",
1259                                     "Block bitmap for group %d"
1260                                     " not in group (block %llu)!",
1261                                     i, block_bitmap);
1262                         return 0;
1263                 }
1264                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1265                 if (inode_bitmap < first_block || inode_bitmap > last_block)
1266                 {
1267                         ext4_error (sb, "ext4_check_descriptors",
1268                                     "Inode bitmap for group %d"
1269                                     " not in group (block %llu)!",
1270                                     i, inode_bitmap);
1271                         return 0;
1272                 }
1273                 inode_table = ext4_inode_table(sb, gdp);
1274                 if (inode_table < first_block ||
1275                     inode_table + sbi->s_itb_per_group > last_block)
1276                 {
1277                         ext4_error (sb, "ext4_check_descriptors",
1278                                     "Inode table for group %d"
1279                                     " not in group (block %llu)!",
1280                                     i, inode_table);
1281                         return 0;
1282                 }
1283                 first_block += EXT4_BLOCKS_PER_GROUP(sb);
1284                 gdp = (struct ext4_group_desc *)
1285                         ((__u8 *)gdp + EXT4_DESC_SIZE(sb));
1286         }
1287
1288         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1289         sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1290         return 1;
1291 }
1292
1293
1294 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1295  * the superblock) which were deleted from all directories, but held open by
1296  * a process at the time of a crash.  We walk the list and try to delete these
1297  * inodes at recovery time (only with a read-write filesystem).
1298  *
1299  * In order to keep the orphan inode chain consistent during traversal (in
1300  * case of crash during recovery), we link each inode into the superblock
1301  * orphan list_head and handle it the same way as an inode deletion during
1302  * normal operation (which journals the operations for us).
1303  *
1304  * We only do an iget() and an iput() on each inode, which is very safe if we
1305  * accidentally point at an in-use or already deleted inode.  The worst that
1306  * can happen in this case is that we get a "bit already cleared" message from
1307  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1308  * e2fsck was run on this filesystem, and it must have already done the orphan
1309  * inode cleanup for us, so we can safely abort without any further action.
1310  */
1311 static void ext4_orphan_cleanup (struct super_block * sb,
1312                                  struct ext4_super_block * es)
1313 {
1314         unsigned int s_flags = sb->s_flags;
1315         int nr_orphans = 0, nr_truncates = 0;
1316 #ifdef CONFIG_QUOTA
1317         int i;
1318 #endif
1319         if (!es->s_last_orphan) {
1320                 jbd_debug(4, "no orphan inodes to clean up\n");
1321                 return;
1322         }
1323
1324         if (bdev_read_only(sb->s_bdev)) {
1325                 printk(KERN_ERR "EXT4-fs: write access "
1326                         "unavailable, skipping orphan cleanup.\n");
1327                 return;
1328         }
1329
1330         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1331                 if (es->s_last_orphan)
1332                         jbd_debug(1, "Errors on filesystem, "
1333                                   "clearing orphan list.\n");
1334                 es->s_last_orphan = 0;
1335                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1336                 return;
1337         }
1338
1339         if (s_flags & MS_RDONLY) {
1340                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1341                        sb->s_id);
1342                 sb->s_flags &= ~MS_RDONLY;
1343         }
1344 #ifdef CONFIG_QUOTA
1345         /* Needed for iput() to work correctly and not trash data */
1346         sb->s_flags |= MS_ACTIVE;
1347         /* Turn on quotas so that they are updated correctly */
1348         for (i = 0; i < MAXQUOTAS; i++) {
1349                 if (EXT4_SB(sb)->s_qf_names[i]) {
1350                         int ret = ext4_quota_on_mount(sb, i);
1351                         if (ret < 0)
1352                                 printk(KERN_ERR
1353                                         "EXT4-fs: Cannot turn on journalled "
1354                                         "quota: error %d\n", ret);
1355                 }
1356         }
1357 #endif
1358
1359         while (es->s_last_orphan) {
1360                 struct inode *inode;
1361
1362                 if (!(inode =
1363                       ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
1364                         es->s_last_orphan = 0;
1365                         break;
1366                 }
1367
1368                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1369                 DQUOT_INIT(inode);
1370                 if (inode->i_nlink) {
1371                         printk(KERN_DEBUG
1372                                 "%s: truncating inode %lu to %Ld bytes\n",
1373                                 __FUNCTION__, inode->i_ino, inode->i_size);
1374                         jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1375                                   inode->i_ino, inode->i_size);
1376                         ext4_truncate(inode);
1377                         nr_truncates++;
1378                 } else {
1379                         printk(KERN_DEBUG
1380                                 "%s: deleting unreferenced inode %lu\n",
1381                                 __FUNCTION__, inode->i_ino);
1382                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1383                                   inode->i_ino);
1384                         nr_orphans++;
1385                 }
1386                 iput(inode);  /* The delete magic happens here! */
1387         }
1388
1389 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1390
1391         if (nr_orphans)
1392                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1393                        sb->s_id, PLURAL(nr_orphans));
1394         if (nr_truncates)
1395                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1396                        sb->s_id, PLURAL(nr_truncates));
1397 #ifdef CONFIG_QUOTA
1398         /* Turn quotas off */
1399         for (i = 0; i < MAXQUOTAS; i++) {
1400                 if (sb_dqopt(sb)->files[i])
1401                         vfs_quota_off(sb, i);
1402         }
1403 #endif
1404         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1405 }
1406
1407 #define log2(n) ffz(~(n))
1408
1409 /*
1410  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
1411  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
1412  * We need to be 1 filesystem block less than the 2^32 sector limit.
1413  */
1414 static loff_t ext4_max_size(int bits)
1415 {
1416         loff_t res = EXT4_NDIR_BLOCKS;
1417         /* This constant is calculated to be the largest file size for a
1418          * dense, 4k-blocksize file such that the total number of
1419          * sectors in the file, including data and all indirect blocks,
1420          * does not exceed 2^32. */
1421         const loff_t upper_limit = 0x1ff7fffd000LL;
1422
1423         res += 1LL << (bits-2);
1424         res += 1LL << (2*(bits-2));
1425         res += 1LL << (3*(bits-2));
1426         res <<= bits;
1427         if (res > upper_limit)
1428                 res = upper_limit;
1429         return res;
1430 }
1431
1432 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1433                                 ext4_fsblk_t logical_sb_block, int nr)
1434 {
1435         struct ext4_sb_info *sbi = EXT4_SB(sb);
1436         unsigned long bg, first_meta_bg;
1437         int has_super = 0;
1438
1439         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1440
1441         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1442             nr < first_meta_bg)
1443                 return logical_sb_block + nr + 1;
1444         bg = sbi->s_desc_per_block * nr;
1445         if (ext4_bg_has_super(sb, bg))
1446                 has_super = 1;
1447         return (has_super + ext4_group_first_block_no(sb, bg));
1448 }
1449
1450
1451 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1452 {
1453         struct buffer_head * bh;
1454         struct ext4_super_block *es = NULL;
1455         struct ext4_sb_info *sbi;
1456         ext4_fsblk_t block;
1457         ext4_fsblk_t sb_block = get_sb_block(&data);
1458         ext4_fsblk_t logical_sb_block;
1459         unsigned long offset = 0;
1460         unsigned int journal_inum = 0;
1461         unsigned long journal_devnum = 0;
1462         unsigned long def_mount_opts;
1463         struct inode *root;
1464         int blocksize;
1465         int hblock;
1466         int db_count;
1467         int i;
1468         int needs_recovery;
1469         __le32 features;
1470         __u64 blocks_count;
1471
1472         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1473         if (!sbi)
1474                 return -ENOMEM;
1475         sb->s_fs_info = sbi;
1476         sbi->s_mount_opt = 0;
1477         sbi->s_resuid = EXT4_DEF_RESUID;
1478         sbi->s_resgid = EXT4_DEF_RESGID;
1479
1480         unlock_kernel();
1481
1482         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1483         if (!blocksize) {
1484                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1485                 goto out_fail;
1486         }
1487
1488         /*
1489          * The ext4 superblock will not be buffer aligned for other than 1kB
1490          * block sizes.  We need to calculate the offset from buffer start.
1491          */
1492         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1493                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1494                 offset = do_div(logical_sb_block, blocksize);
1495         } else {
1496                 logical_sb_block = sb_block;
1497         }
1498
1499         if (!(bh = sb_bread(sb, logical_sb_block))) {
1500                 printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1501                 goto out_fail;
1502         }
1503         /*
1504          * Note: s_es must be initialized as soon as possible because
1505          *       some ext4 macro-instructions depend on its value
1506          */
1507         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1508         sbi->s_es = es;
1509         sb->s_magic = le16_to_cpu(es->s_magic);
1510         if (sb->s_magic != EXT4_SUPER_MAGIC)
1511                 goto cantfind_ext4;
1512
1513         /* Set defaults before we parse the mount options */
1514         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1515         if (def_mount_opts & EXT4_DEFM_DEBUG)
1516                 set_opt(sbi->s_mount_opt, DEBUG);
1517         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1518                 set_opt(sbi->s_mount_opt, GRPID);
1519         if (def_mount_opts & EXT4_DEFM_UID16)
1520                 set_opt(sbi->s_mount_opt, NO_UID32);
1521 #ifdef CONFIG_EXT4DEV_FS_XATTR
1522         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1523                 set_opt(sbi->s_mount_opt, XATTR_USER);
1524 #endif
1525 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1526         if (def_mount_opts & EXT4_DEFM_ACL)
1527                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1528 #endif
1529         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1530                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1531         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1532                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1533         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1534                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1535
1536         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1537                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1538         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_RO)
1539                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1540         else
1541                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1542
1543         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1544         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1545
1546         set_opt(sbi->s_mount_opt, RESERVATION);
1547
1548         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1549                             NULL, 0))
1550                 goto failed_mount;
1551
1552         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1553                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1554
1555         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1556             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1557              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1558              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1559                 printk(KERN_WARNING
1560                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1561                        "running e2fsck is recommended\n");
1562         /*
1563          * Check feature flags regardless of the revision level, since we
1564          * previously didn't change the revision level when setting the flags,
1565          * so there is a chance incompat flags are set on a rev 0 filesystem.
1566          */
1567         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1568         if (features) {
1569                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1570                        "unsupported optional features (%x).\n",
1571                        sb->s_id, le32_to_cpu(features));
1572                 goto failed_mount;
1573         }
1574         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1575         if (!(sb->s_flags & MS_RDONLY) && features) {
1576                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1577                        "unsupported optional features (%x).\n",
1578                        sb->s_id, le32_to_cpu(features));
1579                 goto failed_mount;
1580         }
1581         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1582
1583         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1584             blocksize > EXT4_MAX_BLOCK_SIZE) {
1585                 printk(KERN_ERR
1586                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1587                        blocksize, sb->s_id);
1588                 goto failed_mount;
1589         }
1590
1591         hblock = bdev_hardsect_size(sb->s_bdev);
1592         if (sb->s_blocksize != blocksize) {
1593                 /*
1594                  * Make sure the blocksize for the filesystem is larger
1595                  * than the hardware sectorsize for the machine.
1596                  */
1597                 if (blocksize < hblock) {
1598                         printk(KERN_ERR "EXT4-fs: blocksize %d too small for "
1599                                "device blocksize %d.\n", blocksize, hblock);
1600                         goto failed_mount;
1601                 }
1602
1603                 brelse (bh);
1604                 sb_set_blocksize(sb, blocksize);
1605                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1606                 offset = do_div(logical_sb_block, blocksize);
1607                 bh = sb_bread(sb, logical_sb_block);
1608                 if (!bh) {
1609                         printk(KERN_ERR
1610                                "EXT4-fs: Can't read superblock on 2nd try.\n");
1611                         goto failed_mount;
1612                 }
1613                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1614                 sbi->s_es = es;
1615                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1616                         printk (KERN_ERR
1617                                 "EXT4-fs: Magic mismatch, very weird !\n");
1618                         goto failed_mount;
1619                 }
1620         }
1621
1622         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
1623
1624         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
1625                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
1626                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
1627         } else {
1628                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1629                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1630                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
1631                     (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
1632                     (sbi->s_inode_size > blocksize)) {
1633                         printk (KERN_ERR
1634                                 "EXT4-fs: unsupported inode size: %d\n",
1635                                 sbi->s_inode_size);
1636                         goto failed_mount;
1637                 }
1638         }
1639         sbi->s_frag_size = EXT4_MIN_FRAG_SIZE <<
1640                                    le32_to_cpu(es->s_log_frag_size);
1641         if (blocksize != sbi->s_frag_size) {
1642                 printk(KERN_ERR
1643                        "EXT4-fs: fragsize %lu != blocksize %u (unsupported)\n",
1644                        sbi->s_frag_size, blocksize);
1645                 goto failed_mount;
1646         }
1647         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
1648         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
1649                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
1650                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
1651                     sbi->s_desc_size & (sbi->s_desc_size - 1)) {
1652                         printk(KERN_ERR
1653                                "EXT4-fs: unsupported descriptor size %lu\n",
1654                                sbi->s_desc_size);
1655                         goto failed_mount;
1656                 }
1657         } else
1658                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
1659         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1660         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1661         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1662         if (EXT4_INODE_SIZE(sb) == 0)
1663                 goto cantfind_ext4;
1664         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
1665         if (sbi->s_inodes_per_block == 0)
1666                 goto cantfind_ext4;
1667         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1668                                         sbi->s_inodes_per_block;
1669         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
1670         sbi->s_sbh = bh;
1671         sbi->s_mount_state = le16_to_cpu(es->s_state);
1672         sbi->s_addr_per_block_bits = log2(EXT4_ADDR_PER_BLOCK(sb));
1673         sbi->s_desc_per_block_bits = log2(EXT4_DESC_PER_BLOCK(sb));
1674         for (i=0; i < 4; i++)
1675                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
1676         sbi->s_def_hash_version = es->s_def_hash_version;
1677
1678         if (sbi->s_blocks_per_group > blocksize * 8) {
1679                 printk (KERN_ERR
1680                         "EXT4-fs: #blocks per group too big: %lu\n",
1681                         sbi->s_blocks_per_group);
1682                 goto failed_mount;
1683         }
1684         if (sbi->s_frags_per_group > blocksize * 8) {
1685                 printk (KERN_ERR
1686                         "EXT4-fs: #fragments per group too big: %lu\n",
1687                         sbi->s_frags_per_group);
1688                 goto failed_mount;
1689         }
1690         if (sbi->s_inodes_per_group > blocksize * 8) {
1691                 printk (KERN_ERR
1692                         "EXT4-fs: #inodes per group too big: %lu\n",
1693                         sbi->s_inodes_per_group);
1694                 goto failed_mount;
1695         }
1696
1697         if (ext4_blocks_count(es) >
1698                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1699                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
1700                         " too large to mount safely\n", sb->s_id);
1701                 if (sizeof(sector_t) < 8)
1702                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
1703                                         "enabled\n");
1704                 goto failed_mount;
1705         }
1706
1707         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
1708                 goto cantfind_ext4;
1709         blocks_count = (ext4_blocks_count(es) -
1710                         le32_to_cpu(es->s_first_data_block) +
1711                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
1712         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
1713         sbi->s_groups_count = blocks_count;
1714         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
1715                    EXT4_DESC_PER_BLOCK(sb);
1716         sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
1717                                     GFP_KERNEL);
1718         if (sbi->s_group_desc == NULL) {
1719                 printk (KERN_ERR "EXT4-fs: not enough memory\n");
1720                 goto failed_mount;
1721         }
1722
1723         bgl_lock_init(&sbi->s_blockgroup_lock);
1724
1725         for (i = 0; i < db_count; i++) {
1726                 block = descriptor_loc(sb, logical_sb_block, i);
1727                 sbi->s_group_desc[i] = sb_bread(sb, block);
1728                 if (!sbi->s_group_desc[i]) {
1729                         printk (KERN_ERR "EXT4-fs: "
1730                                 "can't read group descriptor %d\n", i);
1731                         db_count = i;
1732                         goto failed_mount2;
1733                 }
1734         }
1735         if (!ext4_check_descriptors (sb)) {
1736                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
1737                 goto failed_mount2;
1738         }
1739         sbi->s_gdb_count = db_count;
1740         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1741         spin_lock_init(&sbi->s_next_gen_lock);
1742
1743         percpu_counter_init(&sbi->s_freeblocks_counter,
1744                 ext4_count_free_blocks(sb));
1745         percpu_counter_init(&sbi->s_freeinodes_counter,
1746                 ext4_count_free_inodes(sb));
1747         percpu_counter_init(&sbi->s_dirs_counter,
1748                 ext4_count_dirs(sb));
1749
1750         /* per fileystem reservation list head & lock */
1751         spin_lock_init(&sbi->s_rsv_window_lock);
1752         sbi->s_rsv_window_root = RB_ROOT;
1753         /* Add a single, static dummy reservation to the start of the
1754          * reservation window list --- it gives us a placeholder for
1755          * append-at-start-of-list which makes the allocation logic
1756          * _much_ simpler. */
1757         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1758         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1759         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1760         sbi->s_rsv_window_head.rsv_goal_size = 0;
1761         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
1762
1763         /*
1764          * set up enough so that it can read an inode
1765          */
1766         sb->s_op = &ext4_sops;
1767         sb->s_export_op = &ext4_export_ops;
1768         sb->s_xattr = ext4_xattr_handlers;
1769 #ifdef CONFIG_QUOTA
1770         sb->s_qcop = &ext4_qctl_operations;
1771         sb->dq_op = &ext4_quota_operations;
1772 #endif
1773         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
1774
1775         sb->s_root = NULL;
1776
1777         needs_recovery = (es->s_last_orphan != 0 ||
1778                           EXT4_HAS_INCOMPAT_FEATURE(sb,
1779                                     EXT4_FEATURE_INCOMPAT_RECOVER));
1780
1781         /*
1782          * The first inode we look at is the journal inode.  Don't try
1783          * root first: it may be modified in the journal!
1784          */
1785         if (!test_opt(sb, NOLOAD) &&
1786             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
1787                 if (ext4_load_journal(sb, es, journal_devnum))
1788                         goto failed_mount3;
1789         } else if (journal_inum) {
1790                 if (ext4_create_journal(sb, es, journal_inum))
1791                         goto failed_mount3;
1792         } else {
1793                 if (!silent)
1794                         printk (KERN_ERR
1795                                 "ext4: No journal on filesystem on %s\n",
1796                                 sb->s_id);
1797                 goto failed_mount3;
1798         }
1799
1800         /* We have now updated the journal if required, so we can
1801          * validate the data journaling mode. */
1802         switch (test_opt(sb, DATA_FLAGS)) {
1803         case 0:
1804                 /* No mode set, assume a default based on the journal
1805                  * capabilities: ORDERED_DATA if the journal can
1806                  * cope, else JOURNAL_DATA
1807                  */
1808                 if (jbd2_journal_check_available_features
1809                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
1810                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
1811                 else
1812                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
1813                 break;
1814
1815         case EXT4_MOUNT_ORDERED_DATA:
1816         case EXT4_MOUNT_WRITEBACK_DATA:
1817                 if (!jbd2_journal_check_available_features
1818                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
1819                         printk(KERN_ERR "EXT4-fs: Journal does not support "
1820                                "requested data journaling mode\n");
1821                         goto failed_mount4;
1822                 }
1823         default:
1824                 break;
1825         }
1826
1827         if (test_opt(sb, NOBH)) {
1828                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
1829                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
1830                                 "its supported only with writeback mode\n");
1831                         clear_opt(sbi->s_mount_opt, NOBH);
1832                 }
1833         }
1834         /*
1835          * The jbd2_journal_load will have done any necessary log recovery,
1836          * so we can safely mount the rest of the filesystem now.
1837          */
1838
1839         root = iget(sb, EXT4_ROOT_INO);
1840         sb->s_root = d_alloc_root(root);
1841         if (!sb->s_root) {
1842                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
1843                 iput(root);
1844                 goto failed_mount4;
1845         }
1846         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1847                 dput(sb->s_root);
1848                 sb->s_root = NULL;
1849                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
1850                 goto failed_mount4;
1851         }
1852
1853         ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1854         /*
1855          * akpm: core read_super() calls in here with the superblock locked.
1856          * That deadlocks, because orphan cleanup needs to lock the superblock
1857          * in numerous places.  Here we just pop the lock - it's relatively
1858          * harmless, because we are now ready to accept write_super() requests,
1859          * and aviro says that's the only reason for hanging onto the
1860          * superblock lock.
1861          */
1862         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
1863         ext4_orphan_cleanup(sb, es);
1864         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
1865         if (needs_recovery)
1866                 printk (KERN_INFO "EXT4-fs: recovery complete.\n");
1867         ext4_mark_recovery_complete(sb, es);
1868         printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
1869                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
1870                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
1871                 "writeback");
1872
1873         ext4_ext_init(sb);
1874
1875         lock_kernel();
1876         return 0;
1877
1878 cantfind_ext4:
1879         if (!silent)
1880                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
1881                        sb->s_id);
1882         goto failed_mount;
1883
1884 failed_mount4:
1885         jbd2_journal_destroy(sbi->s_journal);
1886 failed_mount3:
1887         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1888         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1889         percpu_counter_destroy(&sbi->s_dirs_counter);
1890 failed_mount2:
1891         for (i = 0; i < db_count; i++)
1892                 brelse(sbi->s_group_desc[i]);
1893         kfree(sbi->s_group_desc);
1894 failed_mount:
1895 #ifdef CONFIG_QUOTA
1896         for (i = 0; i < MAXQUOTAS; i++)
1897                 kfree(sbi->s_qf_names[i]);
1898 #endif
1899         ext4_blkdev_remove(sbi);
1900         brelse(bh);
1901 out_fail:
1902         sb->s_fs_info = NULL;
1903         kfree(sbi);
1904         lock_kernel();
1905         return -EINVAL;
1906 }
1907
1908 /*
1909  * Setup any per-fs journal parameters now.  We'll do this both on
1910  * initial mount, once the journal has been initialised but before we've
1911  * done any recovery; and again on any subsequent remount.
1912  */
1913 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
1914 {
1915         struct ext4_sb_info *sbi = EXT4_SB(sb);
1916
1917         if (sbi->s_commit_interval)
1918                 journal->j_commit_interval = sbi->s_commit_interval;
1919         /* We could also set up an ext4-specific default for the commit
1920          * interval here, but for now we'll just fall back to the jbd
1921          * default. */
1922
1923         spin_lock(&journal->j_state_lock);
1924         if (test_opt(sb, BARRIER))
1925                 journal->j_flags |= JBD2_BARRIER;
1926         else
1927                 journal->j_flags &= ~JBD2_BARRIER;
1928         spin_unlock(&journal->j_state_lock);
1929 }
1930
1931 static journal_t *ext4_get_journal(struct super_block *sb,
1932                                    unsigned int journal_inum)
1933 {
1934         struct inode *journal_inode;
1935         journal_t *journal;
1936
1937         /* First, test for the existence of a valid inode on disk.  Bad
1938          * things happen if we iget() an unused inode, as the subsequent
1939          * iput() will try to delete it. */
1940
1941         journal_inode = iget(sb, journal_inum);
1942         if (!journal_inode) {
1943                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
1944                 return NULL;
1945         }
1946         if (!journal_inode->i_nlink) {
1947                 make_bad_inode(journal_inode);
1948                 iput(journal_inode);
1949                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
1950                 return NULL;
1951         }
1952
1953         jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
1954                   journal_inode, journal_inode->i_size);
1955         if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
1956                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
1957                 iput(journal_inode);
1958                 return NULL;
1959         }
1960
1961         journal = jbd2_journal_init_inode(journal_inode);
1962         if (!journal) {
1963                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
1964                 iput(journal_inode);
1965                 return NULL;
1966         }
1967         journal->j_private = sb;
1968         ext4_init_journal_params(sb, journal);
1969         return journal;
1970 }
1971
1972 static journal_t *ext4_get_dev_journal(struct super_block *sb,
1973                                        dev_t j_dev)
1974 {
1975         struct buffer_head * bh;
1976         journal_t *journal;
1977         ext4_fsblk_t start;
1978         ext4_fsblk_t len;
1979         int hblock, blocksize;
1980         ext4_fsblk_t sb_block;
1981         unsigned long offset;
1982         struct ext4_super_block * es;
1983         struct block_device *bdev;
1984
1985         bdev = ext4_blkdev_get(j_dev);
1986         if (bdev == NULL)
1987                 return NULL;
1988
1989         if (bd_claim(bdev, sb)) {
1990                 printk(KERN_ERR
1991                         "EXT4: failed to claim external journal device.\n");
1992                 blkdev_put(bdev);
1993                 return NULL;
1994         }
1995
1996         blocksize = sb->s_blocksize;
1997         hblock = bdev_hardsect_size(bdev);
1998         if (blocksize < hblock) {
1999                 printk(KERN_ERR
2000                         "EXT4-fs: blocksize too small for journal device.\n");
2001                 goto out_bdev;
2002         }
2003
2004         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2005         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2006         set_blocksize(bdev, blocksize);
2007         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2008                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2009                        "external journal\n");
2010                 goto out_bdev;
2011         }
2012
2013         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2014         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2015             !(le32_to_cpu(es->s_feature_incompat) &
2016               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2017                 printk(KERN_ERR "EXT4-fs: external journal has "
2018                                         "bad superblock\n");
2019                 brelse(bh);
2020                 goto out_bdev;
2021         }
2022
2023         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2024                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2025                 brelse(bh);
2026                 goto out_bdev;
2027         }
2028
2029         len = ext4_blocks_count(es);
2030         start = sb_block + 1;
2031         brelse(bh);     /* we're done with the superblock */
2032
2033         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2034                                         start, len, blocksize);
2035         if (!journal) {
2036                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2037                 goto out_bdev;
2038         }
2039         journal->j_private = sb;
2040         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2041         wait_on_buffer(journal->j_sb_buffer);
2042         if (!buffer_uptodate(journal->j_sb_buffer)) {
2043                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2044                 goto out_journal;
2045         }
2046         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2047                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2048                                         "user (unsupported) - %d\n",
2049                         be32_to_cpu(journal->j_superblock->s_nr_users));
2050                 goto out_journal;
2051         }
2052         EXT4_SB(sb)->journal_bdev = bdev;
2053         ext4_init_journal_params(sb, journal);
2054         return journal;
2055 out_journal:
2056         jbd2_journal_destroy(journal);
2057 out_bdev:
2058         ext4_blkdev_put(bdev);
2059         return NULL;
2060 }
2061
2062 static int ext4_load_journal(struct super_block *sb,
2063                              struct ext4_super_block *es,
2064                              unsigned long journal_devnum)
2065 {
2066         journal_t *journal;
2067         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2068         dev_t journal_dev;
2069         int err = 0;
2070         int really_read_only;
2071
2072         if (journal_devnum &&
2073             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2074                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2075                         "numbers have changed\n");
2076                 journal_dev = new_decode_dev(journal_devnum);
2077         } else
2078                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2079
2080         really_read_only = bdev_read_only(sb->s_bdev);
2081
2082         /*
2083          * Are we loading a blank journal or performing recovery after a
2084          * crash?  For recovery, we need to check in advance whether we
2085          * can get read-write access to the device.
2086          */
2087
2088         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2089                 if (sb->s_flags & MS_RDONLY) {
2090                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2091                                         "required on readonly filesystem.\n");
2092                         if (really_read_only) {
2093                                 printk(KERN_ERR "EXT4-fs: write access "
2094                                         "unavailable, cannot proceed.\n");
2095                                 return -EROFS;
2096                         }
2097                         printk (KERN_INFO "EXT4-fs: write access will "
2098                                         "be enabled during recovery.\n");
2099                 }
2100         }
2101
2102         if (journal_inum && journal_dev) {
2103                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2104                        "and inode journals!\n");
2105                 return -EINVAL;
2106         }
2107
2108         if (journal_inum) {
2109                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2110                         return -EINVAL;
2111         } else {
2112                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2113                         return -EINVAL;
2114         }
2115
2116         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2117                 err = jbd2_journal_update_format(journal);
2118                 if (err)  {
2119                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2120                         jbd2_journal_destroy(journal);
2121                         return err;
2122                 }
2123         }
2124
2125         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2126                 err = jbd2_journal_wipe(journal, !really_read_only);
2127         if (!err)
2128                 err = jbd2_journal_load(journal);
2129
2130         if (err) {
2131                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2132                 jbd2_journal_destroy(journal);
2133                 return err;
2134         }
2135
2136         EXT4_SB(sb)->s_journal = journal;
2137         ext4_clear_journal_err(sb, es);
2138
2139         if (journal_devnum &&
2140             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2141                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2142                 sb->s_dirt = 1;
2143
2144                 /* Make sure we flush the recovery flag to disk. */
2145                 ext4_commit_super(sb, es, 1);
2146         }
2147
2148         return 0;
2149 }
2150
2151 static int ext4_create_journal(struct super_block * sb,
2152                                struct ext4_super_block * es,
2153                                unsigned int journal_inum)
2154 {
2155         journal_t *journal;
2156
2157         if (sb->s_flags & MS_RDONLY) {
2158                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2159                                 "create journal.\n");
2160                 return -EROFS;
2161         }
2162
2163         if (!(journal = ext4_get_journal(sb, journal_inum)))
2164                 return -EINVAL;
2165
2166         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2167                journal_inum);
2168
2169         if (jbd2_journal_create(journal)) {
2170                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2171                 jbd2_journal_destroy(journal);
2172                 return -EIO;
2173         }
2174
2175         EXT4_SB(sb)->s_journal = journal;
2176
2177         ext4_update_dynamic_rev(sb);
2178         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2179         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2180
2181         es->s_journal_inum = cpu_to_le32(journal_inum);
2182         sb->s_dirt = 1;
2183
2184         /* Make sure we flush the recovery flag to disk. */
2185         ext4_commit_super(sb, es, 1);
2186
2187         return 0;
2188 }
2189
2190 static void ext4_commit_super (struct super_block * sb,
2191                                struct ext4_super_block * es,
2192                                int sync)
2193 {
2194         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2195
2196         if (!sbh)
2197                 return;
2198         es->s_wtime = cpu_to_le32(get_seconds());
2199         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2200         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2201         BUFFER_TRACE(sbh, "marking dirty");
2202         mark_buffer_dirty(sbh);
2203         if (sync)
2204                 sync_dirty_buffer(sbh);
2205 }
2206
2207
2208 /*
2209  * Have we just finished recovery?  If so, and if we are mounting (or
2210  * remounting) the filesystem readonly, then we will end up with a
2211  * consistent fs on disk.  Record that fact.
2212  */
2213 static void ext4_mark_recovery_complete(struct super_block * sb,
2214                                         struct ext4_super_block * es)
2215 {
2216         journal_t *journal = EXT4_SB(sb)->s_journal;
2217
2218         jbd2_journal_lock_updates(journal);
2219         jbd2_journal_flush(journal);
2220         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2221             sb->s_flags & MS_RDONLY) {
2222                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2223                 sb->s_dirt = 0;
2224                 ext4_commit_super(sb, es, 1);
2225         }
2226         jbd2_journal_unlock_updates(journal);
2227 }
2228
2229 /*
2230  * If we are mounting (or read-write remounting) a filesystem whose journal
2231  * has recorded an error from a previous lifetime, move that error to the
2232  * main filesystem now.
2233  */
2234 static void ext4_clear_journal_err(struct super_block * sb,
2235                                    struct ext4_super_block * es)
2236 {
2237         journal_t *journal;
2238         int j_errno;
2239         const char *errstr;
2240
2241         journal = EXT4_SB(sb)->s_journal;
2242
2243         /*
2244          * Now check for any error status which may have been recorded in the
2245          * journal by a prior ext4_error() or ext4_abort()
2246          */
2247
2248         j_errno = jbd2_journal_errno(journal);
2249         if (j_errno) {
2250                 char nbuf[16];
2251
2252                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2253                 ext4_warning(sb, __FUNCTION__, "Filesystem error recorded "
2254                              "from previous mount: %s", errstr);
2255                 ext4_warning(sb, __FUNCTION__, "Marking fs in need of "
2256                              "filesystem check.");
2257
2258                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2259                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2260                 ext4_commit_super (sb, es, 1);
2261
2262                 jbd2_journal_clear_err(journal);
2263         }
2264 }
2265
2266 /*
2267  * Force the running and committing transactions to commit,
2268  * and wait on the commit.
2269  */
2270 int ext4_force_commit(struct super_block *sb)
2271 {
2272         journal_t *journal;
2273         int ret;
2274
2275         if (sb->s_flags & MS_RDONLY)
2276                 return 0;
2277
2278         journal = EXT4_SB(sb)->s_journal;
2279         sb->s_dirt = 0;
2280         ret = ext4_journal_force_commit(journal);
2281         return ret;
2282 }
2283
2284 /*
2285  * Ext4 always journals updates to the superblock itself, so we don't
2286  * have to propagate any other updates to the superblock on disk at this
2287  * point.  Just start an async writeback to get the buffers on their way
2288  * to the disk.
2289  *
2290  * This implicitly triggers the writebehind on sync().
2291  */
2292
2293 static void ext4_write_super (struct super_block * sb)
2294 {
2295         if (mutex_trylock(&sb->s_lock) != 0)
2296                 BUG();
2297         sb->s_dirt = 0;
2298 }
2299
2300 static int ext4_sync_fs(struct super_block *sb, int wait)
2301 {
2302         tid_t target;
2303
2304         sb->s_dirt = 0;
2305         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2306                 if (wait)
2307                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2308         }
2309         return 0;
2310 }
2311
2312 /*
2313  * LVM calls this function before a (read-only) snapshot is created.  This
2314  * gives us a chance to flush the journal completely and mark the fs clean.
2315  */
2316 static void ext4_write_super_lockfs(struct super_block *sb)
2317 {
2318         sb->s_dirt = 0;
2319
2320         if (!(sb->s_flags & MS_RDONLY)) {
2321                 journal_t *journal = EXT4_SB(sb)->s_journal;
2322
2323                 /* Now we set up the journal barrier. */
2324                 jbd2_journal_lock_updates(journal);
2325                 jbd2_journal_flush(journal);
2326
2327                 /* Journal blocked and flushed, clear needs_recovery flag. */
2328                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2329                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2330         }
2331 }
2332
2333 /*
2334  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2335  * flag here, even though the filesystem is not technically dirty yet.
2336  */
2337 static void ext4_unlockfs(struct super_block *sb)
2338 {
2339         if (!(sb->s_flags & MS_RDONLY)) {
2340                 lock_super(sb);
2341                 /* Reser the needs_recovery flag before the fs is unlocked. */
2342                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2343                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2344                 unlock_super(sb);
2345                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2346         }
2347 }
2348
2349 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2350 {
2351         struct ext4_super_block * es;
2352         struct ext4_sb_info *sbi = EXT4_SB(sb);
2353         ext4_fsblk_t n_blocks_count = 0;
2354         unsigned long old_sb_flags;
2355         struct ext4_mount_options old_opts;
2356         int err;
2357 #ifdef CONFIG_QUOTA
2358         int i;
2359 #endif
2360
2361         /* Store the original options */
2362         old_sb_flags = sb->s_flags;
2363         old_opts.s_mount_opt = sbi->s_mount_opt;
2364         old_opts.s_resuid = sbi->s_resuid;
2365         old_opts.s_resgid = sbi->s_resgid;
2366         old_opts.s_commit_interval = sbi->s_commit_interval;
2367 #ifdef CONFIG_QUOTA
2368         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2369         for (i = 0; i < MAXQUOTAS; i++)
2370                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2371 #endif
2372
2373         /*
2374          * Allow the "check" option to be passed as a remount option.
2375          */
2376         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2377                 err = -EINVAL;
2378                 goto restore_opts;
2379         }
2380
2381         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2382                 ext4_abort(sb, __FUNCTION__, "Abort forced by user");
2383
2384         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2385                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2386
2387         es = sbi->s_es;
2388
2389         ext4_init_journal_params(sb, sbi->s_journal);
2390
2391         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2392                 n_blocks_count > ext4_blocks_count(es)) {
2393                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2394                         err = -EROFS;
2395                         goto restore_opts;
2396                 }
2397
2398                 if (*flags & MS_RDONLY) {
2399                         /*
2400                          * First of all, the unconditional stuff we have to do
2401                          * to disable replay of the journal when we next remount
2402                          */
2403                         sb->s_flags |= MS_RDONLY;
2404
2405                         /*
2406                          * OK, test if we are remounting a valid rw partition
2407                          * readonly, and if so set the rdonly flag and then
2408                          * mark the partition as valid again.
2409                          */
2410                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2411                             (sbi->s_mount_state & EXT4_VALID_FS))
2412                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
2413
2414                         ext4_mark_recovery_complete(sb, es);
2415                 } else {
2416                         __le32 ret;
2417                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2418                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2419                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2420                                        "remount RDWR because of unsupported "
2421                                        "optional features (%x).\n",
2422                                        sb->s_id, le32_to_cpu(ret));
2423                                 err = -EROFS;
2424                                 goto restore_opts;
2425                         }
2426
2427                         /*
2428                          * If we have an unprocessed orphan list hanging
2429                          * around from a previously readonly bdev mount,
2430                          * require a full umount/remount for now.
2431                          */
2432                         if (es->s_last_orphan) {
2433                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2434                                        "remount RDWR because of unprocessed "
2435                                        "orphan inode list.  Please "
2436                                        "umount/remount instead.\n",
2437                                        sb->s_id);
2438                                 err = -EINVAL;
2439                                 goto restore_opts;
2440                         }
2441
2442                         /*
2443                          * Mounting a RDONLY partition read-write, so reread
2444                          * and store the current valid flag.  (It may have
2445                          * been changed by e2fsck since we originally mounted
2446                          * the partition.)
2447                          */
2448                         ext4_clear_journal_err(sb, es);
2449                         sbi->s_mount_state = le16_to_cpu(es->s_state);
2450                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2451                                 goto restore_opts;
2452                         if (!ext4_setup_super (sb, es, 0))
2453                                 sb->s_flags &= ~MS_RDONLY;
2454                 }
2455         }
2456 #ifdef CONFIG_QUOTA
2457         /* Release old quota file names */
2458         for (i = 0; i < MAXQUOTAS; i++)
2459                 if (old_opts.s_qf_names[i] &&
2460                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2461                         kfree(old_opts.s_qf_names[i]);
2462 #endif
2463         return 0;
2464 restore_opts:
2465         sb->s_flags = old_sb_flags;
2466         sbi->s_mount_opt = old_opts.s_mount_opt;
2467         sbi->s_resuid = old_opts.s_resuid;
2468         sbi->s_resgid = old_opts.s_resgid;
2469         sbi->s_commit_interval = old_opts.s_commit_interval;
2470 #ifdef CONFIG_QUOTA
2471         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2472         for (i = 0; i < MAXQUOTAS; i++) {
2473                 if (sbi->s_qf_names[i] &&
2474                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2475                         kfree(sbi->s_qf_names[i]);
2476                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2477         }
2478 #endif
2479         return err;
2480 }
2481
2482 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2483 {
2484         struct super_block *sb = dentry->d_sb;
2485         struct ext4_sb_info *sbi = EXT4_SB(sb);
2486         struct ext4_super_block *es = sbi->s_es;
2487         ext4_fsblk_t overhead;
2488         int i;
2489         u64 fsid;
2490
2491         if (test_opt (sb, MINIX_DF))
2492                 overhead = 0;
2493         else {
2494                 unsigned long ngroups;
2495                 ngroups = EXT4_SB(sb)->s_groups_count;
2496                 smp_rmb();
2497
2498                 /*
2499                  * Compute the overhead (FS structures)
2500                  */
2501
2502                 /*
2503                  * All of the blocks before first_data_block are
2504                  * overhead
2505                  */
2506                 overhead = le32_to_cpu(es->s_first_data_block);
2507
2508                 /*
2509                  * Add the overhead attributed to the superblock and
2510                  * block group descriptors.  If the sparse superblocks
2511                  * feature is turned on, then not all groups have this.
2512                  */
2513                 for (i = 0; i < ngroups; i++) {
2514                         overhead += ext4_bg_has_super(sb, i) +
2515                                 ext4_bg_num_gdb(sb, i);
2516                         cond_resched();
2517                 }
2518
2519                 /*
2520                  * Every block group has an inode bitmap, a block
2521                  * bitmap, and an inode table.
2522                  */
2523                 overhead += (ngroups * (2 + EXT4_SB(sb)->s_itb_per_group));
2524         }
2525
2526         buf->f_type = EXT4_SUPER_MAGIC;
2527         buf->f_bsize = sb->s_blocksize;
2528         buf->f_blocks = ext4_blocks_count(es) - overhead;
2529         buf->f_bfree = percpu_counter_sum(&sbi->s_freeblocks_counter);
2530         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2531         if (buf->f_bfree < ext4_r_blocks_count(es))
2532                 buf->f_bavail = 0;
2533         buf->f_files = le32_to_cpu(es->s_inodes_count);
2534         buf->f_ffree = percpu_counter_sum(&sbi->s_freeinodes_counter);
2535         buf->f_namelen = EXT4_NAME_LEN;
2536         fsid = le64_to_cpup((void *)es->s_uuid) ^
2537                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2538         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2539         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2540         return 0;
2541 }
2542
2543 /* Helper function for writing quotas on sync - we need to start transaction before quota file
2544  * is locked for write. Otherwise the are possible deadlocks:
2545  * Process 1                         Process 2
2546  * ext4_create()                     quota_sync()
2547  *   jbd2_journal_start()                   write_dquot()
2548  *   DQUOT_INIT()                        down(dqio_mutex)
2549  *     down(dqio_mutex)                    jbd2_journal_start()
2550  *
2551  */
2552
2553 #ifdef CONFIG_QUOTA
2554
2555 static inline struct inode *dquot_to_inode(struct dquot *dquot)
2556 {
2557         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
2558 }
2559
2560 static int ext4_dquot_initialize(struct inode *inode, int type)
2561 {
2562         handle_t *handle;
2563         int ret, err;
2564
2565         /* We may create quota structure so we need to reserve enough blocks */
2566         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
2567         if (IS_ERR(handle))
2568                 return PTR_ERR(handle);
2569         ret = dquot_initialize(inode, type);
2570         err = ext4_journal_stop(handle);
2571         if (!ret)
2572                 ret = err;
2573         return ret;
2574 }
2575
2576 static int ext4_dquot_drop(struct inode *inode)
2577 {
2578         handle_t *handle;
2579         int ret, err;
2580
2581         /* We may delete quota structure so we need to reserve enough blocks */
2582         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
2583         if (IS_ERR(handle))
2584                 return PTR_ERR(handle);
2585         ret = dquot_drop(inode);
2586         err = ext4_journal_stop(handle);
2587         if (!ret)
2588                 ret = err;
2589         return ret;
2590 }
2591
2592 static int ext4_write_dquot(struct dquot *dquot)
2593 {
2594         int ret, err;
2595         handle_t *handle;
2596         struct inode *inode;
2597
2598         inode = dquot_to_inode(dquot);
2599         handle = ext4_journal_start(inode,
2600                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
2601         if (IS_ERR(handle))
2602                 return PTR_ERR(handle);
2603         ret = dquot_commit(dquot);
2604         err = ext4_journal_stop(handle);
2605         if (!ret)
2606                 ret = err;
2607         return ret;
2608 }
2609
2610 static int ext4_acquire_dquot(struct dquot *dquot)
2611 {
2612         int ret, err;
2613         handle_t *handle;
2614
2615         handle = ext4_journal_start(dquot_to_inode(dquot),
2616                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
2617         if (IS_ERR(handle))
2618                 return PTR_ERR(handle);
2619         ret = dquot_acquire(dquot);
2620         err = ext4_journal_stop(handle);
2621         if (!ret)
2622                 ret = err;
2623         return ret;
2624 }
2625
2626 static int ext4_release_dquot(struct dquot *dquot)
2627 {
2628         int ret, err;
2629         handle_t *handle;
2630
2631         handle = ext4_journal_start(dquot_to_inode(dquot),
2632                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
2633         if (IS_ERR(handle))
2634                 return PTR_ERR(handle);
2635         ret = dquot_release(dquot);
2636         err = ext4_journal_stop(handle);
2637         if (!ret)
2638                 ret = err;
2639         return ret;
2640 }
2641
2642 static int ext4_mark_dquot_dirty(struct dquot *dquot)
2643 {
2644         /* Are we journalling quotas? */
2645         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
2646             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
2647                 dquot_mark_dquot_dirty(dquot);
2648                 return ext4_write_dquot(dquot);
2649         } else {
2650                 return dquot_mark_dquot_dirty(dquot);
2651         }
2652 }
2653
2654 static int ext4_write_info(struct super_block *sb, int type)
2655 {
2656         int ret, err;
2657         handle_t *handle;
2658
2659         /* Data block + inode block */
2660         handle = ext4_journal_start(sb->s_root->d_inode, 2);
2661         if (IS_ERR(handle))
2662                 return PTR_ERR(handle);
2663         ret = dquot_commit_info(sb, type);
2664         err = ext4_journal_stop(handle);
2665         if (!ret)
2666                 ret = err;
2667         return ret;
2668 }
2669
2670 /*
2671  * Turn on quotas during mount time - we need to find
2672  * the quota file and such...
2673  */
2674 static int ext4_quota_on_mount(struct super_block *sb, int type)
2675 {
2676         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
2677                         EXT4_SB(sb)->s_jquota_fmt, type);
2678 }
2679
2680 /*
2681  * Standard function to be called on quota_on
2682  */
2683 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
2684                          char *path)
2685 {
2686         int err;
2687         struct nameidata nd;
2688
2689         if (!test_opt(sb, QUOTA))
2690                 return -EINVAL;
2691         /* Not journalling quota? */
2692         if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
2693             !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
2694                 return vfs_quota_on(sb, type, format_id, path);
2695         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
2696         if (err)
2697                 return err;
2698         /* Quotafile not on the same filesystem? */
2699         if (nd.mnt->mnt_sb != sb) {
2700                 path_release(&nd);
2701                 return -EXDEV;
2702         }
2703         /* Quotafile not of fs root? */
2704         if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
2705                 printk(KERN_WARNING
2706                         "EXT4-fs: Quota file not on filesystem root. "
2707                         "Journalled quota will not work.\n");
2708         path_release(&nd);
2709         return vfs_quota_on(sb, type, format_id, path);
2710 }
2711
2712 /* Read data from quotafile - avoid pagecache and such because we cannot afford
2713  * acquiring the locks... As quota files are never truncated and quota code
2714  * itself serializes the operations (and noone else should touch the files)
2715  * we don't have to be afraid of races */
2716 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
2717                                size_t len, loff_t off)
2718 {
2719         struct inode *inode = sb_dqopt(sb)->files[type];
2720         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2721         int err = 0;
2722         int offset = off & (sb->s_blocksize - 1);
2723         int tocopy;
2724         size_t toread;
2725         struct buffer_head *bh;
2726         loff_t i_size = i_size_read(inode);
2727
2728         if (off > i_size)
2729                 return 0;
2730         if (off+len > i_size)
2731                 len = i_size-off;
2732         toread = len;
2733         while (toread > 0) {
2734                 tocopy = sb->s_blocksize - offset < toread ?
2735                                 sb->s_blocksize - offset : toread;
2736                 bh = ext4_bread(NULL, inode, blk, 0, &err);
2737                 if (err)
2738                         return err;
2739                 if (!bh)        /* A hole? */
2740                         memset(data, 0, tocopy);
2741                 else
2742                         memcpy(data, bh->b_data+offset, tocopy);
2743                 brelse(bh);
2744                 offset = 0;
2745                 toread -= tocopy;
2746                 data += tocopy;
2747                 blk++;
2748         }
2749         return len;
2750 }
2751
2752 /* Write to quotafile (we know the transaction is already started and has
2753  * enough credits) */
2754 static ssize_t ext4_quota_write(struct super_block *sb, int type,
2755                                 const char *data, size_t len, loff_t off)
2756 {
2757         struct inode *inode = sb_dqopt(sb)->files[type];
2758         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2759         int err = 0;
2760         int offset = off & (sb->s_blocksize - 1);
2761         int tocopy;
2762         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
2763         size_t towrite = len;
2764         struct buffer_head *bh;
2765         handle_t *handle = journal_current_handle();
2766
2767         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2768         while (towrite > 0) {
2769                 tocopy = sb->s_blocksize - offset < towrite ?
2770                                 sb->s_blocksize - offset : towrite;
2771                 bh = ext4_bread(handle, inode, blk, 1, &err);
2772                 if (!bh)
2773                         goto out;
2774                 if (journal_quota) {
2775                         err = ext4_journal_get_write_access(handle, bh);
2776                         if (err) {
2777                                 brelse(bh);
2778                                 goto out;
2779                         }
2780                 }
2781                 lock_buffer(bh);
2782                 memcpy(bh->b_data+offset, data, tocopy);
2783                 flush_dcache_page(bh->b_page);
2784                 unlock_buffer(bh);
2785                 if (journal_quota)
2786                         err = ext4_journal_dirty_metadata(handle, bh);
2787                 else {
2788                         /* Always do at least ordered writes for quotas */
2789                         err = ext4_journal_dirty_data(handle, bh);
2790                         mark_buffer_dirty(bh);
2791                 }
2792                 brelse(bh);
2793                 if (err)
2794                         goto out;
2795                 offset = 0;
2796                 towrite -= tocopy;
2797                 data += tocopy;
2798                 blk++;
2799         }
2800 out:
2801         if (len == towrite)
2802                 return err;
2803         if (inode->i_size < off+len-towrite) {
2804                 i_size_write(inode, off+len-towrite);
2805                 EXT4_I(inode)->i_disksize = inode->i_size;
2806         }
2807         inode->i_version++;
2808         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2809         ext4_mark_inode_dirty(handle, inode);
2810         mutex_unlock(&inode->i_mutex);
2811         return len - towrite;
2812 }
2813
2814 #endif
2815
2816 static int ext4_get_sb(struct file_system_type *fs_type,
2817         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
2818 {
2819         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
2820 }
2821
2822 static struct file_system_type ext4dev_fs_type = {
2823         .owner          = THIS_MODULE,
2824         .name           = "ext4dev",
2825         .get_sb         = ext4_get_sb,
2826         .kill_sb        = kill_block_super,
2827         .fs_flags       = FS_REQUIRES_DEV,
2828 };
2829
2830 static int __init init_ext4_fs(void)
2831 {
2832         int err = init_ext4_xattr();
2833         if (err)
2834                 return err;
2835         err = init_inodecache();
2836         if (err)
2837                 goto out1;
2838         err = register_filesystem(&ext4dev_fs_type);
2839         if (err)
2840                 goto out;
2841         return 0;
2842 out:
2843         destroy_inodecache();
2844 out1:
2845         exit_ext4_xattr();
2846         return err;
2847 }
2848
2849 static void __exit exit_ext4_fs(void)
2850 {
2851         unregister_filesystem(&ext4dev_fs_type);
2852         destroy_inodecache();
2853         exit_ext4_xattr();
2854 }
2855
2856 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
2857 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
2858 MODULE_LICENSE("GPL");
2859 module_init(init_ext4_fs)
2860 module_exit(exit_ext4_fs)