463b52b32a0ed21151e75a5b06e3fb5d6611be6e
[linux-drm-fsl-dcu.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 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         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1522                 set_opt(sbi->s_mount_opt, XATTR_USER);
1523         if (def_mount_opts & EXT4_DEFM_ACL)
1524                 set_opt(sbi->s_mount_opt, POSIX_ACL);
1525         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1526                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1527         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1528                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1529         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1530                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1531
1532         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1533                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1534         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_RO)
1535                 set_opt(sbi->s_mount_opt, ERRORS_RO);
1536         else
1537                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
1538
1539         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1540         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1541
1542         set_opt(sbi->s_mount_opt, RESERVATION);
1543
1544         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1545                             NULL, 0))
1546                 goto failed_mount;
1547
1548         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1549                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1550
1551         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1552             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1553              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1554              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1555                 printk(KERN_WARNING
1556                        "EXT4-fs warning: feature flags set on rev 0 fs, "
1557                        "running e2fsck is recommended\n");
1558         /*
1559          * Check feature flags regardless of the revision level, since we
1560          * previously didn't change the revision level when setting the flags,
1561          * so there is a chance incompat flags are set on a rev 0 filesystem.
1562          */
1563         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1564         if (features) {
1565                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1566                        "unsupported optional features (%x).\n",
1567                        sb->s_id, le32_to_cpu(features));
1568                 goto failed_mount;
1569         }
1570         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1571         if (!(sb->s_flags & MS_RDONLY) && features) {
1572                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1573                        "unsupported optional features (%x).\n",
1574                        sb->s_id, le32_to_cpu(features));
1575                 goto failed_mount;
1576         }
1577         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1578
1579         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1580             blocksize > EXT4_MAX_BLOCK_SIZE) {
1581                 printk(KERN_ERR
1582                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1583                        blocksize, sb->s_id);
1584                 goto failed_mount;
1585         }
1586
1587         hblock = bdev_hardsect_size(sb->s_bdev);
1588         if (sb->s_blocksize != blocksize) {
1589                 /*
1590                  * Make sure the blocksize for the filesystem is larger
1591                  * than the hardware sectorsize for the machine.
1592                  */
1593                 if (blocksize < hblock) {
1594                         printk(KERN_ERR "EXT4-fs: blocksize %d too small for "
1595                                "device blocksize %d.\n", blocksize, hblock);
1596                         goto failed_mount;
1597                 }
1598
1599                 brelse (bh);
1600                 sb_set_blocksize(sb, blocksize);
1601                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1602                 offset = do_div(logical_sb_block, blocksize);
1603                 bh = sb_bread(sb, logical_sb_block);
1604                 if (!bh) {
1605                         printk(KERN_ERR
1606                                "EXT4-fs: Can't read superblock on 2nd try.\n");
1607                         goto failed_mount;
1608                 }
1609                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1610                 sbi->s_es = es;
1611                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1612                         printk (KERN_ERR
1613                                 "EXT4-fs: Magic mismatch, very weird !\n");
1614                         goto failed_mount;
1615                 }
1616         }
1617
1618         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
1619
1620         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
1621                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
1622                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
1623         } else {
1624                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1625                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1626                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
1627                     (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
1628                     (sbi->s_inode_size > blocksize)) {
1629                         printk (KERN_ERR
1630                                 "EXT4-fs: unsupported inode size: %d\n",
1631                                 sbi->s_inode_size);
1632                         goto failed_mount;
1633                 }
1634         }
1635         sbi->s_frag_size = EXT4_MIN_FRAG_SIZE <<
1636                                    le32_to_cpu(es->s_log_frag_size);
1637         if (blocksize != sbi->s_frag_size) {
1638                 printk(KERN_ERR
1639                        "EXT4-fs: fragsize %lu != blocksize %u (unsupported)\n",
1640                        sbi->s_frag_size, blocksize);
1641                 goto failed_mount;
1642         }
1643         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
1644         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
1645                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
1646                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
1647                     sbi->s_desc_size & (sbi->s_desc_size - 1)) {
1648                         printk(KERN_ERR
1649                                "EXT4-fs: unsupported descriptor size %lu\n",
1650                                sbi->s_desc_size);
1651                         goto failed_mount;
1652                 }
1653         } else
1654                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
1655         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1656         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1657         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1658         if (EXT4_INODE_SIZE(sb) == 0)
1659                 goto cantfind_ext4;
1660         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
1661         if (sbi->s_inodes_per_block == 0)
1662                 goto cantfind_ext4;
1663         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1664                                         sbi->s_inodes_per_block;
1665         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
1666         sbi->s_sbh = bh;
1667         sbi->s_mount_state = le16_to_cpu(es->s_state);
1668         sbi->s_addr_per_block_bits = log2(EXT4_ADDR_PER_BLOCK(sb));
1669         sbi->s_desc_per_block_bits = log2(EXT4_DESC_PER_BLOCK(sb));
1670         for (i=0; i < 4; i++)
1671                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
1672         sbi->s_def_hash_version = es->s_def_hash_version;
1673
1674         if (sbi->s_blocks_per_group > blocksize * 8) {
1675                 printk (KERN_ERR
1676                         "EXT4-fs: #blocks per group too big: %lu\n",
1677                         sbi->s_blocks_per_group);
1678                 goto failed_mount;
1679         }
1680         if (sbi->s_frags_per_group > blocksize * 8) {
1681                 printk (KERN_ERR
1682                         "EXT4-fs: #fragments per group too big: %lu\n",
1683                         sbi->s_frags_per_group);
1684                 goto failed_mount;
1685         }
1686         if (sbi->s_inodes_per_group > blocksize * 8) {
1687                 printk (KERN_ERR
1688                         "EXT4-fs: #inodes per group too big: %lu\n",
1689                         sbi->s_inodes_per_group);
1690                 goto failed_mount;
1691         }
1692
1693         if (ext4_blocks_count(es) >
1694                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1695                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
1696                         " too large to mount safely\n", sb->s_id);
1697                 if (sizeof(sector_t) < 8)
1698                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
1699                                         "enabled\n");
1700                 goto failed_mount;
1701         }
1702
1703         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
1704                 goto cantfind_ext4;
1705         blocks_count = (ext4_blocks_count(es) -
1706                         le32_to_cpu(es->s_first_data_block) +
1707                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
1708         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
1709         sbi->s_groups_count = blocks_count;
1710         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
1711                    EXT4_DESC_PER_BLOCK(sb);
1712         sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
1713                                     GFP_KERNEL);
1714         if (sbi->s_group_desc == NULL) {
1715                 printk (KERN_ERR "EXT4-fs: not enough memory\n");
1716                 goto failed_mount;
1717         }
1718
1719         bgl_lock_init(&sbi->s_blockgroup_lock);
1720
1721         for (i = 0; i < db_count; i++) {
1722                 block = descriptor_loc(sb, logical_sb_block, i);
1723                 sbi->s_group_desc[i] = sb_bread(sb, block);
1724                 if (!sbi->s_group_desc[i]) {
1725                         printk (KERN_ERR "EXT4-fs: "
1726                                 "can't read group descriptor %d\n", i);
1727                         db_count = i;
1728                         goto failed_mount2;
1729                 }
1730         }
1731         if (!ext4_check_descriptors (sb)) {
1732                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
1733                 goto failed_mount2;
1734         }
1735         sbi->s_gdb_count = db_count;
1736         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1737         spin_lock_init(&sbi->s_next_gen_lock);
1738
1739         percpu_counter_init(&sbi->s_freeblocks_counter,
1740                 ext4_count_free_blocks(sb));
1741         percpu_counter_init(&sbi->s_freeinodes_counter,
1742                 ext4_count_free_inodes(sb));
1743         percpu_counter_init(&sbi->s_dirs_counter,
1744                 ext4_count_dirs(sb));
1745
1746         /* per fileystem reservation list head & lock */
1747         spin_lock_init(&sbi->s_rsv_window_lock);
1748         sbi->s_rsv_window_root = RB_ROOT;
1749         /* Add a single, static dummy reservation to the start of the
1750          * reservation window list --- it gives us a placeholder for
1751          * append-at-start-of-list which makes the allocation logic
1752          * _much_ simpler. */
1753         sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1754         sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1755         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1756         sbi->s_rsv_window_head.rsv_goal_size = 0;
1757         ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
1758
1759         /*
1760          * set up enough so that it can read an inode
1761          */
1762         sb->s_op = &ext4_sops;
1763         sb->s_export_op = &ext4_export_ops;
1764         sb->s_xattr = ext4_xattr_handlers;
1765 #ifdef CONFIG_QUOTA
1766         sb->s_qcop = &ext4_qctl_operations;
1767         sb->dq_op = &ext4_quota_operations;
1768 #endif
1769         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
1770
1771         sb->s_root = NULL;
1772
1773         needs_recovery = (es->s_last_orphan != 0 ||
1774                           EXT4_HAS_INCOMPAT_FEATURE(sb,
1775                                     EXT4_FEATURE_INCOMPAT_RECOVER));
1776
1777         /*
1778          * The first inode we look at is the journal inode.  Don't try
1779          * root first: it may be modified in the journal!
1780          */
1781         if (!test_opt(sb, NOLOAD) &&
1782             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
1783                 if (ext4_load_journal(sb, es, journal_devnum))
1784                         goto failed_mount3;
1785         } else if (journal_inum) {
1786                 if (ext4_create_journal(sb, es, journal_inum))
1787                         goto failed_mount3;
1788         } else {
1789                 if (!silent)
1790                         printk (KERN_ERR
1791                                 "ext4: No journal on filesystem on %s\n",
1792                                 sb->s_id);
1793                 goto failed_mount3;
1794         }
1795
1796         /* We have now updated the journal if required, so we can
1797          * validate the data journaling mode. */
1798         switch (test_opt(sb, DATA_FLAGS)) {
1799         case 0:
1800                 /* No mode set, assume a default based on the journal
1801                  * capabilities: ORDERED_DATA if the journal can
1802                  * cope, else JOURNAL_DATA
1803                  */
1804                 if (jbd2_journal_check_available_features
1805                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
1806                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
1807                 else
1808                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
1809                 break;
1810
1811         case EXT4_MOUNT_ORDERED_DATA:
1812         case EXT4_MOUNT_WRITEBACK_DATA:
1813                 if (!jbd2_journal_check_available_features
1814                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
1815                         printk(KERN_ERR "EXT4-fs: Journal does not support "
1816                                "requested data journaling mode\n");
1817                         goto failed_mount4;
1818                 }
1819         default:
1820                 break;
1821         }
1822
1823         if (test_opt(sb, NOBH)) {
1824                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
1825                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
1826                                 "its supported only with writeback mode\n");
1827                         clear_opt(sbi->s_mount_opt, NOBH);
1828                 }
1829         }
1830         /*
1831          * The jbd2_journal_load will have done any necessary log recovery,
1832          * so we can safely mount the rest of the filesystem now.
1833          */
1834
1835         root = iget(sb, EXT4_ROOT_INO);
1836         sb->s_root = d_alloc_root(root);
1837         if (!sb->s_root) {
1838                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
1839                 iput(root);
1840                 goto failed_mount4;
1841         }
1842         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1843                 dput(sb->s_root);
1844                 sb->s_root = NULL;
1845                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
1846                 goto failed_mount4;
1847         }
1848
1849         ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1850         /*
1851          * akpm: core read_super() calls in here with the superblock locked.
1852          * That deadlocks, because orphan cleanup needs to lock the superblock
1853          * in numerous places.  Here we just pop the lock - it's relatively
1854          * harmless, because we are now ready to accept write_super() requests,
1855          * and aviro says that's the only reason for hanging onto the
1856          * superblock lock.
1857          */
1858         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
1859         ext4_orphan_cleanup(sb, es);
1860         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
1861         if (needs_recovery)
1862                 printk (KERN_INFO "EXT4-fs: recovery complete.\n");
1863         ext4_mark_recovery_complete(sb, es);
1864         printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
1865                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
1866                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
1867                 "writeback");
1868
1869         ext4_ext_init(sb);
1870
1871         lock_kernel();
1872         return 0;
1873
1874 cantfind_ext4:
1875         if (!silent)
1876                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
1877                        sb->s_id);
1878         goto failed_mount;
1879
1880 failed_mount4:
1881         jbd2_journal_destroy(sbi->s_journal);
1882 failed_mount3:
1883         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1884         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1885         percpu_counter_destroy(&sbi->s_dirs_counter);
1886 failed_mount2:
1887         for (i = 0; i < db_count; i++)
1888                 brelse(sbi->s_group_desc[i]);
1889         kfree(sbi->s_group_desc);
1890 failed_mount:
1891 #ifdef CONFIG_QUOTA
1892         for (i = 0; i < MAXQUOTAS; i++)
1893                 kfree(sbi->s_qf_names[i]);
1894 #endif
1895         ext4_blkdev_remove(sbi);
1896         brelse(bh);
1897 out_fail:
1898         sb->s_fs_info = NULL;
1899         kfree(sbi);
1900         lock_kernel();
1901         return -EINVAL;
1902 }
1903
1904 /*
1905  * Setup any per-fs journal parameters now.  We'll do this both on
1906  * initial mount, once the journal has been initialised but before we've
1907  * done any recovery; and again on any subsequent remount.
1908  */
1909 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
1910 {
1911         struct ext4_sb_info *sbi = EXT4_SB(sb);
1912
1913         if (sbi->s_commit_interval)
1914                 journal->j_commit_interval = sbi->s_commit_interval;
1915         /* We could also set up an ext4-specific default for the commit
1916          * interval here, but for now we'll just fall back to the jbd
1917          * default. */
1918
1919         spin_lock(&journal->j_state_lock);
1920         if (test_opt(sb, BARRIER))
1921                 journal->j_flags |= JBD2_BARRIER;
1922         else
1923                 journal->j_flags &= ~JBD2_BARRIER;
1924         spin_unlock(&journal->j_state_lock);
1925 }
1926
1927 static journal_t *ext4_get_journal(struct super_block *sb,
1928                                    unsigned int journal_inum)
1929 {
1930         struct inode *journal_inode;
1931         journal_t *journal;
1932
1933         /* First, test for the existence of a valid inode on disk.  Bad
1934          * things happen if we iget() an unused inode, as the subsequent
1935          * iput() will try to delete it. */
1936
1937         journal_inode = iget(sb, journal_inum);
1938         if (!journal_inode) {
1939                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
1940                 return NULL;
1941         }
1942         if (!journal_inode->i_nlink) {
1943                 make_bad_inode(journal_inode);
1944                 iput(journal_inode);
1945                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
1946                 return NULL;
1947         }
1948
1949         jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
1950                   journal_inode, journal_inode->i_size);
1951         if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
1952                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
1953                 iput(journal_inode);
1954                 return NULL;
1955         }
1956
1957         journal = jbd2_journal_init_inode(journal_inode);
1958         if (!journal) {
1959                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
1960                 iput(journal_inode);
1961                 return NULL;
1962         }
1963         journal->j_private = sb;
1964         ext4_init_journal_params(sb, journal);
1965         return journal;
1966 }
1967
1968 static journal_t *ext4_get_dev_journal(struct super_block *sb,
1969                                        dev_t j_dev)
1970 {
1971         struct buffer_head * bh;
1972         journal_t *journal;
1973         ext4_fsblk_t start;
1974         ext4_fsblk_t len;
1975         int hblock, blocksize;
1976         ext4_fsblk_t sb_block;
1977         unsigned long offset;
1978         struct ext4_super_block * es;
1979         struct block_device *bdev;
1980
1981         bdev = ext4_blkdev_get(j_dev);
1982         if (bdev == NULL)
1983                 return NULL;
1984
1985         if (bd_claim(bdev, sb)) {
1986                 printk(KERN_ERR
1987                         "EXT4: failed to claim external journal device.\n");
1988                 blkdev_put(bdev);
1989                 return NULL;
1990         }
1991
1992         blocksize = sb->s_blocksize;
1993         hblock = bdev_hardsect_size(bdev);
1994         if (blocksize < hblock) {
1995                 printk(KERN_ERR
1996                         "EXT4-fs: blocksize too small for journal device.\n");
1997                 goto out_bdev;
1998         }
1999
2000         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2001         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2002         set_blocksize(bdev, blocksize);
2003         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2004                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2005                        "external journal\n");
2006                 goto out_bdev;
2007         }
2008
2009         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2010         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2011             !(le32_to_cpu(es->s_feature_incompat) &
2012               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2013                 printk(KERN_ERR "EXT4-fs: external journal has "
2014                                         "bad superblock\n");
2015                 brelse(bh);
2016                 goto out_bdev;
2017         }
2018
2019         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2020                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2021                 brelse(bh);
2022                 goto out_bdev;
2023         }
2024
2025         len = ext4_blocks_count(es);
2026         start = sb_block + 1;
2027         brelse(bh);     /* we're done with the superblock */
2028
2029         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2030                                         start, len, blocksize);
2031         if (!journal) {
2032                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2033                 goto out_bdev;
2034         }
2035         journal->j_private = sb;
2036         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2037         wait_on_buffer(journal->j_sb_buffer);
2038         if (!buffer_uptodate(journal->j_sb_buffer)) {
2039                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2040                 goto out_journal;
2041         }
2042         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2043                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2044                                         "user (unsupported) - %d\n",
2045                         be32_to_cpu(journal->j_superblock->s_nr_users));
2046                 goto out_journal;
2047         }
2048         EXT4_SB(sb)->journal_bdev = bdev;
2049         ext4_init_journal_params(sb, journal);
2050         return journal;
2051 out_journal:
2052         jbd2_journal_destroy(journal);
2053 out_bdev:
2054         ext4_blkdev_put(bdev);
2055         return NULL;
2056 }
2057
2058 static int ext4_load_journal(struct super_block *sb,
2059                              struct ext4_super_block *es,
2060                              unsigned long journal_devnum)
2061 {
2062         journal_t *journal;
2063         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2064         dev_t journal_dev;
2065         int err = 0;
2066         int really_read_only;
2067
2068         if (journal_devnum &&
2069             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2070                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2071                         "numbers have changed\n");
2072                 journal_dev = new_decode_dev(journal_devnum);
2073         } else
2074                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2075
2076         really_read_only = bdev_read_only(sb->s_bdev);
2077
2078         /*
2079          * Are we loading a blank journal or performing recovery after a
2080          * crash?  For recovery, we need to check in advance whether we
2081          * can get read-write access to the device.
2082          */
2083
2084         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2085                 if (sb->s_flags & MS_RDONLY) {
2086                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2087                                         "required on readonly filesystem.\n");
2088                         if (really_read_only) {
2089                                 printk(KERN_ERR "EXT4-fs: write access "
2090                                         "unavailable, cannot proceed.\n");
2091                                 return -EROFS;
2092                         }
2093                         printk (KERN_INFO "EXT4-fs: write access will "
2094                                         "be enabled during recovery.\n");
2095                 }
2096         }
2097
2098         if (journal_inum && journal_dev) {
2099                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2100                        "and inode journals!\n");
2101                 return -EINVAL;
2102         }
2103
2104         if (journal_inum) {
2105                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2106                         return -EINVAL;
2107         } else {
2108                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2109                         return -EINVAL;
2110         }
2111
2112         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2113                 err = jbd2_journal_update_format(journal);
2114                 if (err)  {
2115                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2116                         jbd2_journal_destroy(journal);
2117                         return err;
2118                 }
2119         }
2120
2121         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2122                 err = jbd2_journal_wipe(journal, !really_read_only);
2123         if (!err)
2124                 err = jbd2_journal_load(journal);
2125
2126         if (err) {
2127                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2128                 jbd2_journal_destroy(journal);
2129                 return err;
2130         }
2131
2132         EXT4_SB(sb)->s_journal = journal;
2133         ext4_clear_journal_err(sb, es);
2134
2135         if (journal_devnum &&
2136             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2137                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2138                 sb->s_dirt = 1;
2139
2140                 /* Make sure we flush the recovery flag to disk. */
2141                 ext4_commit_super(sb, es, 1);
2142         }
2143
2144         return 0;
2145 }
2146
2147 static int ext4_create_journal(struct super_block * sb,
2148                                struct ext4_super_block * es,
2149                                unsigned int journal_inum)
2150 {
2151         journal_t *journal;
2152
2153         if (sb->s_flags & MS_RDONLY) {
2154                 printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2155                                 "create journal.\n");
2156                 return -EROFS;
2157         }
2158
2159         if (!(journal = ext4_get_journal(sb, journal_inum)))
2160                 return -EINVAL;
2161
2162         printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2163                journal_inum);
2164
2165         if (jbd2_journal_create(journal)) {
2166                 printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2167                 jbd2_journal_destroy(journal);
2168                 return -EIO;
2169         }
2170
2171         EXT4_SB(sb)->s_journal = journal;
2172
2173         ext4_update_dynamic_rev(sb);
2174         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2175         EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2176
2177         es->s_journal_inum = cpu_to_le32(journal_inum);
2178         sb->s_dirt = 1;
2179
2180         /* Make sure we flush the recovery flag to disk. */
2181         ext4_commit_super(sb, es, 1);
2182
2183         return 0;
2184 }
2185
2186 static void ext4_commit_super (struct super_block * sb,
2187                                struct ext4_super_block * es,
2188                                int sync)
2189 {
2190         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2191
2192         if (!sbh)
2193                 return;
2194         es->s_wtime = cpu_to_le32(get_seconds());
2195         ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2196         es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2197         BUFFER_TRACE(sbh, "marking dirty");
2198         mark_buffer_dirty(sbh);
2199         if (sync)
2200                 sync_dirty_buffer(sbh);
2201 }
2202
2203
2204 /*
2205  * Have we just finished recovery?  If so, and if we are mounting (or
2206  * remounting) the filesystem readonly, then we will end up with a
2207  * consistent fs on disk.  Record that fact.
2208  */
2209 static void ext4_mark_recovery_complete(struct super_block * sb,
2210                                         struct ext4_super_block * es)
2211 {
2212         journal_t *journal = EXT4_SB(sb)->s_journal;
2213
2214         jbd2_journal_lock_updates(journal);
2215         jbd2_journal_flush(journal);
2216         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2217             sb->s_flags & MS_RDONLY) {
2218                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2219                 sb->s_dirt = 0;
2220                 ext4_commit_super(sb, es, 1);
2221         }
2222         jbd2_journal_unlock_updates(journal);
2223 }
2224
2225 /*
2226  * If we are mounting (or read-write remounting) a filesystem whose journal
2227  * has recorded an error from a previous lifetime, move that error to the
2228  * main filesystem now.
2229  */
2230 static void ext4_clear_journal_err(struct super_block * sb,
2231                                    struct ext4_super_block * es)
2232 {
2233         journal_t *journal;
2234         int j_errno;
2235         const char *errstr;
2236
2237         journal = EXT4_SB(sb)->s_journal;
2238
2239         /*
2240          * Now check for any error status which may have been recorded in the
2241          * journal by a prior ext4_error() or ext4_abort()
2242          */
2243
2244         j_errno = jbd2_journal_errno(journal);
2245         if (j_errno) {
2246                 char nbuf[16];
2247
2248                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2249                 ext4_warning(sb, __FUNCTION__, "Filesystem error recorded "
2250                              "from previous mount: %s", errstr);
2251                 ext4_warning(sb, __FUNCTION__, "Marking fs in need of "
2252                              "filesystem check.");
2253
2254                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2255                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2256                 ext4_commit_super (sb, es, 1);
2257
2258                 jbd2_journal_clear_err(journal);
2259         }
2260 }
2261
2262 /*
2263  * Force the running and committing transactions to commit,
2264  * and wait on the commit.
2265  */
2266 int ext4_force_commit(struct super_block *sb)
2267 {
2268         journal_t *journal;
2269         int ret;
2270
2271         if (sb->s_flags & MS_RDONLY)
2272                 return 0;
2273
2274         journal = EXT4_SB(sb)->s_journal;
2275         sb->s_dirt = 0;
2276         ret = ext4_journal_force_commit(journal);
2277         return ret;
2278 }
2279
2280 /*
2281  * Ext4 always journals updates to the superblock itself, so we don't
2282  * have to propagate any other updates to the superblock on disk at this
2283  * point.  Just start an async writeback to get the buffers on their way
2284  * to the disk.
2285  *
2286  * This implicitly triggers the writebehind on sync().
2287  */
2288
2289 static void ext4_write_super (struct super_block * sb)
2290 {
2291         if (mutex_trylock(&sb->s_lock) != 0)
2292                 BUG();
2293         sb->s_dirt = 0;
2294 }
2295
2296 static int ext4_sync_fs(struct super_block *sb, int wait)
2297 {
2298         tid_t target;
2299
2300         sb->s_dirt = 0;
2301         if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2302                 if (wait)
2303                         jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2304         }
2305         return 0;
2306 }
2307
2308 /*
2309  * LVM calls this function before a (read-only) snapshot is created.  This
2310  * gives us a chance to flush the journal completely and mark the fs clean.
2311  */
2312 static void ext4_write_super_lockfs(struct super_block *sb)
2313 {
2314         sb->s_dirt = 0;
2315
2316         if (!(sb->s_flags & MS_RDONLY)) {
2317                 journal_t *journal = EXT4_SB(sb)->s_journal;
2318
2319                 /* Now we set up the journal barrier. */
2320                 jbd2_journal_lock_updates(journal);
2321                 jbd2_journal_flush(journal);
2322
2323                 /* Journal blocked and flushed, clear needs_recovery flag. */
2324                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2325                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2326         }
2327 }
2328
2329 /*
2330  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2331  * flag here, even though the filesystem is not technically dirty yet.
2332  */
2333 static void ext4_unlockfs(struct super_block *sb)
2334 {
2335         if (!(sb->s_flags & MS_RDONLY)) {
2336                 lock_super(sb);
2337                 /* Reser the needs_recovery flag before the fs is unlocked. */
2338                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2339                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2340                 unlock_super(sb);
2341                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2342         }
2343 }
2344
2345 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2346 {
2347         struct ext4_super_block * es;
2348         struct ext4_sb_info *sbi = EXT4_SB(sb);
2349         ext4_fsblk_t n_blocks_count = 0;
2350         unsigned long old_sb_flags;
2351         struct ext4_mount_options old_opts;
2352         int err;
2353 #ifdef CONFIG_QUOTA
2354         int i;
2355 #endif
2356
2357         /* Store the original options */
2358         old_sb_flags = sb->s_flags;
2359         old_opts.s_mount_opt = sbi->s_mount_opt;
2360         old_opts.s_resuid = sbi->s_resuid;
2361         old_opts.s_resgid = sbi->s_resgid;
2362         old_opts.s_commit_interval = sbi->s_commit_interval;
2363 #ifdef CONFIG_QUOTA
2364         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2365         for (i = 0; i < MAXQUOTAS; i++)
2366                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2367 #endif
2368
2369         /*
2370          * Allow the "check" option to be passed as a remount option.
2371          */
2372         if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2373                 err = -EINVAL;
2374                 goto restore_opts;
2375         }
2376
2377         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2378                 ext4_abort(sb, __FUNCTION__, "Abort forced by user");
2379
2380         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2381                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2382
2383         es = sbi->s_es;
2384
2385         ext4_init_journal_params(sb, sbi->s_journal);
2386
2387         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2388                 n_blocks_count > ext4_blocks_count(es)) {
2389                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2390                         err = -EROFS;
2391                         goto restore_opts;
2392                 }
2393
2394                 if (*flags & MS_RDONLY) {
2395                         /*
2396                          * First of all, the unconditional stuff we have to do
2397                          * to disable replay of the journal when we next remount
2398                          */
2399                         sb->s_flags |= MS_RDONLY;
2400
2401                         /*
2402                          * OK, test if we are remounting a valid rw partition
2403                          * readonly, and if so set the rdonly flag and then
2404                          * mark the partition as valid again.
2405                          */
2406                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2407                             (sbi->s_mount_state & EXT4_VALID_FS))
2408                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
2409
2410                         ext4_mark_recovery_complete(sb, es);
2411                 } else {
2412                         __le32 ret;
2413                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2414                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2415                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2416                                        "remount RDWR because of unsupported "
2417                                        "optional features (%x).\n",
2418                                        sb->s_id, le32_to_cpu(ret));
2419                                 err = -EROFS;
2420                                 goto restore_opts;
2421                         }
2422
2423                         /*
2424                          * If we have an unprocessed orphan list hanging
2425                          * around from a previously readonly bdev mount,
2426                          * require a full umount/remount for now.
2427                          */
2428                         if (es->s_last_orphan) {
2429                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2430                                        "remount RDWR because of unprocessed "
2431                                        "orphan inode list.  Please "
2432                                        "umount/remount instead.\n",
2433                                        sb->s_id);
2434                                 err = -EINVAL;
2435                                 goto restore_opts;
2436                         }
2437
2438                         /*
2439                          * Mounting a RDONLY partition read-write, so reread
2440                          * and store the current valid flag.  (It may have
2441                          * been changed by e2fsck since we originally mounted
2442                          * the partition.)
2443                          */
2444                         ext4_clear_journal_err(sb, es);
2445                         sbi->s_mount_state = le16_to_cpu(es->s_state);
2446                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2447                                 goto restore_opts;
2448                         if (!ext4_setup_super (sb, es, 0))
2449                                 sb->s_flags &= ~MS_RDONLY;
2450                 }
2451         }
2452 #ifdef CONFIG_QUOTA
2453         /* Release old quota file names */
2454         for (i = 0; i < MAXQUOTAS; i++)
2455                 if (old_opts.s_qf_names[i] &&
2456                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2457                         kfree(old_opts.s_qf_names[i]);
2458 #endif
2459         return 0;
2460 restore_opts:
2461         sb->s_flags = old_sb_flags;
2462         sbi->s_mount_opt = old_opts.s_mount_opt;
2463         sbi->s_resuid = old_opts.s_resuid;
2464         sbi->s_resgid = old_opts.s_resgid;
2465         sbi->s_commit_interval = old_opts.s_commit_interval;
2466 #ifdef CONFIG_QUOTA
2467         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2468         for (i = 0; i < MAXQUOTAS; i++) {
2469                 if (sbi->s_qf_names[i] &&
2470                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2471                         kfree(sbi->s_qf_names[i]);
2472                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2473         }
2474 #endif
2475         return err;
2476 }
2477
2478 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2479 {
2480         struct super_block *sb = dentry->d_sb;
2481         struct ext4_sb_info *sbi = EXT4_SB(sb);
2482         struct ext4_super_block *es = sbi->s_es;
2483         ext4_fsblk_t overhead;
2484         int i;
2485         u64 fsid;
2486
2487         if (test_opt (sb, MINIX_DF))
2488                 overhead = 0;
2489         else {
2490                 unsigned long ngroups;
2491                 ngroups = EXT4_SB(sb)->s_groups_count;
2492                 smp_rmb();
2493
2494                 /*
2495                  * Compute the overhead (FS structures)
2496                  */
2497
2498                 /*
2499                  * All of the blocks before first_data_block are
2500                  * overhead
2501                  */
2502                 overhead = le32_to_cpu(es->s_first_data_block);
2503
2504                 /*
2505                  * Add the overhead attributed to the superblock and
2506                  * block group descriptors.  If the sparse superblocks
2507                  * feature is turned on, then not all groups have this.
2508                  */
2509                 for (i = 0; i < ngroups; i++) {
2510                         overhead += ext4_bg_has_super(sb, i) +
2511                                 ext4_bg_num_gdb(sb, i);
2512                         cond_resched();
2513                 }
2514
2515                 /*
2516                  * Every block group has an inode bitmap, a block
2517                  * bitmap, and an inode table.
2518                  */
2519                 overhead += (ngroups * (2 + EXT4_SB(sb)->s_itb_per_group));
2520         }
2521
2522         buf->f_type = EXT4_SUPER_MAGIC;
2523         buf->f_bsize = sb->s_blocksize;
2524         buf->f_blocks = ext4_blocks_count(es) - overhead;
2525         buf->f_bfree = percpu_counter_sum(&sbi->s_freeblocks_counter);
2526         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2527         if (buf->f_bfree < ext4_r_blocks_count(es))
2528                 buf->f_bavail = 0;
2529         buf->f_files = le32_to_cpu(es->s_inodes_count);
2530         buf->f_ffree = percpu_counter_sum(&sbi->s_freeinodes_counter);
2531         buf->f_namelen = EXT4_NAME_LEN;
2532         fsid = le64_to_cpup((void *)es->s_uuid) ^
2533                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2534         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2535         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2536         return 0;
2537 }
2538
2539 /* Helper function for writing quotas on sync - we need to start transaction before quota file
2540  * is locked for write. Otherwise the are possible deadlocks:
2541  * Process 1                         Process 2
2542  * ext4_create()                     quota_sync()
2543  *   jbd2_journal_start()                   write_dquot()
2544  *   DQUOT_INIT()                        down(dqio_mutex)
2545  *     down(dqio_mutex)                    jbd2_journal_start()
2546  *
2547  */
2548
2549 #ifdef CONFIG_QUOTA
2550
2551 static inline struct inode *dquot_to_inode(struct dquot *dquot)
2552 {
2553         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
2554 }
2555
2556 static int ext4_dquot_initialize(struct inode *inode, int type)
2557 {
2558         handle_t *handle;
2559         int ret, err;
2560
2561         /* We may create quota structure so we need to reserve enough blocks */
2562         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
2563         if (IS_ERR(handle))
2564                 return PTR_ERR(handle);
2565         ret = dquot_initialize(inode, type);
2566         err = ext4_journal_stop(handle);
2567         if (!ret)
2568                 ret = err;
2569         return ret;
2570 }
2571
2572 static int ext4_dquot_drop(struct inode *inode)
2573 {
2574         handle_t *handle;
2575         int ret, err;
2576
2577         /* We may delete quota structure so we need to reserve enough blocks */
2578         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
2579         if (IS_ERR(handle))
2580                 return PTR_ERR(handle);
2581         ret = dquot_drop(inode);
2582         err = ext4_journal_stop(handle);
2583         if (!ret)
2584                 ret = err;
2585         return ret;
2586 }
2587
2588 static int ext4_write_dquot(struct dquot *dquot)
2589 {
2590         int ret, err;
2591         handle_t *handle;
2592         struct inode *inode;
2593
2594         inode = dquot_to_inode(dquot);
2595         handle = ext4_journal_start(inode,
2596                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
2597         if (IS_ERR(handle))
2598                 return PTR_ERR(handle);
2599         ret = dquot_commit(dquot);
2600         err = ext4_journal_stop(handle);
2601         if (!ret)
2602                 ret = err;
2603         return ret;
2604 }
2605
2606 static int ext4_acquire_dquot(struct dquot *dquot)
2607 {
2608         int ret, err;
2609         handle_t *handle;
2610
2611         handle = ext4_journal_start(dquot_to_inode(dquot),
2612                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
2613         if (IS_ERR(handle))
2614                 return PTR_ERR(handle);
2615         ret = dquot_acquire(dquot);
2616         err = ext4_journal_stop(handle);
2617         if (!ret)
2618                 ret = err;
2619         return ret;
2620 }
2621
2622 static int ext4_release_dquot(struct dquot *dquot)
2623 {
2624         int ret, err;
2625         handle_t *handle;
2626
2627         handle = ext4_journal_start(dquot_to_inode(dquot),
2628                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
2629         if (IS_ERR(handle))
2630                 return PTR_ERR(handle);
2631         ret = dquot_release(dquot);
2632         err = ext4_journal_stop(handle);
2633         if (!ret)
2634                 ret = err;
2635         return ret;
2636 }
2637
2638 static int ext4_mark_dquot_dirty(struct dquot *dquot)
2639 {
2640         /* Are we journalling quotas? */
2641         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
2642             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
2643                 dquot_mark_dquot_dirty(dquot);
2644                 return ext4_write_dquot(dquot);
2645         } else {
2646                 return dquot_mark_dquot_dirty(dquot);
2647         }
2648 }
2649
2650 static int ext4_write_info(struct super_block *sb, int type)
2651 {
2652         int ret, err;
2653         handle_t *handle;
2654
2655         /* Data block + inode block */
2656         handle = ext4_journal_start(sb->s_root->d_inode, 2);
2657         if (IS_ERR(handle))
2658                 return PTR_ERR(handle);
2659         ret = dquot_commit_info(sb, type);
2660         err = ext4_journal_stop(handle);
2661         if (!ret)
2662                 ret = err;
2663         return ret;
2664 }
2665
2666 /*
2667  * Turn on quotas during mount time - we need to find
2668  * the quota file and such...
2669  */
2670 static int ext4_quota_on_mount(struct super_block *sb, int type)
2671 {
2672         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
2673                         EXT4_SB(sb)->s_jquota_fmt, type);
2674 }
2675
2676 /*
2677  * Standard function to be called on quota_on
2678  */
2679 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
2680                          char *path)
2681 {
2682         int err;
2683         struct nameidata nd;
2684
2685         if (!test_opt(sb, QUOTA))
2686                 return -EINVAL;
2687         /* Not journalling quota? */
2688         if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
2689             !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
2690                 return vfs_quota_on(sb, type, format_id, path);
2691         err = path_lookup(path, LOOKUP_FOLLOW, &nd);
2692         if (err)
2693                 return err;
2694         /* Quotafile not on the same filesystem? */
2695         if (nd.mnt->mnt_sb != sb) {
2696                 path_release(&nd);
2697                 return -EXDEV;
2698         }
2699         /* Quotafile not of fs root? */
2700         if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
2701                 printk(KERN_WARNING
2702                         "EXT4-fs: Quota file not on filesystem root. "
2703                         "Journalled quota will not work.\n");
2704         path_release(&nd);
2705         return vfs_quota_on(sb, type, format_id, path);
2706 }
2707
2708 /* Read data from quotafile - avoid pagecache and such because we cannot afford
2709  * acquiring the locks... As quota files are never truncated and quota code
2710  * itself serializes the operations (and noone else should touch the files)
2711  * we don't have to be afraid of races */
2712 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
2713                                size_t len, loff_t off)
2714 {
2715         struct inode *inode = sb_dqopt(sb)->files[type];
2716         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2717         int err = 0;
2718         int offset = off & (sb->s_blocksize - 1);
2719         int tocopy;
2720         size_t toread;
2721         struct buffer_head *bh;
2722         loff_t i_size = i_size_read(inode);
2723
2724         if (off > i_size)
2725                 return 0;
2726         if (off+len > i_size)
2727                 len = i_size-off;
2728         toread = len;
2729         while (toread > 0) {
2730                 tocopy = sb->s_blocksize - offset < toread ?
2731                                 sb->s_blocksize - offset : toread;
2732                 bh = ext4_bread(NULL, inode, blk, 0, &err);
2733                 if (err)
2734                         return err;
2735                 if (!bh)        /* A hole? */
2736                         memset(data, 0, tocopy);
2737                 else
2738                         memcpy(data, bh->b_data+offset, tocopy);
2739                 brelse(bh);
2740                 offset = 0;
2741                 toread -= tocopy;
2742                 data += tocopy;
2743                 blk++;
2744         }
2745         return len;
2746 }
2747
2748 /* Write to quotafile (we know the transaction is already started and has
2749  * enough credits) */
2750 static ssize_t ext4_quota_write(struct super_block *sb, int type,
2751                                 const char *data, size_t len, loff_t off)
2752 {
2753         struct inode *inode = sb_dqopt(sb)->files[type];
2754         sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2755         int err = 0;
2756         int offset = off & (sb->s_blocksize - 1);
2757         int tocopy;
2758         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
2759         size_t towrite = len;
2760         struct buffer_head *bh;
2761         handle_t *handle = journal_current_handle();
2762
2763         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2764         while (towrite > 0) {
2765                 tocopy = sb->s_blocksize - offset < towrite ?
2766                                 sb->s_blocksize - offset : towrite;
2767                 bh = ext4_bread(handle, inode, blk, 1, &err);
2768                 if (!bh)
2769                         goto out;
2770                 if (journal_quota) {
2771                         err = ext4_journal_get_write_access(handle, bh);
2772                         if (err) {
2773                                 brelse(bh);
2774                                 goto out;
2775                         }
2776                 }
2777                 lock_buffer(bh);
2778                 memcpy(bh->b_data+offset, data, tocopy);
2779                 flush_dcache_page(bh->b_page);
2780                 unlock_buffer(bh);
2781                 if (journal_quota)
2782                         err = ext4_journal_dirty_metadata(handle, bh);
2783                 else {
2784                         /* Always do at least ordered writes for quotas */
2785                         err = ext4_journal_dirty_data(handle, bh);
2786                         mark_buffer_dirty(bh);
2787                 }
2788                 brelse(bh);
2789                 if (err)
2790                         goto out;
2791                 offset = 0;
2792                 towrite -= tocopy;
2793                 data += tocopy;
2794                 blk++;
2795         }
2796 out:
2797         if (len == towrite)
2798                 return err;
2799         if (inode->i_size < off+len-towrite) {
2800                 i_size_write(inode, off+len-towrite);
2801                 EXT4_I(inode)->i_disksize = inode->i_size;
2802         }
2803         inode->i_version++;
2804         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2805         ext4_mark_inode_dirty(handle, inode);
2806         mutex_unlock(&inode->i_mutex);
2807         return len - towrite;
2808 }
2809
2810 #endif
2811
2812 static int ext4_get_sb(struct file_system_type *fs_type,
2813         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
2814 {
2815         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
2816 }
2817
2818 static struct file_system_type ext4dev_fs_type = {
2819         .owner          = THIS_MODULE,
2820         .name           = "ext4dev",
2821         .get_sb         = ext4_get_sb,
2822         .kill_sb        = kill_block_super,
2823         .fs_flags       = FS_REQUIRES_DEV,
2824 };
2825
2826 static int __init init_ext4_fs(void)
2827 {
2828         int err = init_ext4_xattr();
2829         if (err)
2830                 return err;
2831         err = init_inodecache();
2832         if (err)
2833                 goto out1;
2834         err = register_filesystem(&ext4dev_fs_type);
2835         if (err)
2836                 goto out;
2837         return 0;
2838 out:
2839         destroy_inodecache();
2840 out1:
2841         exit_ext4_xattr();
2842         return err;
2843 }
2844
2845 static void __exit exit_ext4_fs(void)
2846 {
2847         unregister_filesystem(&ext4dev_fs_type);
2848         destroy_inodecache();
2849         exit_ext4_xattr();
2850 }
2851
2852 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
2853 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
2854 MODULE_LICENSE("GPL");
2855 module_init(init_ext4_fs)
2856 module_exit(exit_ext4_fs)