Merge branch 'for-rmk' of git://git.marvell.com/orion
[linux-2.6] / 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/slab.h>
25 #include <linux/init.h>
26 #include <linux/blkdev.h>
27 #include <linux/parser.h>
28 #include <linux/smp_lock.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/proc_fs.h>
38 #include <linux/marker.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <asm/uaccess.h>
42
43 #include "ext4.h"
44 #include "ext4_jbd2.h"
45 #include "xattr.h"
46 #include "acl.h"
47 #include "namei.h"
48 #include "group.h"
49
50 struct proc_dir_entry *ext4_proc_root;
51
52 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
53                              unsigned long journal_devnum);
54 static int ext4_commit_super(struct super_block *sb,
55                               struct ext4_super_block *es, int sync);
56 static void ext4_mark_recovery_complete(struct super_block *sb,
57                                         struct ext4_super_block *es);
58 static void ext4_clear_journal_err(struct super_block *sb,
59                                    struct ext4_super_block *es);
60 static int ext4_sync_fs(struct super_block *sb, int wait);
61 static const char *ext4_decode_error(struct super_block *sb, int errno,
62                                      char nbuf[16]);
63 static int ext4_remount(struct super_block *sb, int *flags, char *data);
64 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
65 static int ext4_unfreeze(struct super_block *sb);
66 static void ext4_write_super(struct super_block *sb);
67 static int ext4_freeze(struct super_block *sb);
68
69
70 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
71                                struct ext4_group_desc *bg)
72 {
73         return le32_to_cpu(bg->bg_block_bitmap_lo) |
74                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
75                 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
76 }
77
78 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
79                                struct ext4_group_desc *bg)
80 {
81         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
82                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
83                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
84 }
85
86 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
87                               struct ext4_group_desc *bg)
88 {
89         return le32_to_cpu(bg->bg_inode_table_lo) |
90                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
91                 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
92 }
93
94 __u32 ext4_free_blks_count(struct super_block *sb,
95                               struct ext4_group_desc *bg)
96 {
97         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
98                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
99                 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
100 }
101
102 __u32 ext4_free_inodes_count(struct super_block *sb,
103                               struct ext4_group_desc *bg)
104 {
105         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
106                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
107                 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
108 }
109
110 __u32 ext4_used_dirs_count(struct super_block *sb,
111                               struct ext4_group_desc *bg)
112 {
113         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
114                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
115                 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
116 }
117
118 __u32 ext4_itable_unused_count(struct super_block *sb,
119                               struct ext4_group_desc *bg)
120 {
121         return le16_to_cpu(bg->bg_itable_unused_lo) |
122                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
123                 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
124 }
125
126 void ext4_block_bitmap_set(struct super_block *sb,
127                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
128 {
129         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
130         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
131                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
132 }
133
134 void ext4_inode_bitmap_set(struct super_block *sb,
135                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
136 {
137         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
138         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
139                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
140 }
141
142 void ext4_inode_table_set(struct super_block *sb,
143                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
144 {
145         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
146         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
147                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
148 }
149
150 void ext4_free_blks_set(struct super_block *sb,
151                           struct ext4_group_desc *bg, __u32 count)
152 {
153         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
154         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
155                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
156 }
157
158 void ext4_free_inodes_set(struct super_block *sb,
159                           struct ext4_group_desc *bg, __u32 count)
160 {
161         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
162         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
163                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
164 }
165
166 void ext4_used_dirs_set(struct super_block *sb,
167                           struct ext4_group_desc *bg, __u32 count)
168 {
169         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
170         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
171                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
172 }
173
174 void ext4_itable_unused_set(struct super_block *sb,
175                           struct ext4_group_desc *bg, __u32 count)
176 {
177         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
178         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
179                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
180 }
181
182 /*
183  * Wrappers for jbd2_journal_start/end.
184  *
185  * The only special thing we need to do here is to make sure that all
186  * journal_end calls result in the superblock being marked dirty, so
187  * that sync() will call the filesystem's write_super callback if
188  * appropriate.
189  */
190 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
191 {
192         journal_t *journal;
193
194         if (sb->s_flags & MS_RDONLY)
195                 return ERR_PTR(-EROFS);
196
197         /* Special case here: if the journal has aborted behind our
198          * backs (eg. EIO in the commit thread), then we still need to
199          * take the FS itself readonly cleanly. */
200         journal = EXT4_SB(sb)->s_journal;
201         if (journal) {
202                 if (is_journal_aborted(journal)) {
203                         ext4_abort(sb, __func__,
204                                    "Detected aborted journal");
205                         return ERR_PTR(-EROFS);
206                 }
207                 return jbd2_journal_start(journal, nblocks);
208         }
209         /*
210          * We're not journaling, return the appropriate indication.
211          */
212         current->journal_info = EXT4_NOJOURNAL_HANDLE;
213         return current->journal_info;
214 }
215
216 /*
217  * The only special thing we need to do here is to make sure that all
218  * jbd2_journal_stop calls result in the superblock being marked dirty, so
219  * that sync() will call the filesystem's write_super callback if
220  * appropriate.
221  */
222 int __ext4_journal_stop(const char *where, handle_t *handle)
223 {
224         struct super_block *sb;
225         int err;
226         int rc;
227
228         if (!ext4_handle_valid(handle)) {
229                 /*
230                  * Do this here since we don't call jbd2_journal_stop() in
231                  * no-journal mode.
232                  */
233                 current->journal_info = NULL;
234                 return 0;
235         }
236         sb = handle->h_transaction->t_journal->j_private;
237         err = handle->h_err;
238         rc = jbd2_journal_stop(handle);
239
240         if (!err)
241                 err = rc;
242         if (err)
243                 __ext4_std_error(sb, where, err);
244         return err;
245 }
246
247 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
248                 struct buffer_head *bh, handle_t *handle, int err)
249 {
250         char nbuf[16];
251         const char *errstr = ext4_decode_error(NULL, err, nbuf);
252
253         BUG_ON(!ext4_handle_valid(handle));
254
255         if (bh)
256                 BUFFER_TRACE(bh, "abort");
257
258         if (!handle->h_err)
259                 handle->h_err = err;
260
261         if (is_handle_aborted(handle))
262                 return;
263
264         printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
265                caller, errstr, err_fn);
266
267         jbd2_journal_abort_handle(handle);
268 }
269
270 /* Deal with the reporting of failure conditions on a filesystem such as
271  * inconsistencies detected or read IO failures.
272  *
273  * On ext2, we can store the error state of the filesystem in the
274  * superblock.  That is not possible on ext4, because we may have other
275  * write ordering constraints on the superblock which prevent us from
276  * writing it out straight away; and given that the journal is about to
277  * be aborted, we can't rely on the current, or future, transactions to
278  * write out the superblock safely.
279  *
280  * We'll just use the jbd2_journal_abort() error code to record an error in
281  * the journal instead.  On recovery, the journal will compain about
282  * that error until we've noted it down and cleared it.
283  */
284
285 static void ext4_handle_error(struct super_block *sb)
286 {
287         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
288
289         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
290         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
291
292         if (sb->s_flags & MS_RDONLY)
293                 return;
294
295         if (!test_opt(sb, ERRORS_CONT)) {
296                 journal_t *journal = EXT4_SB(sb)->s_journal;
297
298                 EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
299                 if (journal)
300                         jbd2_journal_abort(journal, -EIO);
301         }
302         if (test_opt(sb, ERRORS_RO)) {
303                 printk(KERN_CRIT "Remounting filesystem read-only\n");
304                 sb->s_flags |= MS_RDONLY;
305         }
306         ext4_commit_super(sb, es, 1);
307         if (test_opt(sb, ERRORS_PANIC))
308                 panic("EXT4-fs (device %s): panic forced after error\n",
309                         sb->s_id);
310 }
311
312 void ext4_error(struct super_block *sb, const char *function,
313                 const char *fmt, ...)
314 {
315         va_list args;
316
317         va_start(args, fmt);
318         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
319         vprintk(fmt, args);
320         printk("\n");
321         va_end(args);
322
323         ext4_handle_error(sb);
324 }
325
326 static const char *ext4_decode_error(struct super_block *sb, int errno,
327                                      char nbuf[16])
328 {
329         char *errstr = NULL;
330
331         switch (errno) {
332         case -EIO:
333                 errstr = "IO failure";
334                 break;
335         case -ENOMEM:
336                 errstr = "Out of memory";
337                 break;
338         case -EROFS:
339                 if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
340                         errstr = "Journal has aborted";
341                 else
342                         errstr = "Readonly filesystem";
343                 break;
344         default:
345                 /* If the caller passed in an extra buffer for unknown
346                  * errors, textualise them now.  Else we just return
347                  * NULL. */
348                 if (nbuf) {
349                         /* Check for truncated error codes... */
350                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
351                                 errstr = nbuf;
352                 }
353                 break;
354         }
355
356         return errstr;
357 }
358
359 /* __ext4_std_error decodes expected errors from journaling functions
360  * automatically and invokes the appropriate error response.  */
361
362 void __ext4_std_error(struct super_block *sb, const char *function, int errno)
363 {
364         char nbuf[16];
365         const char *errstr;
366
367         /* Special case: if the error is EROFS, and we're not already
368          * inside a transaction, then there's really no point in logging
369          * an error. */
370         if (errno == -EROFS && journal_current_handle() == NULL &&
371             (sb->s_flags & MS_RDONLY))
372                 return;
373
374         errstr = ext4_decode_error(sb, errno, nbuf);
375         printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
376                sb->s_id, function, errstr);
377
378         ext4_handle_error(sb);
379 }
380
381 /*
382  * ext4_abort is a much stronger failure handler than ext4_error.  The
383  * abort function may be used to deal with unrecoverable failures such
384  * as journal IO errors or ENOMEM at a critical moment in log management.
385  *
386  * We unconditionally force the filesystem into an ABORT|READONLY state,
387  * unless the error response on the fs has been set to panic in which
388  * case we take the easy way out and panic immediately.
389  */
390
391 void ext4_abort(struct super_block *sb, const char *function,
392                 const char *fmt, ...)
393 {
394         va_list args;
395
396         printk(KERN_CRIT "ext4_abort called.\n");
397
398         va_start(args, fmt);
399         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
400         vprintk(fmt, args);
401         printk("\n");
402         va_end(args);
403
404         if (test_opt(sb, ERRORS_PANIC))
405                 panic("EXT4-fs panic from previous error\n");
406
407         if (sb->s_flags & MS_RDONLY)
408                 return;
409
410         printk(KERN_CRIT "Remounting filesystem read-only\n");
411         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
412         sb->s_flags |= MS_RDONLY;
413         EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
414         if (EXT4_SB(sb)->s_journal)
415                 jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
416 }
417
418 void ext4_warning(struct super_block *sb, const char *function,
419                   const char *fmt, ...)
420 {
421         va_list args;
422
423         va_start(args, fmt);
424         printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
425                sb->s_id, function);
426         vprintk(fmt, args);
427         printk("\n");
428         va_end(args);
429 }
430
431 void ext4_grp_locked_error(struct super_block *sb, ext4_group_t grp,
432                                 const char *function, const char *fmt, ...)
433 __releases(bitlock)
434 __acquires(bitlock)
435 {
436         va_list args;
437         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
438
439         va_start(args, fmt);
440         printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
441         vprintk(fmt, args);
442         printk("\n");
443         va_end(args);
444
445         if (test_opt(sb, ERRORS_CONT)) {
446                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
447                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
448                 ext4_commit_super(sb, es, 0);
449                 return;
450         }
451         ext4_unlock_group(sb, grp);
452         ext4_handle_error(sb);
453         /*
454          * We only get here in the ERRORS_RO case; relocking the group
455          * may be dangerous, but nothing bad will happen since the
456          * filesystem will have already been marked read/only and the
457          * journal has been aborted.  We return 1 as a hint to callers
458          * who might what to use the return value from
459          * ext4_grp_locked_error() to distinguish beween the
460          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
461          * aggressively from the ext4 function in question, with a
462          * more appropriate error code.
463          */
464         ext4_lock_group(sb, grp);
465         return;
466 }
467
468
469 void ext4_update_dynamic_rev(struct super_block *sb)
470 {
471         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
472
473         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
474                 return;
475
476         ext4_warning(sb, __func__,
477                      "updating to rev %d because of new feature flag, "
478                      "running e2fsck is recommended",
479                      EXT4_DYNAMIC_REV);
480
481         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
482         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
483         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
484         /* leave es->s_feature_*compat flags alone */
485         /* es->s_uuid will be set by e2fsck if empty */
486
487         /*
488          * The rest of the superblock fields should be zero, and if not it
489          * means they are likely already in use, so leave them alone.  We
490          * can leave it up to e2fsck to clean up any inconsistencies there.
491          */
492 }
493
494 /*
495  * Open the external journal device
496  */
497 static struct block_device *ext4_blkdev_get(dev_t dev)
498 {
499         struct block_device *bdev;
500         char b[BDEVNAME_SIZE];
501
502         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
503         if (IS_ERR(bdev))
504                 goto fail;
505         return bdev;
506
507 fail:
508         printk(KERN_ERR "EXT4-fs: failed to open journal device %s: %ld\n",
509                         __bdevname(dev, b), PTR_ERR(bdev));
510         return NULL;
511 }
512
513 /*
514  * Release the journal device
515  */
516 static int ext4_blkdev_put(struct block_device *bdev)
517 {
518         bd_release(bdev);
519         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
520 }
521
522 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
523 {
524         struct block_device *bdev;
525         int ret = -ENODEV;
526
527         bdev = sbi->journal_bdev;
528         if (bdev) {
529                 ret = ext4_blkdev_put(bdev);
530                 sbi->journal_bdev = NULL;
531         }
532         return ret;
533 }
534
535 static inline struct inode *orphan_list_entry(struct list_head *l)
536 {
537         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
538 }
539
540 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
541 {
542         struct list_head *l;
543
544         printk(KERN_ERR "sb orphan head is %d\n",
545                le32_to_cpu(sbi->s_es->s_last_orphan));
546
547         printk(KERN_ERR "sb_info orphan list:\n");
548         list_for_each(l, &sbi->s_orphan) {
549                 struct inode *inode = orphan_list_entry(l);
550                 printk(KERN_ERR "  "
551                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
552                        inode->i_sb->s_id, inode->i_ino, inode,
553                        inode->i_mode, inode->i_nlink,
554                        NEXT_ORPHAN(inode));
555         }
556 }
557
558 static void ext4_put_super(struct super_block *sb)
559 {
560         struct ext4_sb_info *sbi = EXT4_SB(sb);
561         struct ext4_super_block *es = sbi->s_es;
562         int i, err;
563
564         ext4_mb_release(sb);
565         ext4_ext_release(sb);
566         ext4_xattr_put_super(sb);
567         if (sbi->s_journal) {
568                 err = jbd2_journal_destroy(sbi->s_journal);
569                 sbi->s_journal = NULL;
570                 if (err < 0)
571                         ext4_abort(sb, __func__,
572                                    "Couldn't clean up the journal");
573         }
574         if (!(sb->s_flags & MS_RDONLY)) {
575                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
576                 es->s_state = cpu_to_le16(sbi->s_mount_state);
577                 ext4_commit_super(sb, es, 1);
578         }
579         if (sbi->s_proc) {
580                 remove_proc_entry("inode_readahead_blks", sbi->s_proc);
581                 remove_proc_entry(sb->s_id, ext4_proc_root);
582         }
583
584         for (i = 0; i < sbi->s_gdb_count; i++)
585                 brelse(sbi->s_group_desc[i]);
586         kfree(sbi->s_group_desc);
587         kfree(sbi->s_flex_groups);
588         percpu_counter_destroy(&sbi->s_freeblocks_counter);
589         percpu_counter_destroy(&sbi->s_freeinodes_counter);
590         percpu_counter_destroy(&sbi->s_dirs_counter);
591         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
592         brelse(sbi->s_sbh);
593 #ifdef CONFIG_QUOTA
594         for (i = 0; i < MAXQUOTAS; i++)
595                 kfree(sbi->s_qf_names[i]);
596 #endif
597
598         /* Debugging code just in case the in-memory inode orphan list
599          * isn't empty.  The on-disk one can be non-empty if we've
600          * detected an error and taken the fs readonly, but the
601          * in-memory list had better be clean by this point. */
602         if (!list_empty(&sbi->s_orphan))
603                 dump_orphan_list(sb, sbi);
604         J_ASSERT(list_empty(&sbi->s_orphan));
605
606         invalidate_bdev(sb->s_bdev);
607         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
608                 /*
609                  * Invalidate the journal device's buffers.  We don't want them
610                  * floating about in memory - the physical journal device may
611                  * hotswapped, and it breaks the `ro-after' testing code.
612                  */
613                 sync_blockdev(sbi->journal_bdev);
614                 invalidate_bdev(sbi->journal_bdev);
615                 ext4_blkdev_remove(sbi);
616         }
617         sb->s_fs_info = NULL;
618         kfree(sbi);
619         return;
620 }
621
622 static struct kmem_cache *ext4_inode_cachep;
623
624 /*
625  * Called inside transaction, so use GFP_NOFS
626  */
627 static struct inode *ext4_alloc_inode(struct super_block *sb)
628 {
629         struct ext4_inode_info *ei;
630
631         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
632         if (!ei)
633                 return NULL;
634 #ifdef CONFIG_EXT4_FS_POSIX_ACL
635         ei->i_acl = EXT4_ACL_NOT_CACHED;
636         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
637 #endif
638         ei->vfs_inode.i_version = 1;
639         ei->vfs_inode.i_data.writeback_index = 0;
640         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
641         INIT_LIST_HEAD(&ei->i_prealloc_list);
642         spin_lock_init(&ei->i_prealloc_lock);
643         /*
644          * Note:  We can be called before EXT4_SB(sb)->s_journal is set,
645          * therefore it can be null here.  Don't check it, just initialize
646          * jinode.
647          */
648         jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
649         ei->i_reserved_data_blocks = 0;
650         ei->i_reserved_meta_blocks = 0;
651         ei->i_allocated_meta_blocks = 0;
652         ei->i_delalloc_reserved_flag = 0;
653         spin_lock_init(&(ei->i_block_reservation_lock));
654         return &ei->vfs_inode;
655 }
656
657 static void ext4_destroy_inode(struct inode *inode)
658 {
659         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
660                 printk("EXT4 Inode %p: orphan list check failed!\n",
661                         EXT4_I(inode));
662                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
663                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
664                                 true);
665                 dump_stack();
666         }
667         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
668 }
669
670 static void init_once(void *foo)
671 {
672         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
673
674         INIT_LIST_HEAD(&ei->i_orphan);
675 #ifdef CONFIG_EXT4_FS_XATTR
676         init_rwsem(&ei->xattr_sem);
677 #endif
678         init_rwsem(&ei->i_data_sem);
679         inode_init_once(&ei->vfs_inode);
680 }
681
682 static int init_inodecache(void)
683 {
684         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
685                                              sizeof(struct ext4_inode_info),
686                                              0, (SLAB_RECLAIM_ACCOUNT|
687                                                 SLAB_MEM_SPREAD),
688                                              init_once);
689         if (ext4_inode_cachep == NULL)
690                 return -ENOMEM;
691         return 0;
692 }
693
694 static void destroy_inodecache(void)
695 {
696         kmem_cache_destroy(ext4_inode_cachep);
697 }
698
699 static void ext4_clear_inode(struct inode *inode)
700 {
701 #ifdef CONFIG_EXT4_FS_POSIX_ACL
702         if (EXT4_I(inode)->i_acl &&
703                         EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
704                 posix_acl_release(EXT4_I(inode)->i_acl);
705                 EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
706         }
707         if (EXT4_I(inode)->i_default_acl &&
708                         EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
709                 posix_acl_release(EXT4_I(inode)->i_default_acl);
710                 EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
711         }
712 #endif
713         ext4_discard_preallocations(inode);
714         if (EXT4_JOURNAL(inode))
715                 jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
716                                        &EXT4_I(inode)->jinode);
717 }
718
719 static inline void ext4_show_quota_options(struct seq_file *seq,
720                                            struct super_block *sb)
721 {
722 #if defined(CONFIG_QUOTA)
723         struct ext4_sb_info *sbi = EXT4_SB(sb);
724
725         if (sbi->s_jquota_fmt)
726                 seq_printf(seq, ",jqfmt=%s",
727                 (sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold" : "vfsv0");
728
729         if (sbi->s_qf_names[USRQUOTA])
730                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
731
732         if (sbi->s_qf_names[GRPQUOTA])
733                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
734
735         if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
736                 seq_puts(seq, ",usrquota");
737
738         if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
739                 seq_puts(seq, ",grpquota");
740 #endif
741 }
742
743 /*
744  * Show an option if
745  *  - it's set to a non-default value OR
746  *  - if the per-sb default is different from the global default
747  */
748 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
749 {
750         int def_errors;
751         unsigned long def_mount_opts;
752         struct super_block *sb = vfs->mnt_sb;
753         struct ext4_sb_info *sbi = EXT4_SB(sb);
754         struct ext4_super_block *es = sbi->s_es;
755
756         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
757         def_errors     = le16_to_cpu(es->s_errors);
758
759         if (sbi->s_sb_block != 1)
760                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
761         if (test_opt(sb, MINIX_DF))
762                 seq_puts(seq, ",minixdf");
763         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
764                 seq_puts(seq, ",grpid");
765         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
766                 seq_puts(seq, ",nogrpid");
767         if (sbi->s_resuid != EXT4_DEF_RESUID ||
768             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
769                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
770         }
771         if (sbi->s_resgid != EXT4_DEF_RESGID ||
772             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
773                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
774         }
775         if (test_opt(sb, ERRORS_RO)) {
776                 if (def_errors == EXT4_ERRORS_PANIC ||
777                     def_errors == EXT4_ERRORS_CONTINUE) {
778                         seq_puts(seq, ",errors=remount-ro");
779                 }
780         }
781         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
782                 seq_puts(seq, ",errors=continue");
783         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
784                 seq_puts(seq, ",errors=panic");
785         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
786                 seq_puts(seq, ",nouid32");
787         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
788                 seq_puts(seq, ",debug");
789         if (test_opt(sb, OLDALLOC))
790                 seq_puts(seq, ",oldalloc");
791 #ifdef CONFIG_EXT4_FS_XATTR
792         if (test_opt(sb, XATTR_USER) &&
793                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
794                 seq_puts(seq, ",user_xattr");
795         if (!test_opt(sb, XATTR_USER) &&
796             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
797                 seq_puts(seq, ",nouser_xattr");
798         }
799 #endif
800 #ifdef CONFIG_EXT4_FS_POSIX_ACL
801         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
802                 seq_puts(seq, ",acl");
803         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
804                 seq_puts(seq, ",noacl");
805 #endif
806         if (!test_opt(sb, RESERVATION))
807                 seq_puts(seq, ",noreservation");
808         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
809                 seq_printf(seq, ",commit=%u",
810                            (unsigned) (sbi->s_commit_interval / HZ));
811         }
812         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
813                 seq_printf(seq, ",min_batch_time=%u",
814                            (unsigned) sbi->s_min_batch_time);
815         }
816         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
817                 seq_printf(seq, ",max_batch_time=%u",
818                            (unsigned) sbi->s_min_batch_time);
819         }
820
821         /*
822          * We're changing the default of barrier mount option, so
823          * let's always display its mount state so it's clear what its
824          * status is.
825          */
826         seq_puts(seq, ",barrier=");
827         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
828         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
829                 seq_puts(seq, ",journal_async_commit");
830         if (test_opt(sb, NOBH))
831                 seq_puts(seq, ",nobh");
832         if (test_opt(sb, I_VERSION))
833                 seq_puts(seq, ",i_version");
834         if (!test_opt(sb, DELALLOC))
835                 seq_puts(seq, ",nodelalloc");
836
837
838         if (sbi->s_stripe)
839                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
840         /*
841          * journal mode get enabled in different ways
842          * So just print the value even if we didn't specify it
843          */
844         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
845                 seq_puts(seq, ",data=journal");
846         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
847                 seq_puts(seq, ",data=ordered");
848         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
849                 seq_puts(seq, ",data=writeback");
850
851         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
852                 seq_printf(seq, ",inode_readahead_blks=%u",
853                            sbi->s_inode_readahead_blks);
854
855         if (test_opt(sb, DATA_ERR_ABORT))
856                 seq_puts(seq, ",data_err=abort");
857
858         ext4_show_quota_options(seq, sb);
859         return 0;
860 }
861
862
863 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
864                 u64 ino, u32 generation)
865 {
866         struct inode *inode;
867
868         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
869                 return ERR_PTR(-ESTALE);
870         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
871                 return ERR_PTR(-ESTALE);
872
873         /* iget isn't really right if the inode is currently unallocated!!
874          *
875          * ext4_read_inode will return a bad_inode if the inode had been
876          * deleted, so we should be safe.
877          *
878          * Currently we don't know the generation for parent directory, so
879          * a generation of 0 means "accept any"
880          */
881         inode = ext4_iget(sb, ino);
882         if (IS_ERR(inode))
883                 return ERR_CAST(inode);
884         if (generation && inode->i_generation != generation) {
885                 iput(inode);
886                 return ERR_PTR(-ESTALE);
887         }
888
889         return inode;
890 }
891
892 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
893                 int fh_len, int fh_type)
894 {
895         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
896                                     ext4_nfs_get_inode);
897 }
898
899 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
900                 int fh_len, int fh_type)
901 {
902         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
903                                     ext4_nfs_get_inode);
904 }
905
906 /*
907  * Try to release metadata pages (indirect blocks, directories) which are
908  * mapped via the block device.  Since these pages could have journal heads
909  * which would prevent try_to_free_buffers() from freeing them, we must use
910  * jbd2 layer's try_to_free_buffers() function to release them.
911  */
912 static int bdev_try_to_free_page(struct super_block *sb, struct page *page, gfp_t wait)
913 {
914         journal_t *journal = EXT4_SB(sb)->s_journal;
915
916         WARN_ON(PageChecked(page));
917         if (!page_has_buffers(page))
918                 return 0;
919         if (journal)
920                 return jbd2_journal_try_to_free_buffers(journal, page,
921                                                         wait & ~__GFP_WAIT);
922         return try_to_free_buffers(page);
923 }
924
925 #ifdef CONFIG_QUOTA
926 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
927 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
928
929 static int ext4_dquot_initialize(struct inode *inode, int type);
930 static int ext4_dquot_drop(struct inode *inode);
931 static int ext4_write_dquot(struct dquot *dquot);
932 static int ext4_acquire_dquot(struct dquot *dquot);
933 static int ext4_release_dquot(struct dquot *dquot);
934 static int ext4_mark_dquot_dirty(struct dquot *dquot);
935 static int ext4_write_info(struct super_block *sb, int type);
936 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
937                                 char *path, int remount);
938 static int ext4_quota_on_mount(struct super_block *sb, int type);
939 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
940                                size_t len, loff_t off);
941 static ssize_t ext4_quota_write(struct super_block *sb, int type,
942                                 const char *data, size_t len, loff_t off);
943
944 static struct dquot_operations ext4_quota_operations = {
945         .initialize     = ext4_dquot_initialize,
946         .drop           = ext4_dquot_drop,
947         .alloc_space    = dquot_alloc_space,
948         .alloc_inode    = dquot_alloc_inode,
949         .free_space     = dquot_free_space,
950         .free_inode     = dquot_free_inode,
951         .transfer       = dquot_transfer,
952         .write_dquot    = ext4_write_dquot,
953         .acquire_dquot  = ext4_acquire_dquot,
954         .release_dquot  = ext4_release_dquot,
955         .mark_dirty     = ext4_mark_dquot_dirty,
956         .write_info     = ext4_write_info,
957         .alloc_dquot    = dquot_alloc,
958         .destroy_dquot  = dquot_destroy,
959 };
960
961 static struct quotactl_ops ext4_qctl_operations = {
962         .quota_on       = ext4_quota_on,
963         .quota_off      = vfs_quota_off,
964         .quota_sync     = vfs_quota_sync,
965         .get_info       = vfs_get_dqinfo,
966         .set_info       = vfs_set_dqinfo,
967         .get_dqblk      = vfs_get_dqblk,
968         .set_dqblk      = vfs_set_dqblk
969 };
970 #endif
971
972 static const struct super_operations ext4_sops = {
973         .alloc_inode    = ext4_alloc_inode,
974         .destroy_inode  = ext4_destroy_inode,
975         .write_inode    = ext4_write_inode,
976         .dirty_inode    = ext4_dirty_inode,
977         .delete_inode   = ext4_delete_inode,
978         .put_super      = ext4_put_super,
979         .write_super    = ext4_write_super,
980         .sync_fs        = ext4_sync_fs,
981         .freeze_fs      = ext4_freeze,
982         .unfreeze_fs    = ext4_unfreeze,
983         .statfs         = ext4_statfs,
984         .remount_fs     = ext4_remount,
985         .clear_inode    = ext4_clear_inode,
986         .show_options   = ext4_show_options,
987 #ifdef CONFIG_QUOTA
988         .quota_read     = ext4_quota_read,
989         .quota_write    = ext4_quota_write,
990 #endif
991         .bdev_try_to_free_page = bdev_try_to_free_page,
992 };
993
994 static const struct export_operations ext4_export_ops = {
995         .fh_to_dentry = ext4_fh_to_dentry,
996         .fh_to_parent = ext4_fh_to_parent,
997         .get_parent = ext4_get_parent,
998 };
999
1000 enum {
1001         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1002         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1003         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1004         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1005         Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
1006         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1007         Opt_journal_update, Opt_journal_dev,
1008         Opt_journal_checksum, Opt_journal_async_commit,
1009         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1010         Opt_data_err_abort, Opt_data_err_ignore,
1011         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1012         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
1013         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
1014         Opt_grpquota, Opt_i_version,
1015         Opt_stripe, Opt_delalloc, Opt_nodelalloc,
1016         Opt_inode_readahead_blks, Opt_journal_ioprio
1017 };
1018
1019 static const match_table_t tokens = {
1020         {Opt_bsd_df, "bsddf"},
1021         {Opt_minix_df, "minixdf"},
1022         {Opt_grpid, "grpid"},
1023         {Opt_grpid, "bsdgroups"},
1024         {Opt_nogrpid, "nogrpid"},
1025         {Opt_nogrpid, "sysvgroups"},
1026         {Opt_resgid, "resgid=%u"},
1027         {Opt_resuid, "resuid=%u"},
1028         {Opt_sb, "sb=%u"},
1029         {Opt_err_cont, "errors=continue"},
1030         {Opt_err_panic, "errors=panic"},
1031         {Opt_err_ro, "errors=remount-ro"},
1032         {Opt_nouid32, "nouid32"},
1033         {Opt_debug, "debug"},
1034         {Opt_oldalloc, "oldalloc"},
1035         {Opt_orlov, "orlov"},
1036         {Opt_user_xattr, "user_xattr"},
1037         {Opt_nouser_xattr, "nouser_xattr"},
1038         {Opt_acl, "acl"},
1039         {Opt_noacl, "noacl"},
1040         {Opt_reservation, "reservation"},
1041         {Opt_noreservation, "noreservation"},
1042         {Opt_noload, "noload"},
1043         {Opt_nobh, "nobh"},
1044         {Opt_bh, "bh"},
1045         {Opt_commit, "commit=%u"},
1046         {Opt_min_batch_time, "min_batch_time=%u"},
1047         {Opt_max_batch_time, "max_batch_time=%u"},
1048         {Opt_journal_update, "journal=update"},
1049         {Opt_journal_dev, "journal_dev=%u"},
1050         {Opt_journal_checksum, "journal_checksum"},
1051         {Opt_journal_async_commit, "journal_async_commit"},
1052         {Opt_abort, "abort"},
1053         {Opt_data_journal, "data=journal"},
1054         {Opt_data_ordered, "data=ordered"},
1055         {Opt_data_writeback, "data=writeback"},
1056         {Opt_data_err_abort, "data_err=abort"},
1057         {Opt_data_err_ignore, "data_err=ignore"},
1058         {Opt_offusrjquota, "usrjquota="},
1059         {Opt_usrjquota, "usrjquota=%s"},
1060         {Opt_offgrpjquota, "grpjquota="},
1061         {Opt_grpjquota, "grpjquota=%s"},
1062         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1063         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1064         {Opt_grpquota, "grpquota"},
1065         {Opt_noquota, "noquota"},
1066         {Opt_quota, "quota"},
1067         {Opt_usrquota, "usrquota"},
1068         {Opt_barrier, "barrier=%u"},
1069         {Opt_i_version, "i_version"},
1070         {Opt_stripe, "stripe=%u"},
1071         {Opt_resize, "resize"},
1072         {Opt_delalloc, "delalloc"},
1073         {Opt_nodelalloc, "nodelalloc"},
1074         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1075         {Opt_journal_ioprio, "journal_ioprio=%u"},
1076         {Opt_err, NULL},
1077 };
1078
1079 static ext4_fsblk_t get_sb_block(void **data)
1080 {
1081         ext4_fsblk_t    sb_block;
1082         char            *options = (char *) *data;
1083
1084         if (!options || strncmp(options, "sb=", 3) != 0)
1085                 return 1;       /* Default location */
1086         options += 3;
1087         /*todo: use simple_strtoll with >32bit ext4 */
1088         sb_block = simple_strtoul(options, &options, 0);
1089         if (*options && *options != ',') {
1090                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1091                        (char *) *data);
1092                 return 1;
1093         }
1094         if (*options == ',')
1095                 options++;
1096         *data = (void *) options;
1097         return sb_block;
1098 }
1099
1100 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1101
1102 static int parse_options(char *options, struct super_block *sb,
1103                          unsigned long *journal_devnum,
1104                          unsigned int *journal_ioprio,
1105                          ext4_fsblk_t *n_blocks_count, int is_remount)
1106 {
1107         struct ext4_sb_info *sbi = EXT4_SB(sb);
1108         char *p;
1109         substring_t args[MAX_OPT_ARGS];
1110         int data_opt = 0;
1111         int option;
1112 #ifdef CONFIG_QUOTA
1113         int qtype, qfmt;
1114         char *qname;
1115 #endif
1116
1117         if (!options)
1118                 return 1;
1119
1120         while ((p = strsep(&options, ",")) != NULL) {
1121                 int token;
1122                 if (!*p)
1123                         continue;
1124
1125                 token = match_token(p, tokens, args);
1126                 switch (token) {
1127                 case Opt_bsd_df:
1128                         clear_opt(sbi->s_mount_opt, MINIX_DF);
1129                         break;
1130                 case Opt_minix_df:
1131                         set_opt(sbi->s_mount_opt, MINIX_DF);
1132                         break;
1133                 case Opt_grpid:
1134                         set_opt(sbi->s_mount_opt, GRPID);
1135                         break;
1136                 case Opt_nogrpid:
1137                         clear_opt(sbi->s_mount_opt, GRPID);
1138                         break;
1139                 case Opt_resuid:
1140                         if (match_int(&args[0], &option))
1141                                 return 0;
1142                         sbi->s_resuid = option;
1143                         break;
1144                 case Opt_resgid:
1145                         if (match_int(&args[0], &option))
1146                                 return 0;
1147                         sbi->s_resgid = option;
1148                         break;
1149                 case Opt_sb:
1150                         /* handled by get_sb_block() instead of here */
1151                         /* *sb_block = match_int(&args[0]); */
1152                         break;
1153                 case Opt_err_panic:
1154                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1155                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1156                         set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1157                         break;
1158                 case Opt_err_ro:
1159                         clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1160                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1161                         set_opt(sbi->s_mount_opt, ERRORS_RO);
1162                         break;
1163                 case Opt_err_cont:
1164                         clear_opt(sbi->s_mount_opt, ERRORS_RO);
1165                         clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1166                         set_opt(sbi->s_mount_opt, ERRORS_CONT);
1167                         break;
1168                 case Opt_nouid32:
1169                         set_opt(sbi->s_mount_opt, NO_UID32);
1170                         break;
1171                 case Opt_debug:
1172                         set_opt(sbi->s_mount_opt, DEBUG);
1173                         break;
1174                 case Opt_oldalloc:
1175                         set_opt(sbi->s_mount_opt, OLDALLOC);
1176                         break;
1177                 case Opt_orlov:
1178                         clear_opt(sbi->s_mount_opt, OLDALLOC);
1179                         break;
1180 #ifdef CONFIG_EXT4_FS_XATTR
1181                 case Opt_user_xattr:
1182                         set_opt(sbi->s_mount_opt, XATTR_USER);
1183                         break;
1184                 case Opt_nouser_xattr:
1185                         clear_opt(sbi->s_mount_opt, XATTR_USER);
1186                         break;
1187 #else
1188                 case Opt_user_xattr:
1189                 case Opt_nouser_xattr:
1190                         printk(KERN_ERR "EXT4 (no)user_xattr options "
1191                                "not supported\n");
1192                         break;
1193 #endif
1194 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1195                 case Opt_acl:
1196                         set_opt(sbi->s_mount_opt, POSIX_ACL);
1197                         break;
1198                 case Opt_noacl:
1199                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
1200                         break;
1201 #else
1202                 case Opt_acl:
1203                 case Opt_noacl:
1204                         printk(KERN_ERR "EXT4 (no)acl options "
1205                                "not supported\n");
1206                         break;
1207 #endif
1208                 case Opt_reservation:
1209                         set_opt(sbi->s_mount_opt, RESERVATION);
1210                         break;
1211                 case Opt_noreservation:
1212                         clear_opt(sbi->s_mount_opt, RESERVATION);
1213                         break;
1214                 case Opt_journal_update:
1215                         /* @@@ FIXME */
1216                         /* Eventually we will want to be able to create
1217                            a journal file here.  For now, only allow the
1218                            user to specify an existing inode to be the
1219                            journal file. */
1220                         if (is_remount) {
1221                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1222                                        "journal on remount\n");
1223                                 return 0;
1224                         }
1225                         set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1226                         break;
1227                 case Opt_journal_dev:
1228                         if (is_remount) {
1229                                 printk(KERN_ERR "EXT4-fs: cannot specify "
1230                                        "journal on remount\n");
1231                                 return 0;
1232                         }
1233                         if (match_int(&args[0], &option))
1234                                 return 0;
1235                         *journal_devnum = option;
1236                         break;
1237                 case Opt_journal_checksum:
1238                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1239                         break;
1240                 case Opt_journal_async_commit:
1241                         set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1242                         set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1243                         break;
1244                 case Opt_noload:
1245                         set_opt(sbi->s_mount_opt, NOLOAD);
1246                         break;
1247                 case Opt_commit:
1248                         if (match_int(&args[0], &option))
1249                                 return 0;
1250                         if (option < 0)
1251                                 return 0;
1252                         if (option == 0)
1253                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1254                         sbi->s_commit_interval = HZ * option;
1255                         break;
1256                 case Opt_max_batch_time:
1257                         if (match_int(&args[0], &option))
1258                                 return 0;
1259                         if (option < 0)
1260                                 return 0;
1261                         if (option == 0)
1262                                 option = EXT4_DEF_MAX_BATCH_TIME;
1263                         sbi->s_max_batch_time = option;
1264                         break;
1265                 case Opt_min_batch_time:
1266                         if (match_int(&args[0], &option))
1267                                 return 0;
1268                         if (option < 0)
1269                                 return 0;
1270                         sbi->s_min_batch_time = option;
1271                         break;
1272                 case Opt_data_journal:
1273                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1274                         goto datacheck;
1275                 case Opt_data_ordered:
1276                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1277                         goto datacheck;
1278                 case Opt_data_writeback:
1279                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1280                 datacheck:
1281                         if (is_remount) {
1282                                 if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1283                                                 != data_opt) {
1284                                         printk(KERN_ERR
1285                                                 "EXT4-fs: cannot change data "
1286                                                 "mode on remount\n");
1287                                         return 0;
1288                                 }
1289                         } else {
1290                                 sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1291                                 sbi->s_mount_opt |= data_opt;
1292                         }
1293                         break;
1294                 case Opt_data_err_abort:
1295                         set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1296                         break;
1297                 case Opt_data_err_ignore:
1298                         clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1299                         break;
1300 #ifdef CONFIG_QUOTA
1301                 case Opt_usrjquota:
1302                         qtype = USRQUOTA;
1303                         goto set_qf_name;
1304                 case Opt_grpjquota:
1305                         qtype = GRPQUOTA;
1306 set_qf_name:
1307                         if (sb_any_quota_loaded(sb) &&
1308                             !sbi->s_qf_names[qtype]) {
1309                                 printk(KERN_ERR
1310                                        "EXT4-fs: Cannot change journaled "
1311                                        "quota options when quota turned on.\n");
1312                                 return 0;
1313                         }
1314                         qname = match_strdup(&args[0]);
1315                         if (!qname) {
1316                                 printk(KERN_ERR
1317                                         "EXT4-fs: not enough memory for "
1318                                         "storing quotafile name.\n");
1319                                 return 0;
1320                         }
1321                         if (sbi->s_qf_names[qtype] &&
1322                             strcmp(sbi->s_qf_names[qtype], qname)) {
1323                                 printk(KERN_ERR
1324                                         "EXT4-fs: %s quota file already "
1325                                         "specified.\n", QTYPE2NAME(qtype));
1326                                 kfree(qname);
1327                                 return 0;
1328                         }
1329                         sbi->s_qf_names[qtype] = qname;
1330                         if (strchr(sbi->s_qf_names[qtype], '/')) {
1331                                 printk(KERN_ERR
1332                                         "EXT4-fs: quotafile must be on "
1333                                         "filesystem root.\n");
1334                                 kfree(sbi->s_qf_names[qtype]);
1335                                 sbi->s_qf_names[qtype] = NULL;
1336                                 return 0;
1337                         }
1338                         set_opt(sbi->s_mount_opt, QUOTA);
1339                         break;
1340                 case Opt_offusrjquota:
1341                         qtype = USRQUOTA;
1342                         goto clear_qf_name;
1343                 case Opt_offgrpjquota:
1344                         qtype = GRPQUOTA;
1345 clear_qf_name:
1346                         if (sb_any_quota_loaded(sb) &&
1347                             sbi->s_qf_names[qtype]) {
1348                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1349                                         "journaled quota options when "
1350                                         "quota turned on.\n");
1351                                 return 0;
1352                         }
1353                         /*
1354                          * The space will be released later when all options
1355                          * are confirmed to be correct
1356                          */
1357                         sbi->s_qf_names[qtype] = NULL;
1358                         break;
1359                 case Opt_jqfmt_vfsold:
1360                         qfmt = QFMT_VFS_OLD;
1361                         goto set_qf_format;
1362                 case Opt_jqfmt_vfsv0:
1363                         qfmt = QFMT_VFS_V0;
1364 set_qf_format:
1365                         if (sb_any_quota_loaded(sb) &&
1366                             sbi->s_jquota_fmt != qfmt) {
1367                                 printk(KERN_ERR "EXT4-fs: Cannot change "
1368                                         "journaled quota options when "
1369                                         "quota turned on.\n");
1370                                 return 0;
1371                         }
1372                         sbi->s_jquota_fmt = qfmt;
1373                         break;
1374                 case Opt_quota:
1375                 case Opt_usrquota:
1376                         set_opt(sbi->s_mount_opt, QUOTA);
1377                         set_opt(sbi->s_mount_opt, USRQUOTA);
1378                         break;
1379                 case Opt_grpquota:
1380                         set_opt(sbi->s_mount_opt, QUOTA);
1381                         set_opt(sbi->s_mount_opt, GRPQUOTA);
1382                         break;
1383                 case Opt_noquota:
1384                         if (sb_any_quota_loaded(sb)) {
1385                                 printk(KERN_ERR "EXT4-fs: Cannot change quota "
1386                                         "options when quota turned on.\n");
1387                                 return 0;
1388                         }
1389                         clear_opt(sbi->s_mount_opt, QUOTA);
1390                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1391                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1392                         break;
1393 #else
1394                 case Opt_quota:
1395                 case Opt_usrquota:
1396                 case Opt_grpquota:
1397                         printk(KERN_ERR
1398                                 "EXT4-fs: quota options not supported.\n");
1399                         break;
1400                 case Opt_usrjquota:
1401                 case Opt_grpjquota:
1402                 case Opt_offusrjquota:
1403                 case Opt_offgrpjquota:
1404                 case Opt_jqfmt_vfsold:
1405                 case Opt_jqfmt_vfsv0:
1406                         printk(KERN_ERR
1407                                 "EXT4-fs: journaled quota options not "
1408                                 "supported.\n");
1409                         break;
1410                 case Opt_noquota:
1411                         break;
1412 #endif
1413                 case Opt_abort:
1414                         set_opt(sbi->s_mount_opt, ABORT);
1415                         break;
1416                 case Opt_barrier:
1417                         if (match_int(&args[0], &option))
1418                                 return 0;
1419                         if (option)
1420                                 set_opt(sbi->s_mount_opt, BARRIER);
1421                         else
1422                                 clear_opt(sbi->s_mount_opt, BARRIER);
1423                         break;
1424                 case Opt_ignore:
1425                         break;
1426                 case Opt_resize:
1427                         if (!is_remount) {
1428                                 printk("EXT4-fs: resize option only available "
1429                                         "for remount\n");
1430                                 return 0;
1431                         }
1432                         if (match_int(&args[0], &option) != 0)
1433                                 return 0;
1434                         *n_blocks_count = option;
1435                         break;
1436                 case Opt_nobh:
1437                         set_opt(sbi->s_mount_opt, NOBH);
1438                         break;
1439                 case Opt_bh:
1440                         clear_opt(sbi->s_mount_opt, NOBH);
1441                         break;
1442                 case Opt_i_version:
1443                         set_opt(sbi->s_mount_opt, I_VERSION);
1444                         sb->s_flags |= MS_I_VERSION;
1445                         break;
1446                 case Opt_nodelalloc:
1447                         clear_opt(sbi->s_mount_opt, DELALLOC);
1448                         break;
1449                 case Opt_stripe:
1450                         if (match_int(&args[0], &option))
1451                                 return 0;
1452                         if (option < 0)
1453                                 return 0;
1454                         sbi->s_stripe = option;
1455                         break;
1456                 case Opt_delalloc:
1457                         set_opt(sbi->s_mount_opt, DELALLOC);
1458                         break;
1459                 case Opt_inode_readahead_blks:
1460                         if (match_int(&args[0], &option))
1461                                 return 0;
1462                         if (option < 0 || option > (1 << 30))
1463                                 return 0;
1464                         sbi->s_inode_readahead_blks = option;
1465                         break;
1466                 case Opt_journal_ioprio:
1467                         if (match_int(&args[0], &option))
1468                                 return 0;
1469                         if (option < 0 || option > 7)
1470                                 break;
1471                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1472                                                             option);
1473                         break;
1474                 default:
1475                         printk(KERN_ERR
1476                                "EXT4-fs: Unrecognized mount option \"%s\" "
1477                                "or missing value\n", p);
1478                         return 0;
1479                 }
1480         }
1481 #ifdef CONFIG_QUOTA
1482         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1483                 if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1484                      sbi->s_qf_names[USRQUOTA])
1485                         clear_opt(sbi->s_mount_opt, USRQUOTA);
1486
1487                 if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1488                      sbi->s_qf_names[GRPQUOTA])
1489                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
1490
1491                 if ((sbi->s_qf_names[USRQUOTA] &&
1492                                 (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1493                     (sbi->s_qf_names[GRPQUOTA] &&
1494                                 (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1495                         printk(KERN_ERR "EXT4-fs: old and new quota "
1496                                         "format mixing.\n");
1497                         return 0;
1498                 }
1499
1500                 if (!sbi->s_jquota_fmt) {
1501                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1502                                         "not specified.\n");
1503                         return 0;
1504                 }
1505         } else {
1506                 if (sbi->s_jquota_fmt) {
1507                         printk(KERN_ERR "EXT4-fs: journaled quota format "
1508                                         "specified with no journaling "
1509                                         "enabled.\n");
1510                         return 0;
1511                 }
1512         }
1513 #endif
1514         return 1;
1515 }
1516
1517 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1518                             int read_only)
1519 {
1520         struct ext4_sb_info *sbi = EXT4_SB(sb);
1521         int res = 0;
1522
1523         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1524                 printk(KERN_ERR "EXT4-fs warning: revision level too high, "
1525                        "forcing read-only mode\n");
1526                 res = MS_RDONLY;
1527         }
1528         if (read_only)
1529                 return res;
1530         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1531                 printk(KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1532                        "running e2fsck is recommended\n");
1533         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1534                 printk(KERN_WARNING
1535                        "EXT4-fs warning: mounting fs with errors, "
1536                        "running e2fsck is recommended\n");
1537         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1538                  le16_to_cpu(es->s_mnt_count) >=
1539                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1540                 printk(KERN_WARNING
1541                        "EXT4-fs warning: maximal mount count reached, "
1542                        "running e2fsck is recommended\n");
1543         else if (le32_to_cpu(es->s_checkinterval) &&
1544                 (le32_to_cpu(es->s_lastcheck) +
1545                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1546                 printk(KERN_WARNING
1547                        "EXT4-fs warning: checktime reached, "
1548                        "running e2fsck is recommended\n");
1549         if (!sbi->s_journal) 
1550                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1551         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1552                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1553         le16_add_cpu(&es->s_mnt_count, 1);
1554         es->s_mtime = cpu_to_le32(get_seconds());
1555         ext4_update_dynamic_rev(sb);
1556         if (sbi->s_journal)
1557                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1558
1559         ext4_commit_super(sb, es, 1);
1560         if (test_opt(sb, DEBUG))
1561                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1562                                 "bpg=%lu, ipg=%lu, mo=%04lx]\n",
1563                         sb->s_blocksize,
1564                         sbi->s_groups_count,
1565                         EXT4_BLOCKS_PER_GROUP(sb),
1566                         EXT4_INODES_PER_GROUP(sb),
1567                         sbi->s_mount_opt);
1568
1569         if (EXT4_SB(sb)->s_journal) {
1570                 printk(KERN_INFO "EXT4 FS on %s, %s journal on %s\n",
1571                        sb->s_id, EXT4_SB(sb)->s_journal->j_inode ? "internal" :
1572                        "external", EXT4_SB(sb)->s_journal->j_devname);
1573         } else {
1574                 printk(KERN_INFO "EXT4 FS on %s, no journal\n", sb->s_id);
1575         }
1576         return res;
1577 }
1578
1579 static int ext4_fill_flex_info(struct super_block *sb)
1580 {
1581         struct ext4_sb_info *sbi = EXT4_SB(sb);
1582         struct ext4_group_desc *gdp = NULL;
1583         struct buffer_head *bh;
1584         ext4_group_t flex_group_count;
1585         ext4_group_t flex_group;
1586         int groups_per_flex = 0;
1587         int i;
1588
1589         if (!sbi->s_es->s_log_groups_per_flex) {
1590                 sbi->s_log_groups_per_flex = 0;
1591                 return 1;
1592         }
1593
1594         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1595         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1596
1597         /* We allocate both existing and potentially added groups */
1598         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1599                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1600                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1601         sbi->s_flex_groups = kzalloc(flex_group_count *
1602                                      sizeof(struct flex_groups), GFP_KERNEL);
1603         if (sbi->s_flex_groups == NULL) {
1604                 printk(KERN_ERR "EXT4-fs: not enough memory for "
1605                                 "%u flex groups\n", flex_group_count);
1606                 goto failed;
1607         }
1608
1609         for (i = 0; i < sbi->s_groups_count; i++) {
1610                 gdp = ext4_get_group_desc(sb, i, &bh);
1611
1612                 flex_group = ext4_flex_group(sbi, i);
1613                 sbi->s_flex_groups[flex_group].free_inodes +=
1614                         ext4_free_inodes_count(sb, gdp);
1615                 sbi->s_flex_groups[flex_group].free_blocks +=
1616                         ext4_free_blks_count(sb, gdp);
1617         }
1618
1619         return 1;
1620 failed:
1621         return 0;
1622 }
1623
1624 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1625                             struct ext4_group_desc *gdp)
1626 {
1627         __u16 crc = 0;
1628
1629         if (sbi->s_es->s_feature_ro_compat &
1630             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1631                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1632                 __le32 le_group = cpu_to_le32(block_group);
1633
1634                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1635                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1636                 crc = crc16(crc, (__u8 *)gdp, offset);
1637                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1638                 /* for checksum of struct ext4_group_desc do the rest...*/
1639                 if ((sbi->s_es->s_feature_incompat &
1640                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1641                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1642                         crc = crc16(crc, (__u8 *)gdp + offset,
1643                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1644                                         offset);
1645         }
1646
1647         return cpu_to_le16(crc);
1648 }
1649
1650 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1651                                 struct ext4_group_desc *gdp)
1652 {
1653         if ((sbi->s_es->s_feature_ro_compat &
1654              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1655             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1656                 return 0;
1657
1658         return 1;
1659 }
1660
1661 /* Called at mount-time, super-block is locked */
1662 static int ext4_check_descriptors(struct super_block *sb)
1663 {
1664         struct ext4_sb_info *sbi = EXT4_SB(sb);
1665         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1666         ext4_fsblk_t last_block;
1667         ext4_fsblk_t block_bitmap;
1668         ext4_fsblk_t inode_bitmap;
1669         ext4_fsblk_t inode_table;
1670         int flexbg_flag = 0;
1671         ext4_group_t i;
1672
1673         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1674                 flexbg_flag = 1;
1675
1676         ext4_debug("Checking group descriptors");
1677
1678         for (i = 0; i < sbi->s_groups_count; i++) {
1679                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1680
1681                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
1682                         last_block = ext4_blocks_count(sbi->s_es) - 1;
1683                 else
1684                         last_block = first_block +
1685                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
1686
1687                 block_bitmap = ext4_block_bitmap(sb, gdp);
1688                 if (block_bitmap < first_block || block_bitmap > last_block) {
1689                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1690                                "Block bitmap for group %u not in group "
1691                                "(block %llu)!\n", i, block_bitmap);
1692                         return 0;
1693                 }
1694                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
1695                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
1696                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1697                                "Inode bitmap for group %u not in group "
1698                                "(block %llu)!\n", i, inode_bitmap);
1699                         return 0;
1700                 }
1701                 inode_table = ext4_inode_table(sb, gdp);
1702                 if (inode_table < first_block ||
1703                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
1704                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1705                                "Inode table for group %u not in group "
1706                                "(block %llu)!\n", i, inode_table);
1707                         return 0;
1708                 }
1709                 spin_lock(sb_bgl_lock(sbi, i));
1710                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1711                         printk(KERN_ERR "EXT4-fs: ext4_check_descriptors: "
1712                                "Checksum for group %u failed (%u!=%u)\n",
1713                                i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1714                                gdp)), le16_to_cpu(gdp->bg_checksum));
1715                         if (!(sb->s_flags & MS_RDONLY)) {
1716                                 spin_unlock(sb_bgl_lock(sbi, i));
1717                                 return 0;
1718                         }
1719                 }
1720                 spin_unlock(sb_bgl_lock(sbi, i));
1721                 if (!flexbg_flag)
1722                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
1723         }
1724
1725         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1726         sbi->s_es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
1727         return 1;
1728 }
1729
1730 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1731  * the superblock) which were deleted from all directories, but held open by
1732  * a process at the time of a crash.  We walk the list and try to delete these
1733  * inodes at recovery time (only with a read-write filesystem).
1734  *
1735  * In order to keep the orphan inode chain consistent during traversal (in
1736  * case of crash during recovery), we link each inode into the superblock
1737  * orphan list_head and handle it the same way as an inode deletion during
1738  * normal operation (which journals the operations for us).
1739  *
1740  * We only do an iget() and an iput() on each inode, which is very safe if we
1741  * accidentally point at an in-use or already deleted inode.  The worst that
1742  * can happen in this case is that we get a "bit already cleared" message from
1743  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1744  * e2fsck was run on this filesystem, and it must have already done the orphan
1745  * inode cleanup for us, so we can safely abort without any further action.
1746  */
1747 static void ext4_orphan_cleanup(struct super_block *sb,
1748                                 struct ext4_super_block *es)
1749 {
1750         unsigned int s_flags = sb->s_flags;
1751         int nr_orphans = 0, nr_truncates = 0;
1752 #ifdef CONFIG_QUOTA
1753         int i;
1754 #endif
1755         if (!es->s_last_orphan) {
1756                 jbd_debug(4, "no orphan inodes to clean up\n");
1757                 return;
1758         }
1759
1760         if (bdev_read_only(sb->s_bdev)) {
1761                 printk(KERN_ERR "EXT4-fs: write access "
1762                         "unavailable, skipping orphan cleanup.\n");
1763                 return;
1764         }
1765
1766         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1767                 if (es->s_last_orphan)
1768                         jbd_debug(1, "Errors on filesystem, "
1769                                   "clearing orphan list.\n");
1770                 es->s_last_orphan = 0;
1771                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1772                 return;
1773         }
1774
1775         if (s_flags & MS_RDONLY) {
1776                 printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1777                        sb->s_id);
1778                 sb->s_flags &= ~MS_RDONLY;
1779         }
1780 #ifdef CONFIG_QUOTA
1781         /* Needed for iput() to work correctly and not trash data */
1782         sb->s_flags |= MS_ACTIVE;
1783         /* Turn on quotas so that they are updated correctly */
1784         for (i = 0; i < MAXQUOTAS; i++) {
1785                 if (EXT4_SB(sb)->s_qf_names[i]) {
1786                         int ret = ext4_quota_on_mount(sb, i);
1787                         if (ret < 0)
1788                                 printk(KERN_ERR
1789                                         "EXT4-fs: Cannot turn on journaled "
1790                                         "quota: error %d\n", ret);
1791                 }
1792         }
1793 #endif
1794
1795         while (es->s_last_orphan) {
1796                 struct inode *inode;
1797
1798                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1799                 if (IS_ERR(inode)) {
1800                         es->s_last_orphan = 0;
1801                         break;
1802                 }
1803
1804                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1805                 DQUOT_INIT(inode);
1806                 if (inode->i_nlink) {
1807                         printk(KERN_DEBUG
1808                                 "%s: truncating inode %lu to %lld bytes\n",
1809                                 __func__, inode->i_ino, inode->i_size);
1810                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
1811                                   inode->i_ino, inode->i_size);
1812                         ext4_truncate(inode);
1813                         nr_truncates++;
1814                 } else {
1815                         printk(KERN_DEBUG
1816                                 "%s: deleting unreferenced inode %lu\n",
1817                                 __func__, inode->i_ino);
1818                         jbd_debug(2, "deleting unreferenced inode %lu\n",
1819                                   inode->i_ino);
1820                         nr_orphans++;
1821                 }
1822                 iput(inode);  /* The delete magic happens here! */
1823         }
1824
1825 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
1826
1827         if (nr_orphans)
1828                 printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1829                        sb->s_id, PLURAL(nr_orphans));
1830         if (nr_truncates)
1831                 printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1832                        sb->s_id, PLURAL(nr_truncates));
1833 #ifdef CONFIG_QUOTA
1834         /* Turn quotas off */
1835         for (i = 0; i < MAXQUOTAS; i++) {
1836                 if (sb_dqopt(sb)->files[i])
1837                         vfs_quota_off(sb, i, 0);
1838         }
1839 #endif
1840         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1841 }
1842 /*
1843  * Maximal extent format file size.
1844  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1845  * extent format containers, within a sector_t, and within i_blocks
1846  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1847  * so that won't be a limiting factor.
1848  *
1849  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1850  */
1851 static loff_t ext4_max_size(int blkbits, int has_huge_files)
1852 {
1853         loff_t res;
1854         loff_t upper_limit = MAX_LFS_FILESIZE;
1855
1856         /* small i_blocks in vfs inode? */
1857         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1858                 /*
1859                  * CONFIG_LBD is not enabled implies the inode
1860                  * i_block represent total blocks in 512 bytes
1861                  * 32 == size of vfs inode i_blocks * 8
1862                  */
1863                 upper_limit = (1LL << 32) - 1;
1864
1865                 /* total blocks in file system block size */
1866                 upper_limit >>= (blkbits - 9);
1867                 upper_limit <<= blkbits;
1868         }
1869
1870         /* 32-bit extent-start container, ee_block */
1871         res = 1LL << 32;
1872         res <<= blkbits;
1873         res -= 1;
1874
1875         /* Sanity check against vm- & vfs- imposed limits */
1876         if (res > upper_limit)
1877                 res = upper_limit;
1878
1879         return res;
1880 }
1881
1882 /*
1883  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1884  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1885  * We need to be 1 filesystem block less than the 2^48 sector limit.
1886  */
1887 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
1888 {
1889         loff_t res = EXT4_NDIR_BLOCKS;
1890         int meta_blocks;
1891         loff_t upper_limit;
1892         /* This is calculated to be the largest file size for a
1893          * dense, bitmapped file such that the total number of
1894          * sectors in the file, including data and all indirect blocks,
1895          * does not exceed 2^48 -1
1896          * __u32 i_blocks_lo and _u16 i_blocks_high representing the
1897          * total number of  512 bytes blocks of the file
1898          */
1899
1900         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1901                 /*
1902                  * !has_huge_files or CONFIG_LBD is not enabled
1903                  * implies the inode i_block represent total blocks in
1904                  * 512 bytes 32 == size of vfs inode i_blocks * 8
1905                  */
1906                 upper_limit = (1LL << 32) - 1;
1907
1908                 /* total blocks in file system block size */
1909                 upper_limit >>= (bits - 9);
1910
1911         } else {
1912                 /*
1913                  * We use 48 bit ext4_inode i_blocks
1914                  * With EXT4_HUGE_FILE_FL set the i_blocks
1915                  * represent total number of blocks in
1916                  * file system block size
1917                  */
1918                 upper_limit = (1LL << 48) - 1;
1919
1920         }
1921
1922         /* indirect blocks */
1923         meta_blocks = 1;
1924         /* double indirect blocks */
1925         meta_blocks += 1 + (1LL << (bits-2));
1926         /* tripple indirect blocks */
1927         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
1928
1929         upper_limit -= meta_blocks;
1930         upper_limit <<= bits;
1931
1932         res += 1LL << (bits-2);
1933         res += 1LL << (2*(bits-2));
1934         res += 1LL << (3*(bits-2));
1935         res <<= bits;
1936         if (res > upper_limit)
1937                 res = upper_limit;
1938
1939         if (res > MAX_LFS_FILESIZE)
1940                 res = MAX_LFS_FILESIZE;
1941
1942         return res;
1943 }
1944
1945 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1946                                 ext4_fsblk_t logical_sb_block, int nr)
1947 {
1948         struct ext4_sb_info *sbi = EXT4_SB(sb);
1949         ext4_group_t bg, first_meta_bg;
1950         int has_super = 0;
1951
1952         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1953
1954         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1955             nr < first_meta_bg)
1956                 return logical_sb_block + nr + 1;
1957         bg = sbi->s_desc_per_block * nr;
1958         if (ext4_bg_has_super(sb, bg))
1959                 has_super = 1;
1960         return (has_super + ext4_group_first_block_no(sb, bg));
1961 }
1962
1963 /**
1964  * ext4_get_stripe_size: Get the stripe size.
1965  * @sbi: In memory super block info
1966  *
1967  * If we have specified it via mount option, then
1968  * use the mount option value. If the value specified at mount time is
1969  * greater than the blocks per group use the super block value.
1970  * If the super block value is greater than blocks per group return 0.
1971  * Allocator needs it be less than blocks per group.
1972  *
1973  */
1974 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
1975 {
1976         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
1977         unsigned long stripe_width =
1978                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
1979
1980         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
1981                 return sbi->s_stripe;
1982
1983         if (stripe_width <= sbi->s_blocks_per_group)
1984                 return stripe_width;
1985
1986         if (stride <= sbi->s_blocks_per_group)
1987                 return stride;
1988
1989         return 0;
1990 }
1991
1992 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
1993                                 __releases(kernel_lock)
1994                                 __acquires(kernel_lock)
1995
1996 {
1997         struct buffer_head *bh;
1998         struct ext4_super_block *es = NULL;
1999         struct ext4_sb_info *sbi;
2000         ext4_fsblk_t block;
2001         ext4_fsblk_t sb_block = get_sb_block(&data);
2002         ext4_fsblk_t logical_sb_block;
2003         unsigned long offset = 0;
2004         unsigned long journal_devnum = 0;
2005         unsigned long def_mount_opts;
2006         struct inode *root;
2007         char *cp;
2008         const char *descr;
2009         int ret = -EINVAL;
2010         int blocksize;
2011         unsigned int db_count;
2012         unsigned int i;
2013         int needs_recovery, has_huge_files;
2014         int features;
2015         __u64 blocks_count;
2016         int err;
2017         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2018
2019         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2020         if (!sbi)
2021                 return -ENOMEM;
2022         sb->s_fs_info = sbi;
2023         sbi->s_mount_opt = 0;
2024         sbi->s_resuid = EXT4_DEF_RESUID;
2025         sbi->s_resgid = EXT4_DEF_RESGID;
2026         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
2027         sbi->s_sb_block = sb_block;
2028
2029         unlock_kernel();
2030
2031         /* Cleanup superblock name */
2032         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
2033                 *cp = '!';
2034
2035         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
2036         if (!blocksize) {
2037                 printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
2038                 goto out_fail;
2039         }
2040
2041         /*
2042          * The ext4 superblock will not be buffer aligned for other than 1kB
2043          * block sizes.  We need to calculate the offset from buffer start.
2044          */
2045         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
2046                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2047                 offset = do_div(logical_sb_block, blocksize);
2048         } else {
2049                 logical_sb_block = sb_block;
2050         }
2051
2052         if (!(bh = sb_bread(sb, logical_sb_block))) {
2053                 printk(KERN_ERR "EXT4-fs: unable to read superblock\n");
2054                 goto out_fail;
2055         }
2056         /*
2057          * Note: s_es must be initialized as soon as possible because
2058          *       some ext4 macro-instructions depend on its value
2059          */
2060         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2061         sbi->s_es = es;
2062         sb->s_magic = le16_to_cpu(es->s_magic);
2063         if (sb->s_magic != EXT4_SUPER_MAGIC)
2064                 goto cantfind_ext4;
2065
2066         /* Set defaults before we parse the mount options */
2067         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
2068         if (def_mount_opts & EXT4_DEFM_DEBUG)
2069                 set_opt(sbi->s_mount_opt, DEBUG);
2070         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
2071                 set_opt(sbi->s_mount_opt, GRPID);
2072         if (def_mount_opts & EXT4_DEFM_UID16)
2073                 set_opt(sbi->s_mount_opt, NO_UID32);
2074 #ifdef CONFIG_EXT4_FS_XATTR
2075         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
2076                 set_opt(sbi->s_mount_opt, XATTR_USER);
2077 #endif
2078 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2079         if (def_mount_opts & EXT4_DEFM_ACL)
2080                 set_opt(sbi->s_mount_opt, POSIX_ACL);
2081 #endif
2082         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
2083                 sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
2084         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
2085                 sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
2086         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
2087                 sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
2088
2089         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
2090                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
2091         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
2092                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
2093         else
2094                 set_opt(sbi->s_mount_opt, ERRORS_RO);
2095
2096         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
2097         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
2098         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
2099         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
2100         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
2101
2102         set_opt(sbi->s_mount_opt, RESERVATION);
2103         set_opt(sbi->s_mount_opt, BARRIER);
2104
2105         /*
2106          * enable delayed allocation by default
2107          * Use -o nodelalloc to turn it off
2108          */
2109         set_opt(sbi->s_mount_opt, DELALLOC);
2110
2111
2112         if (!parse_options((char *) data, sb, &journal_devnum,
2113                            &journal_ioprio, NULL, 0))
2114                 goto failed_mount;
2115
2116         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2117                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2118
2119         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
2120             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
2121              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
2122              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
2123                 printk(KERN_WARNING
2124                        "EXT4-fs warning: feature flags set on rev 0 fs, "
2125                        "running e2fsck is recommended\n");
2126
2127         /*
2128          * Check feature flags regardless of the revision level, since we
2129          * previously didn't change the revision level when setting the flags,
2130          * so there is a chance incompat flags are set on a rev 0 filesystem.
2131          */
2132         features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
2133         if (features) {
2134                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
2135                        "unsupported optional features (%x).\n", sb->s_id,
2136                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2137                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2138                 goto failed_mount;
2139         }
2140         features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
2141         if (!(sb->s_flags & MS_RDONLY) && features) {
2142                 printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
2143                        "unsupported optional features (%x).\n", sb->s_id,
2144                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2145                         ~EXT4_FEATURE_RO_COMPAT_SUPP));
2146                 goto failed_mount;
2147         }
2148         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2149                                     EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
2150         if (has_huge_files) {
2151                 /*
2152                  * Large file size enabled file system can only be
2153                  * mount if kernel is build with CONFIG_LBD
2154                  */
2155                 if (sizeof(root->i_blocks) < sizeof(u64) &&
2156                                 !(sb->s_flags & MS_RDONLY)) {
2157                         printk(KERN_ERR "EXT4-fs: %s: Filesystem with huge "
2158                                         "files cannot be mounted read-write "
2159                                         "without CONFIG_LBD.\n", sb->s_id);
2160                         goto failed_mount;
2161                 }
2162         }
2163         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2164
2165         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2166             blocksize > EXT4_MAX_BLOCK_SIZE) {
2167                 printk(KERN_ERR
2168                        "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
2169                        blocksize, sb->s_id);
2170                 goto failed_mount;
2171         }
2172
2173         if (sb->s_blocksize != blocksize) {
2174
2175                 /* Validate the filesystem blocksize */
2176                 if (!sb_set_blocksize(sb, blocksize)) {
2177                         printk(KERN_ERR "EXT4-fs: bad block size %d.\n",
2178                                         blocksize);
2179                         goto failed_mount;
2180                 }
2181
2182                 brelse(bh);
2183                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2184                 offset = do_div(logical_sb_block, blocksize);
2185                 bh = sb_bread(sb, logical_sb_block);
2186                 if (!bh) {
2187                         printk(KERN_ERR
2188                                "EXT4-fs: Can't read superblock on 2nd try.\n");
2189                         goto failed_mount;
2190                 }
2191                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2192                 sbi->s_es = es;
2193                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2194                         printk(KERN_ERR
2195                                "EXT4-fs: Magic mismatch, very weird !\n");
2196                         goto failed_mount;
2197                 }
2198         }
2199
2200         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
2201                                                       has_huge_files);
2202         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
2203
2204         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2205                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2206                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2207         } else {
2208                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2209                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2210                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2211                     (!is_power_of_2(sbi->s_inode_size)) ||
2212                     (sbi->s_inode_size > blocksize)) {
2213                         printk(KERN_ERR
2214                                "EXT4-fs: unsupported inode size: %d\n",
2215                                sbi->s_inode_size);
2216                         goto failed_mount;
2217                 }
2218                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2219                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2220         }
2221         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2222         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2223                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2224                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2225                     !is_power_of_2(sbi->s_desc_size)) {
2226                         printk(KERN_ERR
2227                                "EXT4-fs: unsupported descriptor size %lu\n",
2228                                sbi->s_desc_size);
2229                         goto failed_mount;
2230                 }
2231         } else
2232                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2233         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2234         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2235         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2236                 goto cantfind_ext4;
2237         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2238         if (sbi->s_inodes_per_block == 0)
2239                 goto cantfind_ext4;
2240         sbi->s_itb_per_group = sbi->s_inodes_per_group /
2241                                         sbi->s_inodes_per_block;
2242         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2243         sbi->s_sbh = bh;
2244         sbi->s_mount_state = le16_to_cpu(es->s_state);
2245         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2246         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2247         for (i = 0; i < 4; i++)
2248                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2249         sbi->s_def_hash_version = es->s_def_hash_version;
2250         i = le32_to_cpu(es->s_flags);
2251         if (i & EXT2_FLAGS_UNSIGNED_HASH)
2252                 sbi->s_hash_unsigned = 3;
2253         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
2254 #ifdef __CHAR_UNSIGNED__
2255                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
2256                 sbi->s_hash_unsigned = 3;
2257 #else
2258                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
2259 #endif
2260                 sb->s_dirt = 1;
2261         }
2262
2263         if (sbi->s_blocks_per_group > blocksize * 8) {
2264                 printk(KERN_ERR
2265                        "EXT4-fs: #blocks per group too big: %lu\n",
2266                        sbi->s_blocks_per_group);
2267                 goto failed_mount;
2268         }
2269         if (sbi->s_inodes_per_group > blocksize * 8) {
2270                 printk(KERN_ERR
2271                        "EXT4-fs: #inodes per group too big: %lu\n",
2272                        sbi->s_inodes_per_group);
2273                 goto failed_mount;
2274         }
2275
2276         if (ext4_blocks_count(es) >
2277                     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2278                 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
2279                         " too large to mount safely\n", sb->s_id);
2280                 if (sizeof(sector_t) < 8)
2281                         printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
2282                                         "enabled\n");
2283                 goto failed_mount;
2284         }
2285
2286         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2287                 goto cantfind_ext4;
2288
2289         /*
2290          * It makes no sense for the first data block to be beyond the end
2291          * of the filesystem.
2292          */
2293         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
2294                 printk(KERN_WARNING "EXT4-fs: bad geometry: first data"
2295                        "block %u is beyond end of filesystem (%llu)\n",
2296                        le32_to_cpu(es->s_first_data_block),
2297                        ext4_blocks_count(es));
2298                 goto failed_mount;
2299         }
2300         blocks_count = (ext4_blocks_count(es) -
2301                         le32_to_cpu(es->s_first_data_block) +
2302                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
2303         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2304         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
2305                 printk(KERN_WARNING "EXT4-fs: groups count too large: %u "
2306                        "(block count %llu, first data block %u, "
2307                        "blocks per group %lu)\n", sbi->s_groups_count,
2308                        ext4_blocks_count(es),
2309                        le32_to_cpu(es->s_first_data_block),
2310                        EXT4_BLOCKS_PER_GROUP(sb));
2311                 goto failed_mount;
2312         }
2313         sbi->s_groups_count = blocks_count;
2314         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2315                    EXT4_DESC_PER_BLOCK(sb);
2316         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2317                                     GFP_KERNEL);
2318         if (sbi->s_group_desc == NULL) {
2319                 printk(KERN_ERR "EXT4-fs: not enough memory\n");
2320                 goto failed_mount;
2321         }
2322
2323 #ifdef CONFIG_PROC_FS
2324         if (ext4_proc_root)
2325                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
2326
2327         if (sbi->s_proc)
2328                 proc_create_data("inode_readahead_blks", 0644, sbi->s_proc,
2329                                  &ext4_ui_proc_fops,
2330                                  &sbi->s_inode_readahead_blks);
2331 #endif
2332
2333         bgl_lock_init(&sbi->s_blockgroup_lock);
2334
2335         for (i = 0; i < db_count; i++) {
2336                 block = descriptor_loc(sb, logical_sb_block, i);
2337                 sbi->s_group_desc[i] = sb_bread(sb, block);
2338                 if (!sbi->s_group_desc[i]) {
2339                         printk(KERN_ERR "EXT4-fs: "
2340                                "can't read group descriptor %d\n", i);
2341                         db_count = i;
2342                         goto failed_mount2;
2343                 }
2344         }
2345         if (!ext4_check_descriptors(sb)) {
2346                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
2347                 goto failed_mount2;
2348         }
2349         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2350                 if (!ext4_fill_flex_info(sb)) {
2351                         printk(KERN_ERR
2352                                "EXT4-fs: unable to initialize "
2353                                "flex_bg meta info!\n");
2354                         goto failed_mount2;
2355                 }
2356
2357         sbi->s_gdb_count = db_count;
2358         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2359         spin_lock_init(&sbi->s_next_gen_lock);
2360
2361         err = percpu_counter_init(&sbi->s_freeblocks_counter,
2362                         ext4_count_free_blocks(sb));
2363         if (!err) {
2364                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
2365                                 ext4_count_free_inodes(sb));
2366         }
2367         if (!err) {
2368                 err = percpu_counter_init(&sbi->s_dirs_counter,
2369                                 ext4_count_dirs(sb));
2370         }
2371         if (!err) {
2372                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
2373         }
2374         if (err) {
2375                 printk(KERN_ERR "EXT4-fs: insufficient memory\n");
2376                 goto failed_mount3;
2377         }
2378
2379         sbi->s_stripe = ext4_get_stripe_size(sbi);
2380
2381         /*
2382          * set up enough so that it can read an inode
2383          */
2384         sb->s_op = &ext4_sops;
2385         sb->s_export_op = &ext4_export_ops;
2386         sb->s_xattr = ext4_xattr_handlers;
2387 #ifdef CONFIG_QUOTA
2388         sb->s_qcop = &ext4_qctl_operations;
2389         sb->dq_op = &ext4_quota_operations;
2390 #endif
2391         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2392
2393         sb->s_root = NULL;
2394
2395         needs_recovery = (es->s_last_orphan != 0 ||
2396                           EXT4_HAS_INCOMPAT_FEATURE(sb,
2397                                     EXT4_FEATURE_INCOMPAT_RECOVER));
2398
2399         /*
2400          * The first inode we look at is the journal inode.  Don't try
2401          * root first: it may be modified in the journal!
2402          */
2403         if (!test_opt(sb, NOLOAD) &&
2404             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2405                 if (ext4_load_journal(sb, es, journal_devnum))
2406                         goto failed_mount3;
2407                 if (!(sb->s_flags & MS_RDONLY) &&
2408                     EXT4_SB(sb)->s_journal->j_failed_commit) {
2409                         printk(KERN_CRIT "EXT4-fs error (device %s): "
2410                                "ext4_fill_super: Journal transaction "
2411                                "%u is corrupt\n", sb->s_id,
2412                                EXT4_SB(sb)->s_journal->j_failed_commit);
2413                         if (test_opt(sb, ERRORS_RO)) {
2414                                 printk(KERN_CRIT
2415                                        "Mounting filesystem read-only\n");
2416                                 sb->s_flags |= MS_RDONLY;
2417                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2418                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2419                         }
2420                         if (test_opt(sb, ERRORS_PANIC)) {
2421                                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2422                                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2423                                 ext4_commit_super(sb, es, 1);
2424                                 goto failed_mount4;
2425                         }
2426                 }
2427         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
2428               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2429                 printk(KERN_ERR "EXT4-fs: required journal recovery "
2430                        "suppressed and not mounted read-only\n");
2431                 goto failed_mount4;
2432         } else {
2433                 clear_opt(sbi->s_mount_opt, DATA_FLAGS);
2434                 set_opt(sbi->s_mount_opt, WRITEBACK_DATA);
2435                 sbi->s_journal = NULL;
2436                 needs_recovery = 0;
2437                 goto no_journal;
2438         }
2439
2440         if (ext4_blocks_count(es) > 0xffffffffULL &&
2441             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2442                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
2443                 printk(KERN_ERR "EXT4-fs: Failed to set 64-bit journal feature\n");
2444                 goto failed_mount4;
2445         }
2446
2447         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2448                 jbd2_journal_set_features(sbi->s_journal,
2449                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2450                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2451         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2452                 jbd2_journal_set_features(sbi->s_journal,
2453                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2454                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2455                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2456         } else {
2457                 jbd2_journal_clear_features(sbi->s_journal,
2458                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2459                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2460         }
2461
2462         /* We have now updated the journal if required, so we can
2463          * validate the data journaling mode. */
2464         switch (test_opt(sb, DATA_FLAGS)) {
2465         case 0:
2466                 /* No mode set, assume a default based on the journal
2467                  * capabilities: ORDERED_DATA if the journal can
2468                  * cope, else JOURNAL_DATA
2469                  */
2470                 if (jbd2_journal_check_available_features
2471                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2472                         set_opt(sbi->s_mount_opt, ORDERED_DATA);
2473                 else
2474                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2475                 break;
2476
2477         case EXT4_MOUNT_ORDERED_DATA:
2478         case EXT4_MOUNT_WRITEBACK_DATA:
2479                 if (!jbd2_journal_check_available_features
2480                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2481                         printk(KERN_ERR "EXT4-fs: Journal does not support "
2482                                "requested data journaling mode\n");
2483                         goto failed_mount4;
2484                 }
2485         default:
2486                 break;
2487         }
2488         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
2489
2490 no_journal:
2491
2492         if (test_opt(sb, NOBH)) {
2493                 if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2494                         printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
2495                                 "its supported only with writeback mode\n");
2496                         clear_opt(sbi->s_mount_opt, NOBH);
2497                 }
2498         }
2499         /*
2500          * The jbd2_journal_load will have done any necessary log recovery,
2501          * so we can safely mount the rest of the filesystem now.
2502          */
2503
2504         root = ext4_iget(sb, EXT4_ROOT_INO);
2505         if (IS_ERR(root)) {
2506                 printk(KERN_ERR "EXT4-fs: get root inode failed\n");
2507                 ret = PTR_ERR(root);
2508                 goto failed_mount4;
2509         }
2510         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2511                 iput(root);
2512                 printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
2513                 goto failed_mount4;
2514         }
2515         sb->s_root = d_alloc_root(root);
2516         if (!sb->s_root) {
2517                 printk(KERN_ERR "EXT4-fs: get root dentry failed\n");
2518                 iput(root);
2519                 ret = -ENOMEM;
2520                 goto failed_mount4;
2521         }
2522
2523         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
2524
2525         /* determine the minimum size of new large inodes, if present */
2526         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2527                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2528                                                      EXT4_GOOD_OLD_INODE_SIZE;
2529                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2530                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2531                         if (sbi->s_want_extra_isize <
2532                             le16_to_cpu(es->s_want_extra_isize))
2533                                 sbi->s_want_extra_isize =
2534                                         le16_to_cpu(es->s_want_extra_isize);
2535                         if (sbi->s_want_extra_isize <
2536                             le16_to_cpu(es->s_min_extra_isize))
2537                                 sbi->s_want_extra_isize =
2538                                         le16_to_cpu(es->s_min_extra_isize);
2539                 }
2540         }
2541         /* Check if enough inode space is available */
2542         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2543                                                         sbi->s_inode_size) {
2544                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2545                                                        EXT4_GOOD_OLD_INODE_SIZE;
2546                 printk(KERN_INFO "EXT4-fs: required extra inode space not"
2547                         "available.\n");
2548         }
2549
2550         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
2551                 printk(KERN_WARNING "EXT4-fs: Ignoring delalloc option - "
2552                                 "requested data journaling mode\n");
2553                 clear_opt(sbi->s_mount_opt, DELALLOC);
2554         } else if (test_opt(sb, DELALLOC))
2555                 printk(KERN_INFO "EXT4-fs: delayed allocation enabled\n");
2556
2557         ext4_ext_init(sb);
2558         err = ext4_mb_init(sb, needs_recovery);
2559         if (err) {
2560                 printk(KERN_ERR "EXT4-fs: failed to initalize mballoc (%d)\n",
2561                        err);
2562                 goto failed_mount4;
2563         }
2564
2565         /*
2566          * akpm: core read_super() calls in here with the superblock locked.
2567          * That deadlocks, because orphan cleanup needs to lock the superblock
2568          * in numerous places.  Here we just pop the lock - it's relatively
2569          * harmless, because we are now ready to accept write_super() requests,
2570          * and aviro says that's the only reason for hanging onto the
2571          * superblock lock.
2572          */
2573         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2574         ext4_orphan_cleanup(sb, es);
2575         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2576         if (needs_recovery) {
2577                 printk(KERN_INFO "EXT4-fs: recovery complete.\n");
2578                 ext4_mark_recovery_complete(sb, es);
2579         }
2580         if (EXT4_SB(sb)->s_journal) {
2581                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2582                         descr = " journalled data mode";
2583                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2584                         descr = " ordered data mode";
2585                 else
2586                         descr = " writeback data mode";
2587         } else
2588                 descr = "out journal";
2589
2590         printk(KERN_INFO "EXT4-fs: mounted filesystem %s with%s\n",
2591                sb->s_id, descr);
2592
2593         lock_kernel();
2594         return 0;
2595
2596 cantfind_ext4:
2597         if (!silent)
2598                 printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
2599                        sb->s_id);
2600         goto failed_mount;
2601
2602 failed_mount4:
2603         printk(KERN_ERR "EXT4-fs (device %s): mount failed\n", sb->s_id);
2604         if (sbi->s_journal) {
2605                 jbd2_journal_destroy(sbi->s_journal);
2606                 sbi->s_journal = NULL;
2607         }
2608 failed_mount3:
2609         percpu_counter_destroy(&sbi->s_freeblocks_counter);
2610         percpu_counter_destroy(&sbi->s_freeinodes_counter);
2611         percpu_counter_destroy(&sbi->s_dirs_counter);
2612         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
2613 failed_mount2:
2614         for (i = 0; i < db_count; i++)
2615                 brelse(sbi->s_group_desc[i]);
2616         kfree(sbi->s_group_desc);
2617 failed_mount:
2618         if (sbi->s_proc) {
2619                 remove_proc_entry("inode_readahead_blks", sbi->s_proc);
2620                 remove_proc_entry(sb->s_id, ext4_proc_root);
2621         }
2622 #ifdef CONFIG_QUOTA
2623         for (i = 0; i < MAXQUOTAS; i++)
2624                 kfree(sbi->s_qf_names[i]);
2625 #endif
2626         ext4_blkdev_remove(sbi);
2627         brelse(bh);
2628 out_fail:
2629         sb->s_fs_info = NULL;
2630         kfree(sbi);
2631         lock_kernel();
2632         return ret;
2633 }
2634
2635 /*
2636  * Setup any per-fs journal parameters now.  We'll do this both on
2637  * initial mount, once the journal has been initialised but before we've
2638  * done any recovery; and again on any subsequent remount.
2639  */
2640 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2641 {
2642         struct ext4_sb_info *sbi = EXT4_SB(sb);
2643
2644         journal->j_commit_interval = sbi->s_commit_interval;
2645         journal->j_min_batch_time = sbi->s_min_batch_time;
2646         journal->j_max_batch_time = sbi->s_max_batch_time;
2647
2648         spin_lock(&journal->j_state_lock);
2649         if (test_opt(sb, BARRIER))
2650                 journal->j_flags |= JBD2_BARRIER;
2651         else
2652                 journal->j_flags &= ~JBD2_BARRIER;
2653         if (test_opt(sb, DATA_ERR_ABORT))
2654                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
2655         else
2656                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
2657         spin_unlock(&journal->j_state_lock);
2658 }
2659
2660 static journal_t *ext4_get_journal(struct super_block *sb,
2661                                    unsigned int journal_inum)
2662 {
2663         struct inode *journal_inode;
2664         journal_t *journal;
2665
2666         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2667
2668         /* First, test for the existence of a valid inode on disk.  Bad
2669          * things happen if we iget() an unused inode, as the subsequent
2670          * iput() will try to delete it. */
2671
2672         journal_inode = ext4_iget(sb, journal_inum);
2673         if (IS_ERR(journal_inode)) {
2674                 printk(KERN_ERR "EXT4-fs: no journal found.\n");
2675                 return NULL;
2676         }
2677         if (!journal_inode->i_nlink) {
2678                 make_bad_inode(journal_inode);
2679                 iput(journal_inode);
2680                 printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
2681                 return NULL;
2682         }
2683
2684         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
2685                   journal_inode, journal_inode->i_size);
2686         if (!S_ISREG(journal_inode->i_mode)) {
2687                 printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
2688                 iput(journal_inode);
2689                 return NULL;
2690         }
2691
2692         journal = jbd2_journal_init_inode(journal_inode);
2693         if (!journal) {
2694                 printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
2695                 iput(journal_inode);
2696                 return NULL;
2697         }
2698         journal->j_private = sb;
2699         ext4_init_journal_params(sb, journal);
2700         return journal;
2701 }
2702
2703 static journal_t *ext4_get_dev_journal(struct super_block *sb,
2704                                        dev_t j_dev)
2705 {
2706         struct buffer_head *bh;
2707         journal_t *journal;
2708         ext4_fsblk_t start;
2709         ext4_fsblk_t len;
2710         int hblock, blocksize;
2711         ext4_fsblk_t sb_block;
2712         unsigned long offset;
2713         struct ext4_super_block *es;
2714         struct block_device *bdev;
2715
2716         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2717
2718         bdev = ext4_blkdev_get(j_dev);
2719         if (bdev == NULL)
2720                 return NULL;
2721
2722         if (bd_claim(bdev, sb)) {
2723                 printk(KERN_ERR
2724                         "EXT4-fs: failed to claim external journal device.\n");
2725                 blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
2726                 return NULL;
2727         }
2728
2729         blocksize = sb->s_blocksize;
2730         hblock = bdev_hardsect_size(bdev);
2731         if (blocksize < hblock) {
2732                 printk(KERN_ERR
2733                         "EXT4-fs: blocksize too small for journal device.\n");
2734                 goto out_bdev;
2735         }
2736
2737         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2738         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2739         set_blocksize(bdev, blocksize);
2740         if (!(bh = __bread(bdev, sb_block, blocksize))) {
2741                 printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2742                        "external journal\n");
2743                 goto out_bdev;
2744         }
2745
2746         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2747         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2748             !(le32_to_cpu(es->s_feature_incompat) &
2749               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2750                 printk(KERN_ERR "EXT4-fs: external journal has "
2751                                         "bad superblock\n");
2752                 brelse(bh);
2753                 goto out_bdev;
2754         }
2755
2756         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2757                 printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2758                 brelse(bh);
2759                 goto out_bdev;
2760         }
2761
2762         len = ext4_blocks_count(es);
2763         start = sb_block + 1;
2764         brelse(bh);     /* we're done with the superblock */
2765
2766         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2767                                         start, len, blocksize);
2768         if (!journal) {
2769                 printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2770                 goto out_bdev;
2771         }
2772         journal->j_private = sb;
2773         ll_rw_block(READ, 1, &journal->j_sb_buffer);
2774         wait_on_buffer(journal->j_sb_buffer);
2775         if (!buffer_uptodate(journal->j_sb_buffer)) {
2776                 printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2777                 goto out_journal;
2778         }
2779         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2780                 printk(KERN_ERR "EXT4-fs: External journal has more than one "
2781                                         "user (unsupported) - %d\n",
2782                         be32_to_cpu(journal->j_superblock->s_nr_users));
2783                 goto out_journal;
2784         }
2785         EXT4_SB(sb)->journal_bdev = bdev;
2786         ext4_init_journal_params(sb, journal);
2787         return journal;
2788 out_journal:
2789         jbd2_journal_destroy(journal);
2790 out_bdev:
2791         ext4_blkdev_put(bdev);
2792         return NULL;
2793 }
2794
2795 static int ext4_load_journal(struct super_block *sb,
2796                              struct ext4_super_block *es,
2797                              unsigned long journal_devnum)
2798 {
2799         journal_t *journal;
2800         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2801         dev_t journal_dev;
2802         int err = 0;
2803         int really_read_only;
2804
2805         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2806
2807         if (journal_devnum &&
2808             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2809                 printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2810                         "numbers have changed\n");
2811                 journal_dev = new_decode_dev(journal_devnum);
2812         } else
2813                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2814
2815         really_read_only = bdev_read_only(sb->s_bdev);
2816
2817         /*
2818          * Are we loading a blank journal or performing recovery after a
2819          * crash?  For recovery, we need to check in advance whether we
2820          * can get read-write access to the device.
2821          */
2822
2823         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2824                 if (sb->s_flags & MS_RDONLY) {
2825                         printk(KERN_INFO "EXT4-fs: INFO: recovery "
2826                                         "required on readonly filesystem.\n");
2827                         if (really_read_only) {
2828                                 printk(KERN_ERR "EXT4-fs: write access "
2829                                         "unavailable, cannot proceed.\n");
2830                                 return -EROFS;
2831                         }
2832                         printk(KERN_INFO "EXT4-fs: write access will "
2833                                "be enabled during recovery.\n");
2834                 }
2835         }
2836
2837         if (journal_inum && journal_dev) {
2838                 printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2839                        "and inode journals!\n");
2840                 return -EINVAL;
2841         }
2842
2843         if (journal_inum) {
2844                 if (!(journal = ext4_get_journal(sb, journal_inum)))
2845                         return -EINVAL;
2846         } else {
2847                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2848                         return -EINVAL;
2849         }
2850
2851         if (journal->j_flags & JBD2_BARRIER)
2852                 printk(KERN_INFO "EXT4-fs: barriers enabled\n");
2853         else
2854                 printk(KERN_INFO "EXT4-fs: barriers disabled\n");
2855
2856         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2857                 err = jbd2_journal_update_format(journal);
2858                 if (err)  {
2859                         printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2860                         jbd2_journal_destroy(journal);
2861                         return err;
2862                 }
2863         }
2864
2865         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2866                 err = jbd2_journal_wipe(journal, !really_read_only);
2867         if (!err)
2868                 err = jbd2_journal_load(journal);
2869
2870         if (err) {
2871                 printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2872                 jbd2_journal_destroy(journal);
2873                 return err;
2874         }
2875
2876         EXT4_SB(sb)->s_journal = journal;
2877         ext4_clear_journal_err(sb, es);
2878
2879         if (journal_devnum &&
2880             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2881                 es->s_journal_dev = cpu_to_le32(journal_devnum);
2882                 sb->s_dirt = 1;
2883
2884                 /* Make sure we flush the recovery flag to disk. */
2885                 ext4_commit_super(sb, es, 1);
2886         }
2887
2888         return 0;
2889 }
2890
2891 static int ext4_commit_super(struct super_block *sb,
2892                               struct ext4_super_block *es, int sync)
2893 {
2894         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2895         int error = 0;
2896
2897         if (!sbh)
2898                 return error;
2899         if (buffer_write_io_error(sbh)) {
2900                 /*
2901                  * Oh, dear.  A previous attempt to write the
2902                  * superblock failed.  This could happen because the
2903                  * USB device was yanked out.  Or it could happen to
2904                  * be a transient write error and maybe the block will
2905                  * be remapped.  Nothing we can do but to retry the
2906                  * write and hope for the best.
2907                  */
2908                 printk(KERN_ERR "EXT4-fs: previous I/O error to "
2909                        "superblock detected for %s.\n", sb->s_id);
2910                 clear_buffer_write_io_error(sbh);
2911                 set_buffer_uptodate(sbh);
2912         }
2913         es->s_wtime = cpu_to_le32(get_seconds());
2914         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
2915                                         &EXT4_SB(sb)->s_freeblocks_counter));
2916         es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(
2917                                         &EXT4_SB(sb)->s_freeinodes_counter));
2918
2919         BUFFER_TRACE(sbh, "marking dirty");
2920         mark_buffer_dirty(sbh);
2921         if (sync) {
2922                 error = sync_dirty_buffer(sbh);
2923                 if (error)
2924                         return error;
2925
2926                 error = buffer_write_io_error(sbh);
2927                 if (error) {
2928                         printk(KERN_ERR "EXT4-fs: I/O error while writing "
2929                                "superblock for %s.\n", sb->s_id);
2930                         clear_buffer_write_io_error(sbh);
2931                         set_buffer_uptodate(sbh);
2932                 }
2933         }
2934         return error;
2935 }
2936
2937
2938 /*
2939  * Have we just finished recovery?  If so, and if we are mounting (or
2940  * remounting) the filesystem readonly, then we will end up with a
2941  * consistent fs on disk.  Record that fact.
2942  */
2943 static void ext4_mark_recovery_complete(struct super_block *sb,
2944                                         struct ext4_super_block *es)
2945 {
2946         journal_t *journal = EXT4_SB(sb)->s_journal;
2947
2948         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2949                 BUG_ON(journal != NULL);
2950                 return;
2951         }
2952         jbd2_journal_lock_updates(journal);
2953         if (jbd2_journal_flush(journal) < 0)
2954                 goto out;
2955
2956         lock_super(sb);
2957         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2958             sb->s_flags & MS_RDONLY) {
2959                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2960                 sb->s_dirt = 0;
2961                 ext4_commit_super(sb, es, 1);
2962         }
2963         unlock_super(sb);
2964
2965 out:
2966         jbd2_journal_unlock_updates(journal);
2967 }
2968
2969 /*
2970  * If we are mounting (or read-write remounting) a filesystem whose journal
2971  * has recorded an error from a previous lifetime, move that error to the
2972  * main filesystem now.
2973  */
2974 static void ext4_clear_journal_err(struct super_block *sb,
2975                                    struct ext4_super_block *es)
2976 {
2977         journal_t *journal;
2978         int j_errno;
2979         const char *errstr;
2980
2981         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2982
2983         journal = EXT4_SB(sb)->s_journal;
2984
2985         /*
2986          * Now check for any error status which may have been recorded in the
2987          * journal by a prior ext4_error() or ext4_abort()
2988          */
2989
2990         j_errno = jbd2_journal_errno(journal);
2991         if (j_errno) {
2992                 char nbuf[16];
2993
2994                 errstr = ext4_decode_error(sb, j_errno, nbuf);
2995                 ext4_warning(sb, __func__, "Filesystem error recorded "
2996                              "from previous mount: %s", errstr);
2997                 ext4_warning(sb, __func__, "Marking fs in need of "
2998                              "filesystem check.");
2999
3000                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
3001                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
3002                 ext4_commit_super(sb, es, 1);
3003
3004                 jbd2_journal_clear_err(journal);
3005         }
3006 }
3007
3008 /*
3009  * Force the running and committing transactions to commit,
3010  * and wait on the commit.
3011  */
3012 int ext4_force_commit(struct super_block *sb)
3013 {
3014         journal_t *journal;
3015         int ret = 0;
3016
3017         if (sb->s_flags & MS_RDONLY)
3018                 return 0;
3019
3020         journal = EXT4_SB(sb)->s_journal;
3021         if (journal) {
3022                 sb->s_dirt = 0;
3023                 ret = ext4_journal_force_commit(journal);
3024         }
3025
3026         return ret;
3027 }
3028
3029 /*
3030  * Ext4 always journals updates to the superblock itself, so we don't
3031  * have to propagate any other updates to the superblock on disk at this
3032  * point.  (We can probably nuke this function altogether, and remove
3033  * any mention to sb->s_dirt in all of fs/ext4; eventual cleanup...)
3034  */
3035 static void ext4_write_super(struct super_block *sb)
3036 {
3037         if (EXT4_SB(sb)->s_journal) {
3038                 if (mutex_trylock(&sb->s_lock) != 0)
3039                         BUG();
3040                 sb->s_dirt = 0;
3041         } else {
3042                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
3043         }
3044 }
3045
3046 static int ext4_sync_fs(struct super_block *sb, int wait)
3047 {
3048         int ret = 0;
3049         tid_t target;
3050
3051         trace_mark(ext4_sync_fs, "dev %s wait %d", sb->s_id, wait);
3052         sb->s_dirt = 0;
3053         if (EXT4_SB(sb)->s_journal) {
3054                 if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal,
3055                                               &target)) {
3056                         if (wait)
3057                                 jbd2_log_wait_commit(EXT4_SB(sb)->s_journal,
3058                                                      target);
3059                 }
3060         } else {
3061                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, wait);
3062         }
3063         return ret;
3064 }
3065
3066 /*
3067  * LVM calls this function before a (read-only) snapshot is created.  This
3068  * gives us a chance to flush the journal completely and mark the fs clean.
3069  */
3070 static int ext4_freeze(struct super_block *sb)
3071 {
3072         int error = 0;
3073         journal_t *journal;
3074         sb->s_dirt = 0;
3075
3076         if (!(sb->s_flags & MS_RDONLY)) {
3077                 journal = EXT4_SB(sb)->s_journal;
3078
3079                 if (journal) {
3080                         /* Now we set up the journal barrier. */
3081                         jbd2_journal_lock_updates(journal);
3082
3083                         /*
3084                          * We don't want to clear needs_recovery flag when we
3085                          * failed to flush the journal.
3086                          */
3087                         error = jbd2_journal_flush(journal);
3088                         if (error < 0)
3089                                 goto out;
3090                 }
3091
3092                 /* Journal blocked and flushed, clear needs_recovery flag. */
3093                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3094                 error = ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
3095                 if (error)
3096                         goto out;
3097         }
3098         return 0;
3099 out:
3100         jbd2_journal_unlock_updates(journal);
3101         return error;
3102 }
3103
3104 /*
3105  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
3106  * flag here, even though the filesystem is not technically dirty yet.
3107  */
3108 static int ext4_unfreeze(struct super_block *sb)
3109 {
3110         if (EXT4_SB(sb)->s_journal && !(sb->s_flags & MS_RDONLY)) {
3111                 lock_super(sb);
3112                 /* Reser the needs_recovery flag before the fs is unlocked. */
3113                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3114                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
3115                 unlock_super(sb);
3116                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3117         }
3118         return 0;
3119 }
3120
3121 static int ext4_remount(struct super_block *sb, int *flags, char *data)
3122 {
3123         struct ext4_super_block *es;
3124         struct ext4_sb_info *sbi = EXT4_SB(sb);
3125         ext4_fsblk_t n_blocks_count = 0;
3126         unsigned long old_sb_flags;
3127         struct ext4_mount_options old_opts;
3128         ext4_group_t g;
3129         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3130         int err;
3131 #ifdef CONFIG_QUOTA
3132         int i;
3133 #endif
3134
3135         /* Store the original options */
3136         old_sb_flags = sb->s_flags;
3137         old_opts.s_mount_opt = sbi->s_mount_opt;
3138         old_opts.s_resuid = sbi->s_resuid;
3139         old_opts.s_resgid = sbi->s_resgid;
3140         old_opts.s_commit_interval = sbi->s_commit_interval;
3141         old_opts.s_min_batch_time = sbi->s_min_batch_time;
3142         old_opts.s_max_batch_time = sbi->s_max_batch_time;
3143 #ifdef CONFIG_QUOTA
3144         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
3145         for (i = 0; i < MAXQUOTAS; i++)
3146                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
3147 #endif
3148         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
3149                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
3150
3151         /*
3152          * Allow the "check" option to be passed as a remount option.
3153          */
3154         if (!parse_options(data, sb, NULL, &journal_ioprio,
3155                            &n_blocks_count, 1)) {
3156                 err = -EINVAL;
3157                 goto restore_opts;
3158         }
3159
3160         if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
3161                 ext4_abort(sb, __func__, "Abort forced by user");
3162
3163         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3164                 ((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
3165
3166         es = sbi->s_es;
3167
3168         if (sbi->s_journal) {
3169                 ext4_init_journal_params(sb, sbi->s_journal);
3170                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3171         }
3172
3173         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
3174                 n_blocks_count > ext4_blocks_count(es)) {
3175                 if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
3176                         err = -EROFS;
3177                         goto restore_opts;
3178                 }
3179
3180                 if (*flags & MS_RDONLY) {
3181                         /*
3182                          * First of all, the unconditional stuff we have to do
3183                          * to disable replay of the journal when we next remount
3184                          */
3185                         sb->s_flags |= MS_RDONLY;
3186
3187                         /*
3188                          * OK, test if we are remounting a valid rw partition
3189                          * readonly, and if so set the rdonly flag and then
3190                          * mark the partition as valid again.
3191                          */
3192                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3193                             (sbi->s_mount_state & EXT4_VALID_FS))
3194                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
3195
3196                         /*
3197                          * We have to unlock super so that we can wait for
3198                          * transactions.
3199                          */
3200                         if (sbi->s_journal) {
3201                                 unlock_super(sb);
3202                                 ext4_mark_recovery_complete(sb, es);
3203                                 lock_super(sb);
3204                         }
3205                 } else {
3206                         int ret;
3207                         if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3208                                         ~EXT4_FEATURE_RO_COMPAT_SUPP))) {
3209                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
3210                                        "remount RDWR because of unsupported "
3211                                        "optional features (%x).\n", sb->s_id,
3212                                 (le32_to_cpu(sbi->s_es->s_feature_ro_compat) &
3213                                         ~EXT4_FEATURE_RO_COMPAT_SUPP));
3214                                 err = -EROFS;
3215                                 goto restore_opts;
3216                         }
3217
3218                         /*
3219                          * Make sure the group descriptor checksums
3220                          * are sane.  If they aren't, refuse to
3221                          * remount r/w.
3222                          */
3223                         for (g = 0; g < sbi->s_groups_count; g++) {
3224                                 struct ext4_group_desc *gdp =
3225                                         ext4_get_group_desc(sb, g, NULL);
3226
3227                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3228                                         printk(KERN_ERR
3229                "EXT4-fs: ext4_remount: "
3230                 "Checksum for group %u failed (%u!=%u)\n",
3231                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3232                                                le16_to_cpu(gdp->bg_checksum));
3233                                         err = -EINVAL;
3234                                         goto restore_opts;
3235                                 }
3236                         }
3237
3238                         /*
3239                          * If we have an unprocessed orphan list hanging
3240                          * around from a previously readonly bdev mount,
3241                          * require a full umount/remount for now.
3242                          */
3243                         if (es->s_last_orphan) {
3244                                 printk(KERN_WARNING "EXT4-fs: %s: couldn't "
3245                                        "remount RDWR because of unprocessed "
3246                                        "orphan inode list.  Please "
3247                                        "umount/remount instead.\n",
3248                                        sb->s_id);
3249                                 err = -EINVAL;
3250                                 goto restore_opts;
3251                         }
3252
3253                         /*
3254                          * Mounting a RDONLY partition read-write, so reread
3255                          * and store the current valid flag.  (It may have
3256                          * been changed by e2fsck since we originally mounted
3257                          * the partition.)
3258                          */
3259                         if (sbi->s_journal)
3260                                 ext4_clear_journal_err(sb, es);
3261                         sbi->s_mount_state = le16_to_cpu(es->s_state);
3262                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3263                                 goto restore_opts;
3264                         if (!ext4_setup_super(sb, es, 0))
3265                                 sb->s_flags &= ~MS_RDONLY;
3266                 }
3267         }
3268         if (sbi->s_journal == NULL)
3269                 ext4_commit_super(sb, es, 1);
3270
3271 #ifdef CONFIG_QUOTA
3272         /* Release old quota file names */
3273         for (i = 0; i < MAXQUOTAS; i++)
3274                 if (old_opts.s_qf_names[i] &&
3275                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3276                         kfree(old_opts.s_qf_names[i]);
3277 #endif
3278         return 0;
3279 restore_opts:
3280         sb->s_flags = old_sb_flags;
3281         sbi->s_mount_opt = old_opts.s_mount_opt;
3282         sbi->s_resuid = old_opts.s_resuid;
3283         sbi->s_resgid = old_opts.s_resgid;
3284         sbi->s_commit_interval = old_opts.s_commit_interval;
3285         sbi->s_min_batch_time = old_opts.s_min_batch_time;
3286         sbi->s_max_batch_time = old_opts.s_max_batch_time;
3287 #ifdef CONFIG_QUOTA
3288         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3289         for (i = 0; i < MAXQUOTAS; i++) {
3290                 if (sbi->s_qf_names[i] &&
3291                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3292                         kfree(sbi->s_qf_names[i]);
3293                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3294         }
3295 #endif
3296         return err;
3297 }
3298
3299 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
3300 {
3301         struct super_block *sb = dentry->d_sb;
3302         struct ext4_sb_info *sbi = EXT4_SB(sb);
3303         struct ext4_super_block *es = sbi->s_es;
3304         u64 fsid;
3305
3306         if (test_opt(sb, MINIX_DF)) {
3307                 sbi->s_overhead_last = 0;
3308         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3309                 ext4_group_t ngroups = sbi->s_groups_count, i;
3310                 ext4_fsblk_t overhead = 0;
3311                 smp_rmb();
3312
3313                 /*
3314                  * Compute the overhead (FS structures).  This is constant
3315                  * for a given filesystem unless the number of block groups
3316                  * changes so we cache the previous value until it does.
3317                  */
3318
3319                 /*
3320                  * All of the blocks before first_data_block are
3321                  * overhead
3322                  */
3323                 overhead = le32_to_cpu(es->s_first_data_block);
3324
3325                 /*
3326                  * Add the overhead attributed to the superblock and
3327                  * block group descriptors.  If the sparse superblocks
3328                  * feature is turned on, then not all groups have this.
3329                  */
3330                 for (i = 0; i < ngroups; i++) {
3331                         overhead += ext4_bg_has_super(sb, i) +
3332                                 ext4_bg_num_gdb(sb, i);
3333                         cond_resched();
3334                 }
3335
3336                 /*
3337                  * Every block group has an inode bitmap, a block
3338                  * bitmap, and an inode table.
3339                  */
3340                 overhead += ngroups * (2 + sbi->s_itb_per_group);
3341                 sbi->s_overhead_last = overhead;
3342                 smp_wmb();
3343                 sbi->s_blocks_last = ext4_blocks_count(es);
3344         }
3345
3346         buf->f_type = EXT4_SUPER_MAGIC;
3347         buf->f_bsize = sb->s_blocksize;
3348         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3349         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
3350                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
3351         ext4_free_blocks_count_set(es, buf->f_bfree);
3352         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3353         if (buf->f_bfree < ext4_r_blocks_count(es))
3354                 buf->f_bavail = 0;
3355         buf->f_files = le32_to_cpu(es->s_inodes_count);
3356         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3357         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
3358         buf->f_namelen = EXT4_NAME_LEN;
3359         fsid = le64_to_cpup((void *)es->s_uuid) ^
3360                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3361         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3362         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3363         return 0;
3364 }
3365
3366 /* Helper function for writing quotas on sync - we need to start transaction before quota file
3367  * is locked for write. Otherwise the are possible deadlocks:
3368  * Process 1                         Process 2
3369  * ext4_create()                     quota_sync()
3370  *   jbd2_journal_start()                   write_dquot()
3371  *   DQUOT_INIT()                        down(dqio_mutex)
3372  *     down(dqio_mutex)                    jbd2_journal_start()
3373  *
3374  */
3375
3376 #ifdef CONFIG_QUOTA
3377
3378 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3379 {
3380         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3381 }
3382
3383 static int ext4_dquot_initialize(struct inode *inode, int type)
3384 {
3385         handle_t *handle;
3386         int ret, err;
3387
3388         /* We may create quota structure so we need to reserve enough blocks */
3389         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
3390         if (IS_ERR(handle))
3391                 return PTR_ERR(handle);
3392         ret = dquot_initialize(inode, type);
3393         err = ext4_journal_stop(handle);
3394         if (!ret)
3395                 ret = err;
3396         return ret;
3397 }
3398
3399 static int ext4_dquot_drop(struct inode *inode)
3400 {
3401         handle_t *handle;
3402         int ret, err;
3403
3404         /* We may delete quota structure so we need to reserve enough blocks */
3405         handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
3406         if (IS_ERR(handle)) {
3407                 /*
3408                  * We call dquot_drop() anyway to at least release references
3409                  * to quota structures so that umount does not hang.
3410                  */
3411                 dquot_drop(inode);
3412                 return PTR_ERR(handle);
3413         }
3414         ret = dquot_drop(inode);
3415         err = ext4_journal_stop(handle);
3416         if (!ret)
3417                 ret = err;
3418         return ret;
3419 }
3420
3421 static int ext4_write_dquot(struct dquot *dquot)
3422 {
3423         int ret, err;
3424         handle_t *handle;
3425         struct inode *inode;
3426
3427         inode = dquot_to_inode(dquot);
3428         handle = ext4_journal_start(inode,
3429                                         EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3430         if (IS_ERR(handle))
3431                 return PTR_ERR(handle);
3432         ret = dquot_commit(dquot);
3433         err = ext4_journal_stop(handle);
3434         if (!ret)
3435                 ret = err;
3436         return ret;
3437 }
3438
3439 static int ext4_acquire_dquot(struct dquot *dquot)
3440 {
3441         int ret, err;
3442         handle_t *handle;
3443
3444         handle = ext4_journal_start(dquot_to_inode(dquot),
3445                                         EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3446         if (IS_ERR(handle))
3447                 return PTR_ERR(handle);
3448         ret = dquot_acquire(dquot);
3449         err = ext4_journal_stop(handle);
3450         if (!ret)
3451                 ret = err;
3452         return ret;
3453 }
3454
3455 static int ext4_release_dquot(struct dquot *dquot)
3456 {
3457         int ret, err;
3458         handle_t *handle;
3459
3460         handle = ext4_journal_start(dquot_to_inode(dquot),
3461                                         EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3462         if (IS_ERR(handle)) {
3463                 /* Release dquot anyway to avoid endless cycle in dqput() */
3464                 dquot_release(dquot);
3465                 return PTR_ERR(handle);
3466         }
3467         ret = dquot_release(dquot);
3468         err = ext4_journal_stop(handle);
3469         if (!ret)
3470                 ret = err;
3471         return ret;
3472 }
3473
3474 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3475 {
3476         /* Are we journaling quotas? */
3477         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3478             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3479                 dquot_mark_dquot_dirty(dquot);
3480                 return ext4_write_dquot(dquot);
3481         } else {
3482                 return dquot_mark_dquot_dirty(dquot);
3483         }
3484 }
3485
3486 static int ext4_write_info(struct super_block *sb, int type)
3487 {
3488         int ret, err;
3489         handle_t *handle;
3490
3491         /* Data block + inode block */
3492         handle = ext4_journal_start(sb->s_root->d_inode, 2);
3493         if (IS_ERR(handle))
3494                 return PTR_ERR(handle);
3495         ret = dquot_commit_info(sb, type);
3496         err = ext4_journal_stop(handle);
3497         if (!ret)
3498                 ret = err;
3499         return ret;
3500 }
3501
3502 /*
3503  * Turn on quotas during mount time - we need to find
3504  * the quota file and such...
3505  */
3506 static int ext4_quota_on_mount(struct super_block *sb, int type)
3507 {
3508         return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3509                         EXT4_SB(sb)->s_jquota_fmt, type);
3510 }
3511
3512 /*
3513  * Standard function to be called on quota_on
3514  */
3515 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3516                          char *name, int remount)
3517 {
3518         int err;
3519         struct path path;
3520
3521         if (!test_opt(sb, QUOTA))
3522                 return -EINVAL;
3523         /* When remounting, no checks are needed and in fact, name is NULL */
3524         if (remount)
3525                 return vfs_quota_on(sb, type, format_id, name, remount);
3526
3527         err = kern_path(name, LOOKUP_FOLLOW, &path);
3528         if (err)
3529                 return err;
3530
3531         /* Quotafile not on the same filesystem? */
3532         if (path.mnt->mnt_sb != sb) {
3533                 path_put(&path);
3534                 return -EXDEV;
3535         }
3536         /* Journaling quota? */
3537         if (EXT4_SB(sb)->s_qf_names[type]) {
3538                 /* Quotafile not in fs root? */
3539                 if (path.dentry->d_parent != sb->s_root)
3540                         printk(KERN_WARNING
3541                                 "EXT4-fs: Quota file not on filesystem root. "
3542                                 "Journaled quota will not work.\n");
3543         }
3544
3545         /*
3546          * When we journal data on quota file, we have to flush journal to see
3547          * all updates to the file when we bypass pagecache...
3548          */
3549         if (EXT4_SB(sb)->s_journal &&
3550             ext4_should_journal_data(path.dentry->d_inode)) {
3551                 /*
3552                  * We don't need to lock updates but journal_flush() could
3553                  * otherwise be livelocked...
3554                  */
3555                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3556                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3557                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3558                 if (err) {
3559                         path_put(&path);
3560                         return err;
3561                 }
3562         }
3563
3564         err = vfs_quota_on_path(sb, type, format_id, &path);
3565         path_put(&path);
3566         return err;
3567 }
3568
3569 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3570  * acquiring the locks... As quota files are never truncated and quota code
3571  * itself serializes the operations (and noone else should touch the files)
3572  * we don't have to be afraid of races */
3573 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3574                                size_t len, loff_t off)
3575 {
3576         struct inode *inode = sb_dqopt(sb)->files[type];
3577         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3578         int err = 0;
3579         int offset = off & (sb->s_blocksize - 1);
3580         int tocopy;
3581         size_t toread;
3582         struct buffer_head *bh;
3583         loff_t i_size = i_size_read(inode);
3584
3585         if (off > i_size)
3586                 return 0;
3587         if (off+len > i_size)
3588                 len = i_size-off;
3589         toread = len;
3590         while (toread > 0) {
3591                 tocopy = sb->s_blocksize - offset < toread ?
3592                                 sb->s_blocksize - offset : toread;
3593                 bh = ext4_bread(NULL, inode, blk, 0, &err);
3594                 if (err)
3595                         return err;
3596                 if (!bh)        /* A hole? */
3597                         memset(data, 0, tocopy);
3598                 else
3599                         memcpy(data, bh->b_data+offset, tocopy);
3600                 brelse(bh);
3601                 offset = 0;
3602                 toread -= tocopy;
3603                 data += tocopy;
3604                 blk++;
3605         }
3606         return len;
3607 }
3608
3609 /* Write to quotafile (we know the transaction is already started and has
3610  * enough credits) */
3611 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3612                                 const char *data, size_t len, loff_t off)
3613 {
3614         struct inode *inode = sb_dqopt(sb)->files[type];
3615         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3616         int err = 0;
3617         int offset = off & (sb->s_blocksize - 1);
3618         int tocopy;
3619         int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3620         size_t towrite = len;
3621         struct buffer_head *bh;
3622         handle_t *handle = journal_current_handle();
3623
3624         if (EXT4_SB(sb)->s_journal && !handle) {
3625                 printk(KERN_WARNING "EXT4-fs: Quota write (off=%llu, len=%llu)"
3626                         " cancelled because transaction is not started.\n",
3627                         (unsigned long long)off, (unsigned long long)len);
3628                 return -EIO;
3629         }
3630         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3631         while (towrite > 0) {
3632                 tocopy = sb->s_blocksize - offset < towrite ?
3633                                 sb->s_blocksize - offset : towrite;
3634                 bh = ext4_bread(handle, inode, blk, 1, &err);
3635                 if (!bh)
3636                         goto out;
3637                 if (journal_quota) {
3638                         err = ext4_journal_get_write_access(handle, bh);
3639                         if (err) {
3640                                 brelse(bh);
3641                                 goto out;
3642                         }
3643                 }
3644                 lock_buffer(bh);
3645                 memcpy(bh->b_data+offset, data, tocopy);
3646                 flush_dcache_page(bh->b_page);
3647                 unlock_buffer(bh);
3648                 if (journal_quota)
3649                         err = ext4_handle_dirty_metadata(handle, NULL, bh);
3650                 else {
3651                         /* Always do at least ordered writes for quotas */
3652                         err = ext4_jbd2_file_inode(handle, inode);
3653                         mark_buffer_dirty(bh);
3654                 }
3655                 brelse(bh);
3656                 if (err)
3657                         goto out;
3658                 offset = 0;
3659                 towrite -= tocopy;
3660                 data += tocopy;
3661                 blk++;
3662         }
3663 out:
3664         if (len == towrite) {
3665                 mutex_unlock(&inode->i_mutex);
3666                 return err;
3667         }
3668         if (inode->i_size < off+len-towrite) {
3669                 i_size_write(inode, off+len-towrite);
3670                 EXT4_I(inode)->i_disksize = inode->i_size;
3671         }
3672         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3673         ext4_mark_inode_dirty(handle, inode);
3674         mutex_unlock(&inode->i_mutex);
3675         return len - towrite;
3676 }
3677
3678 #endif
3679
3680 static int ext4_get_sb(struct file_system_type *fs_type,
3681         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3682 {
3683         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3684 }
3685
3686 #ifdef CONFIG_PROC_FS
3687 static int ext4_ui_proc_show(struct seq_file *m, void *v)
3688 {
3689         unsigned int *p = m->private;
3690
3691         seq_printf(m, "%u\n", *p);
3692         return 0;
3693 }
3694
3695 static int ext4_ui_proc_open(struct inode *inode, struct file *file)
3696 {
3697         return single_open(file, ext4_ui_proc_show, PDE(inode)->data);
3698 }
3699
3700 static ssize_t ext4_ui_proc_write(struct file *file, const char __user *buf,
3701                                size_t cnt, loff_t *ppos)
3702 {
3703         unsigned long *p = PDE(file->f_path.dentry->d_inode)->data;
3704         char str[32];
3705
3706         if (cnt >= sizeof(str))
3707                 return -EINVAL;
3708         if (copy_from_user(str, buf, cnt))
3709                 return -EFAULT;
3710
3711         *p = simple_strtoul(str, NULL, 0);
3712         return cnt;
3713 }
3714
3715 const struct file_operations ext4_ui_proc_fops = {
3716         .owner          = THIS_MODULE,
3717         .open           = ext4_ui_proc_open,
3718         .read           = seq_read,
3719         .llseek         = seq_lseek,
3720         .release        = single_release,
3721         .write          = ext4_ui_proc_write,
3722 };
3723 #endif
3724
3725 static struct file_system_type ext4_fs_type = {
3726         .owner          = THIS_MODULE,
3727         .name           = "ext4",
3728         .get_sb         = ext4_get_sb,
3729         .kill_sb        = kill_block_super,
3730         .fs_flags       = FS_REQUIRES_DEV,
3731 };
3732
3733 #ifdef CONFIG_EXT4DEV_COMPAT
3734 static int ext4dev_get_sb(struct file_system_type *fs_type,
3735         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
3736 {
3737         printk(KERN_WARNING "EXT4-fs: Update your userspace programs "
3738                "to mount using ext4\n");
3739         printk(KERN_WARNING "EXT4-fs: ext4dev backwards compatibility "
3740                "will go away by 2.6.31\n");
3741         return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
3742 }
3743
3744 static struct file_system_type ext4dev_fs_type = {
3745         .owner          = THIS_MODULE,
3746         .name           = "ext4dev",
3747         .get_sb         = ext4dev_get_sb,
3748         .kill_sb        = kill_block_super,
3749         .fs_flags       = FS_REQUIRES_DEV,
3750 };
3751 MODULE_ALIAS("ext4dev");
3752 #endif
3753
3754 static int __init init_ext4_fs(void)
3755 {
3756         int err;
3757
3758         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
3759         err = init_ext4_mballoc();
3760         if (err)
3761                 return err;
3762
3763         err = init_ext4_xattr();
3764         if (err)
3765                 goto out2;
3766         err = init_inodecache();
3767         if (err)
3768                 goto out1;
3769         err = register_filesystem(&ext4_fs_type);
3770         if (err)
3771                 goto out;
3772 #ifdef CONFIG_EXT4DEV_COMPAT
3773         err = register_filesystem(&ext4dev_fs_type);
3774         if (err) {
3775                 unregister_filesystem(&ext4_fs_type);
3776                 goto out;
3777         }
3778 #endif
3779         return 0;
3780 out:
3781         destroy_inodecache();
3782 out1:
3783         exit_ext4_xattr();
3784 out2:
3785         exit_ext4_mballoc();
3786         return err;
3787 }
3788
3789 static void __exit exit_ext4_fs(void)
3790 {
3791         unregister_filesystem(&ext4_fs_type);
3792 #ifdef CONFIG_EXT4DEV_COMPAT
3793         unregister_filesystem(&ext4dev_fs_type);
3794 #endif
3795         destroy_inodecache();
3796         exit_ext4_xattr();
3797         exit_ext4_mballoc();
3798         remove_proc_entry("fs/ext4", NULL);
3799 }
3800
3801 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
3802 MODULE_DESCRIPTION("Fourth Extended Filesystem");
3803 MODULE_LICENSE("GPL");
3804 module_init(init_ext4_fs)
3805 module_exit(exit_ext4_fs)