xref: /linux/fs/ext4/super.c (revision f8343685643f2901fe11aa9d0358cafbeaf7b4c3)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/jbd2.h>
24 #include <linux/ext4_fs.h>
25 #include <linux/ext4_jbd2.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/blkdev.h>
29 #include <linux/parser.h>
30 #include <linux/smp_lock.h>
31 #include <linux/buffer_head.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 
39 #include <asm/uaccess.h>
40 
41 #include "xattr.h"
42 #include "acl.h"
43 #include "namei.h"
44 
45 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
46 			     unsigned long journal_devnum);
47 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
48 			       unsigned int);
49 static void ext4_commit_super (struct super_block * sb,
50 			       struct ext4_super_block * es,
51 			       int sync);
52 static void ext4_mark_recovery_complete(struct super_block * sb,
53 					struct ext4_super_block * es);
54 static void ext4_clear_journal_err(struct super_block * sb,
55 				   struct ext4_super_block * es);
56 static int ext4_sync_fs(struct super_block *sb, int wait);
57 static const char *ext4_decode_error(struct super_block * sb, int errno,
58 				     char nbuf[16]);
59 static int ext4_remount (struct super_block * sb, int * flags, char * data);
60 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
61 static void ext4_unlockfs(struct super_block *sb);
62 static void ext4_write_super (struct super_block * sb);
63 static void ext4_write_super_lockfs(struct super_block *sb);
64 
65 
66 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
67 			       struct ext4_group_desc *bg)
68 {
69 	return le32_to_cpu(bg->bg_block_bitmap) |
70 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
71 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
72 }
73 
74 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
75 			       struct ext4_group_desc *bg)
76 {
77 	return le32_to_cpu(bg->bg_inode_bitmap) |
78 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
79 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
80 }
81 
82 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
83 			      struct ext4_group_desc *bg)
84 {
85 	return le32_to_cpu(bg->bg_inode_table) |
86 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
87 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
88 }
89 
90 void ext4_block_bitmap_set(struct super_block *sb,
91 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
92 {
93 	bg->bg_block_bitmap = cpu_to_le32((u32)blk);
94 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
95 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
96 }
97 
98 void ext4_inode_bitmap_set(struct super_block *sb,
99 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
100 {
101 	bg->bg_inode_bitmap  = cpu_to_le32((u32)blk);
102 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
103 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
104 }
105 
106 void ext4_inode_table_set(struct super_block *sb,
107 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
108 {
109 	bg->bg_inode_table = cpu_to_le32((u32)blk);
110 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
111 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
112 }
113 
114 /*
115  * Wrappers for jbd2_journal_start/end.
116  *
117  * The only special thing we need to do here is to make sure that all
118  * journal_end calls result in the superblock being marked dirty, so
119  * that sync() will call the filesystem's write_super callback if
120  * appropriate.
121  */
122 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
123 {
124 	journal_t *journal;
125 
126 	if (sb->s_flags & MS_RDONLY)
127 		return ERR_PTR(-EROFS);
128 
129 	/* Special case here: if the journal has aborted behind our
130 	 * backs (eg. EIO in the commit thread), then we still need to
131 	 * take the FS itself readonly cleanly. */
132 	journal = EXT4_SB(sb)->s_journal;
133 	if (is_journal_aborted(journal)) {
134 		ext4_abort(sb, __FUNCTION__,
135 			   "Detected aborted journal");
136 		return ERR_PTR(-EROFS);
137 	}
138 
139 	return jbd2_journal_start(journal, nblocks);
140 }
141 
142 /*
143  * The only special thing we need to do here is to make sure that all
144  * jbd2_journal_stop calls result in the superblock being marked dirty, so
145  * that sync() will call the filesystem's write_super callback if
146  * appropriate.
147  */
148 int __ext4_journal_stop(const char *where, handle_t *handle)
149 {
150 	struct super_block *sb;
151 	int err;
152 	int rc;
153 
154 	sb = handle->h_transaction->t_journal->j_private;
155 	err = handle->h_err;
156 	rc = jbd2_journal_stop(handle);
157 
158 	if (!err)
159 		err = rc;
160 	if (err)
161 		__ext4_std_error(sb, where, err);
162 	return err;
163 }
164 
165 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
166 		struct buffer_head *bh, handle_t *handle, int err)
167 {
168 	char nbuf[16];
169 	const char *errstr = ext4_decode_error(NULL, err, nbuf);
170 
171 	if (bh)
172 		BUFFER_TRACE(bh, "abort");
173 
174 	if (!handle->h_err)
175 		handle->h_err = err;
176 
177 	if (is_handle_aborted(handle))
178 		return;
179 
180 	printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
181 	       caller, errstr, err_fn);
182 
183 	jbd2_journal_abort_handle(handle);
184 }
185 
186 /* Deal with the reporting of failure conditions on a filesystem such as
187  * inconsistencies detected or read IO failures.
188  *
189  * On ext2, we can store the error state of the filesystem in the
190  * superblock.  That is not possible on ext4, because we may have other
191  * write ordering constraints on the superblock which prevent us from
192  * writing it out straight away; and given that the journal is about to
193  * be aborted, we can't rely on the current, or future, transactions to
194  * write out the superblock safely.
195  *
196  * We'll just use the jbd2_journal_abort() error code to record an error in
197  * the journal instead.  On recovery, the journal will compain about
198  * that error until we've noted it down and cleared it.
199  */
200 
201 static void ext4_handle_error(struct super_block *sb)
202 {
203 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
204 
205 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
206 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
207 
208 	if (sb->s_flags & MS_RDONLY)
209 		return;
210 
211 	if (!test_opt (sb, ERRORS_CONT)) {
212 		journal_t *journal = EXT4_SB(sb)->s_journal;
213 
214 		EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
215 		if (journal)
216 			jbd2_journal_abort(journal, -EIO);
217 	}
218 	if (test_opt (sb, ERRORS_RO)) {
219 		printk (KERN_CRIT "Remounting filesystem read-only\n");
220 		sb->s_flags |= MS_RDONLY;
221 	}
222 	ext4_commit_super(sb, es, 1);
223 	if (test_opt(sb, ERRORS_PANIC))
224 		panic("EXT4-fs (device %s): panic forced after error\n",
225 			sb->s_id);
226 }
227 
228 void ext4_error (struct super_block * sb, const char * function,
229 		 const char * fmt, ...)
230 {
231 	va_list args;
232 
233 	va_start(args, fmt);
234 	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
235 	vprintk(fmt, args);
236 	printk("\n");
237 	va_end(args);
238 
239 	ext4_handle_error(sb);
240 }
241 
242 static const char *ext4_decode_error(struct super_block * sb, int errno,
243 				     char nbuf[16])
244 {
245 	char *errstr = NULL;
246 
247 	switch (errno) {
248 	case -EIO:
249 		errstr = "IO failure";
250 		break;
251 	case -ENOMEM:
252 		errstr = "Out of memory";
253 		break;
254 	case -EROFS:
255 		if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
256 			errstr = "Journal has aborted";
257 		else
258 			errstr = "Readonly filesystem";
259 		break;
260 	default:
261 		/* If the caller passed in an extra buffer for unknown
262 		 * errors, textualise them now.  Else we just return
263 		 * NULL. */
264 		if (nbuf) {
265 			/* Check for truncated error codes... */
266 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
267 				errstr = nbuf;
268 		}
269 		break;
270 	}
271 
272 	return errstr;
273 }
274 
275 /* __ext4_std_error decodes expected errors from journaling functions
276  * automatically and invokes the appropriate error response.  */
277 
278 void __ext4_std_error (struct super_block * sb, const char * function,
279 		       int errno)
280 {
281 	char nbuf[16];
282 	const char *errstr;
283 
284 	/* Special case: if the error is EROFS, and we're not already
285 	 * inside a transaction, then there's really no point in logging
286 	 * an error. */
287 	if (errno == -EROFS && journal_current_handle() == NULL &&
288 	    (sb->s_flags & MS_RDONLY))
289 		return;
290 
291 	errstr = ext4_decode_error(sb, errno, nbuf);
292 	printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
293 		sb->s_id, function, errstr);
294 
295 	ext4_handle_error(sb);
296 }
297 
298 /*
299  * ext4_abort is a much stronger failure handler than ext4_error.  The
300  * abort function may be used to deal with unrecoverable failures such
301  * as journal IO errors or ENOMEM at a critical moment in log management.
302  *
303  * We unconditionally force the filesystem into an ABORT|READONLY state,
304  * unless the error response on the fs has been set to panic in which
305  * case we take the easy way out and panic immediately.
306  */
307 
308 void ext4_abort (struct super_block * sb, const char * function,
309 		 const char * fmt, ...)
310 {
311 	va_list args;
312 
313 	printk (KERN_CRIT "ext4_abort called.\n");
314 
315 	va_start(args, fmt);
316 	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
317 	vprintk(fmt, args);
318 	printk("\n");
319 	va_end(args);
320 
321 	if (test_opt(sb, ERRORS_PANIC))
322 		panic("EXT4-fs panic from previous error\n");
323 
324 	if (sb->s_flags & MS_RDONLY)
325 		return;
326 
327 	printk(KERN_CRIT "Remounting filesystem read-only\n");
328 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
329 	sb->s_flags |= MS_RDONLY;
330 	EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
331 	jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
332 }
333 
334 void ext4_warning (struct super_block * sb, const char * function,
335 		   const char * fmt, ...)
336 {
337 	va_list args;
338 
339 	va_start(args, fmt);
340 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
341 	       sb->s_id, function);
342 	vprintk(fmt, args);
343 	printk("\n");
344 	va_end(args);
345 }
346 
347 void ext4_update_dynamic_rev(struct super_block *sb)
348 {
349 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
350 
351 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
352 		return;
353 
354 	ext4_warning(sb, __FUNCTION__,
355 		     "updating to rev %d because of new feature flag, "
356 		     "running e2fsck is recommended",
357 		     EXT4_DYNAMIC_REV);
358 
359 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
360 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
361 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
362 	/* leave es->s_feature_*compat flags alone */
363 	/* es->s_uuid will be set by e2fsck if empty */
364 
365 	/*
366 	 * The rest of the superblock fields should be zero, and if not it
367 	 * means they are likely already in use, so leave them alone.  We
368 	 * can leave it up to e2fsck to clean up any inconsistencies there.
369 	 */
370 }
371 
372 /*
373  * Open the external journal device
374  */
375 static struct block_device *ext4_blkdev_get(dev_t dev)
376 {
377 	struct block_device *bdev;
378 	char b[BDEVNAME_SIZE];
379 
380 	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
381 	if (IS_ERR(bdev))
382 		goto fail;
383 	return bdev;
384 
385 fail:
386 	printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
387 			__bdevname(dev, b), PTR_ERR(bdev));
388 	return NULL;
389 }
390 
391 /*
392  * Release the journal device
393  */
394 static int ext4_blkdev_put(struct block_device *bdev)
395 {
396 	bd_release(bdev);
397 	return blkdev_put(bdev);
398 }
399 
400 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
401 {
402 	struct block_device *bdev;
403 	int ret = -ENODEV;
404 
405 	bdev = sbi->journal_bdev;
406 	if (bdev) {
407 		ret = ext4_blkdev_put(bdev);
408 		sbi->journal_bdev = NULL;
409 	}
410 	return ret;
411 }
412 
413 static inline struct inode *orphan_list_entry(struct list_head *l)
414 {
415 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
416 }
417 
418 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
419 {
420 	struct list_head *l;
421 
422 	printk(KERN_ERR "sb orphan head is %d\n",
423 	       le32_to_cpu(sbi->s_es->s_last_orphan));
424 
425 	printk(KERN_ERR "sb_info orphan list:\n");
426 	list_for_each(l, &sbi->s_orphan) {
427 		struct inode *inode = orphan_list_entry(l);
428 		printk(KERN_ERR "  "
429 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
430 		       inode->i_sb->s_id, inode->i_ino, inode,
431 		       inode->i_mode, inode->i_nlink,
432 		       NEXT_ORPHAN(inode));
433 	}
434 }
435 
436 static void ext4_put_super (struct super_block * sb)
437 {
438 	struct ext4_sb_info *sbi = EXT4_SB(sb);
439 	struct ext4_super_block *es = sbi->s_es;
440 	int i;
441 
442 	ext4_ext_release(sb);
443 	ext4_xattr_put_super(sb);
444 	jbd2_journal_destroy(sbi->s_journal);
445 	if (!(sb->s_flags & MS_RDONLY)) {
446 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
447 		es->s_state = cpu_to_le16(sbi->s_mount_state);
448 		BUFFER_TRACE(sbi->s_sbh, "marking dirty");
449 		mark_buffer_dirty(sbi->s_sbh);
450 		ext4_commit_super(sb, es, 1);
451 	}
452 
453 	for (i = 0; i < sbi->s_gdb_count; i++)
454 		brelse(sbi->s_group_desc[i]);
455 	kfree(sbi->s_group_desc);
456 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
457 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
458 	percpu_counter_destroy(&sbi->s_dirs_counter);
459 	brelse(sbi->s_sbh);
460 #ifdef CONFIG_QUOTA
461 	for (i = 0; i < MAXQUOTAS; i++)
462 		kfree(sbi->s_qf_names[i]);
463 #endif
464 
465 	/* Debugging code just in case the in-memory inode orphan list
466 	 * isn't empty.  The on-disk one can be non-empty if we've
467 	 * detected an error and taken the fs readonly, but the
468 	 * in-memory list had better be clean by this point. */
469 	if (!list_empty(&sbi->s_orphan))
470 		dump_orphan_list(sb, sbi);
471 	J_ASSERT(list_empty(&sbi->s_orphan));
472 
473 	invalidate_bdev(sb->s_bdev);
474 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
475 		/*
476 		 * Invalidate the journal device's buffers.  We don't want them
477 		 * floating about in memory - the physical journal device may
478 		 * hotswapped, and it breaks the `ro-after' testing code.
479 		 */
480 		sync_blockdev(sbi->journal_bdev);
481 		invalidate_bdev(sbi->journal_bdev);
482 		ext4_blkdev_remove(sbi);
483 	}
484 	sb->s_fs_info = NULL;
485 	kfree(sbi);
486 	return;
487 }
488 
489 static struct kmem_cache *ext4_inode_cachep;
490 
491 /*
492  * Called inside transaction, so use GFP_NOFS
493  */
494 static struct inode *ext4_alloc_inode(struct super_block *sb)
495 {
496 	struct ext4_inode_info *ei;
497 
498 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
499 	if (!ei)
500 		return NULL;
501 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
502 	ei->i_acl = EXT4_ACL_NOT_CACHED;
503 	ei->i_default_acl = EXT4_ACL_NOT_CACHED;
504 #endif
505 	ei->i_block_alloc_info = NULL;
506 	ei->vfs_inode.i_version = 1;
507 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
508 	return &ei->vfs_inode;
509 }
510 
511 static void ext4_destroy_inode(struct inode *inode)
512 {
513 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
514 }
515 
516 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
517 {
518 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
519 
520 	INIT_LIST_HEAD(&ei->i_orphan);
521 #ifdef CONFIG_EXT4DEV_FS_XATTR
522 	init_rwsem(&ei->xattr_sem);
523 #endif
524 	mutex_init(&ei->truncate_mutex);
525 	inode_init_once(&ei->vfs_inode);
526 }
527 
528 static int init_inodecache(void)
529 {
530 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
531 					     sizeof(struct ext4_inode_info),
532 					     0, (SLAB_RECLAIM_ACCOUNT|
533 						SLAB_MEM_SPREAD),
534 					     init_once, NULL);
535 	if (ext4_inode_cachep == NULL)
536 		return -ENOMEM;
537 	return 0;
538 }
539 
540 static void destroy_inodecache(void)
541 {
542 	kmem_cache_destroy(ext4_inode_cachep);
543 }
544 
545 static void ext4_clear_inode(struct inode *inode)
546 {
547 	struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
548 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
549 	if (EXT4_I(inode)->i_acl &&
550 			EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
551 		posix_acl_release(EXT4_I(inode)->i_acl);
552 		EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
553 	}
554 	if (EXT4_I(inode)->i_default_acl &&
555 			EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
556 		posix_acl_release(EXT4_I(inode)->i_default_acl);
557 		EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
558 	}
559 #endif
560 	ext4_discard_reservation(inode);
561 	EXT4_I(inode)->i_block_alloc_info = NULL;
562 	if (unlikely(rsv))
563 		kfree(rsv);
564 }
565 
566 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
567 {
568 #if defined(CONFIG_QUOTA)
569 	struct ext4_sb_info *sbi = EXT4_SB(sb);
570 
571 	if (sbi->s_jquota_fmt)
572 		seq_printf(seq, ",jqfmt=%s",
573 		(sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
574 
575 	if (sbi->s_qf_names[USRQUOTA])
576 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
577 
578 	if (sbi->s_qf_names[GRPQUOTA])
579 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
580 
581 	if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
582 		seq_puts(seq, ",usrquota");
583 
584 	if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
585 		seq_puts(seq, ",grpquota");
586 #endif
587 }
588 
589 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
590 {
591 	struct super_block *sb = vfs->mnt_sb;
592 
593 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
594 		seq_puts(seq, ",data=journal");
595 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
596 		seq_puts(seq, ",data=ordered");
597 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
598 		seq_puts(seq, ",data=writeback");
599 
600 	ext4_show_quota_options(seq, sb);
601 
602 	return 0;
603 }
604 
605 
606 static struct dentry *ext4_get_dentry(struct super_block *sb, void *vobjp)
607 {
608 	__u32 *objp = vobjp;
609 	unsigned long ino = objp[0];
610 	__u32 generation = objp[1];
611 	struct inode *inode;
612 	struct dentry *result;
613 
614 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
615 		return ERR_PTR(-ESTALE);
616 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
617 		return ERR_PTR(-ESTALE);
618 
619 	/* iget isn't really right if the inode is currently unallocated!!
620 	 *
621 	 * ext4_read_inode will return a bad_inode if the inode had been
622 	 * deleted, so we should be safe.
623 	 *
624 	 * Currently we don't know the generation for parent directory, so
625 	 * a generation of 0 means "accept any"
626 	 */
627 	inode = iget(sb, ino);
628 	if (inode == NULL)
629 		return ERR_PTR(-ENOMEM);
630 	if (is_bad_inode(inode) ||
631 	    (generation && inode->i_generation != generation)) {
632 		iput(inode);
633 		return ERR_PTR(-ESTALE);
634 	}
635 	/* now to find a dentry.
636 	 * If possible, get a well-connected one
637 	 */
638 	result = d_alloc_anon(inode);
639 	if (!result) {
640 		iput(inode);
641 		return ERR_PTR(-ENOMEM);
642 	}
643 	return result;
644 }
645 
646 #ifdef CONFIG_QUOTA
647 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
648 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
649 
650 static int ext4_dquot_initialize(struct inode *inode, int type);
651 static int ext4_dquot_drop(struct inode *inode);
652 static int ext4_write_dquot(struct dquot *dquot);
653 static int ext4_acquire_dquot(struct dquot *dquot);
654 static int ext4_release_dquot(struct dquot *dquot);
655 static int ext4_mark_dquot_dirty(struct dquot *dquot);
656 static int ext4_write_info(struct super_block *sb, int type);
657 static int ext4_quota_on(struct super_block *sb, int type, int format_id, char *path);
658 static int ext4_quota_on_mount(struct super_block *sb, int type);
659 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
660 			       size_t len, loff_t off);
661 static ssize_t ext4_quota_write(struct super_block *sb, int type,
662 				const char *data, size_t len, loff_t off);
663 
664 static struct dquot_operations ext4_quota_operations = {
665 	.initialize	= ext4_dquot_initialize,
666 	.drop		= ext4_dquot_drop,
667 	.alloc_space	= dquot_alloc_space,
668 	.alloc_inode	= dquot_alloc_inode,
669 	.free_space	= dquot_free_space,
670 	.free_inode	= dquot_free_inode,
671 	.transfer	= dquot_transfer,
672 	.write_dquot	= ext4_write_dquot,
673 	.acquire_dquot	= ext4_acquire_dquot,
674 	.release_dquot	= ext4_release_dquot,
675 	.mark_dirty	= ext4_mark_dquot_dirty,
676 	.write_info	= ext4_write_info
677 };
678 
679 static struct quotactl_ops ext4_qctl_operations = {
680 	.quota_on	= ext4_quota_on,
681 	.quota_off	= vfs_quota_off,
682 	.quota_sync	= vfs_quota_sync,
683 	.get_info	= vfs_get_dqinfo,
684 	.set_info	= vfs_set_dqinfo,
685 	.get_dqblk	= vfs_get_dqblk,
686 	.set_dqblk	= vfs_set_dqblk
687 };
688 #endif
689 
690 static const struct super_operations ext4_sops = {
691 	.alloc_inode	= ext4_alloc_inode,
692 	.destroy_inode	= ext4_destroy_inode,
693 	.read_inode	= ext4_read_inode,
694 	.write_inode	= ext4_write_inode,
695 	.dirty_inode	= ext4_dirty_inode,
696 	.delete_inode	= ext4_delete_inode,
697 	.put_super	= ext4_put_super,
698 	.write_super	= ext4_write_super,
699 	.sync_fs	= ext4_sync_fs,
700 	.write_super_lockfs = ext4_write_super_lockfs,
701 	.unlockfs	= ext4_unlockfs,
702 	.statfs		= ext4_statfs,
703 	.remount_fs	= ext4_remount,
704 	.clear_inode	= ext4_clear_inode,
705 	.show_options	= ext4_show_options,
706 #ifdef CONFIG_QUOTA
707 	.quota_read	= ext4_quota_read,
708 	.quota_write	= ext4_quota_write,
709 #endif
710 };
711 
712 static struct export_operations ext4_export_ops = {
713 	.get_parent = ext4_get_parent,
714 	.get_dentry = ext4_get_dentry,
715 };
716 
717 enum {
718 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
719 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
720 	Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
721 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
722 	Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
723 	Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
724 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
725 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
726 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
727 	Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
728 	Opt_grpquota, Opt_extents,
729 };
730 
731 static match_table_t tokens = {
732 	{Opt_bsd_df, "bsddf"},
733 	{Opt_minix_df, "minixdf"},
734 	{Opt_grpid, "grpid"},
735 	{Opt_grpid, "bsdgroups"},
736 	{Opt_nogrpid, "nogrpid"},
737 	{Opt_nogrpid, "sysvgroups"},
738 	{Opt_resgid, "resgid=%u"},
739 	{Opt_resuid, "resuid=%u"},
740 	{Opt_sb, "sb=%u"},
741 	{Opt_err_cont, "errors=continue"},
742 	{Opt_err_panic, "errors=panic"},
743 	{Opt_err_ro, "errors=remount-ro"},
744 	{Opt_nouid32, "nouid32"},
745 	{Opt_nocheck, "nocheck"},
746 	{Opt_nocheck, "check=none"},
747 	{Opt_debug, "debug"},
748 	{Opt_oldalloc, "oldalloc"},
749 	{Opt_orlov, "orlov"},
750 	{Opt_user_xattr, "user_xattr"},
751 	{Opt_nouser_xattr, "nouser_xattr"},
752 	{Opt_acl, "acl"},
753 	{Opt_noacl, "noacl"},
754 	{Opt_reservation, "reservation"},
755 	{Opt_noreservation, "noreservation"},
756 	{Opt_noload, "noload"},
757 	{Opt_nobh, "nobh"},
758 	{Opt_bh, "bh"},
759 	{Opt_commit, "commit=%u"},
760 	{Opt_journal_update, "journal=update"},
761 	{Opt_journal_inum, "journal=%u"},
762 	{Opt_journal_dev, "journal_dev=%u"},
763 	{Opt_abort, "abort"},
764 	{Opt_data_journal, "data=journal"},
765 	{Opt_data_ordered, "data=ordered"},
766 	{Opt_data_writeback, "data=writeback"},
767 	{Opt_offusrjquota, "usrjquota="},
768 	{Opt_usrjquota, "usrjquota=%s"},
769 	{Opt_offgrpjquota, "grpjquota="},
770 	{Opt_grpjquota, "grpjquota=%s"},
771 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
772 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
773 	{Opt_grpquota, "grpquota"},
774 	{Opt_noquota, "noquota"},
775 	{Opt_quota, "quota"},
776 	{Opt_usrquota, "usrquota"},
777 	{Opt_barrier, "barrier=%u"},
778 	{Opt_extents, "extents"},
779 	{Opt_err, NULL},
780 	{Opt_resize, "resize"},
781 };
782 
783 static ext4_fsblk_t get_sb_block(void **data)
784 {
785 	ext4_fsblk_t	sb_block;
786 	char		*options = (char *) *data;
787 
788 	if (!options || strncmp(options, "sb=", 3) != 0)
789 		return 1;	/* Default location */
790 	options += 3;
791 	/*todo: use simple_strtoll with >32bit ext4 */
792 	sb_block = simple_strtoul(options, &options, 0);
793 	if (*options && *options != ',') {
794 		printk("EXT4-fs: Invalid sb specification: %s\n",
795 		       (char *) *data);
796 		return 1;
797 	}
798 	if (*options == ',')
799 		options++;
800 	*data = (void *) options;
801 	return sb_block;
802 }
803 
804 static int parse_options (char *options, struct super_block *sb,
805 			  unsigned int *inum, unsigned long *journal_devnum,
806 			  ext4_fsblk_t *n_blocks_count, int is_remount)
807 {
808 	struct ext4_sb_info *sbi = EXT4_SB(sb);
809 	char * p;
810 	substring_t args[MAX_OPT_ARGS];
811 	int data_opt = 0;
812 	int option;
813 #ifdef CONFIG_QUOTA
814 	int qtype;
815 	char *qname;
816 #endif
817 
818 	if (!options)
819 		return 1;
820 
821 	while ((p = strsep (&options, ",")) != NULL) {
822 		int token;
823 		if (!*p)
824 			continue;
825 
826 		token = match_token(p, tokens, args);
827 		switch (token) {
828 		case Opt_bsd_df:
829 			clear_opt (sbi->s_mount_opt, MINIX_DF);
830 			break;
831 		case Opt_minix_df:
832 			set_opt (sbi->s_mount_opt, MINIX_DF);
833 			break;
834 		case Opt_grpid:
835 			set_opt (sbi->s_mount_opt, GRPID);
836 			break;
837 		case Opt_nogrpid:
838 			clear_opt (sbi->s_mount_opt, GRPID);
839 			break;
840 		case Opt_resuid:
841 			if (match_int(&args[0], &option))
842 				return 0;
843 			sbi->s_resuid = option;
844 			break;
845 		case Opt_resgid:
846 			if (match_int(&args[0], &option))
847 				return 0;
848 			sbi->s_resgid = option;
849 			break;
850 		case Opt_sb:
851 			/* handled by get_sb_block() instead of here */
852 			/* *sb_block = match_int(&args[0]); */
853 			break;
854 		case Opt_err_panic:
855 			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
856 			clear_opt (sbi->s_mount_opt, ERRORS_RO);
857 			set_opt (sbi->s_mount_opt, ERRORS_PANIC);
858 			break;
859 		case Opt_err_ro:
860 			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
861 			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
862 			set_opt (sbi->s_mount_opt, ERRORS_RO);
863 			break;
864 		case Opt_err_cont:
865 			clear_opt (sbi->s_mount_opt, ERRORS_RO);
866 			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
867 			set_opt (sbi->s_mount_opt, ERRORS_CONT);
868 			break;
869 		case Opt_nouid32:
870 			set_opt (sbi->s_mount_opt, NO_UID32);
871 			break;
872 		case Opt_nocheck:
873 			clear_opt (sbi->s_mount_opt, CHECK);
874 			break;
875 		case Opt_debug:
876 			set_opt (sbi->s_mount_opt, DEBUG);
877 			break;
878 		case Opt_oldalloc:
879 			set_opt (sbi->s_mount_opt, OLDALLOC);
880 			break;
881 		case Opt_orlov:
882 			clear_opt (sbi->s_mount_opt, OLDALLOC);
883 			break;
884 #ifdef CONFIG_EXT4DEV_FS_XATTR
885 		case Opt_user_xattr:
886 			set_opt (sbi->s_mount_opt, XATTR_USER);
887 			break;
888 		case Opt_nouser_xattr:
889 			clear_opt (sbi->s_mount_opt, XATTR_USER);
890 			break;
891 #else
892 		case Opt_user_xattr:
893 		case Opt_nouser_xattr:
894 			printk("EXT4 (no)user_xattr options not supported\n");
895 			break;
896 #endif
897 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
898 		case Opt_acl:
899 			set_opt(sbi->s_mount_opt, POSIX_ACL);
900 			break;
901 		case Opt_noacl:
902 			clear_opt(sbi->s_mount_opt, POSIX_ACL);
903 			break;
904 #else
905 		case Opt_acl:
906 		case Opt_noacl:
907 			printk("EXT4 (no)acl options not supported\n");
908 			break;
909 #endif
910 		case Opt_reservation:
911 			set_opt(sbi->s_mount_opt, RESERVATION);
912 			break;
913 		case Opt_noreservation:
914 			clear_opt(sbi->s_mount_opt, RESERVATION);
915 			break;
916 		case Opt_journal_update:
917 			/* @@@ FIXME */
918 			/* Eventually we will want to be able to create
919 			   a journal file here.  For now, only allow the
920 			   user to specify an existing inode to be the
921 			   journal file. */
922 			if (is_remount) {
923 				printk(KERN_ERR "EXT4-fs: cannot specify "
924 				       "journal on remount\n");
925 				return 0;
926 			}
927 			set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
928 			break;
929 		case Opt_journal_inum:
930 			if (is_remount) {
931 				printk(KERN_ERR "EXT4-fs: cannot specify "
932 				       "journal on remount\n");
933 				return 0;
934 			}
935 			if (match_int(&args[0], &option))
936 				return 0;
937 			*inum = option;
938 			break;
939 		case Opt_journal_dev:
940 			if (is_remount) {
941 				printk(KERN_ERR "EXT4-fs: cannot specify "
942 				       "journal on remount\n");
943 				return 0;
944 			}
945 			if (match_int(&args[0], &option))
946 				return 0;
947 			*journal_devnum = option;
948 			break;
949 		case Opt_noload:
950 			set_opt (sbi->s_mount_opt, NOLOAD);
951 			break;
952 		case Opt_commit:
953 			if (match_int(&args[0], &option))
954 				return 0;
955 			if (option < 0)
956 				return 0;
957 			if (option == 0)
958 				option = JBD_DEFAULT_MAX_COMMIT_AGE;
959 			sbi->s_commit_interval = HZ * option;
960 			break;
961 		case Opt_data_journal:
962 			data_opt = EXT4_MOUNT_JOURNAL_DATA;
963 			goto datacheck;
964 		case Opt_data_ordered:
965 			data_opt = EXT4_MOUNT_ORDERED_DATA;
966 			goto datacheck;
967 		case Opt_data_writeback:
968 			data_opt = EXT4_MOUNT_WRITEBACK_DATA;
969 		datacheck:
970 			if (is_remount) {
971 				if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
972 						!= data_opt) {
973 					printk(KERN_ERR
974 						"EXT4-fs: cannot change data "
975 						"mode on remount\n");
976 					return 0;
977 				}
978 			} else {
979 				sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
980 				sbi->s_mount_opt |= data_opt;
981 			}
982 			break;
983 #ifdef CONFIG_QUOTA
984 		case Opt_usrjquota:
985 			qtype = USRQUOTA;
986 			goto set_qf_name;
987 		case Opt_grpjquota:
988 			qtype = GRPQUOTA;
989 set_qf_name:
990 			if (sb_any_quota_enabled(sb)) {
991 				printk(KERN_ERR
992 					"EXT4-fs: Cannot change journalled "
993 					"quota options when quota turned on.\n");
994 				return 0;
995 			}
996 			qname = match_strdup(&args[0]);
997 			if (!qname) {
998 				printk(KERN_ERR
999 					"EXT4-fs: not enough memory for "
1000 					"storing quotafile name.\n");
1001 				return 0;
1002 			}
1003 			if (sbi->s_qf_names[qtype] &&
1004 			    strcmp(sbi->s_qf_names[qtype], qname)) {
1005 				printk(KERN_ERR
1006 					"EXT4-fs: %s quota file already "
1007 					"specified.\n", QTYPE2NAME(qtype));
1008 				kfree(qname);
1009 				return 0;
1010 			}
1011 			sbi->s_qf_names[qtype] = qname;
1012 			if (strchr(sbi->s_qf_names[qtype], '/')) {
1013 				printk(KERN_ERR
1014 					"EXT4-fs: quotafile must be on "
1015 					"filesystem root.\n");
1016 				kfree(sbi->s_qf_names[qtype]);
1017 				sbi->s_qf_names[qtype] = NULL;
1018 				return 0;
1019 			}
1020 			set_opt(sbi->s_mount_opt, QUOTA);
1021 			break;
1022 		case Opt_offusrjquota:
1023 			qtype = USRQUOTA;
1024 			goto clear_qf_name;
1025 		case Opt_offgrpjquota:
1026 			qtype = GRPQUOTA;
1027 clear_qf_name:
1028 			if (sb_any_quota_enabled(sb)) {
1029 				printk(KERN_ERR "EXT4-fs: Cannot change "
1030 					"journalled quota options when "
1031 					"quota turned on.\n");
1032 				return 0;
1033 			}
1034 			/*
1035 			 * The space will be released later when all options
1036 			 * are confirmed to be correct
1037 			 */
1038 			sbi->s_qf_names[qtype] = NULL;
1039 			break;
1040 		case Opt_jqfmt_vfsold:
1041 			sbi->s_jquota_fmt = QFMT_VFS_OLD;
1042 			break;
1043 		case Opt_jqfmt_vfsv0:
1044 			sbi->s_jquota_fmt = QFMT_VFS_V0;
1045 			break;
1046 		case Opt_quota:
1047 		case Opt_usrquota:
1048 			set_opt(sbi->s_mount_opt, QUOTA);
1049 			set_opt(sbi->s_mount_opt, USRQUOTA);
1050 			break;
1051 		case Opt_grpquota:
1052 			set_opt(sbi->s_mount_opt, QUOTA);
1053 			set_opt(sbi->s_mount_opt, GRPQUOTA);
1054 			break;
1055 		case Opt_noquota:
1056 			if (sb_any_quota_enabled(sb)) {
1057 				printk(KERN_ERR "EXT4-fs: Cannot change quota "
1058 					"options when quota turned on.\n");
1059 				return 0;
1060 			}
1061 			clear_opt(sbi->s_mount_opt, QUOTA);
1062 			clear_opt(sbi->s_mount_opt, USRQUOTA);
1063 			clear_opt(sbi->s_mount_opt, GRPQUOTA);
1064 			break;
1065 #else
1066 		case Opt_quota:
1067 		case Opt_usrquota:
1068 		case Opt_grpquota:
1069 		case Opt_usrjquota:
1070 		case Opt_grpjquota:
1071 		case Opt_offusrjquota:
1072 		case Opt_offgrpjquota:
1073 		case Opt_jqfmt_vfsold:
1074 		case Opt_jqfmt_vfsv0:
1075 			printk(KERN_ERR
1076 				"EXT4-fs: journalled quota options not "
1077 				"supported.\n");
1078 			break;
1079 		case Opt_noquota:
1080 			break;
1081 #endif
1082 		case Opt_abort:
1083 			set_opt(sbi->s_mount_opt, ABORT);
1084 			break;
1085 		case Opt_barrier:
1086 			if (match_int(&args[0], &option))
1087 				return 0;
1088 			if (option)
1089 				set_opt(sbi->s_mount_opt, BARRIER);
1090 			else
1091 				clear_opt(sbi->s_mount_opt, BARRIER);
1092 			break;
1093 		case Opt_ignore:
1094 			break;
1095 		case Opt_resize:
1096 			if (!is_remount) {
1097 				printk("EXT4-fs: resize option only available "
1098 					"for remount\n");
1099 				return 0;
1100 			}
1101 			if (match_int(&args[0], &option) != 0)
1102 				return 0;
1103 			*n_blocks_count = option;
1104 			break;
1105 		case Opt_nobh:
1106 			set_opt(sbi->s_mount_opt, NOBH);
1107 			break;
1108 		case Opt_bh:
1109 			clear_opt(sbi->s_mount_opt, NOBH);
1110 			break;
1111 		case Opt_extents:
1112 			set_opt (sbi->s_mount_opt, EXTENTS);
1113 			break;
1114 		default:
1115 			printk (KERN_ERR
1116 				"EXT4-fs: Unrecognized mount option \"%s\" "
1117 				"or missing value\n", p);
1118 			return 0;
1119 		}
1120 	}
1121 #ifdef CONFIG_QUOTA
1122 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1123 		if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1124 		     sbi->s_qf_names[USRQUOTA])
1125 			clear_opt(sbi->s_mount_opt, USRQUOTA);
1126 
1127 		if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1128 		     sbi->s_qf_names[GRPQUOTA])
1129 			clear_opt(sbi->s_mount_opt, GRPQUOTA);
1130 
1131 		if ((sbi->s_qf_names[USRQUOTA] &&
1132 				(sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1133 		    (sbi->s_qf_names[GRPQUOTA] &&
1134 				(sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1135 			printk(KERN_ERR "EXT4-fs: old and new quota "
1136 					"format mixing.\n");
1137 			return 0;
1138 		}
1139 
1140 		if (!sbi->s_jquota_fmt) {
1141 			printk(KERN_ERR "EXT4-fs: journalled quota format "
1142 					"not specified.\n");
1143 			return 0;
1144 		}
1145 	} else {
1146 		if (sbi->s_jquota_fmt) {
1147 			printk(KERN_ERR "EXT4-fs: journalled quota format "
1148 					"specified with no journalling "
1149 					"enabled.\n");
1150 			return 0;
1151 		}
1152 	}
1153 #endif
1154 	return 1;
1155 }
1156 
1157 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1158 			    int read_only)
1159 {
1160 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1161 	int res = 0;
1162 
1163 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1164 		printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1165 			"forcing read-only mode\n");
1166 		res = MS_RDONLY;
1167 	}
1168 	if (read_only)
1169 		return res;
1170 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1171 		printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1172 			"running e2fsck is recommended\n");
1173 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1174 		printk (KERN_WARNING
1175 			"EXT4-fs warning: mounting fs with errors, "
1176 			"running e2fsck is recommended\n");
1177 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1178 		 le16_to_cpu(es->s_mnt_count) >=
1179 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1180 		printk (KERN_WARNING
1181 			"EXT4-fs warning: maximal mount count reached, "
1182 			"running e2fsck is recommended\n");
1183 	else if (le32_to_cpu(es->s_checkinterval) &&
1184 		(le32_to_cpu(es->s_lastcheck) +
1185 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1186 		printk (KERN_WARNING
1187 			"EXT4-fs warning: checktime reached, "
1188 			"running e2fsck is recommended\n");
1189 #if 0
1190 		/* @@@ We _will_ want to clear the valid bit if we find
1191 		 * inconsistencies, to force a fsck at reboot.  But for
1192 		 * a plain journaled filesystem we can keep it set as
1193 		 * valid forever! :)
1194 		 */
1195 	es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT4_VALID_FS);
1196 #endif
1197 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1198 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1199 	es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
1200 	es->s_mtime = cpu_to_le32(get_seconds());
1201 	ext4_update_dynamic_rev(sb);
1202 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1203 
1204 	ext4_commit_super(sb, es, 1);
1205 	if (test_opt(sb, DEBUG))
1206 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1207 				"bpg=%lu, ipg=%lu, mo=%04lx]\n",
1208 			sb->s_blocksize,
1209 			sbi->s_groups_count,
1210 			EXT4_BLOCKS_PER_GROUP(sb),
1211 			EXT4_INODES_PER_GROUP(sb),
1212 			sbi->s_mount_opt);
1213 
1214 	printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1215 	if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1216 		char b[BDEVNAME_SIZE];
1217 
1218 		printk("external journal on %s\n",
1219 			bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1220 	} else {
1221 		printk("internal journal\n");
1222 	}
1223 	return res;
1224 }
1225 
1226 /* Called at mount-time, super-block is locked */
1227 static int ext4_check_descriptors (struct super_block * sb)
1228 {
1229 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1230 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1231 	ext4_fsblk_t last_block;
1232 	ext4_fsblk_t block_bitmap;
1233 	ext4_fsblk_t inode_bitmap;
1234 	ext4_fsblk_t inode_table;
1235 	struct ext4_group_desc * gdp = NULL;
1236 	int desc_block = 0;
1237 	int i;
1238 
1239 	ext4_debug ("Checking group descriptors");
1240 
1241 	for (i = 0; i < sbi->s_groups_count; i++)
1242 	{
1243 		if (i == sbi->s_groups_count - 1)
1244 			last_block = ext4_blocks_count(sbi->s_es) - 1;
1245 		else
1246 			last_block = first_block +
1247 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
1248 
1249 		if ((i % EXT4_DESC_PER_BLOCK(sb)) == 0)
1250 			gdp = (struct ext4_group_desc *)
1251 					sbi->s_group_desc[desc_block++]->b_data;
1252 		block_bitmap = ext4_block_bitmap(sb, gdp);
1253 		if (block_bitmap < first_block || block_bitmap > last_block)
1254 		{
1255 			ext4_error (sb, "ext4_check_descriptors",
1256 				    "Block bitmap for group %d"
1257 				    " not in group (block %llu)!",
1258 				    i, block_bitmap);
1259 			return 0;
1260 		}
1261 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
1262 		if (inode_bitmap < first_block || inode_bitmap > last_block)
1263 		{
1264 			ext4_error (sb, "ext4_check_descriptors",
1265 				    "Inode bitmap for group %d"
1266 				    " not in group (block %llu)!",
1267 				    i, inode_bitmap);
1268 			return 0;
1269 		}
1270 		inode_table = ext4_inode_table(sb, gdp);
1271 		if (inode_table < first_block ||
1272 		    inode_table + sbi->s_itb_per_group > last_block)
1273 		{
1274 			ext4_error (sb, "ext4_check_descriptors",
1275 				    "Inode table for group %d"
1276 				    " not in group (block %llu)!",
1277 				    i, inode_table);
1278 			return 0;
1279 		}
1280 		first_block += EXT4_BLOCKS_PER_GROUP(sb);
1281 		gdp = (struct ext4_group_desc *)
1282 			((__u8 *)gdp + EXT4_DESC_SIZE(sb));
1283 	}
1284 
1285 	ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1286 	sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1287 	return 1;
1288 }
1289 
1290 
1291 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1292  * the superblock) which were deleted from all directories, but held open by
1293  * a process at the time of a crash.  We walk the list and try to delete these
1294  * inodes at recovery time (only with a read-write filesystem).
1295  *
1296  * In order to keep the orphan inode chain consistent during traversal (in
1297  * case of crash during recovery), we link each inode into the superblock
1298  * orphan list_head and handle it the same way as an inode deletion during
1299  * normal operation (which journals the operations for us).
1300  *
1301  * We only do an iget() and an iput() on each inode, which is very safe if we
1302  * accidentally point at an in-use or already deleted inode.  The worst that
1303  * can happen in this case is that we get a "bit already cleared" message from
1304  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1305  * e2fsck was run on this filesystem, and it must have already done the orphan
1306  * inode cleanup for us, so we can safely abort without any further action.
1307  */
1308 static void ext4_orphan_cleanup (struct super_block * sb,
1309 				 struct ext4_super_block * es)
1310 {
1311 	unsigned int s_flags = sb->s_flags;
1312 	int nr_orphans = 0, nr_truncates = 0;
1313 #ifdef CONFIG_QUOTA
1314 	int i;
1315 #endif
1316 	if (!es->s_last_orphan) {
1317 		jbd_debug(4, "no orphan inodes to clean up\n");
1318 		return;
1319 	}
1320 
1321 	if (bdev_read_only(sb->s_bdev)) {
1322 		printk(KERN_ERR "EXT4-fs: write access "
1323 			"unavailable, skipping orphan cleanup.\n");
1324 		return;
1325 	}
1326 
1327 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1328 		if (es->s_last_orphan)
1329 			jbd_debug(1, "Errors on filesystem, "
1330 				  "clearing orphan list.\n");
1331 		es->s_last_orphan = 0;
1332 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1333 		return;
1334 	}
1335 
1336 	if (s_flags & MS_RDONLY) {
1337 		printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1338 		       sb->s_id);
1339 		sb->s_flags &= ~MS_RDONLY;
1340 	}
1341 #ifdef CONFIG_QUOTA
1342 	/* Needed for iput() to work correctly and not trash data */
1343 	sb->s_flags |= MS_ACTIVE;
1344 	/* Turn on quotas so that they are updated correctly */
1345 	for (i = 0; i < MAXQUOTAS; i++) {
1346 		if (EXT4_SB(sb)->s_qf_names[i]) {
1347 			int ret = ext4_quota_on_mount(sb, i);
1348 			if (ret < 0)
1349 				printk(KERN_ERR
1350 					"EXT4-fs: Cannot turn on journalled "
1351 					"quota: error %d\n", ret);
1352 		}
1353 	}
1354 #endif
1355 
1356 	while (es->s_last_orphan) {
1357 		struct inode *inode;
1358 
1359 		if (!(inode =
1360 		      ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
1361 			es->s_last_orphan = 0;
1362 			break;
1363 		}
1364 
1365 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1366 		DQUOT_INIT(inode);
1367 		if (inode->i_nlink) {
1368 			printk(KERN_DEBUG
1369 				"%s: truncating inode %lu to %Ld bytes\n",
1370 				__FUNCTION__, inode->i_ino, inode->i_size);
1371 			jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1372 				  inode->i_ino, inode->i_size);
1373 			ext4_truncate(inode);
1374 			nr_truncates++;
1375 		} else {
1376 			printk(KERN_DEBUG
1377 				"%s: deleting unreferenced inode %lu\n",
1378 				__FUNCTION__, inode->i_ino);
1379 			jbd_debug(2, "deleting unreferenced inode %lu\n",
1380 				  inode->i_ino);
1381 			nr_orphans++;
1382 		}
1383 		iput(inode);  /* The delete magic happens here! */
1384 	}
1385 
1386 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1387 
1388 	if (nr_orphans)
1389 		printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1390 		       sb->s_id, PLURAL(nr_orphans));
1391 	if (nr_truncates)
1392 		printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1393 		       sb->s_id, PLURAL(nr_truncates));
1394 #ifdef CONFIG_QUOTA
1395 	/* Turn quotas off */
1396 	for (i = 0; i < MAXQUOTAS; i++) {
1397 		if (sb_dqopt(sb)->files[i])
1398 			vfs_quota_off(sb, i);
1399 	}
1400 #endif
1401 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1402 }
1403 
1404 #define log2(n) ffz(~(n))
1405 
1406 /*
1407  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
1408  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
1409  * We need to be 1 filesystem block less than the 2^32 sector limit.
1410  */
1411 static loff_t ext4_max_size(int bits)
1412 {
1413 	loff_t res = EXT4_NDIR_BLOCKS;
1414 	/* This constant is calculated to be the largest file size for a
1415 	 * dense, 4k-blocksize file such that the total number of
1416 	 * sectors in the file, including data and all indirect blocks,
1417 	 * does not exceed 2^32. */
1418 	const loff_t upper_limit = 0x1ff7fffd000LL;
1419 
1420 	res += 1LL << (bits-2);
1421 	res += 1LL << (2*(bits-2));
1422 	res += 1LL << (3*(bits-2));
1423 	res <<= bits;
1424 	if (res > upper_limit)
1425 		res = upper_limit;
1426 	return res;
1427 }
1428 
1429 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1430 				ext4_fsblk_t logical_sb_block, int nr)
1431 {
1432 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1433 	unsigned long bg, first_meta_bg;
1434 	int has_super = 0;
1435 
1436 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1437 
1438 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1439 	    nr < first_meta_bg)
1440 		return logical_sb_block + nr + 1;
1441 	bg = sbi->s_desc_per_block * nr;
1442 	if (ext4_bg_has_super(sb, bg))
1443 		has_super = 1;
1444 	return (has_super + ext4_group_first_block_no(sb, bg));
1445 }
1446 
1447 
1448 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1449 {
1450 	struct buffer_head * bh;
1451 	struct ext4_super_block *es = NULL;
1452 	struct ext4_sb_info *sbi;
1453 	ext4_fsblk_t block;
1454 	ext4_fsblk_t sb_block = get_sb_block(&data);
1455 	ext4_fsblk_t logical_sb_block;
1456 	unsigned long offset = 0;
1457 	unsigned int journal_inum = 0;
1458 	unsigned long journal_devnum = 0;
1459 	unsigned long def_mount_opts;
1460 	struct inode *root;
1461 	int blocksize;
1462 	int hblock;
1463 	int db_count;
1464 	int i;
1465 	int needs_recovery;
1466 	__le32 features;
1467 	__u64 blocks_count;
1468 
1469 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1470 	if (!sbi)
1471 		return -ENOMEM;
1472 	sb->s_fs_info = sbi;
1473 	sbi->s_mount_opt = 0;
1474 	sbi->s_resuid = EXT4_DEF_RESUID;
1475 	sbi->s_resgid = EXT4_DEF_RESGID;
1476 
1477 	unlock_kernel();
1478 
1479 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1480 	if (!blocksize) {
1481 		printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1482 		goto out_fail;
1483 	}
1484 
1485 	/*
1486 	 * The ext4 superblock will not be buffer aligned for other than 1kB
1487 	 * block sizes.  We need to calculate the offset from buffer start.
1488 	 */
1489 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1490 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1491 		offset = do_div(logical_sb_block, blocksize);
1492 	} else {
1493 		logical_sb_block = sb_block;
1494 	}
1495 
1496 	if (!(bh = sb_bread(sb, logical_sb_block))) {
1497 		printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1498 		goto out_fail;
1499 	}
1500 	/*
1501 	 * Note: s_es must be initialized as soon as possible because
1502 	 *       some ext4 macro-instructions depend on its value
1503 	 */
1504 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1505 	sbi->s_es = es;
1506 	sb->s_magic = le16_to_cpu(es->s_magic);
1507 	if (sb->s_magic != EXT4_SUPER_MAGIC)
1508 		goto cantfind_ext4;
1509 
1510 	/* Set defaults before we parse the mount options */
1511 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1512 	if (def_mount_opts & EXT4_DEFM_DEBUG)
1513 		set_opt(sbi->s_mount_opt, DEBUG);
1514 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1515 		set_opt(sbi->s_mount_opt, GRPID);
1516 	if (def_mount_opts & EXT4_DEFM_UID16)
1517 		set_opt(sbi->s_mount_opt, NO_UID32);
1518 #ifdef CONFIG_EXT4DEV_FS_XATTR
1519 	if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1520 		set_opt(sbi->s_mount_opt, XATTR_USER);
1521 #endif
1522 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1523 	if (def_mount_opts & EXT4_DEFM_ACL)
1524 		set_opt(sbi->s_mount_opt, POSIX_ACL);
1525 #endif
1526 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1527 		sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1528 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1529 		sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1530 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1531 		sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1532 
1533 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1534 		set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1535 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_RO)
1536 		set_opt(sbi->s_mount_opt, ERRORS_RO);
1537 	else
1538 		set_opt(sbi->s_mount_opt, ERRORS_CONT);
1539 
1540 	sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1541 	sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1542 
1543 	set_opt(sbi->s_mount_opt, RESERVATION);
1544 
1545 	if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1546 			    NULL, 0))
1547 		goto failed_mount;
1548 
1549 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1550 		((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1551 
1552 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1553 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1554 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1555 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1556 		printk(KERN_WARNING
1557 		       "EXT4-fs warning: feature flags set on rev 0 fs, "
1558 		       "running e2fsck is recommended\n");
1559 	/*
1560 	 * Check feature flags regardless of the revision level, since we
1561 	 * previously didn't change the revision level when setting the flags,
1562 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
1563 	 */
1564 	features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1565 	if (features) {
1566 		printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1567 		       "unsupported optional features (%x).\n",
1568 		       sb->s_id, le32_to_cpu(features));
1569 		goto failed_mount;
1570 	}
1571 	features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1572 	if (!(sb->s_flags & MS_RDONLY) && features) {
1573 		printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1574 		       "unsupported optional features (%x).\n",
1575 		       sb->s_id, le32_to_cpu(features));
1576 		goto failed_mount;
1577 	}
1578 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1579 
1580 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1581 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
1582 		printk(KERN_ERR
1583 		       "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1584 		       blocksize, sb->s_id);
1585 		goto failed_mount;
1586 	}
1587 
1588 	hblock = bdev_hardsect_size(sb->s_bdev);
1589 	if (sb->s_blocksize != blocksize) {
1590 		/*
1591 		 * Make sure the blocksize for the filesystem is larger
1592 		 * than the hardware sectorsize for the machine.
1593 		 */
1594 		if (blocksize < hblock) {
1595 			printk(KERN_ERR "EXT4-fs: blocksize %d too small for "
1596 			       "device blocksize %d.\n", blocksize, hblock);
1597 			goto failed_mount;
1598 		}
1599 
1600 		brelse (bh);
1601 		sb_set_blocksize(sb, blocksize);
1602 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1603 		offset = do_div(logical_sb_block, blocksize);
1604 		bh = sb_bread(sb, logical_sb_block);
1605 		if (!bh) {
1606 			printk(KERN_ERR
1607 			       "EXT4-fs: Can't read superblock on 2nd try.\n");
1608 			goto failed_mount;
1609 		}
1610 		es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1611 		sbi->s_es = es;
1612 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1613 			printk (KERN_ERR
1614 				"EXT4-fs: Magic mismatch, very weird !\n");
1615 			goto failed_mount;
1616 		}
1617 	}
1618 
1619 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
1620 
1621 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
1622 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
1623 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
1624 	} else {
1625 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1626 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1627 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
1628 		    (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
1629 		    (sbi->s_inode_size > blocksize)) {
1630 			printk (KERN_ERR
1631 				"EXT4-fs: unsupported inode size: %d\n",
1632 				sbi->s_inode_size);
1633 			goto failed_mount;
1634 		}
1635 	}
1636 	sbi->s_frag_size = EXT4_MIN_FRAG_SIZE <<
1637 				   le32_to_cpu(es->s_log_frag_size);
1638 	if (blocksize != sbi->s_frag_size) {
1639 		printk(KERN_ERR
1640 		       "EXT4-fs: fragsize %lu != blocksize %u (unsupported)\n",
1641 		       sbi->s_frag_size, blocksize);
1642 		goto failed_mount;
1643 	}
1644 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
1645 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
1646 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
1647 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
1648 		    sbi->s_desc_size & (sbi->s_desc_size - 1)) {
1649 			printk(KERN_ERR
1650 			       "EXT4-fs: unsupported descriptor size %lu\n",
1651 			       sbi->s_desc_size);
1652 			goto failed_mount;
1653 		}
1654 	} else
1655 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
1656 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1657 	sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1658 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1659 	if (EXT4_INODE_SIZE(sb) == 0)
1660 		goto cantfind_ext4;
1661 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
1662 	if (sbi->s_inodes_per_block == 0)
1663 		goto cantfind_ext4;
1664 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
1665 					sbi->s_inodes_per_block;
1666 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
1667 	sbi->s_sbh = bh;
1668 	sbi->s_mount_state = le16_to_cpu(es->s_state);
1669 	sbi->s_addr_per_block_bits = log2(EXT4_ADDR_PER_BLOCK(sb));
1670 	sbi->s_desc_per_block_bits = log2(EXT4_DESC_PER_BLOCK(sb));
1671 	for (i=0; i < 4; i++)
1672 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
1673 	sbi->s_def_hash_version = es->s_def_hash_version;
1674 
1675 	if (sbi->s_blocks_per_group > blocksize * 8) {
1676 		printk (KERN_ERR
1677 			"EXT4-fs: #blocks per group too big: %lu\n",
1678 			sbi->s_blocks_per_group);
1679 		goto failed_mount;
1680 	}
1681 	if (sbi->s_frags_per_group > blocksize * 8) {
1682 		printk (KERN_ERR
1683 			"EXT4-fs: #fragments per group too big: %lu\n",
1684 			sbi->s_frags_per_group);
1685 		goto failed_mount;
1686 	}
1687 	if (sbi->s_inodes_per_group > blocksize * 8) {
1688 		printk (KERN_ERR
1689 			"EXT4-fs: #inodes per group too big: %lu\n",
1690 			sbi->s_inodes_per_group);
1691 		goto failed_mount;
1692 	}
1693 
1694 	if (ext4_blocks_count(es) >
1695 		    (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1696 		printk(KERN_ERR "EXT4-fs: filesystem on %s:"
1697 			" too large to mount safely\n", sb->s_id);
1698 		if (sizeof(sector_t) < 8)
1699 			printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
1700 					"enabled\n");
1701 		goto failed_mount;
1702 	}
1703 
1704 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
1705 		goto cantfind_ext4;
1706 	blocks_count = (ext4_blocks_count(es) -
1707 			le32_to_cpu(es->s_first_data_block) +
1708 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
1709 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
1710 	sbi->s_groups_count = blocks_count;
1711 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
1712 		   EXT4_DESC_PER_BLOCK(sb);
1713 	sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
1714 				    GFP_KERNEL);
1715 	if (sbi->s_group_desc == NULL) {
1716 		printk (KERN_ERR "EXT4-fs: not enough memory\n");
1717 		goto failed_mount;
1718 	}
1719 
1720 	bgl_lock_init(&sbi->s_blockgroup_lock);
1721 
1722 	for (i = 0; i < db_count; i++) {
1723 		block = descriptor_loc(sb, logical_sb_block, i);
1724 		sbi->s_group_desc[i] = sb_bread(sb, block);
1725 		if (!sbi->s_group_desc[i]) {
1726 			printk (KERN_ERR "EXT4-fs: "
1727 				"can't read group descriptor %d\n", i);
1728 			db_count = i;
1729 			goto failed_mount2;
1730 		}
1731 	}
1732 	if (!ext4_check_descriptors (sb)) {
1733 		printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
1734 		goto failed_mount2;
1735 	}
1736 	sbi->s_gdb_count = db_count;
1737 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1738 	spin_lock_init(&sbi->s_next_gen_lock);
1739 
1740 	percpu_counter_init(&sbi->s_freeblocks_counter,
1741 		ext4_count_free_blocks(sb));
1742 	percpu_counter_init(&sbi->s_freeinodes_counter,
1743 		ext4_count_free_inodes(sb));
1744 	percpu_counter_init(&sbi->s_dirs_counter,
1745 		ext4_count_dirs(sb));
1746 
1747 	/* per fileystem reservation list head & lock */
1748 	spin_lock_init(&sbi->s_rsv_window_lock);
1749 	sbi->s_rsv_window_root = RB_ROOT;
1750 	/* Add a single, static dummy reservation to the start of the
1751 	 * reservation window list --- it gives us a placeholder for
1752 	 * append-at-start-of-list which makes the allocation logic
1753 	 * _much_ simpler. */
1754 	sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1755 	sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1756 	sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1757 	sbi->s_rsv_window_head.rsv_goal_size = 0;
1758 	ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
1759 
1760 	/*
1761 	 * set up enough so that it can read an inode
1762 	 */
1763 	sb->s_op = &ext4_sops;
1764 	sb->s_export_op = &ext4_export_ops;
1765 	sb->s_xattr = ext4_xattr_handlers;
1766 #ifdef CONFIG_QUOTA
1767 	sb->s_qcop = &ext4_qctl_operations;
1768 	sb->dq_op = &ext4_quota_operations;
1769 #endif
1770 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
1771 
1772 	sb->s_root = NULL;
1773 
1774 	needs_recovery = (es->s_last_orphan != 0 ||
1775 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
1776 				    EXT4_FEATURE_INCOMPAT_RECOVER));
1777 
1778 	/*
1779 	 * The first inode we look at is the journal inode.  Don't try
1780 	 * root first: it may be modified in the journal!
1781 	 */
1782 	if (!test_opt(sb, NOLOAD) &&
1783 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
1784 		if (ext4_load_journal(sb, es, journal_devnum))
1785 			goto failed_mount3;
1786 	} else if (journal_inum) {
1787 		if (ext4_create_journal(sb, es, journal_inum))
1788 			goto failed_mount3;
1789 	} else {
1790 		if (!silent)
1791 			printk (KERN_ERR
1792 				"ext4: No journal on filesystem on %s\n",
1793 				sb->s_id);
1794 		goto failed_mount3;
1795 	}
1796 
1797 	/* We have now updated the journal if required, so we can
1798 	 * validate the data journaling mode. */
1799 	switch (test_opt(sb, DATA_FLAGS)) {
1800 	case 0:
1801 		/* No mode set, assume a default based on the journal
1802 		 * capabilities: ORDERED_DATA if the journal can
1803 		 * cope, else JOURNAL_DATA
1804 		 */
1805 		if (jbd2_journal_check_available_features
1806 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
1807 			set_opt(sbi->s_mount_opt, ORDERED_DATA);
1808 		else
1809 			set_opt(sbi->s_mount_opt, JOURNAL_DATA);
1810 		break;
1811 
1812 	case EXT4_MOUNT_ORDERED_DATA:
1813 	case EXT4_MOUNT_WRITEBACK_DATA:
1814 		if (!jbd2_journal_check_available_features
1815 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
1816 			printk(KERN_ERR "EXT4-fs: Journal does not support "
1817 			       "requested data journaling mode\n");
1818 			goto failed_mount4;
1819 		}
1820 	default:
1821 		break;
1822 	}
1823 
1824 	if (test_opt(sb, NOBH)) {
1825 		if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
1826 			printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
1827 				"its supported only with writeback mode\n");
1828 			clear_opt(sbi->s_mount_opt, NOBH);
1829 		}
1830 	}
1831 	/*
1832 	 * The jbd2_journal_load will have done any necessary log recovery,
1833 	 * so we can safely mount the rest of the filesystem now.
1834 	 */
1835 
1836 	root = iget(sb, EXT4_ROOT_INO);
1837 	sb->s_root = d_alloc_root(root);
1838 	if (!sb->s_root) {
1839 		printk(KERN_ERR "EXT4-fs: get root inode failed\n");
1840 		iput(root);
1841 		goto failed_mount4;
1842 	}
1843 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1844 		dput(sb->s_root);
1845 		sb->s_root = NULL;
1846 		printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
1847 		goto failed_mount4;
1848 	}
1849 
1850 	ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1851 	/*
1852 	 * akpm: core read_super() calls in here with the superblock locked.
1853 	 * That deadlocks, because orphan cleanup needs to lock the superblock
1854 	 * in numerous places.  Here we just pop the lock - it's relatively
1855 	 * harmless, because we are now ready to accept write_super() requests,
1856 	 * and aviro says that's the only reason for hanging onto the
1857 	 * superblock lock.
1858 	 */
1859 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
1860 	ext4_orphan_cleanup(sb, es);
1861 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
1862 	if (needs_recovery)
1863 		printk (KERN_INFO "EXT4-fs: recovery complete.\n");
1864 	ext4_mark_recovery_complete(sb, es);
1865 	printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
1866 		test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
1867 		test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
1868 		"writeback");
1869 
1870 	ext4_ext_init(sb);
1871 
1872 	lock_kernel();
1873 	return 0;
1874 
1875 cantfind_ext4:
1876 	if (!silent)
1877 		printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
1878 		       sb->s_id);
1879 	goto failed_mount;
1880 
1881 failed_mount4:
1882 	jbd2_journal_destroy(sbi->s_journal);
1883 failed_mount3:
1884 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
1885 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1886 	percpu_counter_destroy(&sbi->s_dirs_counter);
1887 failed_mount2:
1888 	for (i = 0; i < db_count; i++)
1889 		brelse(sbi->s_group_desc[i]);
1890 	kfree(sbi->s_group_desc);
1891 failed_mount:
1892 #ifdef CONFIG_QUOTA
1893 	for (i = 0; i < MAXQUOTAS; i++)
1894 		kfree(sbi->s_qf_names[i]);
1895 #endif
1896 	ext4_blkdev_remove(sbi);
1897 	brelse(bh);
1898 out_fail:
1899 	sb->s_fs_info = NULL;
1900 	kfree(sbi);
1901 	lock_kernel();
1902 	return -EINVAL;
1903 }
1904 
1905 /*
1906  * Setup any per-fs journal parameters now.  We'll do this both on
1907  * initial mount, once the journal has been initialised but before we've
1908  * done any recovery; and again on any subsequent remount.
1909  */
1910 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
1911 {
1912 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1913 
1914 	if (sbi->s_commit_interval)
1915 		journal->j_commit_interval = sbi->s_commit_interval;
1916 	/* We could also set up an ext4-specific default for the commit
1917 	 * interval here, but for now we'll just fall back to the jbd
1918 	 * default. */
1919 
1920 	spin_lock(&journal->j_state_lock);
1921 	if (test_opt(sb, BARRIER))
1922 		journal->j_flags |= JBD2_BARRIER;
1923 	else
1924 		journal->j_flags &= ~JBD2_BARRIER;
1925 	spin_unlock(&journal->j_state_lock);
1926 }
1927 
1928 static journal_t *ext4_get_journal(struct super_block *sb,
1929 				   unsigned int journal_inum)
1930 {
1931 	struct inode *journal_inode;
1932 	journal_t *journal;
1933 
1934 	/* First, test for the existence of a valid inode on disk.  Bad
1935 	 * things happen if we iget() an unused inode, as the subsequent
1936 	 * iput() will try to delete it. */
1937 
1938 	journal_inode = iget(sb, journal_inum);
1939 	if (!journal_inode) {
1940 		printk(KERN_ERR "EXT4-fs: no journal found.\n");
1941 		return NULL;
1942 	}
1943 	if (!journal_inode->i_nlink) {
1944 		make_bad_inode(journal_inode);
1945 		iput(journal_inode);
1946 		printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
1947 		return NULL;
1948 	}
1949 
1950 	jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
1951 		  journal_inode, journal_inode->i_size);
1952 	if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
1953 		printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
1954 		iput(journal_inode);
1955 		return NULL;
1956 	}
1957 
1958 	journal = jbd2_journal_init_inode(journal_inode);
1959 	if (!journal) {
1960 		printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
1961 		iput(journal_inode);
1962 		return NULL;
1963 	}
1964 	journal->j_private = sb;
1965 	ext4_init_journal_params(sb, journal);
1966 	return journal;
1967 }
1968 
1969 static journal_t *ext4_get_dev_journal(struct super_block *sb,
1970 				       dev_t j_dev)
1971 {
1972 	struct buffer_head * bh;
1973 	journal_t *journal;
1974 	ext4_fsblk_t start;
1975 	ext4_fsblk_t len;
1976 	int hblock, blocksize;
1977 	ext4_fsblk_t sb_block;
1978 	unsigned long offset;
1979 	struct ext4_super_block * es;
1980 	struct block_device *bdev;
1981 
1982 	bdev = ext4_blkdev_get(j_dev);
1983 	if (bdev == NULL)
1984 		return NULL;
1985 
1986 	if (bd_claim(bdev, sb)) {
1987 		printk(KERN_ERR
1988 			"EXT4: failed to claim external journal device.\n");
1989 		blkdev_put(bdev);
1990 		return NULL;
1991 	}
1992 
1993 	blocksize = sb->s_blocksize;
1994 	hblock = bdev_hardsect_size(bdev);
1995 	if (blocksize < hblock) {
1996 		printk(KERN_ERR
1997 			"EXT4-fs: blocksize too small for journal device.\n");
1998 		goto out_bdev;
1999 	}
2000 
2001 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2002 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2003 	set_blocksize(bdev, blocksize);
2004 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
2005 		printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2006 		       "external journal\n");
2007 		goto out_bdev;
2008 	}
2009 
2010 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2011 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2012 	    !(le32_to_cpu(es->s_feature_incompat) &
2013 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2014 		printk(KERN_ERR "EXT4-fs: external journal has "
2015 					"bad superblock\n");
2016 		brelse(bh);
2017 		goto out_bdev;
2018 	}
2019 
2020 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2021 		printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2022 		brelse(bh);
2023 		goto out_bdev;
2024 	}
2025 
2026 	len = ext4_blocks_count(es);
2027 	start = sb_block + 1;
2028 	brelse(bh);	/* we're done with the superblock */
2029 
2030 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2031 					start, len, blocksize);
2032 	if (!journal) {
2033 		printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2034 		goto out_bdev;
2035 	}
2036 	journal->j_private = sb;
2037 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
2038 	wait_on_buffer(journal->j_sb_buffer);
2039 	if (!buffer_uptodate(journal->j_sb_buffer)) {
2040 		printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2041 		goto out_journal;
2042 	}
2043 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2044 		printk(KERN_ERR "EXT4-fs: External journal has more than one "
2045 					"user (unsupported) - %d\n",
2046 			be32_to_cpu(journal->j_superblock->s_nr_users));
2047 		goto out_journal;
2048 	}
2049 	EXT4_SB(sb)->journal_bdev = bdev;
2050 	ext4_init_journal_params(sb, journal);
2051 	return journal;
2052 out_journal:
2053 	jbd2_journal_destroy(journal);
2054 out_bdev:
2055 	ext4_blkdev_put(bdev);
2056 	return NULL;
2057 }
2058 
2059 static int ext4_load_journal(struct super_block *sb,
2060 			     struct ext4_super_block *es,
2061 			     unsigned long journal_devnum)
2062 {
2063 	journal_t *journal;
2064 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2065 	dev_t journal_dev;
2066 	int err = 0;
2067 	int really_read_only;
2068 
2069 	if (journal_devnum &&
2070 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2071 		printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2072 			"numbers have changed\n");
2073 		journal_dev = new_decode_dev(journal_devnum);
2074 	} else
2075 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2076 
2077 	really_read_only = bdev_read_only(sb->s_bdev);
2078 
2079 	/*
2080 	 * Are we loading a blank journal or performing recovery after a
2081 	 * crash?  For recovery, we need to check in advance whether we
2082 	 * can get read-write access to the device.
2083 	 */
2084 
2085 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2086 		if (sb->s_flags & MS_RDONLY) {
2087 			printk(KERN_INFO "EXT4-fs: INFO: recovery "
2088 					"required on readonly filesystem.\n");
2089 			if (really_read_only) {
2090 				printk(KERN_ERR "EXT4-fs: write access "
2091 					"unavailable, cannot proceed.\n");
2092 				return -EROFS;
2093 			}
2094 			printk (KERN_INFO "EXT4-fs: write access will "
2095 					"be enabled during recovery.\n");
2096 		}
2097 	}
2098 
2099 	if (journal_inum && journal_dev) {
2100 		printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2101 		       "and inode journals!\n");
2102 		return -EINVAL;
2103 	}
2104 
2105 	if (journal_inum) {
2106 		if (!(journal = ext4_get_journal(sb, journal_inum)))
2107 			return -EINVAL;
2108 	} else {
2109 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2110 			return -EINVAL;
2111 	}
2112 
2113 	if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2114 		err = jbd2_journal_update_format(journal);
2115 		if (err)  {
2116 			printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2117 			jbd2_journal_destroy(journal);
2118 			return err;
2119 		}
2120 	}
2121 
2122 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2123 		err = jbd2_journal_wipe(journal, !really_read_only);
2124 	if (!err)
2125 		err = jbd2_journal_load(journal);
2126 
2127 	if (err) {
2128 		printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2129 		jbd2_journal_destroy(journal);
2130 		return err;
2131 	}
2132 
2133 	EXT4_SB(sb)->s_journal = journal;
2134 	ext4_clear_journal_err(sb, es);
2135 
2136 	if (journal_devnum &&
2137 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2138 		es->s_journal_dev = cpu_to_le32(journal_devnum);
2139 		sb->s_dirt = 1;
2140 
2141 		/* Make sure we flush the recovery flag to disk. */
2142 		ext4_commit_super(sb, es, 1);
2143 	}
2144 
2145 	return 0;
2146 }
2147 
2148 static int ext4_create_journal(struct super_block * sb,
2149 			       struct ext4_super_block * es,
2150 			       unsigned int journal_inum)
2151 {
2152 	journal_t *journal;
2153 
2154 	if (sb->s_flags & MS_RDONLY) {
2155 		printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2156 				"create journal.\n");
2157 		return -EROFS;
2158 	}
2159 
2160 	if (!(journal = ext4_get_journal(sb, journal_inum)))
2161 		return -EINVAL;
2162 
2163 	printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2164 	       journal_inum);
2165 
2166 	if (jbd2_journal_create(journal)) {
2167 		printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2168 		jbd2_journal_destroy(journal);
2169 		return -EIO;
2170 	}
2171 
2172 	EXT4_SB(sb)->s_journal = journal;
2173 
2174 	ext4_update_dynamic_rev(sb);
2175 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2176 	EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2177 
2178 	es->s_journal_inum = cpu_to_le32(journal_inum);
2179 	sb->s_dirt = 1;
2180 
2181 	/* Make sure we flush the recovery flag to disk. */
2182 	ext4_commit_super(sb, es, 1);
2183 
2184 	return 0;
2185 }
2186 
2187 static void ext4_commit_super (struct super_block * sb,
2188 			       struct ext4_super_block * es,
2189 			       int sync)
2190 {
2191 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2192 
2193 	if (!sbh)
2194 		return;
2195 	es->s_wtime = cpu_to_le32(get_seconds());
2196 	ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2197 	es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2198 	BUFFER_TRACE(sbh, "marking dirty");
2199 	mark_buffer_dirty(sbh);
2200 	if (sync)
2201 		sync_dirty_buffer(sbh);
2202 }
2203 
2204 
2205 /*
2206  * Have we just finished recovery?  If so, and if we are mounting (or
2207  * remounting) the filesystem readonly, then we will end up with a
2208  * consistent fs on disk.  Record that fact.
2209  */
2210 static void ext4_mark_recovery_complete(struct super_block * sb,
2211 					struct ext4_super_block * es)
2212 {
2213 	journal_t *journal = EXT4_SB(sb)->s_journal;
2214 
2215 	jbd2_journal_lock_updates(journal);
2216 	jbd2_journal_flush(journal);
2217 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2218 	    sb->s_flags & MS_RDONLY) {
2219 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2220 		sb->s_dirt = 0;
2221 		ext4_commit_super(sb, es, 1);
2222 	}
2223 	jbd2_journal_unlock_updates(journal);
2224 }
2225 
2226 /*
2227  * If we are mounting (or read-write remounting) a filesystem whose journal
2228  * has recorded an error from a previous lifetime, move that error to the
2229  * main filesystem now.
2230  */
2231 static void ext4_clear_journal_err(struct super_block * sb,
2232 				   struct ext4_super_block * es)
2233 {
2234 	journal_t *journal;
2235 	int j_errno;
2236 	const char *errstr;
2237 
2238 	journal = EXT4_SB(sb)->s_journal;
2239 
2240 	/*
2241 	 * Now check for any error status which may have been recorded in the
2242 	 * journal by a prior ext4_error() or ext4_abort()
2243 	 */
2244 
2245 	j_errno = jbd2_journal_errno(journal);
2246 	if (j_errno) {
2247 		char nbuf[16];
2248 
2249 		errstr = ext4_decode_error(sb, j_errno, nbuf);
2250 		ext4_warning(sb, __FUNCTION__, "Filesystem error recorded "
2251 			     "from previous mount: %s", errstr);
2252 		ext4_warning(sb, __FUNCTION__, "Marking fs in need of "
2253 			     "filesystem check.");
2254 
2255 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2256 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2257 		ext4_commit_super (sb, es, 1);
2258 
2259 		jbd2_journal_clear_err(journal);
2260 	}
2261 }
2262 
2263 /*
2264  * Force the running and committing transactions to commit,
2265  * and wait on the commit.
2266  */
2267 int ext4_force_commit(struct super_block *sb)
2268 {
2269 	journal_t *journal;
2270 	int ret;
2271 
2272 	if (sb->s_flags & MS_RDONLY)
2273 		return 0;
2274 
2275 	journal = EXT4_SB(sb)->s_journal;
2276 	sb->s_dirt = 0;
2277 	ret = ext4_journal_force_commit(journal);
2278 	return ret;
2279 }
2280 
2281 /*
2282  * Ext4 always journals updates to the superblock itself, so we don't
2283  * have to propagate any other updates to the superblock on disk at this
2284  * point.  Just start an async writeback to get the buffers on their way
2285  * to the disk.
2286  *
2287  * This implicitly triggers the writebehind on sync().
2288  */
2289 
2290 static void ext4_write_super (struct super_block * sb)
2291 {
2292 	if (mutex_trylock(&sb->s_lock) != 0)
2293 		BUG();
2294 	sb->s_dirt = 0;
2295 }
2296 
2297 static int ext4_sync_fs(struct super_block *sb, int wait)
2298 {
2299 	tid_t target;
2300 
2301 	sb->s_dirt = 0;
2302 	if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2303 		if (wait)
2304 			jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2305 	}
2306 	return 0;
2307 }
2308 
2309 /*
2310  * LVM calls this function before a (read-only) snapshot is created.  This
2311  * gives us a chance to flush the journal completely and mark the fs clean.
2312  */
2313 static void ext4_write_super_lockfs(struct super_block *sb)
2314 {
2315 	sb->s_dirt = 0;
2316 
2317 	if (!(sb->s_flags & MS_RDONLY)) {
2318 		journal_t *journal = EXT4_SB(sb)->s_journal;
2319 
2320 		/* Now we set up the journal barrier. */
2321 		jbd2_journal_lock_updates(journal);
2322 		jbd2_journal_flush(journal);
2323 
2324 		/* Journal blocked and flushed, clear needs_recovery flag. */
2325 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2326 		ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2327 	}
2328 }
2329 
2330 /*
2331  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2332  * flag here, even though the filesystem is not technically dirty yet.
2333  */
2334 static void ext4_unlockfs(struct super_block *sb)
2335 {
2336 	if (!(sb->s_flags & MS_RDONLY)) {
2337 		lock_super(sb);
2338 		/* Reser the needs_recovery flag before the fs is unlocked. */
2339 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2340 		ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2341 		unlock_super(sb);
2342 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2343 	}
2344 }
2345 
2346 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2347 {
2348 	struct ext4_super_block * es;
2349 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2350 	ext4_fsblk_t n_blocks_count = 0;
2351 	unsigned long old_sb_flags;
2352 	struct ext4_mount_options old_opts;
2353 	int err;
2354 #ifdef CONFIG_QUOTA
2355 	int i;
2356 #endif
2357 
2358 	/* Store the original options */
2359 	old_sb_flags = sb->s_flags;
2360 	old_opts.s_mount_opt = sbi->s_mount_opt;
2361 	old_opts.s_resuid = sbi->s_resuid;
2362 	old_opts.s_resgid = sbi->s_resgid;
2363 	old_opts.s_commit_interval = sbi->s_commit_interval;
2364 #ifdef CONFIG_QUOTA
2365 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2366 	for (i = 0; i < MAXQUOTAS; i++)
2367 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2368 #endif
2369 
2370 	/*
2371 	 * Allow the "check" option to be passed as a remount option.
2372 	 */
2373 	if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2374 		err = -EINVAL;
2375 		goto restore_opts;
2376 	}
2377 
2378 	if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2379 		ext4_abort(sb, __FUNCTION__, "Abort forced by user");
2380 
2381 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2382 		((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2383 
2384 	es = sbi->s_es;
2385 
2386 	ext4_init_journal_params(sb, sbi->s_journal);
2387 
2388 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2389 		n_blocks_count > ext4_blocks_count(es)) {
2390 		if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2391 			err = -EROFS;
2392 			goto restore_opts;
2393 		}
2394 
2395 		if (*flags & MS_RDONLY) {
2396 			/*
2397 			 * First of all, the unconditional stuff we have to do
2398 			 * to disable replay of the journal when we next remount
2399 			 */
2400 			sb->s_flags |= MS_RDONLY;
2401 
2402 			/*
2403 			 * OK, test if we are remounting a valid rw partition
2404 			 * readonly, and if so set the rdonly flag and then
2405 			 * mark the partition as valid again.
2406 			 */
2407 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2408 			    (sbi->s_mount_state & EXT4_VALID_FS))
2409 				es->s_state = cpu_to_le16(sbi->s_mount_state);
2410 
2411 			ext4_mark_recovery_complete(sb, es);
2412 		} else {
2413 			__le32 ret;
2414 			if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2415 					~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2416 				printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2417 				       "remount RDWR because of unsupported "
2418 				       "optional features (%x).\n",
2419 				       sb->s_id, le32_to_cpu(ret));
2420 				err = -EROFS;
2421 				goto restore_opts;
2422 			}
2423 
2424 			/*
2425 			 * If we have an unprocessed orphan list hanging
2426 			 * around from a previously readonly bdev mount,
2427 			 * require a full umount/remount for now.
2428 			 */
2429 			if (es->s_last_orphan) {
2430 				printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2431 				       "remount RDWR because of unprocessed "
2432 				       "orphan inode list.  Please "
2433 				       "umount/remount instead.\n",
2434 				       sb->s_id);
2435 				err = -EINVAL;
2436 				goto restore_opts;
2437 			}
2438 
2439 			/*
2440 			 * Mounting a RDONLY partition read-write, so reread
2441 			 * and store the current valid flag.  (It may have
2442 			 * been changed by e2fsck since we originally mounted
2443 			 * the partition.)
2444 			 */
2445 			ext4_clear_journal_err(sb, es);
2446 			sbi->s_mount_state = le16_to_cpu(es->s_state);
2447 			if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2448 				goto restore_opts;
2449 			if (!ext4_setup_super (sb, es, 0))
2450 				sb->s_flags &= ~MS_RDONLY;
2451 		}
2452 	}
2453 #ifdef CONFIG_QUOTA
2454 	/* Release old quota file names */
2455 	for (i = 0; i < MAXQUOTAS; i++)
2456 		if (old_opts.s_qf_names[i] &&
2457 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2458 			kfree(old_opts.s_qf_names[i]);
2459 #endif
2460 	return 0;
2461 restore_opts:
2462 	sb->s_flags = old_sb_flags;
2463 	sbi->s_mount_opt = old_opts.s_mount_opt;
2464 	sbi->s_resuid = old_opts.s_resuid;
2465 	sbi->s_resgid = old_opts.s_resgid;
2466 	sbi->s_commit_interval = old_opts.s_commit_interval;
2467 #ifdef CONFIG_QUOTA
2468 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2469 	for (i = 0; i < MAXQUOTAS; i++) {
2470 		if (sbi->s_qf_names[i] &&
2471 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2472 			kfree(sbi->s_qf_names[i]);
2473 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2474 	}
2475 #endif
2476 	return err;
2477 }
2478 
2479 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2480 {
2481 	struct super_block *sb = dentry->d_sb;
2482 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2483 	struct ext4_super_block *es = sbi->s_es;
2484 	ext4_fsblk_t overhead;
2485 	int i;
2486 	u64 fsid;
2487 
2488 	if (test_opt (sb, MINIX_DF))
2489 		overhead = 0;
2490 	else {
2491 		unsigned long ngroups;
2492 		ngroups = EXT4_SB(sb)->s_groups_count;
2493 		smp_rmb();
2494 
2495 		/*
2496 		 * Compute the overhead (FS structures)
2497 		 */
2498 
2499 		/*
2500 		 * All of the blocks before first_data_block are
2501 		 * overhead
2502 		 */
2503 		overhead = le32_to_cpu(es->s_first_data_block);
2504 
2505 		/*
2506 		 * Add the overhead attributed to the superblock and
2507 		 * block group descriptors.  If the sparse superblocks
2508 		 * feature is turned on, then not all groups have this.
2509 		 */
2510 		for (i = 0; i < ngroups; i++) {
2511 			overhead += ext4_bg_has_super(sb, i) +
2512 				ext4_bg_num_gdb(sb, i);
2513 			cond_resched();
2514 		}
2515 
2516 		/*
2517 		 * Every block group has an inode bitmap, a block
2518 		 * bitmap, and an inode table.
2519 		 */
2520 		overhead += (ngroups * (2 + EXT4_SB(sb)->s_itb_per_group));
2521 	}
2522 
2523 	buf->f_type = EXT4_SUPER_MAGIC;
2524 	buf->f_bsize = sb->s_blocksize;
2525 	buf->f_blocks = ext4_blocks_count(es) - overhead;
2526 	buf->f_bfree = percpu_counter_sum(&sbi->s_freeblocks_counter);
2527 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2528 	if (buf->f_bfree < ext4_r_blocks_count(es))
2529 		buf->f_bavail = 0;
2530 	buf->f_files = le32_to_cpu(es->s_inodes_count);
2531 	buf->f_ffree = percpu_counter_sum(&sbi->s_freeinodes_counter);
2532 	buf->f_namelen = EXT4_NAME_LEN;
2533 	fsid = le64_to_cpup((void *)es->s_uuid) ^
2534 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2535 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2536 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2537 	return 0;
2538 }
2539 
2540 /* Helper function for writing quotas on sync - we need to start transaction before quota file
2541  * is locked for write. Otherwise the are possible deadlocks:
2542  * Process 1                         Process 2
2543  * ext4_create()                     quota_sync()
2544  *   jbd2_journal_start()                   write_dquot()
2545  *   DQUOT_INIT()                        down(dqio_mutex)
2546  *     down(dqio_mutex)                    jbd2_journal_start()
2547  *
2548  */
2549 
2550 #ifdef CONFIG_QUOTA
2551 
2552 static inline struct inode *dquot_to_inode(struct dquot *dquot)
2553 {
2554 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
2555 }
2556 
2557 static int ext4_dquot_initialize(struct inode *inode, int type)
2558 {
2559 	handle_t *handle;
2560 	int ret, err;
2561 
2562 	/* We may create quota structure so we need to reserve enough blocks */
2563 	handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
2564 	if (IS_ERR(handle))
2565 		return PTR_ERR(handle);
2566 	ret = dquot_initialize(inode, type);
2567 	err = ext4_journal_stop(handle);
2568 	if (!ret)
2569 		ret = err;
2570 	return ret;
2571 }
2572 
2573 static int ext4_dquot_drop(struct inode *inode)
2574 {
2575 	handle_t *handle;
2576 	int ret, err;
2577 
2578 	/* We may delete quota structure so we need to reserve enough blocks */
2579 	handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
2580 	if (IS_ERR(handle))
2581 		return PTR_ERR(handle);
2582 	ret = dquot_drop(inode);
2583 	err = ext4_journal_stop(handle);
2584 	if (!ret)
2585 		ret = err;
2586 	return ret;
2587 }
2588 
2589 static int ext4_write_dquot(struct dquot *dquot)
2590 {
2591 	int ret, err;
2592 	handle_t *handle;
2593 	struct inode *inode;
2594 
2595 	inode = dquot_to_inode(dquot);
2596 	handle = ext4_journal_start(inode,
2597 					EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
2598 	if (IS_ERR(handle))
2599 		return PTR_ERR(handle);
2600 	ret = dquot_commit(dquot);
2601 	err = ext4_journal_stop(handle);
2602 	if (!ret)
2603 		ret = err;
2604 	return ret;
2605 }
2606 
2607 static int ext4_acquire_dquot(struct dquot *dquot)
2608 {
2609 	int ret, err;
2610 	handle_t *handle;
2611 
2612 	handle = ext4_journal_start(dquot_to_inode(dquot),
2613 					EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
2614 	if (IS_ERR(handle))
2615 		return PTR_ERR(handle);
2616 	ret = dquot_acquire(dquot);
2617 	err = ext4_journal_stop(handle);
2618 	if (!ret)
2619 		ret = err;
2620 	return ret;
2621 }
2622 
2623 static int ext4_release_dquot(struct dquot *dquot)
2624 {
2625 	int ret, err;
2626 	handle_t *handle;
2627 
2628 	handle = ext4_journal_start(dquot_to_inode(dquot),
2629 					EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
2630 	if (IS_ERR(handle))
2631 		return PTR_ERR(handle);
2632 	ret = dquot_release(dquot);
2633 	err = ext4_journal_stop(handle);
2634 	if (!ret)
2635 		ret = err;
2636 	return ret;
2637 }
2638 
2639 static int ext4_mark_dquot_dirty(struct dquot *dquot)
2640 {
2641 	/* Are we journalling quotas? */
2642 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
2643 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
2644 		dquot_mark_dquot_dirty(dquot);
2645 		return ext4_write_dquot(dquot);
2646 	} else {
2647 		return dquot_mark_dquot_dirty(dquot);
2648 	}
2649 }
2650 
2651 static int ext4_write_info(struct super_block *sb, int type)
2652 {
2653 	int ret, err;
2654 	handle_t *handle;
2655 
2656 	/* Data block + inode block */
2657 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
2658 	if (IS_ERR(handle))
2659 		return PTR_ERR(handle);
2660 	ret = dquot_commit_info(sb, type);
2661 	err = ext4_journal_stop(handle);
2662 	if (!ret)
2663 		ret = err;
2664 	return ret;
2665 }
2666 
2667 /*
2668  * Turn on quotas during mount time - we need to find
2669  * the quota file and such...
2670  */
2671 static int ext4_quota_on_mount(struct super_block *sb, int type)
2672 {
2673 	return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
2674 			EXT4_SB(sb)->s_jquota_fmt, type);
2675 }
2676 
2677 /*
2678  * Standard function to be called on quota_on
2679  */
2680 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
2681 			 char *path)
2682 {
2683 	int err;
2684 	struct nameidata nd;
2685 
2686 	if (!test_opt(sb, QUOTA))
2687 		return -EINVAL;
2688 	/* Not journalling quota? */
2689 	if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
2690 	    !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
2691 		return vfs_quota_on(sb, type, format_id, path);
2692 	err = path_lookup(path, LOOKUP_FOLLOW, &nd);
2693 	if (err)
2694 		return err;
2695 	/* Quotafile not on the same filesystem? */
2696 	if (nd.mnt->mnt_sb != sb) {
2697 		path_release(&nd);
2698 		return -EXDEV;
2699 	}
2700 	/* Quotafile not of fs root? */
2701 	if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
2702 		printk(KERN_WARNING
2703 			"EXT4-fs: Quota file not on filesystem root. "
2704 			"Journalled quota will not work.\n");
2705 	path_release(&nd);
2706 	return vfs_quota_on(sb, type, format_id, path);
2707 }
2708 
2709 /* Read data from quotafile - avoid pagecache and such because we cannot afford
2710  * acquiring the locks... As quota files are never truncated and quota code
2711  * itself serializes the operations (and noone else should touch the files)
2712  * we don't have to be afraid of races */
2713 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
2714 			       size_t len, loff_t off)
2715 {
2716 	struct inode *inode = sb_dqopt(sb)->files[type];
2717 	sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2718 	int err = 0;
2719 	int offset = off & (sb->s_blocksize - 1);
2720 	int tocopy;
2721 	size_t toread;
2722 	struct buffer_head *bh;
2723 	loff_t i_size = i_size_read(inode);
2724 
2725 	if (off > i_size)
2726 		return 0;
2727 	if (off+len > i_size)
2728 		len = i_size-off;
2729 	toread = len;
2730 	while (toread > 0) {
2731 		tocopy = sb->s_blocksize - offset < toread ?
2732 				sb->s_blocksize - offset : toread;
2733 		bh = ext4_bread(NULL, inode, blk, 0, &err);
2734 		if (err)
2735 			return err;
2736 		if (!bh)	/* A hole? */
2737 			memset(data, 0, tocopy);
2738 		else
2739 			memcpy(data, bh->b_data+offset, tocopy);
2740 		brelse(bh);
2741 		offset = 0;
2742 		toread -= tocopy;
2743 		data += tocopy;
2744 		blk++;
2745 	}
2746 	return len;
2747 }
2748 
2749 /* Write to quotafile (we know the transaction is already started and has
2750  * enough credits) */
2751 static ssize_t ext4_quota_write(struct super_block *sb, int type,
2752 				const char *data, size_t len, loff_t off)
2753 {
2754 	struct inode *inode = sb_dqopt(sb)->files[type];
2755 	sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2756 	int err = 0;
2757 	int offset = off & (sb->s_blocksize - 1);
2758 	int tocopy;
2759 	int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
2760 	size_t towrite = len;
2761 	struct buffer_head *bh;
2762 	handle_t *handle = journal_current_handle();
2763 
2764 	mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2765 	while (towrite > 0) {
2766 		tocopy = sb->s_blocksize - offset < towrite ?
2767 				sb->s_blocksize - offset : towrite;
2768 		bh = ext4_bread(handle, inode, blk, 1, &err);
2769 		if (!bh)
2770 			goto out;
2771 		if (journal_quota) {
2772 			err = ext4_journal_get_write_access(handle, bh);
2773 			if (err) {
2774 				brelse(bh);
2775 				goto out;
2776 			}
2777 		}
2778 		lock_buffer(bh);
2779 		memcpy(bh->b_data+offset, data, tocopy);
2780 		flush_dcache_page(bh->b_page);
2781 		unlock_buffer(bh);
2782 		if (journal_quota)
2783 			err = ext4_journal_dirty_metadata(handle, bh);
2784 		else {
2785 			/* Always do at least ordered writes for quotas */
2786 			err = ext4_journal_dirty_data(handle, bh);
2787 			mark_buffer_dirty(bh);
2788 		}
2789 		brelse(bh);
2790 		if (err)
2791 			goto out;
2792 		offset = 0;
2793 		towrite -= tocopy;
2794 		data += tocopy;
2795 		blk++;
2796 	}
2797 out:
2798 	if (len == towrite)
2799 		return err;
2800 	if (inode->i_size < off+len-towrite) {
2801 		i_size_write(inode, off+len-towrite);
2802 		EXT4_I(inode)->i_disksize = inode->i_size;
2803 	}
2804 	inode->i_version++;
2805 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2806 	ext4_mark_inode_dirty(handle, inode);
2807 	mutex_unlock(&inode->i_mutex);
2808 	return len - towrite;
2809 }
2810 
2811 #endif
2812 
2813 static int ext4_get_sb(struct file_system_type *fs_type,
2814 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
2815 {
2816 	return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
2817 }
2818 
2819 static struct file_system_type ext4dev_fs_type = {
2820 	.owner		= THIS_MODULE,
2821 	.name		= "ext4dev",
2822 	.get_sb		= ext4_get_sb,
2823 	.kill_sb	= kill_block_super,
2824 	.fs_flags	= FS_REQUIRES_DEV,
2825 };
2826 
2827 static int __init init_ext4_fs(void)
2828 {
2829 	int err = init_ext4_xattr();
2830 	if (err)
2831 		return err;
2832 	err = init_inodecache();
2833 	if (err)
2834 		goto out1;
2835 	err = register_filesystem(&ext4dev_fs_type);
2836 	if (err)
2837 		goto out;
2838 	return 0;
2839 out:
2840 	destroy_inodecache();
2841 out1:
2842 	exit_ext4_xattr();
2843 	return err;
2844 }
2845 
2846 static void __exit exit_ext4_fs(void)
2847 {
2848 	unregister_filesystem(&ext4dev_fs_type);
2849 	destroy_inodecache();
2850 	exit_ext4_xattr();
2851 }
2852 
2853 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
2854 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
2855 MODULE_LICENSE("GPL");
2856 module_init(init_ext4_fs)
2857 module_exit(exit_ext4_fs)
2858