xref: /openbmc/linux/fs/ext4/super.c (revision 5e70030d4cf91613530a23b40ad9919bb9ee114f)
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 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
514 		printk("EXT4 Inode %p: orphan list check failed!\n",
515 			EXT4_I(inode));
516 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
517 				EXT4_I(inode), sizeof(struct ext4_inode_info),
518 				true);
519 		dump_stack();
520 	}
521 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
522 }
523 
524 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
525 {
526 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
527 
528 	INIT_LIST_HEAD(&ei->i_orphan);
529 #ifdef CONFIG_EXT4DEV_FS_XATTR
530 	init_rwsem(&ei->xattr_sem);
531 #endif
532 	mutex_init(&ei->truncate_mutex);
533 	inode_init_once(&ei->vfs_inode);
534 }
535 
536 static int init_inodecache(void)
537 {
538 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
539 					     sizeof(struct ext4_inode_info),
540 					     0, (SLAB_RECLAIM_ACCOUNT|
541 						SLAB_MEM_SPREAD),
542 					     init_once, NULL);
543 	if (ext4_inode_cachep == NULL)
544 		return -ENOMEM;
545 	return 0;
546 }
547 
548 static void destroy_inodecache(void)
549 {
550 	kmem_cache_destroy(ext4_inode_cachep);
551 }
552 
553 static void ext4_clear_inode(struct inode *inode)
554 {
555 	struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
556 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
557 	if (EXT4_I(inode)->i_acl &&
558 			EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
559 		posix_acl_release(EXT4_I(inode)->i_acl);
560 		EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
561 	}
562 	if (EXT4_I(inode)->i_default_acl &&
563 			EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
564 		posix_acl_release(EXT4_I(inode)->i_default_acl);
565 		EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
566 	}
567 #endif
568 	ext4_discard_reservation(inode);
569 	EXT4_I(inode)->i_block_alloc_info = NULL;
570 	if (unlikely(rsv))
571 		kfree(rsv);
572 }
573 
574 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
575 {
576 #if defined(CONFIG_QUOTA)
577 	struct ext4_sb_info *sbi = EXT4_SB(sb);
578 
579 	if (sbi->s_jquota_fmt)
580 		seq_printf(seq, ",jqfmt=%s",
581 		(sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
582 
583 	if (sbi->s_qf_names[USRQUOTA])
584 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
585 
586 	if (sbi->s_qf_names[GRPQUOTA])
587 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
588 
589 	if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
590 		seq_puts(seq, ",usrquota");
591 
592 	if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
593 		seq_puts(seq, ",grpquota");
594 #endif
595 }
596 
597 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
598 {
599 	struct super_block *sb = vfs->mnt_sb;
600 
601 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
602 		seq_puts(seq, ",data=journal");
603 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
604 		seq_puts(seq, ",data=ordered");
605 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
606 		seq_puts(seq, ",data=writeback");
607 
608 	ext4_show_quota_options(seq, sb);
609 
610 	return 0;
611 }
612 
613 
614 static struct dentry *ext4_get_dentry(struct super_block *sb, void *vobjp)
615 {
616 	__u32 *objp = vobjp;
617 	unsigned long ino = objp[0];
618 	__u32 generation = objp[1];
619 	struct inode *inode;
620 	struct dentry *result;
621 
622 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
623 		return ERR_PTR(-ESTALE);
624 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
625 		return ERR_PTR(-ESTALE);
626 
627 	/* iget isn't really right if the inode is currently unallocated!!
628 	 *
629 	 * ext4_read_inode will return a bad_inode if the inode had been
630 	 * deleted, so we should be safe.
631 	 *
632 	 * Currently we don't know the generation for parent directory, so
633 	 * a generation of 0 means "accept any"
634 	 */
635 	inode = iget(sb, ino);
636 	if (inode == NULL)
637 		return ERR_PTR(-ENOMEM);
638 	if (is_bad_inode(inode) ||
639 	    (generation && inode->i_generation != generation)) {
640 		iput(inode);
641 		return ERR_PTR(-ESTALE);
642 	}
643 	/* now to find a dentry.
644 	 * If possible, get a well-connected one
645 	 */
646 	result = d_alloc_anon(inode);
647 	if (!result) {
648 		iput(inode);
649 		return ERR_PTR(-ENOMEM);
650 	}
651 	return result;
652 }
653 
654 #ifdef CONFIG_QUOTA
655 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
656 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
657 
658 static int ext4_dquot_initialize(struct inode *inode, int type);
659 static int ext4_dquot_drop(struct inode *inode);
660 static int ext4_write_dquot(struct dquot *dquot);
661 static int ext4_acquire_dquot(struct dquot *dquot);
662 static int ext4_release_dquot(struct dquot *dquot);
663 static int ext4_mark_dquot_dirty(struct dquot *dquot);
664 static int ext4_write_info(struct super_block *sb, int type);
665 static int ext4_quota_on(struct super_block *sb, int type, int format_id, char *path);
666 static int ext4_quota_on_mount(struct super_block *sb, int type);
667 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
668 			       size_t len, loff_t off);
669 static ssize_t ext4_quota_write(struct super_block *sb, int type,
670 				const char *data, size_t len, loff_t off);
671 
672 static struct dquot_operations ext4_quota_operations = {
673 	.initialize	= ext4_dquot_initialize,
674 	.drop		= ext4_dquot_drop,
675 	.alloc_space	= dquot_alloc_space,
676 	.alloc_inode	= dquot_alloc_inode,
677 	.free_space	= dquot_free_space,
678 	.free_inode	= dquot_free_inode,
679 	.transfer	= dquot_transfer,
680 	.write_dquot	= ext4_write_dquot,
681 	.acquire_dquot	= ext4_acquire_dquot,
682 	.release_dquot	= ext4_release_dquot,
683 	.mark_dirty	= ext4_mark_dquot_dirty,
684 	.write_info	= ext4_write_info
685 };
686 
687 static struct quotactl_ops ext4_qctl_operations = {
688 	.quota_on	= ext4_quota_on,
689 	.quota_off	= vfs_quota_off,
690 	.quota_sync	= vfs_quota_sync,
691 	.get_info	= vfs_get_dqinfo,
692 	.set_info	= vfs_set_dqinfo,
693 	.get_dqblk	= vfs_get_dqblk,
694 	.set_dqblk	= vfs_set_dqblk
695 };
696 #endif
697 
698 static const struct super_operations ext4_sops = {
699 	.alloc_inode	= ext4_alloc_inode,
700 	.destroy_inode	= ext4_destroy_inode,
701 	.read_inode	= ext4_read_inode,
702 	.write_inode	= ext4_write_inode,
703 	.dirty_inode	= ext4_dirty_inode,
704 	.delete_inode	= ext4_delete_inode,
705 	.put_super	= ext4_put_super,
706 	.write_super	= ext4_write_super,
707 	.sync_fs	= ext4_sync_fs,
708 	.write_super_lockfs = ext4_write_super_lockfs,
709 	.unlockfs	= ext4_unlockfs,
710 	.statfs		= ext4_statfs,
711 	.remount_fs	= ext4_remount,
712 	.clear_inode	= ext4_clear_inode,
713 	.show_options	= ext4_show_options,
714 #ifdef CONFIG_QUOTA
715 	.quota_read	= ext4_quota_read,
716 	.quota_write	= ext4_quota_write,
717 #endif
718 };
719 
720 static struct export_operations ext4_export_ops = {
721 	.get_parent = ext4_get_parent,
722 	.get_dentry = ext4_get_dentry,
723 };
724 
725 enum {
726 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
727 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
728 	Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
729 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
730 	Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
731 	Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
732 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
733 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
734 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
735 	Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
736 	Opt_grpquota, Opt_extents,
737 };
738 
739 static match_table_t tokens = {
740 	{Opt_bsd_df, "bsddf"},
741 	{Opt_minix_df, "minixdf"},
742 	{Opt_grpid, "grpid"},
743 	{Opt_grpid, "bsdgroups"},
744 	{Opt_nogrpid, "nogrpid"},
745 	{Opt_nogrpid, "sysvgroups"},
746 	{Opt_resgid, "resgid=%u"},
747 	{Opt_resuid, "resuid=%u"},
748 	{Opt_sb, "sb=%u"},
749 	{Opt_err_cont, "errors=continue"},
750 	{Opt_err_panic, "errors=panic"},
751 	{Opt_err_ro, "errors=remount-ro"},
752 	{Opt_nouid32, "nouid32"},
753 	{Opt_nocheck, "nocheck"},
754 	{Opt_nocheck, "check=none"},
755 	{Opt_debug, "debug"},
756 	{Opt_oldalloc, "oldalloc"},
757 	{Opt_orlov, "orlov"},
758 	{Opt_user_xattr, "user_xattr"},
759 	{Opt_nouser_xattr, "nouser_xattr"},
760 	{Opt_acl, "acl"},
761 	{Opt_noacl, "noacl"},
762 	{Opt_reservation, "reservation"},
763 	{Opt_noreservation, "noreservation"},
764 	{Opt_noload, "noload"},
765 	{Opt_nobh, "nobh"},
766 	{Opt_bh, "bh"},
767 	{Opt_commit, "commit=%u"},
768 	{Opt_journal_update, "journal=update"},
769 	{Opt_journal_inum, "journal=%u"},
770 	{Opt_journal_dev, "journal_dev=%u"},
771 	{Opt_abort, "abort"},
772 	{Opt_data_journal, "data=journal"},
773 	{Opt_data_ordered, "data=ordered"},
774 	{Opt_data_writeback, "data=writeback"},
775 	{Opt_offusrjquota, "usrjquota="},
776 	{Opt_usrjquota, "usrjquota=%s"},
777 	{Opt_offgrpjquota, "grpjquota="},
778 	{Opt_grpjquota, "grpjquota=%s"},
779 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
780 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
781 	{Opt_grpquota, "grpquota"},
782 	{Opt_noquota, "noquota"},
783 	{Opt_quota, "quota"},
784 	{Opt_usrquota, "usrquota"},
785 	{Opt_barrier, "barrier=%u"},
786 	{Opt_extents, "extents"},
787 	{Opt_err, NULL},
788 	{Opt_resize, "resize"},
789 };
790 
791 static ext4_fsblk_t get_sb_block(void **data)
792 {
793 	ext4_fsblk_t	sb_block;
794 	char		*options = (char *) *data;
795 
796 	if (!options || strncmp(options, "sb=", 3) != 0)
797 		return 1;	/* Default location */
798 	options += 3;
799 	/*todo: use simple_strtoll with >32bit ext4 */
800 	sb_block = simple_strtoul(options, &options, 0);
801 	if (*options && *options != ',') {
802 		printk("EXT4-fs: Invalid sb specification: %s\n",
803 		       (char *) *data);
804 		return 1;
805 	}
806 	if (*options == ',')
807 		options++;
808 	*data = (void *) options;
809 	return sb_block;
810 }
811 
812 static int parse_options (char *options, struct super_block *sb,
813 			  unsigned int *inum, unsigned long *journal_devnum,
814 			  ext4_fsblk_t *n_blocks_count, int is_remount)
815 {
816 	struct ext4_sb_info *sbi = EXT4_SB(sb);
817 	char * p;
818 	substring_t args[MAX_OPT_ARGS];
819 	int data_opt = 0;
820 	int option;
821 #ifdef CONFIG_QUOTA
822 	int qtype;
823 	char *qname;
824 #endif
825 
826 	if (!options)
827 		return 1;
828 
829 	while ((p = strsep (&options, ",")) != NULL) {
830 		int token;
831 		if (!*p)
832 			continue;
833 
834 		token = match_token(p, tokens, args);
835 		switch (token) {
836 		case Opt_bsd_df:
837 			clear_opt (sbi->s_mount_opt, MINIX_DF);
838 			break;
839 		case Opt_minix_df:
840 			set_opt (sbi->s_mount_opt, MINIX_DF);
841 			break;
842 		case Opt_grpid:
843 			set_opt (sbi->s_mount_opt, GRPID);
844 			break;
845 		case Opt_nogrpid:
846 			clear_opt (sbi->s_mount_opt, GRPID);
847 			break;
848 		case Opt_resuid:
849 			if (match_int(&args[0], &option))
850 				return 0;
851 			sbi->s_resuid = option;
852 			break;
853 		case Opt_resgid:
854 			if (match_int(&args[0], &option))
855 				return 0;
856 			sbi->s_resgid = option;
857 			break;
858 		case Opt_sb:
859 			/* handled by get_sb_block() instead of here */
860 			/* *sb_block = match_int(&args[0]); */
861 			break;
862 		case Opt_err_panic:
863 			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
864 			clear_opt (sbi->s_mount_opt, ERRORS_RO);
865 			set_opt (sbi->s_mount_opt, ERRORS_PANIC);
866 			break;
867 		case Opt_err_ro:
868 			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
869 			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
870 			set_opt (sbi->s_mount_opt, ERRORS_RO);
871 			break;
872 		case Opt_err_cont:
873 			clear_opt (sbi->s_mount_opt, ERRORS_RO);
874 			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
875 			set_opt (sbi->s_mount_opt, ERRORS_CONT);
876 			break;
877 		case Opt_nouid32:
878 			set_opt (sbi->s_mount_opt, NO_UID32);
879 			break;
880 		case Opt_nocheck:
881 			clear_opt (sbi->s_mount_opt, CHECK);
882 			break;
883 		case Opt_debug:
884 			set_opt (sbi->s_mount_opt, DEBUG);
885 			break;
886 		case Opt_oldalloc:
887 			set_opt (sbi->s_mount_opt, OLDALLOC);
888 			break;
889 		case Opt_orlov:
890 			clear_opt (sbi->s_mount_opt, OLDALLOC);
891 			break;
892 #ifdef CONFIG_EXT4DEV_FS_XATTR
893 		case Opt_user_xattr:
894 			set_opt (sbi->s_mount_opt, XATTR_USER);
895 			break;
896 		case Opt_nouser_xattr:
897 			clear_opt (sbi->s_mount_opt, XATTR_USER);
898 			break;
899 #else
900 		case Opt_user_xattr:
901 		case Opt_nouser_xattr:
902 			printk("EXT4 (no)user_xattr options not supported\n");
903 			break;
904 #endif
905 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
906 		case Opt_acl:
907 			set_opt(sbi->s_mount_opt, POSIX_ACL);
908 			break;
909 		case Opt_noacl:
910 			clear_opt(sbi->s_mount_opt, POSIX_ACL);
911 			break;
912 #else
913 		case Opt_acl:
914 		case Opt_noacl:
915 			printk("EXT4 (no)acl options not supported\n");
916 			break;
917 #endif
918 		case Opt_reservation:
919 			set_opt(sbi->s_mount_opt, RESERVATION);
920 			break;
921 		case Opt_noreservation:
922 			clear_opt(sbi->s_mount_opt, RESERVATION);
923 			break;
924 		case Opt_journal_update:
925 			/* @@@ FIXME */
926 			/* Eventually we will want to be able to create
927 			   a journal file here.  For now, only allow the
928 			   user to specify an existing inode to be the
929 			   journal file. */
930 			if (is_remount) {
931 				printk(KERN_ERR "EXT4-fs: cannot specify "
932 				       "journal on remount\n");
933 				return 0;
934 			}
935 			set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
936 			break;
937 		case Opt_journal_inum:
938 			if (is_remount) {
939 				printk(KERN_ERR "EXT4-fs: cannot specify "
940 				       "journal on remount\n");
941 				return 0;
942 			}
943 			if (match_int(&args[0], &option))
944 				return 0;
945 			*inum = option;
946 			break;
947 		case Opt_journal_dev:
948 			if (is_remount) {
949 				printk(KERN_ERR "EXT4-fs: cannot specify "
950 				       "journal on remount\n");
951 				return 0;
952 			}
953 			if (match_int(&args[0], &option))
954 				return 0;
955 			*journal_devnum = option;
956 			break;
957 		case Opt_noload:
958 			set_opt (sbi->s_mount_opt, NOLOAD);
959 			break;
960 		case Opt_commit:
961 			if (match_int(&args[0], &option))
962 				return 0;
963 			if (option < 0)
964 				return 0;
965 			if (option == 0)
966 				option = JBD_DEFAULT_MAX_COMMIT_AGE;
967 			sbi->s_commit_interval = HZ * option;
968 			break;
969 		case Opt_data_journal:
970 			data_opt = EXT4_MOUNT_JOURNAL_DATA;
971 			goto datacheck;
972 		case Opt_data_ordered:
973 			data_opt = EXT4_MOUNT_ORDERED_DATA;
974 			goto datacheck;
975 		case Opt_data_writeback:
976 			data_opt = EXT4_MOUNT_WRITEBACK_DATA;
977 		datacheck:
978 			if (is_remount) {
979 				if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
980 						!= data_opt) {
981 					printk(KERN_ERR
982 						"EXT4-fs: cannot change data "
983 						"mode on remount\n");
984 					return 0;
985 				}
986 			} else {
987 				sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
988 				sbi->s_mount_opt |= data_opt;
989 			}
990 			break;
991 #ifdef CONFIG_QUOTA
992 		case Opt_usrjquota:
993 			qtype = USRQUOTA;
994 			goto set_qf_name;
995 		case Opt_grpjquota:
996 			qtype = GRPQUOTA;
997 set_qf_name:
998 			if (sb_any_quota_enabled(sb)) {
999 				printk(KERN_ERR
1000 					"EXT4-fs: Cannot change journalled "
1001 					"quota options when quota turned on.\n");
1002 				return 0;
1003 			}
1004 			qname = match_strdup(&args[0]);
1005 			if (!qname) {
1006 				printk(KERN_ERR
1007 					"EXT4-fs: not enough memory for "
1008 					"storing quotafile name.\n");
1009 				return 0;
1010 			}
1011 			if (sbi->s_qf_names[qtype] &&
1012 			    strcmp(sbi->s_qf_names[qtype], qname)) {
1013 				printk(KERN_ERR
1014 					"EXT4-fs: %s quota file already "
1015 					"specified.\n", QTYPE2NAME(qtype));
1016 				kfree(qname);
1017 				return 0;
1018 			}
1019 			sbi->s_qf_names[qtype] = qname;
1020 			if (strchr(sbi->s_qf_names[qtype], '/')) {
1021 				printk(KERN_ERR
1022 					"EXT4-fs: quotafile must be on "
1023 					"filesystem root.\n");
1024 				kfree(sbi->s_qf_names[qtype]);
1025 				sbi->s_qf_names[qtype] = NULL;
1026 				return 0;
1027 			}
1028 			set_opt(sbi->s_mount_opt, QUOTA);
1029 			break;
1030 		case Opt_offusrjquota:
1031 			qtype = USRQUOTA;
1032 			goto clear_qf_name;
1033 		case Opt_offgrpjquota:
1034 			qtype = GRPQUOTA;
1035 clear_qf_name:
1036 			if (sb_any_quota_enabled(sb)) {
1037 				printk(KERN_ERR "EXT4-fs: Cannot change "
1038 					"journalled quota options when "
1039 					"quota turned on.\n");
1040 				return 0;
1041 			}
1042 			/*
1043 			 * The space will be released later when all options
1044 			 * are confirmed to be correct
1045 			 */
1046 			sbi->s_qf_names[qtype] = NULL;
1047 			break;
1048 		case Opt_jqfmt_vfsold:
1049 			sbi->s_jquota_fmt = QFMT_VFS_OLD;
1050 			break;
1051 		case Opt_jqfmt_vfsv0:
1052 			sbi->s_jquota_fmt = QFMT_VFS_V0;
1053 			break;
1054 		case Opt_quota:
1055 		case Opt_usrquota:
1056 			set_opt(sbi->s_mount_opt, QUOTA);
1057 			set_opt(sbi->s_mount_opt, USRQUOTA);
1058 			break;
1059 		case Opt_grpquota:
1060 			set_opt(sbi->s_mount_opt, QUOTA);
1061 			set_opt(sbi->s_mount_opt, GRPQUOTA);
1062 			break;
1063 		case Opt_noquota:
1064 			if (sb_any_quota_enabled(sb)) {
1065 				printk(KERN_ERR "EXT4-fs: Cannot change quota "
1066 					"options when quota turned on.\n");
1067 				return 0;
1068 			}
1069 			clear_opt(sbi->s_mount_opt, QUOTA);
1070 			clear_opt(sbi->s_mount_opt, USRQUOTA);
1071 			clear_opt(sbi->s_mount_opt, GRPQUOTA);
1072 			break;
1073 #else
1074 		case Opt_quota:
1075 		case Opt_usrquota:
1076 		case Opt_grpquota:
1077 		case Opt_usrjquota:
1078 		case Opt_grpjquota:
1079 		case Opt_offusrjquota:
1080 		case Opt_offgrpjquota:
1081 		case Opt_jqfmt_vfsold:
1082 		case Opt_jqfmt_vfsv0:
1083 			printk(KERN_ERR
1084 				"EXT4-fs: journalled quota options not "
1085 				"supported.\n");
1086 			break;
1087 		case Opt_noquota:
1088 			break;
1089 #endif
1090 		case Opt_abort:
1091 			set_opt(sbi->s_mount_opt, ABORT);
1092 			break;
1093 		case Opt_barrier:
1094 			if (match_int(&args[0], &option))
1095 				return 0;
1096 			if (option)
1097 				set_opt(sbi->s_mount_opt, BARRIER);
1098 			else
1099 				clear_opt(sbi->s_mount_opt, BARRIER);
1100 			break;
1101 		case Opt_ignore:
1102 			break;
1103 		case Opt_resize:
1104 			if (!is_remount) {
1105 				printk("EXT4-fs: resize option only available "
1106 					"for remount\n");
1107 				return 0;
1108 			}
1109 			if (match_int(&args[0], &option) != 0)
1110 				return 0;
1111 			*n_blocks_count = option;
1112 			break;
1113 		case Opt_nobh:
1114 			set_opt(sbi->s_mount_opt, NOBH);
1115 			break;
1116 		case Opt_bh:
1117 			clear_opt(sbi->s_mount_opt, NOBH);
1118 			break;
1119 		case Opt_extents:
1120 			set_opt (sbi->s_mount_opt, EXTENTS);
1121 			break;
1122 		default:
1123 			printk (KERN_ERR
1124 				"EXT4-fs: Unrecognized mount option \"%s\" "
1125 				"or missing value\n", p);
1126 			return 0;
1127 		}
1128 	}
1129 #ifdef CONFIG_QUOTA
1130 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1131 		if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1132 		     sbi->s_qf_names[USRQUOTA])
1133 			clear_opt(sbi->s_mount_opt, USRQUOTA);
1134 
1135 		if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1136 		     sbi->s_qf_names[GRPQUOTA])
1137 			clear_opt(sbi->s_mount_opt, GRPQUOTA);
1138 
1139 		if ((sbi->s_qf_names[USRQUOTA] &&
1140 				(sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1141 		    (sbi->s_qf_names[GRPQUOTA] &&
1142 				(sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1143 			printk(KERN_ERR "EXT4-fs: old and new quota "
1144 					"format mixing.\n");
1145 			return 0;
1146 		}
1147 
1148 		if (!sbi->s_jquota_fmt) {
1149 			printk(KERN_ERR "EXT4-fs: journalled quota format "
1150 					"not specified.\n");
1151 			return 0;
1152 		}
1153 	} else {
1154 		if (sbi->s_jquota_fmt) {
1155 			printk(KERN_ERR "EXT4-fs: journalled quota format "
1156 					"specified with no journalling "
1157 					"enabled.\n");
1158 			return 0;
1159 		}
1160 	}
1161 #endif
1162 	return 1;
1163 }
1164 
1165 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1166 			    int read_only)
1167 {
1168 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1169 	int res = 0;
1170 
1171 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1172 		printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1173 			"forcing read-only mode\n");
1174 		res = MS_RDONLY;
1175 	}
1176 	if (read_only)
1177 		return res;
1178 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1179 		printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1180 			"running e2fsck is recommended\n");
1181 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1182 		printk (KERN_WARNING
1183 			"EXT4-fs warning: mounting fs with errors, "
1184 			"running e2fsck is recommended\n");
1185 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1186 		 le16_to_cpu(es->s_mnt_count) >=
1187 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1188 		printk (KERN_WARNING
1189 			"EXT4-fs warning: maximal mount count reached, "
1190 			"running e2fsck is recommended\n");
1191 	else if (le32_to_cpu(es->s_checkinterval) &&
1192 		(le32_to_cpu(es->s_lastcheck) +
1193 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1194 		printk (KERN_WARNING
1195 			"EXT4-fs warning: checktime reached, "
1196 			"running e2fsck is recommended\n");
1197 #if 0
1198 		/* @@@ We _will_ want to clear the valid bit if we find
1199 		 * inconsistencies, to force a fsck at reboot.  But for
1200 		 * a plain journaled filesystem we can keep it set as
1201 		 * valid forever! :)
1202 		 */
1203 	es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT4_VALID_FS);
1204 #endif
1205 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1206 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1207 	es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
1208 	es->s_mtime = cpu_to_le32(get_seconds());
1209 	ext4_update_dynamic_rev(sb);
1210 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1211 
1212 	ext4_commit_super(sb, es, 1);
1213 	if (test_opt(sb, DEBUG))
1214 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1215 				"bpg=%lu, ipg=%lu, mo=%04lx]\n",
1216 			sb->s_blocksize,
1217 			sbi->s_groups_count,
1218 			EXT4_BLOCKS_PER_GROUP(sb),
1219 			EXT4_INODES_PER_GROUP(sb),
1220 			sbi->s_mount_opt);
1221 
1222 	printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1223 	if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1224 		char b[BDEVNAME_SIZE];
1225 
1226 		printk("external journal on %s\n",
1227 			bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1228 	} else {
1229 		printk("internal journal\n");
1230 	}
1231 	return res;
1232 }
1233 
1234 /* Called at mount-time, super-block is locked */
1235 static int ext4_check_descriptors (struct super_block * sb)
1236 {
1237 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1238 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1239 	ext4_fsblk_t last_block;
1240 	ext4_fsblk_t block_bitmap;
1241 	ext4_fsblk_t inode_bitmap;
1242 	ext4_fsblk_t inode_table;
1243 	struct ext4_group_desc * gdp = NULL;
1244 	int desc_block = 0;
1245 	int i;
1246 
1247 	ext4_debug ("Checking group descriptors");
1248 
1249 	for (i = 0; i < sbi->s_groups_count; i++)
1250 	{
1251 		if (i == sbi->s_groups_count - 1)
1252 			last_block = ext4_blocks_count(sbi->s_es) - 1;
1253 		else
1254 			last_block = first_block +
1255 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
1256 
1257 		if ((i % EXT4_DESC_PER_BLOCK(sb)) == 0)
1258 			gdp = (struct ext4_group_desc *)
1259 					sbi->s_group_desc[desc_block++]->b_data;
1260 		block_bitmap = ext4_block_bitmap(sb, gdp);
1261 		if (block_bitmap < first_block || block_bitmap > last_block)
1262 		{
1263 			ext4_error (sb, "ext4_check_descriptors",
1264 				    "Block bitmap for group %d"
1265 				    " not in group (block %llu)!",
1266 				    i, block_bitmap);
1267 			return 0;
1268 		}
1269 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
1270 		if (inode_bitmap < first_block || inode_bitmap > last_block)
1271 		{
1272 			ext4_error (sb, "ext4_check_descriptors",
1273 				    "Inode bitmap for group %d"
1274 				    " not in group (block %llu)!",
1275 				    i, inode_bitmap);
1276 			return 0;
1277 		}
1278 		inode_table = ext4_inode_table(sb, gdp);
1279 		if (inode_table < first_block ||
1280 		    inode_table + sbi->s_itb_per_group > last_block)
1281 		{
1282 			ext4_error (sb, "ext4_check_descriptors",
1283 				    "Inode table for group %d"
1284 				    " not in group (block %llu)!",
1285 				    i, inode_table);
1286 			return 0;
1287 		}
1288 		first_block += EXT4_BLOCKS_PER_GROUP(sb);
1289 		gdp = (struct ext4_group_desc *)
1290 			((__u8 *)gdp + EXT4_DESC_SIZE(sb));
1291 	}
1292 
1293 	ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1294 	sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1295 	return 1;
1296 }
1297 
1298 
1299 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1300  * the superblock) which were deleted from all directories, but held open by
1301  * a process at the time of a crash.  We walk the list and try to delete these
1302  * inodes at recovery time (only with a read-write filesystem).
1303  *
1304  * In order to keep the orphan inode chain consistent during traversal (in
1305  * case of crash during recovery), we link each inode into the superblock
1306  * orphan list_head and handle it the same way as an inode deletion during
1307  * normal operation (which journals the operations for us).
1308  *
1309  * We only do an iget() and an iput() on each inode, which is very safe if we
1310  * accidentally point at an in-use or already deleted inode.  The worst that
1311  * can happen in this case is that we get a "bit already cleared" message from
1312  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1313  * e2fsck was run on this filesystem, and it must have already done the orphan
1314  * inode cleanup for us, so we can safely abort without any further action.
1315  */
1316 static void ext4_orphan_cleanup (struct super_block * sb,
1317 				 struct ext4_super_block * es)
1318 {
1319 	unsigned int s_flags = sb->s_flags;
1320 	int nr_orphans = 0, nr_truncates = 0;
1321 #ifdef CONFIG_QUOTA
1322 	int i;
1323 #endif
1324 	if (!es->s_last_orphan) {
1325 		jbd_debug(4, "no orphan inodes to clean up\n");
1326 		return;
1327 	}
1328 
1329 	if (bdev_read_only(sb->s_bdev)) {
1330 		printk(KERN_ERR "EXT4-fs: write access "
1331 			"unavailable, skipping orphan cleanup.\n");
1332 		return;
1333 	}
1334 
1335 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1336 		if (es->s_last_orphan)
1337 			jbd_debug(1, "Errors on filesystem, "
1338 				  "clearing orphan list.\n");
1339 		es->s_last_orphan = 0;
1340 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1341 		return;
1342 	}
1343 
1344 	if (s_flags & MS_RDONLY) {
1345 		printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1346 		       sb->s_id);
1347 		sb->s_flags &= ~MS_RDONLY;
1348 	}
1349 #ifdef CONFIG_QUOTA
1350 	/* Needed for iput() to work correctly and not trash data */
1351 	sb->s_flags |= MS_ACTIVE;
1352 	/* Turn on quotas so that they are updated correctly */
1353 	for (i = 0; i < MAXQUOTAS; i++) {
1354 		if (EXT4_SB(sb)->s_qf_names[i]) {
1355 			int ret = ext4_quota_on_mount(sb, i);
1356 			if (ret < 0)
1357 				printk(KERN_ERR
1358 					"EXT4-fs: Cannot turn on journalled "
1359 					"quota: error %d\n", ret);
1360 		}
1361 	}
1362 #endif
1363 
1364 	while (es->s_last_orphan) {
1365 		struct inode *inode;
1366 
1367 		if (!(inode =
1368 		      ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
1369 			es->s_last_orphan = 0;
1370 			break;
1371 		}
1372 
1373 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1374 		DQUOT_INIT(inode);
1375 		if (inode->i_nlink) {
1376 			printk(KERN_DEBUG
1377 				"%s: truncating inode %lu to %Ld bytes\n",
1378 				__FUNCTION__, inode->i_ino, inode->i_size);
1379 			jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1380 				  inode->i_ino, inode->i_size);
1381 			ext4_truncate(inode);
1382 			nr_truncates++;
1383 		} else {
1384 			printk(KERN_DEBUG
1385 				"%s: deleting unreferenced inode %lu\n",
1386 				__FUNCTION__, inode->i_ino);
1387 			jbd_debug(2, "deleting unreferenced inode %lu\n",
1388 				  inode->i_ino);
1389 			nr_orphans++;
1390 		}
1391 		iput(inode);  /* The delete magic happens here! */
1392 	}
1393 
1394 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1395 
1396 	if (nr_orphans)
1397 		printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1398 		       sb->s_id, PLURAL(nr_orphans));
1399 	if (nr_truncates)
1400 		printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1401 		       sb->s_id, PLURAL(nr_truncates));
1402 #ifdef CONFIG_QUOTA
1403 	/* Turn quotas off */
1404 	for (i = 0; i < MAXQUOTAS; i++) {
1405 		if (sb_dqopt(sb)->files[i])
1406 			vfs_quota_off(sb, i);
1407 	}
1408 #endif
1409 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1410 }
1411 
1412 #define log2(n) ffz(~(n))
1413 
1414 /*
1415  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
1416  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
1417  * We need to be 1 filesystem block less than the 2^32 sector limit.
1418  */
1419 static loff_t ext4_max_size(int bits)
1420 {
1421 	loff_t res = EXT4_NDIR_BLOCKS;
1422 	/* This constant is calculated to be the largest file size for a
1423 	 * dense, 4k-blocksize file such that the total number of
1424 	 * sectors in the file, including data and all indirect blocks,
1425 	 * does not exceed 2^32. */
1426 	const loff_t upper_limit = 0x1ff7fffd000LL;
1427 
1428 	res += 1LL << (bits-2);
1429 	res += 1LL << (2*(bits-2));
1430 	res += 1LL << (3*(bits-2));
1431 	res <<= bits;
1432 	if (res > upper_limit)
1433 		res = upper_limit;
1434 	return res;
1435 }
1436 
1437 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1438 				ext4_fsblk_t logical_sb_block, int nr)
1439 {
1440 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1441 	unsigned long bg, first_meta_bg;
1442 	int has_super = 0;
1443 
1444 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1445 
1446 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1447 	    nr < first_meta_bg)
1448 		return logical_sb_block + nr + 1;
1449 	bg = sbi->s_desc_per_block * nr;
1450 	if (ext4_bg_has_super(sb, bg))
1451 		has_super = 1;
1452 	return (has_super + ext4_group_first_block_no(sb, bg));
1453 }
1454 
1455 
1456 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1457 {
1458 	struct buffer_head * bh;
1459 	struct ext4_super_block *es = NULL;
1460 	struct ext4_sb_info *sbi;
1461 	ext4_fsblk_t block;
1462 	ext4_fsblk_t sb_block = get_sb_block(&data);
1463 	ext4_fsblk_t logical_sb_block;
1464 	unsigned long offset = 0;
1465 	unsigned int journal_inum = 0;
1466 	unsigned long journal_devnum = 0;
1467 	unsigned long def_mount_opts;
1468 	struct inode *root;
1469 	int blocksize;
1470 	int hblock;
1471 	int db_count;
1472 	int i;
1473 	int needs_recovery;
1474 	__le32 features;
1475 	__u64 blocks_count;
1476 
1477 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1478 	if (!sbi)
1479 		return -ENOMEM;
1480 	sb->s_fs_info = sbi;
1481 	sbi->s_mount_opt = 0;
1482 	sbi->s_resuid = EXT4_DEF_RESUID;
1483 	sbi->s_resgid = EXT4_DEF_RESGID;
1484 
1485 	unlock_kernel();
1486 
1487 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1488 	if (!blocksize) {
1489 		printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1490 		goto out_fail;
1491 	}
1492 
1493 	/*
1494 	 * The ext4 superblock will not be buffer aligned for other than 1kB
1495 	 * block sizes.  We need to calculate the offset from buffer start.
1496 	 */
1497 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1498 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1499 		offset = do_div(logical_sb_block, blocksize);
1500 	} else {
1501 		logical_sb_block = sb_block;
1502 	}
1503 
1504 	if (!(bh = sb_bread(sb, logical_sb_block))) {
1505 		printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1506 		goto out_fail;
1507 	}
1508 	/*
1509 	 * Note: s_es must be initialized as soon as possible because
1510 	 *       some ext4 macro-instructions depend on its value
1511 	 */
1512 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1513 	sbi->s_es = es;
1514 	sb->s_magic = le16_to_cpu(es->s_magic);
1515 	if (sb->s_magic != EXT4_SUPER_MAGIC)
1516 		goto cantfind_ext4;
1517 
1518 	/* Set defaults before we parse the mount options */
1519 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1520 	if (def_mount_opts & EXT4_DEFM_DEBUG)
1521 		set_opt(sbi->s_mount_opt, DEBUG);
1522 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1523 		set_opt(sbi->s_mount_opt, GRPID);
1524 	if (def_mount_opts & EXT4_DEFM_UID16)
1525 		set_opt(sbi->s_mount_opt, NO_UID32);
1526 #ifdef CONFIG_EXT4DEV_FS_XATTR
1527 	if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1528 		set_opt(sbi->s_mount_opt, XATTR_USER);
1529 #endif
1530 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1531 	if (def_mount_opts & EXT4_DEFM_ACL)
1532 		set_opt(sbi->s_mount_opt, POSIX_ACL);
1533 #endif
1534 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1535 		sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1536 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1537 		sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1538 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1539 		sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1540 
1541 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1542 		set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1543 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_RO)
1544 		set_opt(sbi->s_mount_opt, ERRORS_RO);
1545 	else
1546 		set_opt(sbi->s_mount_opt, ERRORS_CONT);
1547 
1548 	sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1549 	sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1550 
1551 	set_opt(sbi->s_mount_opt, RESERVATION);
1552 
1553 	if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1554 			    NULL, 0))
1555 		goto failed_mount;
1556 
1557 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1558 		((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1559 
1560 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1561 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1562 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1563 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1564 		printk(KERN_WARNING
1565 		       "EXT4-fs warning: feature flags set on rev 0 fs, "
1566 		       "running e2fsck is recommended\n");
1567 	/*
1568 	 * Check feature flags regardless of the revision level, since we
1569 	 * previously didn't change the revision level when setting the flags,
1570 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
1571 	 */
1572 	features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1573 	if (features) {
1574 		printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1575 		       "unsupported optional features (%x).\n",
1576 		       sb->s_id, le32_to_cpu(features));
1577 		goto failed_mount;
1578 	}
1579 	features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1580 	if (!(sb->s_flags & MS_RDONLY) && features) {
1581 		printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1582 		       "unsupported optional features (%x).\n",
1583 		       sb->s_id, le32_to_cpu(features));
1584 		goto failed_mount;
1585 	}
1586 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1587 
1588 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1589 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
1590 		printk(KERN_ERR
1591 		       "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1592 		       blocksize, sb->s_id);
1593 		goto failed_mount;
1594 	}
1595 
1596 	hblock = bdev_hardsect_size(sb->s_bdev);
1597 	if (sb->s_blocksize != blocksize) {
1598 		/*
1599 		 * Make sure the blocksize for the filesystem is larger
1600 		 * than the hardware sectorsize for the machine.
1601 		 */
1602 		if (blocksize < hblock) {
1603 			printk(KERN_ERR "EXT4-fs: blocksize %d too small for "
1604 			       "device blocksize %d.\n", blocksize, hblock);
1605 			goto failed_mount;
1606 		}
1607 
1608 		brelse (bh);
1609 		sb_set_blocksize(sb, blocksize);
1610 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1611 		offset = do_div(logical_sb_block, blocksize);
1612 		bh = sb_bread(sb, logical_sb_block);
1613 		if (!bh) {
1614 			printk(KERN_ERR
1615 			       "EXT4-fs: Can't read superblock on 2nd try.\n");
1616 			goto failed_mount;
1617 		}
1618 		es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1619 		sbi->s_es = es;
1620 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1621 			printk (KERN_ERR
1622 				"EXT4-fs: Magic mismatch, very weird !\n");
1623 			goto failed_mount;
1624 		}
1625 	}
1626 
1627 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
1628 
1629 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
1630 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
1631 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
1632 	} else {
1633 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1634 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1635 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
1636 		    (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
1637 		    (sbi->s_inode_size > blocksize)) {
1638 			printk (KERN_ERR
1639 				"EXT4-fs: unsupported inode size: %d\n",
1640 				sbi->s_inode_size);
1641 			goto failed_mount;
1642 		}
1643 	}
1644 	sbi->s_frag_size = EXT4_MIN_FRAG_SIZE <<
1645 				   le32_to_cpu(es->s_log_frag_size);
1646 	if (blocksize != sbi->s_frag_size) {
1647 		printk(KERN_ERR
1648 		       "EXT4-fs: fragsize %lu != blocksize %u (unsupported)\n",
1649 		       sbi->s_frag_size, blocksize);
1650 		goto failed_mount;
1651 	}
1652 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
1653 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
1654 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
1655 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
1656 		    sbi->s_desc_size & (sbi->s_desc_size - 1)) {
1657 			printk(KERN_ERR
1658 			       "EXT4-fs: unsupported descriptor size %lu\n",
1659 			       sbi->s_desc_size);
1660 			goto failed_mount;
1661 		}
1662 	} else
1663 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
1664 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1665 	sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1666 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1667 	if (EXT4_INODE_SIZE(sb) == 0)
1668 		goto cantfind_ext4;
1669 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
1670 	if (sbi->s_inodes_per_block == 0)
1671 		goto cantfind_ext4;
1672 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
1673 					sbi->s_inodes_per_block;
1674 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
1675 	sbi->s_sbh = bh;
1676 	sbi->s_mount_state = le16_to_cpu(es->s_state);
1677 	sbi->s_addr_per_block_bits = log2(EXT4_ADDR_PER_BLOCK(sb));
1678 	sbi->s_desc_per_block_bits = log2(EXT4_DESC_PER_BLOCK(sb));
1679 	for (i=0; i < 4; i++)
1680 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
1681 	sbi->s_def_hash_version = es->s_def_hash_version;
1682 
1683 	if (sbi->s_blocks_per_group > blocksize * 8) {
1684 		printk (KERN_ERR
1685 			"EXT4-fs: #blocks per group too big: %lu\n",
1686 			sbi->s_blocks_per_group);
1687 		goto failed_mount;
1688 	}
1689 	if (sbi->s_frags_per_group > blocksize * 8) {
1690 		printk (KERN_ERR
1691 			"EXT4-fs: #fragments per group too big: %lu\n",
1692 			sbi->s_frags_per_group);
1693 		goto failed_mount;
1694 	}
1695 	if (sbi->s_inodes_per_group > blocksize * 8) {
1696 		printk (KERN_ERR
1697 			"EXT4-fs: #inodes per group too big: %lu\n",
1698 			sbi->s_inodes_per_group);
1699 		goto failed_mount;
1700 	}
1701 
1702 	if (ext4_blocks_count(es) >
1703 		    (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1704 		printk(KERN_ERR "EXT4-fs: filesystem on %s:"
1705 			" too large to mount safely\n", sb->s_id);
1706 		if (sizeof(sector_t) < 8)
1707 			printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
1708 					"enabled\n");
1709 		goto failed_mount;
1710 	}
1711 
1712 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
1713 		goto cantfind_ext4;
1714 	blocks_count = (ext4_blocks_count(es) -
1715 			le32_to_cpu(es->s_first_data_block) +
1716 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
1717 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
1718 	sbi->s_groups_count = blocks_count;
1719 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
1720 		   EXT4_DESC_PER_BLOCK(sb);
1721 	sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
1722 				    GFP_KERNEL);
1723 	if (sbi->s_group_desc == NULL) {
1724 		printk (KERN_ERR "EXT4-fs: not enough memory\n");
1725 		goto failed_mount;
1726 	}
1727 
1728 	bgl_lock_init(&sbi->s_blockgroup_lock);
1729 
1730 	for (i = 0; i < db_count; i++) {
1731 		block = descriptor_loc(sb, logical_sb_block, i);
1732 		sbi->s_group_desc[i] = sb_bread(sb, block);
1733 		if (!sbi->s_group_desc[i]) {
1734 			printk (KERN_ERR "EXT4-fs: "
1735 				"can't read group descriptor %d\n", i);
1736 			db_count = i;
1737 			goto failed_mount2;
1738 		}
1739 	}
1740 	if (!ext4_check_descriptors (sb)) {
1741 		printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
1742 		goto failed_mount2;
1743 	}
1744 	sbi->s_gdb_count = db_count;
1745 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1746 	spin_lock_init(&sbi->s_next_gen_lock);
1747 
1748 	percpu_counter_init(&sbi->s_freeblocks_counter,
1749 		ext4_count_free_blocks(sb));
1750 	percpu_counter_init(&sbi->s_freeinodes_counter,
1751 		ext4_count_free_inodes(sb));
1752 	percpu_counter_init(&sbi->s_dirs_counter,
1753 		ext4_count_dirs(sb));
1754 
1755 	/* per fileystem reservation list head & lock */
1756 	spin_lock_init(&sbi->s_rsv_window_lock);
1757 	sbi->s_rsv_window_root = RB_ROOT;
1758 	/* Add a single, static dummy reservation to the start of the
1759 	 * reservation window list --- it gives us a placeholder for
1760 	 * append-at-start-of-list which makes the allocation logic
1761 	 * _much_ simpler. */
1762 	sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1763 	sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1764 	sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1765 	sbi->s_rsv_window_head.rsv_goal_size = 0;
1766 	ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
1767 
1768 	/*
1769 	 * set up enough so that it can read an inode
1770 	 */
1771 	sb->s_op = &ext4_sops;
1772 	sb->s_export_op = &ext4_export_ops;
1773 	sb->s_xattr = ext4_xattr_handlers;
1774 #ifdef CONFIG_QUOTA
1775 	sb->s_qcop = &ext4_qctl_operations;
1776 	sb->dq_op = &ext4_quota_operations;
1777 #endif
1778 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
1779 
1780 	sb->s_root = NULL;
1781 
1782 	needs_recovery = (es->s_last_orphan != 0 ||
1783 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
1784 				    EXT4_FEATURE_INCOMPAT_RECOVER));
1785 
1786 	/*
1787 	 * The first inode we look at is the journal inode.  Don't try
1788 	 * root first: it may be modified in the journal!
1789 	 */
1790 	if (!test_opt(sb, NOLOAD) &&
1791 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
1792 		if (ext4_load_journal(sb, es, journal_devnum))
1793 			goto failed_mount3;
1794 	} else if (journal_inum) {
1795 		if (ext4_create_journal(sb, es, journal_inum))
1796 			goto failed_mount3;
1797 	} else {
1798 		if (!silent)
1799 			printk (KERN_ERR
1800 				"ext4: No journal on filesystem on %s\n",
1801 				sb->s_id);
1802 		goto failed_mount3;
1803 	}
1804 
1805 	/* We have now updated the journal if required, so we can
1806 	 * validate the data journaling mode. */
1807 	switch (test_opt(sb, DATA_FLAGS)) {
1808 	case 0:
1809 		/* No mode set, assume a default based on the journal
1810 		 * capabilities: ORDERED_DATA if the journal can
1811 		 * cope, else JOURNAL_DATA
1812 		 */
1813 		if (jbd2_journal_check_available_features
1814 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
1815 			set_opt(sbi->s_mount_opt, ORDERED_DATA);
1816 		else
1817 			set_opt(sbi->s_mount_opt, JOURNAL_DATA);
1818 		break;
1819 
1820 	case EXT4_MOUNT_ORDERED_DATA:
1821 	case EXT4_MOUNT_WRITEBACK_DATA:
1822 		if (!jbd2_journal_check_available_features
1823 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
1824 			printk(KERN_ERR "EXT4-fs: Journal does not support "
1825 			       "requested data journaling mode\n");
1826 			goto failed_mount4;
1827 		}
1828 	default:
1829 		break;
1830 	}
1831 
1832 	if (test_opt(sb, NOBH)) {
1833 		if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
1834 			printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
1835 				"its supported only with writeback mode\n");
1836 			clear_opt(sbi->s_mount_opt, NOBH);
1837 		}
1838 	}
1839 	/*
1840 	 * The jbd2_journal_load will have done any necessary log recovery,
1841 	 * so we can safely mount the rest of the filesystem now.
1842 	 */
1843 
1844 	root = iget(sb, EXT4_ROOT_INO);
1845 	sb->s_root = d_alloc_root(root);
1846 	if (!sb->s_root) {
1847 		printk(KERN_ERR "EXT4-fs: get root inode failed\n");
1848 		iput(root);
1849 		goto failed_mount4;
1850 	}
1851 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1852 		dput(sb->s_root);
1853 		sb->s_root = NULL;
1854 		printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
1855 		goto failed_mount4;
1856 	}
1857 
1858 	ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1859 	/*
1860 	 * akpm: core read_super() calls in here with the superblock locked.
1861 	 * That deadlocks, because orphan cleanup needs to lock the superblock
1862 	 * in numerous places.  Here we just pop the lock - it's relatively
1863 	 * harmless, because we are now ready to accept write_super() requests,
1864 	 * and aviro says that's the only reason for hanging onto the
1865 	 * superblock lock.
1866 	 */
1867 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
1868 	ext4_orphan_cleanup(sb, es);
1869 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
1870 	if (needs_recovery)
1871 		printk (KERN_INFO "EXT4-fs: recovery complete.\n");
1872 	ext4_mark_recovery_complete(sb, es);
1873 	printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
1874 		test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
1875 		test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
1876 		"writeback");
1877 
1878 	ext4_ext_init(sb);
1879 
1880 	lock_kernel();
1881 	return 0;
1882 
1883 cantfind_ext4:
1884 	if (!silent)
1885 		printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
1886 		       sb->s_id);
1887 	goto failed_mount;
1888 
1889 failed_mount4:
1890 	jbd2_journal_destroy(sbi->s_journal);
1891 failed_mount3:
1892 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
1893 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1894 	percpu_counter_destroy(&sbi->s_dirs_counter);
1895 failed_mount2:
1896 	for (i = 0; i < db_count; i++)
1897 		brelse(sbi->s_group_desc[i]);
1898 	kfree(sbi->s_group_desc);
1899 failed_mount:
1900 #ifdef CONFIG_QUOTA
1901 	for (i = 0; i < MAXQUOTAS; i++)
1902 		kfree(sbi->s_qf_names[i]);
1903 #endif
1904 	ext4_blkdev_remove(sbi);
1905 	brelse(bh);
1906 out_fail:
1907 	sb->s_fs_info = NULL;
1908 	kfree(sbi);
1909 	lock_kernel();
1910 	return -EINVAL;
1911 }
1912 
1913 /*
1914  * Setup any per-fs journal parameters now.  We'll do this both on
1915  * initial mount, once the journal has been initialised but before we've
1916  * done any recovery; and again on any subsequent remount.
1917  */
1918 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
1919 {
1920 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1921 
1922 	if (sbi->s_commit_interval)
1923 		journal->j_commit_interval = sbi->s_commit_interval;
1924 	/* We could also set up an ext4-specific default for the commit
1925 	 * interval here, but for now we'll just fall back to the jbd
1926 	 * default. */
1927 
1928 	spin_lock(&journal->j_state_lock);
1929 	if (test_opt(sb, BARRIER))
1930 		journal->j_flags |= JBD2_BARRIER;
1931 	else
1932 		journal->j_flags &= ~JBD2_BARRIER;
1933 	spin_unlock(&journal->j_state_lock);
1934 }
1935 
1936 static journal_t *ext4_get_journal(struct super_block *sb,
1937 				   unsigned int journal_inum)
1938 {
1939 	struct inode *journal_inode;
1940 	journal_t *journal;
1941 
1942 	/* First, test for the existence of a valid inode on disk.  Bad
1943 	 * things happen if we iget() an unused inode, as the subsequent
1944 	 * iput() will try to delete it. */
1945 
1946 	journal_inode = iget(sb, journal_inum);
1947 	if (!journal_inode) {
1948 		printk(KERN_ERR "EXT4-fs: no journal found.\n");
1949 		return NULL;
1950 	}
1951 	if (!journal_inode->i_nlink) {
1952 		make_bad_inode(journal_inode);
1953 		iput(journal_inode);
1954 		printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
1955 		return NULL;
1956 	}
1957 
1958 	jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
1959 		  journal_inode, journal_inode->i_size);
1960 	if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
1961 		printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
1962 		iput(journal_inode);
1963 		return NULL;
1964 	}
1965 
1966 	journal = jbd2_journal_init_inode(journal_inode);
1967 	if (!journal) {
1968 		printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
1969 		iput(journal_inode);
1970 		return NULL;
1971 	}
1972 	journal->j_private = sb;
1973 	ext4_init_journal_params(sb, journal);
1974 	return journal;
1975 }
1976 
1977 static journal_t *ext4_get_dev_journal(struct super_block *sb,
1978 				       dev_t j_dev)
1979 {
1980 	struct buffer_head * bh;
1981 	journal_t *journal;
1982 	ext4_fsblk_t start;
1983 	ext4_fsblk_t len;
1984 	int hblock, blocksize;
1985 	ext4_fsblk_t sb_block;
1986 	unsigned long offset;
1987 	struct ext4_super_block * es;
1988 	struct block_device *bdev;
1989 
1990 	bdev = ext4_blkdev_get(j_dev);
1991 	if (bdev == NULL)
1992 		return NULL;
1993 
1994 	if (bd_claim(bdev, sb)) {
1995 		printk(KERN_ERR
1996 			"EXT4: failed to claim external journal device.\n");
1997 		blkdev_put(bdev);
1998 		return NULL;
1999 	}
2000 
2001 	blocksize = sb->s_blocksize;
2002 	hblock = bdev_hardsect_size(bdev);
2003 	if (blocksize < hblock) {
2004 		printk(KERN_ERR
2005 			"EXT4-fs: blocksize too small for journal device.\n");
2006 		goto out_bdev;
2007 	}
2008 
2009 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2010 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2011 	set_blocksize(bdev, blocksize);
2012 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
2013 		printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2014 		       "external journal\n");
2015 		goto out_bdev;
2016 	}
2017 
2018 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2019 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2020 	    !(le32_to_cpu(es->s_feature_incompat) &
2021 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2022 		printk(KERN_ERR "EXT4-fs: external journal has "
2023 					"bad superblock\n");
2024 		brelse(bh);
2025 		goto out_bdev;
2026 	}
2027 
2028 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2029 		printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2030 		brelse(bh);
2031 		goto out_bdev;
2032 	}
2033 
2034 	len = ext4_blocks_count(es);
2035 	start = sb_block + 1;
2036 	brelse(bh);	/* we're done with the superblock */
2037 
2038 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2039 					start, len, blocksize);
2040 	if (!journal) {
2041 		printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2042 		goto out_bdev;
2043 	}
2044 	journal->j_private = sb;
2045 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
2046 	wait_on_buffer(journal->j_sb_buffer);
2047 	if (!buffer_uptodate(journal->j_sb_buffer)) {
2048 		printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2049 		goto out_journal;
2050 	}
2051 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2052 		printk(KERN_ERR "EXT4-fs: External journal has more than one "
2053 					"user (unsupported) - %d\n",
2054 			be32_to_cpu(journal->j_superblock->s_nr_users));
2055 		goto out_journal;
2056 	}
2057 	EXT4_SB(sb)->journal_bdev = bdev;
2058 	ext4_init_journal_params(sb, journal);
2059 	return journal;
2060 out_journal:
2061 	jbd2_journal_destroy(journal);
2062 out_bdev:
2063 	ext4_blkdev_put(bdev);
2064 	return NULL;
2065 }
2066 
2067 static int ext4_load_journal(struct super_block *sb,
2068 			     struct ext4_super_block *es,
2069 			     unsigned long journal_devnum)
2070 {
2071 	journal_t *journal;
2072 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2073 	dev_t journal_dev;
2074 	int err = 0;
2075 	int really_read_only;
2076 
2077 	if (journal_devnum &&
2078 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2079 		printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2080 			"numbers have changed\n");
2081 		journal_dev = new_decode_dev(journal_devnum);
2082 	} else
2083 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2084 
2085 	really_read_only = bdev_read_only(sb->s_bdev);
2086 
2087 	/*
2088 	 * Are we loading a blank journal or performing recovery after a
2089 	 * crash?  For recovery, we need to check in advance whether we
2090 	 * can get read-write access to the device.
2091 	 */
2092 
2093 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2094 		if (sb->s_flags & MS_RDONLY) {
2095 			printk(KERN_INFO "EXT4-fs: INFO: recovery "
2096 					"required on readonly filesystem.\n");
2097 			if (really_read_only) {
2098 				printk(KERN_ERR "EXT4-fs: write access "
2099 					"unavailable, cannot proceed.\n");
2100 				return -EROFS;
2101 			}
2102 			printk (KERN_INFO "EXT4-fs: write access will "
2103 					"be enabled during recovery.\n");
2104 		}
2105 	}
2106 
2107 	if (journal_inum && journal_dev) {
2108 		printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2109 		       "and inode journals!\n");
2110 		return -EINVAL;
2111 	}
2112 
2113 	if (journal_inum) {
2114 		if (!(journal = ext4_get_journal(sb, journal_inum)))
2115 			return -EINVAL;
2116 	} else {
2117 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2118 			return -EINVAL;
2119 	}
2120 
2121 	if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2122 		err = jbd2_journal_update_format(journal);
2123 		if (err)  {
2124 			printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2125 			jbd2_journal_destroy(journal);
2126 			return err;
2127 		}
2128 	}
2129 
2130 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2131 		err = jbd2_journal_wipe(journal, !really_read_only);
2132 	if (!err)
2133 		err = jbd2_journal_load(journal);
2134 
2135 	if (err) {
2136 		printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2137 		jbd2_journal_destroy(journal);
2138 		return err;
2139 	}
2140 
2141 	EXT4_SB(sb)->s_journal = journal;
2142 	ext4_clear_journal_err(sb, es);
2143 
2144 	if (journal_devnum &&
2145 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2146 		es->s_journal_dev = cpu_to_le32(journal_devnum);
2147 		sb->s_dirt = 1;
2148 
2149 		/* Make sure we flush the recovery flag to disk. */
2150 		ext4_commit_super(sb, es, 1);
2151 	}
2152 
2153 	return 0;
2154 }
2155 
2156 static int ext4_create_journal(struct super_block * sb,
2157 			       struct ext4_super_block * es,
2158 			       unsigned int journal_inum)
2159 {
2160 	journal_t *journal;
2161 	int err;
2162 
2163 	if (sb->s_flags & MS_RDONLY) {
2164 		printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2165 				"create journal.\n");
2166 		return -EROFS;
2167 	}
2168 
2169 	journal = ext4_get_journal(sb, journal_inum);
2170 	if (!journal)
2171 		return -EINVAL;
2172 
2173 	printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2174 	       journal_inum);
2175 
2176 	err = jbd2_journal_create(journal);
2177 	if (err) {
2178 		printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2179 		jbd2_journal_destroy(journal);
2180 		return -EIO;
2181 	}
2182 
2183 	EXT4_SB(sb)->s_journal = journal;
2184 
2185 	ext4_update_dynamic_rev(sb);
2186 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2187 	EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2188 
2189 	es->s_journal_inum = cpu_to_le32(journal_inum);
2190 	sb->s_dirt = 1;
2191 
2192 	/* Make sure we flush the recovery flag to disk. */
2193 	ext4_commit_super(sb, es, 1);
2194 
2195 	return 0;
2196 }
2197 
2198 static void ext4_commit_super (struct super_block * sb,
2199 			       struct ext4_super_block * es,
2200 			       int sync)
2201 {
2202 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2203 
2204 	if (!sbh)
2205 		return;
2206 	es->s_wtime = cpu_to_le32(get_seconds());
2207 	ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2208 	es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2209 	BUFFER_TRACE(sbh, "marking dirty");
2210 	mark_buffer_dirty(sbh);
2211 	if (sync)
2212 		sync_dirty_buffer(sbh);
2213 }
2214 
2215 
2216 /*
2217  * Have we just finished recovery?  If so, and if we are mounting (or
2218  * remounting) the filesystem readonly, then we will end up with a
2219  * consistent fs on disk.  Record that fact.
2220  */
2221 static void ext4_mark_recovery_complete(struct super_block * sb,
2222 					struct ext4_super_block * es)
2223 {
2224 	journal_t *journal = EXT4_SB(sb)->s_journal;
2225 
2226 	jbd2_journal_lock_updates(journal);
2227 	jbd2_journal_flush(journal);
2228 	lock_super(sb);
2229 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2230 	    sb->s_flags & MS_RDONLY) {
2231 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2232 		sb->s_dirt = 0;
2233 		ext4_commit_super(sb, es, 1);
2234 	}
2235 	unlock_super(sb);
2236 	jbd2_journal_unlock_updates(journal);
2237 }
2238 
2239 /*
2240  * If we are mounting (or read-write remounting) a filesystem whose journal
2241  * has recorded an error from a previous lifetime, move that error to the
2242  * main filesystem now.
2243  */
2244 static void ext4_clear_journal_err(struct super_block * sb,
2245 				   struct ext4_super_block * es)
2246 {
2247 	journal_t *journal;
2248 	int j_errno;
2249 	const char *errstr;
2250 
2251 	journal = EXT4_SB(sb)->s_journal;
2252 
2253 	/*
2254 	 * Now check for any error status which may have been recorded in the
2255 	 * journal by a prior ext4_error() or ext4_abort()
2256 	 */
2257 
2258 	j_errno = jbd2_journal_errno(journal);
2259 	if (j_errno) {
2260 		char nbuf[16];
2261 
2262 		errstr = ext4_decode_error(sb, j_errno, nbuf);
2263 		ext4_warning(sb, __FUNCTION__, "Filesystem error recorded "
2264 			     "from previous mount: %s", errstr);
2265 		ext4_warning(sb, __FUNCTION__, "Marking fs in need of "
2266 			     "filesystem check.");
2267 
2268 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2269 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2270 		ext4_commit_super (sb, es, 1);
2271 
2272 		jbd2_journal_clear_err(journal);
2273 	}
2274 }
2275 
2276 /*
2277  * Force the running and committing transactions to commit,
2278  * and wait on the commit.
2279  */
2280 int ext4_force_commit(struct super_block *sb)
2281 {
2282 	journal_t *journal;
2283 	int ret;
2284 
2285 	if (sb->s_flags & MS_RDONLY)
2286 		return 0;
2287 
2288 	journal = EXT4_SB(sb)->s_journal;
2289 	sb->s_dirt = 0;
2290 	ret = ext4_journal_force_commit(journal);
2291 	return ret;
2292 }
2293 
2294 /*
2295  * Ext4 always journals updates to the superblock itself, so we don't
2296  * have to propagate any other updates to the superblock on disk at this
2297  * point.  Just start an async writeback to get the buffers on their way
2298  * to the disk.
2299  *
2300  * This implicitly triggers the writebehind on sync().
2301  */
2302 
2303 static void ext4_write_super (struct super_block * sb)
2304 {
2305 	if (mutex_trylock(&sb->s_lock) != 0)
2306 		BUG();
2307 	sb->s_dirt = 0;
2308 }
2309 
2310 static int ext4_sync_fs(struct super_block *sb, int wait)
2311 {
2312 	tid_t target;
2313 
2314 	sb->s_dirt = 0;
2315 	if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2316 		if (wait)
2317 			jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2318 	}
2319 	return 0;
2320 }
2321 
2322 /*
2323  * LVM calls this function before a (read-only) snapshot is created.  This
2324  * gives us a chance to flush the journal completely and mark the fs clean.
2325  */
2326 static void ext4_write_super_lockfs(struct super_block *sb)
2327 {
2328 	sb->s_dirt = 0;
2329 
2330 	if (!(sb->s_flags & MS_RDONLY)) {
2331 		journal_t *journal = EXT4_SB(sb)->s_journal;
2332 
2333 		/* Now we set up the journal barrier. */
2334 		jbd2_journal_lock_updates(journal);
2335 		jbd2_journal_flush(journal);
2336 
2337 		/* Journal blocked and flushed, clear needs_recovery flag. */
2338 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2339 		ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2340 	}
2341 }
2342 
2343 /*
2344  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2345  * flag here, even though the filesystem is not technically dirty yet.
2346  */
2347 static void ext4_unlockfs(struct super_block *sb)
2348 {
2349 	if (!(sb->s_flags & MS_RDONLY)) {
2350 		lock_super(sb);
2351 		/* Reser the needs_recovery flag before the fs is unlocked. */
2352 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2353 		ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2354 		unlock_super(sb);
2355 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2356 	}
2357 }
2358 
2359 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2360 {
2361 	struct ext4_super_block * es;
2362 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2363 	ext4_fsblk_t n_blocks_count = 0;
2364 	unsigned long old_sb_flags;
2365 	struct ext4_mount_options old_opts;
2366 	int err;
2367 #ifdef CONFIG_QUOTA
2368 	int i;
2369 #endif
2370 
2371 	/* Store the original options */
2372 	old_sb_flags = sb->s_flags;
2373 	old_opts.s_mount_opt = sbi->s_mount_opt;
2374 	old_opts.s_resuid = sbi->s_resuid;
2375 	old_opts.s_resgid = sbi->s_resgid;
2376 	old_opts.s_commit_interval = sbi->s_commit_interval;
2377 #ifdef CONFIG_QUOTA
2378 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2379 	for (i = 0; i < MAXQUOTAS; i++)
2380 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2381 #endif
2382 
2383 	/*
2384 	 * Allow the "check" option to be passed as a remount option.
2385 	 */
2386 	if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2387 		err = -EINVAL;
2388 		goto restore_opts;
2389 	}
2390 
2391 	if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2392 		ext4_abort(sb, __FUNCTION__, "Abort forced by user");
2393 
2394 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2395 		((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2396 
2397 	es = sbi->s_es;
2398 
2399 	ext4_init_journal_params(sb, sbi->s_journal);
2400 
2401 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2402 		n_blocks_count > ext4_blocks_count(es)) {
2403 		if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2404 			err = -EROFS;
2405 			goto restore_opts;
2406 		}
2407 
2408 		if (*flags & MS_RDONLY) {
2409 			/*
2410 			 * First of all, the unconditional stuff we have to do
2411 			 * to disable replay of the journal when we next remount
2412 			 */
2413 			sb->s_flags |= MS_RDONLY;
2414 
2415 			/*
2416 			 * OK, test if we are remounting a valid rw partition
2417 			 * readonly, and if so set the rdonly flag and then
2418 			 * mark the partition as valid again.
2419 			 */
2420 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2421 			    (sbi->s_mount_state & EXT4_VALID_FS))
2422 				es->s_state = cpu_to_le16(sbi->s_mount_state);
2423 
2424 			/*
2425 			 * We have to unlock super so that we can wait for
2426 			 * transactions.
2427 			 */
2428 			unlock_super(sb);
2429 			ext4_mark_recovery_complete(sb, es);
2430 			lock_super(sb);
2431 		} else {
2432 			__le32 ret;
2433 			if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2434 					~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2435 				printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2436 				       "remount RDWR because of unsupported "
2437 				       "optional features (%x).\n",
2438 				       sb->s_id, le32_to_cpu(ret));
2439 				err = -EROFS;
2440 				goto restore_opts;
2441 			}
2442 
2443 			/*
2444 			 * If we have an unprocessed orphan list hanging
2445 			 * around from a previously readonly bdev mount,
2446 			 * require a full umount/remount for now.
2447 			 */
2448 			if (es->s_last_orphan) {
2449 				printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2450 				       "remount RDWR because of unprocessed "
2451 				       "orphan inode list.  Please "
2452 				       "umount/remount instead.\n",
2453 				       sb->s_id);
2454 				err = -EINVAL;
2455 				goto restore_opts;
2456 			}
2457 
2458 			/*
2459 			 * Mounting a RDONLY partition read-write, so reread
2460 			 * and store the current valid flag.  (It may have
2461 			 * been changed by e2fsck since we originally mounted
2462 			 * the partition.)
2463 			 */
2464 			ext4_clear_journal_err(sb, es);
2465 			sbi->s_mount_state = le16_to_cpu(es->s_state);
2466 			if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2467 				goto restore_opts;
2468 			if (!ext4_setup_super (sb, es, 0))
2469 				sb->s_flags &= ~MS_RDONLY;
2470 		}
2471 	}
2472 #ifdef CONFIG_QUOTA
2473 	/* Release old quota file names */
2474 	for (i = 0; i < MAXQUOTAS; i++)
2475 		if (old_opts.s_qf_names[i] &&
2476 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2477 			kfree(old_opts.s_qf_names[i]);
2478 #endif
2479 	return 0;
2480 restore_opts:
2481 	sb->s_flags = old_sb_flags;
2482 	sbi->s_mount_opt = old_opts.s_mount_opt;
2483 	sbi->s_resuid = old_opts.s_resuid;
2484 	sbi->s_resgid = old_opts.s_resgid;
2485 	sbi->s_commit_interval = old_opts.s_commit_interval;
2486 #ifdef CONFIG_QUOTA
2487 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2488 	for (i = 0; i < MAXQUOTAS; i++) {
2489 		if (sbi->s_qf_names[i] &&
2490 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2491 			kfree(sbi->s_qf_names[i]);
2492 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2493 	}
2494 #endif
2495 	return err;
2496 }
2497 
2498 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2499 {
2500 	struct super_block *sb = dentry->d_sb;
2501 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2502 	struct ext4_super_block *es = sbi->s_es;
2503 	u64 fsid;
2504 
2505 	if (test_opt(sb, MINIX_DF)) {
2506 		sbi->s_overhead_last = 0;
2507 	} else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
2508 		unsigned long ngroups = sbi->s_groups_count, i;
2509 		ext4_fsblk_t overhead = 0;
2510 		smp_rmb();
2511 
2512 		/*
2513 		 * Compute the overhead (FS structures).  This is constant
2514 		 * for a given filesystem unless the number of block groups
2515 		 * changes so we cache the previous value until it does.
2516 		 */
2517 
2518 		/*
2519 		 * All of the blocks before first_data_block are
2520 		 * overhead
2521 		 */
2522 		overhead = le32_to_cpu(es->s_first_data_block);
2523 
2524 		/*
2525 		 * Add the overhead attributed to the superblock and
2526 		 * block group descriptors.  If the sparse superblocks
2527 		 * feature is turned on, then not all groups have this.
2528 		 */
2529 		for (i = 0; i < ngroups; i++) {
2530 			overhead += ext4_bg_has_super(sb, i) +
2531 				ext4_bg_num_gdb(sb, i);
2532 			cond_resched();
2533 		}
2534 
2535 		/*
2536 		 * Every block group has an inode bitmap, a block
2537 		 * bitmap, and an inode table.
2538 		 */
2539 		overhead += ngroups * (2 + sbi->s_itb_per_group);
2540 		sbi->s_overhead_last = overhead;
2541 		smp_wmb();
2542 		sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
2543 	}
2544 
2545 	buf->f_type = EXT4_SUPER_MAGIC;
2546 	buf->f_bsize = sb->s_blocksize;
2547 	buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
2548 	buf->f_bfree = percpu_counter_sum(&sbi->s_freeblocks_counter);
2549 	es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
2550 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2551 	if (buf->f_bfree < ext4_r_blocks_count(es))
2552 		buf->f_bavail = 0;
2553 	buf->f_files = le32_to_cpu(es->s_inodes_count);
2554 	buf->f_ffree = percpu_counter_sum(&sbi->s_freeinodes_counter);
2555 	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
2556 	buf->f_namelen = EXT4_NAME_LEN;
2557 	fsid = le64_to_cpup((void *)es->s_uuid) ^
2558 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2559 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2560 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2561 	return 0;
2562 }
2563 
2564 /* Helper function for writing quotas on sync - we need to start transaction before quota file
2565  * is locked for write. Otherwise the are possible deadlocks:
2566  * Process 1                         Process 2
2567  * ext4_create()                     quota_sync()
2568  *   jbd2_journal_start()                   write_dquot()
2569  *   DQUOT_INIT()                        down(dqio_mutex)
2570  *     down(dqio_mutex)                    jbd2_journal_start()
2571  *
2572  */
2573 
2574 #ifdef CONFIG_QUOTA
2575 
2576 static inline struct inode *dquot_to_inode(struct dquot *dquot)
2577 {
2578 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
2579 }
2580 
2581 static int ext4_dquot_initialize(struct inode *inode, int type)
2582 {
2583 	handle_t *handle;
2584 	int ret, err;
2585 
2586 	/* We may create quota structure so we need to reserve enough blocks */
2587 	handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
2588 	if (IS_ERR(handle))
2589 		return PTR_ERR(handle);
2590 	ret = dquot_initialize(inode, type);
2591 	err = ext4_journal_stop(handle);
2592 	if (!ret)
2593 		ret = err;
2594 	return ret;
2595 }
2596 
2597 static int ext4_dquot_drop(struct inode *inode)
2598 {
2599 	handle_t *handle;
2600 	int ret, err;
2601 
2602 	/* We may delete quota structure so we need to reserve enough blocks */
2603 	handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
2604 	if (IS_ERR(handle))
2605 		return PTR_ERR(handle);
2606 	ret = dquot_drop(inode);
2607 	err = ext4_journal_stop(handle);
2608 	if (!ret)
2609 		ret = err;
2610 	return ret;
2611 }
2612 
2613 static int ext4_write_dquot(struct dquot *dquot)
2614 {
2615 	int ret, err;
2616 	handle_t *handle;
2617 	struct inode *inode;
2618 
2619 	inode = dquot_to_inode(dquot);
2620 	handle = ext4_journal_start(inode,
2621 					EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
2622 	if (IS_ERR(handle))
2623 		return PTR_ERR(handle);
2624 	ret = dquot_commit(dquot);
2625 	err = ext4_journal_stop(handle);
2626 	if (!ret)
2627 		ret = err;
2628 	return ret;
2629 }
2630 
2631 static int ext4_acquire_dquot(struct dquot *dquot)
2632 {
2633 	int ret, err;
2634 	handle_t *handle;
2635 
2636 	handle = ext4_journal_start(dquot_to_inode(dquot),
2637 					EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
2638 	if (IS_ERR(handle))
2639 		return PTR_ERR(handle);
2640 	ret = dquot_acquire(dquot);
2641 	err = ext4_journal_stop(handle);
2642 	if (!ret)
2643 		ret = err;
2644 	return ret;
2645 }
2646 
2647 static int ext4_release_dquot(struct dquot *dquot)
2648 {
2649 	int ret, err;
2650 	handle_t *handle;
2651 
2652 	handle = ext4_journal_start(dquot_to_inode(dquot),
2653 					EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
2654 	if (IS_ERR(handle))
2655 		return PTR_ERR(handle);
2656 	ret = dquot_release(dquot);
2657 	err = ext4_journal_stop(handle);
2658 	if (!ret)
2659 		ret = err;
2660 	return ret;
2661 }
2662 
2663 static int ext4_mark_dquot_dirty(struct dquot *dquot)
2664 {
2665 	/* Are we journalling quotas? */
2666 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
2667 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
2668 		dquot_mark_dquot_dirty(dquot);
2669 		return ext4_write_dquot(dquot);
2670 	} else {
2671 		return dquot_mark_dquot_dirty(dquot);
2672 	}
2673 }
2674 
2675 static int ext4_write_info(struct super_block *sb, int type)
2676 {
2677 	int ret, err;
2678 	handle_t *handle;
2679 
2680 	/* Data block + inode block */
2681 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
2682 	if (IS_ERR(handle))
2683 		return PTR_ERR(handle);
2684 	ret = dquot_commit_info(sb, type);
2685 	err = ext4_journal_stop(handle);
2686 	if (!ret)
2687 		ret = err;
2688 	return ret;
2689 }
2690 
2691 /*
2692  * Turn on quotas during mount time - we need to find
2693  * the quota file and such...
2694  */
2695 static int ext4_quota_on_mount(struct super_block *sb, int type)
2696 {
2697 	return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
2698 			EXT4_SB(sb)->s_jquota_fmt, type);
2699 }
2700 
2701 /*
2702  * Standard function to be called on quota_on
2703  */
2704 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
2705 			 char *path)
2706 {
2707 	int err;
2708 	struct nameidata nd;
2709 
2710 	if (!test_opt(sb, QUOTA))
2711 		return -EINVAL;
2712 	/* Not journalling quota? */
2713 	if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
2714 	    !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
2715 		return vfs_quota_on(sb, type, format_id, path);
2716 	err = path_lookup(path, LOOKUP_FOLLOW, &nd);
2717 	if (err)
2718 		return err;
2719 	/* Quotafile not on the same filesystem? */
2720 	if (nd.mnt->mnt_sb != sb) {
2721 		path_release(&nd);
2722 		return -EXDEV;
2723 	}
2724 	/* Quotafile not of fs root? */
2725 	if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
2726 		printk(KERN_WARNING
2727 			"EXT4-fs: Quota file not on filesystem root. "
2728 			"Journalled quota will not work.\n");
2729 	path_release(&nd);
2730 	return vfs_quota_on(sb, type, format_id, path);
2731 }
2732 
2733 /* Read data from quotafile - avoid pagecache and such because we cannot afford
2734  * acquiring the locks... As quota files are never truncated and quota code
2735  * itself serializes the operations (and noone else should touch the files)
2736  * we don't have to be afraid of races */
2737 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
2738 			       size_t len, loff_t off)
2739 {
2740 	struct inode *inode = sb_dqopt(sb)->files[type];
2741 	sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2742 	int err = 0;
2743 	int offset = off & (sb->s_blocksize - 1);
2744 	int tocopy;
2745 	size_t toread;
2746 	struct buffer_head *bh;
2747 	loff_t i_size = i_size_read(inode);
2748 
2749 	if (off > i_size)
2750 		return 0;
2751 	if (off+len > i_size)
2752 		len = i_size-off;
2753 	toread = len;
2754 	while (toread > 0) {
2755 		tocopy = sb->s_blocksize - offset < toread ?
2756 				sb->s_blocksize - offset : toread;
2757 		bh = ext4_bread(NULL, inode, blk, 0, &err);
2758 		if (err)
2759 			return err;
2760 		if (!bh)	/* A hole? */
2761 			memset(data, 0, tocopy);
2762 		else
2763 			memcpy(data, bh->b_data+offset, tocopy);
2764 		brelse(bh);
2765 		offset = 0;
2766 		toread -= tocopy;
2767 		data += tocopy;
2768 		blk++;
2769 	}
2770 	return len;
2771 }
2772 
2773 /* Write to quotafile (we know the transaction is already started and has
2774  * enough credits) */
2775 static ssize_t ext4_quota_write(struct super_block *sb, int type,
2776 				const char *data, size_t len, loff_t off)
2777 {
2778 	struct inode *inode = sb_dqopt(sb)->files[type];
2779 	sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2780 	int err = 0;
2781 	int offset = off & (sb->s_blocksize - 1);
2782 	int tocopy;
2783 	int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
2784 	size_t towrite = len;
2785 	struct buffer_head *bh;
2786 	handle_t *handle = journal_current_handle();
2787 
2788 	mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2789 	while (towrite > 0) {
2790 		tocopy = sb->s_blocksize - offset < towrite ?
2791 				sb->s_blocksize - offset : towrite;
2792 		bh = ext4_bread(handle, inode, blk, 1, &err);
2793 		if (!bh)
2794 			goto out;
2795 		if (journal_quota) {
2796 			err = ext4_journal_get_write_access(handle, bh);
2797 			if (err) {
2798 				brelse(bh);
2799 				goto out;
2800 			}
2801 		}
2802 		lock_buffer(bh);
2803 		memcpy(bh->b_data+offset, data, tocopy);
2804 		flush_dcache_page(bh->b_page);
2805 		unlock_buffer(bh);
2806 		if (journal_quota)
2807 			err = ext4_journal_dirty_metadata(handle, bh);
2808 		else {
2809 			/* Always do at least ordered writes for quotas */
2810 			err = ext4_journal_dirty_data(handle, bh);
2811 			mark_buffer_dirty(bh);
2812 		}
2813 		brelse(bh);
2814 		if (err)
2815 			goto out;
2816 		offset = 0;
2817 		towrite -= tocopy;
2818 		data += tocopy;
2819 		blk++;
2820 	}
2821 out:
2822 	if (len == towrite)
2823 		return err;
2824 	if (inode->i_size < off+len-towrite) {
2825 		i_size_write(inode, off+len-towrite);
2826 		EXT4_I(inode)->i_disksize = inode->i_size;
2827 	}
2828 	inode->i_version++;
2829 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2830 	ext4_mark_inode_dirty(handle, inode);
2831 	mutex_unlock(&inode->i_mutex);
2832 	return len - towrite;
2833 }
2834 
2835 #endif
2836 
2837 static int ext4_get_sb(struct file_system_type *fs_type,
2838 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
2839 {
2840 	return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
2841 }
2842 
2843 static struct file_system_type ext4dev_fs_type = {
2844 	.owner		= THIS_MODULE,
2845 	.name		= "ext4dev",
2846 	.get_sb		= ext4_get_sb,
2847 	.kill_sb	= kill_block_super,
2848 	.fs_flags	= FS_REQUIRES_DEV,
2849 };
2850 
2851 static int __init init_ext4_fs(void)
2852 {
2853 	int err = init_ext4_xattr();
2854 	if (err)
2855 		return err;
2856 	err = init_inodecache();
2857 	if (err)
2858 		goto out1;
2859 	err = register_filesystem(&ext4dev_fs_type);
2860 	if (err)
2861 		goto out;
2862 	return 0;
2863 out:
2864 	destroy_inodecache();
2865 out1:
2866 	exit_ext4_xattr();
2867 	return err;
2868 }
2869 
2870 static void __exit exit_ext4_fs(void)
2871 {
2872 	unregister_filesystem(&ext4dev_fs_type);
2873 	destroy_inodecache();
2874 	exit_ext4_xattr();
2875 }
2876 
2877 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
2878 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
2879 MODULE_LICENSE("GPL");
2880 module_init(init_ext4_fs)
2881 module_exit(exit_ext4_fs)
2882