xref: /linux/fs/ext4/super.c (revision eb2bce7f5e7ac1ca6da434461217fadf3c688d2c)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/jbd2.h>
24 #include <linux/ext4_fs.h>
25 #include <linux/ext4_jbd2.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/blkdev.h>
29 #include <linux/parser.h>
30 #include <linux/smp_lock.h>
31 #include <linux/buffer_head.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 
39 #include <asm/uaccess.h>
40 
41 #include "xattr.h"
42 #include "acl.h"
43 #include "namei.h"
44 
45 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
46 			     unsigned long journal_devnum);
47 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
48 			       unsigned int);
49 static void ext4_commit_super (struct super_block * sb,
50 			       struct ext4_super_block * es,
51 			       int sync);
52 static void ext4_mark_recovery_complete(struct super_block * sb,
53 					struct ext4_super_block * es);
54 static void ext4_clear_journal_err(struct super_block * sb,
55 				   struct ext4_super_block * es);
56 static int ext4_sync_fs(struct super_block *sb, int wait);
57 static const char *ext4_decode_error(struct super_block * sb, int errno,
58 				     char nbuf[16]);
59 static int ext4_remount (struct super_block * sb, int * flags, char * data);
60 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf);
61 static void ext4_unlockfs(struct super_block *sb);
62 static void ext4_write_super (struct super_block * sb);
63 static void ext4_write_super_lockfs(struct super_block *sb);
64 
65 
66 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
67 			       struct ext4_group_desc *bg)
68 {
69 	return le32_to_cpu(bg->bg_block_bitmap) |
70 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
71 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
72 }
73 
74 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
75 			       struct ext4_group_desc *bg)
76 {
77 	return le32_to_cpu(bg->bg_inode_bitmap) |
78 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
79 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
80 }
81 
82 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
83 			      struct ext4_group_desc *bg)
84 {
85 	return le32_to_cpu(bg->bg_inode_table) |
86 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
87 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
88 }
89 
90 void ext4_block_bitmap_set(struct super_block *sb,
91 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
92 {
93 	bg->bg_block_bitmap = cpu_to_le32((u32)blk);
94 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
95 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
96 }
97 
98 void ext4_inode_bitmap_set(struct super_block *sb,
99 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
100 {
101 	bg->bg_inode_bitmap  = cpu_to_le32((u32)blk);
102 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
103 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
104 }
105 
106 void ext4_inode_table_set(struct super_block *sb,
107 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
108 {
109 	bg->bg_inode_table = cpu_to_le32((u32)blk);
110 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
111 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
112 }
113 
114 /*
115  * Wrappers for jbd2_journal_start/end.
116  *
117  * The only special thing we need to do here is to make sure that all
118  * journal_end calls result in the superblock being marked dirty, so
119  * that sync() will call the filesystem's write_super callback if
120  * appropriate.
121  */
122 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
123 {
124 	journal_t *journal;
125 
126 	if (sb->s_flags & MS_RDONLY)
127 		return ERR_PTR(-EROFS);
128 
129 	/* Special case here: if the journal has aborted behind our
130 	 * backs (eg. EIO in the commit thread), then we still need to
131 	 * take the FS itself readonly cleanly. */
132 	journal = EXT4_SB(sb)->s_journal;
133 	if (is_journal_aborted(journal)) {
134 		ext4_abort(sb, __FUNCTION__,
135 			   "Detected aborted journal");
136 		return ERR_PTR(-EROFS);
137 	}
138 
139 	return jbd2_journal_start(journal, nblocks);
140 }
141 
142 /*
143  * The only special thing we need to do here is to make sure that all
144  * jbd2_journal_stop calls result in the superblock being marked dirty, so
145  * that sync() will call the filesystem's write_super callback if
146  * appropriate.
147  */
148 int __ext4_journal_stop(const char *where, handle_t *handle)
149 {
150 	struct super_block *sb;
151 	int err;
152 	int rc;
153 
154 	sb = handle->h_transaction->t_journal->j_private;
155 	err = handle->h_err;
156 	rc = jbd2_journal_stop(handle);
157 
158 	if (!err)
159 		err = rc;
160 	if (err)
161 		__ext4_std_error(sb, where, err);
162 	return err;
163 }
164 
165 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
166 		struct buffer_head *bh, handle_t *handle, int err)
167 {
168 	char nbuf[16];
169 	const char *errstr = ext4_decode_error(NULL, err, nbuf);
170 
171 	if (bh)
172 		BUFFER_TRACE(bh, "abort");
173 
174 	if (!handle->h_err)
175 		handle->h_err = err;
176 
177 	if (is_handle_aborted(handle))
178 		return;
179 
180 	printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
181 	       caller, errstr, err_fn);
182 
183 	jbd2_journal_abort_handle(handle);
184 }
185 
186 /* Deal with the reporting of failure conditions on a filesystem such as
187  * inconsistencies detected or read IO failures.
188  *
189  * On ext2, we can store the error state of the filesystem in the
190  * superblock.  That is not possible on ext4, because we may have other
191  * write ordering constraints on the superblock which prevent us from
192  * writing it out straight away; and given that the journal is about to
193  * be aborted, we can't rely on the current, or future, transactions to
194  * write out the superblock safely.
195  *
196  * We'll just use the jbd2_journal_abort() error code to record an error in
197  * the journal instead.  On recovery, the journal will compain about
198  * that error until we've noted it down and cleared it.
199  */
200 
201 static void ext4_handle_error(struct super_block *sb)
202 {
203 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
204 
205 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
206 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
207 
208 	if (sb->s_flags & MS_RDONLY)
209 		return;
210 
211 	if (!test_opt (sb, ERRORS_CONT)) {
212 		journal_t *journal = EXT4_SB(sb)->s_journal;
213 
214 		EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
215 		if (journal)
216 			jbd2_journal_abort(journal, -EIO);
217 	}
218 	if (test_opt (sb, ERRORS_RO)) {
219 		printk (KERN_CRIT "Remounting filesystem read-only\n");
220 		sb->s_flags |= MS_RDONLY;
221 	}
222 	ext4_commit_super(sb, es, 1);
223 	if (test_opt(sb, ERRORS_PANIC))
224 		panic("EXT4-fs (device %s): panic forced after error\n",
225 			sb->s_id);
226 }
227 
228 void ext4_error (struct super_block * sb, const char * function,
229 		 const char * fmt, ...)
230 {
231 	va_list args;
232 
233 	va_start(args, fmt);
234 	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
235 	vprintk(fmt, args);
236 	printk("\n");
237 	va_end(args);
238 
239 	ext4_handle_error(sb);
240 }
241 
242 static const char *ext4_decode_error(struct super_block * sb, int errno,
243 				     char nbuf[16])
244 {
245 	char *errstr = NULL;
246 
247 	switch (errno) {
248 	case -EIO:
249 		errstr = "IO failure";
250 		break;
251 	case -ENOMEM:
252 		errstr = "Out of memory";
253 		break;
254 	case -EROFS:
255 		if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
256 			errstr = "Journal has aborted";
257 		else
258 			errstr = "Readonly filesystem";
259 		break;
260 	default:
261 		/* If the caller passed in an extra buffer for unknown
262 		 * errors, textualise them now.  Else we just return
263 		 * NULL. */
264 		if (nbuf) {
265 			/* Check for truncated error codes... */
266 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
267 				errstr = nbuf;
268 		}
269 		break;
270 	}
271 
272 	return errstr;
273 }
274 
275 /* __ext4_std_error decodes expected errors from journaling functions
276  * automatically and invokes the appropriate error response.  */
277 
278 void __ext4_std_error (struct super_block * sb, const char * function,
279 		       int errno)
280 {
281 	char nbuf[16];
282 	const char *errstr;
283 
284 	/* Special case: if the error is EROFS, and we're not already
285 	 * inside a transaction, then there's really no point in logging
286 	 * an error. */
287 	if (errno == -EROFS && journal_current_handle() == NULL &&
288 	    (sb->s_flags & MS_RDONLY))
289 		return;
290 
291 	errstr = ext4_decode_error(sb, errno, nbuf);
292 	printk (KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
293 		sb->s_id, function, errstr);
294 
295 	ext4_handle_error(sb);
296 }
297 
298 /*
299  * ext4_abort is a much stronger failure handler than ext4_error.  The
300  * abort function may be used to deal with unrecoverable failures such
301  * as journal IO errors or ENOMEM at a critical moment in log management.
302  *
303  * We unconditionally force the filesystem into an ABORT|READONLY state,
304  * unless the error response on the fs has been set to panic in which
305  * case we take the easy way out and panic immediately.
306  */
307 
308 void ext4_abort (struct super_block * sb, const char * function,
309 		 const char * fmt, ...)
310 {
311 	va_list args;
312 
313 	printk (KERN_CRIT "ext4_abort called.\n");
314 
315 	va_start(args, fmt);
316 	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ",sb->s_id, function);
317 	vprintk(fmt, args);
318 	printk("\n");
319 	va_end(args);
320 
321 	if (test_opt(sb, ERRORS_PANIC))
322 		panic("EXT4-fs panic from previous error\n");
323 
324 	if (sb->s_flags & MS_RDONLY)
325 		return;
326 
327 	printk(KERN_CRIT "Remounting filesystem read-only\n");
328 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
329 	sb->s_flags |= MS_RDONLY;
330 	EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT;
331 	jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
332 }
333 
334 void ext4_warning (struct super_block * sb, const char * function,
335 		   const char * fmt, ...)
336 {
337 	va_list args;
338 
339 	va_start(args, fmt);
340 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
341 	       sb->s_id, function);
342 	vprintk(fmt, args);
343 	printk("\n");
344 	va_end(args);
345 }
346 
347 void ext4_update_dynamic_rev(struct super_block *sb)
348 {
349 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
350 
351 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
352 		return;
353 
354 	ext4_warning(sb, __FUNCTION__,
355 		     "updating to rev %d because of new feature flag, "
356 		     "running e2fsck is recommended",
357 		     EXT4_DYNAMIC_REV);
358 
359 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
360 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
361 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
362 	/* leave es->s_feature_*compat flags alone */
363 	/* es->s_uuid will be set by e2fsck if empty */
364 
365 	/*
366 	 * The rest of the superblock fields should be zero, and if not it
367 	 * means they are likely already in use, so leave them alone.  We
368 	 * can leave it up to e2fsck to clean up any inconsistencies there.
369 	 */
370 }
371 
372 /*
373  * Open the external journal device
374  */
375 static struct block_device *ext4_blkdev_get(dev_t dev)
376 {
377 	struct block_device *bdev;
378 	char b[BDEVNAME_SIZE];
379 
380 	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
381 	if (IS_ERR(bdev))
382 		goto fail;
383 	return bdev;
384 
385 fail:
386 	printk(KERN_ERR "EXT4: failed to open journal device %s: %ld\n",
387 			__bdevname(dev, b), PTR_ERR(bdev));
388 	return NULL;
389 }
390 
391 /*
392  * Release the journal device
393  */
394 static int ext4_blkdev_put(struct block_device *bdev)
395 {
396 	bd_release(bdev);
397 	return blkdev_put(bdev);
398 }
399 
400 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
401 {
402 	struct block_device *bdev;
403 	int ret = -ENODEV;
404 
405 	bdev = sbi->journal_bdev;
406 	if (bdev) {
407 		ret = ext4_blkdev_put(bdev);
408 		sbi->journal_bdev = NULL;
409 	}
410 	return ret;
411 }
412 
413 static inline struct inode *orphan_list_entry(struct list_head *l)
414 {
415 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
416 }
417 
418 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
419 {
420 	struct list_head *l;
421 
422 	printk(KERN_ERR "sb orphan head is %d\n",
423 	       le32_to_cpu(sbi->s_es->s_last_orphan));
424 
425 	printk(KERN_ERR "sb_info orphan list:\n");
426 	list_for_each(l, &sbi->s_orphan) {
427 		struct inode *inode = orphan_list_entry(l);
428 		printk(KERN_ERR "  "
429 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
430 		       inode->i_sb->s_id, inode->i_ino, inode,
431 		       inode->i_mode, inode->i_nlink,
432 		       NEXT_ORPHAN(inode));
433 	}
434 }
435 
436 static void ext4_put_super (struct super_block * sb)
437 {
438 	struct ext4_sb_info *sbi = EXT4_SB(sb);
439 	struct ext4_super_block *es = sbi->s_es;
440 	int i;
441 
442 	ext4_ext_release(sb);
443 	ext4_xattr_put_super(sb);
444 	jbd2_journal_destroy(sbi->s_journal);
445 	if (!(sb->s_flags & MS_RDONLY)) {
446 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
447 		es->s_state = cpu_to_le16(sbi->s_mount_state);
448 		BUFFER_TRACE(sbi->s_sbh, "marking dirty");
449 		mark_buffer_dirty(sbi->s_sbh);
450 		ext4_commit_super(sb, es, 1);
451 	}
452 
453 	for (i = 0; i < sbi->s_gdb_count; i++)
454 		brelse(sbi->s_group_desc[i]);
455 	kfree(sbi->s_group_desc);
456 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
457 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
458 	percpu_counter_destroy(&sbi->s_dirs_counter);
459 	brelse(sbi->s_sbh);
460 #ifdef CONFIG_QUOTA
461 	for (i = 0; i < MAXQUOTAS; i++)
462 		kfree(sbi->s_qf_names[i]);
463 #endif
464 
465 	/* Debugging code just in case the in-memory inode orphan list
466 	 * isn't empty.  The on-disk one can be non-empty if we've
467 	 * detected an error and taken the fs readonly, but the
468 	 * in-memory list had better be clean by this point. */
469 	if (!list_empty(&sbi->s_orphan))
470 		dump_orphan_list(sb, sbi);
471 	J_ASSERT(list_empty(&sbi->s_orphan));
472 
473 	invalidate_bdev(sb->s_bdev);
474 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
475 		/*
476 		 * Invalidate the journal device's buffers.  We don't want them
477 		 * floating about in memory - the physical journal device may
478 		 * hotswapped, and it breaks the `ro-after' testing code.
479 		 */
480 		sync_blockdev(sbi->journal_bdev);
481 		invalidate_bdev(sbi->journal_bdev);
482 		ext4_blkdev_remove(sbi);
483 	}
484 	sb->s_fs_info = NULL;
485 	kfree(sbi);
486 	return;
487 }
488 
489 static struct kmem_cache *ext4_inode_cachep;
490 
491 /*
492  * Called inside transaction, so use GFP_NOFS
493  */
494 static struct inode *ext4_alloc_inode(struct super_block *sb)
495 {
496 	struct ext4_inode_info *ei;
497 
498 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
499 	if (!ei)
500 		return NULL;
501 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
502 	ei->i_acl = EXT4_ACL_NOT_CACHED;
503 	ei->i_default_acl = EXT4_ACL_NOT_CACHED;
504 #endif
505 	ei->i_block_alloc_info = NULL;
506 	ei->vfs_inode.i_version = 1;
507 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
508 	return &ei->vfs_inode;
509 }
510 
511 static void ext4_destroy_inode(struct inode *inode)
512 {
513 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
514 }
515 
516 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
517 {
518 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
519 
520 	if (flags & SLAB_CTOR_CONSTRUCTOR) {
521 		INIT_LIST_HEAD(&ei->i_orphan);
522 #ifdef CONFIG_EXT4DEV_FS_XATTR
523 		init_rwsem(&ei->xattr_sem);
524 #endif
525 		mutex_init(&ei->truncate_mutex);
526 		inode_init_once(&ei->vfs_inode);
527 	}
528 }
529 
530 static int init_inodecache(void)
531 {
532 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
533 					     sizeof(struct ext4_inode_info),
534 					     0, (SLAB_RECLAIM_ACCOUNT|
535 						SLAB_MEM_SPREAD),
536 					     init_once, NULL);
537 	if (ext4_inode_cachep == NULL)
538 		return -ENOMEM;
539 	return 0;
540 }
541 
542 static void destroy_inodecache(void)
543 {
544 	kmem_cache_destroy(ext4_inode_cachep);
545 }
546 
547 static void ext4_clear_inode(struct inode *inode)
548 {
549 	struct ext4_block_alloc_info *rsv = EXT4_I(inode)->i_block_alloc_info;
550 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
551 	if (EXT4_I(inode)->i_acl &&
552 			EXT4_I(inode)->i_acl != EXT4_ACL_NOT_CACHED) {
553 		posix_acl_release(EXT4_I(inode)->i_acl);
554 		EXT4_I(inode)->i_acl = EXT4_ACL_NOT_CACHED;
555 	}
556 	if (EXT4_I(inode)->i_default_acl &&
557 			EXT4_I(inode)->i_default_acl != EXT4_ACL_NOT_CACHED) {
558 		posix_acl_release(EXT4_I(inode)->i_default_acl);
559 		EXT4_I(inode)->i_default_acl = EXT4_ACL_NOT_CACHED;
560 	}
561 #endif
562 	ext4_discard_reservation(inode);
563 	EXT4_I(inode)->i_block_alloc_info = NULL;
564 	if (unlikely(rsv))
565 		kfree(rsv);
566 }
567 
568 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
569 {
570 #if defined(CONFIG_QUOTA)
571 	struct ext4_sb_info *sbi = EXT4_SB(sb);
572 
573 	if (sbi->s_jquota_fmt)
574 		seq_printf(seq, ",jqfmt=%s",
575 		(sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold": "vfsv0");
576 
577 	if (sbi->s_qf_names[USRQUOTA])
578 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
579 
580 	if (sbi->s_qf_names[GRPQUOTA])
581 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
582 
583 	if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
584 		seq_puts(seq, ",usrquota");
585 
586 	if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
587 		seq_puts(seq, ",grpquota");
588 #endif
589 }
590 
591 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
592 {
593 	struct super_block *sb = vfs->mnt_sb;
594 
595 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
596 		seq_puts(seq, ",data=journal");
597 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
598 		seq_puts(seq, ",data=ordered");
599 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
600 		seq_puts(seq, ",data=writeback");
601 
602 	ext4_show_quota_options(seq, sb);
603 
604 	return 0;
605 }
606 
607 
608 static struct dentry *ext4_get_dentry(struct super_block *sb, void *vobjp)
609 {
610 	__u32 *objp = vobjp;
611 	unsigned long ino = objp[0];
612 	__u32 generation = objp[1];
613 	struct inode *inode;
614 	struct dentry *result;
615 
616 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
617 		return ERR_PTR(-ESTALE);
618 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
619 		return ERR_PTR(-ESTALE);
620 
621 	/* iget isn't really right if the inode is currently unallocated!!
622 	 *
623 	 * ext4_read_inode will return a bad_inode if the inode had been
624 	 * deleted, so we should be safe.
625 	 *
626 	 * Currently we don't know the generation for parent directory, so
627 	 * a generation of 0 means "accept any"
628 	 */
629 	inode = iget(sb, ino);
630 	if (inode == NULL)
631 		return ERR_PTR(-ENOMEM);
632 	if (is_bad_inode(inode) ||
633 	    (generation && inode->i_generation != generation)) {
634 		iput(inode);
635 		return ERR_PTR(-ESTALE);
636 	}
637 	/* now to find a dentry.
638 	 * If possible, get a well-connected one
639 	 */
640 	result = d_alloc_anon(inode);
641 	if (!result) {
642 		iput(inode);
643 		return ERR_PTR(-ENOMEM);
644 	}
645 	return result;
646 }
647 
648 #ifdef CONFIG_QUOTA
649 #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group")
650 #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
651 
652 static int ext4_dquot_initialize(struct inode *inode, int type);
653 static int ext4_dquot_drop(struct inode *inode);
654 static int ext4_write_dquot(struct dquot *dquot);
655 static int ext4_acquire_dquot(struct dquot *dquot);
656 static int ext4_release_dquot(struct dquot *dquot);
657 static int ext4_mark_dquot_dirty(struct dquot *dquot);
658 static int ext4_write_info(struct super_block *sb, int type);
659 static int ext4_quota_on(struct super_block *sb, int type, int format_id, char *path);
660 static int ext4_quota_on_mount(struct super_block *sb, int type);
661 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
662 			       size_t len, loff_t off);
663 static ssize_t ext4_quota_write(struct super_block *sb, int type,
664 				const char *data, size_t len, loff_t off);
665 
666 static struct dquot_operations ext4_quota_operations = {
667 	.initialize	= ext4_dquot_initialize,
668 	.drop		= ext4_dquot_drop,
669 	.alloc_space	= dquot_alloc_space,
670 	.alloc_inode	= dquot_alloc_inode,
671 	.free_space	= dquot_free_space,
672 	.free_inode	= dquot_free_inode,
673 	.transfer	= dquot_transfer,
674 	.write_dquot	= ext4_write_dquot,
675 	.acquire_dquot	= ext4_acquire_dquot,
676 	.release_dquot	= ext4_release_dquot,
677 	.mark_dirty	= ext4_mark_dquot_dirty,
678 	.write_info	= ext4_write_info
679 };
680 
681 static struct quotactl_ops ext4_qctl_operations = {
682 	.quota_on	= ext4_quota_on,
683 	.quota_off	= vfs_quota_off,
684 	.quota_sync	= vfs_quota_sync,
685 	.get_info	= vfs_get_dqinfo,
686 	.set_info	= vfs_set_dqinfo,
687 	.get_dqblk	= vfs_get_dqblk,
688 	.set_dqblk	= vfs_set_dqblk
689 };
690 #endif
691 
692 static const struct super_operations ext4_sops = {
693 	.alloc_inode	= ext4_alloc_inode,
694 	.destroy_inode	= ext4_destroy_inode,
695 	.read_inode	= ext4_read_inode,
696 	.write_inode	= ext4_write_inode,
697 	.dirty_inode	= ext4_dirty_inode,
698 	.delete_inode	= ext4_delete_inode,
699 	.put_super	= ext4_put_super,
700 	.write_super	= ext4_write_super,
701 	.sync_fs	= ext4_sync_fs,
702 	.write_super_lockfs = ext4_write_super_lockfs,
703 	.unlockfs	= ext4_unlockfs,
704 	.statfs		= ext4_statfs,
705 	.remount_fs	= ext4_remount,
706 	.clear_inode	= ext4_clear_inode,
707 	.show_options	= ext4_show_options,
708 #ifdef CONFIG_QUOTA
709 	.quota_read	= ext4_quota_read,
710 	.quota_write	= ext4_quota_write,
711 #endif
712 };
713 
714 static struct export_operations ext4_export_ops = {
715 	.get_parent = ext4_get_parent,
716 	.get_dentry = ext4_get_dentry,
717 };
718 
719 enum {
720 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
721 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
722 	Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov,
723 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
724 	Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
725 	Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
726 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
727 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
728 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
729 	Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
730 	Opt_grpquota, Opt_extents,
731 };
732 
733 static match_table_t tokens = {
734 	{Opt_bsd_df, "bsddf"},
735 	{Opt_minix_df, "minixdf"},
736 	{Opt_grpid, "grpid"},
737 	{Opt_grpid, "bsdgroups"},
738 	{Opt_nogrpid, "nogrpid"},
739 	{Opt_nogrpid, "sysvgroups"},
740 	{Opt_resgid, "resgid=%u"},
741 	{Opt_resuid, "resuid=%u"},
742 	{Opt_sb, "sb=%u"},
743 	{Opt_err_cont, "errors=continue"},
744 	{Opt_err_panic, "errors=panic"},
745 	{Opt_err_ro, "errors=remount-ro"},
746 	{Opt_nouid32, "nouid32"},
747 	{Opt_nocheck, "nocheck"},
748 	{Opt_nocheck, "check=none"},
749 	{Opt_debug, "debug"},
750 	{Opt_oldalloc, "oldalloc"},
751 	{Opt_orlov, "orlov"},
752 	{Opt_user_xattr, "user_xattr"},
753 	{Opt_nouser_xattr, "nouser_xattr"},
754 	{Opt_acl, "acl"},
755 	{Opt_noacl, "noacl"},
756 	{Opt_reservation, "reservation"},
757 	{Opt_noreservation, "noreservation"},
758 	{Opt_noload, "noload"},
759 	{Opt_nobh, "nobh"},
760 	{Opt_bh, "bh"},
761 	{Opt_commit, "commit=%u"},
762 	{Opt_journal_update, "journal=update"},
763 	{Opt_journal_inum, "journal=%u"},
764 	{Opt_journal_dev, "journal_dev=%u"},
765 	{Opt_abort, "abort"},
766 	{Opt_data_journal, "data=journal"},
767 	{Opt_data_ordered, "data=ordered"},
768 	{Opt_data_writeback, "data=writeback"},
769 	{Opt_offusrjquota, "usrjquota="},
770 	{Opt_usrjquota, "usrjquota=%s"},
771 	{Opt_offgrpjquota, "grpjquota="},
772 	{Opt_grpjquota, "grpjquota=%s"},
773 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
774 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
775 	{Opt_grpquota, "grpquota"},
776 	{Opt_noquota, "noquota"},
777 	{Opt_quota, "quota"},
778 	{Opt_usrquota, "usrquota"},
779 	{Opt_barrier, "barrier=%u"},
780 	{Opt_extents, "extents"},
781 	{Opt_err, NULL},
782 	{Opt_resize, "resize"},
783 };
784 
785 static ext4_fsblk_t get_sb_block(void **data)
786 {
787 	ext4_fsblk_t	sb_block;
788 	char		*options = (char *) *data;
789 
790 	if (!options || strncmp(options, "sb=", 3) != 0)
791 		return 1;	/* Default location */
792 	options += 3;
793 	/*todo: use simple_strtoll with >32bit ext4 */
794 	sb_block = simple_strtoul(options, &options, 0);
795 	if (*options && *options != ',') {
796 		printk("EXT4-fs: Invalid sb specification: %s\n",
797 		       (char *) *data);
798 		return 1;
799 	}
800 	if (*options == ',')
801 		options++;
802 	*data = (void *) options;
803 	return sb_block;
804 }
805 
806 static int parse_options (char *options, struct super_block *sb,
807 			  unsigned int *inum, unsigned long *journal_devnum,
808 			  ext4_fsblk_t *n_blocks_count, int is_remount)
809 {
810 	struct ext4_sb_info *sbi = EXT4_SB(sb);
811 	char * p;
812 	substring_t args[MAX_OPT_ARGS];
813 	int data_opt = 0;
814 	int option;
815 #ifdef CONFIG_QUOTA
816 	int qtype;
817 	char *qname;
818 #endif
819 
820 	if (!options)
821 		return 1;
822 
823 	while ((p = strsep (&options, ",")) != NULL) {
824 		int token;
825 		if (!*p)
826 			continue;
827 
828 		token = match_token(p, tokens, args);
829 		switch (token) {
830 		case Opt_bsd_df:
831 			clear_opt (sbi->s_mount_opt, MINIX_DF);
832 			break;
833 		case Opt_minix_df:
834 			set_opt (sbi->s_mount_opt, MINIX_DF);
835 			break;
836 		case Opt_grpid:
837 			set_opt (sbi->s_mount_opt, GRPID);
838 			break;
839 		case Opt_nogrpid:
840 			clear_opt (sbi->s_mount_opt, GRPID);
841 			break;
842 		case Opt_resuid:
843 			if (match_int(&args[0], &option))
844 				return 0;
845 			sbi->s_resuid = option;
846 			break;
847 		case Opt_resgid:
848 			if (match_int(&args[0], &option))
849 				return 0;
850 			sbi->s_resgid = option;
851 			break;
852 		case Opt_sb:
853 			/* handled by get_sb_block() instead of here */
854 			/* *sb_block = match_int(&args[0]); */
855 			break;
856 		case Opt_err_panic:
857 			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
858 			clear_opt (sbi->s_mount_opt, ERRORS_RO);
859 			set_opt (sbi->s_mount_opt, ERRORS_PANIC);
860 			break;
861 		case Opt_err_ro:
862 			clear_opt (sbi->s_mount_opt, ERRORS_CONT);
863 			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
864 			set_opt (sbi->s_mount_opt, ERRORS_RO);
865 			break;
866 		case Opt_err_cont:
867 			clear_opt (sbi->s_mount_opt, ERRORS_RO);
868 			clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
869 			set_opt (sbi->s_mount_opt, ERRORS_CONT);
870 			break;
871 		case Opt_nouid32:
872 			set_opt (sbi->s_mount_opt, NO_UID32);
873 			break;
874 		case Opt_nocheck:
875 			clear_opt (sbi->s_mount_opt, CHECK);
876 			break;
877 		case Opt_debug:
878 			set_opt (sbi->s_mount_opt, DEBUG);
879 			break;
880 		case Opt_oldalloc:
881 			set_opt (sbi->s_mount_opt, OLDALLOC);
882 			break;
883 		case Opt_orlov:
884 			clear_opt (sbi->s_mount_opt, OLDALLOC);
885 			break;
886 #ifdef CONFIG_EXT4DEV_FS_XATTR
887 		case Opt_user_xattr:
888 			set_opt (sbi->s_mount_opt, XATTR_USER);
889 			break;
890 		case Opt_nouser_xattr:
891 			clear_opt (sbi->s_mount_opt, XATTR_USER);
892 			break;
893 #else
894 		case Opt_user_xattr:
895 		case Opt_nouser_xattr:
896 			printk("EXT4 (no)user_xattr options not supported\n");
897 			break;
898 #endif
899 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
900 		case Opt_acl:
901 			set_opt(sbi->s_mount_opt, POSIX_ACL);
902 			break;
903 		case Opt_noacl:
904 			clear_opt(sbi->s_mount_opt, POSIX_ACL);
905 			break;
906 #else
907 		case Opt_acl:
908 		case Opt_noacl:
909 			printk("EXT4 (no)acl options not supported\n");
910 			break;
911 #endif
912 		case Opt_reservation:
913 			set_opt(sbi->s_mount_opt, RESERVATION);
914 			break;
915 		case Opt_noreservation:
916 			clear_opt(sbi->s_mount_opt, RESERVATION);
917 			break;
918 		case Opt_journal_update:
919 			/* @@@ FIXME */
920 			/* Eventually we will want to be able to create
921 			   a journal file here.  For now, only allow the
922 			   user to specify an existing inode to be the
923 			   journal file. */
924 			if (is_remount) {
925 				printk(KERN_ERR "EXT4-fs: cannot specify "
926 				       "journal on remount\n");
927 				return 0;
928 			}
929 			set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
930 			break;
931 		case Opt_journal_inum:
932 			if (is_remount) {
933 				printk(KERN_ERR "EXT4-fs: cannot specify "
934 				       "journal on remount\n");
935 				return 0;
936 			}
937 			if (match_int(&args[0], &option))
938 				return 0;
939 			*inum = option;
940 			break;
941 		case Opt_journal_dev:
942 			if (is_remount) {
943 				printk(KERN_ERR "EXT4-fs: cannot specify "
944 				       "journal on remount\n");
945 				return 0;
946 			}
947 			if (match_int(&args[0], &option))
948 				return 0;
949 			*journal_devnum = option;
950 			break;
951 		case Opt_noload:
952 			set_opt (sbi->s_mount_opt, NOLOAD);
953 			break;
954 		case Opt_commit:
955 			if (match_int(&args[0], &option))
956 				return 0;
957 			if (option < 0)
958 				return 0;
959 			if (option == 0)
960 				option = JBD_DEFAULT_MAX_COMMIT_AGE;
961 			sbi->s_commit_interval = HZ * option;
962 			break;
963 		case Opt_data_journal:
964 			data_opt = EXT4_MOUNT_JOURNAL_DATA;
965 			goto datacheck;
966 		case Opt_data_ordered:
967 			data_opt = EXT4_MOUNT_ORDERED_DATA;
968 			goto datacheck;
969 		case Opt_data_writeback:
970 			data_opt = EXT4_MOUNT_WRITEBACK_DATA;
971 		datacheck:
972 			if (is_remount) {
973 				if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
974 						!= data_opt) {
975 					printk(KERN_ERR
976 						"EXT4-fs: cannot change data "
977 						"mode on remount\n");
978 					return 0;
979 				}
980 			} else {
981 				sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
982 				sbi->s_mount_opt |= data_opt;
983 			}
984 			break;
985 #ifdef CONFIG_QUOTA
986 		case Opt_usrjquota:
987 			qtype = USRQUOTA;
988 			goto set_qf_name;
989 		case Opt_grpjquota:
990 			qtype = GRPQUOTA;
991 set_qf_name:
992 			if (sb_any_quota_enabled(sb)) {
993 				printk(KERN_ERR
994 					"EXT4-fs: Cannot change journalled "
995 					"quota options when quota turned on.\n");
996 				return 0;
997 			}
998 			qname = match_strdup(&args[0]);
999 			if (!qname) {
1000 				printk(KERN_ERR
1001 					"EXT4-fs: not enough memory for "
1002 					"storing quotafile name.\n");
1003 				return 0;
1004 			}
1005 			if (sbi->s_qf_names[qtype] &&
1006 			    strcmp(sbi->s_qf_names[qtype], qname)) {
1007 				printk(KERN_ERR
1008 					"EXT4-fs: %s quota file already "
1009 					"specified.\n", QTYPE2NAME(qtype));
1010 				kfree(qname);
1011 				return 0;
1012 			}
1013 			sbi->s_qf_names[qtype] = qname;
1014 			if (strchr(sbi->s_qf_names[qtype], '/')) {
1015 				printk(KERN_ERR
1016 					"EXT4-fs: quotafile must be on "
1017 					"filesystem root.\n");
1018 				kfree(sbi->s_qf_names[qtype]);
1019 				sbi->s_qf_names[qtype] = NULL;
1020 				return 0;
1021 			}
1022 			set_opt(sbi->s_mount_opt, QUOTA);
1023 			break;
1024 		case Opt_offusrjquota:
1025 			qtype = USRQUOTA;
1026 			goto clear_qf_name;
1027 		case Opt_offgrpjquota:
1028 			qtype = GRPQUOTA;
1029 clear_qf_name:
1030 			if (sb_any_quota_enabled(sb)) {
1031 				printk(KERN_ERR "EXT4-fs: Cannot change "
1032 					"journalled quota options when "
1033 					"quota turned on.\n");
1034 				return 0;
1035 			}
1036 			/*
1037 			 * The space will be released later when all options
1038 			 * are confirmed to be correct
1039 			 */
1040 			sbi->s_qf_names[qtype] = NULL;
1041 			break;
1042 		case Opt_jqfmt_vfsold:
1043 			sbi->s_jquota_fmt = QFMT_VFS_OLD;
1044 			break;
1045 		case Opt_jqfmt_vfsv0:
1046 			sbi->s_jquota_fmt = QFMT_VFS_V0;
1047 			break;
1048 		case Opt_quota:
1049 		case Opt_usrquota:
1050 			set_opt(sbi->s_mount_opt, QUOTA);
1051 			set_opt(sbi->s_mount_opt, USRQUOTA);
1052 			break;
1053 		case Opt_grpquota:
1054 			set_opt(sbi->s_mount_opt, QUOTA);
1055 			set_opt(sbi->s_mount_opt, GRPQUOTA);
1056 			break;
1057 		case Opt_noquota:
1058 			if (sb_any_quota_enabled(sb)) {
1059 				printk(KERN_ERR "EXT4-fs: Cannot change quota "
1060 					"options when quota turned on.\n");
1061 				return 0;
1062 			}
1063 			clear_opt(sbi->s_mount_opt, QUOTA);
1064 			clear_opt(sbi->s_mount_opt, USRQUOTA);
1065 			clear_opt(sbi->s_mount_opt, GRPQUOTA);
1066 			break;
1067 #else
1068 		case Opt_quota:
1069 		case Opt_usrquota:
1070 		case Opt_grpquota:
1071 		case Opt_usrjquota:
1072 		case Opt_grpjquota:
1073 		case Opt_offusrjquota:
1074 		case Opt_offgrpjquota:
1075 		case Opt_jqfmt_vfsold:
1076 		case Opt_jqfmt_vfsv0:
1077 			printk(KERN_ERR
1078 				"EXT4-fs: journalled quota options not "
1079 				"supported.\n");
1080 			break;
1081 		case Opt_noquota:
1082 			break;
1083 #endif
1084 		case Opt_abort:
1085 			set_opt(sbi->s_mount_opt, ABORT);
1086 			break;
1087 		case Opt_barrier:
1088 			if (match_int(&args[0], &option))
1089 				return 0;
1090 			if (option)
1091 				set_opt(sbi->s_mount_opt, BARRIER);
1092 			else
1093 				clear_opt(sbi->s_mount_opt, BARRIER);
1094 			break;
1095 		case Opt_ignore:
1096 			break;
1097 		case Opt_resize:
1098 			if (!is_remount) {
1099 				printk("EXT4-fs: resize option only available "
1100 					"for remount\n");
1101 				return 0;
1102 			}
1103 			if (match_int(&args[0], &option) != 0)
1104 				return 0;
1105 			*n_blocks_count = option;
1106 			break;
1107 		case Opt_nobh:
1108 			set_opt(sbi->s_mount_opt, NOBH);
1109 			break;
1110 		case Opt_bh:
1111 			clear_opt(sbi->s_mount_opt, NOBH);
1112 			break;
1113 		case Opt_extents:
1114 			set_opt (sbi->s_mount_opt, EXTENTS);
1115 			break;
1116 		default:
1117 			printk (KERN_ERR
1118 				"EXT4-fs: Unrecognized mount option \"%s\" "
1119 				"or missing value\n", p);
1120 			return 0;
1121 		}
1122 	}
1123 #ifdef CONFIG_QUOTA
1124 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1125 		if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1126 		     sbi->s_qf_names[USRQUOTA])
1127 			clear_opt(sbi->s_mount_opt, USRQUOTA);
1128 
1129 		if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1130 		     sbi->s_qf_names[GRPQUOTA])
1131 			clear_opt(sbi->s_mount_opt, GRPQUOTA);
1132 
1133 		if ((sbi->s_qf_names[USRQUOTA] &&
1134 				(sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1135 		    (sbi->s_qf_names[GRPQUOTA] &&
1136 				(sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1137 			printk(KERN_ERR "EXT4-fs: old and new quota "
1138 					"format mixing.\n");
1139 			return 0;
1140 		}
1141 
1142 		if (!sbi->s_jquota_fmt) {
1143 			printk(KERN_ERR "EXT4-fs: journalled quota format "
1144 					"not specified.\n");
1145 			return 0;
1146 		}
1147 	} else {
1148 		if (sbi->s_jquota_fmt) {
1149 			printk(KERN_ERR "EXT4-fs: journalled quota format "
1150 					"specified with no journalling "
1151 					"enabled.\n");
1152 			return 0;
1153 		}
1154 	}
1155 #endif
1156 	return 1;
1157 }
1158 
1159 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1160 			    int read_only)
1161 {
1162 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1163 	int res = 0;
1164 
1165 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1166 		printk (KERN_ERR "EXT4-fs warning: revision level too high, "
1167 			"forcing read-only mode\n");
1168 		res = MS_RDONLY;
1169 	}
1170 	if (read_only)
1171 		return res;
1172 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1173 		printk (KERN_WARNING "EXT4-fs warning: mounting unchecked fs, "
1174 			"running e2fsck is recommended\n");
1175 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1176 		printk (KERN_WARNING
1177 			"EXT4-fs warning: mounting fs with errors, "
1178 			"running e2fsck is recommended\n");
1179 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1180 		 le16_to_cpu(es->s_mnt_count) >=
1181 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1182 		printk (KERN_WARNING
1183 			"EXT4-fs warning: maximal mount count reached, "
1184 			"running e2fsck is recommended\n");
1185 	else if (le32_to_cpu(es->s_checkinterval) &&
1186 		(le32_to_cpu(es->s_lastcheck) +
1187 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1188 		printk (KERN_WARNING
1189 			"EXT4-fs warning: checktime reached, "
1190 			"running e2fsck is recommended\n");
1191 #if 0
1192 		/* @@@ We _will_ want to clear the valid bit if we find
1193 		 * inconsistencies, to force a fsck at reboot.  But for
1194 		 * a plain journaled filesystem we can keep it set as
1195 		 * valid forever! :)
1196 		 */
1197 	es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) & ~EXT4_VALID_FS);
1198 #endif
1199 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1200 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1201 	es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
1202 	es->s_mtime = cpu_to_le32(get_seconds());
1203 	ext4_update_dynamic_rev(sb);
1204 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1205 
1206 	ext4_commit_super(sb, es, 1);
1207 	if (test_opt(sb, DEBUG))
1208 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%lu, "
1209 				"bpg=%lu, ipg=%lu, mo=%04lx]\n",
1210 			sb->s_blocksize,
1211 			sbi->s_groups_count,
1212 			EXT4_BLOCKS_PER_GROUP(sb),
1213 			EXT4_INODES_PER_GROUP(sb),
1214 			sbi->s_mount_opt);
1215 
1216 	printk(KERN_INFO "EXT4 FS on %s, ", sb->s_id);
1217 	if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
1218 		char b[BDEVNAME_SIZE];
1219 
1220 		printk("external journal on %s\n",
1221 			bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
1222 	} else {
1223 		printk("internal journal\n");
1224 	}
1225 	return res;
1226 }
1227 
1228 /* Called at mount-time, super-block is locked */
1229 static int ext4_check_descriptors (struct super_block * sb)
1230 {
1231 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1232 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1233 	ext4_fsblk_t last_block;
1234 	ext4_fsblk_t block_bitmap;
1235 	ext4_fsblk_t inode_bitmap;
1236 	ext4_fsblk_t inode_table;
1237 	struct ext4_group_desc * gdp = NULL;
1238 	int desc_block = 0;
1239 	int i;
1240 
1241 	ext4_debug ("Checking group descriptors");
1242 
1243 	for (i = 0; i < sbi->s_groups_count; i++)
1244 	{
1245 		if (i == sbi->s_groups_count - 1)
1246 			last_block = ext4_blocks_count(sbi->s_es) - 1;
1247 		else
1248 			last_block = first_block +
1249 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
1250 
1251 		if ((i % EXT4_DESC_PER_BLOCK(sb)) == 0)
1252 			gdp = (struct ext4_group_desc *)
1253 					sbi->s_group_desc[desc_block++]->b_data;
1254 		block_bitmap = ext4_block_bitmap(sb, gdp);
1255 		if (block_bitmap < first_block || block_bitmap > last_block)
1256 		{
1257 			ext4_error (sb, "ext4_check_descriptors",
1258 				    "Block bitmap for group %d"
1259 				    " not in group (block %llu)!",
1260 				    i, block_bitmap);
1261 			return 0;
1262 		}
1263 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
1264 		if (inode_bitmap < first_block || inode_bitmap > last_block)
1265 		{
1266 			ext4_error (sb, "ext4_check_descriptors",
1267 				    "Inode bitmap for group %d"
1268 				    " not in group (block %llu)!",
1269 				    i, inode_bitmap);
1270 			return 0;
1271 		}
1272 		inode_table = ext4_inode_table(sb, gdp);
1273 		if (inode_table < first_block ||
1274 		    inode_table + sbi->s_itb_per_group > last_block)
1275 		{
1276 			ext4_error (sb, "ext4_check_descriptors",
1277 				    "Inode table for group %d"
1278 				    " not in group (block %llu)!",
1279 				    i, inode_table);
1280 			return 0;
1281 		}
1282 		first_block += EXT4_BLOCKS_PER_GROUP(sb);
1283 		gdp = (struct ext4_group_desc *)
1284 			((__u8 *)gdp + EXT4_DESC_SIZE(sb));
1285 	}
1286 
1287 	ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1288 	sbi->s_es->s_free_inodes_count=cpu_to_le32(ext4_count_free_inodes(sb));
1289 	return 1;
1290 }
1291 
1292 
1293 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1294  * the superblock) which were deleted from all directories, but held open by
1295  * a process at the time of a crash.  We walk the list and try to delete these
1296  * inodes at recovery time (only with a read-write filesystem).
1297  *
1298  * In order to keep the orphan inode chain consistent during traversal (in
1299  * case of crash during recovery), we link each inode into the superblock
1300  * orphan list_head and handle it the same way as an inode deletion during
1301  * normal operation (which journals the operations for us).
1302  *
1303  * We only do an iget() and an iput() on each inode, which is very safe if we
1304  * accidentally point at an in-use or already deleted inode.  The worst that
1305  * can happen in this case is that we get a "bit already cleared" message from
1306  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1307  * e2fsck was run on this filesystem, and it must have already done the orphan
1308  * inode cleanup for us, so we can safely abort without any further action.
1309  */
1310 static void ext4_orphan_cleanup (struct super_block * sb,
1311 				 struct ext4_super_block * es)
1312 {
1313 	unsigned int s_flags = sb->s_flags;
1314 	int nr_orphans = 0, nr_truncates = 0;
1315 #ifdef CONFIG_QUOTA
1316 	int i;
1317 #endif
1318 	if (!es->s_last_orphan) {
1319 		jbd_debug(4, "no orphan inodes to clean up\n");
1320 		return;
1321 	}
1322 
1323 	if (bdev_read_only(sb->s_bdev)) {
1324 		printk(KERN_ERR "EXT4-fs: write access "
1325 			"unavailable, skipping orphan cleanup.\n");
1326 		return;
1327 	}
1328 
1329 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1330 		if (es->s_last_orphan)
1331 			jbd_debug(1, "Errors on filesystem, "
1332 				  "clearing orphan list.\n");
1333 		es->s_last_orphan = 0;
1334 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1335 		return;
1336 	}
1337 
1338 	if (s_flags & MS_RDONLY) {
1339 		printk(KERN_INFO "EXT4-fs: %s: orphan cleanup on readonly fs\n",
1340 		       sb->s_id);
1341 		sb->s_flags &= ~MS_RDONLY;
1342 	}
1343 #ifdef CONFIG_QUOTA
1344 	/* Needed for iput() to work correctly and not trash data */
1345 	sb->s_flags |= MS_ACTIVE;
1346 	/* Turn on quotas so that they are updated correctly */
1347 	for (i = 0; i < MAXQUOTAS; i++) {
1348 		if (EXT4_SB(sb)->s_qf_names[i]) {
1349 			int ret = ext4_quota_on_mount(sb, i);
1350 			if (ret < 0)
1351 				printk(KERN_ERR
1352 					"EXT4-fs: Cannot turn on journalled "
1353 					"quota: error %d\n", ret);
1354 		}
1355 	}
1356 #endif
1357 
1358 	while (es->s_last_orphan) {
1359 		struct inode *inode;
1360 
1361 		if (!(inode =
1362 		      ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan)))) {
1363 			es->s_last_orphan = 0;
1364 			break;
1365 		}
1366 
1367 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1368 		DQUOT_INIT(inode);
1369 		if (inode->i_nlink) {
1370 			printk(KERN_DEBUG
1371 				"%s: truncating inode %lu to %Ld bytes\n",
1372 				__FUNCTION__, inode->i_ino, inode->i_size);
1373 			jbd_debug(2, "truncating inode %lu to %Ld bytes\n",
1374 				  inode->i_ino, inode->i_size);
1375 			ext4_truncate(inode);
1376 			nr_truncates++;
1377 		} else {
1378 			printk(KERN_DEBUG
1379 				"%s: deleting unreferenced inode %lu\n",
1380 				__FUNCTION__, inode->i_ino);
1381 			jbd_debug(2, "deleting unreferenced inode %lu\n",
1382 				  inode->i_ino);
1383 			nr_orphans++;
1384 		}
1385 		iput(inode);  /* The delete magic happens here! */
1386 	}
1387 
1388 #define PLURAL(x) (x), ((x)==1) ? "" : "s"
1389 
1390 	if (nr_orphans)
1391 		printk(KERN_INFO "EXT4-fs: %s: %d orphan inode%s deleted\n",
1392 		       sb->s_id, PLURAL(nr_orphans));
1393 	if (nr_truncates)
1394 		printk(KERN_INFO "EXT4-fs: %s: %d truncate%s cleaned up\n",
1395 		       sb->s_id, PLURAL(nr_truncates));
1396 #ifdef CONFIG_QUOTA
1397 	/* Turn quotas off */
1398 	for (i = 0; i < MAXQUOTAS; i++) {
1399 		if (sb_dqopt(sb)->files[i])
1400 			vfs_quota_off(sb, i);
1401 	}
1402 #endif
1403 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1404 }
1405 
1406 #define log2(n) ffz(~(n))
1407 
1408 /*
1409  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
1410  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
1411  * We need to be 1 filesystem block less than the 2^32 sector limit.
1412  */
1413 static loff_t ext4_max_size(int bits)
1414 {
1415 	loff_t res = EXT4_NDIR_BLOCKS;
1416 	/* This constant is calculated to be the largest file size for a
1417 	 * dense, 4k-blocksize file such that the total number of
1418 	 * sectors in the file, including data and all indirect blocks,
1419 	 * does not exceed 2^32. */
1420 	const loff_t upper_limit = 0x1ff7fffd000LL;
1421 
1422 	res += 1LL << (bits-2);
1423 	res += 1LL << (2*(bits-2));
1424 	res += 1LL << (3*(bits-2));
1425 	res <<= bits;
1426 	if (res > upper_limit)
1427 		res = upper_limit;
1428 	return res;
1429 }
1430 
1431 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
1432 				ext4_fsblk_t logical_sb_block, int nr)
1433 {
1434 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1435 	unsigned long bg, first_meta_bg;
1436 	int has_super = 0;
1437 
1438 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
1439 
1440 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
1441 	    nr < first_meta_bg)
1442 		return logical_sb_block + nr + 1;
1443 	bg = sbi->s_desc_per_block * nr;
1444 	if (ext4_bg_has_super(sb, bg))
1445 		has_super = 1;
1446 	return (has_super + ext4_group_first_block_no(sb, bg));
1447 }
1448 
1449 
1450 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
1451 {
1452 	struct buffer_head * bh;
1453 	struct ext4_super_block *es = NULL;
1454 	struct ext4_sb_info *sbi;
1455 	ext4_fsblk_t block;
1456 	ext4_fsblk_t sb_block = get_sb_block(&data);
1457 	ext4_fsblk_t logical_sb_block;
1458 	unsigned long offset = 0;
1459 	unsigned int journal_inum = 0;
1460 	unsigned long journal_devnum = 0;
1461 	unsigned long def_mount_opts;
1462 	struct inode *root;
1463 	int blocksize;
1464 	int hblock;
1465 	int db_count;
1466 	int i;
1467 	int needs_recovery;
1468 	__le32 features;
1469 	__u64 blocks_count;
1470 
1471 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1472 	if (!sbi)
1473 		return -ENOMEM;
1474 	sb->s_fs_info = sbi;
1475 	sbi->s_mount_opt = 0;
1476 	sbi->s_resuid = EXT4_DEF_RESUID;
1477 	sbi->s_resgid = EXT4_DEF_RESGID;
1478 
1479 	unlock_kernel();
1480 
1481 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
1482 	if (!blocksize) {
1483 		printk(KERN_ERR "EXT4-fs: unable to set blocksize\n");
1484 		goto out_fail;
1485 	}
1486 
1487 	/*
1488 	 * The ext4 superblock will not be buffer aligned for other than 1kB
1489 	 * block sizes.  We need to calculate the offset from buffer start.
1490 	 */
1491 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
1492 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1493 		offset = do_div(logical_sb_block, blocksize);
1494 	} else {
1495 		logical_sb_block = sb_block;
1496 	}
1497 
1498 	if (!(bh = sb_bread(sb, logical_sb_block))) {
1499 		printk (KERN_ERR "EXT4-fs: unable to read superblock\n");
1500 		goto out_fail;
1501 	}
1502 	/*
1503 	 * Note: s_es must be initialized as soon as possible because
1504 	 *       some ext4 macro-instructions depend on its value
1505 	 */
1506 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
1507 	sbi->s_es = es;
1508 	sb->s_magic = le16_to_cpu(es->s_magic);
1509 	if (sb->s_magic != EXT4_SUPER_MAGIC)
1510 		goto cantfind_ext4;
1511 
1512 	/* Set defaults before we parse the mount options */
1513 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1514 	if (def_mount_opts & EXT4_DEFM_DEBUG)
1515 		set_opt(sbi->s_mount_opt, DEBUG);
1516 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
1517 		set_opt(sbi->s_mount_opt, GRPID);
1518 	if (def_mount_opts & EXT4_DEFM_UID16)
1519 		set_opt(sbi->s_mount_opt, NO_UID32);
1520 #ifdef CONFIG_EXT4DEV_FS_XATTR
1521 	if (def_mount_opts & EXT4_DEFM_XATTR_USER)
1522 		set_opt(sbi->s_mount_opt, XATTR_USER);
1523 #endif
1524 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
1525 	if (def_mount_opts & EXT4_DEFM_ACL)
1526 		set_opt(sbi->s_mount_opt, POSIX_ACL);
1527 #endif
1528 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
1529 		sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
1530 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
1531 		sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
1532 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
1533 		sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
1534 
1535 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
1536 		set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1537 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_RO)
1538 		set_opt(sbi->s_mount_opt, ERRORS_RO);
1539 	else
1540 		set_opt(sbi->s_mount_opt, ERRORS_CONT);
1541 
1542 	sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
1543 	sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
1544 
1545 	set_opt(sbi->s_mount_opt, RESERVATION);
1546 
1547 	if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
1548 			    NULL, 0))
1549 		goto failed_mount;
1550 
1551 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1552 		((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1553 
1554 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
1555 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
1556 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
1557 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
1558 		printk(KERN_WARNING
1559 		       "EXT4-fs warning: feature flags set on rev 0 fs, "
1560 		       "running e2fsck is recommended\n");
1561 	/*
1562 	 * Check feature flags regardless of the revision level, since we
1563 	 * previously didn't change the revision level when setting the flags,
1564 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
1565 	 */
1566 	features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
1567 	if (features) {
1568 		printk(KERN_ERR "EXT4-fs: %s: couldn't mount because of "
1569 		       "unsupported optional features (%x).\n",
1570 		       sb->s_id, le32_to_cpu(features));
1571 		goto failed_mount;
1572 	}
1573 	features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
1574 	if (!(sb->s_flags & MS_RDONLY) && features) {
1575 		printk(KERN_ERR "EXT4-fs: %s: couldn't mount RDWR because of "
1576 		       "unsupported optional features (%x).\n",
1577 		       sb->s_id, le32_to_cpu(features));
1578 		goto failed_mount;
1579 	}
1580 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
1581 
1582 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
1583 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
1584 		printk(KERN_ERR
1585 		       "EXT4-fs: Unsupported filesystem blocksize %d on %s.\n",
1586 		       blocksize, sb->s_id);
1587 		goto failed_mount;
1588 	}
1589 
1590 	hblock = bdev_hardsect_size(sb->s_bdev);
1591 	if (sb->s_blocksize != blocksize) {
1592 		/*
1593 		 * Make sure the blocksize for the filesystem is larger
1594 		 * than the hardware sectorsize for the machine.
1595 		 */
1596 		if (blocksize < hblock) {
1597 			printk(KERN_ERR "EXT4-fs: blocksize %d too small for "
1598 			       "device blocksize %d.\n", blocksize, hblock);
1599 			goto failed_mount;
1600 		}
1601 
1602 		brelse (bh);
1603 		sb_set_blocksize(sb, blocksize);
1604 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
1605 		offset = do_div(logical_sb_block, blocksize);
1606 		bh = sb_bread(sb, logical_sb_block);
1607 		if (!bh) {
1608 			printk(KERN_ERR
1609 			       "EXT4-fs: Can't read superblock on 2nd try.\n");
1610 			goto failed_mount;
1611 		}
1612 		es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
1613 		sbi->s_es = es;
1614 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
1615 			printk (KERN_ERR
1616 				"EXT4-fs: Magic mismatch, very weird !\n");
1617 			goto failed_mount;
1618 		}
1619 	}
1620 
1621 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
1622 
1623 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
1624 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
1625 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
1626 	} else {
1627 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1628 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1629 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
1630 		    (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
1631 		    (sbi->s_inode_size > blocksize)) {
1632 			printk (KERN_ERR
1633 				"EXT4-fs: unsupported inode size: %d\n",
1634 				sbi->s_inode_size);
1635 			goto failed_mount;
1636 		}
1637 	}
1638 	sbi->s_frag_size = EXT4_MIN_FRAG_SIZE <<
1639 				   le32_to_cpu(es->s_log_frag_size);
1640 	if (blocksize != sbi->s_frag_size) {
1641 		printk(KERN_ERR
1642 		       "EXT4-fs: fragsize %lu != blocksize %u (unsupported)\n",
1643 		       sbi->s_frag_size, blocksize);
1644 		goto failed_mount;
1645 	}
1646 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
1647 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
1648 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
1649 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
1650 		    sbi->s_desc_size & (sbi->s_desc_size - 1)) {
1651 			printk(KERN_ERR
1652 			       "EXT4-fs: unsupported descriptor size %lu\n",
1653 			       sbi->s_desc_size);
1654 			goto failed_mount;
1655 		}
1656 	} else
1657 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
1658 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1659 	sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1660 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1661 	if (EXT4_INODE_SIZE(sb) == 0)
1662 		goto cantfind_ext4;
1663 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
1664 	if (sbi->s_inodes_per_block == 0)
1665 		goto cantfind_ext4;
1666 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
1667 					sbi->s_inodes_per_block;
1668 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
1669 	sbi->s_sbh = bh;
1670 	sbi->s_mount_state = le16_to_cpu(es->s_state);
1671 	sbi->s_addr_per_block_bits = log2(EXT4_ADDR_PER_BLOCK(sb));
1672 	sbi->s_desc_per_block_bits = log2(EXT4_DESC_PER_BLOCK(sb));
1673 	for (i=0; i < 4; i++)
1674 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
1675 	sbi->s_def_hash_version = es->s_def_hash_version;
1676 
1677 	if (sbi->s_blocks_per_group > blocksize * 8) {
1678 		printk (KERN_ERR
1679 			"EXT4-fs: #blocks per group too big: %lu\n",
1680 			sbi->s_blocks_per_group);
1681 		goto failed_mount;
1682 	}
1683 	if (sbi->s_frags_per_group > blocksize * 8) {
1684 		printk (KERN_ERR
1685 			"EXT4-fs: #fragments per group too big: %lu\n",
1686 			sbi->s_frags_per_group);
1687 		goto failed_mount;
1688 	}
1689 	if (sbi->s_inodes_per_group > blocksize * 8) {
1690 		printk (KERN_ERR
1691 			"EXT4-fs: #inodes per group too big: %lu\n",
1692 			sbi->s_inodes_per_group);
1693 		goto failed_mount;
1694 	}
1695 
1696 	if (ext4_blocks_count(es) >
1697 		    (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
1698 		printk(KERN_ERR "EXT4-fs: filesystem on %s:"
1699 			" too large to mount safely\n", sb->s_id);
1700 		if (sizeof(sector_t) < 8)
1701 			printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
1702 					"enabled\n");
1703 		goto failed_mount;
1704 	}
1705 
1706 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
1707 		goto cantfind_ext4;
1708 	blocks_count = (ext4_blocks_count(es) -
1709 			le32_to_cpu(es->s_first_data_block) +
1710 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
1711 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
1712 	sbi->s_groups_count = blocks_count;
1713 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
1714 		   EXT4_DESC_PER_BLOCK(sb);
1715 	sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),
1716 				    GFP_KERNEL);
1717 	if (sbi->s_group_desc == NULL) {
1718 		printk (KERN_ERR "EXT4-fs: not enough memory\n");
1719 		goto failed_mount;
1720 	}
1721 
1722 	bgl_lock_init(&sbi->s_blockgroup_lock);
1723 
1724 	for (i = 0; i < db_count; i++) {
1725 		block = descriptor_loc(sb, logical_sb_block, i);
1726 		sbi->s_group_desc[i] = sb_bread(sb, block);
1727 		if (!sbi->s_group_desc[i]) {
1728 			printk (KERN_ERR "EXT4-fs: "
1729 				"can't read group descriptor %d\n", i);
1730 			db_count = i;
1731 			goto failed_mount2;
1732 		}
1733 	}
1734 	if (!ext4_check_descriptors (sb)) {
1735 		printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
1736 		goto failed_mount2;
1737 	}
1738 	sbi->s_gdb_count = db_count;
1739 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1740 	spin_lock_init(&sbi->s_next_gen_lock);
1741 
1742 	percpu_counter_init(&sbi->s_freeblocks_counter,
1743 		ext4_count_free_blocks(sb));
1744 	percpu_counter_init(&sbi->s_freeinodes_counter,
1745 		ext4_count_free_inodes(sb));
1746 	percpu_counter_init(&sbi->s_dirs_counter,
1747 		ext4_count_dirs(sb));
1748 
1749 	/* per fileystem reservation list head & lock */
1750 	spin_lock_init(&sbi->s_rsv_window_lock);
1751 	sbi->s_rsv_window_root = RB_ROOT;
1752 	/* Add a single, static dummy reservation to the start of the
1753 	 * reservation window list --- it gives us a placeholder for
1754 	 * append-at-start-of-list which makes the allocation logic
1755 	 * _much_ simpler. */
1756 	sbi->s_rsv_window_head.rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1757 	sbi->s_rsv_window_head.rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED;
1758 	sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1759 	sbi->s_rsv_window_head.rsv_goal_size = 0;
1760 	ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
1761 
1762 	/*
1763 	 * set up enough so that it can read an inode
1764 	 */
1765 	sb->s_op = &ext4_sops;
1766 	sb->s_export_op = &ext4_export_ops;
1767 	sb->s_xattr = ext4_xattr_handlers;
1768 #ifdef CONFIG_QUOTA
1769 	sb->s_qcop = &ext4_qctl_operations;
1770 	sb->dq_op = &ext4_quota_operations;
1771 #endif
1772 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
1773 
1774 	sb->s_root = NULL;
1775 
1776 	needs_recovery = (es->s_last_orphan != 0 ||
1777 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
1778 				    EXT4_FEATURE_INCOMPAT_RECOVER));
1779 
1780 	/*
1781 	 * The first inode we look at is the journal inode.  Don't try
1782 	 * root first: it may be modified in the journal!
1783 	 */
1784 	if (!test_opt(sb, NOLOAD) &&
1785 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
1786 		if (ext4_load_journal(sb, es, journal_devnum))
1787 			goto failed_mount3;
1788 	} else if (journal_inum) {
1789 		if (ext4_create_journal(sb, es, journal_inum))
1790 			goto failed_mount3;
1791 	} else {
1792 		if (!silent)
1793 			printk (KERN_ERR
1794 				"ext4: No journal on filesystem on %s\n",
1795 				sb->s_id);
1796 		goto failed_mount3;
1797 	}
1798 
1799 	/* We have now updated the journal if required, so we can
1800 	 * validate the data journaling mode. */
1801 	switch (test_opt(sb, DATA_FLAGS)) {
1802 	case 0:
1803 		/* No mode set, assume a default based on the journal
1804 		 * capabilities: ORDERED_DATA if the journal can
1805 		 * cope, else JOURNAL_DATA
1806 		 */
1807 		if (jbd2_journal_check_available_features
1808 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
1809 			set_opt(sbi->s_mount_opt, ORDERED_DATA);
1810 		else
1811 			set_opt(sbi->s_mount_opt, JOURNAL_DATA);
1812 		break;
1813 
1814 	case EXT4_MOUNT_ORDERED_DATA:
1815 	case EXT4_MOUNT_WRITEBACK_DATA:
1816 		if (!jbd2_journal_check_available_features
1817 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
1818 			printk(KERN_ERR "EXT4-fs: Journal does not support "
1819 			       "requested data journaling mode\n");
1820 			goto failed_mount4;
1821 		}
1822 	default:
1823 		break;
1824 	}
1825 
1826 	if (test_opt(sb, NOBH)) {
1827 		if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
1828 			printk(KERN_WARNING "EXT4-fs: Ignoring nobh option - "
1829 				"its supported only with writeback mode\n");
1830 			clear_opt(sbi->s_mount_opt, NOBH);
1831 		}
1832 	}
1833 	/*
1834 	 * The jbd2_journal_load will have done any necessary log recovery,
1835 	 * so we can safely mount the rest of the filesystem now.
1836 	 */
1837 
1838 	root = iget(sb, EXT4_ROOT_INO);
1839 	sb->s_root = d_alloc_root(root);
1840 	if (!sb->s_root) {
1841 		printk(KERN_ERR "EXT4-fs: get root inode failed\n");
1842 		iput(root);
1843 		goto failed_mount4;
1844 	}
1845 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1846 		dput(sb->s_root);
1847 		sb->s_root = NULL;
1848 		printk(KERN_ERR "EXT4-fs: corrupt root inode, run e2fsck\n");
1849 		goto failed_mount4;
1850 	}
1851 
1852 	ext4_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1853 	/*
1854 	 * akpm: core read_super() calls in here with the superblock locked.
1855 	 * That deadlocks, because orphan cleanup needs to lock the superblock
1856 	 * in numerous places.  Here we just pop the lock - it's relatively
1857 	 * harmless, because we are now ready to accept write_super() requests,
1858 	 * and aviro says that's the only reason for hanging onto the
1859 	 * superblock lock.
1860 	 */
1861 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
1862 	ext4_orphan_cleanup(sb, es);
1863 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
1864 	if (needs_recovery)
1865 		printk (KERN_INFO "EXT4-fs: recovery complete.\n");
1866 	ext4_mark_recovery_complete(sb, es);
1867 	printk (KERN_INFO "EXT4-fs: mounted filesystem with %s data mode.\n",
1868 		test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ? "journal":
1869 		test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
1870 		"writeback");
1871 
1872 	ext4_ext_init(sb);
1873 
1874 	lock_kernel();
1875 	return 0;
1876 
1877 cantfind_ext4:
1878 	if (!silent)
1879 		printk(KERN_ERR "VFS: Can't find ext4 filesystem on dev %s.\n",
1880 		       sb->s_id);
1881 	goto failed_mount;
1882 
1883 failed_mount4:
1884 	jbd2_journal_destroy(sbi->s_journal);
1885 failed_mount3:
1886 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
1887 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1888 	percpu_counter_destroy(&sbi->s_dirs_counter);
1889 failed_mount2:
1890 	for (i = 0; i < db_count; i++)
1891 		brelse(sbi->s_group_desc[i]);
1892 	kfree(sbi->s_group_desc);
1893 failed_mount:
1894 #ifdef CONFIG_QUOTA
1895 	for (i = 0; i < MAXQUOTAS; i++)
1896 		kfree(sbi->s_qf_names[i]);
1897 #endif
1898 	ext4_blkdev_remove(sbi);
1899 	brelse(bh);
1900 out_fail:
1901 	sb->s_fs_info = NULL;
1902 	kfree(sbi);
1903 	lock_kernel();
1904 	return -EINVAL;
1905 }
1906 
1907 /*
1908  * Setup any per-fs journal parameters now.  We'll do this both on
1909  * initial mount, once the journal has been initialised but before we've
1910  * done any recovery; and again on any subsequent remount.
1911  */
1912 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
1913 {
1914 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1915 
1916 	if (sbi->s_commit_interval)
1917 		journal->j_commit_interval = sbi->s_commit_interval;
1918 	/* We could also set up an ext4-specific default for the commit
1919 	 * interval here, but for now we'll just fall back to the jbd
1920 	 * default. */
1921 
1922 	spin_lock(&journal->j_state_lock);
1923 	if (test_opt(sb, BARRIER))
1924 		journal->j_flags |= JBD2_BARRIER;
1925 	else
1926 		journal->j_flags &= ~JBD2_BARRIER;
1927 	spin_unlock(&journal->j_state_lock);
1928 }
1929 
1930 static journal_t *ext4_get_journal(struct super_block *sb,
1931 				   unsigned int journal_inum)
1932 {
1933 	struct inode *journal_inode;
1934 	journal_t *journal;
1935 
1936 	/* First, test for the existence of a valid inode on disk.  Bad
1937 	 * things happen if we iget() an unused inode, as the subsequent
1938 	 * iput() will try to delete it. */
1939 
1940 	journal_inode = iget(sb, journal_inum);
1941 	if (!journal_inode) {
1942 		printk(KERN_ERR "EXT4-fs: no journal found.\n");
1943 		return NULL;
1944 	}
1945 	if (!journal_inode->i_nlink) {
1946 		make_bad_inode(journal_inode);
1947 		iput(journal_inode);
1948 		printk(KERN_ERR "EXT4-fs: journal inode is deleted.\n");
1949 		return NULL;
1950 	}
1951 
1952 	jbd_debug(2, "Journal inode found at %p: %Ld bytes\n",
1953 		  journal_inode, journal_inode->i_size);
1954 	if (is_bad_inode(journal_inode) || !S_ISREG(journal_inode->i_mode)) {
1955 		printk(KERN_ERR "EXT4-fs: invalid journal inode.\n");
1956 		iput(journal_inode);
1957 		return NULL;
1958 	}
1959 
1960 	journal = jbd2_journal_init_inode(journal_inode);
1961 	if (!journal) {
1962 		printk(KERN_ERR "EXT4-fs: Could not load journal inode\n");
1963 		iput(journal_inode);
1964 		return NULL;
1965 	}
1966 	journal->j_private = sb;
1967 	ext4_init_journal_params(sb, journal);
1968 	return journal;
1969 }
1970 
1971 static journal_t *ext4_get_dev_journal(struct super_block *sb,
1972 				       dev_t j_dev)
1973 {
1974 	struct buffer_head * bh;
1975 	journal_t *journal;
1976 	ext4_fsblk_t start;
1977 	ext4_fsblk_t len;
1978 	int hblock, blocksize;
1979 	ext4_fsblk_t sb_block;
1980 	unsigned long offset;
1981 	struct ext4_super_block * es;
1982 	struct block_device *bdev;
1983 
1984 	bdev = ext4_blkdev_get(j_dev);
1985 	if (bdev == NULL)
1986 		return NULL;
1987 
1988 	if (bd_claim(bdev, sb)) {
1989 		printk(KERN_ERR
1990 		        "EXT4: failed to claim external journal device.\n");
1991 		blkdev_put(bdev);
1992 		return NULL;
1993 	}
1994 
1995 	blocksize = sb->s_blocksize;
1996 	hblock = bdev_hardsect_size(bdev);
1997 	if (blocksize < hblock) {
1998 		printk(KERN_ERR
1999 			"EXT4-fs: blocksize too small for journal device.\n");
2000 		goto out_bdev;
2001 	}
2002 
2003 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
2004 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
2005 	set_blocksize(bdev, blocksize);
2006 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
2007 		printk(KERN_ERR "EXT4-fs: couldn't read superblock of "
2008 		       "external journal\n");
2009 		goto out_bdev;
2010 	}
2011 
2012 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2013 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
2014 	    !(le32_to_cpu(es->s_feature_incompat) &
2015 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
2016 		printk(KERN_ERR "EXT4-fs: external journal has "
2017 					"bad superblock\n");
2018 		brelse(bh);
2019 		goto out_bdev;
2020 	}
2021 
2022 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
2023 		printk(KERN_ERR "EXT4-fs: journal UUID does not match\n");
2024 		brelse(bh);
2025 		goto out_bdev;
2026 	}
2027 
2028 	len = ext4_blocks_count(es);
2029 	start = sb_block + 1;
2030 	brelse(bh);	/* we're done with the superblock */
2031 
2032 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
2033 					start, len, blocksize);
2034 	if (!journal) {
2035 		printk(KERN_ERR "EXT4-fs: failed to create device journal\n");
2036 		goto out_bdev;
2037 	}
2038 	journal->j_private = sb;
2039 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
2040 	wait_on_buffer(journal->j_sb_buffer);
2041 	if (!buffer_uptodate(journal->j_sb_buffer)) {
2042 		printk(KERN_ERR "EXT4-fs: I/O error on journal device\n");
2043 		goto out_journal;
2044 	}
2045 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
2046 		printk(KERN_ERR "EXT4-fs: External journal has more than one "
2047 					"user (unsupported) - %d\n",
2048 			be32_to_cpu(journal->j_superblock->s_nr_users));
2049 		goto out_journal;
2050 	}
2051 	EXT4_SB(sb)->journal_bdev = bdev;
2052 	ext4_init_journal_params(sb, journal);
2053 	return journal;
2054 out_journal:
2055 	jbd2_journal_destroy(journal);
2056 out_bdev:
2057 	ext4_blkdev_put(bdev);
2058 	return NULL;
2059 }
2060 
2061 static int ext4_load_journal(struct super_block *sb,
2062 			     struct ext4_super_block *es,
2063 			     unsigned long journal_devnum)
2064 {
2065 	journal_t *journal;
2066 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
2067 	dev_t journal_dev;
2068 	int err = 0;
2069 	int really_read_only;
2070 
2071 	if (journal_devnum &&
2072 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2073 		printk(KERN_INFO "EXT4-fs: external journal device major/minor "
2074 			"numbers have changed\n");
2075 		journal_dev = new_decode_dev(journal_devnum);
2076 	} else
2077 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
2078 
2079 	really_read_only = bdev_read_only(sb->s_bdev);
2080 
2081 	/*
2082 	 * Are we loading a blank journal or performing recovery after a
2083 	 * crash?  For recovery, we need to check in advance whether we
2084 	 * can get read-write access to the device.
2085 	 */
2086 
2087 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2088 		if (sb->s_flags & MS_RDONLY) {
2089 			printk(KERN_INFO "EXT4-fs: INFO: recovery "
2090 					"required on readonly filesystem.\n");
2091 			if (really_read_only) {
2092 				printk(KERN_ERR "EXT4-fs: write access "
2093 					"unavailable, cannot proceed.\n");
2094 				return -EROFS;
2095 			}
2096 			printk (KERN_INFO "EXT4-fs: write access will "
2097 					"be enabled during recovery.\n");
2098 		}
2099 	}
2100 
2101 	if (journal_inum && journal_dev) {
2102 		printk(KERN_ERR "EXT4-fs: filesystem has both journal "
2103 		       "and inode journals!\n");
2104 		return -EINVAL;
2105 	}
2106 
2107 	if (journal_inum) {
2108 		if (!(journal = ext4_get_journal(sb, journal_inum)))
2109 			return -EINVAL;
2110 	} else {
2111 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
2112 			return -EINVAL;
2113 	}
2114 
2115 	if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
2116 		err = jbd2_journal_update_format(journal);
2117 		if (err)  {
2118 			printk(KERN_ERR "EXT4-fs: error updating journal.\n");
2119 			jbd2_journal_destroy(journal);
2120 			return err;
2121 		}
2122 	}
2123 
2124 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
2125 		err = jbd2_journal_wipe(journal, !really_read_only);
2126 	if (!err)
2127 		err = jbd2_journal_load(journal);
2128 
2129 	if (err) {
2130 		printk(KERN_ERR "EXT4-fs: error loading journal.\n");
2131 		jbd2_journal_destroy(journal);
2132 		return err;
2133 	}
2134 
2135 	EXT4_SB(sb)->s_journal = journal;
2136 	ext4_clear_journal_err(sb, es);
2137 
2138 	if (journal_devnum &&
2139 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
2140 		es->s_journal_dev = cpu_to_le32(journal_devnum);
2141 		sb->s_dirt = 1;
2142 
2143 		/* Make sure we flush the recovery flag to disk. */
2144 		ext4_commit_super(sb, es, 1);
2145 	}
2146 
2147 	return 0;
2148 }
2149 
2150 static int ext4_create_journal(struct super_block * sb,
2151 			       struct ext4_super_block * es,
2152 			       unsigned int journal_inum)
2153 {
2154 	journal_t *journal;
2155 
2156 	if (sb->s_flags & MS_RDONLY) {
2157 		printk(KERN_ERR "EXT4-fs: readonly filesystem when trying to "
2158 				"create journal.\n");
2159 		return -EROFS;
2160 	}
2161 
2162 	if (!(journal = ext4_get_journal(sb, journal_inum)))
2163 		return -EINVAL;
2164 
2165 	printk(KERN_INFO "EXT4-fs: creating new journal on inode %u\n",
2166 	       journal_inum);
2167 
2168 	if (jbd2_journal_create(journal)) {
2169 		printk(KERN_ERR "EXT4-fs: error creating journal.\n");
2170 		jbd2_journal_destroy(journal);
2171 		return -EIO;
2172 	}
2173 
2174 	EXT4_SB(sb)->s_journal = journal;
2175 
2176 	ext4_update_dynamic_rev(sb);
2177 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2178 	EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL);
2179 
2180 	es->s_journal_inum = cpu_to_le32(journal_inum);
2181 	sb->s_dirt = 1;
2182 
2183 	/* Make sure we flush the recovery flag to disk. */
2184 	ext4_commit_super(sb, es, 1);
2185 
2186 	return 0;
2187 }
2188 
2189 static void ext4_commit_super (struct super_block * sb,
2190 			       struct ext4_super_block * es,
2191 			       int sync)
2192 {
2193 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
2194 
2195 	if (!sbh)
2196 		return;
2197 	es->s_wtime = cpu_to_le32(get_seconds());
2198 	ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
2199 	es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
2200 	BUFFER_TRACE(sbh, "marking dirty");
2201 	mark_buffer_dirty(sbh);
2202 	if (sync)
2203 		sync_dirty_buffer(sbh);
2204 }
2205 
2206 
2207 /*
2208  * Have we just finished recovery?  If so, and if we are mounting (or
2209  * remounting) the filesystem readonly, then we will end up with a
2210  * consistent fs on disk.  Record that fact.
2211  */
2212 static void ext4_mark_recovery_complete(struct super_block * sb,
2213 					struct ext4_super_block * es)
2214 {
2215 	journal_t *journal = EXT4_SB(sb)->s_journal;
2216 
2217 	jbd2_journal_lock_updates(journal);
2218 	jbd2_journal_flush(journal);
2219 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
2220 	    sb->s_flags & MS_RDONLY) {
2221 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2222 		sb->s_dirt = 0;
2223 		ext4_commit_super(sb, es, 1);
2224 	}
2225 	jbd2_journal_unlock_updates(journal);
2226 }
2227 
2228 /*
2229  * If we are mounting (or read-write remounting) a filesystem whose journal
2230  * has recorded an error from a previous lifetime, move that error to the
2231  * main filesystem now.
2232  */
2233 static void ext4_clear_journal_err(struct super_block * sb,
2234 				   struct ext4_super_block * es)
2235 {
2236 	journal_t *journal;
2237 	int j_errno;
2238 	const char *errstr;
2239 
2240 	journal = EXT4_SB(sb)->s_journal;
2241 
2242 	/*
2243 	 * Now check for any error status which may have been recorded in the
2244 	 * journal by a prior ext4_error() or ext4_abort()
2245 	 */
2246 
2247 	j_errno = jbd2_journal_errno(journal);
2248 	if (j_errno) {
2249 		char nbuf[16];
2250 
2251 		errstr = ext4_decode_error(sb, j_errno, nbuf);
2252 		ext4_warning(sb, __FUNCTION__, "Filesystem error recorded "
2253 			     "from previous mount: %s", errstr);
2254 		ext4_warning(sb, __FUNCTION__, "Marking fs in need of "
2255 			     "filesystem check.");
2256 
2257 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2258 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2259 		ext4_commit_super (sb, es, 1);
2260 
2261 		jbd2_journal_clear_err(journal);
2262 	}
2263 }
2264 
2265 /*
2266  * Force the running and committing transactions to commit,
2267  * and wait on the commit.
2268  */
2269 int ext4_force_commit(struct super_block *sb)
2270 {
2271 	journal_t *journal;
2272 	int ret;
2273 
2274 	if (sb->s_flags & MS_RDONLY)
2275 		return 0;
2276 
2277 	journal = EXT4_SB(sb)->s_journal;
2278 	sb->s_dirt = 0;
2279 	ret = ext4_journal_force_commit(journal);
2280 	return ret;
2281 }
2282 
2283 /*
2284  * Ext4 always journals updates to the superblock itself, so we don't
2285  * have to propagate any other updates to the superblock on disk at this
2286  * point.  Just start an async writeback to get the buffers on their way
2287  * to the disk.
2288  *
2289  * This implicitly triggers the writebehind on sync().
2290  */
2291 
2292 static void ext4_write_super (struct super_block * sb)
2293 {
2294 	if (mutex_trylock(&sb->s_lock) != 0)
2295 		BUG();
2296 	sb->s_dirt = 0;
2297 }
2298 
2299 static int ext4_sync_fs(struct super_block *sb, int wait)
2300 {
2301 	tid_t target;
2302 
2303 	sb->s_dirt = 0;
2304 	if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
2305 		if (wait)
2306 			jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
2307 	}
2308 	return 0;
2309 }
2310 
2311 /*
2312  * LVM calls this function before a (read-only) snapshot is created.  This
2313  * gives us a chance to flush the journal completely and mark the fs clean.
2314  */
2315 static void ext4_write_super_lockfs(struct super_block *sb)
2316 {
2317 	sb->s_dirt = 0;
2318 
2319 	if (!(sb->s_flags & MS_RDONLY)) {
2320 		journal_t *journal = EXT4_SB(sb)->s_journal;
2321 
2322 		/* Now we set up the journal barrier. */
2323 		jbd2_journal_lock_updates(journal);
2324 		jbd2_journal_flush(journal);
2325 
2326 		/* Journal blocked and flushed, clear needs_recovery flag. */
2327 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2328 		ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2329 	}
2330 }
2331 
2332 /*
2333  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
2334  * flag here, even though the filesystem is not technically dirty yet.
2335  */
2336 static void ext4_unlockfs(struct super_block *sb)
2337 {
2338 	if (!(sb->s_flags & MS_RDONLY)) {
2339 		lock_super(sb);
2340 		/* Reser the needs_recovery flag before the fs is unlocked. */
2341 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
2342 		ext4_commit_super(sb, EXT4_SB(sb)->s_es, 1);
2343 		unlock_super(sb);
2344 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
2345 	}
2346 }
2347 
2348 static int ext4_remount (struct super_block * sb, int * flags, char * data)
2349 {
2350 	struct ext4_super_block * es;
2351 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2352 	ext4_fsblk_t n_blocks_count = 0;
2353 	unsigned long old_sb_flags;
2354 	struct ext4_mount_options old_opts;
2355 	int err;
2356 #ifdef CONFIG_QUOTA
2357 	int i;
2358 #endif
2359 
2360 	/* Store the original options */
2361 	old_sb_flags = sb->s_flags;
2362 	old_opts.s_mount_opt = sbi->s_mount_opt;
2363 	old_opts.s_resuid = sbi->s_resuid;
2364 	old_opts.s_resgid = sbi->s_resgid;
2365 	old_opts.s_commit_interval = sbi->s_commit_interval;
2366 #ifdef CONFIG_QUOTA
2367 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
2368 	for (i = 0; i < MAXQUOTAS; i++)
2369 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
2370 #endif
2371 
2372 	/*
2373 	 * Allow the "check" option to be passed as a remount option.
2374 	 */
2375 	if (!parse_options(data, sb, NULL, NULL, &n_blocks_count, 1)) {
2376 		err = -EINVAL;
2377 		goto restore_opts;
2378 	}
2379 
2380 	if (sbi->s_mount_opt & EXT4_MOUNT_ABORT)
2381 		ext4_abort(sb, __FUNCTION__, "Abort forced by user");
2382 
2383 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2384 		((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2385 
2386 	es = sbi->s_es;
2387 
2388 	ext4_init_journal_params(sb, sbi->s_journal);
2389 
2390 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
2391 		n_blocks_count > ext4_blocks_count(es)) {
2392 		if (sbi->s_mount_opt & EXT4_MOUNT_ABORT) {
2393 			err = -EROFS;
2394 			goto restore_opts;
2395 		}
2396 
2397 		if (*flags & MS_RDONLY) {
2398 			/*
2399 			 * First of all, the unconditional stuff we have to do
2400 			 * to disable replay of the journal when we next remount
2401 			 */
2402 			sb->s_flags |= MS_RDONLY;
2403 
2404 			/*
2405 			 * OK, test if we are remounting a valid rw partition
2406 			 * readonly, and if so set the rdonly flag and then
2407 			 * mark the partition as valid again.
2408 			 */
2409 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
2410 			    (sbi->s_mount_state & EXT4_VALID_FS))
2411 				es->s_state = cpu_to_le16(sbi->s_mount_state);
2412 
2413 			ext4_mark_recovery_complete(sb, es);
2414 		} else {
2415 			__le32 ret;
2416 			if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2417 					~EXT4_FEATURE_RO_COMPAT_SUPP))) {
2418 				printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2419 				       "remount RDWR because of unsupported "
2420 				       "optional features (%x).\n",
2421 				       sb->s_id, le32_to_cpu(ret));
2422 				err = -EROFS;
2423 				goto restore_opts;
2424 			}
2425 
2426 			/*
2427 			 * If we have an unprocessed orphan list hanging
2428 			 * around from a previously readonly bdev mount,
2429 			 * require a full umount/remount for now.
2430 			 */
2431 			if (es->s_last_orphan) {
2432 				printk(KERN_WARNING "EXT4-fs: %s: couldn't "
2433 				       "remount RDWR because of unprocessed "
2434 				       "orphan inode list.  Please "
2435 				       "umount/remount instead.\n",
2436 				       sb->s_id);
2437 				err = -EINVAL;
2438 				goto restore_opts;
2439 			}
2440 
2441 			/*
2442 			 * Mounting a RDONLY partition read-write, so reread
2443 			 * and store the current valid flag.  (It may have
2444 			 * been changed by e2fsck since we originally mounted
2445 			 * the partition.)
2446 			 */
2447 			ext4_clear_journal_err(sb, es);
2448 			sbi->s_mount_state = le16_to_cpu(es->s_state);
2449 			if ((err = ext4_group_extend(sb, es, n_blocks_count)))
2450 				goto restore_opts;
2451 			if (!ext4_setup_super (sb, es, 0))
2452 				sb->s_flags &= ~MS_RDONLY;
2453 		}
2454 	}
2455 #ifdef CONFIG_QUOTA
2456 	/* Release old quota file names */
2457 	for (i = 0; i < MAXQUOTAS; i++)
2458 		if (old_opts.s_qf_names[i] &&
2459 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2460 			kfree(old_opts.s_qf_names[i]);
2461 #endif
2462 	return 0;
2463 restore_opts:
2464 	sb->s_flags = old_sb_flags;
2465 	sbi->s_mount_opt = old_opts.s_mount_opt;
2466 	sbi->s_resuid = old_opts.s_resuid;
2467 	sbi->s_resgid = old_opts.s_resgid;
2468 	sbi->s_commit_interval = old_opts.s_commit_interval;
2469 #ifdef CONFIG_QUOTA
2470 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
2471 	for (i = 0; i < MAXQUOTAS; i++) {
2472 		if (sbi->s_qf_names[i] &&
2473 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
2474 			kfree(sbi->s_qf_names[i]);
2475 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
2476 	}
2477 #endif
2478 	return err;
2479 }
2480 
2481 static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
2482 {
2483 	struct super_block *sb = dentry->d_sb;
2484 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2485 	struct ext4_super_block *es = sbi->s_es;
2486 	ext4_fsblk_t overhead;
2487 	int i;
2488 	u64 fsid;
2489 
2490 	if (test_opt (sb, MINIX_DF))
2491 		overhead = 0;
2492 	else {
2493 		unsigned long ngroups;
2494 		ngroups = EXT4_SB(sb)->s_groups_count;
2495 		smp_rmb();
2496 
2497 		/*
2498 		 * Compute the overhead (FS structures)
2499 		 */
2500 
2501 		/*
2502 		 * All of the blocks before first_data_block are
2503 		 * overhead
2504 		 */
2505 		overhead = le32_to_cpu(es->s_first_data_block);
2506 
2507 		/*
2508 		 * Add the overhead attributed to the superblock and
2509 		 * block group descriptors.  If the sparse superblocks
2510 		 * feature is turned on, then not all groups have this.
2511 		 */
2512 		for (i = 0; i < ngroups; i++) {
2513 			overhead += ext4_bg_has_super(sb, i) +
2514 				ext4_bg_num_gdb(sb, i);
2515 			cond_resched();
2516 		}
2517 
2518 		/*
2519 		 * Every block group has an inode bitmap, a block
2520 		 * bitmap, and an inode table.
2521 		 */
2522 		overhead += (ngroups * (2 + EXT4_SB(sb)->s_itb_per_group));
2523 	}
2524 
2525 	buf->f_type = EXT4_SUPER_MAGIC;
2526 	buf->f_bsize = sb->s_blocksize;
2527 	buf->f_blocks = ext4_blocks_count(es) - overhead;
2528 	buf->f_bfree = percpu_counter_sum(&sbi->s_freeblocks_counter);
2529 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
2530 	if (buf->f_bfree < ext4_r_blocks_count(es))
2531 		buf->f_bavail = 0;
2532 	buf->f_files = le32_to_cpu(es->s_inodes_count);
2533 	buf->f_ffree = percpu_counter_sum(&sbi->s_freeinodes_counter);
2534 	buf->f_namelen = EXT4_NAME_LEN;
2535 	fsid = le64_to_cpup((void *)es->s_uuid) ^
2536 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
2537 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
2538 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
2539 	return 0;
2540 }
2541 
2542 /* Helper function for writing quotas on sync - we need to start transaction before quota file
2543  * is locked for write. Otherwise the are possible deadlocks:
2544  * Process 1                         Process 2
2545  * ext4_create()                     quota_sync()
2546  *   jbd2_journal_start()                   write_dquot()
2547  *   DQUOT_INIT()                        down(dqio_mutex)
2548  *     down(dqio_mutex)                    jbd2_journal_start()
2549  *
2550  */
2551 
2552 #ifdef CONFIG_QUOTA
2553 
2554 static inline struct inode *dquot_to_inode(struct dquot *dquot)
2555 {
2556 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
2557 }
2558 
2559 static int ext4_dquot_initialize(struct inode *inode, int type)
2560 {
2561 	handle_t *handle;
2562 	int ret, err;
2563 
2564 	/* We may create quota structure so we need to reserve enough blocks */
2565 	handle = ext4_journal_start(inode, 2*EXT4_QUOTA_INIT_BLOCKS(inode->i_sb));
2566 	if (IS_ERR(handle))
2567 		return PTR_ERR(handle);
2568 	ret = dquot_initialize(inode, type);
2569 	err = ext4_journal_stop(handle);
2570 	if (!ret)
2571 		ret = err;
2572 	return ret;
2573 }
2574 
2575 static int ext4_dquot_drop(struct inode *inode)
2576 {
2577 	handle_t *handle;
2578 	int ret, err;
2579 
2580 	/* We may delete quota structure so we need to reserve enough blocks */
2581 	handle = ext4_journal_start(inode, 2*EXT4_QUOTA_DEL_BLOCKS(inode->i_sb));
2582 	if (IS_ERR(handle))
2583 		return PTR_ERR(handle);
2584 	ret = dquot_drop(inode);
2585 	err = ext4_journal_stop(handle);
2586 	if (!ret)
2587 		ret = err;
2588 	return ret;
2589 }
2590 
2591 static int ext4_write_dquot(struct dquot *dquot)
2592 {
2593 	int ret, err;
2594 	handle_t *handle;
2595 	struct inode *inode;
2596 
2597 	inode = dquot_to_inode(dquot);
2598 	handle = ext4_journal_start(inode,
2599 					EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
2600 	if (IS_ERR(handle))
2601 		return PTR_ERR(handle);
2602 	ret = dquot_commit(dquot);
2603 	err = ext4_journal_stop(handle);
2604 	if (!ret)
2605 		ret = err;
2606 	return ret;
2607 }
2608 
2609 static int ext4_acquire_dquot(struct dquot *dquot)
2610 {
2611 	int ret, err;
2612 	handle_t *handle;
2613 
2614 	handle = ext4_journal_start(dquot_to_inode(dquot),
2615 					EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
2616 	if (IS_ERR(handle))
2617 		return PTR_ERR(handle);
2618 	ret = dquot_acquire(dquot);
2619 	err = ext4_journal_stop(handle);
2620 	if (!ret)
2621 		ret = err;
2622 	return ret;
2623 }
2624 
2625 static int ext4_release_dquot(struct dquot *dquot)
2626 {
2627 	int ret, err;
2628 	handle_t *handle;
2629 
2630 	handle = ext4_journal_start(dquot_to_inode(dquot),
2631 					EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
2632 	if (IS_ERR(handle))
2633 		return PTR_ERR(handle);
2634 	ret = dquot_release(dquot);
2635 	err = ext4_journal_stop(handle);
2636 	if (!ret)
2637 		ret = err;
2638 	return ret;
2639 }
2640 
2641 static int ext4_mark_dquot_dirty(struct dquot *dquot)
2642 {
2643 	/* Are we journalling quotas? */
2644 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
2645 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
2646 		dquot_mark_dquot_dirty(dquot);
2647 		return ext4_write_dquot(dquot);
2648 	} else {
2649 		return dquot_mark_dquot_dirty(dquot);
2650 	}
2651 }
2652 
2653 static int ext4_write_info(struct super_block *sb, int type)
2654 {
2655 	int ret, err;
2656 	handle_t *handle;
2657 
2658 	/* Data block + inode block */
2659 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
2660 	if (IS_ERR(handle))
2661 		return PTR_ERR(handle);
2662 	ret = dquot_commit_info(sb, type);
2663 	err = ext4_journal_stop(handle);
2664 	if (!ret)
2665 		ret = err;
2666 	return ret;
2667 }
2668 
2669 /*
2670  * Turn on quotas during mount time - we need to find
2671  * the quota file and such...
2672  */
2673 static int ext4_quota_on_mount(struct super_block *sb, int type)
2674 {
2675 	return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
2676 			EXT4_SB(sb)->s_jquota_fmt, type);
2677 }
2678 
2679 /*
2680  * Standard function to be called on quota_on
2681  */
2682 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
2683 			 char *path)
2684 {
2685 	int err;
2686 	struct nameidata nd;
2687 
2688 	if (!test_opt(sb, QUOTA))
2689 		return -EINVAL;
2690 	/* Not journalling quota? */
2691 	if (!EXT4_SB(sb)->s_qf_names[USRQUOTA] &&
2692 	    !EXT4_SB(sb)->s_qf_names[GRPQUOTA])
2693 		return vfs_quota_on(sb, type, format_id, path);
2694 	err = path_lookup(path, LOOKUP_FOLLOW, &nd);
2695 	if (err)
2696 		return err;
2697 	/* Quotafile not on the same filesystem? */
2698 	if (nd.mnt->mnt_sb != sb) {
2699 		path_release(&nd);
2700 		return -EXDEV;
2701 	}
2702 	/* Quotafile not of fs root? */
2703 	if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
2704 		printk(KERN_WARNING
2705 			"EXT4-fs: Quota file not on filesystem root. "
2706 			"Journalled quota will not work.\n");
2707 	path_release(&nd);
2708 	return vfs_quota_on(sb, type, format_id, path);
2709 }
2710 
2711 /* Read data from quotafile - avoid pagecache and such because we cannot afford
2712  * acquiring the locks... As quota files are never truncated and quota code
2713  * itself serializes the operations (and noone else should touch the files)
2714  * we don't have to be afraid of races */
2715 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
2716 			       size_t len, loff_t off)
2717 {
2718 	struct inode *inode = sb_dqopt(sb)->files[type];
2719 	sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2720 	int err = 0;
2721 	int offset = off & (sb->s_blocksize - 1);
2722 	int tocopy;
2723 	size_t toread;
2724 	struct buffer_head *bh;
2725 	loff_t i_size = i_size_read(inode);
2726 
2727 	if (off > i_size)
2728 		return 0;
2729 	if (off+len > i_size)
2730 		len = i_size-off;
2731 	toread = len;
2732 	while (toread > 0) {
2733 		tocopy = sb->s_blocksize - offset < toread ?
2734 				sb->s_blocksize - offset : toread;
2735 		bh = ext4_bread(NULL, inode, blk, 0, &err);
2736 		if (err)
2737 			return err;
2738 		if (!bh)	/* A hole? */
2739 			memset(data, 0, tocopy);
2740 		else
2741 			memcpy(data, bh->b_data+offset, tocopy);
2742 		brelse(bh);
2743 		offset = 0;
2744 		toread -= tocopy;
2745 		data += tocopy;
2746 		blk++;
2747 	}
2748 	return len;
2749 }
2750 
2751 /* Write to quotafile (we know the transaction is already started and has
2752  * enough credits) */
2753 static ssize_t ext4_quota_write(struct super_block *sb, int type,
2754 				const char *data, size_t len, loff_t off)
2755 {
2756 	struct inode *inode = sb_dqopt(sb)->files[type];
2757 	sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
2758 	int err = 0;
2759 	int offset = off & (sb->s_blocksize - 1);
2760 	int tocopy;
2761 	int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
2762 	size_t towrite = len;
2763 	struct buffer_head *bh;
2764 	handle_t *handle = journal_current_handle();
2765 
2766 	mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
2767 	while (towrite > 0) {
2768 		tocopy = sb->s_blocksize - offset < towrite ?
2769 				sb->s_blocksize - offset : towrite;
2770 		bh = ext4_bread(handle, inode, blk, 1, &err);
2771 		if (!bh)
2772 			goto out;
2773 		if (journal_quota) {
2774 			err = ext4_journal_get_write_access(handle, bh);
2775 			if (err) {
2776 				brelse(bh);
2777 				goto out;
2778 			}
2779 		}
2780 		lock_buffer(bh);
2781 		memcpy(bh->b_data+offset, data, tocopy);
2782 		flush_dcache_page(bh->b_page);
2783 		unlock_buffer(bh);
2784 		if (journal_quota)
2785 			err = ext4_journal_dirty_metadata(handle, bh);
2786 		else {
2787 			/* Always do at least ordered writes for quotas */
2788 			err = ext4_journal_dirty_data(handle, bh);
2789 			mark_buffer_dirty(bh);
2790 		}
2791 		brelse(bh);
2792 		if (err)
2793 			goto out;
2794 		offset = 0;
2795 		towrite -= tocopy;
2796 		data += tocopy;
2797 		blk++;
2798 	}
2799 out:
2800 	if (len == towrite)
2801 		return err;
2802 	if (inode->i_size < off+len-towrite) {
2803 		i_size_write(inode, off+len-towrite);
2804 		EXT4_I(inode)->i_disksize = inode->i_size;
2805 	}
2806 	inode->i_version++;
2807 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2808 	ext4_mark_inode_dirty(handle, inode);
2809 	mutex_unlock(&inode->i_mutex);
2810 	return len - towrite;
2811 }
2812 
2813 #endif
2814 
2815 static int ext4_get_sb(struct file_system_type *fs_type,
2816 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
2817 {
2818 	return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
2819 }
2820 
2821 static struct file_system_type ext4dev_fs_type = {
2822 	.owner		= THIS_MODULE,
2823 	.name		= "ext4dev",
2824 	.get_sb		= ext4_get_sb,
2825 	.kill_sb	= kill_block_super,
2826 	.fs_flags	= FS_REQUIRES_DEV,
2827 };
2828 
2829 static int __init init_ext4_fs(void)
2830 {
2831 	int err = init_ext4_xattr();
2832 	if (err)
2833 		return err;
2834 	err = init_inodecache();
2835 	if (err)
2836 		goto out1;
2837 	err = register_filesystem(&ext4dev_fs_type);
2838 	if (err)
2839 		goto out;
2840 	return 0;
2841 out:
2842 	destroy_inodecache();
2843 out1:
2844 	exit_ext4_xattr();
2845 	return err;
2846 }
2847 
2848 static void __exit exit_ext4_fs(void)
2849 {
2850 	unregister_filesystem(&ext4dev_fs_type);
2851 	destroy_inodecache();
2852 	exit_ext4_xattr();
2853 }
2854 
2855 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
2856 MODULE_DESCRIPTION("Fourth Extended Filesystem with extents");
2857 MODULE_LICENSE("GPL");
2858 module_init(init_ext4_fs)
2859 module_exit(exit_ext4_fs)
2860