xref: /linux/fs/ext4/super.c (revision 5bdef865eb358b6f3760e25e591ae115e9eeddef)
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/vmalloc.h>
24 #include <linux/jbd2.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/parser.h>
29 #include <linux/smp_lock.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.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 #include <linux/proc_fs.h>
39 #include <linux/ctype.h>
40 #include <linux/log2.h>
41 #include <linux/crc16.h>
42 #include <asm/uaccess.h>
43 
44 #include "ext4.h"
45 #include "ext4_jbd2.h"
46 #include "xattr.h"
47 #include "acl.h"
48 
49 #define CREATE_TRACE_POINTS
50 #include <trace/events/ext4.h>
51 
52 static int default_mb_history_length = 1000;
53 
54 module_param_named(default_mb_history_length, default_mb_history_length,
55 		   int, 0644);
56 MODULE_PARM_DESC(default_mb_history_length,
57 		 "Default number of entries saved for mb_history");
58 
59 struct proc_dir_entry *ext4_proc_root;
60 static struct kset *ext4_kset;
61 
62 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
63 			     unsigned long journal_devnum);
64 static int ext4_commit_super(struct super_block *sb, int sync);
65 static void ext4_mark_recovery_complete(struct super_block *sb,
66 					struct ext4_super_block *es);
67 static void ext4_clear_journal_err(struct super_block *sb,
68 				   struct ext4_super_block *es);
69 static int ext4_sync_fs(struct super_block *sb, int wait);
70 static const char *ext4_decode_error(struct super_block *sb, int errno,
71 				     char nbuf[16]);
72 static int ext4_remount(struct super_block *sb, int *flags, char *data);
73 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
74 static int ext4_unfreeze(struct super_block *sb);
75 static void ext4_write_super(struct super_block *sb);
76 static int ext4_freeze(struct super_block *sb);
77 
78 
79 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
80 			       struct ext4_group_desc *bg)
81 {
82 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
83 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
84 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
85 }
86 
87 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
88 			       struct ext4_group_desc *bg)
89 {
90 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
91 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
92 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
93 }
94 
95 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
96 			      struct ext4_group_desc *bg)
97 {
98 	return le32_to_cpu(bg->bg_inode_table_lo) |
99 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
100 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
101 }
102 
103 __u32 ext4_free_blks_count(struct super_block *sb,
104 			      struct ext4_group_desc *bg)
105 {
106 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
107 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
108 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
109 }
110 
111 __u32 ext4_free_inodes_count(struct super_block *sb,
112 			      struct ext4_group_desc *bg)
113 {
114 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
115 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
116 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
117 }
118 
119 __u32 ext4_used_dirs_count(struct super_block *sb,
120 			      struct ext4_group_desc *bg)
121 {
122 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
123 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
124 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
125 }
126 
127 __u32 ext4_itable_unused_count(struct super_block *sb,
128 			      struct ext4_group_desc *bg)
129 {
130 	return le16_to_cpu(bg->bg_itable_unused_lo) |
131 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
132 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
133 }
134 
135 void ext4_block_bitmap_set(struct super_block *sb,
136 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
137 {
138 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
139 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
140 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
141 }
142 
143 void ext4_inode_bitmap_set(struct super_block *sb,
144 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
145 {
146 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
147 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
148 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
149 }
150 
151 void ext4_inode_table_set(struct super_block *sb,
152 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
153 {
154 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
155 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
156 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
157 }
158 
159 void ext4_free_blks_set(struct super_block *sb,
160 			  struct ext4_group_desc *bg, __u32 count)
161 {
162 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
163 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
164 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
165 }
166 
167 void ext4_free_inodes_set(struct super_block *sb,
168 			  struct ext4_group_desc *bg, __u32 count)
169 {
170 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
171 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
172 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
173 }
174 
175 void ext4_used_dirs_set(struct super_block *sb,
176 			  struct ext4_group_desc *bg, __u32 count)
177 {
178 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
179 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
180 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
181 }
182 
183 void ext4_itable_unused_set(struct super_block *sb,
184 			  struct ext4_group_desc *bg, __u32 count)
185 {
186 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
187 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
188 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
189 }
190 
191 /*
192  * Wrappers for jbd2_journal_start/end.
193  *
194  * The only special thing we need to do here is to make sure that all
195  * journal_end calls result in the superblock being marked dirty, so
196  * that sync() will call the filesystem's write_super callback if
197  * appropriate.
198  */
199 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
200 {
201 	journal_t *journal;
202 
203 	if (sb->s_flags & MS_RDONLY)
204 		return ERR_PTR(-EROFS);
205 
206 	/* Special case here: if the journal has aborted behind our
207 	 * backs (eg. EIO in the commit thread), then we still need to
208 	 * take the FS itself readonly cleanly. */
209 	journal = EXT4_SB(sb)->s_journal;
210 	if (journal) {
211 		if (is_journal_aborted(journal)) {
212 			ext4_abort(sb, __func__, "Detected aborted journal");
213 			return ERR_PTR(-EROFS);
214 		}
215 		return jbd2_journal_start(journal, nblocks);
216 	}
217 	/*
218 	 * We're not journaling, return the appropriate indication.
219 	 */
220 	current->journal_info = EXT4_NOJOURNAL_HANDLE;
221 	return current->journal_info;
222 }
223 
224 /*
225  * The only special thing we need to do here is to make sure that all
226  * jbd2_journal_stop calls result in the superblock being marked dirty, so
227  * that sync() will call the filesystem's write_super callback if
228  * appropriate.
229  */
230 int __ext4_journal_stop(const char *where, handle_t *handle)
231 {
232 	struct super_block *sb;
233 	int err;
234 	int rc;
235 
236 	if (!ext4_handle_valid(handle)) {
237 		/*
238 		 * Do this here since we don't call jbd2_journal_stop() in
239 		 * no-journal mode.
240 		 */
241 		current->journal_info = NULL;
242 		return 0;
243 	}
244 	sb = handle->h_transaction->t_journal->j_private;
245 	err = handle->h_err;
246 	rc = jbd2_journal_stop(handle);
247 
248 	if (!err)
249 		err = rc;
250 	if (err)
251 		__ext4_std_error(sb, where, err);
252 	return err;
253 }
254 
255 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
256 		struct buffer_head *bh, handle_t *handle, int err)
257 {
258 	char nbuf[16];
259 	const char *errstr = ext4_decode_error(NULL, err, nbuf);
260 
261 	BUG_ON(!ext4_handle_valid(handle));
262 
263 	if (bh)
264 		BUFFER_TRACE(bh, "abort");
265 
266 	if (!handle->h_err)
267 		handle->h_err = err;
268 
269 	if (is_handle_aborted(handle))
270 		return;
271 
272 	printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
273 	       caller, errstr, err_fn);
274 
275 	jbd2_journal_abort_handle(handle);
276 }
277 
278 /* Deal with the reporting of failure conditions on a filesystem such as
279  * inconsistencies detected or read IO failures.
280  *
281  * On ext2, we can store the error state of the filesystem in the
282  * superblock.  That is not possible on ext4, because we may have other
283  * write ordering constraints on the superblock which prevent us from
284  * writing it out straight away; and given that the journal is about to
285  * be aborted, we can't rely on the current, or future, transactions to
286  * write out the superblock safely.
287  *
288  * We'll just use the jbd2_journal_abort() error code to record an error in
289  * the journal instead.  On recovery, the journal will compain about
290  * that error until we've noted it down and cleared it.
291  */
292 
293 static void ext4_handle_error(struct super_block *sb)
294 {
295 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
296 
297 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
298 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
299 
300 	if (sb->s_flags & MS_RDONLY)
301 		return;
302 
303 	if (!test_opt(sb, ERRORS_CONT)) {
304 		journal_t *journal = EXT4_SB(sb)->s_journal;
305 
306 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
307 		if (journal)
308 			jbd2_journal_abort(journal, -EIO);
309 	}
310 	if (test_opt(sb, ERRORS_RO)) {
311 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
312 		sb->s_flags |= MS_RDONLY;
313 	}
314 	ext4_commit_super(sb, 1);
315 	if (test_opt(sb, ERRORS_PANIC))
316 		panic("EXT4-fs (device %s): panic forced after error\n",
317 			sb->s_id);
318 }
319 
320 void ext4_error(struct super_block *sb, const char *function,
321 		const char *fmt, ...)
322 {
323 	va_list args;
324 
325 	va_start(args, fmt);
326 	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
327 	vprintk(fmt, args);
328 	printk("\n");
329 	va_end(args);
330 
331 	ext4_handle_error(sb);
332 }
333 
334 static const char *ext4_decode_error(struct super_block *sb, int errno,
335 				     char nbuf[16])
336 {
337 	char *errstr = NULL;
338 
339 	switch (errno) {
340 	case -EIO:
341 		errstr = "IO failure";
342 		break;
343 	case -ENOMEM:
344 		errstr = "Out of memory";
345 		break;
346 	case -EROFS:
347 		if (!sb || EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT)
348 			errstr = "Journal has aborted";
349 		else
350 			errstr = "Readonly filesystem";
351 		break;
352 	default:
353 		/* If the caller passed in an extra buffer for unknown
354 		 * errors, textualise them now.  Else we just return
355 		 * NULL. */
356 		if (nbuf) {
357 			/* Check for truncated error codes... */
358 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
359 				errstr = nbuf;
360 		}
361 		break;
362 	}
363 
364 	return errstr;
365 }
366 
367 /* __ext4_std_error decodes expected errors from journaling functions
368  * automatically and invokes the appropriate error response.  */
369 
370 void __ext4_std_error(struct super_block *sb, const char *function, int errno)
371 {
372 	char nbuf[16];
373 	const char *errstr;
374 
375 	/* Special case: if the error is EROFS, and we're not already
376 	 * inside a transaction, then there's really no point in logging
377 	 * an error. */
378 	if (errno == -EROFS && journal_current_handle() == NULL &&
379 	    (sb->s_flags & MS_RDONLY))
380 		return;
381 
382 	errstr = ext4_decode_error(sb, errno, nbuf);
383 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
384 	       sb->s_id, function, errstr);
385 
386 	ext4_handle_error(sb);
387 }
388 
389 /*
390  * ext4_abort is a much stronger failure handler than ext4_error.  The
391  * abort function may be used to deal with unrecoverable failures such
392  * as journal IO errors or ENOMEM at a critical moment in log management.
393  *
394  * We unconditionally force the filesystem into an ABORT|READONLY state,
395  * unless the error response on the fs has been set to panic in which
396  * case we take the easy way out and panic immediately.
397  */
398 
399 void ext4_abort(struct super_block *sb, const char *function,
400 		const char *fmt, ...)
401 {
402 	va_list args;
403 
404 	va_start(args, fmt);
405 	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
406 	vprintk(fmt, args);
407 	printk("\n");
408 	va_end(args);
409 
410 	if (test_opt(sb, ERRORS_PANIC))
411 		panic("EXT4-fs panic from previous error\n");
412 
413 	if (sb->s_flags & MS_RDONLY)
414 		return;
415 
416 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
417 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
418 	sb->s_flags |= MS_RDONLY;
419 	EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
420 	if (EXT4_SB(sb)->s_journal)
421 		jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
422 }
423 
424 void ext4_msg (struct super_block * sb, const char *prefix,
425 		   const char *fmt, ...)
426 {
427 	va_list args;
428 
429 	va_start(args, fmt);
430 	printk("%sEXT4-fs (%s): ", prefix, sb->s_id);
431 	vprintk(fmt, args);
432 	printk("\n");
433 	va_end(args);
434 }
435 
436 void ext4_warning(struct super_block *sb, const char *function,
437 		  const char *fmt, ...)
438 {
439 	va_list args;
440 
441 	va_start(args, fmt);
442 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
443 	       sb->s_id, function);
444 	vprintk(fmt, args);
445 	printk("\n");
446 	va_end(args);
447 }
448 
449 void ext4_grp_locked_error(struct super_block *sb, ext4_group_t grp,
450 			   const char *function, const char *fmt, ...)
451 __releases(bitlock)
452 __acquires(bitlock)
453 {
454 	va_list args;
455 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
456 
457 	va_start(args, fmt);
458 	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
459 	vprintk(fmt, args);
460 	printk("\n");
461 	va_end(args);
462 
463 	if (test_opt(sb, ERRORS_CONT)) {
464 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
465 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
466 		ext4_commit_super(sb, 0);
467 		return;
468 	}
469 	ext4_unlock_group(sb, grp);
470 	ext4_handle_error(sb);
471 	/*
472 	 * We only get here in the ERRORS_RO case; relocking the group
473 	 * may be dangerous, but nothing bad will happen since the
474 	 * filesystem will have already been marked read/only and the
475 	 * journal has been aborted.  We return 1 as a hint to callers
476 	 * who might what to use the return value from
477 	 * ext4_grp_locked_error() to distinguish beween the
478 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
479 	 * aggressively from the ext4 function in question, with a
480 	 * more appropriate error code.
481 	 */
482 	ext4_lock_group(sb, grp);
483 	return;
484 }
485 
486 void ext4_update_dynamic_rev(struct super_block *sb)
487 {
488 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
489 
490 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
491 		return;
492 
493 	ext4_warning(sb, __func__,
494 		     "updating to rev %d because of new feature flag, "
495 		     "running e2fsck is recommended",
496 		     EXT4_DYNAMIC_REV);
497 
498 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
499 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
500 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
501 	/* leave es->s_feature_*compat flags alone */
502 	/* es->s_uuid will be set by e2fsck if empty */
503 
504 	/*
505 	 * The rest of the superblock fields should be zero, and if not it
506 	 * means they are likely already in use, so leave them alone.  We
507 	 * can leave it up to e2fsck to clean up any inconsistencies there.
508 	 */
509 }
510 
511 /*
512  * Open the external journal device
513  */
514 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
515 {
516 	struct block_device *bdev;
517 	char b[BDEVNAME_SIZE];
518 
519 	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
520 	if (IS_ERR(bdev))
521 		goto fail;
522 	return bdev;
523 
524 fail:
525 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
526 			__bdevname(dev, b), PTR_ERR(bdev));
527 	return NULL;
528 }
529 
530 /*
531  * Release the journal device
532  */
533 static int ext4_blkdev_put(struct block_device *bdev)
534 {
535 	bd_release(bdev);
536 	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
537 }
538 
539 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
540 {
541 	struct block_device *bdev;
542 	int ret = -ENODEV;
543 
544 	bdev = sbi->journal_bdev;
545 	if (bdev) {
546 		ret = ext4_blkdev_put(bdev);
547 		sbi->journal_bdev = NULL;
548 	}
549 	return ret;
550 }
551 
552 static inline struct inode *orphan_list_entry(struct list_head *l)
553 {
554 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
555 }
556 
557 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
558 {
559 	struct list_head *l;
560 
561 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
562 		 le32_to_cpu(sbi->s_es->s_last_orphan));
563 
564 	printk(KERN_ERR "sb_info orphan list:\n");
565 	list_for_each(l, &sbi->s_orphan) {
566 		struct inode *inode = orphan_list_entry(l);
567 		printk(KERN_ERR "  "
568 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
569 		       inode->i_sb->s_id, inode->i_ino, inode,
570 		       inode->i_mode, inode->i_nlink,
571 		       NEXT_ORPHAN(inode));
572 	}
573 }
574 
575 static void ext4_put_super(struct super_block *sb)
576 {
577 	struct ext4_sb_info *sbi = EXT4_SB(sb);
578 	struct ext4_super_block *es = sbi->s_es;
579 	int i, err;
580 
581 	lock_super(sb);
582 	lock_kernel();
583 	if (sb->s_dirt)
584 		ext4_commit_super(sb, 1);
585 
586 	ext4_release_system_zone(sb);
587 	ext4_mb_release(sb);
588 	ext4_ext_release(sb);
589 	ext4_xattr_put_super(sb);
590 	if (sbi->s_journal) {
591 		err = jbd2_journal_destroy(sbi->s_journal);
592 		sbi->s_journal = NULL;
593 		if (err < 0)
594 			ext4_abort(sb, __func__,
595 				   "Couldn't clean up the journal");
596 	}
597 	if (!(sb->s_flags & MS_RDONLY)) {
598 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
599 		es->s_state = cpu_to_le16(sbi->s_mount_state);
600 		ext4_commit_super(sb, 1);
601 	}
602 	if (sbi->s_proc) {
603 		remove_proc_entry(sb->s_id, ext4_proc_root);
604 	}
605 	kobject_del(&sbi->s_kobj);
606 
607 	for (i = 0; i < sbi->s_gdb_count; i++)
608 		brelse(sbi->s_group_desc[i]);
609 	kfree(sbi->s_group_desc);
610 	if (is_vmalloc_addr(sbi->s_flex_groups))
611 		vfree(sbi->s_flex_groups);
612 	else
613 		kfree(sbi->s_flex_groups);
614 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
615 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
616 	percpu_counter_destroy(&sbi->s_dirs_counter);
617 	percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
618 	brelse(sbi->s_sbh);
619 #ifdef CONFIG_QUOTA
620 	for (i = 0; i < MAXQUOTAS; i++)
621 		kfree(sbi->s_qf_names[i]);
622 #endif
623 
624 	/* Debugging code just in case the in-memory inode orphan list
625 	 * isn't empty.  The on-disk one can be non-empty if we've
626 	 * detected an error and taken the fs readonly, but the
627 	 * in-memory list had better be clean by this point. */
628 	if (!list_empty(&sbi->s_orphan))
629 		dump_orphan_list(sb, sbi);
630 	J_ASSERT(list_empty(&sbi->s_orphan));
631 
632 	invalidate_bdev(sb->s_bdev);
633 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
634 		/*
635 		 * Invalidate the journal device's buffers.  We don't want them
636 		 * floating about in memory - the physical journal device may
637 		 * hotswapped, and it breaks the `ro-after' testing code.
638 		 */
639 		sync_blockdev(sbi->journal_bdev);
640 		invalidate_bdev(sbi->journal_bdev);
641 		ext4_blkdev_remove(sbi);
642 	}
643 	sb->s_fs_info = NULL;
644 	/*
645 	 * Now that we are completely done shutting down the
646 	 * superblock, we need to actually destroy the kobject.
647 	 */
648 	unlock_kernel();
649 	unlock_super(sb);
650 	kobject_put(&sbi->s_kobj);
651 	wait_for_completion(&sbi->s_kobj_unregister);
652 	kfree(sbi->s_blockgroup_lock);
653 	kfree(sbi);
654 }
655 
656 static struct kmem_cache *ext4_inode_cachep;
657 
658 /*
659  * Called inside transaction, so use GFP_NOFS
660  */
661 static struct inode *ext4_alloc_inode(struct super_block *sb)
662 {
663 	struct ext4_inode_info *ei;
664 
665 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
666 	if (!ei)
667 		return NULL;
668 
669 	ei->vfs_inode.i_version = 1;
670 	ei->vfs_inode.i_data.writeback_index = 0;
671 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
672 	INIT_LIST_HEAD(&ei->i_prealloc_list);
673 	spin_lock_init(&ei->i_prealloc_lock);
674 	/*
675 	 * Note:  We can be called before EXT4_SB(sb)->s_journal is set,
676 	 * therefore it can be null here.  Don't check it, just initialize
677 	 * jinode.
678 	 */
679 	jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
680 	ei->i_reserved_data_blocks = 0;
681 	ei->i_reserved_meta_blocks = 0;
682 	ei->i_allocated_meta_blocks = 0;
683 	ei->i_delalloc_reserved_flag = 0;
684 	spin_lock_init(&(ei->i_block_reservation_lock));
685 
686 	return &ei->vfs_inode;
687 }
688 
689 static void ext4_destroy_inode(struct inode *inode)
690 {
691 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
692 		ext4_msg(inode->i_sb, KERN_ERR,
693 			 "Inode %lu (%p): orphan list check failed!",
694 			 inode->i_ino, EXT4_I(inode));
695 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
696 				EXT4_I(inode), sizeof(struct ext4_inode_info),
697 				true);
698 		dump_stack();
699 	}
700 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
701 }
702 
703 static void init_once(void *foo)
704 {
705 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
706 
707 	INIT_LIST_HEAD(&ei->i_orphan);
708 #ifdef CONFIG_EXT4_FS_XATTR
709 	init_rwsem(&ei->xattr_sem);
710 #endif
711 	init_rwsem(&ei->i_data_sem);
712 	inode_init_once(&ei->vfs_inode);
713 }
714 
715 static int init_inodecache(void)
716 {
717 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
718 					     sizeof(struct ext4_inode_info),
719 					     0, (SLAB_RECLAIM_ACCOUNT|
720 						SLAB_MEM_SPREAD),
721 					     init_once);
722 	if (ext4_inode_cachep == NULL)
723 		return -ENOMEM;
724 	return 0;
725 }
726 
727 static void destroy_inodecache(void)
728 {
729 	kmem_cache_destroy(ext4_inode_cachep);
730 }
731 
732 static void ext4_clear_inode(struct inode *inode)
733 {
734 	ext4_discard_preallocations(inode);
735 	if (EXT4_JOURNAL(inode))
736 		jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
737 				       &EXT4_I(inode)->jinode);
738 }
739 
740 static inline void ext4_show_quota_options(struct seq_file *seq,
741 					   struct super_block *sb)
742 {
743 #if defined(CONFIG_QUOTA)
744 	struct ext4_sb_info *sbi = EXT4_SB(sb);
745 
746 	if (sbi->s_jquota_fmt)
747 		seq_printf(seq, ",jqfmt=%s",
748 		(sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold" : "vfsv0");
749 
750 	if (sbi->s_qf_names[USRQUOTA])
751 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
752 
753 	if (sbi->s_qf_names[GRPQUOTA])
754 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
755 
756 	if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
757 		seq_puts(seq, ",usrquota");
758 
759 	if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
760 		seq_puts(seq, ",grpquota");
761 #endif
762 }
763 
764 /*
765  * Show an option if
766  *  - it's set to a non-default value OR
767  *  - if the per-sb default is different from the global default
768  */
769 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
770 {
771 	int def_errors;
772 	unsigned long def_mount_opts;
773 	struct super_block *sb = vfs->mnt_sb;
774 	struct ext4_sb_info *sbi = EXT4_SB(sb);
775 	struct ext4_super_block *es = sbi->s_es;
776 
777 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
778 	def_errors     = le16_to_cpu(es->s_errors);
779 
780 	if (sbi->s_sb_block != 1)
781 		seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
782 	if (test_opt(sb, MINIX_DF))
783 		seq_puts(seq, ",minixdf");
784 	if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
785 		seq_puts(seq, ",grpid");
786 	if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
787 		seq_puts(seq, ",nogrpid");
788 	if (sbi->s_resuid != EXT4_DEF_RESUID ||
789 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
790 		seq_printf(seq, ",resuid=%u", sbi->s_resuid);
791 	}
792 	if (sbi->s_resgid != EXT4_DEF_RESGID ||
793 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
794 		seq_printf(seq, ",resgid=%u", sbi->s_resgid);
795 	}
796 	if (test_opt(sb, ERRORS_RO)) {
797 		if (def_errors == EXT4_ERRORS_PANIC ||
798 		    def_errors == EXT4_ERRORS_CONTINUE) {
799 			seq_puts(seq, ",errors=remount-ro");
800 		}
801 	}
802 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
803 		seq_puts(seq, ",errors=continue");
804 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
805 		seq_puts(seq, ",errors=panic");
806 	if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
807 		seq_puts(seq, ",nouid32");
808 	if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
809 		seq_puts(seq, ",debug");
810 	if (test_opt(sb, OLDALLOC))
811 		seq_puts(seq, ",oldalloc");
812 #ifdef CONFIG_EXT4_FS_XATTR
813 	if (test_opt(sb, XATTR_USER) &&
814 		!(def_mount_opts & EXT4_DEFM_XATTR_USER))
815 		seq_puts(seq, ",user_xattr");
816 	if (!test_opt(sb, XATTR_USER) &&
817 	    (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
818 		seq_puts(seq, ",nouser_xattr");
819 	}
820 #endif
821 #ifdef CONFIG_EXT4_FS_POSIX_ACL
822 	if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
823 		seq_puts(seq, ",acl");
824 	if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
825 		seq_puts(seq, ",noacl");
826 #endif
827 	if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
828 		seq_printf(seq, ",commit=%u",
829 			   (unsigned) (sbi->s_commit_interval / HZ));
830 	}
831 	if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
832 		seq_printf(seq, ",min_batch_time=%u",
833 			   (unsigned) sbi->s_min_batch_time);
834 	}
835 	if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
836 		seq_printf(seq, ",max_batch_time=%u",
837 			   (unsigned) sbi->s_min_batch_time);
838 	}
839 
840 	/*
841 	 * We're changing the default of barrier mount option, so
842 	 * let's always display its mount state so it's clear what its
843 	 * status is.
844 	 */
845 	seq_puts(seq, ",barrier=");
846 	seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
847 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
848 		seq_puts(seq, ",journal_async_commit");
849 	if (test_opt(sb, NOBH))
850 		seq_puts(seq, ",nobh");
851 	if (test_opt(sb, I_VERSION))
852 		seq_puts(seq, ",i_version");
853 	if (!test_opt(sb, DELALLOC))
854 		seq_puts(seq, ",nodelalloc");
855 
856 
857 	if (sbi->s_stripe)
858 		seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
859 	/*
860 	 * journal mode get enabled in different ways
861 	 * So just print the value even if we didn't specify it
862 	 */
863 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
864 		seq_puts(seq, ",data=journal");
865 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
866 		seq_puts(seq, ",data=ordered");
867 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
868 		seq_puts(seq, ",data=writeback");
869 
870 	if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
871 		seq_printf(seq, ",inode_readahead_blks=%u",
872 			   sbi->s_inode_readahead_blks);
873 
874 	if (test_opt(sb, DATA_ERR_ABORT))
875 		seq_puts(seq, ",data_err=abort");
876 
877 	if (test_opt(sb, NO_AUTO_DA_ALLOC))
878 		seq_puts(seq, ",noauto_da_alloc");
879 
880 	ext4_show_quota_options(seq, sb);
881 
882 	return 0;
883 }
884 
885 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
886 					u64 ino, u32 generation)
887 {
888 	struct inode *inode;
889 
890 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
891 		return ERR_PTR(-ESTALE);
892 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
893 		return ERR_PTR(-ESTALE);
894 
895 	/* iget isn't really right if the inode is currently unallocated!!
896 	 *
897 	 * ext4_read_inode will return a bad_inode if the inode had been
898 	 * deleted, so we should be safe.
899 	 *
900 	 * Currently we don't know the generation for parent directory, so
901 	 * a generation of 0 means "accept any"
902 	 */
903 	inode = ext4_iget(sb, ino);
904 	if (IS_ERR(inode))
905 		return ERR_CAST(inode);
906 	if (generation && inode->i_generation != generation) {
907 		iput(inode);
908 		return ERR_PTR(-ESTALE);
909 	}
910 
911 	return inode;
912 }
913 
914 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
915 					int fh_len, int fh_type)
916 {
917 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
918 				    ext4_nfs_get_inode);
919 }
920 
921 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
922 					int fh_len, int fh_type)
923 {
924 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
925 				    ext4_nfs_get_inode);
926 }
927 
928 /*
929  * Try to release metadata pages (indirect blocks, directories) which are
930  * mapped via the block device.  Since these pages could have journal heads
931  * which would prevent try_to_free_buffers() from freeing them, we must use
932  * jbd2 layer's try_to_free_buffers() function to release them.
933  */
934 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
935 				 gfp_t wait)
936 {
937 	journal_t *journal = EXT4_SB(sb)->s_journal;
938 
939 	WARN_ON(PageChecked(page));
940 	if (!page_has_buffers(page))
941 		return 0;
942 	if (journal)
943 		return jbd2_journal_try_to_free_buffers(journal, page,
944 							wait & ~__GFP_WAIT);
945 	return try_to_free_buffers(page);
946 }
947 
948 #ifdef CONFIG_QUOTA
949 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
950 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
951 
952 static int ext4_write_dquot(struct dquot *dquot);
953 static int ext4_acquire_dquot(struct dquot *dquot);
954 static int ext4_release_dquot(struct dquot *dquot);
955 static int ext4_mark_dquot_dirty(struct dquot *dquot);
956 static int ext4_write_info(struct super_block *sb, int type);
957 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
958 				char *path, int remount);
959 static int ext4_quota_on_mount(struct super_block *sb, int type);
960 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
961 			       size_t len, loff_t off);
962 static ssize_t ext4_quota_write(struct super_block *sb, int type,
963 				const char *data, size_t len, loff_t off);
964 
965 static struct dquot_operations ext4_quota_operations = {
966 	.initialize	= dquot_initialize,
967 	.drop		= dquot_drop,
968 	.alloc_space	= dquot_alloc_space,
969 	.reserve_space	= dquot_reserve_space,
970 	.claim_space	= dquot_claim_space,
971 	.release_rsv	= dquot_release_reserved_space,
972 	.get_reserved_space = ext4_get_reserved_space,
973 	.alloc_inode	= dquot_alloc_inode,
974 	.free_space	= dquot_free_space,
975 	.free_inode	= dquot_free_inode,
976 	.transfer	= dquot_transfer,
977 	.write_dquot	= ext4_write_dquot,
978 	.acquire_dquot	= ext4_acquire_dquot,
979 	.release_dquot	= ext4_release_dquot,
980 	.mark_dirty	= ext4_mark_dquot_dirty,
981 	.write_info	= ext4_write_info,
982 	.alloc_dquot	= dquot_alloc,
983 	.destroy_dquot	= dquot_destroy,
984 };
985 
986 static struct quotactl_ops ext4_qctl_operations = {
987 	.quota_on	= ext4_quota_on,
988 	.quota_off	= vfs_quota_off,
989 	.quota_sync	= vfs_quota_sync,
990 	.get_info	= vfs_get_dqinfo,
991 	.set_info	= vfs_set_dqinfo,
992 	.get_dqblk	= vfs_get_dqblk,
993 	.set_dqblk	= vfs_set_dqblk
994 };
995 #endif
996 
997 static const struct super_operations ext4_sops = {
998 	.alloc_inode	= ext4_alloc_inode,
999 	.destroy_inode	= ext4_destroy_inode,
1000 	.write_inode	= ext4_write_inode,
1001 	.dirty_inode	= ext4_dirty_inode,
1002 	.delete_inode	= ext4_delete_inode,
1003 	.put_super	= ext4_put_super,
1004 	.sync_fs	= ext4_sync_fs,
1005 	.freeze_fs	= ext4_freeze,
1006 	.unfreeze_fs	= ext4_unfreeze,
1007 	.statfs		= ext4_statfs,
1008 	.remount_fs	= ext4_remount,
1009 	.clear_inode	= ext4_clear_inode,
1010 	.show_options	= ext4_show_options,
1011 #ifdef CONFIG_QUOTA
1012 	.quota_read	= ext4_quota_read,
1013 	.quota_write	= ext4_quota_write,
1014 #endif
1015 	.bdev_try_to_free_page = bdev_try_to_free_page,
1016 };
1017 
1018 static const struct super_operations ext4_nojournal_sops = {
1019 	.alloc_inode	= ext4_alloc_inode,
1020 	.destroy_inode	= ext4_destroy_inode,
1021 	.write_inode	= ext4_write_inode,
1022 	.dirty_inode	= ext4_dirty_inode,
1023 	.delete_inode	= ext4_delete_inode,
1024 	.write_super	= ext4_write_super,
1025 	.put_super	= ext4_put_super,
1026 	.statfs		= ext4_statfs,
1027 	.remount_fs	= ext4_remount,
1028 	.clear_inode	= ext4_clear_inode,
1029 	.show_options	= ext4_show_options,
1030 #ifdef CONFIG_QUOTA
1031 	.quota_read	= ext4_quota_read,
1032 	.quota_write	= ext4_quota_write,
1033 #endif
1034 	.bdev_try_to_free_page = bdev_try_to_free_page,
1035 };
1036 
1037 static const struct export_operations ext4_export_ops = {
1038 	.fh_to_dentry = ext4_fh_to_dentry,
1039 	.fh_to_parent = ext4_fh_to_parent,
1040 	.get_parent = ext4_get_parent,
1041 };
1042 
1043 enum {
1044 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1045 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1046 	Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1047 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1048 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1049 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1050 	Opt_journal_update, Opt_journal_dev,
1051 	Opt_journal_checksum, Opt_journal_async_commit,
1052 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1053 	Opt_data_err_abort, Opt_data_err_ignore, Opt_mb_history_length,
1054 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1055 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
1056 	Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err, Opt_resize,
1057 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1058 	Opt_stripe, Opt_delalloc, Opt_nodelalloc,
1059 	Opt_block_validity, Opt_noblock_validity,
1060 	Opt_inode_readahead_blks, Opt_journal_ioprio
1061 };
1062 
1063 static const match_table_t tokens = {
1064 	{Opt_bsd_df, "bsddf"},
1065 	{Opt_minix_df, "minixdf"},
1066 	{Opt_grpid, "grpid"},
1067 	{Opt_grpid, "bsdgroups"},
1068 	{Opt_nogrpid, "nogrpid"},
1069 	{Opt_nogrpid, "sysvgroups"},
1070 	{Opt_resgid, "resgid=%u"},
1071 	{Opt_resuid, "resuid=%u"},
1072 	{Opt_sb, "sb=%u"},
1073 	{Opt_err_cont, "errors=continue"},
1074 	{Opt_err_panic, "errors=panic"},
1075 	{Opt_err_ro, "errors=remount-ro"},
1076 	{Opt_nouid32, "nouid32"},
1077 	{Opt_debug, "debug"},
1078 	{Opt_oldalloc, "oldalloc"},
1079 	{Opt_orlov, "orlov"},
1080 	{Opt_user_xattr, "user_xattr"},
1081 	{Opt_nouser_xattr, "nouser_xattr"},
1082 	{Opt_acl, "acl"},
1083 	{Opt_noacl, "noacl"},
1084 	{Opt_noload, "noload"},
1085 	{Opt_nobh, "nobh"},
1086 	{Opt_bh, "bh"},
1087 	{Opt_commit, "commit=%u"},
1088 	{Opt_min_batch_time, "min_batch_time=%u"},
1089 	{Opt_max_batch_time, "max_batch_time=%u"},
1090 	{Opt_journal_update, "journal=update"},
1091 	{Opt_journal_dev, "journal_dev=%u"},
1092 	{Opt_journal_checksum, "journal_checksum"},
1093 	{Opt_journal_async_commit, "journal_async_commit"},
1094 	{Opt_abort, "abort"},
1095 	{Opt_data_journal, "data=journal"},
1096 	{Opt_data_ordered, "data=ordered"},
1097 	{Opt_data_writeback, "data=writeback"},
1098 	{Opt_data_err_abort, "data_err=abort"},
1099 	{Opt_data_err_ignore, "data_err=ignore"},
1100 	{Opt_mb_history_length, "mb_history_length=%u"},
1101 	{Opt_offusrjquota, "usrjquota="},
1102 	{Opt_usrjquota, "usrjquota=%s"},
1103 	{Opt_offgrpjquota, "grpjquota="},
1104 	{Opt_grpjquota, "grpjquota=%s"},
1105 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1106 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1107 	{Opt_grpquota, "grpquota"},
1108 	{Opt_noquota, "noquota"},
1109 	{Opt_quota, "quota"},
1110 	{Opt_usrquota, "usrquota"},
1111 	{Opt_barrier, "barrier=%u"},
1112 	{Opt_barrier, "barrier"},
1113 	{Opt_nobarrier, "nobarrier"},
1114 	{Opt_i_version, "i_version"},
1115 	{Opt_stripe, "stripe=%u"},
1116 	{Opt_resize, "resize"},
1117 	{Opt_delalloc, "delalloc"},
1118 	{Opt_nodelalloc, "nodelalloc"},
1119 	{Opt_block_validity, "block_validity"},
1120 	{Opt_noblock_validity, "noblock_validity"},
1121 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1122 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1123 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1124 	{Opt_auto_da_alloc, "auto_da_alloc"},
1125 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1126 	{Opt_err, NULL},
1127 };
1128 
1129 static ext4_fsblk_t get_sb_block(void **data)
1130 {
1131 	ext4_fsblk_t	sb_block;
1132 	char		*options = (char *) *data;
1133 
1134 	if (!options || strncmp(options, "sb=", 3) != 0)
1135 		return 1;	/* Default location */
1136 
1137 	options += 3;
1138 	/* TODO: use simple_strtoll with >32bit ext4 */
1139 	sb_block = simple_strtoul(options, &options, 0);
1140 	if (*options && *options != ',') {
1141 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1142 		       (char *) *data);
1143 		return 1;
1144 	}
1145 	if (*options == ',')
1146 		options++;
1147 	*data = (void *) options;
1148 
1149 	return sb_block;
1150 }
1151 
1152 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1153 
1154 static int parse_options(char *options, struct super_block *sb,
1155 			 unsigned long *journal_devnum,
1156 			 unsigned int *journal_ioprio,
1157 			 ext4_fsblk_t *n_blocks_count, int is_remount)
1158 {
1159 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1160 	char *p;
1161 	substring_t args[MAX_OPT_ARGS];
1162 	int data_opt = 0;
1163 	int option;
1164 #ifdef CONFIG_QUOTA
1165 	int qtype, qfmt;
1166 	char *qname;
1167 #endif
1168 
1169 	if (!options)
1170 		return 1;
1171 
1172 	while ((p = strsep(&options, ",")) != NULL) {
1173 		int token;
1174 		if (!*p)
1175 			continue;
1176 
1177 		token = match_token(p, tokens, args);
1178 		switch (token) {
1179 		case Opt_bsd_df:
1180 			clear_opt(sbi->s_mount_opt, MINIX_DF);
1181 			break;
1182 		case Opt_minix_df:
1183 			set_opt(sbi->s_mount_opt, MINIX_DF);
1184 			break;
1185 		case Opt_grpid:
1186 			set_opt(sbi->s_mount_opt, GRPID);
1187 			break;
1188 		case Opt_nogrpid:
1189 			clear_opt(sbi->s_mount_opt, GRPID);
1190 			break;
1191 		case Opt_resuid:
1192 			if (match_int(&args[0], &option))
1193 				return 0;
1194 			sbi->s_resuid = option;
1195 			break;
1196 		case Opt_resgid:
1197 			if (match_int(&args[0], &option))
1198 				return 0;
1199 			sbi->s_resgid = option;
1200 			break;
1201 		case Opt_sb:
1202 			/* handled by get_sb_block() instead of here */
1203 			/* *sb_block = match_int(&args[0]); */
1204 			break;
1205 		case Opt_err_panic:
1206 			clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1207 			clear_opt(sbi->s_mount_opt, ERRORS_RO);
1208 			set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1209 			break;
1210 		case Opt_err_ro:
1211 			clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1212 			clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1213 			set_opt(sbi->s_mount_opt, ERRORS_RO);
1214 			break;
1215 		case Opt_err_cont:
1216 			clear_opt(sbi->s_mount_opt, ERRORS_RO);
1217 			clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1218 			set_opt(sbi->s_mount_opt, ERRORS_CONT);
1219 			break;
1220 		case Opt_nouid32:
1221 			set_opt(sbi->s_mount_opt, NO_UID32);
1222 			break;
1223 		case Opt_debug:
1224 			set_opt(sbi->s_mount_opt, DEBUG);
1225 			break;
1226 		case Opt_oldalloc:
1227 			set_opt(sbi->s_mount_opt, OLDALLOC);
1228 			break;
1229 		case Opt_orlov:
1230 			clear_opt(sbi->s_mount_opt, OLDALLOC);
1231 			break;
1232 #ifdef CONFIG_EXT4_FS_XATTR
1233 		case Opt_user_xattr:
1234 			set_opt(sbi->s_mount_opt, XATTR_USER);
1235 			break;
1236 		case Opt_nouser_xattr:
1237 			clear_opt(sbi->s_mount_opt, XATTR_USER);
1238 			break;
1239 #else
1240 		case Opt_user_xattr:
1241 		case Opt_nouser_xattr:
1242 			ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1243 			break;
1244 #endif
1245 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1246 		case Opt_acl:
1247 			set_opt(sbi->s_mount_opt, POSIX_ACL);
1248 			break;
1249 		case Opt_noacl:
1250 			clear_opt(sbi->s_mount_opt, POSIX_ACL);
1251 			break;
1252 #else
1253 		case Opt_acl:
1254 		case Opt_noacl:
1255 			ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1256 			break;
1257 #endif
1258 		case Opt_journal_update:
1259 			/* @@@ FIXME */
1260 			/* Eventually we will want to be able to create
1261 			   a journal file here.  For now, only allow the
1262 			   user to specify an existing inode to be the
1263 			   journal file. */
1264 			if (is_remount) {
1265 				ext4_msg(sb, KERN_ERR,
1266 					 "Cannot specify journal on remount");
1267 				return 0;
1268 			}
1269 			set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1270 			break;
1271 		case Opt_journal_dev:
1272 			if (is_remount) {
1273 				ext4_msg(sb, KERN_ERR,
1274 					"Cannot specify journal on remount");
1275 				return 0;
1276 			}
1277 			if (match_int(&args[0], &option))
1278 				return 0;
1279 			*journal_devnum = option;
1280 			break;
1281 		case Opt_journal_checksum:
1282 			set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1283 			break;
1284 		case Opt_journal_async_commit:
1285 			set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1286 			set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
1287 			break;
1288 		case Opt_noload:
1289 			set_opt(sbi->s_mount_opt, NOLOAD);
1290 			break;
1291 		case Opt_commit:
1292 			if (match_int(&args[0], &option))
1293 				return 0;
1294 			if (option < 0)
1295 				return 0;
1296 			if (option == 0)
1297 				option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1298 			sbi->s_commit_interval = HZ * option;
1299 			break;
1300 		case Opt_max_batch_time:
1301 			if (match_int(&args[0], &option))
1302 				return 0;
1303 			if (option < 0)
1304 				return 0;
1305 			if (option == 0)
1306 				option = EXT4_DEF_MAX_BATCH_TIME;
1307 			sbi->s_max_batch_time = option;
1308 			break;
1309 		case Opt_min_batch_time:
1310 			if (match_int(&args[0], &option))
1311 				return 0;
1312 			if (option < 0)
1313 				return 0;
1314 			sbi->s_min_batch_time = option;
1315 			break;
1316 		case Opt_data_journal:
1317 			data_opt = EXT4_MOUNT_JOURNAL_DATA;
1318 			goto datacheck;
1319 		case Opt_data_ordered:
1320 			data_opt = EXT4_MOUNT_ORDERED_DATA;
1321 			goto datacheck;
1322 		case Opt_data_writeback:
1323 			data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1324 		datacheck:
1325 			if (is_remount) {
1326 				if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1327 						!= data_opt) {
1328 					ext4_msg(sb, KERN_ERR,
1329 						"Cannot change data mode on remount");
1330 					return 0;
1331 				}
1332 			} else {
1333 				sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1334 				sbi->s_mount_opt |= data_opt;
1335 			}
1336 			break;
1337 		case Opt_data_err_abort:
1338 			set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1339 			break;
1340 		case Opt_data_err_ignore:
1341 			clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1342 			break;
1343 		case Opt_mb_history_length:
1344 			if (match_int(&args[0], &option))
1345 				return 0;
1346 			if (option < 0)
1347 				return 0;
1348 			sbi->s_mb_history_max = option;
1349 			break;
1350 #ifdef CONFIG_QUOTA
1351 		case Opt_usrjquota:
1352 			qtype = USRQUOTA;
1353 			goto set_qf_name;
1354 		case Opt_grpjquota:
1355 			qtype = GRPQUOTA;
1356 set_qf_name:
1357 			if (sb_any_quota_loaded(sb) &&
1358 			    !sbi->s_qf_names[qtype]) {
1359 				ext4_msg(sb, KERN_ERR,
1360 				       "Cannot change journaled "
1361 				       "quota options when quota turned on");
1362 				return 0;
1363 			}
1364 			qname = match_strdup(&args[0]);
1365 			if (!qname) {
1366 				ext4_msg(sb, KERN_ERR,
1367 					"Not enough memory for "
1368 					"storing quotafile name");
1369 				return 0;
1370 			}
1371 			if (sbi->s_qf_names[qtype] &&
1372 			    strcmp(sbi->s_qf_names[qtype], qname)) {
1373 				ext4_msg(sb, KERN_ERR,
1374 					"%s quota file already "
1375 					"specified", QTYPE2NAME(qtype));
1376 				kfree(qname);
1377 				return 0;
1378 			}
1379 			sbi->s_qf_names[qtype] = qname;
1380 			if (strchr(sbi->s_qf_names[qtype], '/')) {
1381 				ext4_msg(sb, KERN_ERR,
1382 					"quotafile must be on "
1383 					"filesystem root");
1384 				kfree(sbi->s_qf_names[qtype]);
1385 				sbi->s_qf_names[qtype] = NULL;
1386 				return 0;
1387 			}
1388 			set_opt(sbi->s_mount_opt, QUOTA);
1389 			break;
1390 		case Opt_offusrjquota:
1391 			qtype = USRQUOTA;
1392 			goto clear_qf_name;
1393 		case Opt_offgrpjquota:
1394 			qtype = GRPQUOTA;
1395 clear_qf_name:
1396 			if (sb_any_quota_loaded(sb) &&
1397 			    sbi->s_qf_names[qtype]) {
1398 				ext4_msg(sb, KERN_ERR, "Cannot change "
1399 					"journaled quota options when "
1400 					"quota turned on");
1401 				return 0;
1402 			}
1403 			/*
1404 			 * The space will be released later when all options
1405 			 * are confirmed to be correct
1406 			 */
1407 			sbi->s_qf_names[qtype] = NULL;
1408 			break;
1409 		case Opt_jqfmt_vfsold:
1410 			qfmt = QFMT_VFS_OLD;
1411 			goto set_qf_format;
1412 		case Opt_jqfmt_vfsv0:
1413 			qfmt = QFMT_VFS_V0;
1414 set_qf_format:
1415 			if (sb_any_quota_loaded(sb) &&
1416 			    sbi->s_jquota_fmt != qfmt) {
1417 				ext4_msg(sb, KERN_ERR, "Cannot change "
1418 					"journaled quota options when "
1419 					"quota turned on");
1420 				return 0;
1421 			}
1422 			sbi->s_jquota_fmt = qfmt;
1423 			break;
1424 		case Opt_quota:
1425 		case Opt_usrquota:
1426 			set_opt(sbi->s_mount_opt, QUOTA);
1427 			set_opt(sbi->s_mount_opt, USRQUOTA);
1428 			break;
1429 		case Opt_grpquota:
1430 			set_opt(sbi->s_mount_opt, QUOTA);
1431 			set_opt(sbi->s_mount_opt, GRPQUOTA);
1432 			break;
1433 		case Opt_noquota:
1434 			if (sb_any_quota_loaded(sb)) {
1435 				ext4_msg(sb, KERN_ERR, "Cannot change quota "
1436 					"options when quota turned on");
1437 				return 0;
1438 			}
1439 			clear_opt(sbi->s_mount_opt, QUOTA);
1440 			clear_opt(sbi->s_mount_opt, USRQUOTA);
1441 			clear_opt(sbi->s_mount_opt, GRPQUOTA);
1442 			break;
1443 #else
1444 		case Opt_quota:
1445 		case Opt_usrquota:
1446 		case Opt_grpquota:
1447 			ext4_msg(sb, KERN_ERR,
1448 				"quota options not supported");
1449 			break;
1450 		case Opt_usrjquota:
1451 		case Opt_grpjquota:
1452 		case Opt_offusrjquota:
1453 		case Opt_offgrpjquota:
1454 		case Opt_jqfmt_vfsold:
1455 		case Opt_jqfmt_vfsv0:
1456 			ext4_msg(sb, KERN_ERR,
1457 				"journaled quota options not supported");
1458 			break;
1459 		case Opt_noquota:
1460 			break;
1461 #endif
1462 		case Opt_abort:
1463 			sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1464 			break;
1465 		case Opt_nobarrier:
1466 			clear_opt(sbi->s_mount_opt, BARRIER);
1467 			break;
1468 		case Opt_barrier:
1469 			if (match_int(&args[0], &option)) {
1470 				set_opt(sbi->s_mount_opt, BARRIER);
1471 				break;
1472 			}
1473 			if (option)
1474 				set_opt(sbi->s_mount_opt, BARRIER);
1475 			else
1476 				clear_opt(sbi->s_mount_opt, BARRIER);
1477 			break;
1478 		case Opt_ignore:
1479 			break;
1480 		case Opt_resize:
1481 			if (!is_remount) {
1482 				ext4_msg(sb, KERN_ERR,
1483 					"resize option only available "
1484 					"for remount");
1485 				return 0;
1486 			}
1487 			if (match_int(&args[0], &option) != 0)
1488 				return 0;
1489 			*n_blocks_count = option;
1490 			break;
1491 		case Opt_nobh:
1492 			set_opt(sbi->s_mount_opt, NOBH);
1493 			break;
1494 		case Opt_bh:
1495 			clear_opt(sbi->s_mount_opt, NOBH);
1496 			break;
1497 		case Opt_i_version:
1498 			set_opt(sbi->s_mount_opt, I_VERSION);
1499 			sb->s_flags |= MS_I_VERSION;
1500 			break;
1501 		case Opt_nodelalloc:
1502 			clear_opt(sbi->s_mount_opt, DELALLOC);
1503 			break;
1504 		case Opt_stripe:
1505 			if (match_int(&args[0], &option))
1506 				return 0;
1507 			if (option < 0)
1508 				return 0;
1509 			sbi->s_stripe = option;
1510 			break;
1511 		case Opt_delalloc:
1512 			set_opt(sbi->s_mount_opt, DELALLOC);
1513 			break;
1514 		case Opt_block_validity:
1515 			set_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1516 			break;
1517 		case Opt_noblock_validity:
1518 			clear_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1519 			break;
1520 		case Opt_inode_readahead_blks:
1521 			if (match_int(&args[0], &option))
1522 				return 0;
1523 			if (option < 0 || option > (1 << 30))
1524 				return 0;
1525 			if (!is_power_of_2(option)) {
1526 				ext4_msg(sb, KERN_ERR,
1527 					 "EXT4-fs: inode_readahead_blks"
1528 					 " must be a power of 2");
1529 				return 0;
1530 			}
1531 			sbi->s_inode_readahead_blks = option;
1532 			break;
1533 		case Opt_journal_ioprio:
1534 			if (match_int(&args[0], &option))
1535 				return 0;
1536 			if (option < 0 || option > 7)
1537 				break;
1538 			*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1539 							    option);
1540 			break;
1541 		case Opt_noauto_da_alloc:
1542 			set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1543 			break;
1544 		case Opt_auto_da_alloc:
1545 			if (match_int(&args[0], &option)) {
1546 				clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1547 				break;
1548 			}
1549 			if (option)
1550 				clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1551 			else
1552 				set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1553 			break;
1554 		default:
1555 			ext4_msg(sb, KERN_ERR,
1556 			       "Unrecognized mount option \"%s\" "
1557 			       "or missing value", p);
1558 			return 0;
1559 		}
1560 	}
1561 #ifdef CONFIG_QUOTA
1562 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1563 		if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1564 		     sbi->s_qf_names[USRQUOTA])
1565 			clear_opt(sbi->s_mount_opt, USRQUOTA);
1566 
1567 		if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1568 		     sbi->s_qf_names[GRPQUOTA])
1569 			clear_opt(sbi->s_mount_opt, GRPQUOTA);
1570 
1571 		if ((sbi->s_qf_names[USRQUOTA] &&
1572 				(sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1573 		    (sbi->s_qf_names[GRPQUOTA] &&
1574 				(sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1575 			ext4_msg(sb, KERN_ERR, "old and new quota "
1576 					"format mixing");
1577 			return 0;
1578 		}
1579 
1580 		if (!sbi->s_jquota_fmt) {
1581 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1582 					"not specified");
1583 			return 0;
1584 		}
1585 	} else {
1586 		if (sbi->s_jquota_fmt) {
1587 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1588 					"specified with no journaling "
1589 					"enabled");
1590 			return 0;
1591 		}
1592 	}
1593 #endif
1594 	return 1;
1595 }
1596 
1597 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1598 			    int read_only)
1599 {
1600 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1601 	int res = 0;
1602 
1603 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1604 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1605 			 "forcing read-only mode");
1606 		res = MS_RDONLY;
1607 	}
1608 	if (read_only)
1609 		return res;
1610 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1611 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1612 			 "running e2fsck is recommended");
1613 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1614 		ext4_msg(sb, KERN_WARNING,
1615 			 "warning: mounting fs with errors, "
1616 			 "running e2fsck is recommended");
1617 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1618 		 le16_to_cpu(es->s_mnt_count) >=
1619 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1620 		ext4_msg(sb, KERN_WARNING,
1621 			 "warning: maximal mount count reached, "
1622 			 "running e2fsck is recommended");
1623 	else if (le32_to_cpu(es->s_checkinterval) &&
1624 		(le32_to_cpu(es->s_lastcheck) +
1625 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1626 		ext4_msg(sb, KERN_WARNING,
1627 			 "warning: checktime reached, "
1628 			 "running e2fsck is recommended");
1629 	if (!sbi->s_journal)
1630 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1631 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1632 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1633 	le16_add_cpu(&es->s_mnt_count, 1);
1634 	es->s_mtime = cpu_to_le32(get_seconds());
1635 	ext4_update_dynamic_rev(sb);
1636 	if (sbi->s_journal)
1637 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1638 
1639 	ext4_commit_super(sb, 1);
1640 	if (test_opt(sb, DEBUG))
1641 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1642 				"bpg=%lu, ipg=%lu, mo=%04x]\n",
1643 			sb->s_blocksize,
1644 			sbi->s_groups_count,
1645 			EXT4_BLOCKS_PER_GROUP(sb),
1646 			EXT4_INODES_PER_GROUP(sb),
1647 			sbi->s_mount_opt);
1648 
1649 	if (EXT4_SB(sb)->s_journal) {
1650 		ext4_msg(sb, KERN_INFO, "%s journal on %s",
1651 		       EXT4_SB(sb)->s_journal->j_inode ? "internal" :
1652 		       "external", EXT4_SB(sb)->s_journal->j_devname);
1653 	} else {
1654 		ext4_msg(sb, KERN_INFO, "no journal");
1655 	}
1656 	return res;
1657 }
1658 
1659 static int ext4_fill_flex_info(struct super_block *sb)
1660 {
1661 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1662 	struct ext4_group_desc *gdp = NULL;
1663 	ext4_group_t flex_group_count;
1664 	ext4_group_t flex_group;
1665 	int groups_per_flex = 0;
1666 	size_t size;
1667 	int i;
1668 
1669 	if (!sbi->s_es->s_log_groups_per_flex) {
1670 		sbi->s_log_groups_per_flex = 0;
1671 		return 1;
1672 	}
1673 
1674 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1675 	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1676 
1677 	/* We allocate both existing and potentially added groups */
1678 	flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1679 			((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1680 			      EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1681 	size = flex_group_count * sizeof(struct flex_groups);
1682 	sbi->s_flex_groups = kzalloc(size, GFP_KERNEL);
1683 	if (sbi->s_flex_groups == NULL) {
1684 		sbi->s_flex_groups = vmalloc(size);
1685 		if (sbi->s_flex_groups)
1686 			memset(sbi->s_flex_groups, 0, size);
1687 	}
1688 	if (sbi->s_flex_groups == NULL) {
1689 		ext4_msg(sb, KERN_ERR, "not enough memory for "
1690 				"%u flex groups", flex_group_count);
1691 		goto failed;
1692 	}
1693 
1694 	for (i = 0; i < sbi->s_groups_count; i++) {
1695 		gdp = ext4_get_group_desc(sb, i, NULL);
1696 
1697 		flex_group = ext4_flex_group(sbi, i);
1698 		atomic_set(&sbi->s_flex_groups[flex_group].free_inodes,
1699 			   ext4_free_inodes_count(sb, gdp));
1700 		atomic_set(&sbi->s_flex_groups[flex_group].free_blocks,
1701 			   ext4_free_blks_count(sb, gdp));
1702 		atomic_set(&sbi->s_flex_groups[flex_group].used_dirs,
1703 			   ext4_used_dirs_count(sb, gdp));
1704 	}
1705 
1706 	return 1;
1707 failed:
1708 	return 0;
1709 }
1710 
1711 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1712 			    struct ext4_group_desc *gdp)
1713 {
1714 	__u16 crc = 0;
1715 
1716 	if (sbi->s_es->s_feature_ro_compat &
1717 	    cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1718 		int offset = offsetof(struct ext4_group_desc, bg_checksum);
1719 		__le32 le_group = cpu_to_le32(block_group);
1720 
1721 		crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1722 		crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1723 		crc = crc16(crc, (__u8 *)gdp, offset);
1724 		offset += sizeof(gdp->bg_checksum); /* skip checksum */
1725 		/* for checksum of struct ext4_group_desc do the rest...*/
1726 		if ((sbi->s_es->s_feature_incompat &
1727 		     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1728 		    offset < le16_to_cpu(sbi->s_es->s_desc_size))
1729 			crc = crc16(crc, (__u8 *)gdp + offset,
1730 				    le16_to_cpu(sbi->s_es->s_desc_size) -
1731 					offset);
1732 	}
1733 
1734 	return cpu_to_le16(crc);
1735 }
1736 
1737 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1738 				struct ext4_group_desc *gdp)
1739 {
1740 	if ((sbi->s_es->s_feature_ro_compat &
1741 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1742 	    (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1743 		return 0;
1744 
1745 	return 1;
1746 }
1747 
1748 /* Called at mount-time, super-block is locked */
1749 static int ext4_check_descriptors(struct super_block *sb)
1750 {
1751 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1752 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1753 	ext4_fsblk_t last_block;
1754 	ext4_fsblk_t block_bitmap;
1755 	ext4_fsblk_t inode_bitmap;
1756 	ext4_fsblk_t inode_table;
1757 	int flexbg_flag = 0;
1758 	ext4_group_t i;
1759 
1760 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1761 		flexbg_flag = 1;
1762 
1763 	ext4_debug("Checking group descriptors");
1764 
1765 	for (i = 0; i < sbi->s_groups_count; i++) {
1766 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1767 
1768 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
1769 			last_block = ext4_blocks_count(sbi->s_es) - 1;
1770 		else
1771 			last_block = first_block +
1772 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
1773 
1774 		block_bitmap = ext4_block_bitmap(sb, gdp);
1775 		if (block_bitmap < first_block || block_bitmap > last_block) {
1776 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1777 			       "Block bitmap for group %u not in group "
1778 			       "(block %llu)!", i, block_bitmap);
1779 			return 0;
1780 		}
1781 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
1782 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
1783 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1784 			       "Inode bitmap for group %u not in group "
1785 			       "(block %llu)!", i, inode_bitmap);
1786 			return 0;
1787 		}
1788 		inode_table = ext4_inode_table(sb, gdp);
1789 		if (inode_table < first_block ||
1790 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
1791 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1792 			       "Inode table for group %u not in group "
1793 			       "(block %llu)!", i, inode_table);
1794 			return 0;
1795 		}
1796 		ext4_lock_group(sb, i);
1797 		if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1798 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1799 				 "Checksum for group %u failed (%u!=%u)",
1800 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1801 				     gdp)), le16_to_cpu(gdp->bg_checksum));
1802 			if (!(sb->s_flags & MS_RDONLY)) {
1803 				ext4_unlock_group(sb, i);
1804 				return 0;
1805 			}
1806 		}
1807 		ext4_unlock_group(sb, i);
1808 		if (!flexbg_flag)
1809 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
1810 	}
1811 
1812 	ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1813 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
1814 	return 1;
1815 }
1816 
1817 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1818  * the superblock) which were deleted from all directories, but held open by
1819  * a process at the time of a crash.  We walk the list and try to delete these
1820  * inodes at recovery time (only with a read-write filesystem).
1821  *
1822  * In order to keep the orphan inode chain consistent during traversal (in
1823  * case of crash during recovery), we link each inode into the superblock
1824  * orphan list_head and handle it the same way as an inode deletion during
1825  * normal operation (which journals the operations for us).
1826  *
1827  * We only do an iget() and an iput() on each inode, which is very safe if we
1828  * accidentally point at an in-use or already deleted inode.  The worst that
1829  * can happen in this case is that we get a "bit already cleared" message from
1830  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1831  * e2fsck was run on this filesystem, and it must have already done the orphan
1832  * inode cleanup for us, so we can safely abort without any further action.
1833  */
1834 static void ext4_orphan_cleanup(struct super_block *sb,
1835 				struct ext4_super_block *es)
1836 {
1837 	unsigned int s_flags = sb->s_flags;
1838 	int nr_orphans = 0, nr_truncates = 0;
1839 #ifdef CONFIG_QUOTA
1840 	int i;
1841 #endif
1842 	if (!es->s_last_orphan) {
1843 		jbd_debug(4, "no orphan inodes to clean up\n");
1844 		return;
1845 	}
1846 
1847 	if (bdev_read_only(sb->s_bdev)) {
1848 		ext4_msg(sb, KERN_ERR, "write access "
1849 			"unavailable, skipping orphan cleanup");
1850 		return;
1851 	}
1852 
1853 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1854 		if (es->s_last_orphan)
1855 			jbd_debug(1, "Errors on filesystem, "
1856 				  "clearing orphan list.\n");
1857 		es->s_last_orphan = 0;
1858 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1859 		return;
1860 	}
1861 
1862 	if (s_flags & MS_RDONLY) {
1863 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
1864 		sb->s_flags &= ~MS_RDONLY;
1865 	}
1866 #ifdef CONFIG_QUOTA
1867 	/* Needed for iput() to work correctly and not trash data */
1868 	sb->s_flags |= MS_ACTIVE;
1869 	/* Turn on quotas so that they are updated correctly */
1870 	for (i = 0; i < MAXQUOTAS; i++) {
1871 		if (EXT4_SB(sb)->s_qf_names[i]) {
1872 			int ret = ext4_quota_on_mount(sb, i);
1873 			if (ret < 0)
1874 				ext4_msg(sb, KERN_ERR,
1875 					"Cannot turn on journaled "
1876 					"quota: error %d", ret);
1877 		}
1878 	}
1879 #endif
1880 
1881 	while (es->s_last_orphan) {
1882 		struct inode *inode;
1883 
1884 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1885 		if (IS_ERR(inode)) {
1886 			es->s_last_orphan = 0;
1887 			break;
1888 		}
1889 
1890 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1891 		vfs_dq_init(inode);
1892 		if (inode->i_nlink) {
1893 			ext4_msg(sb, KERN_DEBUG,
1894 				"%s: truncating inode %lu to %lld bytes",
1895 				__func__, inode->i_ino, inode->i_size);
1896 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
1897 				  inode->i_ino, inode->i_size);
1898 			ext4_truncate(inode);
1899 			nr_truncates++;
1900 		} else {
1901 			ext4_msg(sb, KERN_DEBUG,
1902 				"%s: deleting unreferenced inode %lu",
1903 				__func__, inode->i_ino);
1904 			jbd_debug(2, "deleting unreferenced inode %lu\n",
1905 				  inode->i_ino);
1906 			nr_orphans++;
1907 		}
1908 		iput(inode);  /* The delete magic happens here! */
1909 	}
1910 
1911 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
1912 
1913 	if (nr_orphans)
1914 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
1915 		       PLURAL(nr_orphans));
1916 	if (nr_truncates)
1917 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
1918 		       PLURAL(nr_truncates));
1919 #ifdef CONFIG_QUOTA
1920 	/* Turn quotas off */
1921 	for (i = 0; i < MAXQUOTAS; i++) {
1922 		if (sb_dqopt(sb)->files[i])
1923 			vfs_quota_off(sb, i, 0);
1924 	}
1925 #endif
1926 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1927 }
1928 
1929 /*
1930  * Maximal extent format file size.
1931  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1932  * extent format containers, within a sector_t, and within i_blocks
1933  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1934  * so that won't be a limiting factor.
1935  *
1936  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1937  */
1938 static loff_t ext4_max_size(int blkbits, int has_huge_files)
1939 {
1940 	loff_t res;
1941 	loff_t upper_limit = MAX_LFS_FILESIZE;
1942 
1943 	/* small i_blocks in vfs inode? */
1944 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1945 		/*
1946 		 * CONFIG_LBDAF is not enabled implies the inode
1947 		 * i_block represent total blocks in 512 bytes
1948 		 * 32 == size of vfs inode i_blocks * 8
1949 		 */
1950 		upper_limit = (1LL << 32) - 1;
1951 
1952 		/* total blocks in file system block size */
1953 		upper_limit >>= (blkbits - 9);
1954 		upper_limit <<= blkbits;
1955 	}
1956 
1957 	/* 32-bit extent-start container, ee_block */
1958 	res = 1LL << 32;
1959 	res <<= blkbits;
1960 	res -= 1;
1961 
1962 	/* Sanity check against vm- & vfs- imposed limits */
1963 	if (res > upper_limit)
1964 		res = upper_limit;
1965 
1966 	return res;
1967 }
1968 
1969 /*
1970  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1971  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1972  * We need to be 1 filesystem block less than the 2^48 sector limit.
1973  */
1974 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
1975 {
1976 	loff_t res = EXT4_NDIR_BLOCKS;
1977 	int meta_blocks;
1978 	loff_t upper_limit;
1979 	/* This is calculated to be the largest file size for a dense, block
1980 	 * mapped file such that the file's total number of 512-byte sectors,
1981 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
1982 	 *
1983 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
1984 	 * number of 512-byte sectors of the file.
1985 	 */
1986 
1987 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1988 		/*
1989 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
1990 		 * the inode i_block field represents total file blocks in
1991 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
1992 		 */
1993 		upper_limit = (1LL << 32) - 1;
1994 
1995 		/* total blocks in file system block size */
1996 		upper_limit >>= (bits - 9);
1997 
1998 	} else {
1999 		/*
2000 		 * We use 48 bit ext4_inode i_blocks
2001 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2002 		 * represent total number of blocks in
2003 		 * file system block size
2004 		 */
2005 		upper_limit = (1LL << 48) - 1;
2006 
2007 	}
2008 
2009 	/* indirect blocks */
2010 	meta_blocks = 1;
2011 	/* double indirect blocks */
2012 	meta_blocks += 1 + (1LL << (bits-2));
2013 	/* tripple indirect blocks */
2014 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2015 
2016 	upper_limit -= meta_blocks;
2017 	upper_limit <<= bits;
2018 
2019 	res += 1LL << (bits-2);
2020 	res += 1LL << (2*(bits-2));
2021 	res += 1LL << (3*(bits-2));
2022 	res <<= bits;
2023 	if (res > upper_limit)
2024 		res = upper_limit;
2025 
2026 	if (res > MAX_LFS_FILESIZE)
2027 		res = MAX_LFS_FILESIZE;
2028 
2029 	return res;
2030 }
2031 
2032 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2033 				   ext4_fsblk_t logical_sb_block, int nr)
2034 {
2035 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2036 	ext4_group_t bg, first_meta_bg;
2037 	int has_super = 0;
2038 
2039 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2040 
2041 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2042 	    nr < first_meta_bg)
2043 		return logical_sb_block + nr + 1;
2044 	bg = sbi->s_desc_per_block * nr;
2045 	if (ext4_bg_has_super(sb, bg))
2046 		has_super = 1;
2047 
2048 	return (has_super + ext4_group_first_block_no(sb, bg));
2049 }
2050 
2051 /**
2052  * ext4_get_stripe_size: Get the stripe size.
2053  * @sbi: In memory super block info
2054  *
2055  * If we have specified it via mount option, then
2056  * use the mount option value. If the value specified at mount time is
2057  * greater than the blocks per group use the super block value.
2058  * If the super block value is greater than blocks per group return 0.
2059  * Allocator needs it be less than blocks per group.
2060  *
2061  */
2062 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2063 {
2064 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2065 	unsigned long stripe_width =
2066 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2067 
2068 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2069 		return sbi->s_stripe;
2070 
2071 	if (stripe_width <= sbi->s_blocks_per_group)
2072 		return stripe_width;
2073 
2074 	if (stride <= sbi->s_blocks_per_group)
2075 		return stride;
2076 
2077 	return 0;
2078 }
2079 
2080 /* sysfs supprt */
2081 
2082 struct ext4_attr {
2083 	struct attribute attr;
2084 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2085 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2086 			 const char *, size_t);
2087 	int offset;
2088 };
2089 
2090 static int parse_strtoul(const char *buf,
2091 		unsigned long max, unsigned long *value)
2092 {
2093 	char *endp;
2094 
2095 	while (*buf && isspace(*buf))
2096 		buf++;
2097 	*value = simple_strtoul(buf, &endp, 0);
2098 	while (*endp && isspace(*endp))
2099 		endp++;
2100 	if (*endp || *value > max)
2101 		return -EINVAL;
2102 
2103 	return 0;
2104 }
2105 
2106 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2107 					      struct ext4_sb_info *sbi,
2108 					      char *buf)
2109 {
2110 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2111 			(s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2112 }
2113 
2114 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2115 					 struct ext4_sb_info *sbi, char *buf)
2116 {
2117 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2118 
2119 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2120 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2121 			 sbi->s_sectors_written_start) >> 1);
2122 }
2123 
2124 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2125 					  struct ext4_sb_info *sbi, char *buf)
2126 {
2127 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2128 
2129 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2130 			sbi->s_kbytes_written +
2131 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2132 			  EXT4_SB(sb)->s_sectors_written_start) >> 1));
2133 }
2134 
2135 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2136 					  struct ext4_sb_info *sbi,
2137 					  const char *buf, size_t count)
2138 {
2139 	unsigned long t;
2140 
2141 	if (parse_strtoul(buf, 0x40000000, &t))
2142 		return -EINVAL;
2143 
2144 	if (!is_power_of_2(t))
2145 		return -EINVAL;
2146 
2147 	sbi->s_inode_readahead_blks = t;
2148 	return count;
2149 }
2150 
2151 static ssize_t sbi_ui_show(struct ext4_attr *a,
2152 			   struct ext4_sb_info *sbi, char *buf)
2153 {
2154 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2155 
2156 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2157 }
2158 
2159 static ssize_t sbi_ui_store(struct ext4_attr *a,
2160 			    struct ext4_sb_info *sbi,
2161 			    const char *buf, size_t count)
2162 {
2163 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2164 	unsigned long t;
2165 
2166 	if (parse_strtoul(buf, 0xffffffff, &t))
2167 		return -EINVAL;
2168 	*ui = t;
2169 	return count;
2170 }
2171 
2172 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2173 static struct ext4_attr ext4_attr_##_name = {			\
2174 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2175 	.show	= _show,					\
2176 	.store	= _store,					\
2177 	.offset = offsetof(struct ext4_sb_info, _elname),	\
2178 }
2179 #define EXT4_ATTR(name, mode, show, store) \
2180 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2181 
2182 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2183 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2184 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2185 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2186 #define ATTR_LIST(name) &ext4_attr_##name.attr
2187 
2188 EXT4_RO_ATTR(delayed_allocation_blocks);
2189 EXT4_RO_ATTR(session_write_kbytes);
2190 EXT4_RO_ATTR(lifetime_write_kbytes);
2191 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2192 		 inode_readahead_blks_store, s_inode_readahead_blks);
2193 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2194 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2195 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2196 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2197 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2198 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2199 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2200 
2201 static struct attribute *ext4_attrs[] = {
2202 	ATTR_LIST(delayed_allocation_blocks),
2203 	ATTR_LIST(session_write_kbytes),
2204 	ATTR_LIST(lifetime_write_kbytes),
2205 	ATTR_LIST(inode_readahead_blks),
2206 	ATTR_LIST(inode_goal),
2207 	ATTR_LIST(mb_stats),
2208 	ATTR_LIST(mb_max_to_scan),
2209 	ATTR_LIST(mb_min_to_scan),
2210 	ATTR_LIST(mb_order2_req),
2211 	ATTR_LIST(mb_stream_req),
2212 	ATTR_LIST(mb_group_prealloc),
2213 	NULL,
2214 };
2215 
2216 static ssize_t ext4_attr_show(struct kobject *kobj,
2217 			      struct attribute *attr, char *buf)
2218 {
2219 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2220 						s_kobj);
2221 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2222 
2223 	return a->show ? a->show(a, sbi, buf) : 0;
2224 }
2225 
2226 static ssize_t ext4_attr_store(struct kobject *kobj,
2227 			       struct attribute *attr,
2228 			       const char *buf, size_t len)
2229 {
2230 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2231 						s_kobj);
2232 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2233 
2234 	return a->store ? a->store(a, sbi, buf, len) : 0;
2235 }
2236 
2237 static void ext4_sb_release(struct kobject *kobj)
2238 {
2239 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2240 						s_kobj);
2241 	complete(&sbi->s_kobj_unregister);
2242 }
2243 
2244 
2245 static struct sysfs_ops ext4_attr_ops = {
2246 	.show	= ext4_attr_show,
2247 	.store	= ext4_attr_store,
2248 };
2249 
2250 static struct kobj_type ext4_ktype = {
2251 	.default_attrs	= ext4_attrs,
2252 	.sysfs_ops	= &ext4_attr_ops,
2253 	.release	= ext4_sb_release,
2254 };
2255 
2256 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
2257 				__releases(kernel_lock)
2258 				__acquires(kernel_lock)
2259 {
2260 	struct buffer_head *bh;
2261 	struct ext4_super_block *es = NULL;
2262 	struct ext4_sb_info *sbi;
2263 	ext4_fsblk_t block;
2264 	ext4_fsblk_t sb_block = get_sb_block(&data);
2265 	ext4_fsblk_t logical_sb_block;
2266 	unsigned long offset = 0;
2267 	unsigned long journal_devnum = 0;
2268 	unsigned long def_mount_opts;
2269 	struct inode *root;
2270 	char *cp;
2271 	const char *descr;
2272 	int ret = -EINVAL;
2273 	int blocksize;
2274 	unsigned int db_count;
2275 	unsigned int i;
2276 	int needs_recovery, has_huge_files;
2277 	int features;
2278 	__u64 blocks_count;
2279 	int err;
2280 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2281 
2282 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2283 	if (!sbi)
2284 		return -ENOMEM;
2285 
2286 	sbi->s_blockgroup_lock =
2287 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
2288 	if (!sbi->s_blockgroup_lock) {
2289 		kfree(sbi);
2290 		return -ENOMEM;
2291 	}
2292 	sb->s_fs_info = sbi;
2293 	sbi->s_mount_opt = 0;
2294 	sbi->s_resuid = EXT4_DEF_RESUID;
2295 	sbi->s_resgid = EXT4_DEF_RESGID;
2296 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
2297 	sbi->s_sb_block = sb_block;
2298 	sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part,
2299 						      sectors[1]);
2300 
2301 	unlock_kernel();
2302 
2303 	/* Cleanup superblock name */
2304 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
2305 		*cp = '!';
2306 
2307 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
2308 	if (!blocksize) {
2309 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
2310 		goto out_fail;
2311 	}
2312 
2313 	/*
2314 	 * The ext4 superblock will not be buffer aligned for other than 1kB
2315 	 * block sizes.  We need to calculate the offset from buffer start.
2316 	 */
2317 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
2318 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2319 		offset = do_div(logical_sb_block, blocksize);
2320 	} else {
2321 		logical_sb_block = sb_block;
2322 	}
2323 
2324 	if (!(bh = sb_bread(sb, logical_sb_block))) {
2325 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
2326 		goto out_fail;
2327 	}
2328 	/*
2329 	 * Note: s_es must be initialized as soon as possible because
2330 	 *       some ext4 macro-instructions depend on its value
2331 	 */
2332 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2333 	sbi->s_es = es;
2334 	sb->s_magic = le16_to_cpu(es->s_magic);
2335 	if (sb->s_magic != EXT4_SUPER_MAGIC)
2336 		goto cantfind_ext4;
2337 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
2338 
2339 	/* Set defaults before we parse the mount options */
2340 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
2341 	if (def_mount_opts & EXT4_DEFM_DEBUG)
2342 		set_opt(sbi->s_mount_opt, DEBUG);
2343 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
2344 		set_opt(sbi->s_mount_opt, GRPID);
2345 	if (def_mount_opts & EXT4_DEFM_UID16)
2346 		set_opt(sbi->s_mount_opt, NO_UID32);
2347 #ifdef CONFIG_EXT4_FS_XATTR
2348 	if (def_mount_opts & EXT4_DEFM_XATTR_USER)
2349 		set_opt(sbi->s_mount_opt, XATTR_USER);
2350 #endif
2351 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2352 	if (def_mount_opts & EXT4_DEFM_ACL)
2353 		set_opt(sbi->s_mount_opt, POSIX_ACL);
2354 #endif
2355 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
2356 		sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
2357 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
2358 		sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
2359 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
2360 		sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
2361 
2362 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
2363 		set_opt(sbi->s_mount_opt, ERRORS_PANIC);
2364 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
2365 		set_opt(sbi->s_mount_opt, ERRORS_CONT);
2366 	else
2367 		set_opt(sbi->s_mount_opt, ERRORS_RO);
2368 
2369 	sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
2370 	sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
2371 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
2372 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
2373 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
2374 	sbi->s_mb_history_max = default_mb_history_length;
2375 
2376 	set_opt(sbi->s_mount_opt, BARRIER);
2377 
2378 	/*
2379 	 * enable delayed allocation by default
2380 	 * Use -o nodelalloc to turn it off
2381 	 */
2382 	set_opt(sbi->s_mount_opt, DELALLOC);
2383 
2384 	if (!parse_options((char *) data, sb, &journal_devnum,
2385 			   &journal_ioprio, NULL, 0))
2386 		goto failed_mount;
2387 
2388 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2389 		((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2390 
2391 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
2392 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
2393 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
2394 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
2395 		ext4_msg(sb, KERN_WARNING,
2396 		       "feature flags set on rev 0 fs, "
2397 		       "running e2fsck is recommended");
2398 
2399 	/*
2400 	 * Check feature flags regardless of the revision level, since we
2401 	 * previously didn't change the revision level when setting the flags,
2402 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
2403 	 */
2404 	features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP);
2405 	if (features) {
2406 		ext4_msg(sb, KERN_ERR,
2407 			"Couldn't mount because of "
2408 			"unsupported optional features (%x)",
2409 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2410 			~EXT4_FEATURE_INCOMPAT_SUPP));
2411 		goto failed_mount;
2412 	}
2413 	features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP);
2414 	if (!(sb->s_flags & MS_RDONLY) && features) {
2415 		ext4_msg(sb, KERN_ERR,
2416 			"Couldn't mount RDWR because of "
2417 			"unsupported optional features (%x)",
2418 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2419 			~EXT4_FEATURE_RO_COMPAT_SUPP));
2420 		goto failed_mount;
2421 	}
2422 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2423 				    EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
2424 	if (has_huge_files) {
2425 		/*
2426 		 * Large file size enabled file system can only be
2427 		 * mount if kernel is build with CONFIG_LBDAF
2428 		 */
2429 		if (sizeof(root->i_blocks) < sizeof(u64) &&
2430 				!(sb->s_flags & MS_RDONLY)) {
2431 			ext4_msg(sb, KERN_ERR, "Filesystem with huge "
2432 					"files cannot be mounted read-write "
2433 					"without CONFIG_LBDAF");
2434 			goto failed_mount;
2435 		}
2436 	}
2437 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2438 
2439 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2440 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
2441 		ext4_msg(sb, KERN_ERR,
2442 		       "Unsupported filesystem blocksize %d", blocksize);
2443 		goto failed_mount;
2444 	}
2445 
2446 	if (sb->s_blocksize != blocksize) {
2447 		/* Validate the filesystem blocksize */
2448 		if (!sb_set_blocksize(sb, blocksize)) {
2449 			ext4_msg(sb, KERN_ERR, "bad block size %d",
2450 					blocksize);
2451 			goto failed_mount;
2452 		}
2453 
2454 		brelse(bh);
2455 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2456 		offset = do_div(logical_sb_block, blocksize);
2457 		bh = sb_bread(sb, logical_sb_block);
2458 		if (!bh) {
2459 			ext4_msg(sb, KERN_ERR,
2460 			       "Can't read superblock on 2nd try");
2461 			goto failed_mount;
2462 		}
2463 		es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2464 		sbi->s_es = es;
2465 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2466 			ext4_msg(sb, KERN_ERR,
2467 			       "Magic mismatch, very weird!");
2468 			goto failed_mount;
2469 		}
2470 	}
2471 
2472 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
2473 						      has_huge_files);
2474 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
2475 
2476 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2477 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2478 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2479 	} else {
2480 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2481 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2482 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2483 		    (!is_power_of_2(sbi->s_inode_size)) ||
2484 		    (sbi->s_inode_size > blocksize)) {
2485 			ext4_msg(sb, KERN_ERR,
2486 			       "unsupported inode size: %d",
2487 			       sbi->s_inode_size);
2488 			goto failed_mount;
2489 		}
2490 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2491 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2492 	}
2493 
2494 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2495 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2496 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2497 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2498 		    !is_power_of_2(sbi->s_desc_size)) {
2499 			ext4_msg(sb, KERN_ERR,
2500 			       "unsupported descriptor size %lu",
2501 			       sbi->s_desc_size);
2502 			goto failed_mount;
2503 		}
2504 	} else
2505 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2506 
2507 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2508 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2509 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2510 		goto cantfind_ext4;
2511 
2512 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2513 	if (sbi->s_inodes_per_block == 0)
2514 		goto cantfind_ext4;
2515 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
2516 					sbi->s_inodes_per_block;
2517 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2518 	sbi->s_sbh = bh;
2519 	sbi->s_mount_state = le16_to_cpu(es->s_state);
2520 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2521 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2522 
2523 	for (i = 0; i < 4; i++)
2524 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2525 	sbi->s_def_hash_version = es->s_def_hash_version;
2526 	i = le32_to_cpu(es->s_flags);
2527 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
2528 		sbi->s_hash_unsigned = 3;
2529 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
2530 #ifdef __CHAR_UNSIGNED__
2531 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
2532 		sbi->s_hash_unsigned = 3;
2533 #else
2534 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
2535 #endif
2536 		sb->s_dirt = 1;
2537 	}
2538 
2539 	if (sbi->s_blocks_per_group > blocksize * 8) {
2540 		ext4_msg(sb, KERN_ERR,
2541 		       "#blocks per group too big: %lu",
2542 		       sbi->s_blocks_per_group);
2543 		goto failed_mount;
2544 	}
2545 	if (sbi->s_inodes_per_group > blocksize * 8) {
2546 		ext4_msg(sb, KERN_ERR,
2547 		       "#inodes per group too big: %lu",
2548 		       sbi->s_inodes_per_group);
2549 		goto failed_mount;
2550 	}
2551 
2552 	if (ext4_blocks_count(es) >
2553 		    (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
2554 		ext4_msg(sb, KERN_ERR, "filesystem"
2555 			" too large to mount safely");
2556 		if (sizeof(sector_t) < 8)
2557 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
2558 		goto failed_mount;
2559 	}
2560 
2561 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2562 		goto cantfind_ext4;
2563 
2564 	/* check blocks count against device size */
2565 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
2566 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
2567 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
2568 		       "exceeds size of device (%llu blocks)",
2569 		       ext4_blocks_count(es), blocks_count);
2570 		goto failed_mount;
2571 	}
2572 
2573 	/*
2574 	 * It makes no sense for the first data block to be beyond the end
2575 	 * of the filesystem.
2576 	 */
2577 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
2578                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
2579 			 "block %u is beyond end of filesystem (%llu)",
2580 			 le32_to_cpu(es->s_first_data_block),
2581 			 ext4_blocks_count(es));
2582 		goto failed_mount;
2583 	}
2584 	blocks_count = (ext4_blocks_count(es) -
2585 			le32_to_cpu(es->s_first_data_block) +
2586 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
2587 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2588 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
2589 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
2590 		       "(block count %llu, first data block %u, "
2591 		       "blocks per group %lu)", sbi->s_groups_count,
2592 		       ext4_blocks_count(es),
2593 		       le32_to_cpu(es->s_first_data_block),
2594 		       EXT4_BLOCKS_PER_GROUP(sb));
2595 		goto failed_mount;
2596 	}
2597 	sbi->s_groups_count = blocks_count;
2598 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2599 		   EXT4_DESC_PER_BLOCK(sb);
2600 	sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2601 				    GFP_KERNEL);
2602 	if (sbi->s_group_desc == NULL) {
2603 		ext4_msg(sb, KERN_ERR, "not enough memory");
2604 		goto failed_mount;
2605 	}
2606 
2607 #ifdef CONFIG_PROC_FS
2608 	if (ext4_proc_root)
2609 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
2610 #endif
2611 
2612 	bgl_lock_init(sbi->s_blockgroup_lock);
2613 
2614 	for (i = 0; i < db_count; i++) {
2615 		block = descriptor_loc(sb, logical_sb_block, i);
2616 		sbi->s_group_desc[i] = sb_bread(sb, block);
2617 		if (!sbi->s_group_desc[i]) {
2618 			ext4_msg(sb, KERN_ERR,
2619 			       "can't read group descriptor %d", i);
2620 			db_count = i;
2621 			goto failed_mount2;
2622 		}
2623 	}
2624 	if (!ext4_check_descriptors(sb)) {
2625 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
2626 		goto failed_mount2;
2627 	}
2628 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2629 		if (!ext4_fill_flex_info(sb)) {
2630 			ext4_msg(sb, KERN_ERR,
2631 			       "unable to initialize "
2632 			       "flex_bg meta info!");
2633 			goto failed_mount2;
2634 		}
2635 
2636 	sbi->s_gdb_count = db_count;
2637 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2638 	spin_lock_init(&sbi->s_next_gen_lock);
2639 
2640 	err = percpu_counter_init(&sbi->s_freeblocks_counter,
2641 			ext4_count_free_blocks(sb));
2642 	if (!err) {
2643 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
2644 				ext4_count_free_inodes(sb));
2645 	}
2646 	if (!err) {
2647 		err = percpu_counter_init(&sbi->s_dirs_counter,
2648 				ext4_count_dirs(sb));
2649 	}
2650 	if (!err) {
2651 		err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
2652 	}
2653 	if (err) {
2654 		ext4_msg(sb, KERN_ERR, "insufficient memory");
2655 		goto failed_mount3;
2656 	}
2657 
2658 	sbi->s_stripe = ext4_get_stripe_size(sbi);
2659 
2660 	/*
2661 	 * set up enough so that it can read an inode
2662 	 */
2663 	if (!test_opt(sb, NOLOAD) &&
2664 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
2665 		sb->s_op = &ext4_sops;
2666 	else
2667 		sb->s_op = &ext4_nojournal_sops;
2668 	sb->s_export_op = &ext4_export_ops;
2669 	sb->s_xattr = ext4_xattr_handlers;
2670 #ifdef CONFIG_QUOTA
2671 	sb->s_qcop = &ext4_qctl_operations;
2672 	sb->dq_op = &ext4_quota_operations;
2673 #endif
2674 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2675 	mutex_init(&sbi->s_orphan_lock);
2676 	mutex_init(&sbi->s_resize_lock);
2677 
2678 	sb->s_root = NULL;
2679 
2680 	needs_recovery = (es->s_last_orphan != 0 ||
2681 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
2682 				    EXT4_FEATURE_INCOMPAT_RECOVER));
2683 
2684 	/*
2685 	 * The first inode we look at is the journal inode.  Don't try
2686 	 * root first: it may be modified in the journal!
2687 	 */
2688 	if (!test_opt(sb, NOLOAD) &&
2689 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2690 		if (ext4_load_journal(sb, es, journal_devnum))
2691 			goto failed_mount3;
2692 		if (!(sb->s_flags & MS_RDONLY) &&
2693 		    EXT4_SB(sb)->s_journal->j_failed_commit) {
2694 			ext4_msg(sb, KERN_CRIT, "error: "
2695 			       "ext4_fill_super: Journal transaction "
2696 			       "%u is corrupt",
2697 			       EXT4_SB(sb)->s_journal->j_failed_commit);
2698 			if (test_opt(sb, ERRORS_RO)) {
2699 				ext4_msg(sb, KERN_CRIT,
2700 				       "Mounting filesystem read-only");
2701 				sb->s_flags |= MS_RDONLY;
2702 				EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2703 				es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2704 			}
2705 			if (test_opt(sb, ERRORS_PANIC)) {
2706 				EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2707 				es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2708 				ext4_commit_super(sb, 1);
2709 				goto failed_mount4;
2710 			}
2711 		}
2712 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
2713 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2714 		ext4_msg(sb, KERN_ERR, "required journal recovery "
2715 		       "suppressed and not mounted read-only");
2716 		goto failed_mount4;
2717 	} else {
2718 		clear_opt(sbi->s_mount_opt, DATA_FLAGS);
2719 		set_opt(sbi->s_mount_opt, WRITEBACK_DATA);
2720 		sbi->s_journal = NULL;
2721 		needs_recovery = 0;
2722 		goto no_journal;
2723 	}
2724 
2725 	if (ext4_blocks_count(es) > 0xffffffffULL &&
2726 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2727 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
2728 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
2729 		goto failed_mount4;
2730 	}
2731 
2732 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2733 		jbd2_journal_set_features(sbi->s_journal,
2734 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2735 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2736 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2737 		jbd2_journal_set_features(sbi->s_journal,
2738 				JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2739 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2740 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2741 	} else {
2742 		jbd2_journal_clear_features(sbi->s_journal,
2743 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2744 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2745 	}
2746 
2747 	/* We have now updated the journal if required, so we can
2748 	 * validate the data journaling mode. */
2749 	switch (test_opt(sb, DATA_FLAGS)) {
2750 	case 0:
2751 		/* No mode set, assume a default based on the journal
2752 		 * capabilities: ORDERED_DATA if the journal can
2753 		 * cope, else JOURNAL_DATA
2754 		 */
2755 		if (jbd2_journal_check_available_features
2756 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2757 			set_opt(sbi->s_mount_opt, ORDERED_DATA);
2758 		else
2759 			set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2760 		break;
2761 
2762 	case EXT4_MOUNT_ORDERED_DATA:
2763 	case EXT4_MOUNT_WRITEBACK_DATA:
2764 		if (!jbd2_journal_check_available_features
2765 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2766 			ext4_msg(sb, KERN_ERR, "Journal does not support "
2767 			       "requested data journaling mode");
2768 			goto failed_mount4;
2769 		}
2770 	default:
2771 		break;
2772 	}
2773 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
2774 
2775 no_journal:
2776 
2777 	if (test_opt(sb, NOBH)) {
2778 		if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2779 			ext4_msg(sb, KERN_WARNING, "Ignoring nobh option - "
2780 				"its supported only with writeback mode");
2781 			clear_opt(sbi->s_mount_opt, NOBH);
2782 		}
2783 	}
2784 	/*
2785 	 * The jbd2_journal_load will have done any necessary log recovery,
2786 	 * so we can safely mount the rest of the filesystem now.
2787 	 */
2788 
2789 	root = ext4_iget(sb, EXT4_ROOT_INO);
2790 	if (IS_ERR(root)) {
2791 		ext4_msg(sb, KERN_ERR, "get root inode failed");
2792 		ret = PTR_ERR(root);
2793 		goto failed_mount4;
2794 	}
2795 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2796 		iput(root);
2797 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
2798 		goto failed_mount4;
2799 	}
2800 	sb->s_root = d_alloc_root(root);
2801 	if (!sb->s_root) {
2802 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
2803 		iput(root);
2804 		ret = -ENOMEM;
2805 		goto failed_mount4;
2806 	}
2807 
2808 	ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
2809 
2810 	/* determine the minimum size of new large inodes, if present */
2811 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2812 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2813 						     EXT4_GOOD_OLD_INODE_SIZE;
2814 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2815 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2816 			if (sbi->s_want_extra_isize <
2817 			    le16_to_cpu(es->s_want_extra_isize))
2818 				sbi->s_want_extra_isize =
2819 					le16_to_cpu(es->s_want_extra_isize);
2820 			if (sbi->s_want_extra_isize <
2821 			    le16_to_cpu(es->s_min_extra_isize))
2822 				sbi->s_want_extra_isize =
2823 					le16_to_cpu(es->s_min_extra_isize);
2824 		}
2825 	}
2826 	/* Check if enough inode space is available */
2827 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2828 							sbi->s_inode_size) {
2829 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2830 						       EXT4_GOOD_OLD_INODE_SIZE;
2831 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
2832 			 "available");
2833 	}
2834 
2835 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
2836 		ext4_msg(sb, KERN_WARNING, "Ignoring delalloc option - "
2837 			 "requested data journaling mode");
2838 		clear_opt(sbi->s_mount_opt, DELALLOC);
2839 	} else if (test_opt(sb, DELALLOC))
2840 		ext4_msg(sb, KERN_INFO, "delayed allocation enabled");
2841 
2842 	err = ext4_setup_system_zone(sb);
2843 	if (err) {
2844 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
2845 			 "zone (%d)\n", err);
2846 		goto failed_mount4;
2847 	}
2848 
2849 	ext4_ext_init(sb);
2850 	err = ext4_mb_init(sb, needs_recovery);
2851 	if (err) {
2852 		ext4_msg(sb, KERN_ERR, "failed to initalize mballoc (%d)",
2853 			 err);
2854 		goto failed_mount4;
2855 	}
2856 
2857 	sbi->s_kobj.kset = ext4_kset;
2858 	init_completion(&sbi->s_kobj_unregister);
2859 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
2860 				   "%s", sb->s_id);
2861 	if (err) {
2862 		ext4_mb_release(sb);
2863 		ext4_ext_release(sb);
2864 		goto failed_mount4;
2865 	};
2866 
2867 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2868 	ext4_orphan_cleanup(sb, es);
2869 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2870 	if (needs_recovery) {
2871 		ext4_msg(sb, KERN_INFO, "recovery complete");
2872 		ext4_mark_recovery_complete(sb, es);
2873 	}
2874 	if (EXT4_SB(sb)->s_journal) {
2875 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2876 			descr = " journalled data mode";
2877 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2878 			descr = " ordered data mode";
2879 		else
2880 			descr = " writeback data mode";
2881 	} else
2882 		descr = "out journal";
2883 
2884 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s", descr);
2885 
2886 	lock_kernel();
2887 	return 0;
2888 
2889 cantfind_ext4:
2890 	if (!silent)
2891 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
2892 	goto failed_mount;
2893 
2894 failed_mount4:
2895 	ext4_msg(sb, KERN_ERR, "mount failed");
2896 	ext4_release_system_zone(sb);
2897 	if (sbi->s_journal) {
2898 		jbd2_journal_destroy(sbi->s_journal);
2899 		sbi->s_journal = NULL;
2900 	}
2901 failed_mount3:
2902 	if (sbi->s_flex_groups) {
2903 		if (is_vmalloc_addr(sbi->s_flex_groups))
2904 			vfree(sbi->s_flex_groups);
2905 		else
2906 			kfree(sbi->s_flex_groups);
2907 	}
2908 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
2909 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
2910 	percpu_counter_destroy(&sbi->s_dirs_counter);
2911 	percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
2912 failed_mount2:
2913 	for (i = 0; i < db_count; i++)
2914 		brelse(sbi->s_group_desc[i]);
2915 	kfree(sbi->s_group_desc);
2916 failed_mount:
2917 	if (sbi->s_proc) {
2918 		remove_proc_entry(sb->s_id, ext4_proc_root);
2919 	}
2920 #ifdef CONFIG_QUOTA
2921 	for (i = 0; i < MAXQUOTAS; i++)
2922 		kfree(sbi->s_qf_names[i]);
2923 #endif
2924 	ext4_blkdev_remove(sbi);
2925 	brelse(bh);
2926 out_fail:
2927 	sb->s_fs_info = NULL;
2928 	kfree(sbi->s_blockgroup_lock);
2929 	kfree(sbi);
2930 	lock_kernel();
2931 	return ret;
2932 }
2933 
2934 /*
2935  * Setup any per-fs journal parameters now.  We'll do this both on
2936  * initial mount, once the journal has been initialised but before we've
2937  * done any recovery; and again on any subsequent remount.
2938  */
2939 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2940 {
2941 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2942 
2943 	journal->j_commit_interval = sbi->s_commit_interval;
2944 	journal->j_min_batch_time = sbi->s_min_batch_time;
2945 	journal->j_max_batch_time = sbi->s_max_batch_time;
2946 
2947 	spin_lock(&journal->j_state_lock);
2948 	if (test_opt(sb, BARRIER))
2949 		journal->j_flags |= JBD2_BARRIER;
2950 	else
2951 		journal->j_flags &= ~JBD2_BARRIER;
2952 	if (test_opt(sb, DATA_ERR_ABORT))
2953 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
2954 	else
2955 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
2956 	spin_unlock(&journal->j_state_lock);
2957 }
2958 
2959 static journal_t *ext4_get_journal(struct super_block *sb,
2960 				   unsigned int journal_inum)
2961 {
2962 	struct inode *journal_inode;
2963 	journal_t *journal;
2964 
2965 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2966 
2967 	/* First, test for the existence of a valid inode on disk.  Bad
2968 	 * things happen if we iget() an unused inode, as the subsequent
2969 	 * iput() will try to delete it. */
2970 
2971 	journal_inode = ext4_iget(sb, journal_inum);
2972 	if (IS_ERR(journal_inode)) {
2973 		ext4_msg(sb, KERN_ERR, "no journal found");
2974 		return NULL;
2975 	}
2976 	if (!journal_inode->i_nlink) {
2977 		make_bad_inode(journal_inode);
2978 		iput(journal_inode);
2979 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
2980 		return NULL;
2981 	}
2982 
2983 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
2984 		  journal_inode, journal_inode->i_size);
2985 	if (!S_ISREG(journal_inode->i_mode)) {
2986 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
2987 		iput(journal_inode);
2988 		return NULL;
2989 	}
2990 
2991 	journal = jbd2_journal_init_inode(journal_inode);
2992 	if (!journal) {
2993 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
2994 		iput(journal_inode);
2995 		return NULL;
2996 	}
2997 	journal->j_private = sb;
2998 	ext4_init_journal_params(sb, journal);
2999 	return journal;
3000 }
3001 
3002 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3003 				       dev_t j_dev)
3004 {
3005 	struct buffer_head *bh;
3006 	journal_t *journal;
3007 	ext4_fsblk_t start;
3008 	ext4_fsblk_t len;
3009 	int hblock, blocksize;
3010 	ext4_fsblk_t sb_block;
3011 	unsigned long offset;
3012 	struct ext4_super_block *es;
3013 	struct block_device *bdev;
3014 
3015 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3016 
3017 	bdev = ext4_blkdev_get(j_dev, sb);
3018 	if (bdev == NULL)
3019 		return NULL;
3020 
3021 	if (bd_claim(bdev, sb)) {
3022 		ext4_msg(sb, KERN_ERR,
3023 			"failed to claim external journal device");
3024 		blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
3025 		return NULL;
3026 	}
3027 
3028 	blocksize = sb->s_blocksize;
3029 	hblock = bdev_logical_block_size(bdev);
3030 	if (blocksize < hblock) {
3031 		ext4_msg(sb, KERN_ERR,
3032 			"blocksize too small for journal device");
3033 		goto out_bdev;
3034 	}
3035 
3036 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3037 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3038 	set_blocksize(bdev, blocksize);
3039 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
3040 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3041 		       "external journal");
3042 		goto out_bdev;
3043 	}
3044 
3045 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3046 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3047 	    !(le32_to_cpu(es->s_feature_incompat) &
3048 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3049 		ext4_msg(sb, KERN_ERR, "external journal has "
3050 					"bad superblock");
3051 		brelse(bh);
3052 		goto out_bdev;
3053 	}
3054 
3055 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3056 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3057 		brelse(bh);
3058 		goto out_bdev;
3059 	}
3060 
3061 	len = ext4_blocks_count(es);
3062 	start = sb_block + 1;
3063 	brelse(bh);	/* we're done with the superblock */
3064 
3065 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3066 					start, len, blocksize);
3067 	if (!journal) {
3068 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
3069 		goto out_bdev;
3070 	}
3071 	journal->j_private = sb;
3072 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
3073 	wait_on_buffer(journal->j_sb_buffer);
3074 	if (!buffer_uptodate(journal->j_sb_buffer)) {
3075 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3076 		goto out_journal;
3077 	}
3078 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3079 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
3080 					"user (unsupported) - %d",
3081 			be32_to_cpu(journal->j_superblock->s_nr_users));
3082 		goto out_journal;
3083 	}
3084 	EXT4_SB(sb)->journal_bdev = bdev;
3085 	ext4_init_journal_params(sb, journal);
3086 	return journal;
3087 
3088 out_journal:
3089 	jbd2_journal_destroy(journal);
3090 out_bdev:
3091 	ext4_blkdev_put(bdev);
3092 	return NULL;
3093 }
3094 
3095 static int ext4_load_journal(struct super_block *sb,
3096 			     struct ext4_super_block *es,
3097 			     unsigned long journal_devnum)
3098 {
3099 	journal_t *journal;
3100 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3101 	dev_t journal_dev;
3102 	int err = 0;
3103 	int really_read_only;
3104 
3105 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3106 
3107 	if (journal_devnum &&
3108 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3109 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3110 			"numbers have changed");
3111 		journal_dev = new_decode_dev(journal_devnum);
3112 	} else
3113 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3114 
3115 	really_read_only = bdev_read_only(sb->s_bdev);
3116 
3117 	/*
3118 	 * Are we loading a blank journal or performing recovery after a
3119 	 * crash?  For recovery, we need to check in advance whether we
3120 	 * can get read-write access to the device.
3121 	 */
3122 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3123 		if (sb->s_flags & MS_RDONLY) {
3124 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
3125 					"required on readonly filesystem");
3126 			if (really_read_only) {
3127 				ext4_msg(sb, KERN_ERR, "write access "
3128 					"unavailable, cannot proceed");
3129 				return -EROFS;
3130 			}
3131 			ext4_msg(sb, KERN_INFO, "write access will "
3132 			       "be enabled during recovery");
3133 		}
3134 	}
3135 
3136 	if (journal_inum && journal_dev) {
3137 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3138 		       "and inode journals!");
3139 		return -EINVAL;
3140 	}
3141 
3142 	if (journal_inum) {
3143 		if (!(journal = ext4_get_journal(sb, journal_inum)))
3144 			return -EINVAL;
3145 	} else {
3146 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3147 			return -EINVAL;
3148 	}
3149 
3150 	if (journal->j_flags & JBD2_BARRIER)
3151 		ext4_msg(sb, KERN_INFO, "barriers enabled");
3152 	else
3153 		ext4_msg(sb, KERN_INFO, "barriers disabled");
3154 
3155 	if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
3156 		err = jbd2_journal_update_format(journal);
3157 		if (err)  {
3158 			ext4_msg(sb, KERN_ERR, "error updating journal");
3159 			jbd2_journal_destroy(journal);
3160 			return err;
3161 		}
3162 	}
3163 
3164 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3165 		err = jbd2_journal_wipe(journal, !really_read_only);
3166 	if (!err)
3167 		err = jbd2_journal_load(journal);
3168 
3169 	if (err) {
3170 		ext4_msg(sb, KERN_ERR, "error loading journal");
3171 		jbd2_journal_destroy(journal);
3172 		return err;
3173 	}
3174 
3175 	EXT4_SB(sb)->s_journal = journal;
3176 	ext4_clear_journal_err(sb, es);
3177 
3178 	if (journal_devnum &&
3179 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3180 		es->s_journal_dev = cpu_to_le32(journal_devnum);
3181 
3182 		/* Make sure we flush the recovery flag to disk. */
3183 		ext4_commit_super(sb, 1);
3184 	}
3185 
3186 	return 0;
3187 }
3188 
3189 static int ext4_commit_super(struct super_block *sb, int sync)
3190 {
3191 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
3192 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3193 	int error = 0;
3194 
3195 	if (!sbh)
3196 		return error;
3197 	if (buffer_write_io_error(sbh)) {
3198 		/*
3199 		 * Oh, dear.  A previous attempt to write the
3200 		 * superblock failed.  This could happen because the
3201 		 * USB device was yanked out.  Or it could happen to
3202 		 * be a transient write error and maybe the block will
3203 		 * be remapped.  Nothing we can do but to retry the
3204 		 * write and hope for the best.
3205 		 */
3206 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
3207 		       "superblock detected");
3208 		clear_buffer_write_io_error(sbh);
3209 		set_buffer_uptodate(sbh);
3210 	}
3211 	es->s_wtime = cpu_to_le32(get_seconds());
3212 	es->s_kbytes_written =
3213 		cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
3214 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
3215 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
3216 	ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
3217 					&EXT4_SB(sb)->s_freeblocks_counter));
3218 	es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(
3219 					&EXT4_SB(sb)->s_freeinodes_counter));
3220 	sb->s_dirt = 0;
3221 	BUFFER_TRACE(sbh, "marking dirty");
3222 	mark_buffer_dirty(sbh);
3223 	if (sync) {
3224 		error = sync_dirty_buffer(sbh);
3225 		if (error)
3226 			return error;
3227 
3228 		error = buffer_write_io_error(sbh);
3229 		if (error) {
3230 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
3231 			       "superblock");
3232 			clear_buffer_write_io_error(sbh);
3233 			set_buffer_uptodate(sbh);
3234 		}
3235 	}
3236 	return error;
3237 }
3238 
3239 /*
3240  * Have we just finished recovery?  If so, and if we are mounting (or
3241  * remounting) the filesystem readonly, then we will end up with a
3242  * consistent fs on disk.  Record that fact.
3243  */
3244 static void ext4_mark_recovery_complete(struct super_block *sb,
3245 					struct ext4_super_block *es)
3246 {
3247 	journal_t *journal = EXT4_SB(sb)->s_journal;
3248 
3249 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3250 		BUG_ON(journal != NULL);
3251 		return;
3252 	}
3253 	jbd2_journal_lock_updates(journal);
3254 	if (jbd2_journal_flush(journal) < 0)
3255 		goto out;
3256 
3257 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
3258 	    sb->s_flags & MS_RDONLY) {
3259 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3260 		ext4_commit_super(sb, 1);
3261 	}
3262 
3263 out:
3264 	jbd2_journal_unlock_updates(journal);
3265 }
3266 
3267 /*
3268  * If we are mounting (or read-write remounting) a filesystem whose journal
3269  * has recorded an error from a previous lifetime, move that error to the
3270  * main filesystem now.
3271  */
3272 static void ext4_clear_journal_err(struct super_block *sb,
3273 				   struct ext4_super_block *es)
3274 {
3275 	journal_t *journal;
3276 	int j_errno;
3277 	const char *errstr;
3278 
3279 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3280 
3281 	journal = EXT4_SB(sb)->s_journal;
3282 
3283 	/*
3284 	 * Now check for any error status which may have been recorded in the
3285 	 * journal by a prior ext4_error() or ext4_abort()
3286 	 */
3287 
3288 	j_errno = jbd2_journal_errno(journal);
3289 	if (j_errno) {
3290 		char nbuf[16];
3291 
3292 		errstr = ext4_decode_error(sb, j_errno, nbuf);
3293 		ext4_warning(sb, __func__, "Filesystem error recorded "
3294 			     "from previous mount: %s", errstr);
3295 		ext4_warning(sb, __func__, "Marking fs in need of "
3296 			     "filesystem check.");
3297 
3298 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
3299 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
3300 		ext4_commit_super(sb, 1);
3301 
3302 		jbd2_journal_clear_err(journal);
3303 	}
3304 }
3305 
3306 /*
3307  * Force the running and committing transactions to commit,
3308  * and wait on the commit.
3309  */
3310 int ext4_force_commit(struct super_block *sb)
3311 {
3312 	journal_t *journal;
3313 	int ret = 0;
3314 
3315 	if (sb->s_flags & MS_RDONLY)
3316 		return 0;
3317 
3318 	journal = EXT4_SB(sb)->s_journal;
3319 	if (journal)
3320 		ret = ext4_journal_force_commit(journal);
3321 
3322 	return ret;
3323 }
3324 
3325 static void ext4_write_super(struct super_block *sb)
3326 {
3327 	lock_super(sb);
3328 	ext4_commit_super(sb, 1);
3329 	unlock_super(sb);
3330 }
3331 
3332 static int ext4_sync_fs(struct super_block *sb, int wait)
3333 {
3334 	int ret = 0;
3335 	tid_t target;
3336 
3337 	trace_ext4_sync_fs(sb, wait);
3338 	if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
3339 		if (wait)
3340 			jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
3341 	}
3342 	return ret;
3343 }
3344 
3345 /*
3346  * LVM calls this function before a (read-only) snapshot is created.  This
3347  * gives us a chance to flush the journal completely and mark the fs clean.
3348  */
3349 static int ext4_freeze(struct super_block *sb)
3350 {
3351 	int error = 0;
3352 	journal_t *journal;
3353 
3354 	if (sb->s_flags & MS_RDONLY)
3355 		return 0;
3356 
3357 	journal = EXT4_SB(sb)->s_journal;
3358 
3359 	/* Now we set up the journal barrier. */
3360 	jbd2_journal_lock_updates(journal);
3361 
3362 	/*
3363 	 * Don't clear the needs_recovery flag if we failed to flush
3364 	 * the journal.
3365 	 */
3366 	error = jbd2_journal_flush(journal);
3367 	if (error < 0) {
3368 	out:
3369 		jbd2_journal_unlock_updates(journal);
3370 		return error;
3371 	}
3372 
3373 	/* Journal blocked and flushed, clear needs_recovery flag. */
3374 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3375 	error = ext4_commit_super(sb, 1);
3376 	if (error)
3377 		goto out;
3378 	return 0;
3379 }
3380 
3381 /*
3382  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
3383  * flag here, even though the filesystem is not technically dirty yet.
3384  */
3385 static int ext4_unfreeze(struct super_block *sb)
3386 {
3387 	if (sb->s_flags & MS_RDONLY)
3388 		return 0;
3389 
3390 	lock_super(sb);
3391 	/* Reset the needs_recovery flag before the fs is unlocked. */
3392 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3393 	ext4_commit_super(sb, 1);
3394 	unlock_super(sb);
3395 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3396 	return 0;
3397 }
3398 
3399 static int ext4_remount(struct super_block *sb, int *flags, char *data)
3400 {
3401 	struct ext4_super_block *es;
3402 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3403 	ext4_fsblk_t n_blocks_count = 0;
3404 	unsigned long old_sb_flags;
3405 	struct ext4_mount_options old_opts;
3406 	ext4_group_t g;
3407 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3408 	int err;
3409 #ifdef CONFIG_QUOTA
3410 	int i;
3411 #endif
3412 
3413 	lock_kernel();
3414 
3415 	/* Store the original options */
3416 	lock_super(sb);
3417 	old_sb_flags = sb->s_flags;
3418 	old_opts.s_mount_opt = sbi->s_mount_opt;
3419 	old_opts.s_resuid = sbi->s_resuid;
3420 	old_opts.s_resgid = sbi->s_resgid;
3421 	old_opts.s_commit_interval = sbi->s_commit_interval;
3422 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
3423 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
3424 #ifdef CONFIG_QUOTA
3425 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
3426 	for (i = 0; i < MAXQUOTAS; i++)
3427 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
3428 #endif
3429 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
3430 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
3431 
3432 	/*
3433 	 * Allow the "check" option to be passed as a remount option.
3434 	 */
3435 	if (!parse_options(data, sb, NULL, &journal_ioprio,
3436 			   &n_blocks_count, 1)) {
3437 		err = -EINVAL;
3438 		goto restore_opts;
3439 	}
3440 
3441 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
3442 		ext4_abort(sb, __func__, "Abort forced by user");
3443 
3444 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3445 		((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
3446 
3447 	es = sbi->s_es;
3448 
3449 	if (sbi->s_journal) {
3450 		ext4_init_journal_params(sb, sbi->s_journal);
3451 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3452 	}
3453 
3454 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
3455 		n_blocks_count > ext4_blocks_count(es)) {
3456 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
3457 			err = -EROFS;
3458 			goto restore_opts;
3459 		}
3460 
3461 		if (*flags & MS_RDONLY) {
3462 			/*
3463 			 * First of all, the unconditional stuff we have to do
3464 			 * to disable replay of the journal when we next remount
3465 			 */
3466 			sb->s_flags |= MS_RDONLY;
3467 
3468 			/*
3469 			 * OK, test if we are remounting a valid rw partition
3470 			 * readonly, and if so set the rdonly flag and then
3471 			 * mark the partition as valid again.
3472 			 */
3473 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3474 			    (sbi->s_mount_state & EXT4_VALID_FS))
3475 				es->s_state = cpu_to_le16(sbi->s_mount_state);
3476 
3477 			if (sbi->s_journal)
3478 				ext4_mark_recovery_complete(sb, es);
3479 		} else {
3480 			int ret;
3481 			if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3482 					~EXT4_FEATURE_RO_COMPAT_SUPP))) {
3483 				ext4_msg(sb, KERN_WARNING, "couldn't "
3484 				       "remount RDWR because of unsupported "
3485 				       "optional features (%x)",
3486 				(le32_to_cpu(sbi->s_es->s_feature_ro_compat) &
3487 					~EXT4_FEATURE_RO_COMPAT_SUPP));
3488 				err = -EROFS;
3489 				goto restore_opts;
3490 			}
3491 
3492 			/*
3493 			 * Make sure the group descriptor checksums
3494 			 * are sane.  If they aren't, refuse to remount r/w.
3495 			 */
3496 			for (g = 0; g < sbi->s_groups_count; g++) {
3497 				struct ext4_group_desc *gdp =
3498 					ext4_get_group_desc(sb, g, NULL);
3499 
3500 				if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3501 					ext4_msg(sb, KERN_ERR,
3502 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
3503 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3504 					       le16_to_cpu(gdp->bg_checksum));
3505 					err = -EINVAL;
3506 					goto restore_opts;
3507 				}
3508 			}
3509 
3510 			/*
3511 			 * If we have an unprocessed orphan list hanging
3512 			 * around from a previously readonly bdev mount,
3513 			 * require a full umount/remount for now.
3514 			 */
3515 			if (es->s_last_orphan) {
3516 				ext4_msg(sb, KERN_WARNING, "Couldn't "
3517 				       "remount RDWR because of unprocessed "
3518 				       "orphan inode list.  Please "
3519 				       "umount/remount instead");
3520 				err = -EINVAL;
3521 				goto restore_opts;
3522 			}
3523 
3524 			/*
3525 			 * Mounting a RDONLY partition read-write, so reread
3526 			 * and store the current valid flag.  (It may have
3527 			 * been changed by e2fsck since we originally mounted
3528 			 * the partition.)
3529 			 */
3530 			if (sbi->s_journal)
3531 				ext4_clear_journal_err(sb, es);
3532 			sbi->s_mount_state = le16_to_cpu(es->s_state);
3533 			if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3534 				goto restore_opts;
3535 			if (!ext4_setup_super(sb, es, 0))
3536 				sb->s_flags &= ~MS_RDONLY;
3537 		}
3538 	}
3539 	ext4_setup_system_zone(sb);
3540 	if (sbi->s_journal == NULL)
3541 		ext4_commit_super(sb, 1);
3542 
3543 #ifdef CONFIG_QUOTA
3544 	/* Release old quota file names */
3545 	for (i = 0; i < MAXQUOTAS; i++)
3546 		if (old_opts.s_qf_names[i] &&
3547 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3548 			kfree(old_opts.s_qf_names[i]);
3549 #endif
3550 	unlock_super(sb);
3551 	unlock_kernel();
3552 	return 0;
3553 
3554 restore_opts:
3555 	sb->s_flags = old_sb_flags;
3556 	sbi->s_mount_opt = old_opts.s_mount_opt;
3557 	sbi->s_resuid = old_opts.s_resuid;
3558 	sbi->s_resgid = old_opts.s_resgid;
3559 	sbi->s_commit_interval = old_opts.s_commit_interval;
3560 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
3561 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
3562 #ifdef CONFIG_QUOTA
3563 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3564 	for (i = 0; i < MAXQUOTAS; i++) {
3565 		if (sbi->s_qf_names[i] &&
3566 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3567 			kfree(sbi->s_qf_names[i]);
3568 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3569 	}
3570 #endif
3571 	unlock_super(sb);
3572 	unlock_kernel();
3573 	return err;
3574 }
3575 
3576 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
3577 {
3578 	struct super_block *sb = dentry->d_sb;
3579 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3580 	struct ext4_super_block *es = sbi->s_es;
3581 	u64 fsid;
3582 
3583 	if (test_opt(sb, MINIX_DF)) {
3584 		sbi->s_overhead_last = 0;
3585 	} else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3586 		ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3587 		ext4_fsblk_t overhead = 0;
3588 
3589 		/*
3590 		 * Compute the overhead (FS structures).  This is constant
3591 		 * for a given filesystem unless the number of block groups
3592 		 * changes so we cache the previous value until it does.
3593 		 */
3594 
3595 		/*
3596 		 * All of the blocks before first_data_block are
3597 		 * overhead
3598 		 */
3599 		overhead = le32_to_cpu(es->s_first_data_block);
3600 
3601 		/*
3602 		 * Add the overhead attributed to the superblock and
3603 		 * block group descriptors.  If the sparse superblocks
3604 		 * feature is turned on, then not all groups have this.
3605 		 */
3606 		for (i = 0; i < ngroups; i++) {
3607 			overhead += ext4_bg_has_super(sb, i) +
3608 				ext4_bg_num_gdb(sb, i);
3609 			cond_resched();
3610 		}
3611 
3612 		/*
3613 		 * Every block group has an inode bitmap, a block
3614 		 * bitmap, and an inode table.
3615 		 */
3616 		overhead += ngroups * (2 + sbi->s_itb_per_group);
3617 		sbi->s_overhead_last = overhead;
3618 		smp_wmb();
3619 		sbi->s_blocks_last = ext4_blocks_count(es);
3620 	}
3621 
3622 	buf->f_type = EXT4_SUPER_MAGIC;
3623 	buf->f_bsize = sb->s_blocksize;
3624 	buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3625 	buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
3626 		       percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
3627 	ext4_free_blocks_count_set(es, buf->f_bfree);
3628 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3629 	if (buf->f_bfree < ext4_r_blocks_count(es))
3630 		buf->f_bavail = 0;
3631 	buf->f_files = le32_to_cpu(es->s_inodes_count);
3632 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3633 	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
3634 	buf->f_namelen = EXT4_NAME_LEN;
3635 	fsid = le64_to_cpup((void *)es->s_uuid) ^
3636 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3637 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3638 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3639 
3640 	return 0;
3641 }
3642 
3643 /* Helper function for writing quotas on sync - we need to start transaction
3644  * before quota file is locked for write. Otherwise the are possible deadlocks:
3645  * Process 1                         Process 2
3646  * ext4_create()                     quota_sync()
3647  *   jbd2_journal_start()                  write_dquot()
3648  *   vfs_dq_init()                         down(dqio_mutex)
3649  *     down(dqio_mutex)                    jbd2_journal_start()
3650  *
3651  */
3652 
3653 #ifdef CONFIG_QUOTA
3654 
3655 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3656 {
3657 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3658 }
3659 
3660 static int ext4_write_dquot(struct dquot *dquot)
3661 {
3662 	int ret, err;
3663 	handle_t *handle;
3664 	struct inode *inode;
3665 
3666 	inode = dquot_to_inode(dquot);
3667 	handle = ext4_journal_start(inode,
3668 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3669 	if (IS_ERR(handle))
3670 		return PTR_ERR(handle);
3671 	ret = dquot_commit(dquot);
3672 	err = ext4_journal_stop(handle);
3673 	if (!ret)
3674 		ret = err;
3675 	return ret;
3676 }
3677 
3678 static int ext4_acquire_dquot(struct dquot *dquot)
3679 {
3680 	int ret, err;
3681 	handle_t *handle;
3682 
3683 	handle = ext4_journal_start(dquot_to_inode(dquot),
3684 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3685 	if (IS_ERR(handle))
3686 		return PTR_ERR(handle);
3687 	ret = dquot_acquire(dquot);
3688 	err = ext4_journal_stop(handle);
3689 	if (!ret)
3690 		ret = err;
3691 	return ret;
3692 }
3693 
3694 static int ext4_release_dquot(struct dquot *dquot)
3695 {
3696 	int ret, err;
3697 	handle_t *handle;
3698 
3699 	handle = ext4_journal_start(dquot_to_inode(dquot),
3700 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3701 	if (IS_ERR(handle)) {
3702 		/* Release dquot anyway to avoid endless cycle in dqput() */
3703 		dquot_release(dquot);
3704 		return PTR_ERR(handle);
3705 	}
3706 	ret = dquot_release(dquot);
3707 	err = ext4_journal_stop(handle);
3708 	if (!ret)
3709 		ret = err;
3710 	return ret;
3711 }
3712 
3713 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3714 {
3715 	/* Are we journaling quotas? */
3716 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3717 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3718 		dquot_mark_dquot_dirty(dquot);
3719 		return ext4_write_dquot(dquot);
3720 	} else {
3721 		return dquot_mark_dquot_dirty(dquot);
3722 	}
3723 }
3724 
3725 static int ext4_write_info(struct super_block *sb, int type)
3726 {
3727 	int ret, err;
3728 	handle_t *handle;
3729 
3730 	/* Data block + inode block */
3731 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
3732 	if (IS_ERR(handle))
3733 		return PTR_ERR(handle);
3734 	ret = dquot_commit_info(sb, type);
3735 	err = ext4_journal_stop(handle);
3736 	if (!ret)
3737 		ret = err;
3738 	return ret;
3739 }
3740 
3741 /*
3742  * Turn on quotas during mount time - we need to find
3743  * the quota file and such...
3744  */
3745 static int ext4_quota_on_mount(struct super_block *sb, int type)
3746 {
3747 	return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3748 				  EXT4_SB(sb)->s_jquota_fmt, type);
3749 }
3750 
3751 /*
3752  * Standard function to be called on quota_on
3753  */
3754 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3755 			 char *name, int remount)
3756 {
3757 	int err;
3758 	struct path path;
3759 
3760 	if (!test_opt(sb, QUOTA))
3761 		return -EINVAL;
3762 	/* When remounting, no checks are needed and in fact, name is NULL */
3763 	if (remount)
3764 		return vfs_quota_on(sb, type, format_id, name, remount);
3765 
3766 	err = kern_path(name, LOOKUP_FOLLOW, &path);
3767 	if (err)
3768 		return err;
3769 
3770 	/* Quotafile not on the same filesystem? */
3771 	if (path.mnt->mnt_sb != sb) {
3772 		path_put(&path);
3773 		return -EXDEV;
3774 	}
3775 	/* Journaling quota? */
3776 	if (EXT4_SB(sb)->s_qf_names[type]) {
3777 		/* Quotafile not in fs root? */
3778 		if (path.dentry->d_parent != sb->s_root)
3779 			ext4_msg(sb, KERN_WARNING,
3780 				"Quota file not on filesystem root. "
3781 				"Journaled quota will not work");
3782 	}
3783 
3784 	/*
3785 	 * When we journal data on quota file, we have to flush journal to see
3786 	 * all updates to the file when we bypass pagecache...
3787 	 */
3788 	if (EXT4_SB(sb)->s_journal &&
3789 	    ext4_should_journal_data(path.dentry->d_inode)) {
3790 		/*
3791 		 * We don't need to lock updates but journal_flush() could
3792 		 * otherwise be livelocked...
3793 		 */
3794 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3795 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3796 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3797 		if (err) {
3798 			path_put(&path);
3799 			return err;
3800 		}
3801 	}
3802 
3803 	err = vfs_quota_on_path(sb, type, format_id, &path);
3804 	path_put(&path);
3805 	return err;
3806 }
3807 
3808 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3809  * acquiring the locks... As quota files are never truncated and quota code
3810  * itself serializes the operations (and noone else should touch the files)
3811  * we don't have to be afraid of races */
3812 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3813 			       size_t len, loff_t off)
3814 {
3815 	struct inode *inode = sb_dqopt(sb)->files[type];
3816 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3817 	int err = 0;
3818 	int offset = off & (sb->s_blocksize - 1);
3819 	int tocopy;
3820 	size_t toread;
3821 	struct buffer_head *bh;
3822 	loff_t i_size = i_size_read(inode);
3823 
3824 	if (off > i_size)
3825 		return 0;
3826 	if (off+len > i_size)
3827 		len = i_size-off;
3828 	toread = len;
3829 	while (toread > 0) {
3830 		tocopy = sb->s_blocksize - offset < toread ?
3831 				sb->s_blocksize - offset : toread;
3832 		bh = ext4_bread(NULL, inode, blk, 0, &err);
3833 		if (err)
3834 			return err;
3835 		if (!bh)	/* A hole? */
3836 			memset(data, 0, tocopy);
3837 		else
3838 			memcpy(data, bh->b_data+offset, tocopy);
3839 		brelse(bh);
3840 		offset = 0;
3841 		toread -= tocopy;
3842 		data += tocopy;
3843 		blk++;
3844 	}
3845 	return len;
3846 }
3847 
3848 /* Write to quotafile (we know the transaction is already started and has
3849  * enough credits) */
3850 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3851 				const char *data, size_t len, loff_t off)
3852 {
3853 	struct inode *inode = sb_dqopt(sb)->files[type];
3854 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3855 	int err = 0;
3856 	int offset = off & (sb->s_blocksize - 1);
3857 	int tocopy;
3858 	int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3859 	size_t towrite = len;
3860 	struct buffer_head *bh;
3861 	handle_t *handle = journal_current_handle();
3862 
3863 	if (EXT4_SB(sb)->s_journal && !handle) {
3864 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
3865 			" cancelled because transaction is not started",
3866 			(unsigned long long)off, (unsigned long long)len);
3867 		return -EIO;
3868 	}
3869 	mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3870 	while (towrite > 0) {
3871 		tocopy = sb->s_blocksize - offset < towrite ?
3872 				sb->s_blocksize - offset : towrite;
3873 		bh = ext4_bread(handle, inode, blk, 1, &err);
3874 		if (!bh)
3875 			goto out;
3876 		if (journal_quota) {
3877 			err = ext4_journal_get_write_access(handle, bh);
3878 			if (err) {
3879 				brelse(bh);
3880 				goto out;
3881 			}
3882 		}
3883 		lock_buffer(bh);
3884 		memcpy(bh->b_data+offset, data, tocopy);
3885 		flush_dcache_page(bh->b_page);
3886 		unlock_buffer(bh);
3887 		if (journal_quota)
3888 			err = ext4_handle_dirty_metadata(handle, NULL, bh);
3889 		else {
3890 			/* Always do at least ordered writes for quotas */
3891 			err = ext4_jbd2_file_inode(handle, inode);
3892 			mark_buffer_dirty(bh);
3893 		}
3894 		brelse(bh);
3895 		if (err)
3896 			goto out;
3897 		offset = 0;
3898 		towrite -= tocopy;
3899 		data += tocopy;
3900 		blk++;
3901 	}
3902 out:
3903 	if (len == towrite) {
3904 		mutex_unlock(&inode->i_mutex);
3905 		return err;
3906 	}
3907 	if (inode->i_size < off+len-towrite) {
3908 		i_size_write(inode, off+len-towrite);
3909 		EXT4_I(inode)->i_disksize = inode->i_size;
3910 	}
3911 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3912 	ext4_mark_inode_dirty(handle, inode);
3913 	mutex_unlock(&inode->i_mutex);
3914 	return len - towrite;
3915 }
3916 
3917 #endif
3918 
3919 static int ext4_get_sb(struct file_system_type *fs_type, int flags,
3920 		       const char *dev_name, void *data, struct vfsmount *mnt)
3921 {
3922 	return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super,mnt);
3923 }
3924 
3925 static struct file_system_type ext4_fs_type = {
3926 	.owner		= THIS_MODULE,
3927 	.name		= "ext4",
3928 	.get_sb		= ext4_get_sb,
3929 	.kill_sb	= kill_block_super,
3930 	.fs_flags	= FS_REQUIRES_DEV,
3931 };
3932 
3933 #ifdef CONFIG_EXT4DEV_COMPAT
3934 static int ext4dev_get_sb(struct file_system_type *fs_type, int flags,
3935 			  const char *dev_name, void *data,struct vfsmount *mnt)
3936 {
3937 	printk(KERN_WARNING "EXT4-fs (%s): Update your userspace programs "
3938 	       "to mount using ext4\n", dev_name);
3939 	printk(KERN_WARNING "EXT4-fs (%s): ext4dev backwards compatibility "
3940 	       "will go away by 2.6.31\n", dev_name);
3941 	return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super,mnt);
3942 }
3943 
3944 static struct file_system_type ext4dev_fs_type = {
3945 	.owner		= THIS_MODULE,
3946 	.name		= "ext4dev",
3947 	.get_sb		= ext4dev_get_sb,
3948 	.kill_sb	= kill_block_super,
3949 	.fs_flags	= FS_REQUIRES_DEV,
3950 };
3951 MODULE_ALIAS("ext4dev");
3952 #endif
3953 
3954 static int __init init_ext4_fs(void)
3955 {
3956 	int err;
3957 
3958 	err = init_ext4_system_zone();
3959 	if (err)
3960 		return err;
3961 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
3962 	if (!ext4_kset)
3963 		goto out4;
3964 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
3965 	err = init_ext4_mballoc();
3966 	if (err)
3967 		goto out3;
3968 
3969 	err = init_ext4_xattr();
3970 	if (err)
3971 		goto out2;
3972 	err = init_inodecache();
3973 	if (err)
3974 		goto out1;
3975 	err = register_filesystem(&ext4_fs_type);
3976 	if (err)
3977 		goto out;
3978 #ifdef CONFIG_EXT4DEV_COMPAT
3979 	err = register_filesystem(&ext4dev_fs_type);
3980 	if (err) {
3981 		unregister_filesystem(&ext4_fs_type);
3982 		goto out;
3983 	}
3984 #endif
3985 	return 0;
3986 out:
3987 	destroy_inodecache();
3988 out1:
3989 	exit_ext4_xattr();
3990 out2:
3991 	exit_ext4_mballoc();
3992 out3:
3993 	remove_proc_entry("fs/ext4", NULL);
3994 	kset_unregister(ext4_kset);
3995 out4:
3996 	exit_ext4_system_zone();
3997 	return err;
3998 }
3999 
4000 static void __exit exit_ext4_fs(void)
4001 {
4002 	unregister_filesystem(&ext4_fs_type);
4003 #ifdef CONFIG_EXT4DEV_COMPAT
4004 	unregister_filesystem(&ext4dev_fs_type);
4005 #endif
4006 	destroy_inodecache();
4007 	exit_ext4_xattr();
4008 	exit_ext4_mballoc();
4009 	remove_proc_entry("fs/ext4", NULL);
4010 	kset_unregister(ext4_kset);
4011 	exit_ext4_system_zone();
4012 }
4013 
4014 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
4015 MODULE_DESCRIPTION("Fourth Extended Filesystem");
4016 MODULE_LICENSE("GPL");
4017 module_init(init_ext4_fs)
4018 module_exit(exit_ext4_fs)
4019