xref: /openbmc/linux/fs/ext4/super.c (revision e8e0929d)
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 #include "mballoc.h"
49 
50 #define CREATE_TRACE_POINTS
51 #include <trace/events/ext4.h>
52 
53 struct proc_dir_entry *ext4_proc_root;
54 static struct kset *ext4_kset;
55 
56 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
57 			     unsigned long journal_devnum);
58 static int ext4_commit_super(struct super_block *sb, int sync);
59 static void ext4_mark_recovery_complete(struct super_block *sb,
60 					struct ext4_super_block *es);
61 static void ext4_clear_journal_err(struct super_block *sb,
62 				   struct ext4_super_block *es);
63 static int ext4_sync_fs(struct super_block *sb, int wait);
64 static const char *ext4_decode_error(struct super_block *sb, int errno,
65 				     char nbuf[16]);
66 static int ext4_remount(struct super_block *sb, int *flags, char *data);
67 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
68 static int ext4_unfreeze(struct super_block *sb);
69 static void ext4_write_super(struct super_block *sb);
70 static int ext4_freeze(struct super_block *sb);
71 
72 
73 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
74 			       struct ext4_group_desc *bg)
75 {
76 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
77 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
78 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
79 }
80 
81 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
82 			       struct ext4_group_desc *bg)
83 {
84 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
85 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
86 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
87 }
88 
89 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
90 			      struct ext4_group_desc *bg)
91 {
92 	return le32_to_cpu(bg->bg_inode_table_lo) |
93 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
94 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
95 }
96 
97 __u32 ext4_free_blks_count(struct super_block *sb,
98 			      struct ext4_group_desc *bg)
99 {
100 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
101 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
102 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
103 }
104 
105 __u32 ext4_free_inodes_count(struct super_block *sb,
106 			      struct ext4_group_desc *bg)
107 {
108 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
109 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
110 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
111 }
112 
113 __u32 ext4_used_dirs_count(struct super_block *sb,
114 			      struct ext4_group_desc *bg)
115 {
116 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
117 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
118 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
119 }
120 
121 __u32 ext4_itable_unused_count(struct super_block *sb,
122 			      struct ext4_group_desc *bg)
123 {
124 	return le16_to_cpu(bg->bg_itable_unused_lo) |
125 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
126 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
127 }
128 
129 void ext4_block_bitmap_set(struct super_block *sb,
130 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
131 {
132 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
133 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
134 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
135 }
136 
137 void ext4_inode_bitmap_set(struct super_block *sb,
138 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
139 {
140 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
141 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
142 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
143 }
144 
145 void ext4_inode_table_set(struct super_block *sb,
146 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
147 {
148 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
149 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
150 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
151 }
152 
153 void ext4_free_blks_set(struct super_block *sb,
154 			  struct ext4_group_desc *bg, __u32 count)
155 {
156 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
157 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
158 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
159 }
160 
161 void ext4_free_inodes_set(struct super_block *sb,
162 			  struct ext4_group_desc *bg, __u32 count)
163 {
164 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
165 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
166 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
167 }
168 
169 void ext4_used_dirs_set(struct super_block *sb,
170 			  struct ext4_group_desc *bg, __u32 count)
171 {
172 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
173 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
174 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
175 }
176 
177 void ext4_itable_unused_set(struct super_block *sb,
178 			  struct ext4_group_desc *bg, __u32 count)
179 {
180 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
181 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
182 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
183 }
184 
185 
186 /* Just increment the non-pointer handle value */
187 static handle_t *ext4_get_nojournal(void)
188 {
189 	handle_t *handle = current->journal_info;
190 	unsigned long ref_cnt = (unsigned long)handle;
191 
192 	BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
193 
194 	ref_cnt++;
195 	handle = (handle_t *)ref_cnt;
196 
197 	current->journal_info = handle;
198 	return handle;
199 }
200 
201 
202 /* Decrement the non-pointer handle value */
203 static void ext4_put_nojournal(handle_t *handle)
204 {
205 	unsigned long ref_cnt = (unsigned long)handle;
206 
207 	BUG_ON(ref_cnt == 0);
208 
209 	ref_cnt--;
210 	handle = (handle_t *)ref_cnt;
211 
212 	current->journal_info = handle;
213 }
214 
215 /*
216  * Wrappers for jbd2_journal_start/end.
217  *
218  * The only special thing we need to do here is to make sure that all
219  * journal_end calls result in the superblock being marked dirty, so
220  * that sync() will call the filesystem's write_super callback if
221  * appropriate.
222  */
223 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
224 {
225 	journal_t *journal;
226 
227 	if (sb->s_flags & MS_RDONLY)
228 		return ERR_PTR(-EROFS);
229 
230 	/* Special case here: if the journal has aborted behind our
231 	 * backs (eg. EIO in the commit thread), then we still need to
232 	 * take the FS itself readonly cleanly. */
233 	journal = EXT4_SB(sb)->s_journal;
234 	if (journal) {
235 		if (is_journal_aborted(journal)) {
236 			ext4_abort(sb, __func__, "Detected aborted journal");
237 			return ERR_PTR(-EROFS);
238 		}
239 		return jbd2_journal_start(journal, nblocks);
240 	}
241 	return ext4_get_nojournal();
242 }
243 
244 /*
245  * The only special thing we need to do here is to make sure that all
246  * jbd2_journal_stop calls result in the superblock being marked dirty, so
247  * that sync() will call the filesystem's write_super callback if
248  * appropriate.
249  */
250 int __ext4_journal_stop(const char *where, handle_t *handle)
251 {
252 	struct super_block *sb;
253 	int err;
254 	int rc;
255 
256 	if (!ext4_handle_valid(handle)) {
257 		ext4_put_nojournal(handle);
258 		return 0;
259 	}
260 	sb = handle->h_transaction->t_journal->j_private;
261 	err = handle->h_err;
262 	rc = jbd2_journal_stop(handle);
263 
264 	if (!err)
265 		err = rc;
266 	if (err)
267 		__ext4_std_error(sb, where, err);
268 	return err;
269 }
270 
271 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
272 		struct buffer_head *bh, handle_t *handle, int err)
273 {
274 	char nbuf[16];
275 	const char *errstr = ext4_decode_error(NULL, err, nbuf);
276 
277 	BUG_ON(!ext4_handle_valid(handle));
278 
279 	if (bh)
280 		BUFFER_TRACE(bh, "abort");
281 
282 	if (!handle->h_err)
283 		handle->h_err = err;
284 
285 	if (is_handle_aborted(handle))
286 		return;
287 
288 	printk(KERN_ERR "%s: aborting transaction: %s in %s\n",
289 	       caller, errstr, err_fn);
290 
291 	jbd2_journal_abort_handle(handle);
292 }
293 
294 /* Deal with the reporting of failure conditions on a filesystem such as
295  * inconsistencies detected or read IO failures.
296  *
297  * On ext2, we can store the error state of the filesystem in the
298  * superblock.  That is not possible on ext4, because we may have other
299  * write ordering constraints on the superblock which prevent us from
300  * writing it out straight away; and given that the journal is about to
301  * be aborted, we can't rely on the current, or future, transactions to
302  * write out the superblock safely.
303  *
304  * We'll just use the jbd2_journal_abort() error code to record an error in
305  * the journal instead.  On recovery, the journal will compain about
306  * that error until we've noted it down and cleared it.
307  */
308 
309 static void ext4_handle_error(struct super_block *sb)
310 {
311 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
312 
313 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
314 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
315 
316 	if (sb->s_flags & MS_RDONLY)
317 		return;
318 
319 	if (!test_opt(sb, ERRORS_CONT)) {
320 		journal_t *journal = EXT4_SB(sb)->s_journal;
321 
322 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
323 		if (journal)
324 			jbd2_journal_abort(journal, -EIO);
325 	}
326 	if (test_opt(sb, ERRORS_RO)) {
327 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
328 		sb->s_flags |= MS_RDONLY;
329 	}
330 	ext4_commit_super(sb, 1);
331 	if (test_opt(sb, ERRORS_PANIC))
332 		panic("EXT4-fs (device %s): panic forced after error\n",
333 			sb->s_id);
334 }
335 
336 void ext4_error(struct super_block *sb, const char *function,
337 		const char *fmt, ...)
338 {
339 	va_list args;
340 
341 	va_start(args, fmt);
342 	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
343 	vprintk(fmt, args);
344 	printk("\n");
345 	va_end(args);
346 
347 	ext4_handle_error(sb);
348 }
349 
350 static const char *ext4_decode_error(struct super_block *sb, int errno,
351 				     char nbuf[16])
352 {
353 	char *errstr = NULL;
354 
355 	switch (errno) {
356 	case -EIO:
357 		errstr = "IO failure";
358 		break;
359 	case -ENOMEM:
360 		errstr = "Out of memory";
361 		break;
362 	case -EROFS:
363 		if (!sb || (EXT4_SB(sb)->s_journal &&
364 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
365 			errstr = "Journal has aborted";
366 		else
367 			errstr = "Readonly filesystem";
368 		break;
369 	default:
370 		/* If the caller passed in an extra buffer for unknown
371 		 * errors, textualise them now.  Else we just return
372 		 * NULL. */
373 		if (nbuf) {
374 			/* Check for truncated error codes... */
375 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
376 				errstr = nbuf;
377 		}
378 		break;
379 	}
380 
381 	return errstr;
382 }
383 
384 /* __ext4_std_error decodes expected errors from journaling functions
385  * automatically and invokes the appropriate error response.  */
386 
387 void __ext4_std_error(struct super_block *sb, const char *function, int errno)
388 {
389 	char nbuf[16];
390 	const char *errstr;
391 
392 	/* Special case: if the error is EROFS, and we're not already
393 	 * inside a transaction, then there's really no point in logging
394 	 * an error. */
395 	if (errno == -EROFS && journal_current_handle() == NULL &&
396 	    (sb->s_flags & MS_RDONLY))
397 		return;
398 
399 	errstr = ext4_decode_error(sb, errno, nbuf);
400 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s: %s\n",
401 	       sb->s_id, function, errstr);
402 
403 	ext4_handle_error(sb);
404 }
405 
406 /*
407  * ext4_abort is a much stronger failure handler than ext4_error.  The
408  * abort function may be used to deal with unrecoverable failures such
409  * as journal IO errors or ENOMEM at a critical moment in log management.
410  *
411  * We unconditionally force the filesystem into an ABORT|READONLY state,
412  * unless the error response on the fs has been set to panic in which
413  * case we take the easy way out and panic immediately.
414  */
415 
416 void ext4_abort(struct super_block *sb, const char *function,
417 		const char *fmt, ...)
418 {
419 	va_list args;
420 
421 	va_start(args, fmt);
422 	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
423 	vprintk(fmt, args);
424 	printk("\n");
425 	va_end(args);
426 
427 	if (test_opt(sb, ERRORS_PANIC))
428 		panic("EXT4-fs panic from previous error\n");
429 
430 	if (sb->s_flags & MS_RDONLY)
431 		return;
432 
433 	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
434 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
435 	sb->s_flags |= MS_RDONLY;
436 	EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
437 	if (EXT4_SB(sb)->s_journal)
438 		jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
439 }
440 
441 void ext4_msg (struct super_block * sb, const char *prefix,
442 		   const char *fmt, ...)
443 {
444 	va_list args;
445 
446 	va_start(args, fmt);
447 	printk("%sEXT4-fs (%s): ", prefix, sb->s_id);
448 	vprintk(fmt, args);
449 	printk("\n");
450 	va_end(args);
451 }
452 
453 void ext4_warning(struct super_block *sb, const char *function,
454 		  const char *fmt, ...)
455 {
456 	va_list args;
457 
458 	va_start(args, fmt);
459 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s: ",
460 	       sb->s_id, function);
461 	vprintk(fmt, args);
462 	printk("\n");
463 	va_end(args);
464 }
465 
466 void ext4_grp_locked_error(struct super_block *sb, ext4_group_t grp,
467 			   const char *function, const char *fmt, ...)
468 __releases(bitlock)
469 __acquires(bitlock)
470 {
471 	va_list args;
472 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
473 
474 	va_start(args, fmt);
475 	printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
476 	vprintk(fmt, args);
477 	printk("\n");
478 	va_end(args);
479 
480 	if (test_opt(sb, ERRORS_CONT)) {
481 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
482 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
483 		ext4_commit_super(sb, 0);
484 		return;
485 	}
486 	ext4_unlock_group(sb, grp);
487 	ext4_handle_error(sb);
488 	/*
489 	 * We only get here in the ERRORS_RO case; relocking the group
490 	 * may be dangerous, but nothing bad will happen since the
491 	 * filesystem will have already been marked read/only and the
492 	 * journal has been aborted.  We return 1 as a hint to callers
493 	 * who might what to use the return value from
494 	 * ext4_grp_locked_error() to distinguish beween the
495 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
496 	 * aggressively from the ext4 function in question, with a
497 	 * more appropriate error code.
498 	 */
499 	ext4_lock_group(sb, grp);
500 	return;
501 }
502 
503 void ext4_update_dynamic_rev(struct super_block *sb)
504 {
505 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
506 
507 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
508 		return;
509 
510 	ext4_warning(sb, __func__,
511 		     "updating to rev %d because of new feature flag, "
512 		     "running e2fsck is recommended",
513 		     EXT4_DYNAMIC_REV);
514 
515 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
516 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
517 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
518 	/* leave es->s_feature_*compat flags alone */
519 	/* es->s_uuid will be set by e2fsck if empty */
520 
521 	/*
522 	 * The rest of the superblock fields should be zero, and if not it
523 	 * means they are likely already in use, so leave them alone.  We
524 	 * can leave it up to e2fsck to clean up any inconsistencies there.
525 	 */
526 }
527 
528 /*
529  * Open the external journal device
530  */
531 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
532 {
533 	struct block_device *bdev;
534 	char b[BDEVNAME_SIZE];
535 
536 	bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
537 	if (IS_ERR(bdev))
538 		goto fail;
539 	return bdev;
540 
541 fail:
542 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
543 			__bdevname(dev, b), PTR_ERR(bdev));
544 	return NULL;
545 }
546 
547 /*
548  * Release the journal device
549  */
550 static int ext4_blkdev_put(struct block_device *bdev)
551 {
552 	bd_release(bdev);
553 	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
554 }
555 
556 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
557 {
558 	struct block_device *bdev;
559 	int ret = -ENODEV;
560 
561 	bdev = sbi->journal_bdev;
562 	if (bdev) {
563 		ret = ext4_blkdev_put(bdev);
564 		sbi->journal_bdev = NULL;
565 	}
566 	return ret;
567 }
568 
569 static inline struct inode *orphan_list_entry(struct list_head *l)
570 {
571 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
572 }
573 
574 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
575 {
576 	struct list_head *l;
577 
578 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
579 		 le32_to_cpu(sbi->s_es->s_last_orphan));
580 
581 	printk(KERN_ERR "sb_info orphan list:\n");
582 	list_for_each(l, &sbi->s_orphan) {
583 		struct inode *inode = orphan_list_entry(l);
584 		printk(KERN_ERR "  "
585 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
586 		       inode->i_sb->s_id, inode->i_ino, inode,
587 		       inode->i_mode, inode->i_nlink,
588 		       NEXT_ORPHAN(inode));
589 	}
590 }
591 
592 static void ext4_put_super(struct super_block *sb)
593 {
594 	struct ext4_sb_info *sbi = EXT4_SB(sb);
595 	struct ext4_super_block *es = sbi->s_es;
596 	int i, err;
597 
598 	flush_workqueue(sbi->dio_unwritten_wq);
599 	destroy_workqueue(sbi->dio_unwritten_wq);
600 
601 	lock_super(sb);
602 	lock_kernel();
603 	if (sb->s_dirt)
604 		ext4_commit_super(sb, 1);
605 
606 	ext4_release_system_zone(sb);
607 	ext4_mb_release(sb);
608 	ext4_ext_release(sb);
609 	ext4_xattr_put_super(sb);
610 	if (sbi->s_journal) {
611 		err = jbd2_journal_destroy(sbi->s_journal);
612 		sbi->s_journal = NULL;
613 		if (err < 0)
614 			ext4_abort(sb, __func__,
615 				   "Couldn't clean up the journal");
616 	}
617 	if (!(sb->s_flags & MS_RDONLY)) {
618 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
619 		es->s_state = cpu_to_le16(sbi->s_mount_state);
620 		ext4_commit_super(sb, 1);
621 	}
622 	if (sbi->s_proc) {
623 		remove_proc_entry(sb->s_id, ext4_proc_root);
624 	}
625 	kobject_del(&sbi->s_kobj);
626 
627 	for (i = 0; i < sbi->s_gdb_count; i++)
628 		brelse(sbi->s_group_desc[i]);
629 	kfree(sbi->s_group_desc);
630 	if (is_vmalloc_addr(sbi->s_flex_groups))
631 		vfree(sbi->s_flex_groups);
632 	else
633 		kfree(sbi->s_flex_groups);
634 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
635 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
636 	percpu_counter_destroy(&sbi->s_dirs_counter);
637 	percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
638 	brelse(sbi->s_sbh);
639 #ifdef CONFIG_QUOTA
640 	for (i = 0; i < MAXQUOTAS; i++)
641 		kfree(sbi->s_qf_names[i]);
642 #endif
643 
644 	/* Debugging code just in case the in-memory inode orphan list
645 	 * isn't empty.  The on-disk one can be non-empty if we've
646 	 * detected an error and taken the fs readonly, but the
647 	 * in-memory list had better be clean by this point. */
648 	if (!list_empty(&sbi->s_orphan))
649 		dump_orphan_list(sb, sbi);
650 	J_ASSERT(list_empty(&sbi->s_orphan));
651 
652 	invalidate_bdev(sb->s_bdev);
653 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
654 		/*
655 		 * Invalidate the journal device's buffers.  We don't want them
656 		 * floating about in memory - the physical journal device may
657 		 * hotswapped, and it breaks the `ro-after' testing code.
658 		 */
659 		sync_blockdev(sbi->journal_bdev);
660 		invalidate_bdev(sbi->journal_bdev);
661 		ext4_blkdev_remove(sbi);
662 	}
663 	sb->s_fs_info = NULL;
664 	/*
665 	 * Now that we are completely done shutting down the
666 	 * superblock, we need to actually destroy the kobject.
667 	 */
668 	unlock_kernel();
669 	unlock_super(sb);
670 	kobject_put(&sbi->s_kobj);
671 	wait_for_completion(&sbi->s_kobj_unregister);
672 	kfree(sbi->s_blockgroup_lock);
673 	kfree(sbi);
674 }
675 
676 static struct kmem_cache *ext4_inode_cachep;
677 
678 /*
679  * Called inside transaction, so use GFP_NOFS
680  */
681 static struct inode *ext4_alloc_inode(struct super_block *sb)
682 {
683 	struct ext4_inode_info *ei;
684 
685 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
686 	if (!ei)
687 		return NULL;
688 
689 	ei->vfs_inode.i_version = 1;
690 	ei->vfs_inode.i_data.writeback_index = 0;
691 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
692 	INIT_LIST_HEAD(&ei->i_prealloc_list);
693 	spin_lock_init(&ei->i_prealloc_lock);
694 	/*
695 	 * Note:  We can be called before EXT4_SB(sb)->s_journal is set,
696 	 * therefore it can be null here.  Don't check it, just initialize
697 	 * jinode.
698 	 */
699 	jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
700 	ei->i_reserved_data_blocks = 0;
701 	ei->i_reserved_meta_blocks = 0;
702 	ei->i_allocated_meta_blocks = 0;
703 	ei->i_delalloc_reserved_flag = 0;
704 	spin_lock_init(&(ei->i_block_reservation_lock));
705 	INIT_LIST_HEAD(&ei->i_aio_dio_complete_list);
706 	ei->cur_aio_dio = NULL;
707 
708 	return &ei->vfs_inode;
709 }
710 
711 static void ext4_destroy_inode(struct inode *inode)
712 {
713 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
714 		ext4_msg(inode->i_sb, KERN_ERR,
715 			 "Inode %lu (%p): orphan list check failed!",
716 			 inode->i_ino, EXT4_I(inode));
717 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
718 				EXT4_I(inode), sizeof(struct ext4_inode_info),
719 				true);
720 		dump_stack();
721 	}
722 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
723 }
724 
725 static void init_once(void *foo)
726 {
727 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
728 
729 	INIT_LIST_HEAD(&ei->i_orphan);
730 #ifdef CONFIG_EXT4_FS_XATTR
731 	init_rwsem(&ei->xattr_sem);
732 #endif
733 	init_rwsem(&ei->i_data_sem);
734 	inode_init_once(&ei->vfs_inode);
735 }
736 
737 static int init_inodecache(void)
738 {
739 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
740 					     sizeof(struct ext4_inode_info),
741 					     0, (SLAB_RECLAIM_ACCOUNT|
742 						SLAB_MEM_SPREAD),
743 					     init_once);
744 	if (ext4_inode_cachep == NULL)
745 		return -ENOMEM;
746 	return 0;
747 }
748 
749 static void destroy_inodecache(void)
750 {
751 	kmem_cache_destroy(ext4_inode_cachep);
752 }
753 
754 static void ext4_clear_inode(struct inode *inode)
755 {
756 	ext4_discard_preallocations(inode);
757 	if (EXT4_JOURNAL(inode))
758 		jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
759 				       &EXT4_I(inode)->jinode);
760 }
761 
762 static inline void ext4_show_quota_options(struct seq_file *seq,
763 					   struct super_block *sb)
764 {
765 #if defined(CONFIG_QUOTA)
766 	struct ext4_sb_info *sbi = EXT4_SB(sb);
767 
768 	if (sbi->s_jquota_fmt)
769 		seq_printf(seq, ",jqfmt=%s",
770 		(sbi->s_jquota_fmt == QFMT_VFS_OLD) ? "vfsold" : "vfsv0");
771 
772 	if (sbi->s_qf_names[USRQUOTA])
773 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
774 
775 	if (sbi->s_qf_names[GRPQUOTA])
776 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
777 
778 	if (sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA)
779 		seq_puts(seq, ",usrquota");
780 
781 	if (sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)
782 		seq_puts(seq, ",grpquota");
783 #endif
784 }
785 
786 /*
787  * Show an option if
788  *  - it's set to a non-default value OR
789  *  - if the per-sb default is different from the global default
790  */
791 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
792 {
793 	int def_errors;
794 	unsigned long def_mount_opts;
795 	struct super_block *sb = vfs->mnt_sb;
796 	struct ext4_sb_info *sbi = EXT4_SB(sb);
797 	struct ext4_super_block *es = sbi->s_es;
798 
799 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
800 	def_errors     = le16_to_cpu(es->s_errors);
801 
802 	if (sbi->s_sb_block != 1)
803 		seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
804 	if (test_opt(sb, MINIX_DF))
805 		seq_puts(seq, ",minixdf");
806 	if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
807 		seq_puts(seq, ",grpid");
808 	if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
809 		seq_puts(seq, ",nogrpid");
810 	if (sbi->s_resuid != EXT4_DEF_RESUID ||
811 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
812 		seq_printf(seq, ",resuid=%u", sbi->s_resuid);
813 	}
814 	if (sbi->s_resgid != EXT4_DEF_RESGID ||
815 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
816 		seq_printf(seq, ",resgid=%u", sbi->s_resgid);
817 	}
818 	if (test_opt(sb, ERRORS_RO)) {
819 		if (def_errors == EXT4_ERRORS_PANIC ||
820 		    def_errors == EXT4_ERRORS_CONTINUE) {
821 			seq_puts(seq, ",errors=remount-ro");
822 		}
823 	}
824 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
825 		seq_puts(seq, ",errors=continue");
826 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
827 		seq_puts(seq, ",errors=panic");
828 	if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
829 		seq_puts(seq, ",nouid32");
830 	if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
831 		seq_puts(seq, ",debug");
832 	if (test_opt(sb, OLDALLOC))
833 		seq_puts(seq, ",oldalloc");
834 #ifdef CONFIG_EXT4_FS_XATTR
835 	if (test_opt(sb, XATTR_USER) &&
836 		!(def_mount_opts & EXT4_DEFM_XATTR_USER))
837 		seq_puts(seq, ",user_xattr");
838 	if (!test_opt(sb, XATTR_USER) &&
839 	    (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
840 		seq_puts(seq, ",nouser_xattr");
841 	}
842 #endif
843 #ifdef CONFIG_EXT4_FS_POSIX_ACL
844 	if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
845 		seq_puts(seq, ",acl");
846 	if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
847 		seq_puts(seq, ",noacl");
848 #endif
849 	if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
850 		seq_printf(seq, ",commit=%u",
851 			   (unsigned) (sbi->s_commit_interval / HZ));
852 	}
853 	if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
854 		seq_printf(seq, ",min_batch_time=%u",
855 			   (unsigned) sbi->s_min_batch_time);
856 	}
857 	if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
858 		seq_printf(seq, ",max_batch_time=%u",
859 			   (unsigned) sbi->s_min_batch_time);
860 	}
861 
862 	/*
863 	 * We're changing the default of barrier mount option, so
864 	 * let's always display its mount state so it's clear what its
865 	 * status is.
866 	 */
867 	seq_puts(seq, ",barrier=");
868 	seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
869 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
870 		seq_puts(seq, ",journal_async_commit");
871 	if (test_opt(sb, NOBH))
872 		seq_puts(seq, ",nobh");
873 	if (test_opt(sb, I_VERSION))
874 		seq_puts(seq, ",i_version");
875 	if (!test_opt(sb, DELALLOC))
876 		seq_puts(seq, ",nodelalloc");
877 
878 
879 	if (sbi->s_stripe)
880 		seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
881 	/*
882 	 * journal mode get enabled in different ways
883 	 * So just print the value even if we didn't specify it
884 	 */
885 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
886 		seq_puts(seq, ",data=journal");
887 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
888 		seq_puts(seq, ",data=ordered");
889 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
890 		seq_puts(seq, ",data=writeback");
891 
892 	if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
893 		seq_printf(seq, ",inode_readahead_blks=%u",
894 			   sbi->s_inode_readahead_blks);
895 
896 	if (test_opt(sb, DATA_ERR_ABORT))
897 		seq_puts(seq, ",data_err=abort");
898 
899 	if (test_opt(sb, NO_AUTO_DA_ALLOC))
900 		seq_puts(seq, ",noauto_da_alloc");
901 
902 	ext4_show_quota_options(seq, sb);
903 
904 	return 0;
905 }
906 
907 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
908 					u64 ino, u32 generation)
909 {
910 	struct inode *inode;
911 
912 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
913 		return ERR_PTR(-ESTALE);
914 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
915 		return ERR_PTR(-ESTALE);
916 
917 	/* iget isn't really right if the inode is currently unallocated!!
918 	 *
919 	 * ext4_read_inode will return a bad_inode if the inode had been
920 	 * deleted, so we should be safe.
921 	 *
922 	 * Currently we don't know the generation for parent directory, so
923 	 * a generation of 0 means "accept any"
924 	 */
925 	inode = ext4_iget(sb, ino);
926 	if (IS_ERR(inode))
927 		return ERR_CAST(inode);
928 	if (generation && inode->i_generation != generation) {
929 		iput(inode);
930 		return ERR_PTR(-ESTALE);
931 	}
932 
933 	return inode;
934 }
935 
936 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
937 					int fh_len, int fh_type)
938 {
939 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
940 				    ext4_nfs_get_inode);
941 }
942 
943 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
944 					int fh_len, int fh_type)
945 {
946 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
947 				    ext4_nfs_get_inode);
948 }
949 
950 /*
951  * Try to release metadata pages (indirect blocks, directories) which are
952  * mapped via the block device.  Since these pages could have journal heads
953  * which would prevent try_to_free_buffers() from freeing them, we must use
954  * jbd2 layer's try_to_free_buffers() function to release them.
955  */
956 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
957 				 gfp_t wait)
958 {
959 	journal_t *journal = EXT4_SB(sb)->s_journal;
960 
961 	WARN_ON(PageChecked(page));
962 	if (!page_has_buffers(page))
963 		return 0;
964 	if (journal)
965 		return jbd2_journal_try_to_free_buffers(journal, page,
966 							wait & ~__GFP_WAIT);
967 	return try_to_free_buffers(page);
968 }
969 
970 #ifdef CONFIG_QUOTA
971 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
972 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
973 
974 static int ext4_write_dquot(struct dquot *dquot);
975 static int ext4_acquire_dquot(struct dquot *dquot);
976 static int ext4_release_dquot(struct dquot *dquot);
977 static int ext4_mark_dquot_dirty(struct dquot *dquot);
978 static int ext4_write_info(struct super_block *sb, int type);
979 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
980 				char *path, int remount);
981 static int ext4_quota_on_mount(struct super_block *sb, int type);
982 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
983 			       size_t len, loff_t off);
984 static ssize_t ext4_quota_write(struct super_block *sb, int type,
985 				const char *data, size_t len, loff_t off);
986 
987 static const struct dquot_operations ext4_quota_operations = {
988 	.initialize	= dquot_initialize,
989 	.drop		= dquot_drop,
990 	.alloc_space	= dquot_alloc_space,
991 	.reserve_space	= dquot_reserve_space,
992 	.claim_space	= dquot_claim_space,
993 	.release_rsv	= dquot_release_reserved_space,
994 	.get_reserved_space = ext4_get_reserved_space,
995 	.alloc_inode	= dquot_alloc_inode,
996 	.free_space	= dquot_free_space,
997 	.free_inode	= dquot_free_inode,
998 	.transfer	= dquot_transfer,
999 	.write_dquot	= ext4_write_dquot,
1000 	.acquire_dquot	= ext4_acquire_dquot,
1001 	.release_dquot	= ext4_release_dquot,
1002 	.mark_dirty	= ext4_mark_dquot_dirty,
1003 	.write_info	= ext4_write_info,
1004 	.alloc_dquot	= dquot_alloc,
1005 	.destroy_dquot	= dquot_destroy,
1006 };
1007 
1008 static const struct quotactl_ops ext4_qctl_operations = {
1009 	.quota_on	= ext4_quota_on,
1010 	.quota_off	= vfs_quota_off,
1011 	.quota_sync	= vfs_quota_sync,
1012 	.get_info	= vfs_get_dqinfo,
1013 	.set_info	= vfs_set_dqinfo,
1014 	.get_dqblk	= vfs_get_dqblk,
1015 	.set_dqblk	= vfs_set_dqblk
1016 };
1017 #endif
1018 
1019 static const struct super_operations ext4_sops = {
1020 	.alloc_inode	= ext4_alloc_inode,
1021 	.destroy_inode	= ext4_destroy_inode,
1022 	.write_inode	= ext4_write_inode,
1023 	.dirty_inode	= ext4_dirty_inode,
1024 	.delete_inode	= ext4_delete_inode,
1025 	.put_super	= ext4_put_super,
1026 	.sync_fs	= ext4_sync_fs,
1027 	.freeze_fs	= ext4_freeze,
1028 	.unfreeze_fs	= ext4_unfreeze,
1029 	.statfs		= ext4_statfs,
1030 	.remount_fs	= ext4_remount,
1031 	.clear_inode	= ext4_clear_inode,
1032 	.show_options	= ext4_show_options,
1033 #ifdef CONFIG_QUOTA
1034 	.quota_read	= ext4_quota_read,
1035 	.quota_write	= ext4_quota_write,
1036 #endif
1037 	.bdev_try_to_free_page = bdev_try_to_free_page,
1038 };
1039 
1040 static const struct super_operations ext4_nojournal_sops = {
1041 	.alloc_inode	= ext4_alloc_inode,
1042 	.destroy_inode	= ext4_destroy_inode,
1043 	.write_inode	= ext4_write_inode,
1044 	.dirty_inode	= ext4_dirty_inode,
1045 	.delete_inode	= ext4_delete_inode,
1046 	.write_super	= ext4_write_super,
1047 	.put_super	= ext4_put_super,
1048 	.statfs		= ext4_statfs,
1049 	.remount_fs	= ext4_remount,
1050 	.clear_inode	= ext4_clear_inode,
1051 	.show_options	= ext4_show_options,
1052 #ifdef CONFIG_QUOTA
1053 	.quota_read	= ext4_quota_read,
1054 	.quota_write	= ext4_quota_write,
1055 #endif
1056 	.bdev_try_to_free_page = bdev_try_to_free_page,
1057 };
1058 
1059 static const struct export_operations ext4_export_ops = {
1060 	.fh_to_dentry = ext4_fh_to_dentry,
1061 	.fh_to_parent = ext4_fh_to_parent,
1062 	.get_parent = ext4_get_parent,
1063 };
1064 
1065 enum {
1066 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1067 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1068 	Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1069 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1070 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1071 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1072 	Opt_journal_update, Opt_journal_dev,
1073 	Opt_journal_checksum, Opt_journal_async_commit,
1074 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1075 	Opt_data_err_abort, Opt_data_err_ignore,
1076 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1077 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
1078 	Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err, Opt_resize,
1079 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1080 	Opt_stripe, Opt_delalloc, Opt_nodelalloc,
1081 	Opt_block_validity, Opt_noblock_validity,
1082 	Opt_inode_readahead_blks, Opt_journal_ioprio
1083 };
1084 
1085 static const match_table_t tokens = {
1086 	{Opt_bsd_df, "bsddf"},
1087 	{Opt_minix_df, "minixdf"},
1088 	{Opt_grpid, "grpid"},
1089 	{Opt_grpid, "bsdgroups"},
1090 	{Opt_nogrpid, "nogrpid"},
1091 	{Opt_nogrpid, "sysvgroups"},
1092 	{Opt_resgid, "resgid=%u"},
1093 	{Opt_resuid, "resuid=%u"},
1094 	{Opt_sb, "sb=%u"},
1095 	{Opt_err_cont, "errors=continue"},
1096 	{Opt_err_panic, "errors=panic"},
1097 	{Opt_err_ro, "errors=remount-ro"},
1098 	{Opt_nouid32, "nouid32"},
1099 	{Opt_debug, "debug"},
1100 	{Opt_oldalloc, "oldalloc"},
1101 	{Opt_orlov, "orlov"},
1102 	{Opt_user_xattr, "user_xattr"},
1103 	{Opt_nouser_xattr, "nouser_xattr"},
1104 	{Opt_acl, "acl"},
1105 	{Opt_noacl, "noacl"},
1106 	{Opt_noload, "noload"},
1107 	{Opt_nobh, "nobh"},
1108 	{Opt_bh, "bh"},
1109 	{Opt_commit, "commit=%u"},
1110 	{Opt_min_batch_time, "min_batch_time=%u"},
1111 	{Opt_max_batch_time, "max_batch_time=%u"},
1112 	{Opt_journal_update, "journal=update"},
1113 	{Opt_journal_dev, "journal_dev=%u"},
1114 	{Opt_journal_checksum, "journal_checksum"},
1115 	{Opt_journal_async_commit, "journal_async_commit"},
1116 	{Opt_abort, "abort"},
1117 	{Opt_data_journal, "data=journal"},
1118 	{Opt_data_ordered, "data=ordered"},
1119 	{Opt_data_writeback, "data=writeback"},
1120 	{Opt_data_err_abort, "data_err=abort"},
1121 	{Opt_data_err_ignore, "data_err=ignore"},
1122 	{Opt_offusrjquota, "usrjquota="},
1123 	{Opt_usrjquota, "usrjquota=%s"},
1124 	{Opt_offgrpjquota, "grpjquota="},
1125 	{Opt_grpjquota, "grpjquota=%s"},
1126 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1127 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1128 	{Opt_grpquota, "grpquota"},
1129 	{Opt_noquota, "noquota"},
1130 	{Opt_quota, "quota"},
1131 	{Opt_usrquota, "usrquota"},
1132 	{Opt_barrier, "barrier=%u"},
1133 	{Opt_barrier, "barrier"},
1134 	{Opt_nobarrier, "nobarrier"},
1135 	{Opt_i_version, "i_version"},
1136 	{Opt_stripe, "stripe=%u"},
1137 	{Opt_resize, "resize"},
1138 	{Opt_delalloc, "delalloc"},
1139 	{Opt_nodelalloc, "nodelalloc"},
1140 	{Opt_block_validity, "block_validity"},
1141 	{Opt_noblock_validity, "noblock_validity"},
1142 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1143 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1144 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1145 	{Opt_auto_da_alloc, "auto_da_alloc"},
1146 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1147 	{Opt_err, NULL},
1148 };
1149 
1150 static ext4_fsblk_t get_sb_block(void **data)
1151 {
1152 	ext4_fsblk_t	sb_block;
1153 	char		*options = (char *) *data;
1154 
1155 	if (!options || strncmp(options, "sb=", 3) != 0)
1156 		return 1;	/* Default location */
1157 
1158 	options += 3;
1159 	/* TODO: use simple_strtoll with >32bit ext4 */
1160 	sb_block = simple_strtoul(options, &options, 0);
1161 	if (*options && *options != ',') {
1162 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1163 		       (char *) *data);
1164 		return 1;
1165 	}
1166 	if (*options == ',')
1167 		options++;
1168 	*data = (void *) options;
1169 
1170 	return sb_block;
1171 }
1172 
1173 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1174 
1175 static int parse_options(char *options, struct super_block *sb,
1176 			 unsigned long *journal_devnum,
1177 			 unsigned int *journal_ioprio,
1178 			 ext4_fsblk_t *n_blocks_count, int is_remount)
1179 {
1180 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1181 	char *p;
1182 	substring_t args[MAX_OPT_ARGS];
1183 	int data_opt = 0;
1184 	int option;
1185 #ifdef CONFIG_QUOTA
1186 	int qtype, qfmt;
1187 	char *qname;
1188 #endif
1189 
1190 	if (!options)
1191 		return 1;
1192 
1193 	while ((p = strsep(&options, ",")) != NULL) {
1194 		int token;
1195 		if (!*p)
1196 			continue;
1197 
1198 		token = match_token(p, tokens, args);
1199 		switch (token) {
1200 		case Opt_bsd_df:
1201 			clear_opt(sbi->s_mount_opt, MINIX_DF);
1202 			break;
1203 		case Opt_minix_df:
1204 			set_opt(sbi->s_mount_opt, MINIX_DF);
1205 			break;
1206 		case Opt_grpid:
1207 			set_opt(sbi->s_mount_opt, GRPID);
1208 			break;
1209 		case Opt_nogrpid:
1210 			clear_opt(sbi->s_mount_opt, GRPID);
1211 			break;
1212 		case Opt_resuid:
1213 			if (match_int(&args[0], &option))
1214 				return 0;
1215 			sbi->s_resuid = option;
1216 			break;
1217 		case Opt_resgid:
1218 			if (match_int(&args[0], &option))
1219 				return 0;
1220 			sbi->s_resgid = option;
1221 			break;
1222 		case Opt_sb:
1223 			/* handled by get_sb_block() instead of here */
1224 			/* *sb_block = match_int(&args[0]); */
1225 			break;
1226 		case Opt_err_panic:
1227 			clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1228 			clear_opt(sbi->s_mount_opt, ERRORS_RO);
1229 			set_opt(sbi->s_mount_opt, ERRORS_PANIC);
1230 			break;
1231 		case Opt_err_ro:
1232 			clear_opt(sbi->s_mount_opt, ERRORS_CONT);
1233 			clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1234 			set_opt(sbi->s_mount_opt, ERRORS_RO);
1235 			break;
1236 		case Opt_err_cont:
1237 			clear_opt(sbi->s_mount_opt, ERRORS_RO);
1238 			clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
1239 			set_opt(sbi->s_mount_opt, ERRORS_CONT);
1240 			break;
1241 		case Opt_nouid32:
1242 			set_opt(sbi->s_mount_opt, NO_UID32);
1243 			break;
1244 		case Opt_debug:
1245 			set_opt(sbi->s_mount_opt, DEBUG);
1246 			break;
1247 		case Opt_oldalloc:
1248 			set_opt(sbi->s_mount_opt, OLDALLOC);
1249 			break;
1250 		case Opt_orlov:
1251 			clear_opt(sbi->s_mount_opt, OLDALLOC);
1252 			break;
1253 #ifdef CONFIG_EXT4_FS_XATTR
1254 		case Opt_user_xattr:
1255 			set_opt(sbi->s_mount_opt, XATTR_USER);
1256 			break;
1257 		case Opt_nouser_xattr:
1258 			clear_opt(sbi->s_mount_opt, XATTR_USER);
1259 			break;
1260 #else
1261 		case Opt_user_xattr:
1262 		case Opt_nouser_xattr:
1263 			ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1264 			break;
1265 #endif
1266 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1267 		case Opt_acl:
1268 			set_opt(sbi->s_mount_opt, POSIX_ACL);
1269 			break;
1270 		case Opt_noacl:
1271 			clear_opt(sbi->s_mount_opt, POSIX_ACL);
1272 			break;
1273 #else
1274 		case Opt_acl:
1275 		case Opt_noacl:
1276 			ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1277 			break;
1278 #endif
1279 		case Opt_journal_update:
1280 			/* @@@ FIXME */
1281 			/* Eventually we will want to be able to create
1282 			   a journal file here.  For now, only allow the
1283 			   user to specify an existing inode to be the
1284 			   journal file. */
1285 			if (is_remount) {
1286 				ext4_msg(sb, KERN_ERR,
1287 					 "Cannot specify journal on remount");
1288 				return 0;
1289 			}
1290 			set_opt(sbi->s_mount_opt, UPDATE_JOURNAL);
1291 			break;
1292 		case Opt_journal_dev:
1293 			if (is_remount) {
1294 				ext4_msg(sb, KERN_ERR,
1295 					"Cannot specify journal on remount");
1296 				return 0;
1297 			}
1298 			if (match_int(&args[0], &option))
1299 				return 0;
1300 			*journal_devnum = option;
1301 			break;
1302 		case Opt_journal_checksum:
1303 			break;	/* Kept for backwards compatibility */
1304 		case Opt_journal_async_commit:
1305 			set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
1306 			break;
1307 		case Opt_noload:
1308 			set_opt(sbi->s_mount_opt, NOLOAD);
1309 			break;
1310 		case Opt_commit:
1311 			if (match_int(&args[0], &option))
1312 				return 0;
1313 			if (option < 0)
1314 				return 0;
1315 			if (option == 0)
1316 				option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1317 			sbi->s_commit_interval = HZ * option;
1318 			break;
1319 		case Opt_max_batch_time:
1320 			if (match_int(&args[0], &option))
1321 				return 0;
1322 			if (option < 0)
1323 				return 0;
1324 			if (option == 0)
1325 				option = EXT4_DEF_MAX_BATCH_TIME;
1326 			sbi->s_max_batch_time = option;
1327 			break;
1328 		case Opt_min_batch_time:
1329 			if (match_int(&args[0], &option))
1330 				return 0;
1331 			if (option < 0)
1332 				return 0;
1333 			sbi->s_min_batch_time = option;
1334 			break;
1335 		case Opt_data_journal:
1336 			data_opt = EXT4_MOUNT_JOURNAL_DATA;
1337 			goto datacheck;
1338 		case Opt_data_ordered:
1339 			data_opt = EXT4_MOUNT_ORDERED_DATA;
1340 			goto datacheck;
1341 		case Opt_data_writeback:
1342 			data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1343 		datacheck:
1344 			if (is_remount) {
1345 				if ((sbi->s_mount_opt & EXT4_MOUNT_DATA_FLAGS)
1346 						!= data_opt) {
1347 					ext4_msg(sb, KERN_ERR,
1348 						"Cannot change data mode on remount");
1349 					return 0;
1350 				}
1351 			} else {
1352 				sbi->s_mount_opt &= ~EXT4_MOUNT_DATA_FLAGS;
1353 				sbi->s_mount_opt |= data_opt;
1354 			}
1355 			break;
1356 		case Opt_data_err_abort:
1357 			set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1358 			break;
1359 		case Opt_data_err_ignore:
1360 			clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
1361 			break;
1362 #ifdef CONFIG_QUOTA
1363 		case Opt_usrjquota:
1364 			qtype = USRQUOTA;
1365 			goto set_qf_name;
1366 		case Opt_grpjquota:
1367 			qtype = GRPQUOTA;
1368 set_qf_name:
1369 			if (sb_any_quota_loaded(sb) &&
1370 			    !sbi->s_qf_names[qtype]) {
1371 				ext4_msg(sb, KERN_ERR,
1372 				       "Cannot change journaled "
1373 				       "quota options when quota turned on");
1374 				return 0;
1375 			}
1376 			qname = match_strdup(&args[0]);
1377 			if (!qname) {
1378 				ext4_msg(sb, KERN_ERR,
1379 					"Not enough memory for "
1380 					"storing quotafile name");
1381 				return 0;
1382 			}
1383 			if (sbi->s_qf_names[qtype] &&
1384 			    strcmp(sbi->s_qf_names[qtype], qname)) {
1385 				ext4_msg(sb, KERN_ERR,
1386 					"%s quota file already "
1387 					"specified", QTYPE2NAME(qtype));
1388 				kfree(qname);
1389 				return 0;
1390 			}
1391 			sbi->s_qf_names[qtype] = qname;
1392 			if (strchr(sbi->s_qf_names[qtype], '/')) {
1393 				ext4_msg(sb, KERN_ERR,
1394 					"quotafile must be on "
1395 					"filesystem root");
1396 				kfree(sbi->s_qf_names[qtype]);
1397 				sbi->s_qf_names[qtype] = NULL;
1398 				return 0;
1399 			}
1400 			set_opt(sbi->s_mount_opt, QUOTA);
1401 			break;
1402 		case Opt_offusrjquota:
1403 			qtype = USRQUOTA;
1404 			goto clear_qf_name;
1405 		case Opt_offgrpjquota:
1406 			qtype = GRPQUOTA;
1407 clear_qf_name:
1408 			if (sb_any_quota_loaded(sb) &&
1409 			    sbi->s_qf_names[qtype]) {
1410 				ext4_msg(sb, KERN_ERR, "Cannot change "
1411 					"journaled quota options when "
1412 					"quota turned on");
1413 				return 0;
1414 			}
1415 			/*
1416 			 * The space will be released later when all options
1417 			 * are confirmed to be correct
1418 			 */
1419 			sbi->s_qf_names[qtype] = NULL;
1420 			break;
1421 		case Opt_jqfmt_vfsold:
1422 			qfmt = QFMT_VFS_OLD;
1423 			goto set_qf_format;
1424 		case Opt_jqfmt_vfsv0:
1425 			qfmt = QFMT_VFS_V0;
1426 set_qf_format:
1427 			if (sb_any_quota_loaded(sb) &&
1428 			    sbi->s_jquota_fmt != qfmt) {
1429 				ext4_msg(sb, KERN_ERR, "Cannot change "
1430 					"journaled quota options when "
1431 					"quota turned on");
1432 				return 0;
1433 			}
1434 			sbi->s_jquota_fmt = qfmt;
1435 			break;
1436 		case Opt_quota:
1437 		case Opt_usrquota:
1438 			set_opt(sbi->s_mount_opt, QUOTA);
1439 			set_opt(sbi->s_mount_opt, USRQUOTA);
1440 			break;
1441 		case Opt_grpquota:
1442 			set_opt(sbi->s_mount_opt, QUOTA);
1443 			set_opt(sbi->s_mount_opt, GRPQUOTA);
1444 			break;
1445 		case Opt_noquota:
1446 			if (sb_any_quota_loaded(sb)) {
1447 				ext4_msg(sb, KERN_ERR, "Cannot change quota "
1448 					"options when quota turned on");
1449 				return 0;
1450 			}
1451 			clear_opt(sbi->s_mount_opt, QUOTA);
1452 			clear_opt(sbi->s_mount_opt, USRQUOTA);
1453 			clear_opt(sbi->s_mount_opt, GRPQUOTA);
1454 			break;
1455 #else
1456 		case Opt_quota:
1457 		case Opt_usrquota:
1458 		case Opt_grpquota:
1459 			ext4_msg(sb, KERN_ERR,
1460 				"quota options not supported");
1461 			break;
1462 		case Opt_usrjquota:
1463 		case Opt_grpjquota:
1464 		case Opt_offusrjquota:
1465 		case Opt_offgrpjquota:
1466 		case Opt_jqfmt_vfsold:
1467 		case Opt_jqfmt_vfsv0:
1468 			ext4_msg(sb, KERN_ERR,
1469 				"journaled quota options not supported");
1470 			break;
1471 		case Opt_noquota:
1472 			break;
1473 #endif
1474 		case Opt_abort:
1475 			sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1476 			break;
1477 		case Opt_nobarrier:
1478 			clear_opt(sbi->s_mount_opt, BARRIER);
1479 			break;
1480 		case Opt_barrier:
1481 			if (match_int(&args[0], &option)) {
1482 				set_opt(sbi->s_mount_opt, BARRIER);
1483 				break;
1484 			}
1485 			if (option)
1486 				set_opt(sbi->s_mount_opt, BARRIER);
1487 			else
1488 				clear_opt(sbi->s_mount_opt, BARRIER);
1489 			break;
1490 		case Opt_ignore:
1491 			break;
1492 		case Opt_resize:
1493 			if (!is_remount) {
1494 				ext4_msg(sb, KERN_ERR,
1495 					"resize option only available "
1496 					"for remount");
1497 				return 0;
1498 			}
1499 			if (match_int(&args[0], &option) != 0)
1500 				return 0;
1501 			*n_blocks_count = option;
1502 			break;
1503 		case Opt_nobh:
1504 			set_opt(sbi->s_mount_opt, NOBH);
1505 			break;
1506 		case Opt_bh:
1507 			clear_opt(sbi->s_mount_opt, NOBH);
1508 			break;
1509 		case Opt_i_version:
1510 			set_opt(sbi->s_mount_opt, I_VERSION);
1511 			sb->s_flags |= MS_I_VERSION;
1512 			break;
1513 		case Opt_nodelalloc:
1514 			clear_opt(sbi->s_mount_opt, DELALLOC);
1515 			break;
1516 		case Opt_stripe:
1517 			if (match_int(&args[0], &option))
1518 				return 0;
1519 			if (option < 0)
1520 				return 0;
1521 			sbi->s_stripe = option;
1522 			break;
1523 		case Opt_delalloc:
1524 			set_opt(sbi->s_mount_opt, DELALLOC);
1525 			break;
1526 		case Opt_block_validity:
1527 			set_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1528 			break;
1529 		case Opt_noblock_validity:
1530 			clear_opt(sbi->s_mount_opt, BLOCK_VALIDITY);
1531 			break;
1532 		case Opt_inode_readahead_blks:
1533 			if (match_int(&args[0], &option))
1534 				return 0;
1535 			if (option < 0 || option > (1 << 30))
1536 				return 0;
1537 			if (!is_power_of_2(option)) {
1538 				ext4_msg(sb, KERN_ERR,
1539 					 "EXT4-fs: inode_readahead_blks"
1540 					 " must be a power of 2");
1541 				return 0;
1542 			}
1543 			sbi->s_inode_readahead_blks = option;
1544 			break;
1545 		case Opt_journal_ioprio:
1546 			if (match_int(&args[0], &option))
1547 				return 0;
1548 			if (option < 0 || option > 7)
1549 				break;
1550 			*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1551 							    option);
1552 			break;
1553 		case Opt_noauto_da_alloc:
1554 			set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1555 			break;
1556 		case Opt_auto_da_alloc:
1557 			if (match_int(&args[0], &option)) {
1558 				clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1559 				break;
1560 			}
1561 			if (option)
1562 				clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
1563 			else
1564 				set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
1565 			break;
1566 		default:
1567 			ext4_msg(sb, KERN_ERR,
1568 			       "Unrecognized mount option \"%s\" "
1569 			       "or missing value", p);
1570 			return 0;
1571 		}
1572 	}
1573 #ifdef CONFIG_QUOTA
1574 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1575 		if ((sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA) &&
1576 		     sbi->s_qf_names[USRQUOTA])
1577 			clear_opt(sbi->s_mount_opt, USRQUOTA);
1578 
1579 		if ((sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA) &&
1580 		     sbi->s_qf_names[GRPQUOTA])
1581 			clear_opt(sbi->s_mount_opt, GRPQUOTA);
1582 
1583 		if ((sbi->s_qf_names[USRQUOTA] &&
1584 				(sbi->s_mount_opt & EXT4_MOUNT_GRPQUOTA)) ||
1585 		    (sbi->s_qf_names[GRPQUOTA] &&
1586 				(sbi->s_mount_opt & EXT4_MOUNT_USRQUOTA))) {
1587 			ext4_msg(sb, KERN_ERR, "old and new quota "
1588 					"format mixing");
1589 			return 0;
1590 		}
1591 
1592 		if (!sbi->s_jquota_fmt) {
1593 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1594 					"not specified");
1595 			return 0;
1596 		}
1597 	} else {
1598 		if (sbi->s_jquota_fmt) {
1599 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1600 					"specified with no journaling "
1601 					"enabled");
1602 			return 0;
1603 		}
1604 	}
1605 #endif
1606 	return 1;
1607 }
1608 
1609 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1610 			    int read_only)
1611 {
1612 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1613 	int res = 0;
1614 
1615 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1616 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1617 			 "forcing read-only mode");
1618 		res = MS_RDONLY;
1619 	}
1620 	if (read_only)
1621 		return res;
1622 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1623 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1624 			 "running e2fsck is recommended");
1625 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1626 		ext4_msg(sb, KERN_WARNING,
1627 			 "warning: mounting fs with errors, "
1628 			 "running e2fsck is recommended");
1629 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1630 		 le16_to_cpu(es->s_mnt_count) >=
1631 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1632 		ext4_msg(sb, KERN_WARNING,
1633 			 "warning: maximal mount count reached, "
1634 			 "running e2fsck is recommended");
1635 	else if (le32_to_cpu(es->s_checkinterval) &&
1636 		(le32_to_cpu(es->s_lastcheck) +
1637 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1638 		ext4_msg(sb, KERN_WARNING,
1639 			 "warning: checktime reached, "
1640 			 "running e2fsck is recommended");
1641 	if (!sbi->s_journal)
1642 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1643 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1644 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1645 	le16_add_cpu(&es->s_mnt_count, 1);
1646 	es->s_mtime = cpu_to_le32(get_seconds());
1647 	ext4_update_dynamic_rev(sb);
1648 	if (sbi->s_journal)
1649 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1650 
1651 	ext4_commit_super(sb, 1);
1652 	if (test_opt(sb, DEBUG))
1653 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1654 				"bpg=%lu, ipg=%lu, mo=%04x]\n",
1655 			sb->s_blocksize,
1656 			sbi->s_groups_count,
1657 			EXT4_BLOCKS_PER_GROUP(sb),
1658 			EXT4_INODES_PER_GROUP(sb),
1659 			sbi->s_mount_opt);
1660 
1661 	return res;
1662 }
1663 
1664 static int ext4_fill_flex_info(struct super_block *sb)
1665 {
1666 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1667 	struct ext4_group_desc *gdp = NULL;
1668 	ext4_group_t flex_group_count;
1669 	ext4_group_t flex_group;
1670 	int groups_per_flex = 0;
1671 	size_t size;
1672 	int i;
1673 
1674 	if (!sbi->s_es->s_log_groups_per_flex) {
1675 		sbi->s_log_groups_per_flex = 0;
1676 		return 1;
1677 	}
1678 
1679 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1680 	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1681 
1682 	/* We allocate both existing and potentially added groups */
1683 	flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1684 			((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1685 			      EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1686 	size = flex_group_count * sizeof(struct flex_groups);
1687 	sbi->s_flex_groups = kzalloc(size, GFP_KERNEL);
1688 	if (sbi->s_flex_groups == NULL) {
1689 		sbi->s_flex_groups = vmalloc(size);
1690 		if (sbi->s_flex_groups)
1691 			memset(sbi->s_flex_groups, 0, size);
1692 	}
1693 	if (sbi->s_flex_groups == NULL) {
1694 		ext4_msg(sb, KERN_ERR, "not enough memory for "
1695 				"%u flex groups", flex_group_count);
1696 		goto failed;
1697 	}
1698 
1699 	for (i = 0; i < sbi->s_groups_count; i++) {
1700 		gdp = ext4_get_group_desc(sb, i, NULL);
1701 
1702 		flex_group = ext4_flex_group(sbi, i);
1703 		atomic_add(ext4_free_inodes_count(sb, gdp),
1704 			   &sbi->s_flex_groups[flex_group].free_inodes);
1705 		atomic_add(ext4_free_blks_count(sb, gdp),
1706 			   &sbi->s_flex_groups[flex_group].free_blocks);
1707 		atomic_add(ext4_used_dirs_count(sb, gdp),
1708 			   &sbi->s_flex_groups[flex_group].used_dirs);
1709 	}
1710 
1711 	return 1;
1712 failed:
1713 	return 0;
1714 }
1715 
1716 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1717 			    struct ext4_group_desc *gdp)
1718 {
1719 	__u16 crc = 0;
1720 
1721 	if (sbi->s_es->s_feature_ro_compat &
1722 	    cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1723 		int offset = offsetof(struct ext4_group_desc, bg_checksum);
1724 		__le32 le_group = cpu_to_le32(block_group);
1725 
1726 		crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1727 		crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1728 		crc = crc16(crc, (__u8 *)gdp, offset);
1729 		offset += sizeof(gdp->bg_checksum); /* skip checksum */
1730 		/* for checksum of struct ext4_group_desc do the rest...*/
1731 		if ((sbi->s_es->s_feature_incompat &
1732 		     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1733 		    offset < le16_to_cpu(sbi->s_es->s_desc_size))
1734 			crc = crc16(crc, (__u8 *)gdp + offset,
1735 				    le16_to_cpu(sbi->s_es->s_desc_size) -
1736 					offset);
1737 	}
1738 
1739 	return cpu_to_le16(crc);
1740 }
1741 
1742 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1743 				struct ext4_group_desc *gdp)
1744 {
1745 	if ((sbi->s_es->s_feature_ro_compat &
1746 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1747 	    (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1748 		return 0;
1749 
1750 	return 1;
1751 }
1752 
1753 /* Called at mount-time, super-block is locked */
1754 static int ext4_check_descriptors(struct super_block *sb)
1755 {
1756 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1757 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1758 	ext4_fsblk_t last_block;
1759 	ext4_fsblk_t block_bitmap;
1760 	ext4_fsblk_t inode_bitmap;
1761 	ext4_fsblk_t inode_table;
1762 	int flexbg_flag = 0;
1763 	ext4_group_t i;
1764 
1765 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1766 		flexbg_flag = 1;
1767 
1768 	ext4_debug("Checking group descriptors");
1769 
1770 	for (i = 0; i < sbi->s_groups_count; i++) {
1771 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1772 
1773 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
1774 			last_block = ext4_blocks_count(sbi->s_es) - 1;
1775 		else
1776 			last_block = first_block +
1777 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
1778 
1779 		block_bitmap = ext4_block_bitmap(sb, gdp);
1780 		if (block_bitmap < first_block || block_bitmap > last_block) {
1781 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1782 			       "Block bitmap for group %u not in group "
1783 			       "(block %llu)!", i, block_bitmap);
1784 			return 0;
1785 		}
1786 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
1787 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
1788 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1789 			       "Inode bitmap for group %u not in group "
1790 			       "(block %llu)!", i, inode_bitmap);
1791 			return 0;
1792 		}
1793 		inode_table = ext4_inode_table(sb, gdp);
1794 		if (inode_table < first_block ||
1795 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
1796 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1797 			       "Inode table for group %u not in group "
1798 			       "(block %llu)!", i, inode_table);
1799 			return 0;
1800 		}
1801 		ext4_lock_group(sb, i);
1802 		if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
1803 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1804 				 "Checksum for group %u failed (%u!=%u)",
1805 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
1806 				     gdp)), le16_to_cpu(gdp->bg_checksum));
1807 			if (!(sb->s_flags & MS_RDONLY)) {
1808 				ext4_unlock_group(sb, i);
1809 				return 0;
1810 			}
1811 		}
1812 		ext4_unlock_group(sb, i);
1813 		if (!flexbg_flag)
1814 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
1815 	}
1816 
1817 	ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
1818 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
1819 	return 1;
1820 }
1821 
1822 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
1823  * the superblock) which were deleted from all directories, but held open by
1824  * a process at the time of a crash.  We walk the list and try to delete these
1825  * inodes at recovery time (only with a read-write filesystem).
1826  *
1827  * In order to keep the orphan inode chain consistent during traversal (in
1828  * case of crash during recovery), we link each inode into the superblock
1829  * orphan list_head and handle it the same way as an inode deletion during
1830  * normal operation (which journals the operations for us).
1831  *
1832  * We only do an iget() and an iput() on each inode, which is very safe if we
1833  * accidentally point at an in-use or already deleted inode.  The worst that
1834  * can happen in this case is that we get a "bit already cleared" message from
1835  * ext4_free_inode().  The only reason we would point at a wrong inode is if
1836  * e2fsck was run on this filesystem, and it must have already done the orphan
1837  * inode cleanup for us, so we can safely abort without any further action.
1838  */
1839 static void ext4_orphan_cleanup(struct super_block *sb,
1840 				struct ext4_super_block *es)
1841 {
1842 	unsigned int s_flags = sb->s_flags;
1843 	int nr_orphans = 0, nr_truncates = 0;
1844 #ifdef CONFIG_QUOTA
1845 	int i;
1846 #endif
1847 	if (!es->s_last_orphan) {
1848 		jbd_debug(4, "no orphan inodes to clean up\n");
1849 		return;
1850 	}
1851 
1852 	if (bdev_read_only(sb->s_bdev)) {
1853 		ext4_msg(sb, KERN_ERR, "write access "
1854 			"unavailable, skipping orphan cleanup");
1855 		return;
1856 	}
1857 
1858 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
1859 		if (es->s_last_orphan)
1860 			jbd_debug(1, "Errors on filesystem, "
1861 				  "clearing orphan list.\n");
1862 		es->s_last_orphan = 0;
1863 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
1864 		return;
1865 	}
1866 
1867 	if (s_flags & MS_RDONLY) {
1868 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
1869 		sb->s_flags &= ~MS_RDONLY;
1870 	}
1871 #ifdef CONFIG_QUOTA
1872 	/* Needed for iput() to work correctly and not trash data */
1873 	sb->s_flags |= MS_ACTIVE;
1874 	/* Turn on quotas so that they are updated correctly */
1875 	for (i = 0; i < MAXQUOTAS; i++) {
1876 		if (EXT4_SB(sb)->s_qf_names[i]) {
1877 			int ret = ext4_quota_on_mount(sb, i);
1878 			if (ret < 0)
1879 				ext4_msg(sb, KERN_ERR,
1880 					"Cannot turn on journaled "
1881 					"quota: error %d", ret);
1882 		}
1883 	}
1884 #endif
1885 
1886 	while (es->s_last_orphan) {
1887 		struct inode *inode;
1888 
1889 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
1890 		if (IS_ERR(inode)) {
1891 			es->s_last_orphan = 0;
1892 			break;
1893 		}
1894 
1895 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1896 		vfs_dq_init(inode);
1897 		if (inode->i_nlink) {
1898 			ext4_msg(sb, KERN_DEBUG,
1899 				"%s: truncating inode %lu to %lld bytes",
1900 				__func__, inode->i_ino, inode->i_size);
1901 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
1902 				  inode->i_ino, inode->i_size);
1903 			ext4_truncate(inode);
1904 			nr_truncates++;
1905 		} else {
1906 			ext4_msg(sb, KERN_DEBUG,
1907 				"%s: deleting unreferenced inode %lu",
1908 				__func__, inode->i_ino);
1909 			jbd_debug(2, "deleting unreferenced inode %lu\n",
1910 				  inode->i_ino);
1911 			nr_orphans++;
1912 		}
1913 		iput(inode);  /* The delete magic happens here! */
1914 	}
1915 
1916 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
1917 
1918 	if (nr_orphans)
1919 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
1920 		       PLURAL(nr_orphans));
1921 	if (nr_truncates)
1922 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
1923 		       PLURAL(nr_truncates));
1924 #ifdef CONFIG_QUOTA
1925 	/* Turn quotas off */
1926 	for (i = 0; i < MAXQUOTAS; i++) {
1927 		if (sb_dqopt(sb)->files[i])
1928 			vfs_quota_off(sb, i, 0);
1929 	}
1930 #endif
1931 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
1932 }
1933 
1934 /*
1935  * Maximal extent format file size.
1936  * Resulting logical blkno at s_maxbytes must fit in our on-disk
1937  * extent format containers, within a sector_t, and within i_blocks
1938  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
1939  * so that won't be a limiting factor.
1940  *
1941  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
1942  */
1943 static loff_t ext4_max_size(int blkbits, int has_huge_files)
1944 {
1945 	loff_t res;
1946 	loff_t upper_limit = MAX_LFS_FILESIZE;
1947 
1948 	/* small i_blocks in vfs inode? */
1949 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1950 		/*
1951 		 * CONFIG_LBDAF is not enabled implies the inode
1952 		 * i_block represent total blocks in 512 bytes
1953 		 * 32 == size of vfs inode i_blocks * 8
1954 		 */
1955 		upper_limit = (1LL << 32) - 1;
1956 
1957 		/* total blocks in file system block size */
1958 		upper_limit >>= (blkbits - 9);
1959 		upper_limit <<= blkbits;
1960 	}
1961 
1962 	/* 32-bit extent-start container, ee_block */
1963 	res = 1LL << 32;
1964 	res <<= blkbits;
1965 	res -= 1;
1966 
1967 	/* Sanity check against vm- & vfs- imposed limits */
1968 	if (res > upper_limit)
1969 		res = upper_limit;
1970 
1971 	return res;
1972 }
1973 
1974 /*
1975  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
1976  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
1977  * We need to be 1 filesystem block less than the 2^48 sector limit.
1978  */
1979 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
1980 {
1981 	loff_t res = EXT4_NDIR_BLOCKS;
1982 	int meta_blocks;
1983 	loff_t upper_limit;
1984 	/* This is calculated to be the largest file size for a dense, block
1985 	 * mapped file such that the file's total number of 512-byte sectors,
1986 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
1987 	 *
1988 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
1989 	 * number of 512-byte sectors of the file.
1990 	 */
1991 
1992 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
1993 		/*
1994 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
1995 		 * the inode i_block field represents total file blocks in
1996 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
1997 		 */
1998 		upper_limit = (1LL << 32) - 1;
1999 
2000 		/* total blocks in file system block size */
2001 		upper_limit >>= (bits - 9);
2002 
2003 	} else {
2004 		/*
2005 		 * We use 48 bit ext4_inode i_blocks
2006 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2007 		 * represent total number of blocks in
2008 		 * file system block size
2009 		 */
2010 		upper_limit = (1LL << 48) - 1;
2011 
2012 	}
2013 
2014 	/* indirect blocks */
2015 	meta_blocks = 1;
2016 	/* double indirect blocks */
2017 	meta_blocks += 1 + (1LL << (bits-2));
2018 	/* tripple indirect blocks */
2019 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2020 
2021 	upper_limit -= meta_blocks;
2022 	upper_limit <<= bits;
2023 
2024 	res += 1LL << (bits-2);
2025 	res += 1LL << (2*(bits-2));
2026 	res += 1LL << (3*(bits-2));
2027 	res <<= bits;
2028 	if (res > upper_limit)
2029 		res = upper_limit;
2030 
2031 	if (res > MAX_LFS_FILESIZE)
2032 		res = MAX_LFS_FILESIZE;
2033 
2034 	return res;
2035 }
2036 
2037 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2038 				   ext4_fsblk_t logical_sb_block, int nr)
2039 {
2040 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2041 	ext4_group_t bg, first_meta_bg;
2042 	int has_super = 0;
2043 
2044 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2045 
2046 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2047 	    nr < first_meta_bg)
2048 		return logical_sb_block + nr + 1;
2049 	bg = sbi->s_desc_per_block * nr;
2050 	if (ext4_bg_has_super(sb, bg))
2051 		has_super = 1;
2052 
2053 	return (has_super + ext4_group_first_block_no(sb, bg));
2054 }
2055 
2056 /**
2057  * ext4_get_stripe_size: Get the stripe size.
2058  * @sbi: In memory super block info
2059  *
2060  * If we have specified it via mount option, then
2061  * use the mount option value. If the value specified at mount time is
2062  * greater than the blocks per group use the super block value.
2063  * If the super block value is greater than blocks per group return 0.
2064  * Allocator needs it be less than blocks per group.
2065  *
2066  */
2067 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2068 {
2069 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2070 	unsigned long stripe_width =
2071 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2072 
2073 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2074 		return sbi->s_stripe;
2075 
2076 	if (stripe_width <= sbi->s_blocks_per_group)
2077 		return stripe_width;
2078 
2079 	if (stride <= sbi->s_blocks_per_group)
2080 		return stride;
2081 
2082 	return 0;
2083 }
2084 
2085 /* sysfs supprt */
2086 
2087 struct ext4_attr {
2088 	struct attribute attr;
2089 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2090 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2091 			 const char *, size_t);
2092 	int offset;
2093 };
2094 
2095 static int parse_strtoul(const char *buf,
2096 		unsigned long max, unsigned long *value)
2097 {
2098 	char *endp;
2099 
2100 	while (*buf && isspace(*buf))
2101 		buf++;
2102 	*value = simple_strtoul(buf, &endp, 0);
2103 	while (*endp && isspace(*endp))
2104 		endp++;
2105 	if (*endp || *value > max)
2106 		return -EINVAL;
2107 
2108 	return 0;
2109 }
2110 
2111 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2112 					      struct ext4_sb_info *sbi,
2113 					      char *buf)
2114 {
2115 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2116 			(s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2117 }
2118 
2119 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2120 					 struct ext4_sb_info *sbi, char *buf)
2121 {
2122 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2123 
2124 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2125 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2126 			 sbi->s_sectors_written_start) >> 1);
2127 }
2128 
2129 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2130 					  struct ext4_sb_info *sbi, char *buf)
2131 {
2132 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2133 
2134 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2135 			sbi->s_kbytes_written +
2136 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2137 			  EXT4_SB(sb)->s_sectors_written_start) >> 1));
2138 }
2139 
2140 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2141 					  struct ext4_sb_info *sbi,
2142 					  const char *buf, size_t count)
2143 {
2144 	unsigned long t;
2145 
2146 	if (parse_strtoul(buf, 0x40000000, &t))
2147 		return -EINVAL;
2148 
2149 	if (!is_power_of_2(t))
2150 		return -EINVAL;
2151 
2152 	sbi->s_inode_readahead_blks = t;
2153 	return count;
2154 }
2155 
2156 static ssize_t sbi_ui_show(struct ext4_attr *a,
2157 			   struct ext4_sb_info *sbi, char *buf)
2158 {
2159 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2160 
2161 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2162 }
2163 
2164 static ssize_t sbi_ui_store(struct ext4_attr *a,
2165 			    struct ext4_sb_info *sbi,
2166 			    const char *buf, size_t count)
2167 {
2168 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2169 	unsigned long t;
2170 
2171 	if (parse_strtoul(buf, 0xffffffff, &t))
2172 		return -EINVAL;
2173 	*ui = t;
2174 	return count;
2175 }
2176 
2177 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2178 static struct ext4_attr ext4_attr_##_name = {			\
2179 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2180 	.show	= _show,					\
2181 	.store	= _store,					\
2182 	.offset = offsetof(struct ext4_sb_info, _elname),	\
2183 }
2184 #define EXT4_ATTR(name, mode, show, store) \
2185 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2186 
2187 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2188 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2189 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2190 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2191 #define ATTR_LIST(name) &ext4_attr_##name.attr
2192 
2193 EXT4_RO_ATTR(delayed_allocation_blocks);
2194 EXT4_RO_ATTR(session_write_kbytes);
2195 EXT4_RO_ATTR(lifetime_write_kbytes);
2196 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2197 		 inode_readahead_blks_store, s_inode_readahead_blks);
2198 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2199 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2200 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2201 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2202 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2203 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2204 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2205 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2206 
2207 static struct attribute *ext4_attrs[] = {
2208 	ATTR_LIST(delayed_allocation_blocks),
2209 	ATTR_LIST(session_write_kbytes),
2210 	ATTR_LIST(lifetime_write_kbytes),
2211 	ATTR_LIST(inode_readahead_blks),
2212 	ATTR_LIST(inode_goal),
2213 	ATTR_LIST(mb_stats),
2214 	ATTR_LIST(mb_max_to_scan),
2215 	ATTR_LIST(mb_min_to_scan),
2216 	ATTR_LIST(mb_order2_req),
2217 	ATTR_LIST(mb_stream_req),
2218 	ATTR_LIST(mb_group_prealloc),
2219 	ATTR_LIST(max_writeback_mb_bump),
2220 	NULL,
2221 };
2222 
2223 static ssize_t ext4_attr_show(struct kobject *kobj,
2224 			      struct attribute *attr, char *buf)
2225 {
2226 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2227 						s_kobj);
2228 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2229 
2230 	return a->show ? a->show(a, sbi, buf) : 0;
2231 }
2232 
2233 static ssize_t ext4_attr_store(struct kobject *kobj,
2234 			       struct attribute *attr,
2235 			       const char *buf, size_t len)
2236 {
2237 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2238 						s_kobj);
2239 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2240 
2241 	return a->store ? a->store(a, sbi, buf, len) : 0;
2242 }
2243 
2244 static void ext4_sb_release(struct kobject *kobj)
2245 {
2246 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2247 						s_kobj);
2248 	complete(&sbi->s_kobj_unregister);
2249 }
2250 
2251 
2252 static struct sysfs_ops ext4_attr_ops = {
2253 	.show	= ext4_attr_show,
2254 	.store	= ext4_attr_store,
2255 };
2256 
2257 static struct kobj_type ext4_ktype = {
2258 	.default_attrs	= ext4_attrs,
2259 	.sysfs_ops	= &ext4_attr_ops,
2260 	.release	= ext4_sb_release,
2261 };
2262 
2263 /*
2264  * Check whether this filesystem can be mounted based on
2265  * the features present and the RDONLY/RDWR mount requested.
2266  * Returns 1 if this filesystem can be mounted as requested,
2267  * 0 if it cannot be.
2268  */
2269 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2270 {
2271 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2272 		ext4_msg(sb, KERN_ERR,
2273 			"Couldn't mount because of "
2274 			"unsupported optional features (%x)",
2275 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2276 			~EXT4_FEATURE_INCOMPAT_SUPP));
2277 		return 0;
2278 	}
2279 
2280 	if (readonly)
2281 		return 1;
2282 
2283 	/* Check that feature set is OK for a read-write mount */
2284 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2285 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2286 			 "unsupported optional features (%x)",
2287 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2288 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2289 		return 0;
2290 	}
2291 	/*
2292 	 * Large file size enabled file system can only be mounted
2293 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2294 	 */
2295 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2296 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2297 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2298 				 "cannot be mounted RDWR without "
2299 				 "CONFIG_LBDAF");
2300 			return 0;
2301 		}
2302 	}
2303 	return 1;
2304 }
2305 
2306 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
2307 				__releases(kernel_lock)
2308 				__acquires(kernel_lock)
2309 {
2310 	struct buffer_head *bh;
2311 	struct ext4_super_block *es = NULL;
2312 	struct ext4_sb_info *sbi;
2313 	ext4_fsblk_t block;
2314 	ext4_fsblk_t sb_block = get_sb_block(&data);
2315 	ext4_fsblk_t logical_sb_block;
2316 	unsigned long offset = 0;
2317 	unsigned long journal_devnum = 0;
2318 	unsigned long def_mount_opts;
2319 	struct inode *root;
2320 	char *cp;
2321 	const char *descr;
2322 	int ret = -EINVAL;
2323 	int blocksize;
2324 	unsigned int db_count;
2325 	unsigned int i;
2326 	int needs_recovery, has_huge_files;
2327 	__u64 blocks_count;
2328 	int err;
2329 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2330 
2331 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2332 	if (!sbi)
2333 		return -ENOMEM;
2334 
2335 	sbi->s_blockgroup_lock =
2336 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
2337 	if (!sbi->s_blockgroup_lock) {
2338 		kfree(sbi);
2339 		return -ENOMEM;
2340 	}
2341 	sb->s_fs_info = sbi;
2342 	sbi->s_mount_opt = 0;
2343 	sbi->s_resuid = EXT4_DEF_RESUID;
2344 	sbi->s_resgid = EXT4_DEF_RESGID;
2345 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
2346 	sbi->s_sb_block = sb_block;
2347 	sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part,
2348 						      sectors[1]);
2349 
2350 	unlock_kernel();
2351 
2352 	/* Cleanup superblock name */
2353 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
2354 		*cp = '!';
2355 
2356 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
2357 	if (!blocksize) {
2358 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
2359 		goto out_fail;
2360 	}
2361 
2362 	/*
2363 	 * The ext4 superblock will not be buffer aligned for other than 1kB
2364 	 * block sizes.  We need to calculate the offset from buffer start.
2365 	 */
2366 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
2367 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2368 		offset = do_div(logical_sb_block, blocksize);
2369 	} else {
2370 		logical_sb_block = sb_block;
2371 	}
2372 
2373 	if (!(bh = sb_bread(sb, logical_sb_block))) {
2374 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
2375 		goto out_fail;
2376 	}
2377 	/*
2378 	 * Note: s_es must be initialized as soon as possible because
2379 	 *       some ext4 macro-instructions depend on its value
2380 	 */
2381 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
2382 	sbi->s_es = es;
2383 	sb->s_magic = le16_to_cpu(es->s_magic);
2384 	if (sb->s_magic != EXT4_SUPER_MAGIC)
2385 		goto cantfind_ext4;
2386 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
2387 
2388 	/* Set defaults before we parse the mount options */
2389 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
2390 	if (def_mount_opts & EXT4_DEFM_DEBUG)
2391 		set_opt(sbi->s_mount_opt, DEBUG);
2392 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
2393 		set_opt(sbi->s_mount_opt, GRPID);
2394 	if (def_mount_opts & EXT4_DEFM_UID16)
2395 		set_opt(sbi->s_mount_opt, NO_UID32);
2396 #ifdef CONFIG_EXT4_FS_XATTR
2397 	if (def_mount_opts & EXT4_DEFM_XATTR_USER)
2398 		set_opt(sbi->s_mount_opt, XATTR_USER);
2399 #endif
2400 #ifdef CONFIG_EXT4_FS_POSIX_ACL
2401 	if (def_mount_opts & EXT4_DEFM_ACL)
2402 		set_opt(sbi->s_mount_opt, POSIX_ACL);
2403 #endif
2404 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
2405 		sbi->s_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
2406 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
2407 		sbi->s_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
2408 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
2409 		sbi->s_mount_opt |= EXT4_MOUNT_WRITEBACK_DATA;
2410 
2411 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
2412 		set_opt(sbi->s_mount_opt, ERRORS_PANIC);
2413 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
2414 		set_opt(sbi->s_mount_opt, ERRORS_CONT);
2415 	else
2416 		set_opt(sbi->s_mount_opt, ERRORS_RO);
2417 
2418 	sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
2419 	sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
2420 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
2421 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
2422 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
2423 
2424 	set_opt(sbi->s_mount_opt, BARRIER);
2425 
2426 	/*
2427 	 * enable delayed allocation by default
2428 	 * Use -o nodelalloc to turn it off
2429 	 */
2430 	set_opt(sbi->s_mount_opt, DELALLOC);
2431 
2432 	if (!parse_options((char *) data, sb, &journal_devnum,
2433 			   &journal_ioprio, NULL, 0))
2434 		goto failed_mount;
2435 
2436 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
2437 		((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
2438 
2439 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
2440 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
2441 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
2442 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
2443 		ext4_msg(sb, KERN_WARNING,
2444 		       "feature flags set on rev 0 fs, "
2445 		       "running e2fsck is recommended");
2446 
2447 	/*
2448 	 * Check feature flags regardless of the revision level, since we
2449 	 * previously didn't change the revision level when setting the flags,
2450 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
2451 	 */
2452 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
2453 		goto failed_mount;
2454 
2455 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
2456 
2457 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
2458 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
2459 		ext4_msg(sb, KERN_ERR,
2460 		       "Unsupported filesystem blocksize %d", blocksize);
2461 		goto failed_mount;
2462 	}
2463 
2464 	if (sb->s_blocksize != blocksize) {
2465 		/* Validate the filesystem blocksize */
2466 		if (!sb_set_blocksize(sb, blocksize)) {
2467 			ext4_msg(sb, KERN_ERR, "bad block size %d",
2468 					blocksize);
2469 			goto failed_mount;
2470 		}
2471 
2472 		brelse(bh);
2473 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
2474 		offset = do_div(logical_sb_block, blocksize);
2475 		bh = sb_bread(sb, logical_sb_block);
2476 		if (!bh) {
2477 			ext4_msg(sb, KERN_ERR,
2478 			       "Can't read superblock on 2nd try");
2479 			goto failed_mount;
2480 		}
2481 		es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
2482 		sbi->s_es = es;
2483 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
2484 			ext4_msg(sb, KERN_ERR,
2485 			       "Magic mismatch, very weird!");
2486 			goto failed_mount;
2487 		}
2488 	}
2489 
2490 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
2491 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
2492 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
2493 						      has_huge_files);
2494 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
2495 
2496 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
2497 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
2498 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
2499 	} else {
2500 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
2501 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
2502 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
2503 		    (!is_power_of_2(sbi->s_inode_size)) ||
2504 		    (sbi->s_inode_size > blocksize)) {
2505 			ext4_msg(sb, KERN_ERR,
2506 			       "unsupported inode size: %d",
2507 			       sbi->s_inode_size);
2508 			goto failed_mount;
2509 		}
2510 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
2511 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
2512 	}
2513 
2514 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
2515 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
2516 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
2517 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
2518 		    !is_power_of_2(sbi->s_desc_size)) {
2519 			ext4_msg(sb, KERN_ERR,
2520 			       "unsupported descriptor size %lu",
2521 			       sbi->s_desc_size);
2522 			goto failed_mount;
2523 		}
2524 	} else
2525 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
2526 
2527 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
2528 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
2529 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
2530 		goto cantfind_ext4;
2531 
2532 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
2533 	if (sbi->s_inodes_per_block == 0)
2534 		goto cantfind_ext4;
2535 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
2536 					sbi->s_inodes_per_block;
2537 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
2538 	sbi->s_sbh = bh;
2539 	sbi->s_mount_state = le16_to_cpu(es->s_state);
2540 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
2541 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
2542 
2543 	for (i = 0; i < 4; i++)
2544 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
2545 	sbi->s_def_hash_version = es->s_def_hash_version;
2546 	i = le32_to_cpu(es->s_flags);
2547 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
2548 		sbi->s_hash_unsigned = 3;
2549 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
2550 #ifdef __CHAR_UNSIGNED__
2551 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
2552 		sbi->s_hash_unsigned = 3;
2553 #else
2554 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
2555 #endif
2556 		sb->s_dirt = 1;
2557 	}
2558 
2559 	if (sbi->s_blocks_per_group > blocksize * 8) {
2560 		ext4_msg(sb, KERN_ERR,
2561 		       "#blocks per group too big: %lu",
2562 		       sbi->s_blocks_per_group);
2563 		goto failed_mount;
2564 	}
2565 	if (sbi->s_inodes_per_group > blocksize * 8) {
2566 		ext4_msg(sb, KERN_ERR,
2567 		       "#inodes per group too big: %lu",
2568 		       sbi->s_inodes_per_group);
2569 		goto failed_mount;
2570 	}
2571 
2572 	/*
2573 	 * Test whether we have more sectors than will fit in sector_t,
2574 	 * and whether the max offset is addressable by the page cache.
2575 	 */
2576 	if ((ext4_blocks_count(es) >
2577 	     (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) ||
2578 	    (ext4_blocks_count(es) >
2579 	     (pgoff_t)(~0ULL) >> (PAGE_CACHE_SHIFT - sb->s_blocksize_bits))) {
2580 		ext4_msg(sb, KERN_ERR, "filesystem"
2581 			 " too large to mount safely on this system");
2582 		if (sizeof(sector_t) < 8)
2583 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
2584 		ret = -EFBIG;
2585 		goto failed_mount;
2586 	}
2587 
2588 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
2589 		goto cantfind_ext4;
2590 
2591 	/* check blocks count against device size */
2592 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
2593 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
2594 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
2595 		       "exceeds size of device (%llu blocks)",
2596 		       ext4_blocks_count(es), blocks_count);
2597 		goto failed_mount;
2598 	}
2599 
2600 	/*
2601 	 * It makes no sense for the first data block to be beyond the end
2602 	 * of the filesystem.
2603 	 */
2604 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
2605                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
2606 			 "block %u is beyond end of filesystem (%llu)",
2607 			 le32_to_cpu(es->s_first_data_block),
2608 			 ext4_blocks_count(es));
2609 		goto failed_mount;
2610 	}
2611 	blocks_count = (ext4_blocks_count(es) -
2612 			le32_to_cpu(es->s_first_data_block) +
2613 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
2614 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
2615 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
2616 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
2617 		       "(block count %llu, first data block %u, "
2618 		       "blocks per group %lu)", sbi->s_groups_count,
2619 		       ext4_blocks_count(es),
2620 		       le32_to_cpu(es->s_first_data_block),
2621 		       EXT4_BLOCKS_PER_GROUP(sb));
2622 		goto failed_mount;
2623 	}
2624 	sbi->s_groups_count = blocks_count;
2625 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
2626 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
2627 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
2628 		   EXT4_DESC_PER_BLOCK(sb);
2629 	sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
2630 				    GFP_KERNEL);
2631 	if (sbi->s_group_desc == NULL) {
2632 		ext4_msg(sb, KERN_ERR, "not enough memory");
2633 		goto failed_mount;
2634 	}
2635 
2636 #ifdef CONFIG_PROC_FS
2637 	if (ext4_proc_root)
2638 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
2639 #endif
2640 
2641 	bgl_lock_init(sbi->s_blockgroup_lock);
2642 
2643 	for (i = 0; i < db_count; i++) {
2644 		block = descriptor_loc(sb, logical_sb_block, i);
2645 		sbi->s_group_desc[i] = sb_bread(sb, block);
2646 		if (!sbi->s_group_desc[i]) {
2647 			ext4_msg(sb, KERN_ERR,
2648 			       "can't read group descriptor %d", i);
2649 			db_count = i;
2650 			goto failed_mount2;
2651 		}
2652 	}
2653 	if (!ext4_check_descriptors(sb)) {
2654 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
2655 		goto failed_mount2;
2656 	}
2657 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2658 		if (!ext4_fill_flex_info(sb)) {
2659 			ext4_msg(sb, KERN_ERR,
2660 			       "unable to initialize "
2661 			       "flex_bg meta info!");
2662 			goto failed_mount2;
2663 		}
2664 
2665 	sbi->s_gdb_count = db_count;
2666 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
2667 	spin_lock_init(&sbi->s_next_gen_lock);
2668 
2669 	err = percpu_counter_init(&sbi->s_freeblocks_counter,
2670 			ext4_count_free_blocks(sb));
2671 	if (!err) {
2672 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
2673 				ext4_count_free_inodes(sb));
2674 	}
2675 	if (!err) {
2676 		err = percpu_counter_init(&sbi->s_dirs_counter,
2677 				ext4_count_dirs(sb));
2678 	}
2679 	if (!err) {
2680 		err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
2681 	}
2682 	if (err) {
2683 		ext4_msg(sb, KERN_ERR, "insufficient memory");
2684 		goto failed_mount3;
2685 	}
2686 
2687 	sbi->s_stripe = ext4_get_stripe_size(sbi);
2688 	sbi->s_max_writeback_mb_bump = 128;
2689 
2690 	/*
2691 	 * set up enough so that it can read an inode
2692 	 */
2693 	if (!test_opt(sb, NOLOAD) &&
2694 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
2695 		sb->s_op = &ext4_sops;
2696 	else
2697 		sb->s_op = &ext4_nojournal_sops;
2698 	sb->s_export_op = &ext4_export_ops;
2699 	sb->s_xattr = ext4_xattr_handlers;
2700 #ifdef CONFIG_QUOTA
2701 	sb->s_qcop = &ext4_qctl_operations;
2702 	sb->dq_op = &ext4_quota_operations;
2703 #endif
2704 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
2705 	mutex_init(&sbi->s_orphan_lock);
2706 	mutex_init(&sbi->s_resize_lock);
2707 
2708 	sb->s_root = NULL;
2709 
2710 	needs_recovery = (es->s_last_orphan != 0 ||
2711 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
2712 				    EXT4_FEATURE_INCOMPAT_RECOVER));
2713 
2714 	/*
2715 	 * The first inode we look at is the journal inode.  Don't try
2716 	 * root first: it may be modified in the journal!
2717 	 */
2718 	if (!test_opt(sb, NOLOAD) &&
2719 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
2720 		if (ext4_load_journal(sb, es, journal_devnum))
2721 			goto failed_mount3;
2722 		if (!(sb->s_flags & MS_RDONLY) &&
2723 		    EXT4_SB(sb)->s_journal->j_failed_commit) {
2724 			ext4_msg(sb, KERN_CRIT, "error: "
2725 			       "ext4_fill_super: Journal transaction "
2726 			       "%u is corrupt",
2727 			       EXT4_SB(sb)->s_journal->j_failed_commit);
2728 			if (test_opt(sb, ERRORS_RO)) {
2729 				ext4_msg(sb, KERN_CRIT,
2730 				       "Mounting filesystem read-only");
2731 				sb->s_flags |= MS_RDONLY;
2732 				EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2733 				es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2734 			}
2735 			if (test_opt(sb, ERRORS_PANIC)) {
2736 				EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
2737 				es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
2738 				ext4_commit_super(sb, 1);
2739 				goto failed_mount4;
2740 			}
2741 		}
2742 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
2743 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
2744 		ext4_msg(sb, KERN_ERR, "required journal recovery "
2745 		       "suppressed and not mounted read-only");
2746 		goto failed_mount4;
2747 	} else {
2748 		clear_opt(sbi->s_mount_opt, DATA_FLAGS);
2749 		set_opt(sbi->s_mount_opt, WRITEBACK_DATA);
2750 		sbi->s_journal = NULL;
2751 		needs_recovery = 0;
2752 		goto no_journal;
2753 	}
2754 
2755 	if (ext4_blocks_count(es) > 0xffffffffULL &&
2756 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
2757 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
2758 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
2759 		goto failed_mount4;
2760 	}
2761 
2762 	jbd2_journal_set_features(sbi->s_journal,
2763 				  JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
2764 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
2765 		jbd2_journal_set_features(sbi->s_journal, 0, 0,
2766 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2767 	else
2768 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2769 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2770 
2771 	/* We have now updated the journal if required, so we can
2772 	 * validate the data journaling mode. */
2773 	switch (test_opt(sb, DATA_FLAGS)) {
2774 	case 0:
2775 		/* No mode set, assume a default based on the journal
2776 		 * capabilities: ORDERED_DATA if the journal can
2777 		 * cope, else JOURNAL_DATA
2778 		 */
2779 		if (jbd2_journal_check_available_features
2780 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
2781 			set_opt(sbi->s_mount_opt, ORDERED_DATA);
2782 		else
2783 			set_opt(sbi->s_mount_opt, JOURNAL_DATA);
2784 		break;
2785 
2786 	case EXT4_MOUNT_ORDERED_DATA:
2787 	case EXT4_MOUNT_WRITEBACK_DATA:
2788 		if (!jbd2_journal_check_available_features
2789 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
2790 			ext4_msg(sb, KERN_ERR, "Journal does not support "
2791 			       "requested data journaling mode");
2792 			goto failed_mount4;
2793 		}
2794 	default:
2795 		break;
2796 	}
2797 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
2798 
2799 no_journal:
2800 
2801 	if (test_opt(sb, NOBH)) {
2802 		if (!(test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)) {
2803 			ext4_msg(sb, KERN_WARNING, "Ignoring nobh option - "
2804 				"its supported only with writeback mode");
2805 			clear_opt(sbi->s_mount_opt, NOBH);
2806 		}
2807 	}
2808 	EXT4_SB(sb)->dio_unwritten_wq = create_workqueue("ext4-dio-unwritten");
2809 	if (!EXT4_SB(sb)->dio_unwritten_wq) {
2810 		printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
2811 		goto failed_mount_wq;
2812 	}
2813 
2814 	/*
2815 	 * The jbd2_journal_load will have done any necessary log recovery,
2816 	 * so we can safely mount the rest of the filesystem now.
2817 	 */
2818 
2819 	root = ext4_iget(sb, EXT4_ROOT_INO);
2820 	if (IS_ERR(root)) {
2821 		ext4_msg(sb, KERN_ERR, "get root inode failed");
2822 		ret = PTR_ERR(root);
2823 		goto failed_mount4;
2824 	}
2825 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
2826 		iput(root);
2827 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
2828 		goto failed_mount4;
2829 	}
2830 	sb->s_root = d_alloc_root(root);
2831 	if (!sb->s_root) {
2832 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
2833 		iput(root);
2834 		ret = -ENOMEM;
2835 		goto failed_mount4;
2836 	}
2837 
2838 	ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
2839 
2840 	/* determine the minimum size of new large inodes, if present */
2841 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
2842 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2843 						     EXT4_GOOD_OLD_INODE_SIZE;
2844 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
2845 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
2846 			if (sbi->s_want_extra_isize <
2847 			    le16_to_cpu(es->s_want_extra_isize))
2848 				sbi->s_want_extra_isize =
2849 					le16_to_cpu(es->s_want_extra_isize);
2850 			if (sbi->s_want_extra_isize <
2851 			    le16_to_cpu(es->s_min_extra_isize))
2852 				sbi->s_want_extra_isize =
2853 					le16_to_cpu(es->s_min_extra_isize);
2854 		}
2855 	}
2856 	/* Check if enough inode space is available */
2857 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
2858 							sbi->s_inode_size) {
2859 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
2860 						       EXT4_GOOD_OLD_INODE_SIZE;
2861 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
2862 			 "available");
2863 	}
2864 
2865 	if (test_opt(sb, DELALLOC) &&
2866 	    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2867 		ext4_msg(sb, KERN_WARNING, "Ignoring delalloc option - "
2868 			 "requested data journaling mode");
2869 		clear_opt(sbi->s_mount_opt, DELALLOC);
2870 	}
2871 
2872 	err = ext4_setup_system_zone(sb);
2873 	if (err) {
2874 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
2875 			 "zone (%d)\n", err);
2876 		goto failed_mount4;
2877 	}
2878 
2879 	ext4_ext_init(sb);
2880 	err = ext4_mb_init(sb, needs_recovery);
2881 	if (err) {
2882 		ext4_msg(sb, KERN_ERR, "failed to initalize mballoc (%d)",
2883 			 err);
2884 		goto failed_mount4;
2885 	}
2886 
2887 	sbi->s_kobj.kset = ext4_kset;
2888 	init_completion(&sbi->s_kobj_unregister);
2889 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
2890 				   "%s", sb->s_id);
2891 	if (err) {
2892 		ext4_mb_release(sb);
2893 		ext4_ext_release(sb);
2894 		goto failed_mount4;
2895 	};
2896 
2897 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
2898 	ext4_orphan_cleanup(sb, es);
2899 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
2900 	if (needs_recovery) {
2901 		ext4_msg(sb, KERN_INFO, "recovery complete");
2902 		ext4_mark_recovery_complete(sb, es);
2903 	}
2904 	if (EXT4_SB(sb)->s_journal) {
2905 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2906 			descr = " journalled data mode";
2907 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2908 			descr = " ordered data mode";
2909 		else
2910 			descr = " writeback data mode";
2911 	} else
2912 		descr = "out journal";
2913 
2914 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s", descr);
2915 
2916 	lock_kernel();
2917 	return 0;
2918 
2919 cantfind_ext4:
2920 	if (!silent)
2921 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
2922 	goto failed_mount;
2923 
2924 failed_mount4:
2925 	ext4_msg(sb, KERN_ERR, "mount failed");
2926 	destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
2927 failed_mount_wq:
2928 	ext4_release_system_zone(sb);
2929 	if (sbi->s_journal) {
2930 		jbd2_journal_destroy(sbi->s_journal);
2931 		sbi->s_journal = NULL;
2932 	}
2933 failed_mount3:
2934 	if (sbi->s_flex_groups) {
2935 		if (is_vmalloc_addr(sbi->s_flex_groups))
2936 			vfree(sbi->s_flex_groups);
2937 		else
2938 			kfree(sbi->s_flex_groups);
2939 	}
2940 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
2941 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
2942 	percpu_counter_destroy(&sbi->s_dirs_counter);
2943 	percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
2944 failed_mount2:
2945 	for (i = 0; i < db_count; i++)
2946 		brelse(sbi->s_group_desc[i]);
2947 	kfree(sbi->s_group_desc);
2948 failed_mount:
2949 	if (sbi->s_proc) {
2950 		remove_proc_entry(sb->s_id, ext4_proc_root);
2951 	}
2952 #ifdef CONFIG_QUOTA
2953 	for (i = 0; i < MAXQUOTAS; i++)
2954 		kfree(sbi->s_qf_names[i]);
2955 #endif
2956 	ext4_blkdev_remove(sbi);
2957 	brelse(bh);
2958 out_fail:
2959 	sb->s_fs_info = NULL;
2960 	kfree(sbi->s_blockgroup_lock);
2961 	kfree(sbi);
2962 	lock_kernel();
2963 	return ret;
2964 }
2965 
2966 /*
2967  * Setup any per-fs journal parameters now.  We'll do this both on
2968  * initial mount, once the journal has been initialised but before we've
2969  * done any recovery; and again on any subsequent remount.
2970  */
2971 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
2972 {
2973 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2974 
2975 	journal->j_commit_interval = sbi->s_commit_interval;
2976 	journal->j_min_batch_time = sbi->s_min_batch_time;
2977 	journal->j_max_batch_time = sbi->s_max_batch_time;
2978 
2979 	spin_lock(&journal->j_state_lock);
2980 	if (test_opt(sb, BARRIER))
2981 		journal->j_flags |= JBD2_BARRIER;
2982 	else
2983 		journal->j_flags &= ~JBD2_BARRIER;
2984 	if (test_opt(sb, DATA_ERR_ABORT))
2985 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
2986 	else
2987 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
2988 	spin_unlock(&journal->j_state_lock);
2989 }
2990 
2991 static journal_t *ext4_get_journal(struct super_block *sb,
2992 				   unsigned int journal_inum)
2993 {
2994 	struct inode *journal_inode;
2995 	journal_t *journal;
2996 
2997 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
2998 
2999 	/* First, test for the existence of a valid inode on disk.  Bad
3000 	 * things happen if we iget() an unused inode, as the subsequent
3001 	 * iput() will try to delete it. */
3002 
3003 	journal_inode = ext4_iget(sb, journal_inum);
3004 	if (IS_ERR(journal_inode)) {
3005 		ext4_msg(sb, KERN_ERR, "no journal found");
3006 		return NULL;
3007 	}
3008 	if (!journal_inode->i_nlink) {
3009 		make_bad_inode(journal_inode);
3010 		iput(journal_inode);
3011 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3012 		return NULL;
3013 	}
3014 
3015 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3016 		  journal_inode, journal_inode->i_size);
3017 	if (!S_ISREG(journal_inode->i_mode)) {
3018 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
3019 		iput(journal_inode);
3020 		return NULL;
3021 	}
3022 
3023 	journal = jbd2_journal_init_inode(journal_inode);
3024 	if (!journal) {
3025 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3026 		iput(journal_inode);
3027 		return NULL;
3028 	}
3029 	journal->j_private = sb;
3030 	ext4_init_journal_params(sb, journal);
3031 	return journal;
3032 }
3033 
3034 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3035 				       dev_t j_dev)
3036 {
3037 	struct buffer_head *bh;
3038 	journal_t *journal;
3039 	ext4_fsblk_t start;
3040 	ext4_fsblk_t len;
3041 	int hblock, blocksize;
3042 	ext4_fsblk_t sb_block;
3043 	unsigned long offset;
3044 	struct ext4_super_block *es;
3045 	struct block_device *bdev;
3046 
3047 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3048 
3049 	bdev = ext4_blkdev_get(j_dev, sb);
3050 	if (bdev == NULL)
3051 		return NULL;
3052 
3053 	if (bd_claim(bdev, sb)) {
3054 		ext4_msg(sb, KERN_ERR,
3055 			"failed to claim external journal device");
3056 		blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
3057 		return NULL;
3058 	}
3059 
3060 	blocksize = sb->s_blocksize;
3061 	hblock = bdev_logical_block_size(bdev);
3062 	if (blocksize < hblock) {
3063 		ext4_msg(sb, KERN_ERR,
3064 			"blocksize too small for journal device");
3065 		goto out_bdev;
3066 	}
3067 
3068 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3069 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3070 	set_blocksize(bdev, blocksize);
3071 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
3072 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3073 		       "external journal");
3074 		goto out_bdev;
3075 	}
3076 
3077 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3078 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3079 	    !(le32_to_cpu(es->s_feature_incompat) &
3080 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3081 		ext4_msg(sb, KERN_ERR, "external journal has "
3082 					"bad superblock");
3083 		brelse(bh);
3084 		goto out_bdev;
3085 	}
3086 
3087 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3088 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3089 		brelse(bh);
3090 		goto out_bdev;
3091 	}
3092 
3093 	len = ext4_blocks_count(es);
3094 	start = sb_block + 1;
3095 	brelse(bh);	/* we're done with the superblock */
3096 
3097 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3098 					start, len, blocksize);
3099 	if (!journal) {
3100 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
3101 		goto out_bdev;
3102 	}
3103 	journal->j_private = sb;
3104 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
3105 	wait_on_buffer(journal->j_sb_buffer);
3106 	if (!buffer_uptodate(journal->j_sb_buffer)) {
3107 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3108 		goto out_journal;
3109 	}
3110 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3111 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
3112 					"user (unsupported) - %d",
3113 			be32_to_cpu(journal->j_superblock->s_nr_users));
3114 		goto out_journal;
3115 	}
3116 	EXT4_SB(sb)->journal_bdev = bdev;
3117 	ext4_init_journal_params(sb, journal);
3118 	return journal;
3119 
3120 out_journal:
3121 	jbd2_journal_destroy(journal);
3122 out_bdev:
3123 	ext4_blkdev_put(bdev);
3124 	return NULL;
3125 }
3126 
3127 static int ext4_load_journal(struct super_block *sb,
3128 			     struct ext4_super_block *es,
3129 			     unsigned long journal_devnum)
3130 {
3131 	journal_t *journal;
3132 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3133 	dev_t journal_dev;
3134 	int err = 0;
3135 	int really_read_only;
3136 
3137 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3138 
3139 	if (journal_devnum &&
3140 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3141 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3142 			"numbers have changed");
3143 		journal_dev = new_decode_dev(journal_devnum);
3144 	} else
3145 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3146 
3147 	really_read_only = bdev_read_only(sb->s_bdev);
3148 
3149 	/*
3150 	 * Are we loading a blank journal or performing recovery after a
3151 	 * crash?  For recovery, we need to check in advance whether we
3152 	 * can get read-write access to the device.
3153 	 */
3154 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3155 		if (sb->s_flags & MS_RDONLY) {
3156 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
3157 					"required on readonly filesystem");
3158 			if (really_read_only) {
3159 				ext4_msg(sb, KERN_ERR, "write access "
3160 					"unavailable, cannot proceed");
3161 				return -EROFS;
3162 			}
3163 			ext4_msg(sb, KERN_INFO, "write access will "
3164 			       "be enabled during recovery");
3165 		}
3166 	}
3167 
3168 	if (journal_inum && journal_dev) {
3169 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3170 		       "and inode journals!");
3171 		return -EINVAL;
3172 	}
3173 
3174 	if (journal_inum) {
3175 		if (!(journal = ext4_get_journal(sb, journal_inum)))
3176 			return -EINVAL;
3177 	} else {
3178 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3179 			return -EINVAL;
3180 	}
3181 
3182 	if (!(journal->j_flags & JBD2_BARRIER))
3183 		ext4_msg(sb, KERN_INFO, "barriers disabled");
3184 
3185 	if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
3186 		err = jbd2_journal_update_format(journal);
3187 		if (err)  {
3188 			ext4_msg(sb, KERN_ERR, "error updating journal");
3189 			jbd2_journal_destroy(journal);
3190 			return err;
3191 		}
3192 	}
3193 
3194 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3195 		err = jbd2_journal_wipe(journal, !really_read_only);
3196 	if (!err)
3197 		err = jbd2_journal_load(journal);
3198 
3199 	if (err) {
3200 		ext4_msg(sb, KERN_ERR, "error loading journal");
3201 		jbd2_journal_destroy(journal);
3202 		return err;
3203 	}
3204 
3205 	EXT4_SB(sb)->s_journal = journal;
3206 	ext4_clear_journal_err(sb, es);
3207 
3208 	if (journal_devnum &&
3209 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3210 		es->s_journal_dev = cpu_to_le32(journal_devnum);
3211 
3212 		/* Make sure we flush the recovery flag to disk. */
3213 		ext4_commit_super(sb, 1);
3214 	}
3215 
3216 	return 0;
3217 }
3218 
3219 static int ext4_commit_super(struct super_block *sb, int sync)
3220 {
3221 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
3222 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3223 	int error = 0;
3224 
3225 	if (!sbh)
3226 		return error;
3227 	if (buffer_write_io_error(sbh)) {
3228 		/*
3229 		 * Oh, dear.  A previous attempt to write the
3230 		 * superblock failed.  This could happen because the
3231 		 * USB device was yanked out.  Or it could happen to
3232 		 * be a transient write error and maybe the block will
3233 		 * be remapped.  Nothing we can do but to retry the
3234 		 * write and hope for the best.
3235 		 */
3236 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
3237 		       "superblock detected");
3238 		clear_buffer_write_io_error(sbh);
3239 		set_buffer_uptodate(sbh);
3240 	}
3241 	/*
3242 	 * If the file system is mounted read-only, don't update the
3243 	 * superblock write time.  This avoids updating the superblock
3244 	 * write time when we are mounting the root file system
3245 	 * read/only but we need to replay the journal; at that point,
3246 	 * for people who are east of GMT and who make their clock
3247 	 * tick in localtime for Windows bug-for-bug compatibility,
3248 	 * the clock is set in the future, and this will cause e2fsck
3249 	 * to complain and force a full file system check.
3250 	 */
3251 	if (!(sb->s_flags & MS_RDONLY))
3252 		es->s_wtime = cpu_to_le32(get_seconds());
3253 	es->s_kbytes_written =
3254 		cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
3255 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
3256 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
3257 	ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
3258 					&EXT4_SB(sb)->s_freeblocks_counter));
3259 	es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(
3260 					&EXT4_SB(sb)->s_freeinodes_counter));
3261 	sb->s_dirt = 0;
3262 	BUFFER_TRACE(sbh, "marking dirty");
3263 	mark_buffer_dirty(sbh);
3264 	if (sync) {
3265 		error = sync_dirty_buffer(sbh);
3266 		if (error)
3267 			return error;
3268 
3269 		error = buffer_write_io_error(sbh);
3270 		if (error) {
3271 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
3272 			       "superblock");
3273 			clear_buffer_write_io_error(sbh);
3274 			set_buffer_uptodate(sbh);
3275 		}
3276 	}
3277 	return error;
3278 }
3279 
3280 /*
3281  * Have we just finished recovery?  If so, and if we are mounting (or
3282  * remounting) the filesystem readonly, then we will end up with a
3283  * consistent fs on disk.  Record that fact.
3284  */
3285 static void ext4_mark_recovery_complete(struct super_block *sb,
3286 					struct ext4_super_block *es)
3287 {
3288 	journal_t *journal = EXT4_SB(sb)->s_journal;
3289 
3290 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3291 		BUG_ON(journal != NULL);
3292 		return;
3293 	}
3294 	jbd2_journal_lock_updates(journal);
3295 	if (jbd2_journal_flush(journal) < 0)
3296 		goto out;
3297 
3298 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
3299 	    sb->s_flags & MS_RDONLY) {
3300 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3301 		ext4_commit_super(sb, 1);
3302 	}
3303 
3304 out:
3305 	jbd2_journal_unlock_updates(journal);
3306 }
3307 
3308 /*
3309  * If we are mounting (or read-write remounting) a filesystem whose journal
3310  * has recorded an error from a previous lifetime, move that error to the
3311  * main filesystem now.
3312  */
3313 static void ext4_clear_journal_err(struct super_block *sb,
3314 				   struct ext4_super_block *es)
3315 {
3316 	journal_t *journal;
3317 	int j_errno;
3318 	const char *errstr;
3319 
3320 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3321 
3322 	journal = EXT4_SB(sb)->s_journal;
3323 
3324 	/*
3325 	 * Now check for any error status which may have been recorded in the
3326 	 * journal by a prior ext4_error() or ext4_abort()
3327 	 */
3328 
3329 	j_errno = jbd2_journal_errno(journal);
3330 	if (j_errno) {
3331 		char nbuf[16];
3332 
3333 		errstr = ext4_decode_error(sb, j_errno, nbuf);
3334 		ext4_warning(sb, __func__, "Filesystem error recorded "
3335 			     "from previous mount: %s", errstr);
3336 		ext4_warning(sb, __func__, "Marking fs in need of "
3337 			     "filesystem check.");
3338 
3339 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
3340 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
3341 		ext4_commit_super(sb, 1);
3342 
3343 		jbd2_journal_clear_err(journal);
3344 	}
3345 }
3346 
3347 /*
3348  * Force the running and committing transactions to commit,
3349  * and wait on the commit.
3350  */
3351 int ext4_force_commit(struct super_block *sb)
3352 {
3353 	journal_t *journal;
3354 	int ret = 0;
3355 
3356 	if (sb->s_flags & MS_RDONLY)
3357 		return 0;
3358 
3359 	journal = EXT4_SB(sb)->s_journal;
3360 	if (journal)
3361 		ret = ext4_journal_force_commit(journal);
3362 
3363 	return ret;
3364 }
3365 
3366 static void ext4_write_super(struct super_block *sb)
3367 {
3368 	lock_super(sb);
3369 	ext4_commit_super(sb, 1);
3370 	unlock_super(sb);
3371 }
3372 
3373 static int ext4_sync_fs(struct super_block *sb, int wait)
3374 {
3375 	int ret = 0;
3376 	tid_t target;
3377 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3378 
3379 	trace_ext4_sync_fs(sb, wait);
3380 	flush_workqueue(sbi->dio_unwritten_wq);
3381 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
3382 		if (wait)
3383 			jbd2_log_wait_commit(sbi->s_journal, target);
3384 	}
3385 	return ret;
3386 }
3387 
3388 /*
3389  * LVM calls this function before a (read-only) snapshot is created.  This
3390  * gives us a chance to flush the journal completely and mark the fs clean.
3391  */
3392 static int ext4_freeze(struct super_block *sb)
3393 {
3394 	int error = 0;
3395 	journal_t *journal;
3396 
3397 	if (sb->s_flags & MS_RDONLY)
3398 		return 0;
3399 
3400 	journal = EXT4_SB(sb)->s_journal;
3401 
3402 	/* Now we set up the journal barrier. */
3403 	jbd2_journal_lock_updates(journal);
3404 
3405 	/*
3406 	 * Don't clear the needs_recovery flag if we failed to flush
3407 	 * the journal.
3408 	 */
3409 	error = jbd2_journal_flush(journal);
3410 	if (error < 0) {
3411 	out:
3412 		jbd2_journal_unlock_updates(journal);
3413 		return error;
3414 	}
3415 
3416 	/* Journal blocked and flushed, clear needs_recovery flag. */
3417 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3418 	error = ext4_commit_super(sb, 1);
3419 	if (error)
3420 		goto out;
3421 	return 0;
3422 }
3423 
3424 /*
3425  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
3426  * flag here, even though the filesystem is not technically dirty yet.
3427  */
3428 static int ext4_unfreeze(struct super_block *sb)
3429 {
3430 	if (sb->s_flags & MS_RDONLY)
3431 		return 0;
3432 
3433 	lock_super(sb);
3434 	/* Reset the needs_recovery flag before the fs is unlocked. */
3435 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
3436 	ext4_commit_super(sb, 1);
3437 	unlock_super(sb);
3438 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3439 	return 0;
3440 }
3441 
3442 static int ext4_remount(struct super_block *sb, int *flags, char *data)
3443 {
3444 	struct ext4_super_block *es;
3445 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3446 	ext4_fsblk_t n_blocks_count = 0;
3447 	unsigned long old_sb_flags;
3448 	struct ext4_mount_options old_opts;
3449 	ext4_group_t g;
3450 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3451 	int err;
3452 #ifdef CONFIG_QUOTA
3453 	int i;
3454 #endif
3455 
3456 	lock_kernel();
3457 
3458 	/* Store the original options */
3459 	lock_super(sb);
3460 	old_sb_flags = sb->s_flags;
3461 	old_opts.s_mount_opt = sbi->s_mount_opt;
3462 	old_opts.s_resuid = sbi->s_resuid;
3463 	old_opts.s_resgid = sbi->s_resgid;
3464 	old_opts.s_commit_interval = sbi->s_commit_interval;
3465 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
3466 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
3467 #ifdef CONFIG_QUOTA
3468 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
3469 	for (i = 0; i < MAXQUOTAS; i++)
3470 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
3471 #endif
3472 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
3473 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
3474 
3475 	/*
3476 	 * Allow the "check" option to be passed as a remount option.
3477 	 */
3478 	if (!parse_options(data, sb, NULL, &journal_ioprio,
3479 			   &n_blocks_count, 1)) {
3480 		err = -EINVAL;
3481 		goto restore_opts;
3482 	}
3483 
3484 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
3485 		ext4_abort(sb, __func__, "Abort forced by user");
3486 
3487 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3488 		((sbi->s_mount_opt & EXT4_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
3489 
3490 	es = sbi->s_es;
3491 
3492 	if (sbi->s_journal) {
3493 		ext4_init_journal_params(sb, sbi->s_journal);
3494 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3495 	}
3496 
3497 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
3498 		n_blocks_count > ext4_blocks_count(es)) {
3499 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
3500 			err = -EROFS;
3501 			goto restore_opts;
3502 		}
3503 
3504 		if (*flags & MS_RDONLY) {
3505 			/*
3506 			 * First of all, the unconditional stuff we have to do
3507 			 * to disable replay of the journal when we next remount
3508 			 */
3509 			sb->s_flags |= MS_RDONLY;
3510 
3511 			/*
3512 			 * OK, test if we are remounting a valid rw partition
3513 			 * readonly, and if so set the rdonly flag and then
3514 			 * mark the partition as valid again.
3515 			 */
3516 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
3517 			    (sbi->s_mount_state & EXT4_VALID_FS))
3518 				es->s_state = cpu_to_le16(sbi->s_mount_state);
3519 
3520 			if (sbi->s_journal)
3521 				ext4_mark_recovery_complete(sb, es);
3522 		} else {
3523 			/* Make sure we can mount this feature set readwrite */
3524 			if (!ext4_feature_set_ok(sb, 0)) {
3525 				err = -EROFS;
3526 				goto restore_opts;
3527 			}
3528 			/*
3529 			 * Make sure the group descriptor checksums
3530 			 * are sane.  If they aren't, refuse to remount r/w.
3531 			 */
3532 			for (g = 0; g < sbi->s_groups_count; g++) {
3533 				struct ext4_group_desc *gdp =
3534 					ext4_get_group_desc(sb, g, NULL);
3535 
3536 				if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
3537 					ext4_msg(sb, KERN_ERR,
3538 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
3539 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
3540 					       le16_to_cpu(gdp->bg_checksum));
3541 					err = -EINVAL;
3542 					goto restore_opts;
3543 				}
3544 			}
3545 
3546 			/*
3547 			 * If we have an unprocessed orphan list hanging
3548 			 * around from a previously readonly bdev mount,
3549 			 * require a full umount/remount for now.
3550 			 */
3551 			if (es->s_last_orphan) {
3552 				ext4_msg(sb, KERN_WARNING, "Couldn't "
3553 				       "remount RDWR because of unprocessed "
3554 				       "orphan inode list.  Please "
3555 				       "umount/remount instead");
3556 				err = -EINVAL;
3557 				goto restore_opts;
3558 			}
3559 
3560 			/*
3561 			 * Mounting a RDONLY partition read-write, so reread
3562 			 * and store the current valid flag.  (It may have
3563 			 * been changed by e2fsck since we originally mounted
3564 			 * the partition.)
3565 			 */
3566 			if (sbi->s_journal)
3567 				ext4_clear_journal_err(sb, es);
3568 			sbi->s_mount_state = le16_to_cpu(es->s_state);
3569 			if ((err = ext4_group_extend(sb, es, n_blocks_count)))
3570 				goto restore_opts;
3571 			if (!ext4_setup_super(sb, es, 0))
3572 				sb->s_flags &= ~MS_RDONLY;
3573 		}
3574 	}
3575 	ext4_setup_system_zone(sb);
3576 	if (sbi->s_journal == NULL)
3577 		ext4_commit_super(sb, 1);
3578 
3579 #ifdef CONFIG_QUOTA
3580 	/* Release old quota file names */
3581 	for (i = 0; i < MAXQUOTAS; i++)
3582 		if (old_opts.s_qf_names[i] &&
3583 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3584 			kfree(old_opts.s_qf_names[i]);
3585 #endif
3586 	unlock_super(sb);
3587 	unlock_kernel();
3588 	return 0;
3589 
3590 restore_opts:
3591 	sb->s_flags = old_sb_flags;
3592 	sbi->s_mount_opt = old_opts.s_mount_opt;
3593 	sbi->s_resuid = old_opts.s_resuid;
3594 	sbi->s_resgid = old_opts.s_resgid;
3595 	sbi->s_commit_interval = old_opts.s_commit_interval;
3596 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
3597 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
3598 #ifdef CONFIG_QUOTA
3599 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
3600 	for (i = 0; i < MAXQUOTAS; i++) {
3601 		if (sbi->s_qf_names[i] &&
3602 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
3603 			kfree(sbi->s_qf_names[i]);
3604 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
3605 	}
3606 #endif
3607 	unlock_super(sb);
3608 	unlock_kernel();
3609 	return err;
3610 }
3611 
3612 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
3613 {
3614 	struct super_block *sb = dentry->d_sb;
3615 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3616 	struct ext4_super_block *es = sbi->s_es;
3617 	u64 fsid;
3618 
3619 	if (test_opt(sb, MINIX_DF)) {
3620 		sbi->s_overhead_last = 0;
3621 	} else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
3622 		ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3623 		ext4_fsblk_t overhead = 0;
3624 
3625 		/*
3626 		 * Compute the overhead (FS structures).  This is constant
3627 		 * for a given filesystem unless the number of block groups
3628 		 * changes so we cache the previous value until it does.
3629 		 */
3630 
3631 		/*
3632 		 * All of the blocks before first_data_block are
3633 		 * overhead
3634 		 */
3635 		overhead = le32_to_cpu(es->s_first_data_block);
3636 
3637 		/*
3638 		 * Add the overhead attributed to the superblock and
3639 		 * block group descriptors.  If the sparse superblocks
3640 		 * feature is turned on, then not all groups have this.
3641 		 */
3642 		for (i = 0; i < ngroups; i++) {
3643 			overhead += ext4_bg_has_super(sb, i) +
3644 				ext4_bg_num_gdb(sb, i);
3645 			cond_resched();
3646 		}
3647 
3648 		/*
3649 		 * Every block group has an inode bitmap, a block
3650 		 * bitmap, and an inode table.
3651 		 */
3652 		overhead += ngroups * (2 + sbi->s_itb_per_group);
3653 		sbi->s_overhead_last = overhead;
3654 		smp_wmb();
3655 		sbi->s_blocks_last = ext4_blocks_count(es);
3656 	}
3657 
3658 	buf->f_type = EXT4_SUPER_MAGIC;
3659 	buf->f_bsize = sb->s_blocksize;
3660 	buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
3661 	buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
3662 		       percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
3663 	ext4_free_blocks_count_set(es, buf->f_bfree);
3664 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
3665 	if (buf->f_bfree < ext4_r_blocks_count(es))
3666 		buf->f_bavail = 0;
3667 	buf->f_files = le32_to_cpu(es->s_inodes_count);
3668 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
3669 	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
3670 	buf->f_namelen = EXT4_NAME_LEN;
3671 	fsid = le64_to_cpup((void *)es->s_uuid) ^
3672 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
3673 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
3674 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
3675 
3676 	return 0;
3677 }
3678 
3679 /* Helper function for writing quotas on sync - we need to start transaction
3680  * before quota file is locked for write. Otherwise the are possible deadlocks:
3681  * Process 1                         Process 2
3682  * ext4_create()                     quota_sync()
3683  *   jbd2_journal_start()                  write_dquot()
3684  *   vfs_dq_init()                         down(dqio_mutex)
3685  *     down(dqio_mutex)                    jbd2_journal_start()
3686  *
3687  */
3688 
3689 #ifdef CONFIG_QUOTA
3690 
3691 static inline struct inode *dquot_to_inode(struct dquot *dquot)
3692 {
3693 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
3694 }
3695 
3696 static int ext4_write_dquot(struct dquot *dquot)
3697 {
3698 	int ret, err;
3699 	handle_t *handle;
3700 	struct inode *inode;
3701 
3702 	inode = dquot_to_inode(dquot);
3703 	handle = ext4_journal_start(inode,
3704 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
3705 	if (IS_ERR(handle))
3706 		return PTR_ERR(handle);
3707 	ret = dquot_commit(dquot);
3708 	err = ext4_journal_stop(handle);
3709 	if (!ret)
3710 		ret = err;
3711 	return ret;
3712 }
3713 
3714 static int ext4_acquire_dquot(struct dquot *dquot)
3715 {
3716 	int ret, err;
3717 	handle_t *handle;
3718 
3719 	handle = ext4_journal_start(dquot_to_inode(dquot),
3720 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
3721 	if (IS_ERR(handle))
3722 		return PTR_ERR(handle);
3723 	ret = dquot_acquire(dquot);
3724 	err = ext4_journal_stop(handle);
3725 	if (!ret)
3726 		ret = err;
3727 	return ret;
3728 }
3729 
3730 static int ext4_release_dquot(struct dquot *dquot)
3731 {
3732 	int ret, err;
3733 	handle_t *handle;
3734 
3735 	handle = ext4_journal_start(dquot_to_inode(dquot),
3736 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
3737 	if (IS_ERR(handle)) {
3738 		/* Release dquot anyway to avoid endless cycle in dqput() */
3739 		dquot_release(dquot);
3740 		return PTR_ERR(handle);
3741 	}
3742 	ret = dquot_release(dquot);
3743 	err = ext4_journal_stop(handle);
3744 	if (!ret)
3745 		ret = err;
3746 	return ret;
3747 }
3748 
3749 static int ext4_mark_dquot_dirty(struct dquot *dquot)
3750 {
3751 	/* Are we journaling quotas? */
3752 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
3753 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
3754 		dquot_mark_dquot_dirty(dquot);
3755 		return ext4_write_dquot(dquot);
3756 	} else {
3757 		return dquot_mark_dquot_dirty(dquot);
3758 	}
3759 }
3760 
3761 static int ext4_write_info(struct super_block *sb, int type)
3762 {
3763 	int ret, err;
3764 	handle_t *handle;
3765 
3766 	/* Data block + inode block */
3767 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
3768 	if (IS_ERR(handle))
3769 		return PTR_ERR(handle);
3770 	ret = dquot_commit_info(sb, type);
3771 	err = ext4_journal_stop(handle);
3772 	if (!ret)
3773 		ret = err;
3774 	return ret;
3775 }
3776 
3777 /*
3778  * Turn on quotas during mount time - we need to find
3779  * the quota file and such...
3780  */
3781 static int ext4_quota_on_mount(struct super_block *sb, int type)
3782 {
3783 	return vfs_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
3784 				  EXT4_SB(sb)->s_jquota_fmt, type);
3785 }
3786 
3787 /*
3788  * Standard function to be called on quota_on
3789  */
3790 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
3791 			 char *name, int remount)
3792 {
3793 	int err;
3794 	struct path path;
3795 
3796 	if (!test_opt(sb, QUOTA))
3797 		return -EINVAL;
3798 	/* When remounting, no checks are needed and in fact, name is NULL */
3799 	if (remount)
3800 		return vfs_quota_on(sb, type, format_id, name, remount);
3801 
3802 	err = kern_path(name, LOOKUP_FOLLOW, &path);
3803 	if (err)
3804 		return err;
3805 
3806 	/* Quotafile not on the same filesystem? */
3807 	if (path.mnt->mnt_sb != sb) {
3808 		path_put(&path);
3809 		return -EXDEV;
3810 	}
3811 	/* Journaling quota? */
3812 	if (EXT4_SB(sb)->s_qf_names[type]) {
3813 		/* Quotafile not in fs root? */
3814 		if (path.dentry->d_parent != sb->s_root)
3815 			ext4_msg(sb, KERN_WARNING,
3816 				"Quota file not on filesystem root. "
3817 				"Journaled quota will not work");
3818 	}
3819 
3820 	/*
3821 	 * When we journal data on quota file, we have to flush journal to see
3822 	 * all updates to the file when we bypass pagecache...
3823 	 */
3824 	if (EXT4_SB(sb)->s_journal &&
3825 	    ext4_should_journal_data(path.dentry->d_inode)) {
3826 		/*
3827 		 * We don't need to lock updates but journal_flush() could
3828 		 * otherwise be livelocked...
3829 		 */
3830 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
3831 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
3832 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
3833 		if (err) {
3834 			path_put(&path);
3835 			return err;
3836 		}
3837 	}
3838 
3839 	err = vfs_quota_on_path(sb, type, format_id, &path);
3840 	path_put(&path);
3841 	return err;
3842 }
3843 
3844 /* Read data from quotafile - avoid pagecache and such because we cannot afford
3845  * acquiring the locks... As quota files are never truncated and quota code
3846  * itself serializes the operations (and noone else should touch the files)
3847  * we don't have to be afraid of races */
3848 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
3849 			       size_t len, loff_t off)
3850 {
3851 	struct inode *inode = sb_dqopt(sb)->files[type];
3852 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3853 	int err = 0;
3854 	int offset = off & (sb->s_blocksize - 1);
3855 	int tocopy;
3856 	size_t toread;
3857 	struct buffer_head *bh;
3858 	loff_t i_size = i_size_read(inode);
3859 
3860 	if (off > i_size)
3861 		return 0;
3862 	if (off+len > i_size)
3863 		len = i_size-off;
3864 	toread = len;
3865 	while (toread > 0) {
3866 		tocopy = sb->s_blocksize - offset < toread ?
3867 				sb->s_blocksize - offset : toread;
3868 		bh = ext4_bread(NULL, inode, blk, 0, &err);
3869 		if (err)
3870 			return err;
3871 		if (!bh)	/* A hole? */
3872 			memset(data, 0, tocopy);
3873 		else
3874 			memcpy(data, bh->b_data+offset, tocopy);
3875 		brelse(bh);
3876 		offset = 0;
3877 		toread -= tocopy;
3878 		data += tocopy;
3879 		blk++;
3880 	}
3881 	return len;
3882 }
3883 
3884 /* Write to quotafile (we know the transaction is already started and has
3885  * enough credits) */
3886 static ssize_t ext4_quota_write(struct super_block *sb, int type,
3887 				const char *data, size_t len, loff_t off)
3888 {
3889 	struct inode *inode = sb_dqopt(sb)->files[type];
3890 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
3891 	int err = 0;
3892 	int offset = off & (sb->s_blocksize - 1);
3893 	int tocopy;
3894 	int journal_quota = EXT4_SB(sb)->s_qf_names[type] != NULL;
3895 	size_t towrite = len;
3896 	struct buffer_head *bh;
3897 	handle_t *handle = journal_current_handle();
3898 
3899 	if (EXT4_SB(sb)->s_journal && !handle) {
3900 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
3901 			" cancelled because transaction is not started",
3902 			(unsigned long long)off, (unsigned long long)len);
3903 		return -EIO;
3904 	}
3905 	mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
3906 	while (towrite > 0) {
3907 		tocopy = sb->s_blocksize - offset < towrite ?
3908 				sb->s_blocksize - offset : towrite;
3909 		bh = ext4_bread(handle, inode, blk, 1, &err);
3910 		if (!bh)
3911 			goto out;
3912 		if (journal_quota) {
3913 			err = ext4_journal_get_write_access(handle, bh);
3914 			if (err) {
3915 				brelse(bh);
3916 				goto out;
3917 			}
3918 		}
3919 		lock_buffer(bh);
3920 		memcpy(bh->b_data+offset, data, tocopy);
3921 		flush_dcache_page(bh->b_page);
3922 		unlock_buffer(bh);
3923 		if (journal_quota)
3924 			err = ext4_handle_dirty_metadata(handle, NULL, bh);
3925 		else {
3926 			/* Always do at least ordered writes for quotas */
3927 			err = ext4_jbd2_file_inode(handle, inode);
3928 			mark_buffer_dirty(bh);
3929 		}
3930 		brelse(bh);
3931 		if (err)
3932 			goto out;
3933 		offset = 0;
3934 		towrite -= tocopy;
3935 		data += tocopy;
3936 		blk++;
3937 	}
3938 out:
3939 	if (len == towrite) {
3940 		mutex_unlock(&inode->i_mutex);
3941 		return err;
3942 	}
3943 	if (inode->i_size < off+len-towrite) {
3944 		i_size_write(inode, off+len-towrite);
3945 		EXT4_I(inode)->i_disksize = inode->i_size;
3946 	}
3947 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3948 	ext4_mark_inode_dirty(handle, inode);
3949 	mutex_unlock(&inode->i_mutex);
3950 	return len - towrite;
3951 }
3952 
3953 #endif
3954 
3955 static int ext4_get_sb(struct file_system_type *fs_type, int flags,
3956 		       const char *dev_name, void *data, struct vfsmount *mnt)
3957 {
3958 	return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super,mnt);
3959 }
3960 
3961 static struct file_system_type ext4_fs_type = {
3962 	.owner		= THIS_MODULE,
3963 	.name		= "ext4",
3964 	.get_sb		= ext4_get_sb,
3965 	.kill_sb	= kill_block_super,
3966 	.fs_flags	= FS_REQUIRES_DEV,
3967 };
3968 
3969 static int __init init_ext4_fs(void)
3970 {
3971 	int err;
3972 
3973 	err = init_ext4_system_zone();
3974 	if (err)
3975 		return err;
3976 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
3977 	if (!ext4_kset)
3978 		goto out4;
3979 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
3980 	err = init_ext4_mballoc();
3981 	if (err)
3982 		goto out3;
3983 
3984 	err = init_ext4_xattr();
3985 	if (err)
3986 		goto out2;
3987 	err = init_inodecache();
3988 	if (err)
3989 		goto out1;
3990 	err = register_filesystem(&ext4_fs_type);
3991 	if (err)
3992 		goto out;
3993 	return 0;
3994 out:
3995 	destroy_inodecache();
3996 out1:
3997 	exit_ext4_xattr();
3998 out2:
3999 	exit_ext4_mballoc();
4000 out3:
4001 	remove_proc_entry("fs/ext4", NULL);
4002 	kset_unregister(ext4_kset);
4003 out4:
4004 	exit_ext4_system_zone();
4005 	return err;
4006 }
4007 
4008 static void __exit exit_ext4_fs(void)
4009 {
4010 	unregister_filesystem(&ext4_fs_type);
4011 	destroy_inodecache();
4012 	exit_ext4_xattr();
4013 	exit_ext4_mballoc();
4014 	remove_proc_entry("fs/ext4", NULL);
4015 	kset_unregister(ext4_kset);
4016 	exit_ext4_system_zone();
4017 }
4018 
4019 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
4020 MODULE_DESCRIPTION("Fourth Extended Filesystem");
4021 MODULE_LICENSE("GPL");
4022 module_init(init_ext4_fs)
4023 module_exit(exit_ext4_fs)
4024