xref: /linux/fs/ext4/super.c (revision a67ff6a54095e27093ea501fb143fefe51a536c2)
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/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/proc_fs.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/cleancache.h>
42 #include <asm/uaccess.h>
43 
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46 
47 #include "ext4.h"
48 #include "ext4_extents.h"
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/ext4.h>
56 
57 static struct proc_dir_entry *ext4_proc_root;
58 static struct kset *ext4_kset;
59 static struct ext4_lazy_init *ext4_li_info;
60 static struct mutex ext4_li_mtx;
61 static struct ext4_features *ext4_feat;
62 
63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
64 			     unsigned long journal_devnum);
65 static int ext4_commit_super(struct super_block *sb, int sync);
66 static void ext4_mark_recovery_complete(struct super_block *sb,
67 					struct ext4_super_block *es);
68 static void ext4_clear_journal_err(struct super_block *sb,
69 				   struct ext4_super_block *es);
70 static int ext4_sync_fs(struct super_block *sb, int wait);
71 static const char *ext4_decode_error(struct super_block *sb, int errno,
72 				     char nbuf[16]);
73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
75 static int ext4_unfreeze(struct super_block *sb);
76 static void ext4_write_super(struct super_block *sb);
77 static int ext4_freeze(struct super_block *sb);
78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
79 		       const char *dev_name, void *data);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
83 static void ext4_destroy_lazyinit_thread(void);
84 static void ext4_unregister_li_request(struct super_block *sb);
85 static void ext4_clear_request_list(void);
86 
87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
88 static struct file_system_type ext2_fs_type = {
89 	.owner		= THIS_MODULE,
90 	.name		= "ext2",
91 	.mount		= ext4_mount,
92 	.kill_sb	= kill_block_super,
93 	.fs_flags	= FS_REQUIRES_DEV,
94 };
95 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
96 #else
97 #define IS_EXT2_SB(sb) (0)
98 #endif
99 
100 
101 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
102 static struct file_system_type ext3_fs_type = {
103 	.owner		= THIS_MODULE,
104 	.name		= "ext3",
105 	.mount		= ext4_mount,
106 	.kill_sb	= kill_block_super,
107 	.fs_flags	= FS_REQUIRES_DEV,
108 };
109 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
110 #else
111 #define IS_EXT3_SB(sb) (0)
112 #endif
113 
114 void *ext4_kvmalloc(size_t size, gfp_t flags)
115 {
116 	void *ret;
117 
118 	ret = kmalloc(size, flags);
119 	if (!ret)
120 		ret = __vmalloc(size, flags, PAGE_KERNEL);
121 	return ret;
122 }
123 
124 void *ext4_kvzalloc(size_t size, gfp_t flags)
125 {
126 	void *ret;
127 
128 	ret = kzalloc(size, flags);
129 	if (!ret)
130 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
131 	return ret;
132 }
133 
134 void ext4_kvfree(void *ptr)
135 {
136 	if (is_vmalloc_addr(ptr))
137 		vfree(ptr);
138 	else
139 		kfree(ptr);
140 
141 }
142 
143 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
144 			       struct ext4_group_desc *bg)
145 {
146 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
147 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
148 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
149 }
150 
151 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
152 			       struct ext4_group_desc *bg)
153 {
154 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
155 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
156 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
157 }
158 
159 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
160 			      struct ext4_group_desc *bg)
161 {
162 	return le32_to_cpu(bg->bg_inode_table_lo) |
163 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
164 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
165 }
166 
167 __u32 ext4_free_group_clusters(struct super_block *sb,
168 			       struct ext4_group_desc *bg)
169 {
170 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
171 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
172 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
173 }
174 
175 __u32 ext4_free_inodes_count(struct super_block *sb,
176 			      struct ext4_group_desc *bg)
177 {
178 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
179 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
180 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
181 }
182 
183 __u32 ext4_used_dirs_count(struct super_block *sb,
184 			      struct ext4_group_desc *bg)
185 {
186 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
187 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
188 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
189 }
190 
191 __u32 ext4_itable_unused_count(struct super_block *sb,
192 			      struct ext4_group_desc *bg)
193 {
194 	return le16_to_cpu(bg->bg_itable_unused_lo) |
195 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
196 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
197 }
198 
199 void ext4_block_bitmap_set(struct super_block *sb,
200 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
201 {
202 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
203 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
204 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
205 }
206 
207 void ext4_inode_bitmap_set(struct super_block *sb,
208 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
209 {
210 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
211 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
212 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
213 }
214 
215 void ext4_inode_table_set(struct super_block *sb,
216 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
217 {
218 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
219 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
220 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
221 }
222 
223 void ext4_free_group_clusters_set(struct super_block *sb,
224 				  struct ext4_group_desc *bg, __u32 count)
225 {
226 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
227 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
228 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
229 }
230 
231 void ext4_free_inodes_set(struct super_block *sb,
232 			  struct ext4_group_desc *bg, __u32 count)
233 {
234 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
235 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
236 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
237 }
238 
239 void ext4_used_dirs_set(struct super_block *sb,
240 			  struct ext4_group_desc *bg, __u32 count)
241 {
242 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
243 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
244 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
245 }
246 
247 void ext4_itable_unused_set(struct super_block *sb,
248 			  struct ext4_group_desc *bg, __u32 count)
249 {
250 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
251 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
252 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
253 }
254 
255 
256 /* Just increment the non-pointer handle value */
257 static handle_t *ext4_get_nojournal(void)
258 {
259 	handle_t *handle = current->journal_info;
260 	unsigned long ref_cnt = (unsigned long)handle;
261 
262 	BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
263 
264 	ref_cnt++;
265 	handle = (handle_t *)ref_cnt;
266 
267 	current->journal_info = handle;
268 	return handle;
269 }
270 
271 
272 /* Decrement the non-pointer handle value */
273 static void ext4_put_nojournal(handle_t *handle)
274 {
275 	unsigned long ref_cnt = (unsigned long)handle;
276 
277 	BUG_ON(ref_cnt == 0);
278 
279 	ref_cnt--;
280 	handle = (handle_t *)ref_cnt;
281 
282 	current->journal_info = handle;
283 }
284 
285 /*
286  * Wrappers for jbd2_journal_start/end.
287  *
288  * The only special thing we need to do here is to make sure that all
289  * journal_end calls result in the superblock being marked dirty, so
290  * that sync() will call the filesystem's write_super callback if
291  * appropriate.
292  *
293  * To avoid j_barrier hold in userspace when a user calls freeze(),
294  * ext4 prevents a new handle from being started by s_frozen, which
295  * is in an upper layer.
296  */
297 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
298 {
299 	journal_t *journal;
300 	handle_t  *handle;
301 
302 	trace_ext4_journal_start(sb, nblocks, _RET_IP_);
303 	if (sb->s_flags & MS_RDONLY)
304 		return ERR_PTR(-EROFS);
305 
306 	journal = EXT4_SB(sb)->s_journal;
307 	handle = ext4_journal_current_handle();
308 
309 	/*
310 	 * If a handle has been started, it should be allowed to
311 	 * finish, otherwise deadlock could happen between freeze
312 	 * and others(e.g. truncate) due to the restart of the
313 	 * journal handle if the filesystem is forzen and active
314 	 * handles are not stopped.
315 	 */
316 	if (!handle)
317 		vfs_check_frozen(sb, SB_FREEZE_TRANS);
318 
319 	if (!journal)
320 		return ext4_get_nojournal();
321 	/*
322 	 * Special case here: if the journal has aborted behind our
323 	 * backs (eg. EIO in the commit thread), then we still need to
324 	 * take the FS itself readonly cleanly.
325 	 */
326 	if (is_journal_aborted(journal)) {
327 		ext4_abort(sb, "Detected aborted journal");
328 		return ERR_PTR(-EROFS);
329 	}
330 	return jbd2_journal_start(journal, nblocks);
331 }
332 
333 /*
334  * The only special thing we need to do here is to make sure that all
335  * jbd2_journal_stop calls result in the superblock being marked dirty, so
336  * that sync() will call the filesystem's write_super callback if
337  * appropriate.
338  */
339 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
340 {
341 	struct super_block *sb;
342 	int err;
343 	int rc;
344 
345 	if (!ext4_handle_valid(handle)) {
346 		ext4_put_nojournal(handle);
347 		return 0;
348 	}
349 	sb = handle->h_transaction->t_journal->j_private;
350 	err = handle->h_err;
351 	rc = jbd2_journal_stop(handle);
352 
353 	if (!err)
354 		err = rc;
355 	if (err)
356 		__ext4_std_error(sb, where, line, err);
357 	return err;
358 }
359 
360 void ext4_journal_abort_handle(const char *caller, unsigned int line,
361 			       const char *err_fn, struct buffer_head *bh,
362 			       handle_t *handle, int err)
363 {
364 	char nbuf[16];
365 	const char *errstr = ext4_decode_error(NULL, err, nbuf);
366 
367 	BUG_ON(!ext4_handle_valid(handle));
368 
369 	if (bh)
370 		BUFFER_TRACE(bh, "abort");
371 
372 	if (!handle->h_err)
373 		handle->h_err = err;
374 
375 	if (is_handle_aborted(handle))
376 		return;
377 
378 	printk(KERN_ERR "%s:%d: aborting transaction: %s in %s\n",
379 	       caller, line, errstr, err_fn);
380 
381 	jbd2_journal_abort_handle(handle);
382 }
383 
384 static void __save_error_info(struct super_block *sb, const char *func,
385 			    unsigned int line)
386 {
387 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
388 
389 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
390 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
391 	es->s_last_error_time = cpu_to_le32(get_seconds());
392 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
393 	es->s_last_error_line = cpu_to_le32(line);
394 	if (!es->s_first_error_time) {
395 		es->s_first_error_time = es->s_last_error_time;
396 		strncpy(es->s_first_error_func, func,
397 			sizeof(es->s_first_error_func));
398 		es->s_first_error_line = cpu_to_le32(line);
399 		es->s_first_error_ino = es->s_last_error_ino;
400 		es->s_first_error_block = es->s_last_error_block;
401 	}
402 	/*
403 	 * Start the daily error reporting function if it hasn't been
404 	 * started already
405 	 */
406 	if (!es->s_error_count)
407 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
408 	es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
409 }
410 
411 static void save_error_info(struct super_block *sb, const char *func,
412 			    unsigned int line)
413 {
414 	__save_error_info(sb, func, line);
415 	ext4_commit_super(sb, 1);
416 }
417 
418 /*
419  * The del_gendisk() function uninitializes the disk-specific data
420  * structures, including the bdi structure, without telling anyone
421  * else.  Once this happens, any attempt to call mark_buffer_dirty()
422  * (for example, by ext4_commit_super), will cause a kernel OOPS.
423  * This is a kludge to prevent these oops until we can put in a proper
424  * hook in del_gendisk() to inform the VFS and file system layers.
425  */
426 static int block_device_ejected(struct super_block *sb)
427 {
428 	struct inode *bd_inode = sb->s_bdev->bd_inode;
429 	struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
430 
431 	return bdi->dev == NULL;
432 }
433 
434 
435 /* Deal with the reporting of failure conditions on a filesystem such as
436  * inconsistencies detected or read IO failures.
437  *
438  * On ext2, we can store the error state of the filesystem in the
439  * superblock.  That is not possible on ext4, because we may have other
440  * write ordering constraints on the superblock which prevent us from
441  * writing it out straight away; and given that the journal is about to
442  * be aborted, we can't rely on the current, or future, transactions to
443  * write out the superblock safely.
444  *
445  * We'll just use the jbd2_journal_abort() error code to record an error in
446  * the journal instead.  On recovery, the journal will complain about
447  * that error until we've noted it down and cleared it.
448  */
449 
450 static void ext4_handle_error(struct super_block *sb)
451 {
452 	if (sb->s_flags & MS_RDONLY)
453 		return;
454 
455 	if (!test_opt(sb, ERRORS_CONT)) {
456 		journal_t *journal = EXT4_SB(sb)->s_journal;
457 
458 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
459 		if (journal)
460 			jbd2_journal_abort(journal, -EIO);
461 	}
462 	if (test_opt(sb, ERRORS_RO)) {
463 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
464 		sb->s_flags |= MS_RDONLY;
465 	}
466 	if (test_opt(sb, ERRORS_PANIC))
467 		panic("EXT4-fs (device %s): panic forced after error\n",
468 			sb->s_id);
469 }
470 
471 void __ext4_error(struct super_block *sb, const char *function,
472 		  unsigned int line, const char *fmt, ...)
473 {
474 	struct va_format vaf;
475 	va_list args;
476 
477 	va_start(args, fmt);
478 	vaf.fmt = fmt;
479 	vaf.va = &args;
480 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
481 	       sb->s_id, function, line, current->comm, &vaf);
482 	va_end(args);
483 
484 	ext4_handle_error(sb);
485 }
486 
487 void ext4_error_inode(struct inode *inode, const char *function,
488 		      unsigned int line, ext4_fsblk_t block,
489 		      const char *fmt, ...)
490 {
491 	va_list args;
492 	struct va_format vaf;
493 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
494 
495 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
496 	es->s_last_error_block = cpu_to_le64(block);
497 	save_error_info(inode->i_sb, function, line);
498 	va_start(args, fmt);
499 	vaf.fmt = fmt;
500 	vaf.va = &args;
501 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
502 	       inode->i_sb->s_id, function, line, inode->i_ino);
503 	if (block)
504 		printk(KERN_CONT "block %llu: ", block);
505 	printk(KERN_CONT "comm %s: %pV\n", current->comm, &vaf);
506 	va_end(args);
507 
508 	ext4_handle_error(inode->i_sb);
509 }
510 
511 void ext4_error_file(struct file *file, const char *function,
512 		     unsigned int line, ext4_fsblk_t block,
513 		     const char *fmt, ...)
514 {
515 	va_list args;
516 	struct va_format vaf;
517 	struct ext4_super_block *es;
518 	struct inode *inode = file->f_dentry->d_inode;
519 	char pathname[80], *path;
520 
521 	es = EXT4_SB(inode->i_sb)->s_es;
522 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
523 	save_error_info(inode->i_sb, function, line);
524 	path = d_path(&(file->f_path), pathname, sizeof(pathname));
525 	if (IS_ERR(path))
526 		path = "(unknown)";
527 	printk(KERN_CRIT
528 	       "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
529 	       inode->i_sb->s_id, function, line, inode->i_ino);
530 	if (block)
531 		printk(KERN_CONT "block %llu: ", block);
532 	va_start(args, fmt);
533 	vaf.fmt = fmt;
534 	vaf.va = &args;
535 	printk(KERN_CONT "comm %s: path %s: %pV\n", current->comm, path, &vaf);
536 	va_end(args);
537 
538 	ext4_handle_error(inode->i_sb);
539 }
540 
541 static const char *ext4_decode_error(struct super_block *sb, int errno,
542 				     char nbuf[16])
543 {
544 	char *errstr = NULL;
545 
546 	switch (errno) {
547 	case -EIO:
548 		errstr = "IO failure";
549 		break;
550 	case -ENOMEM:
551 		errstr = "Out of memory";
552 		break;
553 	case -EROFS:
554 		if (!sb || (EXT4_SB(sb)->s_journal &&
555 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
556 			errstr = "Journal has aborted";
557 		else
558 			errstr = "Readonly filesystem";
559 		break;
560 	default:
561 		/* If the caller passed in an extra buffer for unknown
562 		 * errors, textualise them now.  Else we just return
563 		 * NULL. */
564 		if (nbuf) {
565 			/* Check for truncated error codes... */
566 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
567 				errstr = nbuf;
568 		}
569 		break;
570 	}
571 
572 	return errstr;
573 }
574 
575 /* __ext4_std_error decodes expected errors from journaling functions
576  * automatically and invokes the appropriate error response.  */
577 
578 void __ext4_std_error(struct super_block *sb, const char *function,
579 		      unsigned int line, int errno)
580 {
581 	char nbuf[16];
582 	const char *errstr;
583 
584 	/* Special case: if the error is EROFS, and we're not already
585 	 * inside a transaction, then there's really no point in logging
586 	 * an error. */
587 	if (errno == -EROFS && journal_current_handle() == NULL &&
588 	    (sb->s_flags & MS_RDONLY))
589 		return;
590 
591 	errstr = ext4_decode_error(sb, errno, nbuf);
592 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
593 	       sb->s_id, function, line, errstr);
594 	save_error_info(sb, function, line);
595 
596 	ext4_handle_error(sb);
597 }
598 
599 /*
600  * ext4_abort is a much stronger failure handler than ext4_error.  The
601  * abort function may be used to deal with unrecoverable failures such
602  * as journal IO errors or ENOMEM at a critical moment in log management.
603  *
604  * We unconditionally force the filesystem into an ABORT|READONLY state,
605  * unless the error response on the fs has been set to panic in which
606  * case we take the easy way out and panic immediately.
607  */
608 
609 void __ext4_abort(struct super_block *sb, const char *function,
610 		unsigned int line, const char *fmt, ...)
611 {
612 	va_list args;
613 
614 	save_error_info(sb, function, line);
615 	va_start(args, fmt);
616 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
617 	       function, line);
618 	vprintk(fmt, args);
619 	printk("\n");
620 	va_end(args);
621 
622 	if ((sb->s_flags & MS_RDONLY) == 0) {
623 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
624 		sb->s_flags |= MS_RDONLY;
625 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
626 		if (EXT4_SB(sb)->s_journal)
627 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
628 		save_error_info(sb, function, line);
629 	}
630 	if (test_opt(sb, ERRORS_PANIC))
631 		panic("EXT4-fs panic from previous error\n");
632 }
633 
634 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
635 {
636 	struct va_format vaf;
637 	va_list args;
638 
639 	va_start(args, fmt);
640 	vaf.fmt = fmt;
641 	vaf.va = &args;
642 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
643 	va_end(args);
644 }
645 
646 void __ext4_warning(struct super_block *sb, const char *function,
647 		    unsigned int line, const char *fmt, ...)
648 {
649 	struct va_format vaf;
650 	va_list args;
651 
652 	va_start(args, fmt);
653 	vaf.fmt = fmt;
654 	vaf.va = &args;
655 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
656 	       sb->s_id, function, line, &vaf);
657 	va_end(args);
658 }
659 
660 void __ext4_grp_locked_error(const char *function, unsigned int line,
661 			     struct super_block *sb, ext4_group_t grp,
662 			     unsigned long ino, ext4_fsblk_t block,
663 			     const char *fmt, ...)
664 __releases(bitlock)
665 __acquires(bitlock)
666 {
667 	struct va_format vaf;
668 	va_list args;
669 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
670 
671 	es->s_last_error_ino = cpu_to_le32(ino);
672 	es->s_last_error_block = cpu_to_le64(block);
673 	__save_error_info(sb, function, line);
674 
675 	va_start(args, fmt);
676 
677 	vaf.fmt = fmt;
678 	vaf.va = &args;
679 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
680 	       sb->s_id, function, line, grp);
681 	if (ino)
682 		printk(KERN_CONT "inode %lu: ", ino);
683 	if (block)
684 		printk(KERN_CONT "block %llu:", (unsigned long long) block);
685 	printk(KERN_CONT "%pV\n", &vaf);
686 	va_end(args);
687 
688 	if (test_opt(sb, ERRORS_CONT)) {
689 		ext4_commit_super(sb, 0);
690 		return;
691 	}
692 
693 	ext4_unlock_group(sb, grp);
694 	ext4_handle_error(sb);
695 	/*
696 	 * We only get here in the ERRORS_RO case; relocking the group
697 	 * may be dangerous, but nothing bad will happen since the
698 	 * filesystem will have already been marked read/only and the
699 	 * journal has been aborted.  We return 1 as a hint to callers
700 	 * who might what to use the return value from
701 	 * ext4_grp_locked_error() to distinguish between the
702 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
703 	 * aggressively from the ext4 function in question, with a
704 	 * more appropriate error code.
705 	 */
706 	ext4_lock_group(sb, grp);
707 	return;
708 }
709 
710 void ext4_update_dynamic_rev(struct super_block *sb)
711 {
712 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
713 
714 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
715 		return;
716 
717 	ext4_warning(sb,
718 		     "updating to rev %d because of new feature flag, "
719 		     "running e2fsck is recommended",
720 		     EXT4_DYNAMIC_REV);
721 
722 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
723 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
724 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
725 	/* leave es->s_feature_*compat flags alone */
726 	/* es->s_uuid will be set by e2fsck if empty */
727 
728 	/*
729 	 * The rest of the superblock fields should be zero, and if not it
730 	 * means they are likely already in use, so leave them alone.  We
731 	 * can leave it up to e2fsck to clean up any inconsistencies there.
732 	 */
733 }
734 
735 /*
736  * Open the external journal device
737  */
738 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
739 {
740 	struct block_device *bdev;
741 	char b[BDEVNAME_SIZE];
742 
743 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
744 	if (IS_ERR(bdev))
745 		goto fail;
746 	return bdev;
747 
748 fail:
749 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
750 			__bdevname(dev, b), PTR_ERR(bdev));
751 	return NULL;
752 }
753 
754 /*
755  * Release the journal device
756  */
757 static int ext4_blkdev_put(struct block_device *bdev)
758 {
759 	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
760 }
761 
762 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
763 {
764 	struct block_device *bdev;
765 	int ret = -ENODEV;
766 
767 	bdev = sbi->journal_bdev;
768 	if (bdev) {
769 		ret = ext4_blkdev_put(bdev);
770 		sbi->journal_bdev = NULL;
771 	}
772 	return ret;
773 }
774 
775 static inline struct inode *orphan_list_entry(struct list_head *l)
776 {
777 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
778 }
779 
780 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
781 {
782 	struct list_head *l;
783 
784 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
785 		 le32_to_cpu(sbi->s_es->s_last_orphan));
786 
787 	printk(KERN_ERR "sb_info orphan list:\n");
788 	list_for_each(l, &sbi->s_orphan) {
789 		struct inode *inode = orphan_list_entry(l);
790 		printk(KERN_ERR "  "
791 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
792 		       inode->i_sb->s_id, inode->i_ino, inode,
793 		       inode->i_mode, inode->i_nlink,
794 		       NEXT_ORPHAN(inode));
795 	}
796 }
797 
798 static void ext4_put_super(struct super_block *sb)
799 {
800 	struct ext4_sb_info *sbi = EXT4_SB(sb);
801 	struct ext4_super_block *es = sbi->s_es;
802 	int i, err;
803 
804 	ext4_unregister_li_request(sb);
805 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
806 
807 	flush_workqueue(sbi->dio_unwritten_wq);
808 	destroy_workqueue(sbi->dio_unwritten_wq);
809 
810 	lock_super(sb);
811 	if (sb->s_dirt)
812 		ext4_commit_super(sb, 1);
813 
814 	if (sbi->s_journal) {
815 		err = jbd2_journal_destroy(sbi->s_journal);
816 		sbi->s_journal = NULL;
817 		if (err < 0)
818 			ext4_abort(sb, "Couldn't clean up the journal");
819 	}
820 
821 	del_timer(&sbi->s_err_report);
822 	ext4_release_system_zone(sb);
823 	ext4_mb_release(sb);
824 	ext4_ext_release(sb);
825 	ext4_xattr_put_super(sb);
826 
827 	if (!(sb->s_flags & MS_RDONLY)) {
828 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
829 		es->s_state = cpu_to_le16(sbi->s_mount_state);
830 		ext4_commit_super(sb, 1);
831 	}
832 	if (sbi->s_proc) {
833 		remove_proc_entry(sb->s_id, ext4_proc_root);
834 	}
835 	kobject_del(&sbi->s_kobj);
836 
837 	for (i = 0; i < sbi->s_gdb_count; i++)
838 		brelse(sbi->s_group_desc[i]);
839 	ext4_kvfree(sbi->s_group_desc);
840 	ext4_kvfree(sbi->s_flex_groups);
841 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
842 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
843 	percpu_counter_destroy(&sbi->s_dirs_counter);
844 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
845 	brelse(sbi->s_sbh);
846 #ifdef CONFIG_QUOTA
847 	for (i = 0; i < MAXQUOTAS; i++)
848 		kfree(sbi->s_qf_names[i]);
849 #endif
850 
851 	/* Debugging code just in case the in-memory inode orphan list
852 	 * isn't empty.  The on-disk one can be non-empty if we've
853 	 * detected an error and taken the fs readonly, but the
854 	 * in-memory list had better be clean by this point. */
855 	if (!list_empty(&sbi->s_orphan))
856 		dump_orphan_list(sb, sbi);
857 	J_ASSERT(list_empty(&sbi->s_orphan));
858 
859 	invalidate_bdev(sb->s_bdev);
860 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
861 		/*
862 		 * Invalidate the journal device's buffers.  We don't want them
863 		 * floating about in memory - the physical journal device may
864 		 * hotswapped, and it breaks the `ro-after' testing code.
865 		 */
866 		sync_blockdev(sbi->journal_bdev);
867 		invalidate_bdev(sbi->journal_bdev);
868 		ext4_blkdev_remove(sbi);
869 	}
870 	if (sbi->s_mmp_tsk)
871 		kthread_stop(sbi->s_mmp_tsk);
872 	sb->s_fs_info = NULL;
873 	/*
874 	 * Now that we are completely done shutting down the
875 	 * superblock, we need to actually destroy the kobject.
876 	 */
877 	unlock_super(sb);
878 	kobject_put(&sbi->s_kobj);
879 	wait_for_completion(&sbi->s_kobj_unregister);
880 	kfree(sbi->s_blockgroup_lock);
881 	kfree(sbi);
882 }
883 
884 static struct kmem_cache *ext4_inode_cachep;
885 
886 /*
887  * Called inside transaction, so use GFP_NOFS
888  */
889 static struct inode *ext4_alloc_inode(struct super_block *sb)
890 {
891 	struct ext4_inode_info *ei;
892 
893 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
894 	if (!ei)
895 		return NULL;
896 
897 	ei->vfs_inode.i_version = 1;
898 	ei->vfs_inode.i_data.writeback_index = 0;
899 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
900 	INIT_LIST_HEAD(&ei->i_prealloc_list);
901 	spin_lock_init(&ei->i_prealloc_lock);
902 	ei->i_reserved_data_blocks = 0;
903 	ei->i_reserved_meta_blocks = 0;
904 	ei->i_allocated_meta_blocks = 0;
905 	ei->i_da_metadata_calc_len = 0;
906 	spin_lock_init(&(ei->i_block_reservation_lock));
907 #ifdef CONFIG_QUOTA
908 	ei->i_reserved_quota = 0;
909 #endif
910 	ei->jinode = NULL;
911 	INIT_LIST_HEAD(&ei->i_completed_io_list);
912 	spin_lock_init(&ei->i_completed_io_lock);
913 	ei->cur_aio_dio = NULL;
914 	ei->i_sync_tid = 0;
915 	ei->i_datasync_tid = 0;
916 	atomic_set(&ei->i_ioend_count, 0);
917 	atomic_set(&ei->i_aiodio_unwritten, 0);
918 
919 	return &ei->vfs_inode;
920 }
921 
922 static int ext4_drop_inode(struct inode *inode)
923 {
924 	int drop = generic_drop_inode(inode);
925 
926 	trace_ext4_drop_inode(inode, drop);
927 	return drop;
928 }
929 
930 static void ext4_i_callback(struct rcu_head *head)
931 {
932 	struct inode *inode = container_of(head, struct inode, i_rcu);
933 	INIT_LIST_HEAD(&inode->i_dentry);
934 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
935 }
936 
937 static void ext4_destroy_inode(struct inode *inode)
938 {
939 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
940 		ext4_msg(inode->i_sb, KERN_ERR,
941 			 "Inode %lu (%p): orphan list check failed!",
942 			 inode->i_ino, EXT4_I(inode));
943 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
944 				EXT4_I(inode), sizeof(struct ext4_inode_info),
945 				true);
946 		dump_stack();
947 	}
948 	call_rcu(&inode->i_rcu, ext4_i_callback);
949 }
950 
951 static void init_once(void *foo)
952 {
953 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
954 
955 	INIT_LIST_HEAD(&ei->i_orphan);
956 #ifdef CONFIG_EXT4_FS_XATTR
957 	init_rwsem(&ei->xattr_sem);
958 #endif
959 	init_rwsem(&ei->i_data_sem);
960 	inode_init_once(&ei->vfs_inode);
961 }
962 
963 static int init_inodecache(void)
964 {
965 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
966 					     sizeof(struct ext4_inode_info),
967 					     0, (SLAB_RECLAIM_ACCOUNT|
968 						SLAB_MEM_SPREAD),
969 					     init_once);
970 	if (ext4_inode_cachep == NULL)
971 		return -ENOMEM;
972 	return 0;
973 }
974 
975 static void destroy_inodecache(void)
976 {
977 	kmem_cache_destroy(ext4_inode_cachep);
978 }
979 
980 void ext4_clear_inode(struct inode *inode)
981 {
982 	invalidate_inode_buffers(inode);
983 	end_writeback(inode);
984 	dquot_drop(inode);
985 	ext4_discard_preallocations(inode);
986 	if (EXT4_I(inode)->jinode) {
987 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
988 					       EXT4_I(inode)->jinode);
989 		jbd2_free_inode(EXT4_I(inode)->jinode);
990 		EXT4_I(inode)->jinode = NULL;
991 	}
992 }
993 
994 static inline void ext4_show_quota_options(struct seq_file *seq,
995 					   struct super_block *sb)
996 {
997 #if defined(CONFIG_QUOTA)
998 	struct ext4_sb_info *sbi = EXT4_SB(sb);
999 
1000 	if (sbi->s_jquota_fmt) {
1001 		char *fmtname = "";
1002 
1003 		switch (sbi->s_jquota_fmt) {
1004 		case QFMT_VFS_OLD:
1005 			fmtname = "vfsold";
1006 			break;
1007 		case QFMT_VFS_V0:
1008 			fmtname = "vfsv0";
1009 			break;
1010 		case QFMT_VFS_V1:
1011 			fmtname = "vfsv1";
1012 			break;
1013 		}
1014 		seq_printf(seq, ",jqfmt=%s", fmtname);
1015 	}
1016 
1017 	if (sbi->s_qf_names[USRQUOTA])
1018 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1019 
1020 	if (sbi->s_qf_names[GRPQUOTA])
1021 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1022 
1023 	if (test_opt(sb, USRQUOTA))
1024 		seq_puts(seq, ",usrquota");
1025 
1026 	if (test_opt(sb, GRPQUOTA))
1027 		seq_puts(seq, ",grpquota");
1028 #endif
1029 }
1030 
1031 /*
1032  * Show an option if
1033  *  - it's set to a non-default value OR
1034  *  - if the per-sb default is different from the global default
1035  */
1036 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
1037 {
1038 	int def_errors;
1039 	unsigned long def_mount_opts;
1040 	struct super_block *sb = vfs->mnt_sb;
1041 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1042 	struct ext4_super_block *es = sbi->s_es;
1043 
1044 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
1045 	def_errors     = le16_to_cpu(es->s_errors);
1046 
1047 	if (sbi->s_sb_block != 1)
1048 		seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
1049 	if (test_opt(sb, MINIX_DF))
1050 		seq_puts(seq, ",minixdf");
1051 	if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
1052 		seq_puts(seq, ",grpid");
1053 	if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
1054 		seq_puts(seq, ",nogrpid");
1055 	if (sbi->s_resuid != EXT4_DEF_RESUID ||
1056 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
1057 		seq_printf(seq, ",resuid=%u", sbi->s_resuid);
1058 	}
1059 	if (sbi->s_resgid != EXT4_DEF_RESGID ||
1060 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
1061 		seq_printf(seq, ",resgid=%u", sbi->s_resgid);
1062 	}
1063 	if (test_opt(sb, ERRORS_RO)) {
1064 		if (def_errors == EXT4_ERRORS_PANIC ||
1065 		    def_errors == EXT4_ERRORS_CONTINUE) {
1066 			seq_puts(seq, ",errors=remount-ro");
1067 		}
1068 	}
1069 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1070 		seq_puts(seq, ",errors=continue");
1071 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1072 		seq_puts(seq, ",errors=panic");
1073 	if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
1074 		seq_puts(seq, ",nouid32");
1075 	if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
1076 		seq_puts(seq, ",debug");
1077 #ifdef CONFIG_EXT4_FS_XATTR
1078 	if (test_opt(sb, XATTR_USER))
1079 		seq_puts(seq, ",user_xattr");
1080 	if (!test_opt(sb, XATTR_USER))
1081 		seq_puts(seq, ",nouser_xattr");
1082 #endif
1083 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1084 	if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
1085 		seq_puts(seq, ",acl");
1086 	if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
1087 		seq_puts(seq, ",noacl");
1088 #endif
1089 	if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
1090 		seq_printf(seq, ",commit=%u",
1091 			   (unsigned) (sbi->s_commit_interval / HZ));
1092 	}
1093 	if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
1094 		seq_printf(seq, ",min_batch_time=%u",
1095 			   (unsigned) sbi->s_min_batch_time);
1096 	}
1097 	if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
1098 		seq_printf(seq, ",max_batch_time=%u",
1099 			   (unsigned) sbi->s_min_batch_time);
1100 	}
1101 
1102 	/*
1103 	 * We're changing the default of barrier mount option, so
1104 	 * let's always display its mount state so it's clear what its
1105 	 * status is.
1106 	 */
1107 	seq_puts(seq, ",barrier=");
1108 	seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
1109 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
1110 		seq_puts(seq, ",journal_async_commit");
1111 	else if (test_opt(sb, JOURNAL_CHECKSUM))
1112 		seq_puts(seq, ",journal_checksum");
1113 	if (test_opt(sb, I_VERSION))
1114 		seq_puts(seq, ",i_version");
1115 	if (!test_opt(sb, DELALLOC) &&
1116 	    !(def_mount_opts & EXT4_DEFM_NODELALLOC))
1117 		seq_puts(seq, ",nodelalloc");
1118 
1119 	if (!test_opt(sb, MBLK_IO_SUBMIT))
1120 		seq_puts(seq, ",nomblk_io_submit");
1121 	if (sbi->s_stripe)
1122 		seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
1123 	/*
1124 	 * journal mode get enabled in different ways
1125 	 * So just print the value even if we didn't specify it
1126 	 */
1127 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1128 		seq_puts(seq, ",data=journal");
1129 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1130 		seq_puts(seq, ",data=ordered");
1131 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1132 		seq_puts(seq, ",data=writeback");
1133 
1134 	if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1135 		seq_printf(seq, ",inode_readahead_blks=%u",
1136 			   sbi->s_inode_readahead_blks);
1137 
1138 	if (test_opt(sb, DATA_ERR_ABORT))
1139 		seq_puts(seq, ",data_err=abort");
1140 
1141 	if (test_opt(sb, NO_AUTO_DA_ALLOC))
1142 		seq_puts(seq, ",noauto_da_alloc");
1143 
1144 	if (test_opt(sb, DISCARD) && !(def_mount_opts & EXT4_DEFM_DISCARD))
1145 		seq_puts(seq, ",discard");
1146 
1147 	if (test_opt(sb, NOLOAD))
1148 		seq_puts(seq, ",norecovery");
1149 
1150 	if (test_opt(sb, DIOREAD_NOLOCK))
1151 		seq_puts(seq, ",dioread_nolock");
1152 
1153 	if (test_opt(sb, BLOCK_VALIDITY) &&
1154 	    !(def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY))
1155 		seq_puts(seq, ",block_validity");
1156 
1157 	if (!test_opt(sb, INIT_INODE_TABLE))
1158 		seq_puts(seq, ",noinit_inode_table");
1159 	else if (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)
1160 		seq_printf(seq, ",init_inode_table=%u",
1161 			   (unsigned) sbi->s_li_wait_mult);
1162 
1163 	ext4_show_quota_options(seq, sb);
1164 
1165 	return 0;
1166 }
1167 
1168 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1169 					u64 ino, u32 generation)
1170 {
1171 	struct inode *inode;
1172 
1173 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1174 		return ERR_PTR(-ESTALE);
1175 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1176 		return ERR_PTR(-ESTALE);
1177 
1178 	/* iget isn't really right if the inode is currently unallocated!!
1179 	 *
1180 	 * ext4_read_inode will return a bad_inode if the inode had been
1181 	 * deleted, so we should be safe.
1182 	 *
1183 	 * Currently we don't know the generation for parent directory, so
1184 	 * a generation of 0 means "accept any"
1185 	 */
1186 	inode = ext4_iget(sb, ino);
1187 	if (IS_ERR(inode))
1188 		return ERR_CAST(inode);
1189 	if (generation && inode->i_generation != generation) {
1190 		iput(inode);
1191 		return ERR_PTR(-ESTALE);
1192 	}
1193 
1194 	return inode;
1195 }
1196 
1197 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1198 					int fh_len, int fh_type)
1199 {
1200 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1201 				    ext4_nfs_get_inode);
1202 }
1203 
1204 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1205 					int fh_len, int fh_type)
1206 {
1207 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1208 				    ext4_nfs_get_inode);
1209 }
1210 
1211 /*
1212  * Try to release metadata pages (indirect blocks, directories) which are
1213  * mapped via the block device.  Since these pages could have journal heads
1214  * which would prevent try_to_free_buffers() from freeing them, we must use
1215  * jbd2 layer's try_to_free_buffers() function to release them.
1216  */
1217 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1218 				 gfp_t wait)
1219 {
1220 	journal_t *journal = EXT4_SB(sb)->s_journal;
1221 
1222 	WARN_ON(PageChecked(page));
1223 	if (!page_has_buffers(page))
1224 		return 0;
1225 	if (journal)
1226 		return jbd2_journal_try_to_free_buffers(journal, page,
1227 							wait & ~__GFP_WAIT);
1228 	return try_to_free_buffers(page);
1229 }
1230 
1231 #ifdef CONFIG_QUOTA
1232 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1233 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1234 
1235 static int ext4_write_dquot(struct dquot *dquot);
1236 static int ext4_acquire_dquot(struct dquot *dquot);
1237 static int ext4_release_dquot(struct dquot *dquot);
1238 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1239 static int ext4_write_info(struct super_block *sb, int type);
1240 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1241 			 struct path *path);
1242 static int ext4_quota_off(struct super_block *sb, int type);
1243 static int ext4_quota_on_mount(struct super_block *sb, int type);
1244 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1245 			       size_t len, loff_t off);
1246 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1247 				const char *data, size_t len, loff_t off);
1248 
1249 static const struct dquot_operations ext4_quota_operations = {
1250 	.get_reserved_space = ext4_get_reserved_space,
1251 	.write_dquot	= ext4_write_dquot,
1252 	.acquire_dquot	= ext4_acquire_dquot,
1253 	.release_dquot	= ext4_release_dquot,
1254 	.mark_dirty	= ext4_mark_dquot_dirty,
1255 	.write_info	= ext4_write_info,
1256 	.alloc_dquot	= dquot_alloc,
1257 	.destroy_dquot	= dquot_destroy,
1258 };
1259 
1260 static const struct quotactl_ops ext4_qctl_operations = {
1261 	.quota_on	= ext4_quota_on,
1262 	.quota_off	= ext4_quota_off,
1263 	.quota_sync	= dquot_quota_sync,
1264 	.get_info	= dquot_get_dqinfo,
1265 	.set_info	= dquot_set_dqinfo,
1266 	.get_dqblk	= dquot_get_dqblk,
1267 	.set_dqblk	= dquot_set_dqblk
1268 };
1269 #endif
1270 
1271 static const struct super_operations ext4_sops = {
1272 	.alloc_inode	= ext4_alloc_inode,
1273 	.destroy_inode	= ext4_destroy_inode,
1274 	.write_inode	= ext4_write_inode,
1275 	.dirty_inode	= ext4_dirty_inode,
1276 	.drop_inode	= ext4_drop_inode,
1277 	.evict_inode	= ext4_evict_inode,
1278 	.put_super	= ext4_put_super,
1279 	.sync_fs	= ext4_sync_fs,
1280 	.freeze_fs	= ext4_freeze,
1281 	.unfreeze_fs	= ext4_unfreeze,
1282 	.statfs		= ext4_statfs,
1283 	.remount_fs	= ext4_remount,
1284 	.show_options	= ext4_show_options,
1285 #ifdef CONFIG_QUOTA
1286 	.quota_read	= ext4_quota_read,
1287 	.quota_write	= ext4_quota_write,
1288 #endif
1289 	.bdev_try_to_free_page = bdev_try_to_free_page,
1290 };
1291 
1292 static const struct super_operations ext4_nojournal_sops = {
1293 	.alloc_inode	= ext4_alloc_inode,
1294 	.destroy_inode	= ext4_destroy_inode,
1295 	.write_inode	= ext4_write_inode,
1296 	.dirty_inode	= ext4_dirty_inode,
1297 	.drop_inode	= ext4_drop_inode,
1298 	.evict_inode	= ext4_evict_inode,
1299 	.write_super	= ext4_write_super,
1300 	.put_super	= ext4_put_super,
1301 	.statfs		= ext4_statfs,
1302 	.remount_fs	= ext4_remount,
1303 	.show_options	= ext4_show_options,
1304 #ifdef CONFIG_QUOTA
1305 	.quota_read	= ext4_quota_read,
1306 	.quota_write	= ext4_quota_write,
1307 #endif
1308 	.bdev_try_to_free_page = bdev_try_to_free_page,
1309 };
1310 
1311 static const struct export_operations ext4_export_ops = {
1312 	.fh_to_dentry = ext4_fh_to_dentry,
1313 	.fh_to_parent = ext4_fh_to_parent,
1314 	.get_parent = ext4_get_parent,
1315 };
1316 
1317 enum {
1318 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1319 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1320 	Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1321 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1322 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1323 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1324 	Opt_journal_update, Opt_journal_dev,
1325 	Opt_journal_checksum, Opt_journal_async_commit,
1326 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1327 	Opt_data_err_abort, Opt_data_err_ignore,
1328 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1329 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1330 	Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err,
1331 	Opt_resize, Opt_usrquota, Opt_grpquota, Opt_i_version,
1332 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1333 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1334 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1335 	Opt_dioread_nolock, Opt_dioread_lock,
1336 	Opt_discard, Opt_nodiscard,
1337 	Opt_init_inode_table, Opt_noinit_inode_table,
1338 };
1339 
1340 static const match_table_t tokens = {
1341 	{Opt_bsd_df, "bsddf"},
1342 	{Opt_minix_df, "minixdf"},
1343 	{Opt_grpid, "grpid"},
1344 	{Opt_grpid, "bsdgroups"},
1345 	{Opt_nogrpid, "nogrpid"},
1346 	{Opt_nogrpid, "sysvgroups"},
1347 	{Opt_resgid, "resgid=%u"},
1348 	{Opt_resuid, "resuid=%u"},
1349 	{Opt_sb, "sb=%u"},
1350 	{Opt_err_cont, "errors=continue"},
1351 	{Opt_err_panic, "errors=panic"},
1352 	{Opt_err_ro, "errors=remount-ro"},
1353 	{Opt_nouid32, "nouid32"},
1354 	{Opt_debug, "debug"},
1355 	{Opt_oldalloc, "oldalloc"},
1356 	{Opt_orlov, "orlov"},
1357 	{Opt_user_xattr, "user_xattr"},
1358 	{Opt_nouser_xattr, "nouser_xattr"},
1359 	{Opt_acl, "acl"},
1360 	{Opt_noacl, "noacl"},
1361 	{Opt_noload, "noload"},
1362 	{Opt_noload, "norecovery"},
1363 	{Opt_nobh, "nobh"},
1364 	{Opt_bh, "bh"},
1365 	{Opt_commit, "commit=%u"},
1366 	{Opt_min_batch_time, "min_batch_time=%u"},
1367 	{Opt_max_batch_time, "max_batch_time=%u"},
1368 	{Opt_journal_update, "journal=update"},
1369 	{Opt_journal_dev, "journal_dev=%u"},
1370 	{Opt_journal_checksum, "journal_checksum"},
1371 	{Opt_journal_async_commit, "journal_async_commit"},
1372 	{Opt_abort, "abort"},
1373 	{Opt_data_journal, "data=journal"},
1374 	{Opt_data_ordered, "data=ordered"},
1375 	{Opt_data_writeback, "data=writeback"},
1376 	{Opt_data_err_abort, "data_err=abort"},
1377 	{Opt_data_err_ignore, "data_err=ignore"},
1378 	{Opt_offusrjquota, "usrjquota="},
1379 	{Opt_usrjquota, "usrjquota=%s"},
1380 	{Opt_offgrpjquota, "grpjquota="},
1381 	{Opt_grpjquota, "grpjquota=%s"},
1382 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1383 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1384 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1385 	{Opt_grpquota, "grpquota"},
1386 	{Opt_noquota, "noquota"},
1387 	{Opt_quota, "quota"},
1388 	{Opt_usrquota, "usrquota"},
1389 	{Opt_barrier, "barrier=%u"},
1390 	{Opt_barrier, "barrier"},
1391 	{Opt_nobarrier, "nobarrier"},
1392 	{Opt_i_version, "i_version"},
1393 	{Opt_stripe, "stripe=%u"},
1394 	{Opt_resize, "resize"},
1395 	{Opt_delalloc, "delalloc"},
1396 	{Opt_nodelalloc, "nodelalloc"},
1397 	{Opt_mblk_io_submit, "mblk_io_submit"},
1398 	{Opt_nomblk_io_submit, "nomblk_io_submit"},
1399 	{Opt_block_validity, "block_validity"},
1400 	{Opt_noblock_validity, "noblock_validity"},
1401 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1402 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1403 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1404 	{Opt_auto_da_alloc, "auto_da_alloc"},
1405 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1406 	{Opt_dioread_nolock, "dioread_nolock"},
1407 	{Opt_dioread_lock, "dioread_lock"},
1408 	{Opt_discard, "discard"},
1409 	{Opt_nodiscard, "nodiscard"},
1410 	{Opt_init_inode_table, "init_itable=%u"},
1411 	{Opt_init_inode_table, "init_itable"},
1412 	{Opt_noinit_inode_table, "noinit_itable"},
1413 	{Opt_err, NULL},
1414 };
1415 
1416 static ext4_fsblk_t get_sb_block(void **data)
1417 {
1418 	ext4_fsblk_t	sb_block;
1419 	char		*options = (char *) *data;
1420 
1421 	if (!options || strncmp(options, "sb=", 3) != 0)
1422 		return 1;	/* Default location */
1423 
1424 	options += 3;
1425 	/* TODO: use simple_strtoll with >32bit ext4 */
1426 	sb_block = simple_strtoul(options, &options, 0);
1427 	if (*options && *options != ',') {
1428 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1429 		       (char *) *data);
1430 		return 1;
1431 	}
1432 	if (*options == ',')
1433 		options++;
1434 	*data = (void *) options;
1435 
1436 	return sb_block;
1437 }
1438 
1439 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1440 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1441 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1442 
1443 #ifdef CONFIG_QUOTA
1444 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1445 {
1446 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1447 	char *qname;
1448 
1449 	if (sb_any_quota_loaded(sb) &&
1450 		!sbi->s_qf_names[qtype]) {
1451 		ext4_msg(sb, KERN_ERR,
1452 			"Cannot change journaled "
1453 			"quota options when quota turned on");
1454 		return 0;
1455 	}
1456 	qname = match_strdup(args);
1457 	if (!qname) {
1458 		ext4_msg(sb, KERN_ERR,
1459 			"Not enough memory for storing quotafile name");
1460 		return 0;
1461 	}
1462 	if (sbi->s_qf_names[qtype] &&
1463 		strcmp(sbi->s_qf_names[qtype], qname)) {
1464 		ext4_msg(sb, KERN_ERR,
1465 			"%s quota file already specified", QTYPE2NAME(qtype));
1466 		kfree(qname);
1467 		return 0;
1468 	}
1469 	sbi->s_qf_names[qtype] = qname;
1470 	if (strchr(sbi->s_qf_names[qtype], '/')) {
1471 		ext4_msg(sb, KERN_ERR,
1472 			"quotafile must be on filesystem root");
1473 		kfree(sbi->s_qf_names[qtype]);
1474 		sbi->s_qf_names[qtype] = NULL;
1475 		return 0;
1476 	}
1477 	set_opt(sb, QUOTA);
1478 	return 1;
1479 }
1480 
1481 static int clear_qf_name(struct super_block *sb, int qtype)
1482 {
1483 
1484 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1485 
1486 	if (sb_any_quota_loaded(sb) &&
1487 		sbi->s_qf_names[qtype]) {
1488 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1489 			" when quota turned on");
1490 		return 0;
1491 	}
1492 	/*
1493 	 * The space will be released later when all options are confirmed
1494 	 * to be correct
1495 	 */
1496 	sbi->s_qf_names[qtype] = NULL;
1497 	return 1;
1498 }
1499 #endif
1500 
1501 static int parse_options(char *options, struct super_block *sb,
1502 			 unsigned long *journal_devnum,
1503 			 unsigned int *journal_ioprio,
1504 			 ext4_fsblk_t *n_blocks_count, int is_remount)
1505 {
1506 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1507 	char *p;
1508 	substring_t args[MAX_OPT_ARGS];
1509 	int data_opt = 0;
1510 	int option;
1511 #ifdef CONFIG_QUOTA
1512 	int qfmt;
1513 #endif
1514 
1515 	if (!options)
1516 		return 1;
1517 
1518 	while ((p = strsep(&options, ",")) != NULL) {
1519 		int token;
1520 		if (!*p)
1521 			continue;
1522 
1523 		/*
1524 		 * Initialize args struct so we know whether arg was
1525 		 * found; some options take optional arguments.
1526 		 */
1527 		args[0].to = args[0].from = NULL;
1528 		token = match_token(p, tokens, args);
1529 		switch (token) {
1530 		case Opt_bsd_df:
1531 			ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1532 			clear_opt(sb, MINIX_DF);
1533 			break;
1534 		case Opt_minix_df:
1535 			ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1536 			set_opt(sb, MINIX_DF);
1537 
1538 			break;
1539 		case Opt_grpid:
1540 			ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1541 			set_opt(sb, GRPID);
1542 
1543 			break;
1544 		case Opt_nogrpid:
1545 			ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1546 			clear_opt(sb, GRPID);
1547 
1548 			break;
1549 		case Opt_resuid:
1550 			if (match_int(&args[0], &option))
1551 				return 0;
1552 			sbi->s_resuid = option;
1553 			break;
1554 		case Opt_resgid:
1555 			if (match_int(&args[0], &option))
1556 				return 0;
1557 			sbi->s_resgid = option;
1558 			break;
1559 		case Opt_sb:
1560 			/* handled by get_sb_block() instead of here */
1561 			/* *sb_block = match_int(&args[0]); */
1562 			break;
1563 		case Opt_err_panic:
1564 			clear_opt(sb, ERRORS_CONT);
1565 			clear_opt(sb, ERRORS_RO);
1566 			set_opt(sb, ERRORS_PANIC);
1567 			break;
1568 		case Opt_err_ro:
1569 			clear_opt(sb, ERRORS_CONT);
1570 			clear_opt(sb, ERRORS_PANIC);
1571 			set_opt(sb, ERRORS_RO);
1572 			break;
1573 		case Opt_err_cont:
1574 			clear_opt(sb, ERRORS_RO);
1575 			clear_opt(sb, ERRORS_PANIC);
1576 			set_opt(sb, ERRORS_CONT);
1577 			break;
1578 		case Opt_nouid32:
1579 			set_opt(sb, NO_UID32);
1580 			break;
1581 		case Opt_debug:
1582 			set_opt(sb, DEBUG);
1583 			break;
1584 		case Opt_oldalloc:
1585 			ext4_msg(sb, KERN_WARNING,
1586 				 "Ignoring deprecated oldalloc option");
1587 			break;
1588 		case Opt_orlov:
1589 			ext4_msg(sb, KERN_WARNING,
1590 				 "Ignoring deprecated orlov option");
1591 			break;
1592 #ifdef CONFIG_EXT4_FS_XATTR
1593 		case Opt_user_xattr:
1594 			set_opt(sb, XATTR_USER);
1595 			break;
1596 		case Opt_nouser_xattr:
1597 			clear_opt(sb, XATTR_USER);
1598 			break;
1599 #else
1600 		case Opt_user_xattr:
1601 		case Opt_nouser_xattr:
1602 			ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1603 			break;
1604 #endif
1605 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1606 		case Opt_acl:
1607 			set_opt(sb, POSIX_ACL);
1608 			break;
1609 		case Opt_noacl:
1610 			clear_opt(sb, POSIX_ACL);
1611 			break;
1612 #else
1613 		case Opt_acl:
1614 		case Opt_noacl:
1615 			ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1616 			break;
1617 #endif
1618 		case Opt_journal_update:
1619 			/* @@@ FIXME */
1620 			/* Eventually we will want to be able to create
1621 			   a journal file here.  For now, only allow the
1622 			   user to specify an existing inode to be the
1623 			   journal file. */
1624 			if (is_remount) {
1625 				ext4_msg(sb, KERN_ERR,
1626 					 "Cannot specify journal on remount");
1627 				return 0;
1628 			}
1629 			set_opt(sb, UPDATE_JOURNAL);
1630 			break;
1631 		case Opt_journal_dev:
1632 			if (is_remount) {
1633 				ext4_msg(sb, KERN_ERR,
1634 					"Cannot specify journal on remount");
1635 				return 0;
1636 			}
1637 			if (match_int(&args[0], &option))
1638 				return 0;
1639 			*journal_devnum = option;
1640 			break;
1641 		case Opt_journal_checksum:
1642 			set_opt(sb, JOURNAL_CHECKSUM);
1643 			break;
1644 		case Opt_journal_async_commit:
1645 			set_opt(sb, JOURNAL_ASYNC_COMMIT);
1646 			set_opt(sb, JOURNAL_CHECKSUM);
1647 			break;
1648 		case Opt_noload:
1649 			set_opt(sb, NOLOAD);
1650 			break;
1651 		case Opt_commit:
1652 			if (match_int(&args[0], &option))
1653 				return 0;
1654 			if (option < 0)
1655 				return 0;
1656 			if (option == 0)
1657 				option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1658 			sbi->s_commit_interval = HZ * option;
1659 			break;
1660 		case Opt_max_batch_time:
1661 			if (match_int(&args[0], &option))
1662 				return 0;
1663 			if (option < 0)
1664 				return 0;
1665 			if (option == 0)
1666 				option = EXT4_DEF_MAX_BATCH_TIME;
1667 			sbi->s_max_batch_time = option;
1668 			break;
1669 		case Opt_min_batch_time:
1670 			if (match_int(&args[0], &option))
1671 				return 0;
1672 			if (option < 0)
1673 				return 0;
1674 			sbi->s_min_batch_time = option;
1675 			break;
1676 		case Opt_data_journal:
1677 			data_opt = EXT4_MOUNT_JOURNAL_DATA;
1678 			goto datacheck;
1679 		case Opt_data_ordered:
1680 			data_opt = EXT4_MOUNT_ORDERED_DATA;
1681 			goto datacheck;
1682 		case Opt_data_writeback:
1683 			data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1684 		datacheck:
1685 			if (is_remount) {
1686 				if (test_opt(sb, DATA_FLAGS) != data_opt) {
1687 					ext4_msg(sb, KERN_ERR,
1688 						"Cannot change data mode on remount");
1689 					return 0;
1690 				}
1691 			} else {
1692 				clear_opt(sb, DATA_FLAGS);
1693 				sbi->s_mount_opt |= data_opt;
1694 			}
1695 			break;
1696 		case Opt_data_err_abort:
1697 			set_opt(sb, DATA_ERR_ABORT);
1698 			break;
1699 		case Opt_data_err_ignore:
1700 			clear_opt(sb, DATA_ERR_ABORT);
1701 			break;
1702 #ifdef CONFIG_QUOTA
1703 		case Opt_usrjquota:
1704 			if (!set_qf_name(sb, USRQUOTA, &args[0]))
1705 				return 0;
1706 			break;
1707 		case Opt_grpjquota:
1708 			if (!set_qf_name(sb, GRPQUOTA, &args[0]))
1709 				return 0;
1710 			break;
1711 		case Opt_offusrjquota:
1712 			if (!clear_qf_name(sb, USRQUOTA))
1713 				return 0;
1714 			break;
1715 		case Opt_offgrpjquota:
1716 			if (!clear_qf_name(sb, GRPQUOTA))
1717 				return 0;
1718 			break;
1719 
1720 		case Opt_jqfmt_vfsold:
1721 			qfmt = QFMT_VFS_OLD;
1722 			goto set_qf_format;
1723 		case Opt_jqfmt_vfsv0:
1724 			qfmt = QFMT_VFS_V0;
1725 			goto set_qf_format;
1726 		case Opt_jqfmt_vfsv1:
1727 			qfmt = QFMT_VFS_V1;
1728 set_qf_format:
1729 			if (sb_any_quota_loaded(sb) &&
1730 			    sbi->s_jquota_fmt != qfmt) {
1731 				ext4_msg(sb, KERN_ERR, "Cannot change "
1732 					"journaled quota options when "
1733 					"quota turned on");
1734 				return 0;
1735 			}
1736 			sbi->s_jquota_fmt = qfmt;
1737 			break;
1738 		case Opt_quota:
1739 		case Opt_usrquota:
1740 			set_opt(sb, QUOTA);
1741 			set_opt(sb, USRQUOTA);
1742 			break;
1743 		case Opt_grpquota:
1744 			set_opt(sb, QUOTA);
1745 			set_opt(sb, GRPQUOTA);
1746 			break;
1747 		case Opt_noquota:
1748 			if (sb_any_quota_loaded(sb)) {
1749 				ext4_msg(sb, KERN_ERR, "Cannot change quota "
1750 					"options when quota turned on");
1751 				return 0;
1752 			}
1753 			clear_opt(sb, QUOTA);
1754 			clear_opt(sb, USRQUOTA);
1755 			clear_opt(sb, GRPQUOTA);
1756 			break;
1757 #else
1758 		case Opt_quota:
1759 		case Opt_usrquota:
1760 		case Opt_grpquota:
1761 			ext4_msg(sb, KERN_ERR,
1762 				"quota options not supported");
1763 			break;
1764 		case Opt_usrjquota:
1765 		case Opt_grpjquota:
1766 		case Opt_offusrjquota:
1767 		case Opt_offgrpjquota:
1768 		case Opt_jqfmt_vfsold:
1769 		case Opt_jqfmt_vfsv0:
1770 		case Opt_jqfmt_vfsv1:
1771 			ext4_msg(sb, KERN_ERR,
1772 				"journaled quota options not supported");
1773 			break;
1774 		case Opt_noquota:
1775 			break;
1776 #endif
1777 		case Opt_abort:
1778 			sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1779 			break;
1780 		case Opt_nobarrier:
1781 			clear_opt(sb, BARRIER);
1782 			break;
1783 		case Opt_barrier:
1784 			if (args[0].from) {
1785 				if (match_int(&args[0], &option))
1786 					return 0;
1787 			} else
1788 				option = 1;	/* No argument, default to 1 */
1789 			if (option)
1790 				set_opt(sb, BARRIER);
1791 			else
1792 				clear_opt(sb, BARRIER);
1793 			break;
1794 		case Opt_ignore:
1795 			break;
1796 		case Opt_resize:
1797 			if (!is_remount) {
1798 				ext4_msg(sb, KERN_ERR,
1799 					"resize option only available "
1800 					"for remount");
1801 				return 0;
1802 			}
1803 			if (match_int(&args[0], &option) != 0)
1804 				return 0;
1805 			*n_blocks_count = option;
1806 			break;
1807 		case Opt_nobh:
1808 			ext4_msg(sb, KERN_WARNING,
1809 				 "Ignoring deprecated nobh option");
1810 			break;
1811 		case Opt_bh:
1812 			ext4_msg(sb, KERN_WARNING,
1813 				 "Ignoring deprecated bh option");
1814 			break;
1815 		case Opt_i_version:
1816 			set_opt(sb, I_VERSION);
1817 			sb->s_flags |= MS_I_VERSION;
1818 			break;
1819 		case Opt_nodelalloc:
1820 			clear_opt(sb, DELALLOC);
1821 			clear_opt2(sb, EXPLICIT_DELALLOC);
1822 			break;
1823 		case Opt_mblk_io_submit:
1824 			set_opt(sb, MBLK_IO_SUBMIT);
1825 			break;
1826 		case Opt_nomblk_io_submit:
1827 			clear_opt(sb, MBLK_IO_SUBMIT);
1828 			break;
1829 		case Opt_stripe:
1830 			if (match_int(&args[0], &option))
1831 				return 0;
1832 			if (option < 0)
1833 				return 0;
1834 			sbi->s_stripe = option;
1835 			break;
1836 		case Opt_delalloc:
1837 			set_opt(sb, DELALLOC);
1838 			set_opt2(sb, EXPLICIT_DELALLOC);
1839 			break;
1840 		case Opt_block_validity:
1841 			set_opt(sb, BLOCK_VALIDITY);
1842 			break;
1843 		case Opt_noblock_validity:
1844 			clear_opt(sb, BLOCK_VALIDITY);
1845 			break;
1846 		case Opt_inode_readahead_blks:
1847 			if (match_int(&args[0], &option))
1848 				return 0;
1849 			if (option < 0 || option > (1 << 30))
1850 				return 0;
1851 			if (option && !is_power_of_2(option)) {
1852 				ext4_msg(sb, KERN_ERR,
1853 					 "EXT4-fs: inode_readahead_blks"
1854 					 " must be a power of 2");
1855 				return 0;
1856 			}
1857 			sbi->s_inode_readahead_blks = option;
1858 			break;
1859 		case Opt_journal_ioprio:
1860 			if (match_int(&args[0], &option))
1861 				return 0;
1862 			if (option < 0 || option > 7)
1863 				break;
1864 			*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1865 							    option);
1866 			break;
1867 		case Opt_noauto_da_alloc:
1868 			set_opt(sb, NO_AUTO_DA_ALLOC);
1869 			break;
1870 		case Opt_auto_da_alloc:
1871 			if (args[0].from) {
1872 				if (match_int(&args[0], &option))
1873 					return 0;
1874 			} else
1875 				option = 1;	/* No argument, default to 1 */
1876 			if (option)
1877 				clear_opt(sb, NO_AUTO_DA_ALLOC);
1878 			else
1879 				set_opt(sb,NO_AUTO_DA_ALLOC);
1880 			break;
1881 		case Opt_discard:
1882 			set_opt(sb, DISCARD);
1883 			break;
1884 		case Opt_nodiscard:
1885 			clear_opt(sb, DISCARD);
1886 			break;
1887 		case Opt_dioread_nolock:
1888 			set_opt(sb, DIOREAD_NOLOCK);
1889 			break;
1890 		case Opt_dioread_lock:
1891 			clear_opt(sb, DIOREAD_NOLOCK);
1892 			break;
1893 		case Opt_init_inode_table:
1894 			set_opt(sb, INIT_INODE_TABLE);
1895 			if (args[0].from) {
1896 				if (match_int(&args[0], &option))
1897 					return 0;
1898 			} else
1899 				option = EXT4_DEF_LI_WAIT_MULT;
1900 			if (option < 0)
1901 				return 0;
1902 			sbi->s_li_wait_mult = option;
1903 			break;
1904 		case Opt_noinit_inode_table:
1905 			clear_opt(sb, INIT_INODE_TABLE);
1906 			break;
1907 		default:
1908 			ext4_msg(sb, KERN_ERR,
1909 			       "Unrecognized mount option \"%s\" "
1910 			       "or missing value", p);
1911 			return 0;
1912 		}
1913 	}
1914 #ifdef CONFIG_QUOTA
1915 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1916 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1917 			clear_opt(sb, USRQUOTA);
1918 
1919 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1920 			clear_opt(sb, GRPQUOTA);
1921 
1922 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1923 			ext4_msg(sb, KERN_ERR, "old and new quota "
1924 					"format mixing");
1925 			return 0;
1926 		}
1927 
1928 		if (!sbi->s_jquota_fmt) {
1929 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1930 					"not specified");
1931 			return 0;
1932 		}
1933 	} else {
1934 		if (sbi->s_jquota_fmt) {
1935 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1936 					"specified with no journaling "
1937 					"enabled");
1938 			return 0;
1939 		}
1940 	}
1941 #endif
1942 	return 1;
1943 }
1944 
1945 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1946 			    int read_only)
1947 {
1948 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1949 	int res = 0;
1950 
1951 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1952 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1953 			 "forcing read-only mode");
1954 		res = MS_RDONLY;
1955 	}
1956 	if (read_only)
1957 		goto done;
1958 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1959 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1960 			 "running e2fsck is recommended");
1961 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1962 		ext4_msg(sb, KERN_WARNING,
1963 			 "warning: mounting fs with errors, "
1964 			 "running e2fsck is recommended");
1965 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1966 		 le16_to_cpu(es->s_mnt_count) >=
1967 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1968 		ext4_msg(sb, KERN_WARNING,
1969 			 "warning: maximal mount count reached, "
1970 			 "running e2fsck is recommended");
1971 	else if (le32_to_cpu(es->s_checkinterval) &&
1972 		(le32_to_cpu(es->s_lastcheck) +
1973 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1974 		ext4_msg(sb, KERN_WARNING,
1975 			 "warning: checktime reached, "
1976 			 "running e2fsck is recommended");
1977 	if (!sbi->s_journal)
1978 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1979 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1980 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1981 	le16_add_cpu(&es->s_mnt_count, 1);
1982 	es->s_mtime = cpu_to_le32(get_seconds());
1983 	ext4_update_dynamic_rev(sb);
1984 	if (sbi->s_journal)
1985 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1986 
1987 	ext4_commit_super(sb, 1);
1988 done:
1989 	if (test_opt(sb, DEBUG))
1990 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1991 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1992 			sb->s_blocksize,
1993 			sbi->s_groups_count,
1994 			EXT4_BLOCKS_PER_GROUP(sb),
1995 			EXT4_INODES_PER_GROUP(sb),
1996 			sbi->s_mount_opt, sbi->s_mount_opt2);
1997 
1998 	cleancache_init_fs(sb);
1999 	return res;
2000 }
2001 
2002 static int ext4_fill_flex_info(struct super_block *sb)
2003 {
2004 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2005 	struct ext4_group_desc *gdp = NULL;
2006 	ext4_group_t flex_group_count;
2007 	ext4_group_t flex_group;
2008 	int groups_per_flex = 0;
2009 	size_t size;
2010 	int i;
2011 
2012 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2013 	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
2014 
2015 	if (groups_per_flex < 2) {
2016 		sbi->s_log_groups_per_flex = 0;
2017 		return 1;
2018 	}
2019 
2020 	/* We allocate both existing and potentially added groups */
2021 	flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
2022 			((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
2023 			      EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
2024 	size = flex_group_count * sizeof(struct flex_groups);
2025 	sbi->s_flex_groups = ext4_kvzalloc(size, GFP_KERNEL);
2026 	if (sbi->s_flex_groups == NULL) {
2027 		ext4_msg(sb, KERN_ERR, "not enough memory for %u flex groups",
2028 			 flex_group_count);
2029 		goto failed;
2030 	}
2031 
2032 	for (i = 0; i < sbi->s_groups_count; i++) {
2033 		gdp = ext4_get_group_desc(sb, i, NULL);
2034 
2035 		flex_group = ext4_flex_group(sbi, i);
2036 		atomic_add(ext4_free_inodes_count(sb, gdp),
2037 			   &sbi->s_flex_groups[flex_group].free_inodes);
2038 		atomic_add(ext4_free_group_clusters(sb, gdp),
2039 			   &sbi->s_flex_groups[flex_group].free_clusters);
2040 		atomic_add(ext4_used_dirs_count(sb, gdp),
2041 			   &sbi->s_flex_groups[flex_group].used_dirs);
2042 	}
2043 
2044 	return 1;
2045 failed:
2046 	return 0;
2047 }
2048 
2049 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2050 			    struct ext4_group_desc *gdp)
2051 {
2052 	__u16 crc = 0;
2053 
2054 	if (sbi->s_es->s_feature_ro_compat &
2055 	    cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
2056 		int offset = offsetof(struct ext4_group_desc, bg_checksum);
2057 		__le32 le_group = cpu_to_le32(block_group);
2058 
2059 		crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2060 		crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2061 		crc = crc16(crc, (__u8 *)gdp, offset);
2062 		offset += sizeof(gdp->bg_checksum); /* skip checksum */
2063 		/* for checksum of struct ext4_group_desc do the rest...*/
2064 		if ((sbi->s_es->s_feature_incompat &
2065 		     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2066 		    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2067 			crc = crc16(crc, (__u8 *)gdp + offset,
2068 				    le16_to_cpu(sbi->s_es->s_desc_size) -
2069 					offset);
2070 	}
2071 
2072 	return cpu_to_le16(crc);
2073 }
2074 
2075 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
2076 				struct ext4_group_desc *gdp)
2077 {
2078 	if ((sbi->s_es->s_feature_ro_compat &
2079 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
2080 	    (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
2081 		return 0;
2082 
2083 	return 1;
2084 }
2085 
2086 /* Called at mount-time, super-block is locked */
2087 static int ext4_check_descriptors(struct super_block *sb,
2088 				  ext4_group_t *first_not_zeroed)
2089 {
2090 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2091 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2092 	ext4_fsblk_t last_block;
2093 	ext4_fsblk_t block_bitmap;
2094 	ext4_fsblk_t inode_bitmap;
2095 	ext4_fsblk_t inode_table;
2096 	int flexbg_flag = 0;
2097 	ext4_group_t i, grp = sbi->s_groups_count;
2098 
2099 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2100 		flexbg_flag = 1;
2101 
2102 	ext4_debug("Checking group descriptors");
2103 
2104 	for (i = 0; i < sbi->s_groups_count; i++) {
2105 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2106 
2107 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2108 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2109 		else
2110 			last_block = first_block +
2111 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2112 
2113 		if ((grp == sbi->s_groups_count) &&
2114 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2115 			grp = i;
2116 
2117 		block_bitmap = ext4_block_bitmap(sb, gdp);
2118 		if (block_bitmap < first_block || block_bitmap > last_block) {
2119 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2120 			       "Block bitmap for group %u not in group "
2121 			       "(block %llu)!", i, block_bitmap);
2122 			return 0;
2123 		}
2124 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2125 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2126 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2127 			       "Inode bitmap for group %u not in group "
2128 			       "(block %llu)!", i, inode_bitmap);
2129 			return 0;
2130 		}
2131 		inode_table = ext4_inode_table(sb, gdp);
2132 		if (inode_table < first_block ||
2133 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2134 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2135 			       "Inode table for group %u not in group "
2136 			       "(block %llu)!", i, inode_table);
2137 			return 0;
2138 		}
2139 		ext4_lock_group(sb, i);
2140 		if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
2141 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2142 				 "Checksum for group %u failed (%u!=%u)",
2143 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2144 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2145 			if (!(sb->s_flags & MS_RDONLY)) {
2146 				ext4_unlock_group(sb, i);
2147 				return 0;
2148 			}
2149 		}
2150 		ext4_unlock_group(sb, i);
2151 		if (!flexbg_flag)
2152 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2153 	}
2154 	if (NULL != first_not_zeroed)
2155 		*first_not_zeroed = grp;
2156 
2157 	ext4_free_blocks_count_set(sbi->s_es,
2158 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2159 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2160 	return 1;
2161 }
2162 
2163 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2164  * the superblock) which were deleted from all directories, but held open by
2165  * a process at the time of a crash.  We walk the list and try to delete these
2166  * inodes at recovery time (only with a read-write filesystem).
2167  *
2168  * In order to keep the orphan inode chain consistent during traversal (in
2169  * case of crash during recovery), we link each inode into the superblock
2170  * orphan list_head and handle it the same way as an inode deletion during
2171  * normal operation (which journals the operations for us).
2172  *
2173  * We only do an iget() and an iput() on each inode, which is very safe if we
2174  * accidentally point at an in-use or already deleted inode.  The worst that
2175  * can happen in this case is that we get a "bit already cleared" message from
2176  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2177  * e2fsck was run on this filesystem, and it must have already done the orphan
2178  * inode cleanup for us, so we can safely abort without any further action.
2179  */
2180 static void ext4_orphan_cleanup(struct super_block *sb,
2181 				struct ext4_super_block *es)
2182 {
2183 	unsigned int s_flags = sb->s_flags;
2184 	int nr_orphans = 0, nr_truncates = 0;
2185 #ifdef CONFIG_QUOTA
2186 	int i;
2187 #endif
2188 	if (!es->s_last_orphan) {
2189 		jbd_debug(4, "no orphan inodes to clean up\n");
2190 		return;
2191 	}
2192 
2193 	if (bdev_read_only(sb->s_bdev)) {
2194 		ext4_msg(sb, KERN_ERR, "write access "
2195 			"unavailable, skipping orphan cleanup");
2196 		return;
2197 	}
2198 
2199 	/* Check if feature set would not allow a r/w mount */
2200 	if (!ext4_feature_set_ok(sb, 0)) {
2201 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2202 			 "unknown ROCOMPAT features");
2203 		return;
2204 	}
2205 
2206 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2207 		if (es->s_last_orphan)
2208 			jbd_debug(1, "Errors on filesystem, "
2209 				  "clearing orphan list.\n");
2210 		es->s_last_orphan = 0;
2211 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2212 		return;
2213 	}
2214 
2215 	if (s_flags & MS_RDONLY) {
2216 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2217 		sb->s_flags &= ~MS_RDONLY;
2218 	}
2219 #ifdef CONFIG_QUOTA
2220 	/* Needed for iput() to work correctly and not trash data */
2221 	sb->s_flags |= MS_ACTIVE;
2222 	/* Turn on quotas so that they are updated correctly */
2223 	for (i = 0; i < MAXQUOTAS; i++) {
2224 		if (EXT4_SB(sb)->s_qf_names[i]) {
2225 			int ret = ext4_quota_on_mount(sb, i);
2226 			if (ret < 0)
2227 				ext4_msg(sb, KERN_ERR,
2228 					"Cannot turn on journaled "
2229 					"quota: error %d", ret);
2230 		}
2231 	}
2232 #endif
2233 
2234 	while (es->s_last_orphan) {
2235 		struct inode *inode;
2236 
2237 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2238 		if (IS_ERR(inode)) {
2239 			es->s_last_orphan = 0;
2240 			break;
2241 		}
2242 
2243 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2244 		dquot_initialize(inode);
2245 		if (inode->i_nlink) {
2246 			ext4_msg(sb, KERN_DEBUG,
2247 				"%s: truncating inode %lu to %lld bytes",
2248 				__func__, inode->i_ino, inode->i_size);
2249 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2250 				  inode->i_ino, inode->i_size);
2251 			ext4_truncate(inode);
2252 			nr_truncates++;
2253 		} else {
2254 			ext4_msg(sb, KERN_DEBUG,
2255 				"%s: deleting unreferenced inode %lu",
2256 				__func__, inode->i_ino);
2257 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2258 				  inode->i_ino);
2259 			nr_orphans++;
2260 		}
2261 		iput(inode);  /* The delete magic happens here! */
2262 	}
2263 
2264 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2265 
2266 	if (nr_orphans)
2267 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2268 		       PLURAL(nr_orphans));
2269 	if (nr_truncates)
2270 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2271 		       PLURAL(nr_truncates));
2272 #ifdef CONFIG_QUOTA
2273 	/* Turn quotas off */
2274 	for (i = 0; i < MAXQUOTAS; i++) {
2275 		if (sb_dqopt(sb)->files[i])
2276 			dquot_quota_off(sb, i);
2277 	}
2278 #endif
2279 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2280 }
2281 
2282 /*
2283  * Maximal extent format file size.
2284  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2285  * extent format containers, within a sector_t, and within i_blocks
2286  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2287  * so that won't be a limiting factor.
2288  *
2289  * However there is other limiting factor. We do store extents in the form
2290  * of starting block and length, hence the resulting length of the extent
2291  * covering maximum file size must fit into on-disk format containers as
2292  * well. Given that length is always by 1 unit bigger than max unit (because
2293  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2294  *
2295  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2296  */
2297 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2298 {
2299 	loff_t res;
2300 	loff_t upper_limit = MAX_LFS_FILESIZE;
2301 
2302 	/* small i_blocks in vfs inode? */
2303 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2304 		/*
2305 		 * CONFIG_LBDAF is not enabled implies the inode
2306 		 * i_block represent total blocks in 512 bytes
2307 		 * 32 == size of vfs inode i_blocks * 8
2308 		 */
2309 		upper_limit = (1LL << 32) - 1;
2310 
2311 		/* total blocks in file system block size */
2312 		upper_limit >>= (blkbits - 9);
2313 		upper_limit <<= blkbits;
2314 	}
2315 
2316 	/*
2317 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2318 	 * by one fs block, so ee_len can cover the extent of maximum file
2319 	 * size
2320 	 */
2321 	res = (1LL << 32) - 1;
2322 	res <<= blkbits;
2323 
2324 	/* Sanity check against vm- & vfs- imposed limits */
2325 	if (res > upper_limit)
2326 		res = upper_limit;
2327 
2328 	return res;
2329 }
2330 
2331 /*
2332  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2333  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2334  * We need to be 1 filesystem block less than the 2^48 sector limit.
2335  */
2336 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2337 {
2338 	loff_t res = EXT4_NDIR_BLOCKS;
2339 	int meta_blocks;
2340 	loff_t upper_limit;
2341 	/* This is calculated to be the largest file size for a dense, block
2342 	 * mapped file such that the file's total number of 512-byte sectors,
2343 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2344 	 *
2345 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2346 	 * number of 512-byte sectors of the file.
2347 	 */
2348 
2349 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2350 		/*
2351 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2352 		 * the inode i_block field represents total file blocks in
2353 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2354 		 */
2355 		upper_limit = (1LL << 32) - 1;
2356 
2357 		/* total blocks in file system block size */
2358 		upper_limit >>= (bits - 9);
2359 
2360 	} else {
2361 		/*
2362 		 * We use 48 bit ext4_inode i_blocks
2363 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2364 		 * represent total number of blocks in
2365 		 * file system block size
2366 		 */
2367 		upper_limit = (1LL << 48) - 1;
2368 
2369 	}
2370 
2371 	/* indirect blocks */
2372 	meta_blocks = 1;
2373 	/* double indirect blocks */
2374 	meta_blocks += 1 + (1LL << (bits-2));
2375 	/* tripple indirect blocks */
2376 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2377 
2378 	upper_limit -= meta_blocks;
2379 	upper_limit <<= bits;
2380 
2381 	res += 1LL << (bits-2);
2382 	res += 1LL << (2*(bits-2));
2383 	res += 1LL << (3*(bits-2));
2384 	res <<= bits;
2385 	if (res > upper_limit)
2386 		res = upper_limit;
2387 
2388 	if (res > MAX_LFS_FILESIZE)
2389 		res = MAX_LFS_FILESIZE;
2390 
2391 	return res;
2392 }
2393 
2394 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2395 				   ext4_fsblk_t logical_sb_block, int nr)
2396 {
2397 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2398 	ext4_group_t bg, first_meta_bg;
2399 	int has_super = 0;
2400 
2401 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2402 
2403 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2404 	    nr < first_meta_bg)
2405 		return logical_sb_block + nr + 1;
2406 	bg = sbi->s_desc_per_block * nr;
2407 	if (ext4_bg_has_super(sb, bg))
2408 		has_super = 1;
2409 
2410 	return (has_super + ext4_group_first_block_no(sb, bg));
2411 }
2412 
2413 /**
2414  * ext4_get_stripe_size: Get the stripe size.
2415  * @sbi: In memory super block info
2416  *
2417  * If we have specified it via mount option, then
2418  * use the mount option value. If the value specified at mount time is
2419  * greater than the blocks per group use the super block value.
2420  * If the super block value is greater than blocks per group return 0.
2421  * Allocator needs it be less than blocks per group.
2422  *
2423  */
2424 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2425 {
2426 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2427 	unsigned long stripe_width =
2428 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2429 	int ret;
2430 
2431 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2432 		ret = sbi->s_stripe;
2433 	else if (stripe_width <= sbi->s_blocks_per_group)
2434 		ret = stripe_width;
2435 	else if (stride <= sbi->s_blocks_per_group)
2436 		ret = stride;
2437 	else
2438 		ret = 0;
2439 
2440 	/*
2441 	 * If the stripe width is 1, this makes no sense and
2442 	 * we set it to 0 to turn off stripe handling code.
2443 	 */
2444 	if (ret <= 1)
2445 		ret = 0;
2446 
2447 	return ret;
2448 }
2449 
2450 /* sysfs supprt */
2451 
2452 struct ext4_attr {
2453 	struct attribute attr;
2454 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2455 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2456 			 const char *, size_t);
2457 	int offset;
2458 };
2459 
2460 static int parse_strtoul(const char *buf,
2461 		unsigned long max, unsigned long *value)
2462 {
2463 	char *endp;
2464 
2465 	*value = simple_strtoul(skip_spaces(buf), &endp, 0);
2466 	endp = skip_spaces(endp);
2467 	if (*endp || *value > max)
2468 		return -EINVAL;
2469 
2470 	return 0;
2471 }
2472 
2473 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2474 					      struct ext4_sb_info *sbi,
2475 					      char *buf)
2476 {
2477 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2478 		(s64) EXT4_C2B(sbi,
2479 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2480 }
2481 
2482 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2483 					 struct ext4_sb_info *sbi, char *buf)
2484 {
2485 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2486 
2487 	if (!sb->s_bdev->bd_part)
2488 		return snprintf(buf, PAGE_SIZE, "0\n");
2489 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2490 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2491 			 sbi->s_sectors_written_start) >> 1);
2492 }
2493 
2494 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2495 					  struct ext4_sb_info *sbi, char *buf)
2496 {
2497 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2498 
2499 	if (!sb->s_bdev->bd_part)
2500 		return snprintf(buf, PAGE_SIZE, "0\n");
2501 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2502 			(unsigned long long)(sbi->s_kbytes_written +
2503 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2504 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2505 }
2506 
2507 static ssize_t extent_cache_hits_show(struct ext4_attr *a,
2508 				      struct ext4_sb_info *sbi, char *buf)
2509 {
2510 	return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_hits);
2511 }
2512 
2513 static ssize_t extent_cache_misses_show(struct ext4_attr *a,
2514 					struct ext4_sb_info *sbi, char *buf)
2515 {
2516 	return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_misses);
2517 }
2518 
2519 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2520 					  struct ext4_sb_info *sbi,
2521 					  const char *buf, size_t count)
2522 {
2523 	unsigned long t;
2524 
2525 	if (parse_strtoul(buf, 0x40000000, &t))
2526 		return -EINVAL;
2527 
2528 	if (t && !is_power_of_2(t))
2529 		return -EINVAL;
2530 
2531 	sbi->s_inode_readahead_blks = t;
2532 	return count;
2533 }
2534 
2535 static ssize_t sbi_ui_show(struct ext4_attr *a,
2536 			   struct ext4_sb_info *sbi, char *buf)
2537 {
2538 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2539 
2540 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2541 }
2542 
2543 static ssize_t sbi_ui_store(struct ext4_attr *a,
2544 			    struct ext4_sb_info *sbi,
2545 			    const char *buf, size_t count)
2546 {
2547 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2548 	unsigned long t;
2549 
2550 	if (parse_strtoul(buf, 0xffffffff, &t))
2551 		return -EINVAL;
2552 	*ui = t;
2553 	return count;
2554 }
2555 
2556 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2557 static struct ext4_attr ext4_attr_##_name = {			\
2558 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2559 	.show	= _show,					\
2560 	.store	= _store,					\
2561 	.offset = offsetof(struct ext4_sb_info, _elname),	\
2562 }
2563 #define EXT4_ATTR(name, mode, show, store) \
2564 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2565 
2566 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2567 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2568 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2569 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2570 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2571 #define ATTR_LIST(name) &ext4_attr_##name.attr
2572 
2573 EXT4_RO_ATTR(delayed_allocation_blocks);
2574 EXT4_RO_ATTR(session_write_kbytes);
2575 EXT4_RO_ATTR(lifetime_write_kbytes);
2576 EXT4_RO_ATTR(extent_cache_hits);
2577 EXT4_RO_ATTR(extent_cache_misses);
2578 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2579 		 inode_readahead_blks_store, s_inode_readahead_blks);
2580 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2581 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2582 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2583 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2584 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2585 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2586 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2587 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2588 
2589 static struct attribute *ext4_attrs[] = {
2590 	ATTR_LIST(delayed_allocation_blocks),
2591 	ATTR_LIST(session_write_kbytes),
2592 	ATTR_LIST(lifetime_write_kbytes),
2593 	ATTR_LIST(extent_cache_hits),
2594 	ATTR_LIST(extent_cache_misses),
2595 	ATTR_LIST(inode_readahead_blks),
2596 	ATTR_LIST(inode_goal),
2597 	ATTR_LIST(mb_stats),
2598 	ATTR_LIST(mb_max_to_scan),
2599 	ATTR_LIST(mb_min_to_scan),
2600 	ATTR_LIST(mb_order2_req),
2601 	ATTR_LIST(mb_stream_req),
2602 	ATTR_LIST(mb_group_prealloc),
2603 	ATTR_LIST(max_writeback_mb_bump),
2604 	NULL,
2605 };
2606 
2607 /* Features this copy of ext4 supports */
2608 EXT4_INFO_ATTR(lazy_itable_init);
2609 EXT4_INFO_ATTR(batched_discard);
2610 
2611 static struct attribute *ext4_feat_attrs[] = {
2612 	ATTR_LIST(lazy_itable_init),
2613 	ATTR_LIST(batched_discard),
2614 	NULL,
2615 };
2616 
2617 static ssize_t ext4_attr_show(struct kobject *kobj,
2618 			      struct attribute *attr, char *buf)
2619 {
2620 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2621 						s_kobj);
2622 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2623 
2624 	return a->show ? a->show(a, sbi, buf) : 0;
2625 }
2626 
2627 static ssize_t ext4_attr_store(struct kobject *kobj,
2628 			       struct attribute *attr,
2629 			       const char *buf, size_t len)
2630 {
2631 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2632 						s_kobj);
2633 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2634 
2635 	return a->store ? a->store(a, sbi, buf, len) : 0;
2636 }
2637 
2638 static void ext4_sb_release(struct kobject *kobj)
2639 {
2640 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2641 						s_kobj);
2642 	complete(&sbi->s_kobj_unregister);
2643 }
2644 
2645 static const struct sysfs_ops ext4_attr_ops = {
2646 	.show	= ext4_attr_show,
2647 	.store	= ext4_attr_store,
2648 };
2649 
2650 static struct kobj_type ext4_ktype = {
2651 	.default_attrs	= ext4_attrs,
2652 	.sysfs_ops	= &ext4_attr_ops,
2653 	.release	= ext4_sb_release,
2654 };
2655 
2656 static void ext4_feat_release(struct kobject *kobj)
2657 {
2658 	complete(&ext4_feat->f_kobj_unregister);
2659 }
2660 
2661 static struct kobj_type ext4_feat_ktype = {
2662 	.default_attrs	= ext4_feat_attrs,
2663 	.sysfs_ops	= &ext4_attr_ops,
2664 	.release	= ext4_feat_release,
2665 };
2666 
2667 /*
2668  * Check whether this filesystem can be mounted based on
2669  * the features present and the RDONLY/RDWR mount requested.
2670  * Returns 1 if this filesystem can be mounted as requested,
2671  * 0 if it cannot be.
2672  */
2673 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2674 {
2675 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2676 		ext4_msg(sb, KERN_ERR,
2677 			"Couldn't mount because of "
2678 			"unsupported optional features (%x)",
2679 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2680 			~EXT4_FEATURE_INCOMPAT_SUPP));
2681 		return 0;
2682 	}
2683 
2684 	if (readonly)
2685 		return 1;
2686 
2687 	/* Check that feature set is OK for a read-write mount */
2688 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2689 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2690 			 "unsupported optional features (%x)",
2691 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2692 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2693 		return 0;
2694 	}
2695 	/*
2696 	 * Large file size enabled file system can only be mounted
2697 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2698 	 */
2699 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2700 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2701 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2702 				 "cannot be mounted RDWR without "
2703 				 "CONFIG_LBDAF");
2704 			return 0;
2705 		}
2706 	}
2707 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2708 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2709 		ext4_msg(sb, KERN_ERR,
2710 			 "Can't support bigalloc feature without "
2711 			 "extents feature\n");
2712 		return 0;
2713 	}
2714 	return 1;
2715 }
2716 
2717 /*
2718  * This function is called once a day if we have errors logged
2719  * on the file system
2720  */
2721 static void print_daily_error_info(unsigned long arg)
2722 {
2723 	struct super_block *sb = (struct super_block *) arg;
2724 	struct ext4_sb_info *sbi;
2725 	struct ext4_super_block *es;
2726 
2727 	sbi = EXT4_SB(sb);
2728 	es = sbi->s_es;
2729 
2730 	if (es->s_error_count)
2731 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2732 			 le32_to_cpu(es->s_error_count));
2733 	if (es->s_first_error_time) {
2734 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2735 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2736 		       (int) sizeof(es->s_first_error_func),
2737 		       es->s_first_error_func,
2738 		       le32_to_cpu(es->s_first_error_line));
2739 		if (es->s_first_error_ino)
2740 			printk(": inode %u",
2741 			       le32_to_cpu(es->s_first_error_ino));
2742 		if (es->s_first_error_block)
2743 			printk(": block %llu", (unsigned long long)
2744 			       le64_to_cpu(es->s_first_error_block));
2745 		printk("\n");
2746 	}
2747 	if (es->s_last_error_time) {
2748 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2749 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2750 		       (int) sizeof(es->s_last_error_func),
2751 		       es->s_last_error_func,
2752 		       le32_to_cpu(es->s_last_error_line));
2753 		if (es->s_last_error_ino)
2754 			printk(": inode %u",
2755 			       le32_to_cpu(es->s_last_error_ino));
2756 		if (es->s_last_error_block)
2757 			printk(": block %llu", (unsigned long long)
2758 			       le64_to_cpu(es->s_last_error_block));
2759 		printk("\n");
2760 	}
2761 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2762 }
2763 
2764 /* Find next suitable group and run ext4_init_inode_table */
2765 static int ext4_run_li_request(struct ext4_li_request *elr)
2766 {
2767 	struct ext4_group_desc *gdp = NULL;
2768 	ext4_group_t group, ngroups;
2769 	struct super_block *sb;
2770 	unsigned long timeout = 0;
2771 	int ret = 0;
2772 
2773 	sb = elr->lr_super;
2774 	ngroups = EXT4_SB(sb)->s_groups_count;
2775 
2776 	for (group = elr->lr_next_group; group < ngroups; group++) {
2777 		gdp = ext4_get_group_desc(sb, group, NULL);
2778 		if (!gdp) {
2779 			ret = 1;
2780 			break;
2781 		}
2782 
2783 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2784 			break;
2785 	}
2786 
2787 	if (group == ngroups)
2788 		ret = 1;
2789 
2790 	if (!ret) {
2791 		timeout = jiffies;
2792 		ret = ext4_init_inode_table(sb, group,
2793 					    elr->lr_timeout ? 0 : 1);
2794 		if (elr->lr_timeout == 0) {
2795 			timeout = (jiffies - timeout) *
2796 				  elr->lr_sbi->s_li_wait_mult;
2797 			elr->lr_timeout = timeout;
2798 		}
2799 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2800 		elr->lr_next_group = group + 1;
2801 	}
2802 
2803 	return ret;
2804 }
2805 
2806 /*
2807  * Remove lr_request from the list_request and free the
2808  * request structure. Should be called with li_list_mtx held
2809  */
2810 static void ext4_remove_li_request(struct ext4_li_request *elr)
2811 {
2812 	struct ext4_sb_info *sbi;
2813 
2814 	if (!elr)
2815 		return;
2816 
2817 	sbi = elr->lr_sbi;
2818 
2819 	list_del(&elr->lr_request);
2820 	sbi->s_li_request = NULL;
2821 	kfree(elr);
2822 }
2823 
2824 static void ext4_unregister_li_request(struct super_block *sb)
2825 {
2826 	mutex_lock(&ext4_li_mtx);
2827 	if (!ext4_li_info) {
2828 		mutex_unlock(&ext4_li_mtx);
2829 		return;
2830 	}
2831 
2832 	mutex_lock(&ext4_li_info->li_list_mtx);
2833 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2834 	mutex_unlock(&ext4_li_info->li_list_mtx);
2835 	mutex_unlock(&ext4_li_mtx);
2836 }
2837 
2838 static struct task_struct *ext4_lazyinit_task;
2839 
2840 /*
2841  * This is the function where ext4lazyinit thread lives. It walks
2842  * through the request list searching for next scheduled filesystem.
2843  * When such a fs is found, run the lazy initialization request
2844  * (ext4_rn_li_request) and keep track of the time spend in this
2845  * function. Based on that time we compute next schedule time of
2846  * the request. When walking through the list is complete, compute
2847  * next waking time and put itself into sleep.
2848  */
2849 static int ext4_lazyinit_thread(void *arg)
2850 {
2851 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2852 	struct list_head *pos, *n;
2853 	struct ext4_li_request *elr;
2854 	unsigned long next_wakeup, cur;
2855 
2856 	BUG_ON(NULL == eli);
2857 
2858 cont_thread:
2859 	while (true) {
2860 		next_wakeup = MAX_JIFFY_OFFSET;
2861 
2862 		mutex_lock(&eli->li_list_mtx);
2863 		if (list_empty(&eli->li_request_list)) {
2864 			mutex_unlock(&eli->li_list_mtx);
2865 			goto exit_thread;
2866 		}
2867 
2868 		list_for_each_safe(pos, n, &eli->li_request_list) {
2869 			elr = list_entry(pos, struct ext4_li_request,
2870 					 lr_request);
2871 
2872 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2873 				if (ext4_run_li_request(elr) != 0) {
2874 					/* error, remove the lazy_init job */
2875 					ext4_remove_li_request(elr);
2876 					continue;
2877 				}
2878 			}
2879 
2880 			if (time_before(elr->lr_next_sched, next_wakeup))
2881 				next_wakeup = elr->lr_next_sched;
2882 		}
2883 		mutex_unlock(&eli->li_list_mtx);
2884 
2885 		if (freezing(current))
2886 			refrigerator();
2887 
2888 		cur = jiffies;
2889 		if ((time_after_eq(cur, next_wakeup)) ||
2890 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2891 			cond_resched();
2892 			continue;
2893 		}
2894 
2895 		schedule_timeout_interruptible(next_wakeup - cur);
2896 
2897 		if (kthread_should_stop()) {
2898 			ext4_clear_request_list();
2899 			goto exit_thread;
2900 		}
2901 	}
2902 
2903 exit_thread:
2904 	/*
2905 	 * It looks like the request list is empty, but we need
2906 	 * to check it under the li_list_mtx lock, to prevent any
2907 	 * additions into it, and of course we should lock ext4_li_mtx
2908 	 * to atomically free the list and ext4_li_info, because at
2909 	 * this point another ext4 filesystem could be registering
2910 	 * new one.
2911 	 */
2912 	mutex_lock(&ext4_li_mtx);
2913 	mutex_lock(&eli->li_list_mtx);
2914 	if (!list_empty(&eli->li_request_list)) {
2915 		mutex_unlock(&eli->li_list_mtx);
2916 		mutex_unlock(&ext4_li_mtx);
2917 		goto cont_thread;
2918 	}
2919 	mutex_unlock(&eli->li_list_mtx);
2920 	kfree(ext4_li_info);
2921 	ext4_li_info = NULL;
2922 	mutex_unlock(&ext4_li_mtx);
2923 
2924 	return 0;
2925 }
2926 
2927 static void ext4_clear_request_list(void)
2928 {
2929 	struct list_head *pos, *n;
2930 	struct ext4_li_request *elr;
2931 
2932 	mutex_lock(&ext4_li_info->li_list_mtx);
2933 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2934 		elr = list_entry(pos, struct ext4_li_request,
2935 				 lr_request);
2936 		ext4_remove_li_request(elr);
2937 	}
2938 	mutex_unlock(&ext4_li_info->li_list_mtx);
2939 }
2940 
2941 static int ext4_run_lazyinit_thread(void)
2942 {
2943 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2944 					 ext4_li_info, "ext4lazyinit");
2945 	if (IS_ERR(ext4_lazyinit_task)) {
2946 		int err = PTR_ERR(ext4_lazyinit_task);
2947 		ext4_clear_request_list();
2948 		kfree(ext4_li_info);
2949 		ext4_li_info = NULL;
2950 		printk(KERN_CRIT "EXT4: error %d creating inode table "
2951 				 "initialization thread\n",
2952 				 err);
2953 		return err;
2954 	}
2955 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2956 	return 0;
2957 }
2958 
2959 /*
2960  * Check whether it make sense to run itable init. thread or not.
2961  * If there is at least one uninitialized inode table, return
2962  * corresponding group number, else the loop goes through all
2963  * groups and return total number of groups.
2964  */
2965 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2966 {
2967 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2968 	struct ext4_group_desc *gdp = NULL;
2969 
2970 	for (group = 0; group < ngroups; group++) {
2971 		gdp = ext4_get_group_desc(sb, group, NULL);
2972 		if (!gdp)
2973 			continue;
2974 
2975 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2976 			break;
2977 	}
2978 
2979 	return group;
2980 }
2981 
2982 static int ext4_li_info_new(void)
2983 {
2984 	struct ext4_lazy_init *eli = NULL;
2985 
2986 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2987 	if (!eli)
2988 		return -ENOMEM;
2989 
2990 	INIT_LIST_HEAD(&eli->li_request_list);
2991 	mutex_init(&eli->li_list_mtx);
2992 
2993 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2994 
2995 	ext4_li_info = eli;
2996 
2997 	return 0;
2998 }
2999 
3000 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3001 					    ext4_group_t start)
3002 {
3003 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3004 	struct ext4_li_request *elr;
3005 	unsigned long rnd;
3006 
3007 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3008 	if (!elr)
3009 		return NULL;
3010 
3011 	elr->lr_super = sb;
3012 	elr->lr_sbi = sbi;
3013 	elr->lr_next_group = start;
3014 
3015 	/*
3016 	 * Randomize first schedule time of the request to
3017 	 * spread the inode table initialization requests
3018 	 * better.
3019 	 */
3020 	get_random_bytes(&rnd, sizeof(rnd));
3021 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
3022 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3023 
3024 	return elr;
3025 }
3026 
3027 static int ext4_register_li_request(struct super_block *sb,
3028 				    ext4_group_t first_not_zeroed)
3029 {
3030 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3031 	struct ext4_li_request *elr;
3032 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3033 	int ret = 0;
3034 
3035 	if (sbi->s_li_request != NULL) {
3036 		/*
3037 		 * Reset timeout so it can be computed again, because
3038 		 * s_li_wait_mult might have changed.
3039 		 */
3040 		sbi->s_li_request->lr_timeout = 0;
3041 		return 0;
3042 	}
3043 
3044 	if (first_not_zeroed == ngroups ||
3045 	    (sb->s_flags & MS_RDONLY) ||
3046 	    !test_opt(sb, INIT_INODE_TABLE))
3047 		return 0;
3048 
3049 	elr = ext4_li_request_new(sb, first_not_zeroed);
3050 	if (!elr)
3051 		return -ENOMEM;
3052 
3053 	mutex_lock(&ext4_li_mtx);
3054 
3055 	if (NULL == ext4_li_info) {
3056 		ret = ext4_li_info_new();
3057 		if (ret)
3058 			goto out;
3059 	}
3060 
3061 	mutex_lock(&ext4_li_info->li_list_mtx);
3062 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3063 	mutex_unlock(&ext4_li_info->li_list_mtx);
3064 
3065 	sbi->s_li_request = elr;
3066 	/*
3067 	 * set elr to NULL here since it has been inserted to
3068 	 * the request_list and the removal and free of it is
3069 	 * handled by ext4_clear_request_list from now on.
3070 	 */
3071 	elr = NULL;
3072 
3073 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3074 		ret = ext4_run_lazyinit_thread();
3075 		if (ret)
3076 			goto out;
3077 	}
3078 out:
3079 	mutex_unlock(&ext4_li_mtx);
3080 	if (ret)
3081 		kfree(elr);
3082 	return ret;
3083 }
3084 
3085 /*
3086  * We do not need to lock anything since this is called on
3087  * module unload.
3088  */
3089 static void ext4_destroy_lazyinit_thread(void)
3090 {
3091 	/*
3092 	 * If thread exited earlier
3093 	 * there's nothing to be done.
3094 	 */
3095 	if (!ext4_li_info || !ext4_lazyinit_task)
3096 		return;
3097 
3098 	kthread_stop(ext4_lazyinit_task);
3099 }
3100 
3101 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3102 				__releases(kernel_lock)
3103 				__acquires(kernel_lock)
3104 {
3105 	char *orig_data = kstrdup(data, GFP_KERNEL);
3106 	struct buffer_head *bh;
3107 	struct ext4_super_block *es = NULL;
3108 	struct ext4_sb_info *sbi;
3109 	ext4_fsblk_t block;
3110 	ext4_fsblk_t sb_block = get_sb_block(&data);
3111 	ext4_fsblk_t logical_sb_block;
3112 	unsigned long offset = 0;
3113 	unsigned long journal_devnum = 0;
3114 	unsigned long def_mount_opts;
3115 	struct inode *root;
3116 	char *cp;
3117 	const char *descr;
3118 	int ret = -ENOMEM;
3119 	int blocksize, clustersize;
3120 	unsigned int db_count;
3121 	unsigned int i;
3122 	int needs_recovery, has_huge_files, has_bigalloc;
3123 	__u64 blocks_count;
3124 	int err;
3125 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3126 	ext4_group_t first_not_zeroed;
3127 
3128 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3129 	if (!sbi)
3130 		goto out_free_orig;
3131 
3132 	sbi->s_blockgroup_lock =
3133 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3134 	if (!sbi->s_blockgroup_lock) {
3135 		kfree(sbi);
3136 		goto out_free_orig;
3137 	}
3138 	sb->s_fs_info = sbi;
3139 	sbi->s_mount_opt = 0;
3140 	sbi->s_resuid = EXT4_DEF_RESUID;
3141 	sbi->s_resgid = EXT4_DEF_RESGID;
3142 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3143 	sbi->s_sb_block = sb_block;
3144 	if (sb->s_bdev->bd_part)
3145 		sbi->s_sectors_written_start =
3146 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3147 
3148 	/* Cleanup superblock name */
3149 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3150 		*cp = '!';
3151 
3152 	ret = -EINVAL;
3153 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3154 	if (!blocksize) {
3155 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3156 		goto out_fail;
3157 	}
3158 
3159 	/*
3160 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3161 	 * block sizes.  We need to calculate the offset from buffer start.
3162 	 */
3163 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3164 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3165 		offset = do_div(logical_sb_block, blocksize);
3166 	} else {
3167 		logical_sb_block = sb_block;
3168 	}
3169 
3170 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3171 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3172 		goto out_fail;
3173 	}
3174 	/*
3175 	 * Note: s_es must be initialized as soon as possible because
3176 	 *       some ext4 macro-instructions depend on its value
3177 	 */
3178 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3179 	sbi->s_es = es;
3180 	sb->s_magic = le16_to_cpu(es->s_magic);
3181 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3182 		goto cantfind_ext4;
3183 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3184 
3185 	/* Set defaults before we parse the mount options */
3186 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3187 	set_opt(sb, INIT_INODE_TABLE);
3188 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3189 		set_opt(sb, DEBUG);
3190 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS) {
3191 		ext4_msg(sb, KERN_WARNING, deprecated_msg, "bsdgroups",
3192 			"2.6.38");
3193 		set_opt(sb, GRPID);
3194 	}
3195 	if (def_mount_opts & EXT4_DEFM_UID16)
3196 		set_opt(sb, NO_UID32);
3197 	/* xattr user namespace & acls are now defaulted on */
3198 #ifdef CONFIG_EXT4_FS_XATTR
3199 	set_opt(sb, XATTR_USER);
3200 #endif
3201 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3202 	set_opt(sb, POSIX_ACL);
3203 #endif
3204 	set_opt(sb, MBLK_IO_SUBMIT);
3205 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3206 		set_opt(sb, JOURNAL_DATA);
3207 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3208 		set_opt(sb, ORDERED_DATA);
3209 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3210 		set_opt(sb, WRITEBACK_DATA);
3211 
3212 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3213 		set_opt(sb, ERRORS_PANIC);
3214 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3215 		set_opt(sb, ERRORS_CONT);
3216 	else
3217 		set_opt(sb, ERRORS_RO);
3218 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3219 		set_opt(sb, BLOCK_VALIDITY);
3220 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3221 		set_opt(sb, DISCARD);
3222 
3223 	sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
3224 	sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
3225 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3226 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3227 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3228 
3229 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3230 		set_opt(sb, BARRIER);
3231 
3232 	/*
3233 	 * enable delayed allocation by default
3234 	 * Use -o nodelalloc to turn it off
3235 	 */
3236 	if (!IS_EXT3_SB(sb) &&
3237 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3238 		set_opt(sb, DELALLOC);
3239 
3240 	/*
3241 	 * set default s_li_wait_mult for lazyinit, for the case there is
3242 	 * no mount option specified.
3243 	 */
3244 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3245 
3246 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3247 			   &journal_devnum, &journal_ioprio, NULL, 0)) {
3248 		ext4_msg(sb, KERN_WARNING,
3249 			 "failed to parse options in superblock: %s",
3250 			 sbi->s_es->s_mount_opts);
3251 	}
3252 	if (!parse_options((char *) data, sb, &journal_devnum,
3253 			   &journal_ioprio, NULL, 0))
3254 		goto failed_mount;
3255 
3256 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3257 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3258 			    "with data=journal disables delayed "
3259 			    "allocation and O_DIRECT support!\n");
3260 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3261 			ext4_msg(sb, KERN_ERR, "can't mount with "
3262 				 "both data=journal and delalloc");
3263 			goto failed_mount;
3264 		}
3265 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3266 			ext4_msg(sb, KERN_ERR, "can't mount with "
3267 				 "both data=journal and delalloc");
3268 			goto failed_mount;
3269 		}
3270 		if (test_opt(sb, DELALLOC))
3271 			clear_opt(sb, DELALLOC);
3272 	}
3273 
3274 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3275 	if (test_opt(sb, DIOREAD_NOLOCK)) {
3276 		if (blocksize < PAGE_SIZE) {
3277 			ext4_msg(sb, KERN_ERR, "can't mount with "
3278 				 "dioread_nolock if block size != PAGE_SIZE");
3279 			goto failed_mount;
3280 		}
3281 	}
3282 
3283 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3284 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3285 
3286 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3287 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3288 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3289 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3290 		ext4_msg(sb, KERN_WARNING,
3291 		       "feature flags set on rev 0 fs, "
3292 		       "running e2fsck is recommended");
3293 
3294 	if (IS_EXT2_SB(sb)) {
3295 		if (ext2_feature_set_ok(sb))
3296 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3297 				 "using the ext4 subsystem");
3298 		else {
3299 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3300 				 "to feature incompatibilities");
3301 			goto failed_mount;
3302 		}
3303 	}
3304 
3305 	if (IS_EXT3_SB(sb)) {
3306 		if (ext3_feature_set_ok(sb))
3307 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3308 				 "using the ext4 subsystem");
3309 		else {
3310 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3311 				 "to feature incompatibilities");
3312 			goto failed_mount;
3313 		}
3314 	}
3315 
3316 	/*
3317 	 * Check feature flags regardless of the revision level, since we
3318 	 * previously didn't change the revision level when setting the flags,
3319 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3320 	 */
3321 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3322 		goto failed_mount;
3323 
3324 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3325 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3326 		ext4_msg(sb, KERN_ERR,
3327 		       "Unsupported filesystem blocksize %d", blocksize);
3328 		goto failed_mount;
3329 	}
3330 
3331 	if (sb->s_blocksize != blocksize) {
3332 		/* Validate the filesystem blocksize */
3333 		if (!sb_set_blocksize(sb, blocksize)) {
3334 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3335 					blocksize);
3336 			goto failed_mount;
3337 		}
3338 
3339 		brelse(bh);
3340 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3341 		offset = do_div(logical_sb_block, blocksize);
3342 		bh = sb_bread(sb, logical_sb_block);
3343 		if (!bh) {
3344 			ext4_msg(sb, KERN_ERR,
3345 			       "Can't read superblock on 2nd try");
3346 			goto failed_mount;
3347 		}
3348 		es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
3349 		sbi->s_es = es;
3350 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3351 			ext4_msg(sb, KERN_ERR,
3352 			       "Magic mismatch, very weird!");
3353 			goto failed_mount;
3354 		}
3355 	}
3356 
3357 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3358 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3359 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3360 						      has_huge_files);
3361 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3362 
3363 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3364 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3365 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3366 	} else {
3367 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3368 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3369 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3370 		    (!is_power_of_2(sbi->s_inode_size)) ||
3371 		    (sbi->s_inode_size > blocksize)) {
3372 			ext4_msg(sb, KERN_ERR,
3373 			       "unsupported inode size: %d",
3374 			       sbi->s_inode_size);
3375 			goto failed_mount;
3376 		}
3377 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3378 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3379 	}
3380 
3381 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3382 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3383 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3384 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3385 		    !is_power_of_2(sbi->s_desc_size)) {
3386 			ext4_msg(sb, KERN_ERR,
3387 			       "unsupported descriptor size %lu",
3388 			       sbi->s_desc_size);
3389 			goto failed_mount;
3390 		}
3391 	} else
3392 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3393 
3394 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3395 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3396 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3397 		goto cantfind_ext4;
3398 
3399 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3400 	if (sbi->s_inodes_per_block == 0)
3401 		goto cantfind_ext4;
3402 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3403 					sbi->s_inodes_per_block;
3404 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3405 	sbi->s_sbh = bh;
3406 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3407 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3408 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3409 
3410 	for (i = 0; i < 4; i++)
3411 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3412 	sbi->s_def_hash_version = es->s_def_hash_version;
3413 	i = le32_to_cpu(es->s_flags);
3414 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3415 		sbi->s_hash_unsigned = 3;
3416 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3417 #ifdef __CHAR_UNSIGNED__
3418 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3419 		sbi->s_hash_unsigned = 3;
3420 #else
3421 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3422 #endif
3423 		sb->s_dirt = 1;
3424 	}
3425 
3426 	/* Handle clustersize */
3427 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3428 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3429 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3430 	if (has_bigalloc) {
3431 		if (clustersize < blocksize) {
3432 			ext4_msg(sb, KERN_ERR,
3433 				 "cluster size (%d) smaller than "
3434 				 "block size (%d)", clustersize, blocksize);
3435 			goto failed_mount;
3436 		}
3437 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3438 			le32_to_cpu(es->s_log_block_size);
3439 		sbi->s_clusters_per_group =
3440 			le32_to_cpu(es->s_clusters_per_group);
3441 		if (sbi->s_clusters_per_group > blocksize * 8) {
3442 			ext4_msg(sb, KERN_ERR,
3443 				 "#clusters per group too big: %lu",
3444 				 sbi->s_clusters_per_group);
3445 			goto failed_mount;
3446 		}
3447 		if (sbi->s_blocks_per_group !=
3448 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3449 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3450 				 "clusters per group (%lu) inconsistent",
3451 				 sbi->s_blocks_per_group,
3452 				 sbi->s_clusters_per_group);
3453 			goto failed_mount;
3454 		}
3455 	} else {
3456 		if (clustersize != blocksize) {
3457 			ext4_warning(sb, "fragment/cluster size (%d) != "
3458 				     "block size (%d)", clustersize,
3459 				     blocksize);
3460 			clustersize = blocksize;
3461 		}
3462 		if (sbi->s_blocks_per_group > blocksize * 8) {
3463 			ext4_msg(sb, KERN_ERR,
3464 				 "#blocks per group too big: %lu",
3465 				 sbi->s_blocks_per_group);
3466 			goto failed_mount;
3467 		}
3468 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3469 		sbi->s_cluster_bits = 0;
3470 	}
3471 	sbi->s_cluster_ratio = clustersize / blocksize;
3472 
3473 	if (sbi->s_inodes_per_group > blocksize * 8) {
3474 		ext4_msg(sb, KERN_ERR,
3475 		       "#inodes per group too big: %lu",
3476 		       sbi->s_inodes_per_group);
3477 		goto failed_mount;
3478 	}
3479 
3480 	/*
3481 	 * Test whether we have more sectors than will fit in sector_t,
3482 	 * and whether the max offset is addressable by the page cache.
3483 	 */
3484 	err = generic_check_addressable(sb->s_blocksize_bits,
3485 					ext4_blocks_count(es));
3486 	if (err) {
3487 		ext4_msg(sb, KERN_ERR, "filesystem"
3488 			 " too large to mount safely on this system");
3489 		if (sizeof(sector_t) < 8)
3490 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3491 		ret = err;
3492 		goto failed_mount;
3493 	}
3494 
3495 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3496 		goto cantfind_ext4;
3497 
3498 	/* check blocks count against device size */
3499 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3500 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3501 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3502 		       "exceeds size of device (%llu blocks)",
3503 		       ext4_blocks_count(es), blocks_count);
3504 		goto failed_mount;
3505 	}
3506 
3507 	/*
3508 	 * It makes no sense for the first data block to be beyond the end
3509 	 * of the filesystem.
3510 	 */
3511 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3512                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
3513 			 "block %u is beyond end of filesystem (%llu)",
3514 			 le32_to_cpu(es->s_first_data_block),
3515 			 ext4_blocks_count(es));
3516 		goto failed_mount;
3517 	}
3518 	blocks_count = (ext4_blocks_count(es) -
3519 			le32_to_cpu(es->s_first_data_block) +
3520 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3521 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3522 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3523 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3524 		       "(block count %llu, first data block %u, "
3525 		       "blocks per group %lu)", sbi->s_groups_count,
3526 		       ext4_blocks_count(es),
3527 		       le32_to_cpu(es->s_first_data_block),
3528 		       EXT4_BLOCKS_PER_GROUP(sb));
3529 		goto failed_mount;
3530 	}
3531 	sbi->s_groups_count = blocks_count;
3532 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3533 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3534 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3535 		   EXT4_DESC_PER_BLOCK(sb);
3536 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3537 					  sizeof(struct buffer_head *),
3538 					  GFP_KERNEL);
3539 	if (sbi->s_group_desc == NULL) {
3540 		ext4_msg(sb, KERN_ERR, "not enough memory");
3541 		goto failed_mount;
3542 	}
3543 
3544 	if (ext4_proc_root)
3545 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3546 
3547 	bgl_lock_init(sbi->s_blockgroup_lock);
3548 
3549 	for (i = 0; i < db_count; i++) {
3550 		block = descriptor_loc(sb, logical_sb_block, i);
3551 		sbi->s_group_desc[i] = sb_bread(sb, block);
3552 		if (!sbi->s_group_desc[i]) {
3553 			ext4_msg(sb, KERN_ERR,
3554 			       "can't read group descriptor %d", i);
3555 			db_count = i;
3556 			goto failed_mount2;
3557 		}
3558 	}
3559 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3560 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3561 		goto failed_mount2;
3562 	}
3563 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3564 		if (!ext4_fill_flex_info(sb)) {
3565 			ext4_msg(sb, KERN_ERR,
3566 			       "unable to initialize "
3567 			       "flex_bg meta info!");
3568 			goto failed_mount2;
3569 		}
3570 
3571 	sbi->s_gdb_count = db_count;
3572 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3573 	spin_lock_init(&sbi->s_next_gen_lock);
3574 
3575 	init_timer(&sbi->s_err_report);
3576 	sbi->s_err_report.function = print_daily_error_info;
3577 	sbi->s_err_report.data = (unsigned long) sb;
3578 
3579 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3580 			ext4_count_free_clusters(sb));
3581 	if (!err) {
3582 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3583 				ext4_count_free_inodes(sb));
3584 	}
3585 	if (!err) {
3586 		err = percpu_counter_init(&sbi->s_dirs_counter,
3587 				ext4_count_dirs(sb));
3588 	}
3589 	if (!err) {
3590 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3591 	}
3592 	if (err) {
3593 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3594 		goto failed_mount3;
3595 	}
3596 
3597 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3598 	sbi->s_max_writeback_mb_bump = 128;
3599 
3600 	/*
3601 	 * set up enough so that it can read an inode
3602 	 */
3603 	if (!test_opt(sb, NOLOAD) &&
3604 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3605 		sb->s_op = &ext4_sops;
3606 	else
3607 		sb->s_op = &ext4_nojournal_sops;
3608 	sb->s_export_op = &ext4_export_ops;
3609 	sb->s_xattr = ext4_xattr_handlers;
3610 #ifdef CONFIG_QUOTA
3611 	sb->s_qcop = &ext4_qctl_operations;
3612 	sb->dq_op = &ext4_quota_operations;
3613 #endif
3614 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3615 
3616 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3617 	mutex_init(&sbi->s_orphan_lock);
3618 	sbi->s_resize_flags = 0;
3619 
3620 	sb->s_root = NULL;
3621 
3622 	needs_recovery = (es->s_last_orphan != 0 ||
3623 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3624 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3625 
3626 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3627 	    !(sb->s_flags & MS_RDONLY))
3628 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3629 			goto failed_mount3;
3630 
3631 	/*
3632 	 * The first inode we look at is the journal inode.  Don't try
3633 	 * root first: it may be modified in the journal!
3634 	 */
3635 	if (!test_opt(sb, NOLOAD) &&
3636 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3637 		if (ext4_load_journal(sb, es, journal_devnum))
3638 			goto failed_mount3;
3639 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3640 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3641 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3642 		       "suppressed and not mounted read-only");
3643 		goto failed_mount_wq;
3644 	} else {
3645 		clear_opt(sb, DATA_FLAGS);
3646 		sbi->s_journal = NULL;
3647 		needs_recovery = 0;
3648 		goto no_journal;
3649 	}
3650 
3651 	if (ext4_blocks_count(es) > 0xffffffffULL &&
3652 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3653 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3654 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3655 		goto failed_mount_wq;
3656 	}
3657 
3658 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3659 		jbd2_journal_set_features(sbi->s_journal,
3660 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3661 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3662 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3663 		jbd2_journal_set_features(sbi->s_journal,
3664 				JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
3665 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3666 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3667 	} else {
3668 		jbd2_journal_clear_features(sbi->s_journal,
3669 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3670 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3671 	}
3672 
3673 	/* We have now updated the journal if required, so we can
3674 	 * validate the data journaling mode. */
3675 	switch (test_opt(sb, DATA_FLAGS)) {
3676 	case 0:
3677 		/* No mode set, assume a default based on the journal
3678 		 * capabilities: ORDERED_DATA if the journal can
3679 		 * cope, else JOURNAL_DATA
3680 		 */
3681 		if (jbd2_journal_check_available_features
3682 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3683 			set_opt(sb, ORDERED_DATA);
3684 		else
3685 			set_opt(sb, JOURNAL_DATA);
3686 		break;
3687 
3688 	case EXT4_MOUNT_ORDERED_DATA:
3689 	case EXT4_MOUNT_WRITEBACK_DATA:
3690 		if (!jbd2_journal_check_available_features
3691 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3692 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3693 			       "requested data journaling mode");
3694 			goto failed_mount_wq;
3695 		}
3696 	default:
3697 		break;
3698 	}
3699 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3700 
3701 	/*
3702 	 * The journal may have updated the bg summary counts, so we
3703 	 * need to update the global counters.
3704 	 */
3705 	percpu_counter_set(&sbi->s_freeclusters_counter,
3706 			   ext4_count_free_clusters(sb));
3707 	percpu_counter_set(&sbi->s_freeinodes_counter,
3708 			   ext4_count_free_inodes(sb));
3709 	percpu_counter_set(&sbi->s_dirs_counter,
3710 			   ext4_count_dirs(sb));
3711 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3712 
3713 no_journal:
3714 	/*
3715 	 * The maximum number of concurrent works can be high and
3716 	 * concurrency isn't really necessary.  Limit it to 1.
3717 	 */
3718 	EXT4_SB(sb)->dio_unwritten_wq =
3719 		alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3720 	if (!EXT4_SB(sb)->dio_unwritten_wq) {
3721 		printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3722 		goto failed_mount_wq;
3723 	}
3724 
3725 	/*
3726 	 * The jbd2_journal_load will have done any necessary log recovery,
3727 	 * so we can safely mount the rest of the filesystem now.
3728 	 */
3729 
3730 	root = ext4_iget(sb, EXT4_ROOT_INO);
3731 	if (IS_ERR(root)) {
3732 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3733 		ret = PTR_ERR(root);
3734 		root = NULL;
3735 		goto failed_mount4;
3736 	}
3737 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3738 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3739 		goto failed_mount4;
3740 	}
3741 	sb->s_root = d_alloc_root(root);
3742 	if (!sb->s_root) {
3743 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3744 		ret = -ENOMEM;
3745 		goto failed_mount4;
3746 	}
3747 
3748 	ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
3749 
3750 	/* determine the minimum size of new large inodes, if present */
3751 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3752 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3753 						     EXT4_GOOD_OLD_INODE_SIZE;
3754 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3755 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3756 			if (sbi->s_want_extra_isize <
3757 			    le16_to_cpu(es->s_want_extra_isize))
3758 				sbi->s_want_extra_isize =
3759 					le16_to_cpu(es->s_want_extra_isize);
3760 			if (sbi->s_want_extra_isize <
3761 			    le16_to_cpu(es->s_min_extra_isize))
3762 				sbi->s_want_extra_isize =
3763 					le16_to_cpu(es->s_min_extra_isize);
3764 		}
3765 	}
3766 	/* Check if enough inode space is available */
3767 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3768 							sbi->s_inode_size) {
3769 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3770 						       EXT4_GOOD_OLD_INODE_SIZE;
3771 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
3772 			 "available");
3773 	}
3774 
3775 	err = ext4_setup_system_zone(sb);
3776 	if (err) {
3777 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
3778 			 "zone (%d)", err);
3779 		goto failed_mount4;
3780 	}
3781 
3782 	ext4_ext_init(sb);
3783 	err = ext4_mb_init(sb, needs_recovery);
3784 	if (err) {
3785 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3786 			 err);
3787 		goto failed_mount5;
3788 	}
3789 
3790 	err = ext4_register_li_request(sb, first_not_zeroed);
3791 	if (err)
3792 		goto failed_mount6;
3793 
3794 	sbi->s_kobj.kset = ext4_kset;
3795 	init_completion(&sbi->s_kobj_unregister);
3796 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3797 				   "%s", sb->s_id);
3798 	if (err)
3799 		goto failed_mount7;
3800 
3801 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3802 	ext4_orphan_cleanup(sb, es);
3803 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3804 	if (needs_recovery) {
3805 		ext4_msg(sb, KERN_INFO, "recovery complete");
3806 		ext4_mark_recovery_complete(sb, es);
3807 	}
3808 	if (EXT4_SB(sb)->s_journal) {
3809 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3810 			descr = " journalled data mode";
3811 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3812 			descr = " ordered data mode";
3813 		else
3814 			descr = " writeback data mode";
3815 	} else
3816 		descr = "out journal";
3817 
3818 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3819 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3820 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3821 
3822 	if (es->s_error_count)
3823 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3824 
3825 	kfree(orig_data);
3826 	return 0;
3827 
3828 cantfind_ext4:
3829 	if (!silent)
3830 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3831 	goto failed_mount;
3832 
3833 failed_mount7:
3834 	ext4_unregister_li_request(sb);
3835 failed_mount6:
3836 	ext4_ext_release(sb);
3837 failed_mount5:
3838 	ext4_mb_release(sb);
3839 	ext4_release_system_zone(sb);
3840 failed_mount4:
3841 	iput(root);
3842 	sb->s_root = NULL;
3843 	ext4_msg(sb, KERN_ERR, "mount failed");
3844 	destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
3845 failed_mount_wq:
3846 	if (sbi->s_journal) {
3847 		jbd2_journal_destroy(sbi->s_journal);
3848 		sbi->s_journal = NULL;
3849 	}
3850 failed_mount3:
3851 	del_timer(&sbi->s_err_report);
3852 	if (sbi->s_flex_groups)
3853 		ext4_kvfree(sbi->s_flex_groups);
3854 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
3855 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
3856 	percpu_counter_destroy(&sbi->s_dirs_counter);
3857 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
3858 	if (sbi->s_mmp_tsk)
3859 		kthread_stop(sbi->s_mmp_tsk);
3860 failed_mount2:
3861 	for (i = 0; i < db_count; i++)
3862 		brelse(sbi->s_group_desc[i]);
3863 	ext4_kvfree(sbi->s_group_desc);
3864 failed_mount:
3865 	if (sbi->s_proc) {
3866 		remove_proc_entry(sb->s_id, ext4_proc_root);
3867 	}
3868 #ifdef CONFIG_QUOTA
3869 	for (i = 0; i < MAXQUOTAS; i++)
3870 		kfree(sbi->s_qf_names[i]);
3871 #endif
3872 	ext4_blkdev_remove(sbi);
3873 	brelse(bh);
3874 out_fail:
3875 	sb->s_fs_info = NULL;
3876 	kfree(sbi->s_blockgroup_lock);
3877 	kfree(sbi);
3878 out_free_orig:
3879 	kfree(orig_data);
3880 	return ret;
3881 }
3882 
3883 /*
3884  * Setup any per-fs journal parameters now.  We'll do this both on
3885  * initial mount, once the journal has been initialised but before we've
3886  * done any recovery; and again on any subsequent remount.
3887  */
3888 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
3889 {
3890 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3891 
3892 	journal->j_commit_interval = sbi->s_commit_interval;
3893 	journal->j_min_batch_time = sbi->s_min_batch_time;
3894 	journal->j_max_batch_time = sbi->s_max_batch_time;
3895 
3896 	write_lock(&journal->j_state_lock);
3897 	if (test_opt(sb, BARRIER))
3898 		journal->j_flags |= JBD2_BARRIER;
3899 	else
3900 		journal->j_flags &= ~JBD2_BARRIER;
3901 	if (test_opt(sb, DATA_ERR_ABORT))
3902 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
3903 	else
3904 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
3905 	write_unlock(&journal->j_state_lock);
3906 }
3907 
3908 static journal_t *ext4_get_journal(struct super_block *sb,
3909 				   unsigned int journal_inum)
3910 {
3911 	struct inode *journal_inode;
3912 	journal_t *journal;
3913 
3914 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3915 
3916 	/* First, test for the existence of a valid inode on disk.  Bad
3917 	 * things happen if we iget() an unused inode, as the subsequent
3918 	 * iput() will try to delete it. */
3919 
3920 	journal_inode = ext4_iget(sb, journal_inum);
3921 	if (IS_ERR(journal_inode)) {
3922 		ext4_msg(sb, KERN_ERR, "no journal found");
3923 		return NULL;
3924 	}
3925 	if (!journal_inode->i_nlink) {
3926 		make_bad_inode(journal_inode);
3927 		iput(journal_inode);
3928 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3929 		return NULL;
3930 	}
3931 
3932 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3933 		  journal_inode, journal_inode->i_size);
3934 	if (!S_ISREG(journal_inode->i_mode)) {
3935 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
3936 		iput(journal_inode);
3937 		return NULL;
3938 	}
3939 
3940 	journal = jbd2_journal_init_inode(journal_inode);
3941 	if (!journal) {
3942 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3943 		iput(journal_inode);
3944 		return NULL;
3945 	}
3946 	journal->j_private = sb;
3947 	ext4_init_journal_params(sb, journal);
3948 	return journal;
3949 }
3950 
3951 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3952 				       dev_t j_dev)
3953 {
3954 	struct buffer_head *bh;
3955 	journal_t *journal;
3956 	ext4_fsblk_t start;
3957 	ext4_fsblk_t len;
3958 	int hblock, blocksize;
3959 	ext4_fsblk_t sb_block;
3960 	unsigned long offset;
3961 	struct ext4_super_block *es;
3962 	struct block_device *bdev;
3963 
3964 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3965 
3966 	bdev = ext4_blkdev_get(j_dev, sb);
3967 	if (bdev == NULL)
3968 		return NULL;
3969 
3970 	blocksize = sb->s_blocksize;
3971 	hblock = bdev_logical_block_size(bdev);
3972 	if (blocksize < hblock) {
3973 		ext4_msg(sb, KERN_ERR,
3974 			"blocksize too small for journal device");
3975 		goto out_bdev;
3976 	}
3977 
3978 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3979 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3980 	set_blocksize(bdev, blocksize);
3981 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
3982 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3983 		       "external journal");
3984 		goto out_bdev;
3985 	}
3986 
3987 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3988 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3989 	    !(le32_to_cpu(es->s_feature_incompat) &
3990 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3991 		ext4_msg(sb, KERN_ERR, "external journal has "
3992 					"bad superblock");
3993 		brelse(bh);
3994 		goto out_bdev;
3995 	}
3996 
3997 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3998 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3999 		brelse(bh);
4000 		goto out_bdev;
4001 	}
4002 
4003 	len = ext4_blocks_count(es);
4004 	start = sb_block + 1;
4005 	brelse(bh);	/* we're done with the superblock */
4006 
4007 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4008 					start, len, blocksize);
4009 	if (!journal) {
4010 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4011 		goto out_bdev;
4012 	}
4013 	journal->j_private = sb;
4014 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
4015 	wait_on_buffer(journal->j_sb_buffer);
4016 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4017 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4018 		goto out_journal;
4019 	}
4020 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4021 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4022 					"user (unsupported) - %d",
4023 			be32_to_cpu(journal->j_superblock->s_nr_users));
4024 		goto out_journal;
4025 	}
4026 	EXT4_SB(sb)->journal_bdev = bdev;
4027 	ext4_init_journal_params(sb, journal);
4028 	return journal;
4029 
4030 out_journal:
4031 	jbd2_journal_destroy(journal);
4032 out_bdev:
4033 	ext4_blkdev_put(bdev);
4034 	return NULL;
4035 }
4036 
4037 static int ext4_load_journal(struct super_block *sb,
4038 			     struct ext4_super_block *es,
4039 			     unsigned long journal_devnum)
4040 {
4041 	journal_t *journal;
4042 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4043 	dev_t journal_dev;
4044 	int err = 0;
4045 	int really_read_only;
4046 
4047 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4048 
4049 	if (journal_devnum &&
4050 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4051 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4052 			"numbers have changed");
4053 		journal_dev = new_decode_dev(journal_devnum);
4054 	} else
4055 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4056 
4057 	really_read_only = bdev_read_only(sb->s_bdev);
4058 
4059 	/*
4060 	 * Are we loading a blank journal or performing recovery after a
4061 	 * crash?  For recovery, we need to check in advance whether we
4062 	 * can get read-write access to the device.
4063 	 */
4064 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4065 		if (sb->s_flags & MS_RDONLY) {
4066 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4067 					"required on readonly filesystem");
4068 			if (really_read_only) {
4069 				ext4_msg(sb, KERN_ERR, "write access "
4070 					"unavailable, cannot proceed");
4071 				return -EROFS;
4072 			}
4073 			ext4_msg(sb, KERN_INFO, "write access will "
4074 			       "be enabled during recovery");
4075 		}
4076 	}
4077 
4078 	if (journal_inum && journal_dev) {
4079 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4080 		       "and inode journals!");
4081 		return -EINVAL;
4082 	}
4083 
4084 	if (journal_inum) {
4085 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4086 			return -EINVAL;
4087 	} else {
4088 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4089 			return -EINVAL;
4090 	}
4091 
4092 	if (!(journal->j_flags & JBD2_BARRIER))
4093 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4094 
4095 	if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
4096 		err = jbd2_journal_update_format(journal);
4097 		if (err)  {
4098 			ext4_msg(sb, KERN_ERR, "error updating journal");
4099 			jbd2_journal_destroy(journal);
4100 			return err;
4101 		}
4102 	}
4103 
4104 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4105 		err = jbd2_journal_wipe(journal, !really_read_only);
4106 	if (!err) {
4107 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4108 		if (save)
4109 			memcpy(save, ((char *) es) +
4110 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4111 		err = jbd2_journal_load(journal);
4112 		if (save)
4113 			memcpy(((char *) es) + EXT4_S_ERR_START,
4114 			       save, EXT4_S_ERR_LEN);
4115 		kfree(save);
4116 	}
4117 
4118 	if (err) {
4119 		ext4_msg(sb, KERN_ERR, "error loading journal");
4120 		jbd2_journal_destroy(journal);
4121 		return err;
4122 	}
4123 
4124 	EXT4_SB(sb)->s_journal = journal;
4125 	ext4_clear_journal_err(sb, es);
4126 
4127 	if (!really_read_only && journal_devnum &&
4128 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4129 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4130 
4131 		/* Make sure we flush the recovery flag to disk. */
4132 		ext4_commit_super(sb, 1);
4133 	}
4134 
4135 	return 0;
4136 }
4137 
4138 static int ext4_commit_super(struct super_block *sb, int sync)
4139 {
4140 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4141 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4142 	int error = 0;
4143 
4144 	if (!sbh || block_device_ejected(sb))
4145 		return error;
4146 	if (buffer_write_io_error(sbh)) {
4147 		/*
4148 		 * Oh, dear.  A previous attempt to write the
4149 		 * superblock failed.  This could happen because the
4150 		 * USB device was yanked out.  Or it could happen to
4151 		 * be a transient write error and maybe the block will
4152 		 * be remapped.  Nothing we can do but to retry the
4153 		 * write and hope for the best.
4154 		 */
4155 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4156 		       "superblock detected");
4157 		clear_buffer_write_io_error(sbh);
4158 		set_buffer_uptodate(sbh);
4159 	}
4160 	/*
4161 	 * If the file system is mounted read-only, don't update the
4162 	 * superblock write time.  This avoids updating the superblock
4163 	 * write time when we are mounting the root file system
4164 	 * read/only but we need to replay the journal; at that point,
4165 	 * for people who are east of GMT and who make their clock
4166 	 * tick in localtime for Windows bug-for-bug compatibility,
4167 	 * the clock is set in the future, and this will cause e2fsck
4168 	 * to complain and force a full file system check.
4169 	 */
4170 	if (!(sb->s_flags & MS_RDONLY))
4171 		es->s_wtime = cpu_to_le32(get_seconds());
4172 	if (sb->s_bdev->bd_part)
4173 		es->s_kbytes_written =
4174 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4175 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4176 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4177 	else
4178 		es->s_kbytes_written =
4179 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4180 	ext4_free_blocks_count_set(es,
4181 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4182 				&EXT4_SB(sb)->s_freeclusters_counter)));
4183 	es->s_free_inodes_count =
4184 		cpu_to_le32(percpu_counter_sum_positive(
4185 				&EXT4_SB(sb)->s_freeinodes_counter));
4186 	sb->s_dirt = 0;
4187 	BUFFER_TRACE(sbh, "marking dirty");
4188 	mark_buffer_dirty(sbh);
4189 	if (sync) {
4190 		error = sync_dirty_buffer(sbh);
4191 		if (error)
4192 			return error;
4193 
4194 		error = buffer_write_io_error(sbh);
4195 		if (error) {
4196 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4197 			       "superblock");
4198 			clear_buffer_write_io_error(sbh);
4199 			set_buffer_uptodate(sbh);
4200 		}
4201 	}
4202 	return error;
4203 }
4204 
4205 /*
4206  * Have we just finished recovery?  If so, and if we are mounting (or
4207  * remounting) the filesystem readonly, then we will end up with a
4208  * consistent fs on disk.  Record that fact.
4209  */
4210 static void ext4_mark_recovery_complete(struct super_block *sb,
4211 					struct ext4_super_block *es)
4212 {
4213 	journal_t *journal = EXT4_SB(sb)->s_journal;
4214 
4215 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4216 		BUG_ON(journal != NULL);
4217 		return;
4218 	}
4219 	jbd2_journal_lock_updates(journal);
4220 	if (jbd2_journal_flush(journal) < 0)
4221 		goto out;
4222 
4223 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4224 	    sb->s_flags & MS_RDONLY) {
4225 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4226 		ext4_commit_super(sb, 1);
4227 	}
4228 
4229 out:
4230 	jbd2_journal_unlock_updates(journal);
4231 }
4232 
4233 /*
4234  * If we are mounting (or read-write remounting) a filesystem whose journal
4235  * has recorded an error from a previous lifetime, move that error to the
4236  * main filesystem now.
4237  */
4238 static void ext4_clear_journal_err(struct super_block *sb,
4239 				   struct ext4_super_block *es)
4240 {
4241 	journal_t *journal;
4242 	int j_errno;
4243 	const char *errstr;
4244 
4245 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4246 
4247 	journal = EXT4_SB(sb)->s_journal;
4248 
4249 	/*
4250 	 * Now check for any error status which may have been recorded in the
4251 	 * journal by a prior ext4_error() or ext4_abort()
4252 	 */
4253 
4254 	j_errno = jbd2_journal_errno(journal);
4255 	if (j_errno) {
4256 		char nbuf[16];
4257 
4258 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4259 		ext4_warning(sb, "Filesystem error recorded "
4260 			     "from previous mount: %s", errstr);
4261 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4262 
4263 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4264 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4265 		ext4_commit_super(sb, 1);
4266 
4267 		jbd2_journal_clear_err(journal);
4268 	}
4269 }
4270 
4271 /*
4272  * Force the running and committing transactions to commit,
4273  * and wait on the commit.
4274  */
4275 int ext4_force_commit(struct super_block *sb)
4276 {
4277 	journal_t *journal;
4278 	int ret = 0;
4279 
4280 	if (sb->s_flags & MS_RDONLY)
4281 		return 0;
4282 
4283 	journal = EXT4_SB(sb)->s_journal;
4284 	if (journal) {
4285 		vfs_check_frozen(sb, SB_FREEZE_TRANS);
4286 		ret = ext4_journal_force_commit(journal);
4287 	}
4288 
4289 	return ret;
4290 }
4291 
4292 static void ext4_write_super(struct super_block *sb)
4293 {
4294 	lock_super(sb);
4295 	ext4_commit_super(sb, 1);
4296 	unlock_super(sb);
4297 }
4298 
4299 static int ext4_sync_fs(struct super_block *sb, int wait)
4300 {
4301 	int ret = 0;
4302 	tid_t target;
4303 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4304 
4305 	trace_ext4_sync_fs(sb, wait);
4306 	flush_workqueue(sbi->dio_unwritten_wq);
4307 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4308 		if (wait)
4309 			jbd2_log_wait_commit(sbi->s_journal, target);
4310 	}
4311 	return ret;
4312 }
4313 
4314 /*
4315  * LVM calls this function before a (read-only) snapshot is created.  This
4316  * gives us a chance to flush the journal completely and mark the fs clean.
4317  *
4318  * Note that only this function cannot bring a filesystem to be in a clean
4319  * state independently, because ext4 prevents a new handle from being started
4320  * by @sb->s_frozen, which stays in an upper layer.  It thus needs help from
4321  * the upper layer.
4322  */
4323 static int ext4_freeze(struct super_block *sb)
4324 {
4325 	int error = 0;
4326 	journal_t *journal;
4327 
4328 	if (sb->s_flags & MS_RDONLY)
4329 		return 0;
4330 
4331 	journal = EXT4_SB(sb)->s_journal;
4332 
4333 	/* Now we set up the journal barrier. */
4334 	jbd2_journal_lock_updates(journal);
4335 
4336 	/*
4337 	 * Don't clear the needs_recovery flag if we failed to flush
4338 	 * the journal.
4339 	 */
4340 	error = jbd2_journal_flush(journal);
4341 	if (error < 0)
4342 		goto out;
4343 
4344 	/* Journal blocked and flushed, clear needs_recovery flag. */
4345 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4346 	error = ext4_commit_super(sb, 1);
4347 out:
4348 	/* we rely on s_frozen to stop further updates */
4349 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4350 	return error;
4351 }
4352 
4353 /*
4354  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4355  * flag here, even though the filesystem is not technically dirty yet.
4356  */
4357 static int ext4_unfreeze(struct super_block *sb)
4358 {
4359 	if (sb->s_flags & MS_RDONLY)
4360 		return 0;
4361 
4362 	lock_super(sb);
4363 	/* Reset the needs_recovery flag before the fs is unlocked. */
4364 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4365 	ext4_commit_super(sb, 1);
4366 	unlock_super(sb);
4367 	return 0;
4368 }
4369 
4370 /*
4371  * Structure to save mount options for ext4_remount's benefit
4372  */
4373 struct ext4_mount_options {
4374 	unsigned long s_mount_opt;
4375 	unsigned long s_mount_opt2;
4376 	uid_t s_resuid;
4377 	gid_t s_resgid;
4378 	unsigned long s_commit_interval;
4379 	u32 s_min_batch_time, s_max_batch_time;
4380 #ifdef CONFIG_QUOTA
4381 	int s_jquota_fmt;
4382 	char *s_qf_names[MAXQUOTAS];
4383 #endif
4384 };
4385 
4386 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4387 {
4388 	struct ext4_super_block *es;
4389 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4390 	ext4_fsblk_t n_blocks_count = 0;
4391 	unsigned long old_sb_flags;
4392 	struct ext4_mount_options old_opts;
4393 	int enable_quota = 0;
4394 	ext4_group_t g;
4395 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4396 	int err = 0;
4397 #ifdef CONFIG_QUOTA
4398 	int i;
4399 #endif
4400 	char *orig_data = kstrdup(data, GFP_KERNEL);
4401 
4402 	/* Store the original options */
4403 	lock_super(sb);
4404 	old_sb_flags = sb->s_flags;
4405 	old_opts.s_mount_opt = sbi->s_mount_opt;
4406 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4407 	old_opts.s_resuid = sbi->s_resuid;
4408 	old_opts.s_resgid = sbi->s_resgid;
4409 	old_opts.s_commit_interval = sbi->s_commit_interval;
4410 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4411 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4412 #ifdef CONFIG_QUOTA
4413 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4414 	for (i = 0; i < MAXQUOTAS; i++)
4415 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4416 #endif
4417 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4418 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4419 
4420 	/*
4421 	 * Allow the "check" option to be passed as a remount option.
4422 	 */
4423 	if (!parse_options(data, sb, NULL, &journal_ioprio,
4424 			   &n_blocks_count, 1)) {
4425 		err = -EINVAL;
4426 		goto restore_opts;
4427 	}
4428 
4429 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4430 		ext4_abort(sb, "Abort forced by user");
4431 
4432 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4433 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4434 
4435 	es = sbi->s_es;
4436 
4437 	if (sbi->s_journal) {
4438 		ext4_init_journal_params(sb, sbi->s_journal);
4439 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4440 	}
4441 
4442 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
4443 		n_blocks_count > ext4_blocks_count(es)) {
4444 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4445 			err = -EROFS;
4446 			goto restore_opts;
4447 		}
4448 
4449 		if (*flags & MS_RDONLY) {
4450 			err = dquot_suspend(sb, -1);
4451 			if (err < 0)
4452 				goto restore_opts;
4453 
4454 			/*
4455 			 * First of all, the unconditional stuff we have to do
4456 			 * to disable replay of the journal when we next remount
4457 			 */
4458 			sb->s_flags |= MS_RDONLY;
4459 
4460 			/*
4461 			 * OK, test if we are remounting a valid rw partition
4462 			 * readonly, and if so set the rdonly flag and then
4463 			 * mark the partition as valid again.
4464 			 */
4465 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4466 			    (sbi->s_mount_state & EXT4_VALID_FS))
4467 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4468 
4469 			if (sbi->s_journal)
4470 				ext4_mark_recovery_complete(sb, es);
4471 		} else {
4472 			/* Make sure we can mount this feature set readwrite */
4473 			if (!ext4_feature_set_ok(sb, 0)) {
4474 				err = -EROFS;
4475 				goto restore_opts;
4476 			}
4477 			/*
4478 			 * Make sure the group descriptor checksums
4479 			 * are sane.  If they aren't, refuse to remount r/w.
4480 			 */
4481 			for (g = 0; g < sbi->s_groups_count; g++) {
4482 				struct ext4_group_desc *gdp =
4483 					ext4_get_group_desc(sb, g, NULL);
4484 
4485 				if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
4486 					ext4_msg(sb, KERN_ERR,
4487 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4488 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4489 					       le16_to_cpu(gdp->bg_checksum));
4490 					err = -EINVAL;
4491 					goto restore_opts;
4492 				}
4493 			}
4494 
4495 			/*
4496 			 * If we have an unprocessed orphan list hanging
4497 			 * around from a previously readonly bdev mount,
4498 			 * require a full umount/remount for now.
4499 			 */
4500 			if (es->s_last_orphan) {
4501 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4502 				       "remount RDWR because of unprocessed "
4503 				       "orphan inode list.  Please "
4504 				       "umount/remount instead");
4505 				err = -EINVAL;
4506 				goto restore_opts;
4507 			}
4508 
4509 			/*
4510 			 * Mounting a RDONLY partition read-write, so reread
4511 			 * and store the current valid flag.  (It may have
4512 			 * been changed by e2fsck since we originally mounted
4513 			 * the partition.)
4514 			 */
4515 			if (sbi->s_journal)
4516 				ext4_clear_journal_err(sb, es);
4517 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4518 			if ((err = ext4_group_extend(sb, es, n_blocks_count)))
4519 				goto restore_opts;
4520 			if (!ext4_setup_super(sb, es, 0))
4521 				sb->s_flags &= ~MS_RDONLY;
4522 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4523 						     EXT4_FEATURE_INCOMPAT_MMP))
4524 				if (ext4_multi_mount_protect(sb,
4525 						le64_to_cpu(es->s_mmp_block))) {
4526 					err = -EROFS;
4527 					goto restore_opts;
4528 				}
4529 			enable_quota = 1;
4530 		}
4531 	}
4532 
4533 	/*
4534 	 * Reinitialize lazy itable initialization thread based on
4535 	 * current settings
4536 	 */
4537 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4538 		ext4_unregister_li_request(sb);
4539 	else {
4540 		ext4_group_t first_not_zeroed;
4541 		first_not_zeroed = ext4_has_uninit_itable(sb);
4542 		ext4_register_li_request(sb, first_not_zeroed);
4543 	}
4544 
4545 	ext4_setup_system_zone(sb);
4546 	if (sbi->s_journal == NULL)
4547 		ext4_commit_super(sb, 1);
4548 
4549 #ifdef CONFIG_QUOTA
4550 	/* Release old quota file names */
4551 	for (i = 0; i < MAXQUOTAS; i++)
4552 		if (old_opts.s_qf_names[i] &&
4553 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4554 			kfree(old_opts.s_qf_names[i]);
4555 #endif
4556 	unlock_super(sb);
4557 	if (enable_quota)
4558 		dquot_resume(sb, -1);
4559 
4560 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4561 	kfree(orig_data);
4562 	return 0;
4563 
4564 restore_opts:
4565 	sb->s_flags = old_sb_flags;
4566 	sbi->s_mount_opt = old_opts.s_mount_opt;
4567 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4568 	sbi->s_resuid = old_opts.s_resuid;
4569 	sbi->s_resgid = old_opts.s_resgid;
4570 	sbi->s_commit_interval = old_opts.s_commit_interval;
4571 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4572 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4573 #ifdef CONFIG_QUOTA
4574 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4575 	for (i = 0; i < MAXQUOTAS; i++) {
4576 		if (sbi->s_qf_names[i] &&
4577 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4578 			kfree(sbi->s_qf_names[i]);
4579 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4580 	}
4581 #endif
4582 	unlock_super(sb);
4583 	kfree(orig_data);
4584 	return err;
4585 }
4586 
4587 /*
4588  * Note: calculating the overhead so we can be compatible with
4589  * historical BSD practice is quite difficult in the face of
4590  * clusters/bigalloc.  This is because multiple metadata blocks from
4591  * different block group can end up in the same allocation cluster.
4592  * Calculating the exact overhead in the face of clustered allocation
4593  * requires either O(all block bitmaps) in memory or O(number of block
4594  * groups**2) in time.  We will still calculate the superblock for
4595  * older file systems --- and if we come across with a bigalloc file
4596  * system with zero in s_overhead_clusters the estimate will be close to
4597  * correct especially for very large cluster sizes --- but for newer
4598  * file systems, it's better to calculate this figure once at mkfs
4599  * time, and store it in the superblock.  If the superblock value is
4600  * present (even for non-bigalloc file systems), we will use it.
4601  */
4602 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4603 {
4604 	struct super_block *sb = dentry->d_sb;
4605 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4606 	struct ext4_super_block *es = sbi->s_es;
4607 	struct ext4_group_desc *gdp;
4608 	u64 fsid;
4609 	s64 bfree;
4610 
4611 	if (test_opt(sb, MINIX_DF)) {
4612 		sbi->s_overhead_last = 0;
4613 	} else if (es->s_overhead_clusters) {
4614 		sbi->s_overhead_last = le32_to_cpu(es->s_overhead_clusters);
4615 	} else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
4616 		ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4617 		ext4_fsblk_t overhead = 0;
4618 
4619 		/*
4620 		 * Compute the overhead (FS structures).  This is constant
4621 		 * for a given filesystem unless the number of block groups
4622 		 * changes so we cache the previous value until it does.
4623 		 */
4624 
4625 		/*
4626 		 * All of the blocks before first_data_block are
4627 		 * overhead
4628 		 */
4629 		overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4630 
4631 		/*
4632 		 * Add the overhead found in each block group
4633 		 */
4634 		for (i = 0; i < ngroups; i++) {
4635 			gdp = ext4_get_group_desc(sb, i, NULL);
4636 			overhead += ext4_num_overhead_clusters(sb, i, gdp);
4637 			cond_resched();
4638 		}
4639 		sbi->s_overhead_last = overhead;
4640 		smp_wmb();
4641 		sbi->s_blocks_last = ext4_blocks_count(es);
4642 	}
4643 
4644 	buf->f_type = EXT4_SUPER_MAGIC;
4645 	buf->f_bsize = sb->s_blocksize;
4646 	buf->f_blocks = (ext4_blocks_count(es) -
4647 			 EXT4_C2B(sbi, sbi->s_overhead_last));
4648 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4649 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4650 	/* prevent underflow in case that few free space is available */
4651 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4652 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4653 	if (buf->f_bfree < ext4_r_blocks_count(es))
4654 		buf->f_bavail = 0;
4655 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4656 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4657 	buf->f_namelen = EXT4_NAME_LEN;
4658 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4659 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4660 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4661 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4662 
4663 	return 0;
4664 }
4665 
4666 /* Helper function for writing quotas on sync - we need to start transaction
4667  * before quota file is locked for write. Otherwise the are possible deadlocks:
4668  * Process 1                         Process 2
4669  * ext4_create()                     quota_sync()
4670  *   jbd2_journal_start()                  write_dquot()
4671  *   dquot_initialize()                         down(dqio_mutex)
4672  *     down(dqio_mutex)                    jbd2_journal_start()
4673  *
4674  */
4675 
4676 #ifdef CONFIG_QUOTA
4677 
4678 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4679 {
4680 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4681 }
4682 
4683 static int ext4_write_dquot(struct dquot *dquot)
4684 {
4685 	int ret, err;
4686 	handle_t *handle;
4687 	struct inode *inode;
4688 
4689 	inode = dquot_to_inode(dquot);
4690 	handle = ext4_journal_start(inode,
4691 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4692 	if (IS_ERR(handle))
4693 		return PTR_ERR(handle);
4694 	ret = dquot_commit(dquot);
4695 	err = ext4_journal_stop(handle);
4696 	if (!ret)
4697 		ret = err;
4698 	return ret;
4699 }
4700 
4701 static int ext4_acquire_dquot(struct dquot *dquot)
4702 {
4703 	int ret, err;
4704 	handle_t *handle;
4705 
4706 	handle = ext4_journal_start(dquot_to_inode(dquot),
4707 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4708 	if (IS_ERR(handle))
4709 		return PTR_ERR(handle);
4710 	ret = dquot_acquire(dquot);
4711 	err = ext4_journal_stop(handle);
4712 	if (!ret)
4713 		ret = err;
4714 	return ret;
4715 }
4716 
4717 static int ext4_release_dquot(struct dquot *dquot)
4718 {
4719 	int ret, err;
4720 	handle_t *handle;
4721 
4722 	handle = ext4_journal_start(dquot_to_inode(dquot),
4723 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4724 	if (IS_ERR(handle)) {
4725 		/* Release dquot anyway to avoid endless cycle in dqput() */
4726 		dquot_release(dquot);
4727 		return PTR_ERR(handle);
4728 	}
4729 	ret = dquot_release(dquot);
4730 	err = ext4_journal_stop(handle);
4731 	if (!ret)
4732 		ret = err;
4733 	return ret;
4734 }
4735 
4736 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4737 {
4738 	/* Are we journaling quotas? */
4739 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4740 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4741 		dquot_mark_dquot_dirty(dquot);
4742 		return ext4_write_dquot(dquot);
4743 	} else {
4744 		return dquot_mark_dquot_dirty(dquot);
4745 	}
4746 }
4747 
4748 static int ext4_write_info(struct super_block *sb, int type)
4749 {
4750 	int ret, err;
4751 	handle_t *handle;
4752 
4753 	/* Data block + inode block */
4754 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
4755 	if (IS_ERR(handle))
4756 		return PTR_ERR(handle);
4757 	ret = dquot_commit_info(sb, type);
4758 	err = ext4_journal_stop(handle);
4759 	if (!ret)
4760 		ret = err;
4761 	return ret;
4762 }
4763 
4764 /*
4765  * Turn on quotas during mount time - we need to find
4766  * the quota file and such...
4767  */
4768 static int ext4_quota_on_mount(struct super_block *sb, int type)
4769 {
4770 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4771 					EXT4_SB(sb)->s_jquota_fmt, type);
4772 }
4773 
4774 /*
4775  * Standard function to be called on quota_on
4776  */
4777 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4778 			 struct path *path)
4779 {
4780 	int err;
4781 
4782 	if (!test_opt(sb, QUOTA))
4783 		return -EINVAL;
4784 
4785 	/* Quotafile not on the same filesystem? */
4786 	if (path->mnt->mnt_sb != sb)
4787 		return -EXDEV;
4788 	/* Journaling quota? */
4789 	if (EXT4_SB(sb)->s_qf_names[type]) {
4790 		/* Quotafile not in fs root? */
4791 		if (path->dentry->d_parent != sb->s_root)
4792 			ext4_msg(sb, KERN_WARNING,
4793 				"Quota file not on filesystem root. "
4794 				"Journaled quota will not work");
4795 	}
4796 
4797 	/*
4798 	 * When we journal data on quota file, we have to flush journal to see
4799 	 * all updates to the file when we bypass pagecache...
4800 	 */
4801 	if (EXT4_SB(sb)->s_journal &&
4802 	    ext4_should_journal_data(path->dentry->d_inode)) {
4803 		/*
4804 		 * We don't need to lock updates but journal_flush() could
4805 		 * otherwise be livelocked...
4806 		 */
4807 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4808 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4809 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4810 		if (err)
4811 			return err;
4812 	}
4813 
4814 	return dquot_quota_on(sb, type, format_id, path);
4815 }
4816 
4817 static int ext4_quota_off(struct super_block *sb, int type)
4818 {
4819 	struct inode *inode = sb_dqopt(sb)->files[type];
4820 	handle_t *handle;
4821 
4822 	/* Force all delayed allocation blocks to be allocated.
4823 	 * Caller already holds s_umount sem */
4824 	if (test_opt(sb, DELALLOC))
4825 		sync_filesystem(sb);
4826 
4827 	if (!inode)
4828 		goto out;
4829 
4830 	/* Update modification times of quota files when userspace can
4831 	 * start looking at them */
4832 	handle = ext4_journal_start(inode, 1);
4833 	if (IS_ERR(handle))
4834 		goto out;
4835 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
4836 	ext4_mark_inode_dirty(handle, inode);
4837 	ext4_journal_stop(handle);
4838 
4839 out:
4840 	return dquot_quota_off(sb, type);
4841 }
4842 
4843 /* Read data from quotafile - avoid pagecache and such because we cannot afford
4844  * acquiring the locks... As quota files are never truncated and quota code
4845  * itself serializes the operations (and no one else should touch the files)
4846  * we don't have to be afraid of races */
4847 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
4848 			       size_t len, loff_t off)
4849 {
4850 	struct inode *inode = sb_dqopt(sb)->files[type];
4851 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4852 	int err = 0;
4853 	int offset = off & (sb->s_blocksize - 1);
4854 	int tocopy;
4855 	size_t toread;
4856 	struct buffer_head *bh;
4857 	loff_t i_size = i_size_read(inode);
4858 
4859 	if (off > i_size)
4860 		return 0;
4861 	if (off+len > i_size)
4862 		len = i_size-off;
4863 	toread = len;
4864 	while (toread > 0) {
4865 		tocopy = sb->s_blocksize - offset < toread ?
4866 				sb->s_blocksize - offset : toread;
4867 		bh = ext4_bread(NULL, inode, blk, 0, &err);
4868 		if (err)
4869 			return err;
4870 		if (!bh)	/* A hole? */
4871 			memset(data, 0, tocopy);
4872 		else
4873 			memcpy(data, bh->b_data+offset, tocopy);
4874 		brelse(bh);
4875 		offset = 0;
4876 		toread -= tocopy;
4877 		data += tocopy;
4878 		blk++;
4879 	}
4880 	return len;
4881 }
4882 
4883 /* Write to quotafile (we know the transaction is already started and has
4884  * enough credits) */
4885 static ssize_t ext4_quota_write(struct super_block *sb, int type,
4886 				const char *data, size_t len, loff_t off)
4887 {
4888 	struct inode *inode = sb_dqopt(sb)->files[type];
4889 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4890 	int err = 0;
4891 	int offset = off & (sb->s_blocksize - 1);
4892 	struct buffer_head *bh;
4893 	handle_t *handle = journal_current_handle();
4894 
4895 	if (EXT4_SB(sb)->s_journal && !handle) {
4896 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4897 			" cancelled because transaction is not started",
4898 			(unsigned long long)off, (unsigned long long)len);
4899 		return -EIO;
4900 	}
4901 	/*
4902 	 * Since we account only one data block in transaction credits,
4903 	 * then it is impossible to cross a block boundary.
4904 	 */
4905 	if (sb->s_blocksize - offset < len) {
4906 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4907 			" cancelled because not block aligned",
4908 			(unsigned long long)off, (unsigned long long)len);
4909 		return -EIO;
4910 	}
4911 
4912 	mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
4913 	bh = ext4_bread(handle, inode, blk, 1, &err);
4914 	if (!bh)
4915 		goto out;
4916 	err = ext4_journal_get_write_access(handle, bh);
4917 	if (err) {
4918 		brelse(bh);
4919 		goto out;
4920 	}
4921 	lock_buffer(bh);
4922 	memcpy(bh->b_data+offset, data, len);
4923 	flush_dcache_page(bh->b_page);
4924 	unlock_buffer(bh);
4925 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
4926 	brelse(bh);
4927 out:
4928 	if (err) {
4929 		mutex_unlock(&inode->i_mutex);
4930 		return err;
4931 	}
4932 	if (inode->i_size < off + len) {
4933 		i_size_write(inode, off + len);
4934 		EXT4_I(inode)->i_disksize = inode->i_size;
4935 		ext4_mark_inode_dirty(handle, inode);
4936 	}
4937 	mutex_unlock(&inode->i_mutex);
4938 	return len;
4939 }
4940 
4941 #endif
4942 
4943 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
4944 		       const char *dev_name, void *data)
4945 {
4946 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
4947 }
4948 
4949 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4950 static inline void register_as_ext2(void)
4951 {
4952 	int err = register_filesystem(&ext2_fs_type);
4953 	if (err)
4954 		printk(KERN_WARNING
4955 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
4956 }
4957 
4958 static inline void unregister_as_ext2(void)
4959 {
4960 	unregister_filesystem(&ext2_fs_type);
4961 }
4962 
4963 static inline int ext2_feature_set_ok(struct super_block *sb)
4964 {
4965 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
4966 		return 0;
4967 	if (sb->s_flags & MS_RDONLY)
4968 		return 1;
4969 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
4970 		return 0;
4971 	return 1;
4972 }
4973 MODULE_ALIAS("ext2");
4974 #else
4975 static inline void register_as_ext2(void) { }
4976 static inline void unregister_as_ext2(void) { }
4977 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
4978 #endif
4979 
4980 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4981 static inline void register_as_ext3(void)
4982 {
4983 	int err = register_filesystem(&ext3_fs_type);
4984 	if (err)
4985 		printk(KERN_WARNING
4986 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
4987 }
4988 
4989 static inline void unregister_as_ext3(void)
4990 {
4991 	unregister_filesystem(&ext3_fs_type);
4992 }
4993 
4994 static inline int ext3_feature_set_ok(struct super_block *sb)
4995 {
4996 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
4997 		return 0;
4998 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
4999 		return 0;
5000 	if (sb->s_flags & MS_RDONLY)
5001 		return 1;
5002 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5003 		return 0;
5004 	return 1;
5005 }
5006 MODULE_ALIAS("ext3");
5007 #else
5008 static inline void register_as_ext3(void) { }
5009 static inline void unregister_as_ext3(void) { }
5010 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5011 #endif
5012 
5013 static struct file_system_type ext4_fs_type = {
5014 	.owner		= THIS_MODULE,
5015 	.name		= "ext4",
5016 	.mount		= ext4_mount,
5017 	.kill_sb	= kill_block_super,
5018 	.fs_flags	= FS_REQUIRES_DEV,
5019 };
5020 
5021 static int __init ext4_init_feat_adverts(void)
5022 {
5023 	struct ext4_features *ef;
5024 	int ret = -ENOMEM;
5025 
5026 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5027 	if (!ef)
5028 		goto out;
5029 
5030 	ef->f_kobj.kset = ext4_kset;
5031 	init_completion(&ef->f_kobj_unregister);
5032 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5033 				   "features");
5034 	if (ret) {
5035 		kfree(ef);
5036 		goto out;
5037 	}
5038 
5039 	ext4_feat = ef;
5040 	ret = 0;
5041 out:
5042 	return ret;
5043 }
5044 
5045 static void ext4_exit_feat_adverts(void)
5046 {
5047 	kobject_put(&ext4_feat->f_kobj);
5048 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5049 	kfree(ext4_feat);
5050 }
5051 
5052 /* Shared across all ext4 file systems */
5053 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5054 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5055 
5056 static int __init ext4_init_fs(void)
5057 {
5058 	int i, err;
5059 
5060 	ext4_check_flag_values();
5061 
5062 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5063 		mutex_init(&ext4__aio_mutex[i]);
5064 		init_waitqueue_head(&ext4__ioend_wq[i]);
5065 	}
5066 
5067 	err = ext4_init_pageio();
5068 	if (err)
5069 		return err;
5070 	err = ext4_init_system_zone();
5071 	if (err)
5072 		goto out6;
5073 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5074 	if (!ext4_kset)
5075 		goto out5;
5076 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5077 
5078 	err = ext4_init_feat_adverts();
5079 	if (err)
5080 		goto out4;
5081 
5082 	err = ext4_init_mballoc();
5083 	if (err)
5084 		goto out3;
5085 
5086 	err = ext4_init_xattr();
5087 	if (err)
5088 		goto out2;
5089 	err = init_inodecache();
5090 	if (err)
5091 		goto out1;
5092 	register_as_ext3();
5093 	register_as_ext2();
5094 	err = register_filesystem(&ext4_fs_type);
5095 	if (err)
5096 		goto out;
5097 
5098 	ext4_li_info = NULL;
5099 	mutex_init(&ext4_li_mtx);
5100 	return 0;
5101 out:
5102 	unregister_as_ext2();
5103 	unregister_as_ext3();
5104 	destroy_inodecache();
5105 out1:
5106 	ext4_exit_xattr();
5107 out2:
5108 	ext4_exit_mballoc();
5109 out3:
5110 	ext4_exit_feat_adverts();
5111 out4:
5112 	if (ext4_proc_root)
5113 		remove_proc_entry("fs/ext4", NULL);
5114 	kset_unregister(ext4_kset);
5115 out5:
5116 	ext4_exit_system_zone();
5117 out6:
5118 	ext4_exit_pageio();
5119 	return err;
5120 }
5121 
5122 static void __exit ext4_exit_fs(void)
5123 {
5124 	ext4_destroy_lazyinit_thread();
5125 	unregister_as_ext2();
5126 	unregister_as_ext3();
5127 	unregister_filesystem(&ext4_fs_type);
5128 	destroy_inodecache();
5129 	ext4_exit_xattr();
5130 	ext4_exit_mballoc();
5131 	ext4_exit_feat_adverts();
5132 	remove_proc_entry("fs/ext4", NULL);
5133 	kset_unregister(ext4_kset);
5134 	ext4_exit_system_zone();
5135 	ext4_exit_pageio();
5136 }
5137 
5138 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5139 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5140 MODULE_LICENSE("GPL");
5141 module_init(ext4_init_fs)
5142 module_exit(ext4_exit_fs)
5143