xref: /openbmc/linux/fs/ext4/super.c (revision 5d331b7f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/cleancache.h>
43 #include <linux/uaccess.h>
44 #include <linux/iversion.h>
45 
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 
49 #include "ext4.h"
50 #include "ext4_extents.h"	/* Needed for trace points definition */
51 #include "ext4_jbd2.h"
52 #include "xattr.h"
53 #include "acl.h"
54 #include "mballoc.h"
55 #include "fsmap.h"
56 
57 #define CREATE_TRACE_POINTS
58 #include <trace/events/ext4.h>
59 
60 static struct ext4_lazy_init *ext4_li_info;
61 static struct mutex ext4_li_mtx;
62 static struct ratelimit_state ext4_mount_msg_ratelimit;
63 
64 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
65 			     unsigned long journal_devnum);
66 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
67 static int ext4_commit_super(struct super_block *sb, int sync);
68 static void ext4_mark_recovery_complete(struct super_block *sb,
69 					struct ext4_super_block *es);
70 static void ext4_clear_journal_err(struct super_block *sb,
71 				   struct ext4_super_block *es);
72 static int ext4_sync_fs(struct super_block *sb, int wait);
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 int ext4_freeze(struct super_block *sb);
77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
78 		       const char *dev_name, void *data);
79 static inline int ext2_feature_set_ok(struct super_block *sb);
80 static inline int ext3_feature_set_ok(struct super_block *sb);
81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 
88 /*
89  * Lock ordering
90  *
91  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
92  * i_mmap_rwsem (inode->i_mmap_rwsem)!
93  *
94  * page fault path:
95  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
96  *   page lock -> i_data_sem (rw)
97  *
98  * buffered write path:
99  * sb_start_write -> i_mutex -> mmap_sem
100  * sb_start_write -> i_mutex -> transaction start -> page lock ->
101  *   i_data_sem (rw)
102  *
103  * truncate:
104  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
105  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
106  *   i_data_sem (rw)
107  *
108  * direct IO:
109  * sb_start_write -> i_mutex -> mmap_sem
110  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
111  *
112  * writepages:
113  * transaction start -> page lock(s) -> i_data_sem (rw)
114  */
115 
116 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
117 static struct file_system_type ext2_fs_type = {
118 	.owner		= THIS_MODULE,
119 	.name		= "ext2",
120 	.mount		= ext4_mount,
121 	.kill_sb	= kill_block_super,
122 	.fs_flags	= FS_REQUIRES_DEV,
123 };
124 MODULE_ALIAS_FS("ext2");
125 MODULE_ALIAS("ext2");
126 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
127 #else
128 #define IS_EXT2_SB(sb) (0)
129 #endif
130 
131 
132 static struct file_system_type ext3_fs_type = {
133 	.owner		= THIS_MODULE,
134 	.name		= "ext3",
135 	.mount		= ext4_mount,
136 	.kill_sb	= kill_block_super,
137 	.fs_flags	= FS_REQUIRES_DEV,
138 };
139 MODULE_ALIAS_FS("ext3");
140 MODULE_ALIAS("ext3");
141 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
142 
143 static int ext4_verify_csum_type(struct super_block *sb,
144 				 struct ext4_super_block *es)
145 {
146 	if (!ext4_has_feature_metadata_csum(sb))
147 		return 1;
148 
149 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
150 }
151 
152 static __le32 ext4_superblock_csum(struct super_block *sb,
153 				   struct ext4_super_block *es)
154 {
155 	struct ext4_sb_info *sbi = EXT4_SB(sb);
156 	int offset = offsetof(struct ext4_super_block, s_checksum);
157 	__u32 csum;
158 
159 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
160 
161 	return cpu_to_le32(csum);
162 }
163 
164 static int ext4_superblock_csum_verify(struct super_block *sb,
165 				       struct ext4_super_block *es)
166 {
167 	if (!ext4_has_metadata_csum(sb))
168 		return 1;
169 
170 	return es->s_checksum == ext4_superblock_csum(sb, es);
171 }
172 
173 void ext4_superblock_csum_set(struct super_block *sb)
174 {
175 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
176 
177 	if (!ext4_has_metadata_csum(sb))
178 		return;
179 
180 	es->s_checksum = ext4_superblock_csum(sb, es);
181 }
182 
183 void *ext4_kvmalloc(size_t size, gfp_t flags)
184 {
185 	void *ret;
186 
187 	ret = kmalloc(size, flags | __GFP_NOWARN);
188 	if (!ret)
189 		ret = __vmalloc(size, flags, PAGE_KERNEL);
190 	return ret;
191 }
192 
193 void *ext4_kvzalloc(size_t size, gfp_t flags)
194 {
195 	void *ret;
196 
197 	ret = kzalloc(size, flags | __GFP_NOWARN);
198 	if (!ret)
199 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
200 	return ret;
201 }
202 
203 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
204 			       struct ext4_group_desc *bg)
205 {
206 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
207 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
208 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
209 }
210 
211 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
212 			       struct ext4_group_desc *bg)
213 {
214 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
215 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
216 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
217 }
218 
219 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
220 			      struct ext4_group_desc *bg)
221 {
222 	return le32_to_cpu(bg->bg_inode_table_lo) |
223 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
224 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
225 }
226 
227 __u32 ext4_free_group_clusters(struct super_block *sb,
228 			       struct ext4_group_desc *bg)
229 {
230 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
231 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
232 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
233 }
234 
235 __u32 ext4_free_inodes_count(struct super_block *sb,
236 			      struct ext4_group_desc *bg)
237 {
238 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
239 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
240 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
241 }
242 
243 __u32 ext4_used_dirs_count(struct super_block *sb,
244 			      struct ext4_group_desc *bg)
245 {
246 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
247 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
248 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
249 }
250 
251 __u32 ext4_itable_unused_count(struct super_block *sb,
252 			      struct ext4_group_desc *bg)
253 {
254 	return le16_to_cpu(bg->bg_itable_unused_lo) |
255 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
256 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
257 }
258 
259 void ext4_block_bitmap_set(struct super_block *sb,
260 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
261 {
262 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
263 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
264 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
265 }
266 
267 void ext4_inode_bitmap_set(struct super_block *sb,
268 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
269 {
270 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
271 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
272 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
273 }
274 
275 void ext4_inode_table_set(struct super_block *sb,
276 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
277 {
278 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
279 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
280 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
281 }
282 
283 void ext4_free_group_clusters_set(struct super_block *sb,
284 				  struct ext4_group_desc *bg, __u32 count)
285 {
286 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
287 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
288 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
289 }
290 
291 void ext4_free_inodes_set(struct super_block *sb,
292 			  struct ext4_group_desc *bg, __u32 count)
293 {
294 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
295 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
296 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
297 }
298 
299 void ext4_used_dirs_set(struct super_block *sb,
300 			  struct ext4_group_desc *bg, __u32 count)
301 {
302 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
303 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
304 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
305 }
306 
307 void ext4_itable_unused_set(struct super_block *sb,
308 			  struct ext4_group_desc *bg, __u32 count)
309 {
310 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
311 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
312 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
313 }
314 
315 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
316 {
317 	time64_t now = ktime_get_real_seconds();
318 
319 	now = clamp_val(now, 0, (1ull << 40) - 1);
320 
321 	*lo = cpu_to_le32(lower_32_bits(now));
322 	*hi = upper_32_bits(now);
323 }
324 
325 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
326 {
327 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
328 }
329 #define ext4_update_tstamp(es, tstamp) \
330 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
331 #define ext4_get_tstamp(es, tstamp) \
332 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
333 
334 static void __save_error_info(struct super_block *sb, const char *func,
335 			    unsigned int line)
336 {
337 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
338 
339 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
340 	if (bdev_read_only(sb->s_bdev))
341 		return;
342 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
343 	ext4_update_tstamp(es, s_last_error_time);
344 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
345 	es->s_last_error_line = cpu_to_le32(line);
346 	if (!es->s_first_error_time) {
347 		es->s_first_error_time = es->s_last_error_time;
348 		es->s_first_error_time_hi = es->s_last_error_time_hi;
349 		strncpy(es->s_first_error_func, func,
350 			sizeof(es->s_first_error_func));
351 		es->s_first_error_line = cpu_to_le32(line);
352 		es->s_first_error_ino = es->s_last_error_ino;
353 		es->s_first_error_block = es->s_last_error_block;
354 	}
355 	/*
356 	 * Start the daily error reporting function if it hasn't been
357 	 * started already
358 	 */
359 	if (!es->s_error_count)
360 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
361 	le32_add_cpu(&es->s_error_count, 1);
362 }
363 
364 static void save_error_info(struct super_block *sb, const char *func,
365 			    unsigned int line)
366 {
367 	__save_error_info(sb, func, line);
368 	ext4_commit_super(sb, 1);
369 }
370 
371 /*
372  * The del_gendisk() function uninitializes the disk-specific data
373  * structures, including the bdi structure, without telling anyone
374  * else.  Once this happens, any attempt to call mark_buffer_dirty()
375  * (for example, by ext4_commit_super), will cause a kernel OOPS.
376  * This is a kludge to prevent these oops until we can put in a proper
377  * hook in del_gendisk() to inform the VFS and file system layers.
378  */
379 static int block_device_ejected(struct super_block *sb)
380 {
381 	struct inode *bd_inode = sb->s_bdev->bd_inode;
382 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
383 
384 	return bdi->dev == NULL;
385 }
386 
387 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
388 {
389 	struct super_block		*sb = journal->j_private;
390 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
391 	int				error = is_journal_aborted(journal);
392 	struct ext4_journal_cb_entry	*jce;
393 
394 	BUG_ON(txn->t_state == T_FINISHED);
395 
396 	ext4_process_freed_data(sb, txn->t_tid);
397 
398 	spin_lock(&sbi->s_md_lock);
399 	while (!list_empty(&txn->t_private_list)) {
400 		jce = list_entry(txn->t_private_list.next,
401 				 struct ext4_journal_cb_entry, jce_list);
402 		list_del_init(&jce->jce_list);
403 		spin_unlock(&sbi->s_md_lock);
404 		jce->jce_func(sb, jce, error);
405 		spin_lock(&sbi->s_md_lock);
406 	}
407 	spin_unlock(&sbi->s_md_lock);
408 }
409 
410 /* Deal with the reporting of failure conditions on a filesystem such as
411  * inconsistencies detected or read IO failures.
412  *
413  * On ext2, we can store the error state of the filesystem in the
414  * superblock.  That is not possible on ext4, because we may have other
415  * write ordering constraints on the superblock which prevent us from
416  * writing it out straight away; and given that the journal is about to
417  * be aborted, we can't rely on the current, or future, transactions to
418  * write out the superblock safely.
419  *
420  * We'll just use the jbd2_journal_abort() error code to record an error in
421  * the journal instead.  On recovery, the journal will complain about
422  * that error until we've noted it down and cleared it.
423  */
424 
425 static void ext4_handle_error(struct super_block *sb)
426 {
427 	if (test_opt(sb, WARN_ON_ERROR))
428 		WARN_ON_ONCE(1);
429 
430 	if (sb_rdonly(sb))
431 		return;
432 
433 	if (!test_opt(sb, ERRORS_CONT)) {
434 		journal_t *journal = EXT4_SB(sb)->s_journal;
435 
436 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
437 		if (journal)
438 			jbd2_journal_abort(journal, -EIO);
439 	}
440 	if (test_opt(sb, ERRORS_RO)) {
441 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
442 		/*
443 		 * Make sure updated value of ->s_mount_flags will be visible
444 		 * before ->s_flags update
445 		 */
446 		smp_wmb();
447 		sb->s_flags |= SB_RDONLY;
448 	}
449 	if (test_opt(sb, ERRORS_PANIC)) {
450 		if (EXT4_SB(sb)->s_journal &&
451 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
452 			return;
453 		panic("EXT4-fs (device %s): panic forced after error\n",
454 			sb->s_id);
455 	}
456 }
457 
458 #define ext4_error_ratelimit(sb)					\
459 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
460 			     "EXT4-fs error")
461 
462 void __ext4_error(struct super_block *sb, const char *function,
463 		  unsigned int line, const char *fmt, ...)
464 {
465 	struct va_format vaf;
466 	va_list args;
467 
468 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
469 		return;
470 
471 	trace_ext4_error(sb, function, line);
472 	if (ext4_error_ratelimit(sb)) {
473 		va_start(args, fmt);
474 		vaf.fmt = fmt;
475 		vaf.va = &args;
476 		printk(KERN_CRIT
477 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
478 		       sb->s_id, function, line, current->comm, &vaf);
479 		va_end(args);
480 	}
481 	save_error_info(sb, function, line);
482 	ext4_handle_error(sb);
483 }
484 
485 void __ext4_error_inode(struct inode *inode, const char *function,
486 			unsigned int line, ext4_fsblk_t block,
487 			const char *fmt, ...)
488 {
489 	va_list args;
490 	struct va_format vaf;
491 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
492 
493 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
494 		return;
495 
496 	trace_ext4_error(inode->i_sb, function, line);
497 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
498 	es->s_last_error_block = cpu_to_le64(block);
499 	if (ext4_error_ratelimit(inode->i_sb)) {
500 		va_start(args, fmt);
501 		vaf.fmt = fmt;
502 		vaf.va = &args;
503 		if (block)
504 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
505 			       "inode #%lu: block %llu: comm %s: %pV\n",
506 			       inode->i_sb->s_id, function, line, inode->i_ino,
507 			       block, current->comm, &vaf);
508 		else
509 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
510 			       "inode #%lu: comm %s: %pV\n",
511 			       inode->i_sb->s_id, function, line, inode->i_ino,
512 			       current->comm, &vaf);
513 		va_end(args);
514 	}
515 	save_error_info(inode->i_sb, function, line);
516 	ext4_handle_error(inode->i_sb);
517 }
518 
519 void __ext4_error_file(struct file *file, const char *function,
520 		       unsigned int line, ext4_fsblk_t block,
521 		       const char *fmt, ...)
522 {
523 	va_list args;
524 	struct va_format vaf;
525 	struct ext4_super_block *es;
526 	struct inode *inode = file_inode(file);
527 	char pathname[80], *path;
528 
529 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
530 		return;
531 
532 	trace_ext4_error(inode->i_sb, function, line);
533 	es = EXT4_SB(inode->i_sb)->s_es;
534 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
535 	if (ext4_error_ratelimit(inode->i_sb)) {
536 		path = file_path(file, pathname, sizeof(pathname));
537 		if (IS_ERR(path))
538 			path = "(unknown)";
539 		va_start(args, fmt);
540 		vaf.fmt = fmt;
541 		vaf.va = &args;
542 		if (block)
543 			printk(KERN_CRIT
544 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
545 			       "block %llu: comm %s: path %s: %pV\n",
546 			       inode->i_sb->s_id, function, line, inode->i_ino,
547 			       block, current->comm, path, &vaf);
548 		else
549 			printk(KERN_CRIT
550 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
551 			       "comm %s: path %s: %pV\n",
552 			       inode->i_sb->s_id, function, line, inode->i_ino,
553 			       current->comm, path, &vaf);
554 		va_end(args);
555 	}
556 	save_error_info(inode->i_sb, function, line);
557 	ext4_handle_error(inode->i_sb);
558 }
559 
560 const char *ext4_decode_error(struct super_block *sb, int errno,
561 			      char nbuf[16])
562 {
563 	char *errstr = NULL;
564 
565 	switch (errno) {
566 	case -EFSCORRUPTED:
567 		errstr = "Corrupt filesystem";
568 		break;
569 	case -EFSBADCRC:
570 		errstr = "Filesystem failed CRC";
571 		break;
572 	case -EIO:
573 		errstr = "IO failure";
574 		break;
575 	case -ENOMEM:
576 		errstr = "Out of memory";
577 		break;
578 	case -EROFS:
579 		if (!sb || (EXT4_SB(sb)->s_journal &&
580 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
581 			errstr = "Journal has aborted";
582 		else
583 			errstr = "Readonly filesystem";
584 		break;
585 	default:
586 		/* If the caller passed in an extra buffer for unknown
587 		 * errors, textualise them now.  Else we just return
588 		 * NULL. */
589 		if (nbuf) {
590 			/* Check for truncated error codes... */
591 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
592 				errstr = nbuf;
593 		}
594 		break;
595 	}
596 
597 	return errstr;
598 }
599 
600 /* __ext4_std_error decodes expected errors from journaling functions
601  * automatically and invokes the appropriate error response.  */
602 
603 void __ext4_std_error(struct super_block *sb, const char *function,
604 		      unsigned int line, int errno)
605 {
606 	char nbuf[16];
607 	const char *errstr;
608 
609 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
610 		return;
611 
612 	/* Special case: if the error is EROFS, and we're not already
613 	 * inside a transaction, then there's really no point in logging
614 	 * an error. */
615 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
616 		return;
617 
618 	if (ext4_error_ratelimit(sb)) {
619 		errstr = ext4_decode_error(sb, errno, nbuf);
620 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
621 		       sb->s_id, function, line, errstr);
622 	}
623 
624 	save_error_info(sb, function, line);
625 	ext4_handle_error(sb);
626 }
627 
628 /*
629  * ext4_abort is a much stronger failure handler than ext4_error.  The
630  * abort function may be used to deal with unrecoverable failures such
631  * as journal IO errors or ENOMEM at a critical moment in log management.
632  *
633  * We unconditionally force the filesystem into an ABORT|READONLY state,
634  * unless the error response on the fs has been set to panic in which
635  * case we take the easy way out and panic immediately.
636  */
637 
638 void __ext4_abort(struct super_block *sb, const char *function,
639 		unsigned int line, const char *fmt, ...)
640 {
641 	struct va_format vaf;
642 	va_list args;
643 
644 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
645 		return;
646 
647 	save_error_info(sb, function, line);
648 	va_start(args, fmt);
649 	vaf.fmt = fmt;
650 	vaf.va = &args;
651 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
652 	       sb->s_id, function, line, &vaf);
653 	va_end(args);
654 
655 	if (sb_rdonly(sb) == 0) {
656 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
657 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
658 		/*
659 		 * Make sure updated value of ->s_mount_flags will be visible
660 		 * before ->s_flags update
661 		 */
662 		smp_wmb();
663 		sb->s_flags |= SB_RDONLY;
664 		if (EXT4_SB(sb)->s_journal)
665 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
666 		save_error_info(sb, function, line);
667 	}
668 	if (test_opt(sb, ERRORS_PANIC)) {
669 		if (EXT4_SB(sb)->s_journal &&
670 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
671 			return;
672 		panic("EXT4-fs panic from previous error\n");
673 	}
674 }
675 
676 void __ext4_msg(struct super_block *sb,
677 		const char *prefix, const char *fmt, ...)
678 {
679 	struct va_format vaf;
680 	va_list args;
681 
682 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
683 		return;
684 
685 	va_start(args, fmt);
686 	vaf.fmt = fmt;
687 	vaf.va = &args;
688 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
689 	va_end(args);
690 }
691 
692 #define ext4_warning_ratelimit(sb)					\
693 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
694 			     "EXT4-fs warning")
695 
696 void __ext4_warning(struct super_block *sb, const char *function,
697 		    unsigned int line, const char *fmt, ...)
698 {
699 	struct va_format vaf;
700 	va_list args;
701 
702 	if (!ext4_warning_ratelimit(sb))
703 		return;
704 
705 	va_start(args, fmt);
706 	vaf.fmt = fmt;
707 	vaf.va = &args;
708 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
709 	       sb->s_id, function, line, &vaf);
710 	va_end(args);
711 }
712 
713 void __ext4_warning_inode(const struct inode *inode, const char *function,
714 			  unsigned int line, const char *fmt, ...)
715 {
716 	struct va_format vaf;
717 	va_list args;
718 
719 	if (!ext4_warning_ratelimit(inode->i_sb))
720 		return;
721 
722 	va_start(args, fmt);
723 	vaf.fmt = fmt;
724 	vaf.va = &args;
725 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
726 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
727 	       function, line, inode->i_ino, current->comm, &vaf);
728 	va_end(args);
729 }
730 
731 void __ext4_grp_locked_error(const char *function, unsigned int line,
732 			     struct super_block *sb, ext4_group_t grp,
733 			     unsigned long ino, ext4_fsblk_t block,
734 			     const char *fmt, ...)
735 __releases(bitlock)
736 __acquires(bitlock)
737 {
738 	struct va_format vaf;
739 	va_list args;
740 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
741 
742 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
743 		return;
744 
745 	trace_ext4_error(sb, function, line);
746 	es->s_last_error_ino = cpu_to_le32(ino);
747 	es->s_last_error_block = cpu_to_le64(block);
748 	__save_error_info(sb, function, line);
749 
750 	if (ext4_error_ratelimit(sb)) {
751 		va_start(args, fmt);
752 		vaf.fmt = fmt;
753 		vaf.va = &args;
754 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
755 		       sb->s_id, function, line, grp);
756 		if (ino)
757 			printk(KERN_CONT "inode %lu: ", ino);
758 		if (block)
759 			printk(KERN_CONT "block %llu:",
760 			       (unsigned long long) block);
761 		printk(KERN_CONT "%pV\n", &vaf);
762 		va_end(args);
763 	}
764 
765 	if (test_opt(sb, WARN_ON_ERROR))
766 		WARN_ON_ONCE(1);
767 
768 	if (test_opt(sb, ERRORS_CONT)) {
769 		ext4_commit_super(sb, 0);
770 		return;
771 	}
772 
773 	ext4_unlock_group(sb, grp);
774 	ext4_commit_super(sb, 1);
775 	ext4_handle_error(sb);
776 	/*
777 	 * We only get here in the ERRORS_RO case; relocking the group
778 	 * may be dangerous, but nothing bad will happen since the
779 	 * filesystem will have already been marked read/only and the
780 	 * journal has been aborted.  We return 1 as a hint to callers
781 	 * who might what to use the return value from
782 	 * ext4_grp_locked_error() to distinguish between the
783 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
784 	 * aggressively from the ext4 function in question, with a
785 	 * more appropriate error code.
786 	 */
787 	ext4_lock_group(sb, grp);
788 	return;
789 }
790 
791 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
792 				     ext4_group_t group,
793 				     unsigned int flags)
794 {
795 	struct ext4_sb_info *sbi = EXT4_SB(sb);
796 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
797 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
798 	int ret;
799 
800 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
801 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
802 					    &grp->bb_state);
803 		if (!ret)
804 			percpu_counter_sub(&sbi->s_freeclusters_counter,
805 					   grp->bb_free);
806 	}
807 
808 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
809 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
810 					    &grp->bb_state);
811 		if (!ret && gdp) {
812 			int count;
813 
814 			count = ext4_free_inodes_count(sb, gdp);
815 			percpu_counter_sub(&sbi->s_freeinodes_counter,
816 					   count);
817 		}
818 	}
819 }
820 
821 void ext4_update_dynamic_rev(struct super_block *sb)
822 {
823 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
824 
825 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
826 		return;
827 
828 	ext4_warning(sb,
829 		     "updating to rev %d because of new feature flag, "
830 		     "running e2fsck is recommended",
831 		     EXT4_DYNAMIC_REV);
832 
833 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
834 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
835 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
836 	/* leave es->s_feature_*compat flags alone */
837 	/* es->s_uuid will be set by e2fsck if empty */
838 
839 	/*
840 	 * The rest of the superblock fields should be zero, and if not it
841 	 * means they are likely already in use, so leave them alone.  We
842 	 * can leave it up to e2fsck to clean up any inconsistencies there.
843 	 */
844 }
845 
846 /*
847  * Open the external journal device
848  */
849 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
850 {
851 	struct block_device *bdev;
852 	char b[BDEVNAME_SIZE];
853 
854 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
855 	if (IS_ERR(bdev))
856 		goto fail;
857 	return bdev;
858 
859 fail:
860 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
861 			__bdevname(dev, b), PTR_ERR(bdev));
862 	return NULL;
863 }
864 
865 /*
866  * Release the journal device
867  */
868 static void ext4_blkdev_put(struct block_device *bdev)
869 {
870 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
871 }
872 
873 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
874 {
875 	struct block_device *bdev;
876 	bdev = sbi->journal_bdev;
877 	if (bdev) {
878 		ext4_blkdev_put(bdev);
879 		sbi->journal_bdev = NULL;
880 	}
881 }
882 
883 static inline struct inode *orphan_list_entry(struct list_head *l)
884 {
885 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
886 }
887 
888 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
889 {
890 	struct list_head *l;
891 
892 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
893 		 le32_to_cpu(sbi->s_es->s_last_orphan));
894 
895 	printk(KERN_ERR "sb_info orphan list:\n");
896 	list_for_each(l, &sbi->s_orphan) {
897 		struct inode *inode = orphan_list_entry(l);
898 		printk(KERN_ERR "  "
899 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
900 		       inode->i_sb->s_id, inode->i_ino, inode,
901 		       inode->i_mode, inode->i_nlink,
902 		       NEXT_ORPHAN(inode));
903 	}
904 }
905 
906 #ifdef CONFIG_QUOTA
907 static int ext4_quota_off(struct super_block *sb, int type);
908 
909 static inline void ext4_quota_off_umount(struct super_block *sb)
910 {
911 	int type;
912 
913 	/* Use our quota_off function to clear inode flags etc. */
914 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
915 		ext4_quota_off(sb, type);
916 }
917 
918 /*
919  * This is a helper function which is used in the mount/remount
920  * codepaths (which holds s_umount) to fetch the quota file name.
921  */
922 static inline char *get_qf_name(struct super_block *sb,
923 				struct ext4_sb_info *sbi,
924 				int type)
925 {
926 	return rcu_dereference_protected(sbi->s_qf_names[type],
927 					 lockdep_is_held(&sb->s_umount));
928 }
929 #else
930 static inline void ext4_quota_off_umount(struct super_block *sb)
931 {
932 }
933 #endif
934 
935 static void ext4_put_super(struct super_block *sb)
936 {
937 	struct ext4_sb_info *sbi = EXT4_SB(sb);
938 	struct ext4_super_block *es = sbi->s_es;
939 	int aborted = 0;
940 	int i, err;
941 
942 	ext4_unregister_li_request(sb);
943 	ext4_quota_off_umount(sb);
944 
945 	destroy_workqueue(sbi->rsv_conversion_wq);
946 
947 	if (sbi->s_journal) {
948 		aborted = is_journal_aborted(sbi->s_journal);
949 		err = jbd2_journal_destroy(sbi->s_journal);
950 		sbi->s_journal = NULL;
951 		if ((err < 0) && !aborted)
952 			ext4_abort(sb, "Couldn't clean up the journal");
953 	}
954 
955 	ext4_unregister_sysfs(sb);
956 	ext4_es_unregister_shrinker(sbi);
957 	del_timer_sync(&sbi->s_err_report);
958 	ext4_release_system_zone(sb);
959 	ext4_mb_release(sb);
960 	ext4_ext_release(sb);
961 
962 	if (!sb_rdonly(sb) && !aborted) {
963 		ext4_clear_feature_journal_needs_recovery(sb);
964 		es->s_state = cpu_to_le16(sbi->s_mount_state);
965 	}
966 	if (!sb_rdonly(sb))
967 		ext4_commit_super(sb, 1);
968 
969 	for (i = 0; i < sbi->s_gdb_count; i++)
970 		brelse(sbi->s_group_desc[i]);
971 	kvfree(sbi->s_group_desc);
972 	kvfree(sbi->s_flex_groups);
973 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
974 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
975 	percpu_counter_destroy(&sbi->s_dirs_counter);
976 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
977 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
978 #ifdef CONFIG_QUOTA
979 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
980 		kfree(get_qf_name(sb, sbi, i));
981 #endif
982 
983 	/* Debugging code just in case the in-memory inode orphan list
984 	 * isn't empty.  The on-disk one can be non-empty if we've
985 	 * detected an error and taken the fs readonly, but the
986 	 * in-memory list had better be clean by this point. */
987 	if (!list_empty(&sbi->s_orphan))
988 		dump_orphan_list(sb, sbi);
989 	J_ASSERT(list_empty(&sbi->s_orphan));
990 
991 	sync_blockdev(sb->s_bdev);
992 	invalidate_bdev(sb->s_bdev);
993 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
994 		/*
995 		 * Invalidate the journal device's buffers.  We don't want them
996 		 * floating about in memory - the physical journal device may
997 		 * hotswapped, and it breaks the `ro-after' testing code.
998 		 */
999 		sync_blockdev(sbi->journal_bdev);
1000 		invalidate_bdev(sbi->journal_bdev);
1001 		ext4_blkdev_remove(sbi);
1002 	}
1003 	if (sbi->s_ea_inode_cache) {
1004 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1005 		sbi->s_ea_inode_cache = NULL;
1006 	}
1007 	if (sbi->s_ea_block_cache) {
1008 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1009 		sbi->s_ea_block_cache = NULL;
1010 	}
1011 	if (sbi->s_mmp_tsk)
1012 		kthread_stop(sbi->s_mmp_tsk);
1013 	brelse(sbi->s_sbh);
1014 	sb->s_fs_info = NULL;
1015 	/*
1016 	 * Now that we are completely done shutting down the
1017 	 * superblock, we need to actually destroy the kobject.
1018 	 */
1019 	kobject_put(&sbi->s_kobj);
1020 	wait_for_completion(&sbi->s_kobj_unregister);
1021 	if (sbi->s_chksum_driver)
1022 		crypto_free_shash(sbi->s_chksum_driver);
1023 	kfree(sbi->s_blockgroup_lock);
1024 	fs_put_dax(sbi->s_daxdev);
1025 	kfree(sbi);
1026 }
1027 
1028 static struct kmem_cache *ext4_inode_cachep;
1029 
1030 /*
1031  * Called inside transaction, so use GFP_NOFS
1032  */
1033 static struct inode *ext4_alloc_inode(struct super_block *sb)
1034 {
1035 	struct ext4_inode_info *ei;
1036 
1037 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1038 	if (!ei)
1039 		return NULL;
1040 
1041 	inode_set_iversion(&ei->vfs_inode, 1);
1042 	spin_lock_init(&ei->i_raw_lock);
1043 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1044 	spin_lock_init(&ei->i_prealloc_lock);
1045 	ext4_es_init_tree(&ei->i_es_tree);
1046 	rwlock_init(&ei->i_es_lock);
1047 	INIT_LIST_HEAD(&ei->i_es_list);
1048 	ei->i_es_all_nr = 0;
1049 	ei->i_es_shk_nr = 0;
1050 	ei->i_es_shrink_lblk = 0;
1051 	ei->i_reserved_data_blocks = 0;
1052 	ei->i_da_metadata_calc_len = 0;
1053 	ei->i_da_metadata_calc_last_lblock = 0;
1054 	spin_lock_init(&(ei->i_block_reservation_lock));
1055 	ext4_init_pending_tree(&ei->i_pending_tree);
1056 #ifdef CONFIG_QUOTA
1057 	ei->i_reserved_quota = 0;
1058 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1059 #endif
1060 	ei->jinode = NULL;
1061 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1062 	spin_lock_init(&ei->i_completed_io_lock);
1063 	ei->i_sync_tid = 0;
1064 	ei->i_datasync_tid = 0;
1065 	atomic_set(&ei->i_unwritten, 0);
1066 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1067 	return &ei->vfs_inode;
1068 }
1069 
1070 static int ext4_drop_inode(struct inode *inode)
1071 {
1072 	int drop = generic_drop_inode(inode);
1073 
1074 	trace_ext4_drop_inode(inode, drop);
1075 	return drop;
1076 }
1077 
1078 static void ext4_i_callback(struct rcu_head *head)
1079 {
1080 	struct inode *inode = container_of(head, struct inode, i_rcu);
1081 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1082 }
1083 
1084 static void ext4_destroy_inode(struct inode *inode)
1085 {
1086 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1087 		ext4_msg(inode->i_sb, KERN_ERR,
1088 			 "Inode %lu (%p): orphan list check failed!",
1089 			 inode->i_ino, EXT4_I(inode));
1090 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1091 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1092 				true);
1093 		dump_stack();
1094 	}
1095 	call_rcu(&inode->i_rcu, ext4_i_callback);
1096 }
1097 
1098 static void init_once(void *foo)
1099 {
1100 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1101 
1102 	INIT_LIST_HEAD(&ei->i_orphan);
1103 	init_rwsem(&ei->xattr_sem);
1104 	init_rwsem(&ei->i_data_sem);
1105 	init_rwsem(&ei->i_mmap_sem);
1106 	inode_init_once(&ei->vfs_inode);
1107 }
1108 
1109 static int __init init_inodecache(void)
1110 {
1111 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1112 				sizeof(struct ext4_inode_info), 0,
1113 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1114 					SLAB_ACCOUNT),
1115 				offsetof(struct ext4_inode_info, i_data),
1116 				sizeof_field(struct ext4_inode_info, i_data),
1117 				init_once);
1118 	if (ext4_inode_cachep == NULL)
1119 		return -ENOMEM;
1120 	return 0;
1121 }
1122 
1123 static void destroy_inodecache(void)
1124 {
1125 	/*
1126 	 * Make sure all delayed rcu free inodes are flushed before we
1127 	 * destroy cache.
1128 	 */
1129 	rcu_barrier();
1130 	kmem_cache_destroy(ext4_inode_cachep);
1131 }
1132 
1133 void ext4_clear_inode(struct inode *inode)
1134 {
1135 	invalidate_inode_buffers(inode);
1136 	clear_inode(inode);
1137 	dquot_drop(inode);
1138 	ext4_discard_preallocations(inode);
1139 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1140 	if (EXT4_I(inode)->jinode) {
1141 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1142 					       EXT4_I(inode)->jinode);
1143 		jbd2_free_inode(EXT4_I(inode)->jinode);
1144 		EXT4_I(inode)->jinode = NULL;
1145 	}
1146 	fscrypt_put_encryption_info(inode);
1147 }
1148 
1149 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1150 					u64 ino, u32 generation)
1151 {
1152 	struct inode *inode;
1153 
1154 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1155 		return ERR_PTR(-ESTALE);
1156 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1157 		return ERR_PTR(-ESTALE);
1158 
1159 	/* iget isn't really right if the inode is currently unallocated!!
1160 	 *
1161 	 * ext4_read_inode will return a bad_inode if the inode had been
1162 	 * deleted, so we should be safe.
1163 	 *
1164 	 * Currently we don't know the generation for parent directory, so
1165 	 * a generation of 0 means "accept any"
1166 	 */
1167 	inode = ext4_iget_normal(sb, ino);
1168 	if (IS_ERR(inode))
1169 		return ERR_CAST(inode);
1170 	if (generation && inode->i_generation != generation) {
1171 		iput(inode);
1172 		return ERR_PTR(-ESTALE);
1173 	}
1174 
1175 	return inode;
1176 }
1177 
1178 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1179 					int fh_len, int fh_type)
1180 {
1181 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1182 				    ext4_nfs_get_inode);
1183 }
1184 
1185 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1186 					int fh_len, int fh_type)
1187 {
1188 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1189 				    ext4_nfs_get_inode);
1190 }
1191 
1192 /*
1193  * Try to release metadata pages (indirect blocks, directories) which are
1194  * mapped via the block device.  Since these pages could have journal heads
1195  * which would prevent try_to_free_buffers() from freeing them, we must use
1196  * jbd2 layer's try_to_free_buffers() function to release them.
1197  */
1198 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1199 				 gfp_t wait)
1200 {
1201 	journal_t *journal = EXT4_SB(sb)->s_journal;
1202 
1203 	WARN_ON(PageChecked(page));
1204 	if (!page_has_buffers(page))
1205 		return 0;
1206 	if (journal)
1207 		return jbd2_journal_try_to_free_buffers(journal, page,
1208 						wait & ~__GFP_DIRECT_RECLAIM);
1209 	return try_to_free_buffers(page);
1210 }
1211 
1212 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1213 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1214 {
1215 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1216 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1217 }
1218 
1219 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1220 							void *fs_data)
1221 {
1222 	handle_t *handle = fs_data;
1223 	int res, res2, credits, retries = 0;
1224 
1225 	/*
1226 	 * Encrypting the root directory is not allowed because e2fsck expects
1227 	 * lost+found to exist and be unencrypted, and encrypting the root
1228 	 * directory would imply encrypting the lost+found directory as well as
1229 	 * the filename "lost+found" itself.
1230 	 */
1231 	if (inode->i_ino == EXT4_ROOT_INO)
1232 		return -EPERM;
1233 
1234 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1235 		return -EINVAL;
1236 
1237 	res = ext4_convert_inline_data(inode);
1238 	if (res)
1239 		return res;
1240 
1241 	/*
1242 	 * If a journal handle was specified, then the encryption context is
1243 	 * being set on a new inode via inheritance and is part of a larger
1244 	 * transaction to create the inode.  Otherwise the encryption context is
1245 	 * being set on an existing inode in its own transaction.  Only in the
1246 	 * latter case should the "retry on ENOSPC" logic be used.
1247 	 */
1248 
1249 	if (handle) {
1250 		res = ext4_xattr_set_handle(handle, inode,
1251 					    EXT4_XATTR_INDEX_ENCRYPTION,
1252 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1253 					    ctx, len, 0);
1254 		if (!res) {
1255 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1256 			ext4_clear_inode_state(inode,
1257 					EXT4_STATE_MAY_INLINE_DATA);
1258 			/*
1259 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1260 			 * S_DAX may be disabled
1261 			 */
1262 			ext4_set_inode_flags(inode);
1263 		}
1264 		return res;
1265 	}
1266 
1267 	res = dquot_initialize(inode);
1268 	if (res)
1269 		return res;
1270 retry:
1271 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1272 				     &credits);
1273 	if (res)
1274 		return res;
1275 
1276 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1277 	if (IS_ERR(handle))
1278 		return PTR_ERR(handle);
1279 
1280 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1281 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1282 				    ctx, len, 0);
1283 	if (!res) {
1284 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1285 		/*
1286 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1287 		 * S_DAX may be disabled
1288 		 */
1289 		ext4_set_inode_flags(inode);
1290 		res = ext4_mark_inode_dirty(handle, inode);
1291 		if (res)
1292 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1293 	}
1294 	res2 = ext4_journal_stop(handle);
1295 
1296 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1297 		goto retry;
1298 	if (!res)
1299 		res = res2;
1300 	return res;
1301 }
1302 
1303 static bool ext4_dummy_context(struct inode *inode)
1304 {
1305 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1306 }
1307 
1308 static const struct fscrypt_operations ext4_cryptops = {
1309 	.key_prefix		= "ext4:",
1310 	.get_context		= ext4_get_context,
1311 	.set_context		= ext4_set_context,
1312 	.dummy_context		= ext4_dummy_context,
1313 	.empty_dir		= ext4_empty_dir,
1314 	.max_namelen		= EXT4_NAME_LEN,
1315 };
1316 #endif
1317 
1318 #ifdef CONFIG_QUOTA
1319 static const char * const quotatypes[] = INITQFNAMES;
1320 #define QTYPE2NAME(t) (quotatypes[t])
1321 
1322 static int ext4_write_dquot(struct dquot *dquot);
1323 static int ext4_acquire_dquot(struct dquot *dquot);
1324 static int ext4_release_dquot(struct dquot *dquot);
1325 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1326 static int ext4_write_info(struct super_block *sb, int type);
1327 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1328 			 const struct path *path);
1329 static int ext4_quota_on_mount(struct super_block *sb, int type);
1330 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1331 			       size_t len, loff_t off);
1332 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1333 				const char *data, size_t len, loff_t off);
1334 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1335 			     unsigned int flags);
1336 static int ext4_enable_quotas(struct super_block *sb);
1337 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1338 
1339 static struct dquot **ext4_get_dquots(struct inode *inode)
1340 {
1341 	return EXT4_I(inode)->i_dquot;
1342 }
1343 
1344 static const struct dquot_operations ext4_quota_operations = {
1345 	.get_reserved_space	= ext4_get_reserved_space,
1346 	.write_dquot		= ext4_write_dquot,
1347 	.acquire_dquot		= ext4_acquire_dquot,
1348 	.release_dquot		= ext4_release_dquot,
1349 	.mark_dirty		= ext4_mark_dquot_dirty,
1350 	.write_info		= ext4_write_info,
1351 	.alloc_dquot		= dquot_alloc,
1352 	.destroy_dquot		= dquot_destroy,
1353 	.get_projid		= ext4_get_projid,
1354 	.get_inode_usage	= ext4_get_inode_usage,
1355 	.get_next_id		= ext4_get_next_id,
1356 };
1357 
1358 static const struct quotactl_ops ext4_qctl_operations = {
1359 	.quota_on	= ext4_quota_on,
1360 	.quota_off	= ext4_quota_off,
1361 	.quota_sync	= dquot_quota_sync,
1362 	.get_state	= dquot_get_state,
1363 	.set_info	= dquot_set_dqinfo,
1364 	.get_dqblk	= dquot_get_dqblk,
1365 	.set_dqblk	= dquot_set_dqblk,
1366 	.get_nextdqblk	= dquot_get_next_dqblk,
1367 };
1368 #endif
1369 
1370 static const struct super_operations ext4_sops = {
1371 	.alloc_inode	= ext4_alloc_inode,
1372 	.destroy_inode	= ext4_destroy_inode,
1373 	.write_inode	= ext4_write_inode,
1374 	.dirty_inode	= ext4_dirty_inode,
1375 	.drop_inode	= ext4_drop_inode,
1376 	.evict_inode	= ext4_evict_inode,
1377 	.put_super	= ext4_put_super,
1378 	.sync_fs	= ext4_sync_fs,
1379 	.freeze_fs	= ext4_freeze,
1380 	.unfreeze_fs	= ext4_unfreeze,
1381 	.statfs		= ext4_statfs,
1382 	.remount_fs	= ext4_remount,
1383 	.show_options	= ext4_show_options,
1384 #ifdef CONFIG_QUOTA
1385 	.quota_read	= ext4_quota_read,
1386 	.quota_write	= ext4_quota_write,
1387 	.get_dquots	= ext4_get_dquots,
1388 #endif
1389 	.bdev_try_to_free_page = bdev_try_to_free_page,
1390 };
1391 
1392 static const struct export_operations ext4_export_ops = {
1393 	.fh_to_dentry = ext4_fh_to_dentry,
1394 	.fh_to_parent = ext4_fh_to_parent,
1395 	.get_parent = ext4_get_parent,
1396 };
1397 
1398 enum {
1399 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1400 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1401 	Opt_nouid32, Opt_debug, Opt_removed,
1402 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1403 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1404 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1405 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1406 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1407 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1408 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1409 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1410 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1411 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1412 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1413 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1414 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1415 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1416 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1417 	Opt_dioread_nolock, Opt_dioread_lock,
1418 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1419 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1420 };
1421 
1422 static const match_table_t tokens = {
1423 	{Opt_bsd_df, "bsddf"},
1424 	{Opt_minix_df, "minixdf"},
1425 	{Opt_grpid, "grpid"},
1426 	{Opt_grpid, "bsdgroups"},
1427 	{Opt_nogrpid, "nogrpid"},
1428 	{Opt_nogrpid, "sysvgroups"},
1429 	{Opt_resgid, "resgid=%u"},
1430 	{Opt_resuid, "resuid=%u"},
1431 	{Opt_sb, "sb=%u"},
1432 	{Opt_err_cont, "errors=continue"},
1433 	{Opt_err_panic, "errors=panic"},
1434 	{Opt_err_ro, "errors=remount-ro"},
1435 	{Opt_nouid32, "nouid32"},
1436 	{Opt_debug, "debug"},
1437 	{Opt_removed, "oldalloc"},
1438 	{Opt_removed, "orlov"},
1439 	{Opt_user_xattr, "user_xattr"},
1440 	{Opt_nouser_xattr, "nouser_xattr"},
1441 	{Opt_acl, "acl"},
1442 	{Opt_noacl, "noacl"},
1443 	{Opt_noload, "norecovery"},
1444 	{Opt_noload, "noload"},
1445 	{Opt_removed, "nobh"},
1446 	{Opt_removed, "bh"},
1447 	{Opt_commit, "commit=%u"},
1448 	{Opt_min_batch_time, "min_batch_time=%u"},
1449 	{Opt_max_batch_time, "max_batch_time=%u"},
1450 	{Opt_journal_dev, "journal_dev=%u"},
1451 	{Opt_journal_path, "journal_path=%s"},
1452 	{Opt_journal_checksum, "journal_checksum"},
1453 	{Opt_nojournal_checksum, "nojournal_checksum"},
1454 	{Opt_journal_async_commit, "journal_async_commit"},
1455 	{Opt_abort, "abort"},
1456 	{Opt_data_journal, "data=journal"},
1457 	{Opt_data_ordered, "data=ordered"},
1458 	{Opt_data_writeback, "data=writeback"},
1459 	{Opt_data_err_abort, "data_err=abort"},
1460 	{Opt_data_err_ignore, "data_err=ignore"},
1461 	{Opt_offusrjquota, "usrjquota="},
1462 	{Opt_usrjquota, "usrjquota=%s"},
1463 	{Opt_offgrpjquota, "grpjquota="},
1464 	{Opt_grpjquota, "grpjquota=%s"},
1465 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1466 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1467 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1468 	{Opt_grpquota, "grpquota"},
1469 	{Opt_noquota, "noquota"},
1470 	{Opt_quota, "quota"},
1471 	{Opt_usrquota, "usrquota"},
1472 	{Opt_prjquota, "prjquota"},
1473 	{Opt_barrier, "barrier=%u"},
1474 	{Opt_barrier, "barrier"},
1475 	{Opt_nobarrier, "nobarrier"},
1476 	{Opt_i_version, "i_version"},
1477 	{Opt_dax, "dax"},
1478 	{Opt_stripe, "stripe=%u"},
1479 	{Opt_delalloc, "delalloc"},
1480 	{Opt_warn_on_error, "warn_on_error"},
1481 	{Opt_nowarn_on_error, "nowarn_on_error"},
1482 	{Opt_lazytime, "lazytime"},
1483 	{Opt_nolazytime, "nolazytime"},
1484 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1485 	{Opt_nodelalloc, "nodelalloc"},
1486 	{Opt_removed, "mblk_io_submit"},
1487 	{Opt_removed, "nomblk_io_submit"},
1488 	{Opt_block_validity, "block_validity"},
1489 	{Opt_noblock_validity, "noblock_validity"},
1490 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1491 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1492 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1493 	{Opt_auto_da_alloc, "auto_da_alloc"},
1494 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1495 	{Opt_dioread_nolock, "dioread_nolock"},
1496 	{Opt_dioread_lock, "dioread_lock"},
1497 	{Opt_discard, "discard"},
1498 	{Opt_nodiscard, "nodiscard"},
1499 	{Opt_init_itable, "init_itable=%u"},
1500 	{Opt_init_itable, "init_itable"},
1501 	{Opt_noinit_itable, "noinit_itable"},
1502 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1503 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1504 	{Opt_nombcache, "nombcache"},
1505 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1506 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1507 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1508 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1509 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1510 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1511 	{Opt_err, NULL},
1512 };
1513 
1514 static ext4_fsblk_t get_sb_block(void **data)
1515 {
1516 	ext4_fsblk_t	sb_block;
1517 	char		*options = (char *) *data;
1518 
1519 	if (!options || strncmp(options, "sb=", 3) != 0)
1520 		return 1;	/* Default location */
1521 
1522 	options += 3;
1523 	/* TODO: use simple_strtoll with >32bit ext4 */
1524 	sb_block = simple_strtoul(options, &options, 0);
1525 	if (*options && *options != ',') {
1526 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1527 		       (char *) *data);
1528 		return 1;
1529 	}
1530 	if (*options == ',')
1531 		options++;
1532 	*data = (void *) options;
1533 
1534 	return sb_block;
1535 }
1536 
1537 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1538 static const char deprecated_msg[] =
1539 	"Mount option \"%s\" will be removed by %s\n"
1540 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1541 
1542 #ifdef CONFIG_QUOTA
1543 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1544 {
1545 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1546 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1547 	int ret = -1;
1548 
1549 	if (sb_any_quota_loaded(sb) && !old_qname) {
1550 		ext4_msg(sb, KERN_ERR,
1551 			"Cannot change journaled "
1552 			"quota options when quota turned on");
1553 		return -1;
1554 	}
1555 	if (ext4_has_feature_quota(sb)) {
1556 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1557 			 "ignored when QUOTA feature is enabled");
1558 		return 1;
1559 	}
1560 	qname = match_strdup(args);
1561 	if (!qname) {
1562 		ext4_msg(sb, KERN_ERR,
1563 			"Not enough memory for storing quotafile name");
1564 		return -1;
1565 	}
1566 	if (old_qname) {
1567 		if (strcmp(old_qname, qname) == 0)
1568 			ret = 1;
1569 		else
1570 			ext4_msg(sb, KERN_ERR,
1571 				 "%s quota file already specified",
1572 				 QTYPE2NAME(qtype));
1573 		goto errout;
1574 	}
1575 	if (strchr(qname, '/')) {
1576 		ext4_msg(sb, KERN_ERR,
1577 			"quotafile must be on filesystem root");
1578 		goto errout;
1579 	}
1580 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1581 	set_opt(sb, QUOTA);
1582 	return 1;
1583 errout:
1584 	kfree(qname);
1585 	return ret;
1586 }
1587 
1588 static int clear_qf_name(struct super_block *sb, int qtype)
1589 {
1590 
1591 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1592 	char *old_qname = get_qf_name(sb, sbi, qtype);
1593 
1594 	if (sb_any_quota_loaded(sb) && old_qname) {
1595 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1596 			" when quota turned on");
1597 		return -1;
1598 	}
1599 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1600 	synchronize_rcu();
1601 	kfree(old_qname);
1602 	return 1;
1603 }
1604 #endif
1605 
1606 #define MOPT_SET	0x0001
1607 #define MOPT_CLEAR	0x0002
1608 #define MOPT_NOSUPPORT	0x0004
1609 #define MOPT_EXPLICIT	0x0008
1610 #define MOPT_CLEAR_ERR	0x0010
1611 #define MOPT_GTE0	0x0020
1612 #ifdef CONFIG_QUOTA
1613 #define MOPT_Q		0
1614 #define MOPT_QFMT	0x0040
1615 #else
1616 #define MOPT_Q		MOPT_NOSUPPORT
1617 #define MOPT_QFMT	MOPT_NOSUPPORT
1618 #endif
1619 #define MOPT_DATAJ	0x0080
1620 #define MOPT_NO_EXT2	0x0100
1621 #define MOPT_NO_EXT3	0x0200
1622 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1623 #define MOPT_STRING	0x0400
1624 
1625 static const struct mount_opts {
1626 	int	token;
1627 	int	mount_opt;
1628 	int	flags;
1629 } ext4_mount_opts[] = {
1630 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1631 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1632 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1633 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1634 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1635 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1636 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1637 	 MOPT_EXT4_ONLY | MOPT_SET},
1638 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1639 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1640 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1641 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1642 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1643 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1644 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1645 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1646 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1647 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1648 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1649 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1650 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1651 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1652 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1653 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1654 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1655 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1656 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1657 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1658 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1659 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1660 	 MOPT_NO_EXT2},
1661 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1662 	 MOPT_NO_EXT2},
1663 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1664 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1665 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1666 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1667 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1668 	{Opt_commit, 0, MOPT_GTE0},
1669 	{Opt_max_batch_time, 0, MOPT_GTE0},
1670 	{Opt_min_batch_time, 0, MOPT_GTE0},
1671 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1672 	{Opt_init_itable, 0, MOPT_GTE0},
1673 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1674 	{Opt_stripe, 0, MOPT_GTE0},
1675 	{Opt_resuid, 0, MOPT_GTE0},
1676 	{Opt_resgid, 0, MOPT_GTE0},
1677 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1678 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1679 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1680 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1681 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1682 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1683 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1684 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1685 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1686 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1687 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1688 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1689 #else
1690 	{Opt_acl, 0, MOPT_NOSUPPORT},
1691 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1692 #endif
1693 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1694 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1695 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1696 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1697 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1698 							MOPT_SET | MOPT_Q},
1699 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1700 							MOPT_SET | MOPT_Q},
1701 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1702 							MOPT_SET | MOPT_Q},
1703 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1704 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1705 							MOPT_CLEAR | MOPT_Q},
1706 	{Opt_usrjquota, 0, MOPT_Q},
1707 	{Opt_grpjquota, 0, MOPT_Q},
1708 	{Opt_offusrjquota, 0, MOPT_Q},
1709 	{Opt_offgrpjquota, 0, MOPT_Q},
1710 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1711 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1712 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1713 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1714 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1715 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1716 	{Opt_err, 0, 0}
1717 };
1718 
1719 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1720 			    substring_t *args, unsigned long *journal_devnum,
1721 			    unsigned int *journal_ioprio, int is_remount)
1722 {
1723 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1724 	const struct mount_opts *m;
1725 	kuid_t uid;
1726 	kgid_t gid;
1727 	int arg = 0;
1728 
1729 #ifdef CONFIG_QUOTA
1730 	if (token == Opt_usrjquota)
1731 		return set_qf_name(sb, USRQUOTA, &args[0]);
1732 	else if (token == Opt_grpjquota)
1733 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1734 	else if (token == Opt_offusrjquota)
1735 		return clear_qf_name(sb, USRQUOTA);
1736 	else if (token == Opt_offgrpjquota)
1737 		return clear_qf_name(sb, GRPQUOTA);
1738 #endif
1739 	switch (token) {
1740 	case Opt_noacl:
1741 	case Opt_nouser_xattr:
1742 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1743 		break;
1744 	case Opt_sb:
1745 		return 1;	/* handled by get_sb_block() */
1746 	case Opt_removed:
1747 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1748 		return 1;
1749 	case Opt_abort:
1750 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1751 		return 1;
1752 	case Opt_i_version:
1753 		sb->s_flags |= SB_I_VERSION;
1754 		return 1;
1755 	case Opt_lazytime:
1756 		sb->s_flags |= SB_LAZYTIME;
1757 		return 1;
1758 	case Opt_nolazytime:
1759 		sb->s_flags &= ~SB_LAZYTIME;
1760 		return 1;
1761 	}
1762 
1763 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1764 		if (token == m->token)
1765 			break;
1766 
1767 	if (m->token == Opt_err) {
1768 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1769 			 "or missing value", opt);
1770 		return -1;
1771 	}
1772 
1773 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1774 		ext4_msg(sb, KERN_ERR,
1775 			 "Mount option \"%s\" incompatible with ext2", opt);
1776 		return -1;
1777 	}
1778 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1779 		ext4_msg(sb, KERN_ERR,
1780 			 "Mount option \"%s\" incompatible with ext3", opt);
1781 		return -1;
1782 	}
1783 
1784 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1785 		return -1;
1786 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1787 		return -1;
1788 	if (m->flags & MOPT_EXPLICIT) {
1789 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1790 			set_opt2(sb, EXPLICIT_DELALLOC);
1791 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1792 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1793 		} else
1794 			return -1;
1795 	}
1796 	if (m->flags & MOPT_CLEAR_ERR)
1797 		clear_opt(sb, ERRORS_MASK);
1798 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1799 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1800 			 "options when quota turned on");
1801 		return -1;
1802 	}
1803 
1804 	if (m->flags & MOPT_NOSUPPORT) {
1805 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1806 	} else if (token == Opt_commit) {
1807 		if (arg == 0)
1808 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1809 		sbi->s_commit_interval = HZ * arg;
1810 	} else if (token == Opt_debug_want_extra_isize) {
1811 		sbi->s_want_extra_isize = arg;
1812 	} else if (token == Opt_max_batch_time) {
1813 		sbi->s_max_batch_time = arg;
1814 	} else if (token == Opt_min_batch_time) {
1815 		sbi->s_min_batch_time = arg;
1816 	} else if (token == Opt_inode_readahead_blks) {
1817 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1818 			ext4_msg(sb, KERN_ERR,
1819 				 "EXT4-fs: inode_readahead_blks must be "
1820 				 "0 or a power of 2 smaller than 2^31");
1821 			return -1;
1822 		}
1823 		sbi->s_inode_readahead_blks = arg;
1824 	} else if (token == Opt_init_itable) {
1825 		set_opt(sb, INIT_INODE_TABLE);
1826 		if (!args->from)
1827 			arg = EXT4_DEF_LI_WAIT_MULT;
1828 		sbi->s_li_wait_mult = arg;
1829 	} else if (token == Opt_max_dir_size_kb) {
1830 		sbi->s_max_dir_size_kb = arg;
1831 	} else if (token == Opt_stripe) {
1832 		sbi->s_stripe = arg;
1833 	} else if (token == Opt_resuid) {
1834 		uid = make_kuid(current_user_ns(), arg);
1835 		if (!uid_valid(uid)) {
1836 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1837 			return -1;
1838 		}
1839 		sbi->s_resuid = uid;
1840 	} else if (token == Opt_resgid) {
1841 		gid = make_kgid(current_user_ns(), arg);
1842 		if (!gid_valid(gid)) {
1843 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1844 			return -1;
1845 		}
1846 		sbi->s_resgid = gid;
1847 	} else if (token == Opt_journal_dev) {
1848 		if (is_remount) {
1849 			ext4_msg(sb, KERN_ERR,
1850 				 "Cannot specify journal on remount");
1851 			return -1;
1852 		}
1853 		*journal_devnum = arg;
1854 	} else if (token == Opt_journal_path) {
1855 		char *journal_path;
1856 		struct inode *journal_inode;
1857 		struct path path;
1858 		int error;
1859 
1860 		if (is_remount) {
1861 			ext4_msg(sb, KERN_ERR,
1862 				 "Cannot specify journal on remount");
1863 			return -1;
1864 		}
1865 		journal_path = match_strdup(&args[0]);
1866 		if (!journal_path) {
1867 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1868 				"journal device string");
1869 			return -1;
1870 		}
1871 
1872 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1873 		if (error) {
1874 			ext4_msg(sb, KERN_ERR, "error: could not find "
1875 				"journal device path: error %d", error);
1876 			kfree(journal_path);
1877 			return -1;
1878 		}
1879 
1880 		journal_inode = d_inode(path.dentry);
1881 		if (!S_ISBLK(journal_inode->i_mode)) {
1882 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1883 				"is not a block device", journal_path);
1884 			path_put(&path);
1885 			kfree(journal_path);
1886 			return -1;
1887 		}
1888 
1889 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1890 		path_put(&path);
1891 		kfree(journal_path);
1892 	} else if (token == Opt_journal_ioprio) {
1893 		if (arg > 7) {
1894 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1895 				 " (must be 0-7)");
1896 			return -1;
1897 		}
1898 		*journal_ioprio =
1899 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1900 	} else if (token == Opt_test_dummy_encryption) {
1901 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1902 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1903 		ext4_msg(sb, KERN_WARNING,
1904 			 "Test dummy encryption mode enabled");
1905 #else
1906 		ext4_msg(sb, KERN_WARNING,
1907 			 "Test dummy encryption mount option ignored");
1908 #endif
1909 	} else if (m->flags & MOPT_DATAJ) {
1910 		if (is_remount) {
1911 			if (!sbi->s_journal)
1912 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1913 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1914 				ext4_msg(sb, KERN_ERR,
1915 					 "Cannot change data mode on remount");
1916 				return -1;
1917 			}
1918 		} else {
1919 			clear_opt(sb, DATA_FLAGS);
1920 			sbi->s_mount_opt |= m->mount_opt;
1921 		}
1922 #ifdef CONFIG_QUOTA
1923 	} else if (m->flags & MOPT_QFMT) {
1924 		if (sb_any_quota_loaded(sb) &&
1925 		    sbi->s_jquota_fmt != m->mount_opt) {
1926 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1927 				 "quota options when quota turned on");
1928 			return -1;
1929 		}
1930 		if (ext4_has_feature_quota(sb)) {
1931 			ext4_msg(sb, KERN_INFO,
1932 				 "Quota format mount options ignored "
1933 				 "when QUOTA feature is enabled");
1934 			return 1;
1935 		}
1936 		sbi->s_jquota_fmt = m->mount_opt;
1937 #endif
1938 	} else if (token == Opt_dax) {
1939 #ifdef CONFIG_FS_DAX
1940 		ext4_msg(sb, KERN_WARNING,
1941 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1942 			sbi->s_mount_opt |= m->mount_opt;
1943 #else
1944 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1945 		return -1;
1946 #endif
1947 	} else if (token == Opt_data_err_abort) {
1948 		sbi->s_mount_opt |= m->mount_opt;
1949 	} else if (token == Opt_data_err_ignore) {
1950 		sbi->s_mount_opt &= ~m->mount_opt;
1951 	} else {
1952 		if (!args->from)
1953 			arg = 1;
1954 		if (m->flags & MOPT_CLEAR)
1955 			arg = !arg;
1956 		else if (unlikely(!(m->flags & MOPT_SET))) {
1957 			ext4_msg(sb, KERN_WARNING,
1958 				 "buggy handling of option %s", opt);
1959 			WARN_ON(1);
1960 			return -1;
1961 		}
1962 		if (arg != 0)
1963 			sbi->s_mount_opt |= m->mount_opt;
1964 		else
1965 			sbi->s_mount_opt &= ~m->mount_opt;
1966 	}
1967 	return 1;
1968 }
1969 
1970 static int parse_options(char *options, struct super_block *sb,
1971 			 unsigned long *journal_devnum,
1972 			 unsigned int *journal_ioprio,
1973 			 int is_remount)
1974 {
1975 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1976 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
1977 	substring_t args[MAX_OPT_ARGS];
1978 	int token;
1979 
1980 	if (!options)
1981 		return 1;
1982 
1983 	while ((p = strsep(&options, ",")) != NULL) {
1984 		if (!*p)
1985 			continue;
1986 		/*
1987 		 * Initialize args struct so we know whether arg was
1988 		 * found; some options take optional arguments.
1989 		 */
1990 		args[0].to = args[0].from = NULL;
1991 		token = match_token(p, tokens, args);
1992 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1993 				     journal_ioprio, is_remount) < 0)
1994 			return 0;
1995 	}
1996 #ifdef CONFIG_QUOTA
1997 	/*
1998 	 * We do the test below only for project quotas. 'usrquota' and
1999 	 * 'grpquota' mount options are allowed even without quota feature
2000 	 * to support legacy quotas in quota files.
2001 	 */
2002 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2003 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2004 			 "Cannot enable project quota enforcement.");
2005 		return 0;
2006 	}
2007 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2008 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2009 	if (usr_qf_name || grp_qf_name) {
2010 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2011 			clear_opt(sb, USRQUOTA);
2012 
2013 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2014 			clear_opt(sb, GRPQUOTA);
2015 
2016 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2017 			ext4_msg(sb, KERN_ERR, "old and new quota "
2018 					"format mixing");
2019 			return 0;
2020 		}
2021 
2022 		if (!sbi->s_jquota_fmt) {
2023 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2024 					"not specified");
2025 			return 0;
2026 		}
2027 	}
2028 #endif
2029 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2030 		int blocksize =
2031 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2032 
2033 		if (blocksize < PAGE_SIZE) {
2034 			ext4_msg(sb, KERN_ERR, "can't mount with "
2035 				 "dioread_nolock if block size != PAGE_SIZE");
2036 			return 0;
2037 		}
2038 	}
2039 	return 1;
2040 }
2041 
2042 static inline void ext4_show_quota_options(struct seq_file *seq,
2043 					   struct super_block *sb)
2044 {
2045 #if defined(CONFIG_QUOTA)
2046 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2047 	char *usr_qf_name, *grp_qf_name;
2048 
2049 	if (sbi->s_jquota_fmt) {
2050 		char *fmtname = "";
2051 
2052 		switch (sbi->s_jquota_fmt) {
2053 		case QFMT_VFS_OLD:
2054 			fmtname = "vfsold";
2055 			break;
2056 		case QFMT_VFS_V0:
2057 			fmtname = "vfsv0";
2058 			break;
2059 		case QFMT_VFS_V1:
2060 			fmtname = "vfsv1";
2061 			break;
2062 		}
2063 		seq_printf(seq, ",jqfmt=%s", fmtname);
2064 	}
2065 
2066 	rcu_read_lock();
2067 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2068 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2069 	if (usr_qf_name)
2070 		seq_show_option(seq, "usrjquota", usr_qf_name);
2071 	if (grp_qf_name)
2072 		seq_show_option(seq, "grpjquota", grp_qf_name);
2073 	rcu_read_unlock();
2074 #endif
2075 }
2076 
2077 static const char *token2str(int token)
2078 {
2079 	const struct match_token *t;
2080 
2081 	for (t = tokens; t->token != Opt_err; t++)
2082 		if (t->token == token && !strchr(t->pattern, '='))
2083 			break;
2084 	return t->pattern;
2085 }
2086 
2087 /*
2088  * Show an option if
2089  *  - it's set to a non-default value OR
2090  *  - if the per-sb default is different from the global default
2091  */
2092 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2093 			      int nodefs)
2094 {
2095 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2096 	struct ext4_super_block *es = sbi->s_es;
2097 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2098 	const struct mount_opts *m;
2099 	char sep = nodefs ? '\n' : ',';
2100 
2101 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2102 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2103 
2104 	if (sbi->s_sb_block != 1)
2105 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2106 
2107 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2108 		int want_set = m->flags & MOPT_SET;
2109 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2110 		    (m->flags & MOPT_CLEAR_ERR))
2111 			continue;
2112 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2113 			continue; /* skip if same as the default */
2114 		if ((want_set &&
2115 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2116 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2117 			continue; /* select Opt_noFoo vs Opt_Foo */
2118 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2119 	}
2120 
2121 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2122 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2123 		SEQ_OPTS_PRINT("resuid=%u",
2124 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2125 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2126 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2127 		SEQ_OPTS_PRINT("resgid=%u",
2128 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2129 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2130 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2131 		SEQ_OPTS_PUTS("errors=remount-ro");
2132 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2133 		SEQ_OPTS_PUTS("errors=continue");
2134 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2135 		SEQ_OPTS_PUTS("errors=panic");
2136 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2137 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2138 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2139 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2140 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2141 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2142 	if (sb->s_flags & SB_I_VERSION)
2143 		SEQ_OPTS_PUTS("i_version");
2144 	if (nodefs || sbi->s_stripe)
2145 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2146 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2147 			(sbi->s_mount_opt ^ def_mount_opt)) {
2148 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2149 			SEQ_OPTS_PUTS("data=journal");
2150 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2151 			SEQ_OPTS_PUTS("data=ordered");
2152 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2153 			SEQ_OPTS_PUTS("data=writeback");
2154 	}
2155 	if (nodefs ||
2156 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2157 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2158 			       sbi->s_inode_readahead_blks);
2159 
2160 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2161 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2162 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2163 	if (nodefs || sbi->s_max_dir_size_kb)
2164 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2165 	if (test_opt(sb, DATA_ERR_ABORT))
2166 		SEQ_OPTS_PUTS("data_err=abort");
2167 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
2168 		SEQ_OPTS_PUTS("test_dummy_encryption");
2169 
2170 	ext4_show_quota_options(seq, sb);
2171 	return 0;
2172 }
2173 
2174 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2175 {
2176 	return _ext4_show_options(seq, root->d_sb, 0);
2177 }
2178 
2179 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2180 {
2181 	struct super_block *sb = seq->private;
2182 	int rc;
2183 
2184 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2185 	rc = _ext4_show_options(seq, sb, 1);
2186 	seq_puts(seq, "\n");
2187 	return rc;
2188 }
2189 
2190 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2191 			    int read_only)
2192 {
2193 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2194 	int err = 0;
2195 
2196 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2197 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2198 			 "forcing read-only mode");
2199 		err = -EROFS;
2200 	}
2201 	if (read_only)
2202 		goto done;
2203 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2204 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2205 			 "running e2fsck is recommended");
2206 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2207 		ext4_msg(sb, KERN_WARNING,
2208 			 "warning: mounting fs with errors, "
2209 			 "running e2fsck is recommended");
2210 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2211 		 le16_to_cpu(es->s_mnt_count) >=
2212 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2213 		ext4_msg(sb, KERN_WARNING,
2214 			 "warning: maximal mount count reached, "
2215 			 "running e2fsck is recommended");
2216 	else if (le32_to_cpu(es->s_checkinterval) &&
2217 		 (ext4_get_tstamp(es, s_lastcheck) +
2218 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2219 		ext4_msg(sb, KERN_WARNING,
2220 			 "warning: checktime reached, "
2221 			 "running e2fsck is recommended");
2222 	if (!sbi->s_journal)
2223 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2224 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2225 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2226 	le16_add_cpu(&es->s_mnt_count, 1);
2227 	ext4_update_tstamp(es, s_mtime);
2228 	ext4_update_dynamic_rev(sb);
2229 	if (sbi->s_journal)
2230 		ext4_set_feature_journal_needs_recovery(sb);
2231 
2232 	err = ext4_commit_super(sb, 1);
2233 done:
2234 	if (test_opt(sb, DEBUG))
2235 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2236 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2237 			sb->s_blocksize,
2238 			sbi->s_groups_count,
2239 			EXT4_BLOCKS_PER_GROUP(sb),
2240 			EXT4_INODES_PER_GROUP(sb),
2241 			sbi->s_mount_opt, sbi->s_mount_opt2);
2242 
2243 	cleancache_init_fs(sb);
2244 	return err;
2245 }
2246 
2247 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2248 {
2249 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2250 	struct flex_groups *new_groups;
2251 	int size;
2252 
2253 	if (!sbi->s_log_groups_per_flex)
2254 		return 0;
2255 
2256 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2257 	if (size <= sbi->s_flex_groups_allocated)
2258 		return 0;
2259 
2260 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2261 	new_groups = kvzalloc(size, GFP_KERNEL);
2262 	if (!new_groups) {
2263 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2264 			 size / (int) sizeof(struct flex_groups));
2265 		return -ENOMEM;
2266 	}
2267 
2268 	if (sbi->s_flex_groups) {
2269 		memcpy(new_groups, sbi->s_flex_groups,
2270 		       (sbi->s_flex_groups_allocated *
2271 			sizeof(struct flex_groups)));
2272 		kvfree(sbi->s_flex_groups);
2273 	}
2274 	sbi->s_flex_groups = new_groups;
2275 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2276 	return 0;
2277 }
2278 
2279 static int ext4_fill_flex_info(struct super_block *sb)
2280 {
2281 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2282 	struct ext4_group_desc *gdp = NULL;
2283 	ext4_group_t flex_group;
2284 	int i, err;
2285 
2286 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2287 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2288 		sbi->s_log_groups_per_flex = 0;
2289 		return 1;
2290 	}
2291 
2292 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2293 	if (err)
2294 		goto failed;
2295 
2296 	for (i = 0; i < sbi->s_groups_count; i++) {
2297 		gdp = ext4_get_group_desc(sb, i, NULL);
2298 
2299 		flex_group = ext4_flex_group(sbi, i);
2300 		atomic_add(ext4_free_inodes_count(sb, gdp),
2301 			   &sbi->s_flex_groups[flex_group].free_inodes);
2302 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2303 			     &sbi->s_flex_groups[flex_group].free_clusters);
2304 		atomic_add(ext4_used_dirs_count(sb, gdp),
2305 			   &sbi->s_flex_groups[flex_group].used_dirs);
2306 	}
2307 
2308 	return 1;
2309 failed:
2310 	return 0;
2311 }
2312 
2313 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2314 				   struct ext4_group_desc *gdp)
2315 {
2316 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2317 	__u16 crc = 0;
2318 	__le32 le_group = cpu_to_le32(block_group);
2319 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2320 
2321 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2322 		/* Use new metadata_csum algorithm */
2323 		__u32 csum32;
2324 		__u16 dummy_csum = 0;
2325 
2326 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2327 				     sizeof(le_group));
2328 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2329 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2330 				     sizeof(dummy_csum));
2331 		offset += sizeof(dummy_csum);
2332 		if (offset < sbi->s_desc_size)
2333 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2334 					     sbi->s_desc_size - offset);
2335 
2336 		crc = csum32 & 0xFFFF;
2337 		goto out;
2338 	}
2339 
2340 	/* old crc16 code */
2341 	if (!ext4_has_feature_gdt_csum(sb))
2342 		return 0;
2343 
2344 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2345 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2346 	crc = crc16(crc, (__u8 *)gdp, offset);
2347 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2348 	/* for checksum of struct ext4_group_desc do the rest...*/
2349 	if (ext4_has_feature_64bit(sb) &&
2350 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2351 		crc = crc16(crc, (__u8 *)gdp + offset,
2352 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2353 				offset);
2354 
2355 out:
2356 	return cpu_to_le16(crc);
2357 }
2358 
2359 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2360 				struct ext4_group_desc *gdp)
2361 {
2362 	if (ext4_has_group_desc_csum(sb) &&
2363 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2364 		return 0;
2365 
2366 	return 1;
2367 }
2368 
2369 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2370 			      struct ext4_group_desc *gdp)
2371 {
2372 	if (!ext4_has_group_desc_csum(sb))
2373 		return;
2374 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2375 }
2376 
2377 /* Called at mount-time, super-block is locked */
2378 static int ext4_check_descriptors(struct super_block *sb,
2379 				  ext4_fsblk_t sb_block,
2380 				  ext4_group_t *first_not_zeroed)
2381 {
2382 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2383 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2384 	ext4_fsblk_t last_block;
2385 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2386 	ext4_fsblk_t block_bitmap;
2387 	ext4_fsblk_t inode_bitmap;
2388 	ext4_fsblk_t inode_table;
2389 	int flexbg_flag = 0;
2390 	ext4_group_t i, grp = sbi->s_groups_count;
2391 
2392 	if (ext4_has_feature_flex_bg(sb))
2393 		flexbg_flag = 1;
2394 
2395 	ext4_debug("Checking group descriptors");
2396 
2397 	for (i = 0; i < sbi->s_groups_count; i++) {
2398 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2399 
2400 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2401 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2402 		else
2403 			last_block = first_block +
2404 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2405 
2406 		if ((grp == sbi->s_groups_count) &&
2407 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2408 			grp = i;
2409 
2410 		block_bitmap = ext4_block_bitmap(sb, gdp);
2411 		if (block_bitmap == sb_block) {
2412 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2413 				 "Block bitmap for group %u overlaps "
2414 				 "superblock", i);
2415 			if (!sb_rdonly(sb))
2416 				return 0;
2417 		}
2418 		if (block_bitmap >= sb_block + 1 &&
2419 		    block_bitmap <= last_bg_block) {
2420 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2421 				 "Block bitmap for group %u overlaps "
2422 				 "block group descriptors", i);
2423 			if (!sb_rdonly(sb))
2424 				return 0;
2425 		}
2426 		if (block_bitmap < first_block || block_bitmap > last_block) {
2427 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2428 			       "Block bitmap for group %u not in group "
2429 			       "(block %llu)!", i, block_bitmap);
2430 			return 0;
2431 		}
2432 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2433 		if (inode_bitmap == sb_block) {
2434 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2435 				 "Inode bitmap for group %u overlaps "
2436 				 "superblock", i);
2437 			if (!sb_rdonly(sb))
2438 				return 0;
2439 		}
2440 		if (inode_bitmap >= sb_block + 1 &&
2441 		    inode_bitmap <= last_bg_block) {
2442 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2443 				 "Inode bitmap for group %u overlaps "
2444 				 "block group descriptors", i);
2445 			if (!sb_rdonly(sb))
2446 				return 0;
2447 		}
2448 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2449 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2450 			       "Inode bitmap for group %u not in group "
2451 			       "(block %llu)!", i, inode_bitmap);
2452 			return 0;
2453 		}
2454 		inode_table = ext4_inode_table(sb, gdp);
2455 		if (inode_table == sb_block) {
2456 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2457 				 "Inode table for group %u overlaps "
2458 				 "superblock", i);
2459 			if (!sb_rdonly(sb))
2460 				return 0;
2461 		}
2462 		if (inode_table >= sb_block + 1 &&
2463 		    inode_table <= last_bg_block) {
2464 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2465 				 "Inode table for group %u overlaps "
2466 				 "block group descriptors", i);
2467 			if (!sb_rdonly(sb))
2468 				return 0;
2469 		}
2470 		if (inode_table < first_block ||
2471 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2472 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2473 			       "Inode table for group %u not in group "
2474 			       "(block %llu)!", i, inode_table);
2475 			return 0;
2476 		}
2477 		ext4_lock_group(sb, i);
2478 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2479 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2480 				 "Checksum for group %u failed (%u!=%u)",
2481 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2482 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2483 			if (!sb_rdonly(sb)) {
2484 				ext4_unlock_group(sb, i);
2485 				return 0;
2486 			}
2487 		}
2488 		ext4_unlock_group(sb, i);
2489 		if (!flexbg_flag)
2490 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2491 	}
2492 	if (NULL != first_not_zeroed)
2493 		*first_not_zeroed = grp;
2494 	return 1;
2495 }
2496 
2497 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2498  * the superblock) which were deleted from all directories, but held open by
2499  * a process at the time of a crash.  We walk the list and try to delete these
2500  * inodes at recovery time (only with a read-write filesystem).
2501  *
2502  * In order to keep the orphan inode chain consistent during traversal (in
2503  * case of crash during recovery), we link each inode into the superblock
2504  * orphan list_head and handle it the same way as an inode deletion during
2505  * normal operation (which journals the operations for us).
2506  *
2507  * We only do an iget() and an iput() on each inode, which is very safe if we
2508  * accidentally point at an in-use or already deleted inode.  The worst that
2509  * can happen in this case is that we get a "bit already cleared" message from
2510  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2511  * e2fsck was run on this filesystem, and it must have already done the orphan
2512  * inode cleanup for us, so we can safely abort without any further action.
2513  */
2514 static void ext4_orphan_cleanup(struct super_block *sb,
2515 				struct ext4_super_block *es)
2516 {
2517 	unsigned int s_flags = sb->s_flags;
2518 	int ret, nr_orphans = 0, nr_truncates = 0;
2519 #ifdef CONFIG_QUOTA
2520 	int quota_update = 0;
2521 	int i;
2522 #endif
2523 	if (!es->s_last_orphan) {
2524 		jbd_debug(4, "no orphan inodes to clean up\n");
2525 		return;
2526 	}
2527 
2528 	if (bdev_read_only(sb->s_bdev)) {
2529 		ext4_msg(sb, KERN_ERR, "write access "
2530 			"unavailable, skipping orphan cleanup");
2531 		return;
2532 	}
2533 
2534 	/* Check if feature set would not allow a r/w mount */
2535 	if (!ext4_feature_set_ok(sb, 0)) {
2536 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2537 			 "unknown ROCOMPAT features");
2538 		return;
2539 	}
2540 
2541 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2542 		/* don't clear list on RO mount w/ errors */
2543 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2544 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2545 				  "clearing orphan list.\n");
2546 			es->s_last_orphan = 0;
2547 		}
2548 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2549 		return;
2550 	}
2551 
2552 	if (s_flags & SB_RDONLY) {
2553 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2554 		sb->s_flags &= ~SB_RDONLY;
2555 	}
2556 #ifdef CONFIG_QUOTA
2557 	/* Needed for iput() to work correctly and not trash data */
2558 	sb->s_flags |= SB_ACTIVE;
2559 
2560 	/*
2561 	 * Turn on quotas which were not enabled for read-only mounts if
2562 	 * filesystem has quota feature, so that they are updated correctly.
2563 	 */
2564 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2565 		int ret = ext4_enable_quotas(sb);
2566 
2567 		if (!ret)
2568 			quota_update = 1;
2569 		else
2570 			ext4_msg(sb, KERN_ERR,
2571 				"Cannot turn on quotas: error %d", ret);
2572 	}
2573 
2574 	/* Turn on journaled quotas used for old sytle */
2575 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2576 		if (EXT4_SB(sb)->s_qf_names[i]) {
2577 			int ret = ext4_quota_on_mount(sb, i);
2578 
2579 			if (!ret)
2580 				quota_update = 1;
2581 			else
2582 				ext4_msg(sb, KERN_ERR,
2583 					"Cannot turn on journaled "
2584 					"quota: type %d: error %d", i, ret);
2585 		}
2586 	}
2587 #endif
2588 
2589 	while (es->s_last_orphan) {
2590 		struct inode *inode;
2591 
2592 		/*
2593 		 * We may have encountered an error during cleanup; if
2594 		 * so, skip the rest.
2595 		 */
2596 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2597 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2598 			es->s_last_orphan = 0;
2599 			break;
2600 		}
2601 
2602 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2603 		if (IS_ERR(inode)) {
2604 			es->s_last_orphan = 0;
2605 			break;
2606 		}
2607 
2608 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2609 		dquot_initialize(inode);
2610 		if (inode->i_nlink) {
2611 			if (test_opt(sb, DEBUG))
2612 				ext4_msg(sb, KERN_DEBUG,
2613 					"%s: truncating inode %lu to %lld bytes",
2614 					__func__, inode->i_ino, inode->i_size);
2615 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2616 				  inode->i_ino, inode->i_size);
2617 			inode_lock(inode);
2618 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2619 			ret = ext4_truncate(inode);
2620 			if (ret)
2621 				ext4_std_error(inode->i_sb, ret);
2622 			inode_unlock(inode);
2623 			nr_truncates++;
2624 		} else {
2625 			if (test_opt(sb, DEBUG))
2626 				ext4_msg(sb, KERN_DEBUG,
2627 					"%s: deleting unreferenced inode %lu",
2628 					__func__, inode->i_ino);
2629 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2630 				  inode->i_ino);
2631 			nr_orphans++;
2632 		}
2633 		iput(inode);  /* The delete magic happens here! */
2634 	}
2635 
2636 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2637 
2638 	if (nr_orphans)
2639 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2640 		       PLURAL(nr_orphans));
2641 	if (nr_truncates)
2642 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2643 		       PLURAL(nr_truncates));
2644 #ifdef CONFIG_QUOTA
2645 	/* Turn off quotas if they were enabled for orphan cleanup */
2646 	if (quota_update) {
2647 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2648 			if (sb_dqopt(sb)->files[i])
2649 				dquot_quota_off(sb, i);
2650 		}
2651 	}
2652 #endif
2653 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2654 }
2655 
2656 /*
2657  * Maximal extent format file size.
2658  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2659  * extent format containers, within a sector_t, and within i_blocks
2660  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2661  * so that won't be a limiting factor.
2662  *
2663  * However there is other limiting factor. We do store extents in the form
2664  * of starting block and length, hence the resulting length of the extent
2665  * covering maximum file size must fit into on-disk format containers as
2666  * well. Given that length is always by 1 unit bigger than max unit (because
2667  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2668  *
2669  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2670  */
2671 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2672 {
2673 	loff_t res;
2674 	loff_t upper_limit = MAX_LFS_FILESIZE;
2675 
2676 	/* small i_blocks in vfs inode? */
2677 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2678 		/*
2679 		 * CONFIG_LBDAF is not enabled implies the inode
2680 		 * i_block represent total blocks in 512 bytes
2681 		 * 32 == size of vfs inode i_blocks * 8
2682 		 */
2683 		upper_limit = (1LL << 32) - 1;
2684 
2685 		/* total blocks in file system block size */
2686 		upper_limit >>= (blkbits - 9);
2687 		upper_limit <<= blkbits;
2688 	}
2689 
2690 	/*
2691 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2692 	 * by one fs block, so ee_len can cover the extent of maximum file
2693 	 * size
2694 	 */
2695 	res = (1LL << 32) - 1;
2696 	res <<= blkbits;
2697 
2698 	/* Sanity check against vm- & vfs- imposed limits */
2699 	if (res > upper_limit)
2700 		res = upper_limit;
2701 
2702 	return res;
2703 }
2704 
2705 /*
2706  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2707  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2708  * We need to be 1 filesystem block less than the 2^48 sector limit.
2709  */
2710 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2711 {
2712 	loff_t res = EXT4_NDIR_BLOCKS;
2713 	int meta_blocks;
2714 	loff_t upper_limit;
2715 	/* This is calculated to be the largest file size for a dense, block
2716 	 * mapped file such that the file's total number of 512-byte sectors,
2717 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2718 	 *
2719 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2720 	 * number of 512-byte sectors of the file.
2721 	 */
2722 
2723 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2724 		/*
2725 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2726 		 * the inode i_block field represents total file blocks in
2727 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2728 		 */
2729 		upper_limit = (1LL << 32) - 1;
2730 
2731 		/* total blocks in file system block size */
2732 		upper_limit >>= (bits - 9);
2733 
2734 	} else {
2735 		/*
2736 		 * We use 48 bit ext4_inode i_blocks
2737 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2738 		 * represent total number of blocks in
2739 		 * file system block size
2740 		 */
2741 		upper_limit = (1LL << 48) - 1;
2742 
2743 	}
2744 
2745 	/* indirect blocks */
2746 	meta_blocks = 1;
2747 	/* double indirect blocks */
2748 	meta_blocks += 1 + (1LL << (bits-2));
2749 	/* tripple indirect blocks */
2750 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2751 
2752 	upper_limit -= meta_blocks;
2753 	upper_limit <<= bits;
2754 
2755 	res += 1LL << (bits-2);
2756 	res += 1LL << (2*(bits-2));
2757 	res += 1LL << (3*(bits-2));
2758 	res <<= bits;
2759 	if (res > upper_limit)
2760 		res = upper_limit;
2761 
2762 	if (res > MAX_LFS_FILESIZE)
2763 		res = MAX_LFS_FILESIZE;
2764 
2765 	return res;
2766 }
2767 
2768 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2769 				   ext4_fsblk_t logical_sb_block, int nr)
2770 {
2771 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2772 	ext4_group_t bg, first_meta_bg;
2773 	int has_super = 0;
2774 
2775 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2776 
2777 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2778 		return logical_sb_block + nr + 1;
2779 	bg = sbi->s_desc_per_block * nr;
2780 	if (ext4_bg_has_super(sb, bg))
2781 		has_super = 1;
2782 
2783 	/*
2784 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2785 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2786 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2787 	 * compensate.
2788 	 */
2789 	if (sb->s_blocksize == 1024 && nr == 0 &&
2790 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2791 		has_super++;
2792 
2793 	return (has_super + ext4_group_first_block_no(sb, bg));
2794 }
2795 
2796 /**
2797  * ext4_get_stripe_size: Get the stripe size.
2798  * @sbi: In memory super block info
2799  *
2800  * If we have specified it via mount option, then
2801  * use the mount option value. If the value specified at mount time is
2802  * greater than the blocks per group use the super block value.
2803  * If the super block value is greater than blocks per group return 0.
2804  * Allocator needs it be less than blocks per group.
2805  *
2806  */
2807 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2808 {
2809 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2810 	unsigned long stripe_width =
2811 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2812 	int ret;
2813 
2814 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2815 		ret = sbi->s_stripe;
2816 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2817 		ret = stripe_width;
2818 	else if (stride && stride <= sbi->s_blocks_per_group)
2819 		ret = stride;
2820 	else
2821 		ret = 0;
2822 
2823 	/*
2824 	 * If the stripe width is 1, this makes no sense and
2825 	 * we set it to 0 to turn off stripe handling code.
2826 	 */
2827 	if (ret <= 1)
2828 		ret = 0;
2829 
2830 	return ret;
2831 }
2832 
2833 /*
2834  * Check whether this filesystem can be mounted based on
2835  * the features present and the RDONLY/RDWR mount requested.
2836  * Returns 1 if this filesystem can be mounted as requested,
2837  * 0 if it cannot be.
2838  */
2839 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2840 {
2841 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2842 		ext4_msg(sb, KERN_ERR,
2843 			"Couldn't mount because of "
2844 			"unsupported optional features (%x)",
2845 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2846 			~EXT4_FEATURE_INCOMPAT_SUPP));
2847 		return 0;
2848 	}
2849 
2850 	if (readonly)
2851 		return 1;
2852 
2853 	if (ext4_has_feature_readonly(sb)) {
2854 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2855 		sb->s_flags |= SB_RDONLY;
2856 		return 1;
2857 	}
2858 
2859 	/* Check that feature set is OK for a read-write mount */
2860 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2861 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2862 			 "unsupported optional features (%x)",
2863 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2864 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2865 		return 0;
2866 	}
2867 	/*
2868 	 * Large file size enabled file system can only be mounted
2869 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2870 	 */
2871 	if (ext4_has_feature_huge_file(sb)) {
2872 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2873 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2874 				 "cannot be mounted RDWR without "
2875 				 "CONFIG_LBDAF");
2876 			return 0;
2877 		}
2878 	}
2879 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2880 		ext4_msg(sb, KERN_ERR,
2881 			 "Can't support bigalloc feature without "
2882 			 "extents feature\n");
2883 		return 0;
2884 	}
2885 
2886 #ifndef CONFIG_QUOTA
2887 	if (ext4_has_feature_quota(sb) && !readonly) {
2888 		ext4_msg(sb, KERN_ERR,
2889 			 "Filesystem with quota feature cannot be mounted RDWR "
2890 			 "without CONFIG_QUOTA");
2891 		return 0;
2892 	}
2893 	if (ext4_has_feature_project(sb) && !readonly) {
2894 		ext4_msg(sb, KERN_ERR,
2895 			 "Filesystem with project quota feature cannot be mounted RDWR "
2896 			 "without CONFIG_QUOTA");
2897 		return 0;
2898 	}
2899 #endif  /* CONFIG_QUOTA */
2900 	return 1;
2901 }
2902 
2903 /*
2904  * This function is called once a day if we have errors logged
2905  * on the file system
2906  */
2907 static void print_daily_error_info(struct timer_list *t)
2908 {
2909 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2910 	struct super_block *sb = sbi->s_sb;
2911 	struct ext4_super_block *es = sbi->s_es;
2912 
2913 	if (es->s_error_count)
2914 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2915 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2916 			 le32_to_cpu(es->s_error_count));
2917 	if (es->s_first_error_time) {
2918 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
2919 		       sb->s_id,
2920 		       ext4_get_tstamp(es, s_first_error_time),
2921 		       (int) sizeof(es->s_first_error_func),
2922 		       es->s_first_error_func,
2923 		       le32_to_cpu(es->s_first_error_line));
2924 		if (es->s_first_error_ino)
2925 			printk(KERN_CONT ": inode %u",
2926 			       le32_to_cpu(es->s_first_error_ino));
2927 		if (es->s_first_error_block)
2928 			printk(KERN_CONT ": block %llu", (unsigned long long)
2929 			       le64_to_cpu(es->s_first_error_block));
2930 		printk(KERN_CONT "\n");
2931 	}
2932 	if (es->s_last_error_time) {
2933 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
2934 		       sb->s_id,
2935 		       ext4_get_tstamp(es, s_last_error_time),
2936 		       (int) sizeof(es->s_last_error_func),
2937 		       es->s_last_error_func,
2938 		       le32_to_cpu(es->s_last_error_line));
2939 		if (es->s_last_error_ino)
2940 			printk(KERN_CONT ": inode %u",
2941 			       le32_to_cpu(es->s_last_error_ino));
2942 		if (es->s_last_error_block)
2943 			printk(KERN_CONT ": block %llu", (unsigned long long)
2944 			       le64_to_cpu(es->s_last_error_block));
2945 		printk(KERN_CONT "\n");
2946 	}
2947 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2948 }
2949 
2950 /* Find next suitable group and run ext4_init_inode_table */
2951 static int ext4_run_li_request(struct ext4_li_request *elr)
2952 {
2953 	struct ext4_group_desc *gdp = NULL;
2954 	ext4_group_t group, ngroups;
2955 	struct super_block *sb;
2956 	unsigned long timeout = 0;
2957 	int ret = 0;
2958 
2959 	sb = elr->lr_super;
2960 	ngroups = EXT4_SB(sb)->s_groups_count;
2961 
2962 	for (group = elr->lr_next_group; group < ngroups; group++) {
2963 		gdp = ext4_get_group_desc(sb, group, NULL);
2964 		if (!gdp) {
2965 			ret = 1;
2966 			break;
2967 		}
2968 
2969 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2970 			break;
2971 	}
2972 
2973 	if (group >= ngroups)
2974 		ret = 1;
2975 
2976 	if (!ret) {
2977 		timeout = jiffies;
2978 		ret = ext4_init_inode_table(sb, group,
2979 					    elr->lr_timeout ? 0 : 1);
2980 		if (elr->lr_timeout == 0) {
2981 			timeout = (jiffies - timeout) *
2982 				  elr->lr_sbi->s_li_wait_mult;
2983 			elr->lr_timeout = timeout;
2984 		}
2985 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2986 		elr->lr_next_group = group + 1;
2987 	}
2988 	return ret;
2989 }
2990 
2991 /*
2992  * Remove lr_request from the list_request and free the
2993  * request structure. Should be called with li_list_mtx held
2994  */
2995 static void ext4_remove_li_request(struct ext4_li_request *elr)
2996 {
2997 	struct ext4_sb_info *sbi;
2998 
2999 	if (!elr)
3000 		return;
3001 
3002 	sbi = elr->lr_sbi;
3003 
3004 	list_del(&elr->lr_request);
3005 	sbi->s_li_request = NULL;
3006 	kfree(elr);
3007 }
3008 
3009 static void ext4_unregister_li_request(struct super_block *sb)
3010 {
3011 	mutex_lock(&ext4_li_mtx);
3012 	if (!ext4_li_info) {
3013 		mutex_unlock(&ext4_li_mtx);
3014 		return;
3015 	}
3016 
3017 	mutex_lock(&ext4_li_info->li_list_mtx);
3018 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3019 	mutex_unlock(&ext4_li_info->li_list_mtx);
3020 	mutex_unlock(&ext4_li_mtx);
3021 }
3022 
3023 static struct task_struct *ext4_lazyinit_task;
3024 
3025 /*
3026  * This is the function where ext4lazyinit thread lives. It walks
3027  * through the request list searching for next scheduled filesystem.
3028  * When such a fs is found, run the lazy initialization request
3029  * (ext4_rn_li_request) and keep track of the time spend in this
3030  * function. Based on that time we compute next schedule time of
3031  * the request. When walking through the list is complete, compute
3032  * next waking time and put itself into sleep.
3033  */
3034 static int ext4_lazyinit_thread(void *arg)
3035 {
3036 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3037 	struct list_head *pos, *n;
3038 	struct ext4_li_request *elr;
3039 	unsigned long next_wakeup, cur;
3040 
3041 	BUG_ON(NULL == eli);
3042 
3043 cont_thread:
3044 	while (true) {
3045 		next_wakeup = MAX_JIFFY_OFFSET;
3046 
3047 		mutex_lock(&eli->li_list_mtx);
3048 		if (list_empty(&eli->li_request_list)) {
3049 			mutex_unlock(&eli->li_list_mtx);
3050 			goto exit_thread;
3051 		}
3052 		list_for_each_safe(pos, n, &eli->li_request_list) {
3053 			int err = 0;
3054 			int progress = 0;
3055 			elr = list_entry(pos, struct ext4_li_request,
3056 					 lr_request);
3057 
3058 			if (time_before(jiffies, elr->lr_next_sched)) {
3059 				if (time_before(elr->lr_next_sched, next_wakeup))
3060 					next_wakeup = elr->lr_next_sched;
3061 				continue;
3062 			}
3063 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3064 				if (sb_start_write_trylock(elr->lr_super)) {
3065 					progress = 1;
3066 					/*
3067 					 * We hold sb->s_umount, sb can not
3068 					 * be removed from the list, it is
3069 					 * now safe to drop li_list_mtx
3070 					 */
3071 					mutex_unlock(&eli->li_list_mtx);
3072 					err = ext4_run_li_request(elr);
3073 					sb_end_write(elr->lr_super);
3074 					mutex_lock(&eli->li_list_mtx);
3075 					n = pos->next;
3076 				}
3077 				up_read((&elr->lr_super->s_umount));
3078 			}
3079 			/* error, remove the lazy_init job */
3080 			if (err) {
3081 				ext4_remove_li_request(elr);
3082 				continue;
3083 			}
3084 			if (!progress) {
3085 				elr->lr_next_sched = jiffies +
3086 					(prandom_u32()
3087 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3088 			}
3089 			if (time_before(elr->lr_next_sched, next_wakeup))
3090 				next_wakeup = elr->lr_next_sched;
3091 		}
3092 		mutex_unlock(&eli->li_list_mtx);
3093 
3094 		try_to_freeze();
3095 
3096 		cur = jiffies;
3097 		if ((time_after_eq(cur, next_wakeup)) ||
3098 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3099 			cond_resched();
3100 			continue;
3101 		}
3102 
3103 		schedule_timeout_interruptible(next_wakeup - cur);
3104 
3105 		if (kthread_should_stop()) {
3106 			ext4_clear_request_list();
3107 			goto exit_thread;
3108 		}
3109 	}
3110 
3111 exit_thread:
3112 	/*
3113 	 * It looks like the request list is empty, but we need
3114 	 * to check it under the li_list_mtx lock, to prevent any
3115 	 * additions into it, and of course we should lock ext4_li_mtx
3116 	 * to atomically free the list and ext4_li_info, because at
3117 	 * this point another ext4 filesystem could be registering
3118 	 * new one.
3119 	 */
3120 	mutex_lock(&ext4_li_mtx);
3121 	mutex_lock(&eli->li_list_mtx);
3122 	if (!list_empty(&eli->li_request_list)) {
3123 		mutex_unlock(&eli->li_list_mtx);
3124 		mutex_unlock(&ext4_li_mtx);
3125 		goto cont_thread;
3126 	}
3127 	mutex_unlock(&eli->li_list_mtx);
3128 	kfree(ext4_li_info);
3129 	ext4_li_info = NULL;
3130 	mutex_unlock(&ext4_li_mtx);
3131 
3132 	return 0;
3133 }
3134 
3135 static void ext4_clear_request_list(void)
3136 {
3137 	struct list_head *pos, *n;
3138 	struct ext4_li_request *elr;
3139 
3140 	mutex_lock(&ext4_li_info->li_list_mtx);
3141 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3142 		elr = list_entry(pos, struct ext4_li_request,
3143 				 lr_request);
3144 		ext4_remove_li_request(elr);
3145 	}
3146 	mutex_unlock(&ext4_li_info->li_list_mtx);
3147 }
3148 
3149 static int ext4_run_lazyinit_thread(void)
3150 {
3151 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3152 					 ext4_li_info, "ext4lazyinit");
3153 	if (IS_ERR(ext4_lazyinit_task)) {
3154 		int err = PTR_ERR(ext4_lazyinit_task);
3155 		ext4_clear_request_list();
3156 		kfree(ext4_li_info);
3157 		ext4_li_info = NULL;
3158 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3159 				 "initialization thread\n",
3160 				 err);
3161 		return err;
3162 	}
3163 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3164 	return 0;
3165 }
3166 
3167 /*
3168  * Check whether it make sense to run itable init. thread or not.
3169  * If there is at least one uninitialized inode table, return
3170  * corresponding group number, else the loop goes through all
3171  * groups and return total number of groups.
3172  */
3173 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3174 {
3175 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3176 	struct ext4_group_desc *gdp = NULL;
3177 
3178 	if (!ext4_has_group_desc_csum(sb))
3179 		return ngroups;
3180 
3181 	for (group = 0; group < ngroups; group++) {
3182 		gdp = ext4_get_group_desc(sb, group, NULL);
3183 		if (!gdp)
3184 			continue;
3185 
3186 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3187 			break;
3188 	}
3189 
3190 	return group;
3191 }
3192 
3193 static int ext4_li_info_new(void)
3194 {
3195 	struct ext4_lazy_init *eli = NULL;
3196 
3197 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3198 	if (!eli)
3199 		return -ENOMEM;
3200 
3201 	INIT_LIST_HEAD(&eli->li_request_list);
3202 	mutex_init(&eli->li_list_mtx);
3203 
3204 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3205 
3206 	ext4_li_info = eli;
3207 
3208 	return 0;
3209 }
3210 
3211 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3212 					    ext4_group_t start)
3213 {
3214 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3215 	struct ext4_li_request *elr;
3216 
3217 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3218 	if (!elr)
3219 		return NULL;
3220 
3221 	elr->lr_super = sb;
3222 	elr->lr_sbi = sbi;
3223 	elr->lr_next_group = start;
3224 
3225 	/*
3226 	 * Randomize first schedule time of the request to
3227 	 * spread the inode table initialization requests
3228 	 * better.
3229 	 */
3230 	elr->lr_next_sched = jiffies + (prandom_u32() %
3231 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3232 	return elr;
3233 }
3234 
3235 int ext4_register_li_request(struct super_block *sb,
3236 			     ext4_group_t first_not_zeroed)
3237 {
3238 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3239 	struct ext4_li_request *elr = NULL;
3240 	ext4_group_t ngroups = sbi->s_groups_count;
3241 	int ret = 0;
3242 
3243 	mutex_lock(&ext4_li_mtx);
3244 	if (sbi->s_li_request != NULL) {
3245 		/*
3246 		 * Reset timeout so it can be computed again, because
3247 		 * s_li_wait_mult might have changed.
3248 		 */
3249 		sbi->s_li_request->lr_timeout = 0;
3250 		goto out;
3251 	}
3252 
3253 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3254 	    !test_opt(sb, INIT_INODE_TABLE))
3255 		goto out;
3256 
3257 	elr = ext4_li_request_new(sb, first_not_zeroed);
3258 	if (!elr) {
3259 		ret = -ENOMEM;
3260 		goto out;
3261 	}
3262 
3263 	if (NULL == ext4_li_info) {
3264 		ret = ext4_li_info_new();
3265 		if (ret)
3266 			goto out;
3267 	}
3268 
3269 	mutex_lock(&ext4_li_info->li_list_mtx);
3270 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3271 	mutex_unlock(&ext4_li_info->li_list_mtx);
3272 
3273 	sbi->s_li_request = elr;
3274 	/*
3275 	 * set elr to NULL here since it has been inserted to
3276 	 * the request_list and the removal and free of it is
3277 	 * handled by ext4_clear_request_list from now on.
3278 	 */
3279 	elr = NULL;
3280 
3281 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3282 		ret = ext4_run_lazyinit_thread();
3283 		if (ret)
3284 			goto out;
3285 	}
3286 out:
3287 	mutex_unlock(&ext4_li_mtx);
3288 	if (ret)
3289 		kfree(elr);
3290 	return ret;
3291 }
3292 
3293 /*
3294  * We do not need to lock anything since this is called on
3295  * module unload.
3296  */
3297 static void ext4_destroy_lazyinit_thread(void)
3298 {
3299 	/*
3300 	 * If thread exited earlier
3301 	 * there's nothing to be done.
3302 	 */
3303 	if (!ext4_li_info || !ext4_lazyinit_task)
3304 		return;
3305 
3306 	kthread_stop(ext4_lazyinit_task);
3307 }
3308 
3309 static int set_journal_csum_feature_set(struct super_block *sb)
3310 {
3311 	int ret = 1;
3312 	int compat, incompat;
3313 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3314 
3315 	if (ext4_has_metadata_csum(sb)) {
3316 		/* journal checksum v3 */
3317 		compat = 0;
3318 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3319 	} else {
3320 		/* journal checksum v1 */
3321 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3322 		incompat = 0;
3323 	}
3324 
3325 	jbd2_journal_clear_features(sbi->s_journal,
3326 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3327 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3328 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3329 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3330 		ret = jbd2_journal_set_features(sbi->s_journal,
3331 				compat, 0,
3332 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3333 				incompat);
3334 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3335 		ret = jbd2_journal_set_features(sbi->s_journal,
3336 				compat, 0,
3337 				incompat);
3338 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3339 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3340 	} else {
3341 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3342 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3343 	}
3344 
3345 	return ret;
3346 }
3347 
3348 /*
3349  * Note: calculating the overhead so we can be compatible with
3350  * historical BSD practice is quite difficult in the face of
3351  * clusters/bigalloc.  This is because multiple metadata blocks from
3352  * different block group can end up in the same allocation cluster.
3353  * Calculating the exact overhead in the face of clustered allocation
3354  * requires either O(all block bitmaps) in memory or O(number of block
3355  * groups**2) in time.  We will still calculate the superblock for
3356  * older file systems --- and if we come across with a bigalloc file
3357  * system with zero in s_overhead_clusters the estimate will be close to
3358  * correct especially for very large cluster sizes --- but for newer
3359  * file systems, it's better to calculate this figure once at mkfs
3360  * time, and store it in the superblock.  If the superblock value is
3361  * present (even for non-bigalloc file systems), we will use it.
3362  */
3363 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3364 			  char *buf)
3365 {
3366 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3367 	struct ext4_group_desc	*gdp;
3368 	ext4_fsblk_t		first_block, last_block, b;
3369 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3370 	int			s, j, count = 0;
3371 
3372 	if (!ext4_has_feature_bigalloc(sb))
3373 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3374 			sbi->s_itb_per_group + 2);
3375 
3376 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3377 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3378 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3379 	for (i = 0; i < ngroups; i++) {
3380 		gdp = ext4_get_group_desc(sb, i, NULL);
3381 		b = ext4_block_bitmap(sb, gdp);
3382 		if (b >= first_block && b <= last_block) {
3383 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3384 			count++;
3385 		}
3386 		b = ext4_inode_bitmap(sb, gdp);
3387 		if (b >= first_block && b <= last_block) {
3388 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3389 			count++;
3390 		}
3391 		b = ext4_inode_table(sb, gdp);
3392 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3393 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3394 				int c = EXT4_B2C(sbi, b - first_block);
3395 				ext4_set_bit(c, buf);
3396 				count++;
3397 			}
3398 		if (i != grp)
3399 			continue;
3400 		s = 0;
3401 		if (ext4_bg_has_super(sb, grp)) {
3402 			ext4_set_bit(s++, buf);
3403 			count++;
3404 		}
3405 		j = ext4_bg_num_gdb(sb, grp);
3406 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3407 			ext4_error(sb, "Invalid number of block group "
3408 				   "descriptor blocks: %d", j);
3409 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3410 		}
3411 		count += j;
3412 		for (; j > 0; j--)
3413 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3414 	}
3415 	if (!count)
3416 		return 0;
3417 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3418 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3419 }
3420 
3421 /*
3422  * Compute the overhead and stash it in sbi->s_overhead
3423  */
3424 int ext4_calculate_overhead(struct super_block *sb)
3425 {
3426 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3427 	struct ext4_super_block *es = sbi->s_es;
3428 	struct inode *j_inode;
3429 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3430 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3431 	ext4_fsblk_t overhead = 0;
3432 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3433 
3434 	if (!buf)
3435 		return -ENOMEM;
3436 
3437 	/*
3438 	 * Compute the overhead (FS structures).  This is constant
3439 	 * for a given filesystem unless the number of block groups
3440 	 * changes so we cache the previous value until it does.
3441 	 */
3442 
3443 	/*
3444 	 * All of the blocks before first_data_block are overhead
3445 	 */
3446 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3447 
3448 	/*
3449 	 * Add the overhead found in each block group
3450 	 */
3451 	for (i = 0; i < ngroups; i++) {
3452 		int blks;
3453 
3454 		blks = count_overhead(sb, i, buf);
3455 		overhead += blks;
3456 		if (blks)
3457 			memset(buf, 0, PAGE_SIZE);
3458 		cond_resched();
3459 	}
3460 
3461 	/*
3462 	 * Add the internal journal blocks whether the journal has been
3463 	 * loaded or not
3464 	 */
3465 	if (sbi->s_journal && !sbi->journal_bdev)
3466 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3467 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3468 		j_inode = ext4_get_journal_inode(sb, j_inum);
3469 		if (j_inode) {
3470 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3471 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3472 			iput(j_inode);
3473 		} else {
3474 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3475 		}
3476 	}
3477 	sbi->s_overhead = overhead;
3478 	smp_wmb();
3479 	free_page((unsigned long) buf);
3480 	return 0;
3481 }
3482 
3483 static void ext4_set_resv_clusters(struct super_block *sb)
3484 {
3485 	ext4_fsblk_t resv_clusters;
3486 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3487 
3488 	/*
3489 	 * There's no need to reserve anything when we aren't using extents.
3490 	 * The space estimates are exact, there are no unwritten extents,
3491 	 * hole punching doesn't need new metadata... This is needed especially
3492 	 * to keep ext2/3 backward compatibility.
3493 	 */
3494 	if (!ext4_has_feature_extents(sb))
3495 		return;
3496 	/*
3497 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3498 	 * This should cover the situations where we can not afford to run
3499 	 * out of space like for example punch hole, or converting
3500 	 * unwritten extents in delalloc path. In most cases such
3501 	 * allocation would require 1, or 2 blocks, higher numbers are
3502 	 * very rare.
3503 	 */
3504 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3505 			 sbi->s_cluster_bits);
3506 
3507 	do_div(resv_clusters, 50);
3508 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3509 
3510 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3511 }
3512 
3513 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3514 {
3515 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3516 	char *orig_data = kstrdup(data, GFP_KERNEL);
3517 	struct buffer_head *bh;
3518 	struct ext4_super_block *es = NULL;
3519 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3520 	ext4_fsblk_t block;
3521 	ext4_fsblk_t sb_block = get_sb_block(&data);
3522 	ext4_fsblk_t logical_sb_block;
3523 	unsigned long offset = 0;
3524 	unsigned long journal_devnum = 0;
3525 	unsigned long def_mount_opts;
3526 	struct inode *root;
3527 	const char *descr;
3528 	int ret = -ENOMEM;
3529 	int blocksize, clustersize;
3530 	unsigned int db_count;
3531 	unsigned int i;
3532 	int needs_recovery, has_huge_files, has_bigalloc;
3533 	__u64 blocks_count;
3534 	int err = 0;
3535 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3536 	ext4_group_t first_not_zeroed;
3537 
3538 	if ((data && !orig_data) || !sbi)
3539 		goto out_free_base;
3540 
3541 	sbi->s_daxdev = dax_dev;
3542 	sbi->s_blockgroup_lock =
3543 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3544 	if (!sbi->s_blockgroup_lock)
3545 		goto out_free_base;
3546 
3547 	sb->s_fs_info = sbi;
3548 	sbi->s_sb = sb;
3549 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3550 	sbi->s_sb_block = sb_block;
3551 	if (sb->s_bdev->bd_part)
3552 		sbi->s_sectors_written_start =
3553 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3554 
3555 	/* Cleanup superblock name */
3556 	strreplace(sb->s_id, '/', '!');
3557 
3558 	/* -EINVAL is default */
3559 	ret = -EINVAL;
3560 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3561 	if (!blocksize) {
3562 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3563 		goto out_fail;
3564 	}
3565 
3566 	/*
3567 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3568 	 * block sizes.  We need to calculate the offset from buffer start.
3569 	 */
3570 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3571 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3572 		offset = do_div(logical_sb_block, blocksize);
3573 	} else {
3574 		logical_sb_block = sb_block;
3575 	}
3576 
3577 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3578 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3579 		goto out_fail;
3580 	}
3581 	/*
3582 	 * Note: s_es must be initialized as soon as possible because
3583 	 *       some ext4 macro-instructions depend on its value
3584 	 */
3585 	es = (struct ext4_super_block *) (bh->b_data + offset);
3586 	sbi->s_es = es;
3587 	sb->s_magic = le16_to_cpu(es->s_magic);
3588 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3589 		goto cantfind_ext4;
3590 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3591 
3592 	/* Warn if metadata_csum and gdt_csum are both set. */
3593 	if (ext4_has_feature_metadata_csum(sb) &&
3594 	    ext4_has_feature_gdt_csum(sb))
3595 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3596 			     "redundant flags; please run fsck.");
3597 
3598 	/* Check for a known checksum algorithm */
3599 	if (!ext4_verify_csum_type(sb, es)) {
3600 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3601 			 "unknown checksum algorithm.");
3602 		silent = 1;
3603 		goto cantfind_ext4;
3604 	}
3605 
3606 	/* Load the checksum driver */
3607 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3608 	if (IS_ERR(sbi->s_chksum_driver)) {
3609 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3610 		ret = PTR_ERR(sbi->s_chksum_driver);
3611 		sbi->s_chksum_driver = NULL;
3612 		goto failed_mount;
3613 	}
3614 
3615 	/* Check superblock checksum */
3616 	if (!ext4_superblock_csum_verify(sb, es)) {
3617 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3618 			 "invalid superblock checksum.  Run e2fsck?");
3619 		silent = 1;
3620 		ret = -EFSBADCRC;
3621 		goto cantfind_ext4;
3622 	}
3623 
3624 	/* Precompute checksum seed for all metadata */
3625 	if (ext4_has_feature_csum_seed(sb))
3626 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3627 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3628 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3629 					       sizeof(es->s_uuid));
3630 
3631 	/* Set defaults before we parse the mount options */
3632 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3633 	set_opt(sb, INIT_INODE_TABLE);
3634 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3635 		set_opt(sb, DEBUG);
3636 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3637 		set_opt(sb, GRPID);
3638 	if (def_mount_opts & EXT4_DEFM_UID16)
3639 		set_opt(sb, NO_UID32);
3640 	/* xattr user namespace & acls are now defaulted on */
3641 	set_opt(sb, XATTR_USER);
3642 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3643 	set_opt(sb, POSIX_ACL);
3644 #endif
3645 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3646 	if (ext4_has_metadata_csum(sb))
3647 		set_opt(sb, JOURNAL_CHECKSUM);
3648 
3649 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3650 		set_opt(sb, JOURNAL_DATA);
3651 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3652 		set_opt(sb, ORDERED_DATA);
3653 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3654 		set_opt(sb, WRITEBACK_DATA);
3655 
3656 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3657 		set_opt(sb, ERRORS_PANIC);
3658 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3659 		set_opt(sb, ERRORS_CONT);
3660 	else
3661 		set_opt(sb, ERRORS_RO);
3662 	/* block_validity enabled by default; disable with noblock_validity */
3663 	set_opt(sb, BLOCK_VALIDITY);
3664 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3665 		set_opt(sb, DISCARD);
3666 
3667 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3668 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3669 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3670 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3671 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3672 
3673 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3674 		set_opt(sb, BARRIER);
3675 
3676 	/*
3677 	 * enable delayed allocation by default
3678 	 * Use -o nodelalloc to turn it off
3679 	 */
3680 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3681 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3682 		set_opt(sb, DELALLOC);
3683 
3684 	/*
3685 	 * set default s_li_wait_mult for lazyinit, for the case there is
3686 	 * no mount option specified.
3687 	 */
3688 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3689 
3690 	if (sbi->s_es->s_mount_opts[0]) {
3691 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3692 					      sizeof(sbi->s_es->s_mount_opts),
3693 					      GFP_KERNEL);
3694 		if (!s_mount_opts)
3695 			goto failed_mount;
3696 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3697 				   &journal_ioprio, 0)) {
3698 			ext4_msg(sb, KERN_WARNING,
3699 				 "failed to parse options in superblock: %s",
3700 				 s_mount_opts);
3701 		}
3702 		kfree(s_mount_opts);
3703 	}
3704 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3705 	if (!parse_options((char *) data, sb, &journal_devnum,
3706 			   &journal_ioprio, 0))
3707 		goto failed_mount;
3708 
3709 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3710 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3711 			    "with data=journal disables delayed "
3712 			    "allocation and O_DIRECT support!\n");
3713 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3714 			ext4_msg(sb, KERN_ERR, "can't mount with "
3715 				 "both data=journal and delalloc");
3716 			goto failed_mount;
3717 		}
3718 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3719 			ext4_msg(sb, KERN_ERR, "can't mount with "
3720 				 "both data=journal and dioread_nolock");
3721 			goto failed_mount;
3722 		}
3723 		if (test_opt(sb, DAX)) {
3724 			ext4_msg(sb, KERN_ERR, "can't mount with "
3725 				 "both data=journal and dax");
3726 			goto failed_mount;
3727 		}
3728 		if (ext4_has_feature_encrypt(sb)) {
3729 			ext4_msg(sb, KERN_WARNING,
3730 				 "encrypted files will use data=ordered "
3731 				 "instead of data journaling mode");
3732 		}
3733 		if (test_opt(sb, DELALLOC))
3734 			clear_opt(sb, DELALLOC);
3735 	} else {
3736 		sb->s_iflags |= SB_I_CGROUPWB;
3737 	}
3738 
3739 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3740 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3741 
3742 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3743 	    (ext4_has_compat_features(sb) ||
3744 	     ext4_has_ro_compat_features(sb) ||
3745 	     ext4_has_incompat_features(sb)))
3746 		ext4_msg(sb, KERN_WARNING,
3747 		       "feature flags set on rev 0 fs, "
3748 		       "running e2fsck is recommended");
3749 
3750 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3751 		set_opt2(sb, HURD_COMPAT);
3752 		if (ext4_has_feature_64bit(sb)) {
3753 			ext4_msg(sb, KERN_ERR,
3754 				 "The Hurd can't support 64-bit file systems");
3755 			goto failed_mount;
3756 		}
3757 
3758 		/*
3759 		 * ea_inode feature uses l_i_version field which is not
3760 		 * available in HURD_COMPAT mode.
3761 		 */
3762 		if (ext4_has_feature_ea_inode(sb)) {
3763 			ext4_msg(sb, KERN_ERR,
3764 				 "ea_inode feature is not supported for Hurd");
3765 			goto failed_mount;
3766 		}
3767 	}
3768 
3769 	if (IS_EXT2_SB(sb)) {
3770 		if (ext2_feature_set_ok(sb))
3771 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3772 				 "using the ext4 subsystem");
3773 		else {
3774 			/*
3775 			 * If we're probing be silent, if this looks like
3776 			 * it's actually an ext[34] filesystem.
3777 			 */
3778 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3779 				goto failed_mount;
3780 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3781 				 "to feature incompatibilities");
3782 			goto failed_mount;
3783 		}
3784 	}
3785 
3786 	if (IS_EXT3_SB(sb)) {
3787 		if (ext3_feature_set_ok(sb))
3788 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3789 				 "using the ext4 subsystem");
3790 		else {
3791 			/*
3792 			 * If we're probing be silent, if this looks like
3793 			 * it's actually an ext4 filesystem.
3794 			 */
3795 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3796 				goto failed_mount;
3797 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3798 				 "to feature incompatibilities");
3799 			goto failed_mount;
3800 		}
3801 	}
3802 
3803 	/*
3804 	 * Check feature flags regardless of the revision level, since we
3805 	 * previously didn't change the revision level when setting the flags,
3806 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3807 	 */
3808 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3809 		goto failed_mount;
3810 
3811 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3812 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3813 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3814 		ext4_msg(sb, KERN_ERR,
3815 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3816 			 blocksize, le32_to_cpu(es->s_log_block_size));
3817 		goto failed_mount;
3818 	}
3819 	if (le32_to_cpu(es->s_log_block_size) >
3820 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3821 		ext4_msg(sb, KERN_ERR,
3822 			 "Invalid log block size: %u",
3823 			 le32_to_cpu(es->s_log_block_size));
3824 		goto failed_mount;
3825 	}
3826 	if (le32_to_cpu(es->s_log_cluster_size) >
3827 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3828 		ext4_msg(sb, KERN_ERR,
3829 			 "Invalid log cluster size: %u",
3830 			 le32_to_cpu(es->s_log_cluster_size));
3831 		goto failed_mount;
3832 	}
3833 
3834 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3835 		ext4_msg(sb, KERN_ERR,
3836 			 "Number of reserved GDT blocks insanely large: %d",
3837 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3838 		goto failed_mount;
3839 	}
3840 
3841 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3842 		if (ext4_has_feature_inline_data(sb)) {
3843 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3844 					" that may contain inline data");
3845 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
3846 		}
3847 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
3848 			ext4_msg(sb, KERN_ERR,
3849 				"DAX unsupported by block device. Turning off DAX.");
3850 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
3851 		}
3852 	}
3853 
3854 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3855 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3856 			 es->s_encryption_level);
3857 		goto failed_mount;
3858 	}
3859 
3860 	if (sb->s_blocksize != blocksize) {
3861 		/* Validate the filesystem blocksize */
3862 		if (!sb_set_blocksize(sb, blocksize)) {
3863 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3864 					blocksize);
3865 			goto failed_mount;
3866 		}
3867 
3868 		brelse(bh);
3869 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3870 		offset = do_div(logical_sb_block, blocksize);
3871 		bh = sb_bread_unmovable(sb, logical_sb_block);
3872 		if (!bh) {
3873 			ext4_msg(sb, KERN_ERR,
3874 			       "Can't read superblock on 2nd try");
3875 			goto failed_mount;
3876 		}
3877 		es = (struct ext4_super_block *)(bh->b_data + offset);
3878 		sbi->s_es = es;
3879 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3880 			ext4_msg(sb, KERN_ERR,
3881 			       "Magic mismatch, very weird!");
3882 			goto failed_mount;
3883 		}
3884 	}
3885 
3886 	has_huge_files = ext4_has_feature_huge_file(sb);
3887 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3888 						      has_huge_files);
3889 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3890 
3891 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3892 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3893 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3894 	} else {
3895 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3896 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3897 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3898 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3899 				 sbi->s_first_ino);
3900 			goto failed_mount;
3901 		}
3902 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3903 		    (!is_power_of_2(sbi->s_inode_size)) ||
3904 		    (sbi->s_inode_size > blocksize)) {
3905 			ext4_msg(sb, KERN_ERR,
3906 			       "unsupported inode size: %d",
3907 			       sbi->s_inode_size);
3908 			goto failed_mount;
3909 		}
3910 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3911 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3912 	}
3913 
3914 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3915 	if (ext4_has_feature_64bit(sb)) {
3916 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3917 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3918 		    !is_power_of_2(sbi->s_desc_size)) {
3919 			ext4_msg(sb, KERN_ERR,
3920 			       "unsupported descriptor size %lu",
3921 			       sbi->s_desc_size);
3922 			goto failed_mount;
3923 		}
3924 	} else
3925 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3926 
3927 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3928 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3929 
3930 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3931 	if (sbi->s_inodes_per_block == 0)
3932 		goto cantfind_ext4;
3933 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3934 	    sbi->s_inodes_per_group > blocksize * 8) {
3935 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3936 			 sbi->s_blocks_per_group);
3937 		goto failed_mount;
3938 	}
3939 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3940 					sbi->s_inodes_per_block;
3941 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3942 	sbi->s_sbh = bh;
3943 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3944 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3945 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3946 
3947 	for (i = 0; i < 4; i++)
3948 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3949 	sbi->s_def_hash_version = es->s_def_hash_version;
3950 	if (ext4_has_feature_dir_index(sb)) {
3951 		i = le32_to_cpu(es->s_flags);
3952 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3953 			sbi->s_hash_unsigned = 3;
3954 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3955 #ifdef __CHAR_UNSIGNED__
3956 			if (!sb_rdonly(sb))
3957 				es->s_flags |=
3958 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3959 			sbi->s_hash_unsigned = 3;
3960 #else
3961 			if (!sb_rdonly(sb))
3962 				es->s_flags |=
3963 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3964 #endif
3965 		}
3966 	}
3967 
3968 	/* Handle clustersize */
3969 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3970 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3971 	if (has_bigalloc) {
3972 		if (clustersize < blocksize) {
3973 			ext4_msg(sb, KERN_ERR,
3974 				 "cluster size (%d) smaller than "
3975 				 "block size (%d)", clustersize, blocksize);
3976 			goto failed_mount;
3977 		}
3978 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3979 			le32_to_cpu(es->s_log_block_size);
3980 		sbi->s_clusters_per_group =
3981 			le32_to_cpu(es->s_clusters_per_group);
3982 		if (sbi->s_clusters_per_group > blocksize * 8) {
3983 			ext4_msg(sb, KERN_ERR,
3984 				 "#clusters per group too big: %lu",
3985 				 sbi->s_clusters_per_group);
3986 			goto failed_mount;
3987 		}
3988 		if (sbi->s_blocks_per_group !=
3989 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3990 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3991 				 "clusters per group (%lu) inconsistent",
3992 				 sbi->s_blocks_per_group,
3993 				 sbi->s_clusters_per_group);
3994 			goto failed_mount;
3995 		}
3996 	} else {
3997 		if (clustersize != blocksize) {
3998 			ext4_msg(sb, KERN_ERR,
3999 				 "fragment/cluster size (%d) != "
4000 				 "block size (%d)", clustersize, blocksize);
4001 			goto failed_mount;
4002 		}
4003 		if (sbi->s_blocks_per_group > blocksize * 8) {
4004 			ext4_msg(sb, KERN_ERR,
4005 				 "#blocks per group too big: %lu",
4006 				 sbi->s_blocks_per_group);
4007 			goto failed_mount;
4008 		}
4009 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4010 		sbi->s_cluster_bits = 0;
4011 	}
4012 	sbi->s_cluster_ratio = clustersize / blocksize;
4013 
4014 	/* Do we have standard group size of clustersize * 8 blocks ? */
4015 	if (sbi->s_blocks_per_group == clustersize << 3)
4016 		set_opt2(sb, STD_GROUP_SIZE);
4017 
4018 	/*
4019 	 * Test whether we have more sectors than will fit in sector_t,
4020 	 * and whether the max offset is addressable by the page cache.
4021 	 */
4022 	err = generic_check_addressable(sb->s_blocksize_bits,
4023 					ext4_blocks_count(es));
4024 	if (err) {
4025 		ext4_msg(sb, KERN_ERR, "filesystem"
4026 			 " too large to mount safely on this system");
4027 		if (sizeof(sector_t) < 8)
4028 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
4029 		goto failed_mount;
4030 	}
4031 
4032 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4033 		goto cantfind_ext4;
4034 
4035 	/* check blocks count against device size */
4036 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4037 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4038 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4039 		       "exceeds size of device (%llu blocks)",
4040 		       ext4_blocks_count(es), blocks_count);
4041 		goto failed_mount;
4042 	}
4043 
4044 	/*
4045 	 * It makes no sense for the first data block to be beyond the end
4046 	 * of the filesystem.
4047 	 */
4048 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4049 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4050 			 "block %u is beyond end of filesystem (%llu)",
4051 			 le32_to_cpu(es->s_first_data_block),
4052 			 ext4_blocks_count(es));
4053 		goto failed_mount;
4054 	}
4055 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4056 	    (sbi->s_cluster_ratio == 1)) {
4057 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4058 			 "block is 0 with a 1k block and cluster size");
4059 		goto failed_mount;
4060 	}
4061 
4062 	blocks_count = (ext4_blocks_count(es) -
4063 			le32_to_cpu(es->s_first_data_block) +
4064 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4065 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4066 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4067 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4068 		       "(block count %llu, first data block %u, "
4069 		       "blocks per group %lu)", sbi->s_groups_count,
4070 		       ext4_blocks_count(es),
4071 		       le32_to_cpu(es->s_first_data_block),
4072 		       EXT4_BLOCKS_PER_GROUP(sb));
4073 		goto failed_mount;
4074 	}
4075 	sbi->s_groups_count = blocks_count;
4076 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4077 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4078 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4079 		   EXT4_DESC_PER_BLOCK(sb);
4080 	if (ext4_has_feature_meta_bg(sb)) {
4081 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4082 			ext4_msg(sb, KERN_WARNING,
4083 				 "first meta block group too large: %u "
4084 				 "(group descriptor block count %u)",
4085 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4086 			goto failed_mount;
4087 		}
4088 	}
4089 	sbi->s_group_desc = kvmalloc_array(db_count,
4090 					   sizeof(struct buffer_head *),
4091 					   GFP_KERNEL);
4092 	if (sbi->s_group_desc == NULL) {
4093 		ext4_msg(sb, KERN_ERR, "not enough memory");
4094 		ret = -ENOMEM;
4095 		goto failed_mount;
4096 	}
4097 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4098 	    le32_to_cpu(es->s_inodes_count)) {
4099 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4100 			 le32_to_cpu(es->s_inodes_count),
4101 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4102 		ret = -EINVAL;
4103 		goto failed_mount;
4104 	}
4105 
4106 	bgl_lock_init(sbi->s_blockgroup_lock);
4107 
4108 	/* Pre-read the descriptors into the buffer cache */
4109 	for (i = 0; i < db_count; i++) {
4110 		block = descriptor_loc(sb, logical_sb_block, i);
4111 		sb_breadahead(sb, block);
4112 	}
4113 
4114 	for (i = 0; i < db_count; i++) {
4115 		block = descriptor_loc(sb, logical_sb_block, i);
4116 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4117 		if (!sbi->s_group_desc[i]) {
4118 			ext4_msg(sb, KERN_ERR,
4119 			       "can't read group descriptor %d", i);
4120 			db_count = i;
4121 			goto failed_mount2;
4122 		}
4123 	}
4124 	sbi->s_gdb_count = db_count;
4125 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4126 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4127 		ret = -EFSCORRUPTED;
4128 		goto failed_mount2;
4129 	}
4130 
4131 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4132 
4133 	/* Register extent status tree shrinker */
4134 	if (ext4_es_register_shrinker(sbi))
4135 		goto failed_mount3;
4136 
4137 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4138 	sbi->s_extent_max_zeroout_kb = 32;
4139 
4140 	/*
4141 	 * set up enough so that it can read an inode
4142 	 */
4143 	sb->s_op = &ext4_sops;
4144 	sb->s_export_op = &ext4_export_ops;
4145 	sb->s_xattr = ext4_xattr_handlers;
4146 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4147 	sb->s_cop = &ext4_cryptops;
4148 #endif
4149 #ifdef CONFIG_QUOTA
4150 	sb->dq_op = &ext4_quota_operations;
4151 	if (ext4_has_feature_quota(sb))
4152 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4153 	else
4154 		sb->s_qcop = &ext4_qctl_operations;
4155 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4156 #endif
4157 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4158 
4159 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4160 	mutex_init(&sbi->s_orphan_lock);
4161 
4162 	sb->s_root = NULL;
4163 
4164 	needs_recovery = (es->s_last_orphan != 0 ||
4165 			  ext4_has_feature_journal_needs_recovery(sb));
4166 
4167 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4168 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4169 			goto failed_mount3a;
4170 
4171 	/*
4172 	 * The first inode we look at is the journal inode.  Don't try
4173 	 * root first: it may be modified in the journal!
4174 	 */
4175 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4176 		err = ext4_load_journal(sb, es, journal_devnum);
4177 		if (err)
4178 			goto failed_mount3a;
4179 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4180 		   ext4_has_feature_journal_needs_recovery(sb)) {
4181 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4182 		       "suppressed and not mounted read-only");
4183 		goto failed_mount_wq;
4184 	} else {
4185 		/* Nojournal mode, all journal mount options are illegal */
4186 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4187 			ext4_msg(sb, KERN_ERR, "can't mount with "
4188 				 "journal_checksum, fs mounted w/o journal");
4189 			goto failed_mount_wq;
4190 		}
4191 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4192 			ext4_msg(sb, KERN_ERR, "can't mount with "
4193 				 "journal_async_commit, fs mounted w/o journal");
4194 			goto failed_mount_wq;
4195 		}
4196 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4197 			ext4_msg(sb, KERN_ERR, "can't mount with "
4198 				 "commit=%lu, fs mounted w/o journal",
4199 				 sbi->s_commit_interval / HZ);
4200 			goto failed_mount_wq;
4201 		}
4202 		if (EXT4_MOUNT_DATA_FLAGS &
4203 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4204 			ext4_msg(sb, KERN_ERR, "can't mount with "
4205 				 "data=, fs mounted w/o journal");
4206 			goto failed_mount_wq;
4207 		}
4208 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4209 		clear_opt(sb, JOURNAL_CHECKSUM);
4210 		clear_opt(sb, DATA_FLAGS);
4211 		sbi->s_journal = NULL;
4212 		needs_recovery = 0;
4213 		goto no_journal;
4214 	}
4215 
4216 	if (ext4_has_feature_64bit(sb) &&
4217 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4218 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4219 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4220 		goto failed_mount_wq;
4221 	}
4222 
4223 	if (!set_journal_csum_feature_set(sb)) {
4224 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4225 			 "feature set");
4226 		goto failed_mount_wq;
4227 	}
4228 
4229 	/* We have now updated the journal if required, so we can
4230 	 * validate the data journaling mode. */
4231 	switch (test_opt(sb, DATA_FLAGS)) {
4232 	case 0:
4233 		/* No mode set, assume a default based on the journal
4234 		 * capabilities: ORDERED_DATA if the journal can
4235 		 * cope, else JOURNAL_DATA
4236 		 */
4237 		if (jbd2_journal_check_available_features
4238 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4239 			set_opt(sb, ORDERED_DATA);
4240 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4241 		} else {
4242 			set_opt(sb, JOURNAL_DATA);
4243 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4244 		}
4245 		break;
4246 
4247 	case EXT4_MOUNT_ORDERED_DATA:
4248 	case EXT4_MOUNT_WRITEBACK_DATA:
4249 		if (!jbd2_journal_check_available_features
4250 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4251 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4252 			       "requested data journaling mode");
4253 			goto failed_mount_wq;
4254 		}
4255 	default:
4256 		break;
4257 	}
4258 
4259 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4260 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4261 		ext4_msg(sb, KERN_ERR, "can't mount with "
4262 			"journal_async_commit in data=ordered mode");
4263 		goto failed_mount_wq;
4264 	}
4265 
4266 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4267 
4268 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4269 
4270 no_journal:
4271 	if (!test_opt(sb, NO_MBCACHE)) {
4272 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4273 		if (!sbi->s_ea_block_cache) {
4274 			ext4_msg(sb, KERN_ERR,
4275 				 "Failed to create ea_block_cache");
4276 			goto failed_mount_wq;
4277 		}
4278 
4279 		if (ext4_has_feature_ea_inode(sb)) {
4280 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4281 			if (!sbi->s_ea_inode_cache) {
4282 				ext4_msg(sb, KERN_ERR,
4283 					 "Failed to create ea_inode_cache");
4284 				goto failed_mount_wq;
4285 			}
4286 		}
4287 	}
4288 
4289 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4290 	    (blocksize != PAGE_SIZE)) {
4291 		ext4_msg(sb, KERN_ERR,
4292 			 "Unsupported blocksize for fs encryption");
4293 		goto failed_mount_wq;
4294 	}
4295 
4296 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4297 	    !ext4_has_feature_encrypt(sb)) {
4298 		ext4_set_feature_encrypt(sb);
4299 		ext4_commit_super(sb, 1);
4300 	}
4301 
4302 	/*
4303 	 * Get the # of file system overhead blocks from the
4304 	 * superblock if present.
4305 	 */
4306 	if (es->s_overhead_clusters)
4307 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4308 	else {
4309 		err = ext4_calculate_overhead(sb);
4310 		if (err)
4311 			goto failed_mount_wq;
4312 	}
4313 
4314 	/*
4315 	 * The maximum number of concurrent works can be high and
4316 	 * concurrency isn't really necessary.  Limit it to 1.
4317 	 */
4318 	EXT4_SB(sb)->rsv_conversion_wq =
4319 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4320 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4321 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4322 		ret = -ENOMEM;
4323 		goto failed_mount4;
4324 	}
4325 
4326 	/*
4327 	 * The jbd2_journal_load will have done any necessary log recovery,
4328 	 * so we can safely mount the rest of the filesystem now.
4329 	 */
4330 
4331 	root = ext4_iget(sb, EXT4_ROOT_INO);
4332 	if (IS_ERR(root)) {
4333 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4334 		ret = PTR_ERR(root);
4335 		root = NULL;
4336 		goto failed_mount4;
4337 	}
4338 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4339 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4340 		iput(root);
4341 		goto failed_mount4;
4342 	}
4343 	sb->s_root = d_make_root(root);
4344 	if (!sb->s_root) {
4345 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4346 		ret = -ENOMEM;
4347 		goto failed_mount4;
4348 	}
4349 
4350 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4351 	if (ret == -EROFS) {
4352 		sb->s_flags |= SB_RDONLY;
4353 		ret = 0;
4354 	} else if (ret)
4355 		goto failed_mount4a;
4356 
4357 	/* determine the minimum size of new large inodes, if present */
4358 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4359 	    sbi->s_want_extra_isize == 0) {
4360 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4361 						     EXT4_GOOD_OLD_INODE_SIZE;
4362 		if (ext4_has_feature_extra_isize(sb)) {
4363 			if (sbi->s_want_extra_isize <
4364 			    le16_to_cpu(es->s_want_extra_isize))
4365 				sbi->s_want_extra_isize =
4366 					le16_to_cpu(es->s_want_extra_isize);
4367 			if (sbi->s_want_extra_isize <
4368 			    le16_to_cpu(es->s_min_extra_isize))
4369 				sbi->s_want_extra_isize =
4370 					le16_to_cpu(es->s_min_extra_isize);
4371 		}
4372 	}
4373 	/* Check if enough inode space is available */
4374 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4375 							sbi->s_inode_size) {
4376 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4377 						       EXT4_GOOD_OLD_INODE_SIZE;
4378 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4379 			 "available");
4380 	}
4381 
4382 	ext4_set_resv_clusters(sb);
4383 
4384 	err = ext4_setup_system_zone(sb);
4385 	if (err) {
4386 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4387 			 "zone (%d)", err);
4388 		goto failed_mount4a;
4389 	}
4390 
4391 	ext4_ext_init(sb);
4392 	err = ext4_mb_init(sb);
4393 	if (err) {
4394 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4395 			 err);
4396 		goto failed_mount5;
4397 	}
4398 
4399 	block = ext4_count_free_clusters(sb);
4400 	ext4_free_blocks_count_set(sbi->s_es,
4401 				   EXT4_C2B(sbi, block));
4402 	ext4_superblock_csum_set(sb);
4403 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4404 				  GFP_KERNEL);
4405 	if (!err) {
4406 		unsigned long freei = ext4_count_free_inodes(sb);
4407 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4408 		ext4_superblock_csum_set(sb);
4409 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4410 					  GFP_KERNEL);
4411 	}
4412 	if (!err)
4413 		err = percpu_counter_init(&sbi->s_dirs_counter,
4414 					  ext4_count_dirs(sb), GFP_KERNEL);
4415 	if (!err)
4416 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4417 					  GFP_KERNEL);
4418 	if (!err)
4419 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4420 
4421 	if (err) {
4422 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4423 		goto failed_mount6;
4424 	}
4425 
4426 	if (ext4_has_feature_flex_bg(sb))
4427 		if (!ext4_fill_flex_info(sb)) {
4428 			ext4_msg(sb, KERN_ERR,
4429 			       "unable to initialize "
4430 			       "flex_bg meta info!");
4431 			goto failed_mount6;
4432 		}
4433 
4434 	err = ext4_register_li_request(sb, first_not_zeroed);
4435 	if (err)
4436 		goto failed_mount6;
4437 
4438 	err = ext4_register_sysfs(sb);
4439 	if (err)
4440 		goto failed_mount7;
4441 
4442 #ifdef CONFIG_QUOTA
4443 	/* Enable quota usage during mount. */
4444 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4445 		err = ext4_enable_quotas(sb);
4446 		if (err)
4447 			goto failed_mount8;
4448 	}
4449 #endif  /* CONFIG_QUOTA */
4450 
4451 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4452 	ext4_orphan_cleanup(sb, es);
4453 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4454 	if (needs_recovery) {
4455 		ext4_msg(sb, KERN_INFO, "recovery complete");
4456 		ext4_mark_recovery_complete(sb, es);
4457 	}
4458 	if (EXT4_SB(sb)->s_journal) {
4459 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4460 			descr = " journalled data mode";
4461 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4462 			descr = " ordered data mode";
4463 		else
4464 			descr = " writeback data mode";
4465 	} else
4466 		descr = "out journal";
4467 
4468 	if (test_opt(sb, DISCARD)) {
4469 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4470 		if (!blk_queue_discard(q))
4471 			ext4_msg(sb, KERN_WARNING,
4472 				 "mounting with \"discard\" option, but "
4473 				 "the device does not support discard");
4474 	}
4475 
4476 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4477 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4478 			 "Opts: %.*s%s%s", descr,
4479 			 (int) sizeof(sbi->s_es->s_mount_opts),
4480 			 sbi->s_es->s_mount_opts,
4481 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4482 
4483 	if (es->s_error_count)
4484 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4485 
4486 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4487 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4488 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4489 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4490 
4491 	kfree(orig_data);
4492 	return 0;
4493 
4494 cantfind_ext4:
4495 	if (!silent)
4496 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4497 	goto failed_mount;
4498 
4499 #ifdef CONFIG_QUOTA
4500 failed_mount8:
4501 	ext4_unregister_sysfs(sb);
4502 #endif
4503 failed_mount7:
4504 	ext4_unregister_li_request(sb);
4505 failed_mount6:
4506 	ext4_mb_release(sb);
4507 	if (sbi->s_flex_groups)
4508 		kvfree(sbi->s_flex_groups);
4509 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4510 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4511 	percpu_counter_destroy(&sbi->s_dirs_counter);
4512 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4513 failed_mount5:
4514 	ext4_ext_release(sb);
4515 	ext4_release_system_zone(sb);
4516 failed_mount4a:
4517 	dput(sb->s_root);
4518 	sb->s_root = NULL;
4519 failed_mount4:
4520 	ext4_msg(sb, KERN_ERR, "mount failed");
4521 	if (EXT4_SB(sb)->rsv_conversion_wq)
4522 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4523 failed_mount_wq:
4524 	if (sbi->s_ea_inode_cache) {
4525 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4526 		sbi->s_ea_inode_cache = NULL;
4527 	}
4528 	if (sbi->s_ea_block_cache) {
4529 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4530 		sbi->s_ea_block_cache = NULL;
4531 	}
4532 	if (sbi->s_journal) {
4533 		jbd2_journal_destroy(sbi->s_journal);
4534 		sbi->s_journal = NULL;
4535 	}
4536 failed_mount3a:
4537 	ext4_es_unregister_shrinker(sbi);
4538 failed_mount3:
4539 	del_timer_sync(&sbi->s_err_report);
4540 	if (sbi->s_mmp_tsk)
4541 		kthread_stop(sbi->s_mmp_tsk);
4542 failed_mount2:
4543 	for (i = 0; i < db_count; i++)
4544 		brelse(sbi->s_group_desc[i]);
4545 	kvfree(sbi->s_group_desc);
4546 failed_mount:
4547 	if (sbi->s_chksum_driver)
4548 		crypto_free_shash(sbi->s_chksum_driver);
4549 #ifdef CONFIG_QUOTA
4550 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4551 		kfree(sbi->s_qf_names[i]);
4552 #endif
4553 	ext4_blkdev_remove(sbi);
4554 	brelse(bh);
4555 out_fail:
4556 	sb->s_fs_info = NULL;
4557 	kfree(sbi->s_blockgroup_lock);
4558 out_free_base:
4559 	kfree(sbi);
4560 	kfree(orig_data);
4561 	fs_put_dax(dax_dev);
4562 	return err ? err : ret;
4563 }
4564 
4565 /*
4566  * Setup any per-fs journal parameters now.  We'll do this both on
4567  * initial mount, once the journal has been initialised but before we've
4568  * done any recovery; and again on any subsequent remount.
4569  */
4570 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4571 {
4572 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4573 
4574 	journal->j_commit_interval = sbi->s_commit_interval;
4575 	journal->j_min_batch_time = sbi->s_min_batch_time;
4576 	journal->j_max_batch_time = sbi->s_max_batch_time;
4577 
4578 	write_lock(&journal->j_state_lock);
4579 	if (test_opt(sb, BARRIER))
4580 		journal->j_flags |= JBD2_BARRIER;
4581 	else
4582 		journal->j_flags &= ~JBD2_BARRIER;
4583 	if (test_opt(sb, DATA_ERR_ABORT))
4584 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4585 	else
4586 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4587 	write_unlock(&journal->j_state_lock);
4588 }
4589 
4590 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4591 					     unsigned int journal_inum)
4592 {
4593 	struct inode *journal_inode;
4594 
4595 	/*
4596 	 * Test for the existence of a valid inode on disk.  Bad things
4597 	 * happen if we iget() an unused inode, as the subsequent iput()
4598 	 * will try to delete it.
4599 	 */
4600 	journal_inode = ext4_iget(sb, journal_inum);
4601 	if (IS_ERR(journal_inode)) {
4602 		ext4_msg(sb, KERN_ERR, "no journal found");
4603 		return NULL;
4604 	}
4605 	if (!journal_inode->i_nlink) {
4606 		make_bad_inode(journal_inode);
4607 		iput(journal_inode);
4608 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4609 		return NULL;
4610 	}
4611 
4612 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4613 		  journal_inode, journal_inode->i_size);
4614 	if (!S_ISREG(journal_inode->i_mode)) {
4615 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4616 		iput(journal_inode);
4617 		return NULL;
4618 	}
4619 	return journal_inode;
4620 }
4621 
4622 static journal_t *ext4_get_journal(struct super_block *sb,
4623 				   unsigned int journal_inum)
4624 {
4625 	struct inode *journal_inode;
4626 	journal_t *journal;
4627 
4628 	BUG_ON(!ext4_has_feature_journal(sb));
4629 
4630 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4631 	if (!journal_inode)
4632 		return NULL;
4633 
4634 	journal = jbd2_journal_init_inode(journal_inode);
4635 	if (!journal) {
4636 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4637 		iput(journal_inode);
4638 		return NULL;
4639 	}
4640 	journal->j_private = sb;
4641 	ext4_init_journal_params(sb, journal);
4642 	return journal;
4643 }
4644 
4645 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4646 				       dev_t j_dev)
4647 {
4648 	struct buffer_head *bh;
4649 	journal_t *journal;
4650 	ext4_fsblk_t start;
4651 	ext4_fsblk_t len;
4652 	int hblock, blocksize;
4653 	ext4_fsblk_t sb_block;
4654 	unsigned long offset;
4655 	struct ext4_super_block *es;
4656 	struct block_device *bdev;
4657 
4658 	BUG_ON(!ext4_has_feature_journal(sb));
4659 
4660 	bdev = ext4_blkdev_get(j_dev, sb);
4661 	if (bdev == NULL)
4662 		return NULL;
4663 
4664 	blocksize = sb->s_blocksize;
4665 	hblock = bdev_logical_block_size(bdev);
4666 	if (blocksize < hblock) {
4667 		ext4_msg(sb, KERN_ERR,
4668 			"blocksize too small for journal device");
4669 		goto out_bdev;
4670 	}
4671 
4672 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4673 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4674 	set_blocksize(bdev, blocksize);
4675 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4676 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4677 		       "external journal");
4678 		goto out_bdev;
4679 	}
4680 
4681 	es = (struct ext4_super_block *) (bh->b_data + offset);
4682 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4683 	    !(le32_to_cpu(es->s_feature_incompat) &
4684 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4685 		ext4_msg(sb, KERN_ERR, "external journal has "
4686 					"bad superblock");
4687 		brelse(bh);
4688 		goto out_bdev;
4689 	}
4690 
4691 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4692 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4693 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4694 		ext4_msg(sb, KERN_ERR, "external journal has "
4695 				       "corrupt superblock");
4696 		brelse(bh);
4697 		goto out_bdev;
4698 	}
4699 
4700 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4701 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4702 		brelse(bh);
4703 		goto out_bdev;
4704 	}
4705 
4706 	len = ext4_blocks_count(es);
4707 	start = sb_block + 1;
4708 	brelse(bh);	/* we're done with the superblock */
4709 
4710 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4711 					start, len, blocksize);
4712 	if (!journal) {
4713 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4714 		goto out_bdev;
4715 	}
4716 	journal->j_private = sb;
4717 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4718 	wait_on_buffer(journal->j_sb_buffer);
4719 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4720 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4721 		goto out_journal;
4722 	}
4723 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4724 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4725 					"user (unsupported) - %d",
4726 			be32_to_cpu(journal->j_superblock->s_nr_users));
4727 		goto out_journal;
4728 	}
4729 	EXT4_SB(sb)->journal_bdev = bdev;
4730 	ext4_init_journal_params(sb, journal);
4731 	return journal;
4732 
4733 out_journal:
4734 	jbd2_journal_destroy(journal);
4735 out_bdev:
4736 	ext4_blkdev_put(bdev);
4737 	return NULL;
4738 }
4739 
4740 static int ext4_load_journal(struct super_block *sb,
4741 			     struct ext4_super_block *es,
4742 			     unsigned long journal_devnum)
4743 {
4744 	journal_t *journal;
4745 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4746 	dev_t journal_dev;
4747 	int err = 0;
4748 	int really_read_only;
4749 
4750 	BUG_ON(!ext4_has_feature_journal(sb));
4751 
4752 	if (journal_devnum &&
4753 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4754 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4755 			"numbers have changed");
4756 		journal_dev = new_decode_dev(journal_devnum);
4757 	} else
4758 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4759 
4760 	really_read_only = bdev_read_only(sb->s_bdev);
4761 
4762 	/*
4763 	 * Are we loading a blank journal or performing recovery after a
4764 	 * crash?  For recovery, we need to check in advance whether we
4765 	 * can get read-write access to the device.
4766 	 */
4767 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4768 		if (sb_rdonly(sb)) {
4769 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4770 					"required on readonly filesystem");
4771 			if (really_read_only) {
4772 				ext4_msg(sb, KERN_ERR, "write access "
4773 					"unavailable, cannot proceed "
4774 					"(try mounting with noload)");
4775 				return -EROFS;
4776 			}
4777 			ext4_msg(sb, KERN_INFO, "write access will "
4778 			       "be enabled during recovery");
4779 		}
4780 	}
4781 
4782 	if (journal_inum && journal_dev) {
4783 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4784 		       "and inode journals!");
4785 		return -EINVAL;
4786 	}
4787 
4788 	if (journal_inum) {
4789 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4790 			return -EINVAL;
4791 	} else {
4792 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4793 			return -EINVAL;
4794 	}
4795 
4796 	if (!(journal->j_flags & JBD2_BARRIER))
4797 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4798 
4799 	if (!ext4_has_feature_journal_needs_recovery(sb))
4800 		err = jbd2_journal_wipe(journal, !really_read_only);
4801 	if (!err) {
4802 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4803 		if (save)
4804 			memcpy(save, ((char *) es) +
4805 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4806 		err = jbd2_journal_load(journal);
4807 		if (save)
4808 			memcpy(((char *) es) + EXT4_S_ERR_START,
4809 			       save, EXT4_S_ERR_LEN);
4810 		kfree(save);
4811 	}
4812 
4813 	if (err) {
4814 		ext4_msg(sb, KERN_ERR, "error loading journal");
4815 		jbd2_journal_destroy(journal);
4816 		return err;
4817 	}
4818 
4819 	EXT4_SB(sb)->s_journal = journal;
4820 	ext4_clear_journal_err(sb, es);
4821 
4822 	if (!really_read_only && journal_devnum &&
4823 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4824 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4825 
4826 		/* Make sure we flush the recovery flag to disk. */
4827 		ext4_commit_super(sb, 1);
4828 	}
4829 
4830 	return 0;
4831 }
4832 
4833 static int ext4_commit_super(struct super_block *sb, int sync)
4834 {
4835 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4836 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4837 	int error = 0;
4838 
4839 	if (!sbh || block_device_ejected(sb))
4840 		return error;
4841 
4842 	/*
4843 	 * The superblock bh should be mapped, but it might not be if the
4844 	 * device was hot-removed. Not much we can do but fail the I/O.
4845 	 */
4846 	if (!buffer_mapped(sbh))
4847 		return error;
4848 
4849 	/*
4850 	 * If the file system is mounted read-only, don't update the
4851 	 * superblock write time.  This avoids updating the superblock
4852 	 * write time when we are mounting the root file system
4853 	 * read/only but we need to replay the journal; at that point,
4854 	 * for people who are east of GMT and who make their clock
4855 	 * tick in localtime for Windows bug-for-bug compatibility,
4856 	 * the clock is set in the future, and this will cause e2fsck
4857 	 * to complain and force a full file system check.
4858 	 */
4859 	if (!(sb->s_flags & SB_RDONLY))
4860 		ext4_update_tstamp(es, s_wtime);
4861 	if (sb->s_bdev->bd_part)
4862 		es->s_kbytes_written =
4863 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4864 			    ((part_stat_read(sb->s_bdev->bd_part,
4865 					     sectors[STAT_WRITE]) -
4866 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4867 	else
4868 		es->s_kbytes_written =
4869 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4870 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4871 		ext4_free_blocks_count_set(es,
4872 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4873 				&EXT4_SB(sb)->s_freeclusters_counter)));
4874 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4875 		es->s_free_inodes_count =
4876 			cpu_to_le32(percpu_counter_sum_positive(
4877 				&EXT4_SB(sb)->s_freeinodes_counter));
4878 	BUFFER_TRACE(sbh, "marking dirty");
4879 	ext4_superblock_csum_set(sb);
4880 	if (sync)
4881 		lock_buffer(sbh);
4882 	if (buffer_write_io_error(sbh)) {
4883 		/*
4884 		 * Oh, dear.  A previous attempt to write the
4885 		 * superblock failed.  This could happen because the
4886 		 * USB device was yanked out.  Or it could happen to
4887 		 * be a transient write error and maybe the block will
4888 		 * be remapped.  Nothing we can do but to retry the
4889 		 * write and hope for the best.
4890 		 */
4891 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4892 		       "superblock detected");
4893 		clear_buffer_write_io_error(sbh);
4894 		set_buffer_uptodate(sbh);
4895 	}
4896 	mark_buffer_dirty(sbh);
4897 	if (sync) {
4898 		unlock_buffer(sbh);
4899 		error = __sync_dirty_buffer(sbh,
4900 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4901 		if (buffer_write_io_error(sbh)) {
4902 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4903 			       "superblock");
4904 			clear_buffer_write_io_error(sbh);
4905 			set_buffer_uptodate(sbh);
4906 		}
4907 	}
4908 	return error;
4909 }
4910 
4911 /*
4912  * Have we just finished recovery?  If so, and if we are mounting (or
4913  * remounting) the filesystem readonly, then we will end up with a
4914  * consistent fs on disk.  Record that fact.
4915  */
4916 static void ext4_mark_recovery_complete(struct super_block *sb,
4917 					struct ext4_super_block *es)
4918 {
4919 	journal_t *journal = EXT4_SB(sb)->s_journal;
4920 
4921 	if (!ext4_has_feature_journal(sb)) {
4922 		BUG_ON(journal != NULL);
4923 		return;
4924 	}
4925 	jbd2_journal_lock_updates(journal);
4926 	if (jbd2_journal_flush(journal) < 0)
4927 		goto out;
4928 
4929 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
4930 		ext4_clear_feature_journal_needs_recovery(sb);
4931 		ext4_commit_super(sb, 1);
4932 	}
4933 
4934 out:
4935 	jbd2_journal_unlock_updates(journal);
4936 }
4937 
4938 /*
4939  * If we are mounting (or read-write remounting) a filesystem whose journal
4940  * has recorded an error from a previous lifetime, move that error to the
4941  * main filesystem now.
4942  */
4943 static void ext4_clear_journal_err(struct super_block *sb,
4944 				   struct ext4_super_block *es)
4945 {
4946 	journal_t *journal;
4947 	int j_errno;
4948 	const char *errstr;
4949 
4950 	BUG_ON(!ext4_has_feature_journal(sb));
4951 
4952 	journal = EXT4_SB(sb)->s_journal;
4953 
4954 	/*
4955 	 * Now check for any error status which may have been recorded in the
4956 	 * journal by a prior ext4_error() or ext4_abort()
4957 	 */
4958 
4959 	j_errno = jbd2_journal_errno(journal);
4960 	if (j_errno) {
4961 		char nbuf[16];
4962 
4963 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4964 		ext4_warning(sb, "Filesystem error recorded "
4965 			     "from previous mount: %s", errstr);
4966 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4967 
4968 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4969 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4970 		ext4_commit_super(sb, 1);
4971 
4972 		jbd2_journal_clear_err(journal);
4973 		jbd2_journal_update_sb_errno(journal);
4974 	}
4975 }
4976 
4977 /*
4978  * Force the running and committing transactions to commit,
4979  * and wait on the commit.
4980  */
4981 int ext4_force_commit(struct super_block *sb)
4982 {
4983 	journal_t *journal;
4984 
4985 	if (sb_rdonly(sb))
4986 		return 0;
4987 
4988 	journal = EXT4_SB(sb)->s_journal;
4989 	return ext4_journal_force_commit(journal);
4990 }
4991 
4992 static int ext4_sync_fs(struct super_block *sb, int wait)
4993 {
4994 	int ret = 0;
4995 	tid_t target;
4996 	bool needs_barrier = false;
4997 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4998 
4999 	if (unlikely(ext4_forced_shutdown(sbi)))
5000 		return 0;
5001 
5002 	trace_ext4_sync_fs(sb, wait);
5003 	flush_workqueue(sbi->rsv_conversion_wq);
5004 	/*
5005 	 * Writeback quota in non-journalled quota case - journalled quota has
5006 	 * no dirty dquots
5007 	 */
5008 	dquot_writeback_dquots(sb, -1);
5009 	/*
5010 	 * Data writeback is possible w/o journal transaction, so barrier must
5011 	 * being sent at the end of the function. But we can skip it if
5012 	 * transaction_commit will do it for us.
5013 	 */
5014 	if (sbi->s_journal) {
5015 		target = jbd2_get_latest_transaction(sbi->s_journal);
5016 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5017 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5018 			needs_barrier = true;
5019 
5020 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5021 			if (wait)
5022 				ret = jbd2_log_wait_commit(sbi->s_journal,
5023 							   target);
5024 		}
5025 	} else if (wait && test_opt(sb, BARRIER))
5026 		needs_barrier = true;
5027 	if (needs_barrier) {
5028 		int err;
5029 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5030 		if (!ret)
5031 			ret = err;
5032 	}
5033 
5034 	return ret;
5035 }
5036 
5037 /*
5038  * LVM calls this function before a (read-only) snapshot is created.  This
5039  * gives us a chance to flush the journal completely and mark the fs clean.
5040  *
5041  * Note that only this function cannot bring a filesystem to be in a clean
5042  * state independently. It relies on upper layer to stop all data & metadata
5043  * modifications.
5044  */
5045 static int ext4_freeze(struct super_block *sb)
5046 {
5047 	int error = 0;
5048 	journal_t *journal;
5049 
5050 	if (sb_rdonly(sb))
5051 		return 0;
5052 
5053 	journal = EXT4_SB(sb)->s_journal;
5054 
5055 	if (journal) {
5056 		/* Now we set up the journal barrier. */
5057 		jbd2_journal_lock_updates(journal);
5058 
5059 		/*
5060 		 * Don't clear the needs_recovery flag if we failed to
5061 		 * flush the journal.
5062 		 */
5063 		error = jbd2_journal_flush(journal);
5064 		if (error < 0)
5065 			goto out;
5066 
5067 		/* Journal blocked and flushed, clear needs_recovery flag. */
5068 		ext4_clear_feature_journal_needs_recovery(sb);
5069 	}
5070 
5071 	error = ext4_commit_super(sb, 1);
5072 out:
5073 	if (journal)
5074 		/* we rely on upper layer to stop further updates */
5075 		jbd2_journal_unlock_updates(journal);
5076 	return error;
5077 }
5078 
5079 /*
5080  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5081  * flag here, even though the filesystem is not technically dirty yet.
5082  */
5083 static int ext4_unfreeze(struct super_block *sb)
5084 {
5085 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5086 		return 0;
5087 
5088 	if (EXT4_SB(sb)->s_journal) {
5089 		/* Reset the needs_recovery flag before the fs is unlocked. */
5090 		ext4_set_feature_journal_needs_recovery(sb);
5091 	}
5092 
5093 	ext4_commit_super(sb, 1);
5094 	return 0;
5095 }
5096 
5097 /*
5098  * Structure to save mount options for ext4_remount's benefit
5099  */
5100 struct ext4_mount_options {
5101 	unsigned long s_mount_opt;
5102 	unsigned long s_mount_opt2;
5103 	kuid_t s_resuid;
5104 	kgid_t s_resgid;
5105 	unsigned long s_commit_interval;
5106 	u32 s_min_batch_time, s_max_batch_time;
5107 #ifdef CONFIG_QUOTA
5108 	int s_jquota_fmt;
5109 	char *s_qf_names[EXT4_MAXQUOTAS];
5110 #endif
5111 };
5112 
5113 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5114 {
5115 	struct ext4_super_block *es;
5116 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5117 	unsigned long old_sb_flags;
5118 	struct ext4_mount_options old_opts;
5119 	int enable_quota = 0;
5120 	ext4_group_t g;
5121 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5122 	int err = 0;
5123 #ifdef CONFIG_QUOTA
5124 	int i, j;
5125 	char *to_free[EXT4_MAXQUOTAS];
5126 #endif
5127 	char *orig_data = kstrdup(data, GFP_KERNEL);
5128 
5129 	if (data && !orig_data)
5130 		return -ENOMEM;
5131 
5132 	/* Store the original options */
5133 	old_sb_flags = sb->s_flags;
5134 	old_opts.s_mount_opt = sbi->s_mount_opt;
5135 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5136 	old_opts.s_resuid = sbi->s_resuid;
5137 	old_opts.s_resgid = sbi->s_resgid;
5138 	old_opts.s_commit_interval = sbi->s_commit_interval;
5139 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5140 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5141 #ifdef CONFIG_QUOTA
5142 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5143 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5144 		if (sbi->s_qf_names[i]) {
5145 			char *qf_name = get_qf_name(sb, sbi, i);
5146 
5147 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5148 			if (!old_opts.s_qf_names[i]) {
5149 				for (j = 0; j < i; j++)
5150 					kfree(old_opts.s_qf_names[j]);
5151 				kfree(orig_data);
5152 				return -ENOMEM;
5153 			}
5154 		} else
5155 			old_opts.s_qf_names[i] = NULL;
5156 #endif
5157 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5158 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5159 
5160 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5161 		err = -EINVAL;
5162 		goto restore_opts;
5163 	}
5164 
5165 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5166 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5167 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5168 			 "during remount not supported; ignoring");
5169 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5170 	}
5171 
5172 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5173 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5174 			ext4_msg(sb, KERN_ERR, "can't mount with "
5175 				 "both data=journal and delalloc");
5176 			err = -EINVAL;
5177 			goto restore_opts;
5178 		}
5179 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5180 			ext4_msg(sb, KERN_ERR, "can't mount with "
5181 				 "both data=journal and dioread_nolock");
5182 			err = -EINVAL;
5183 			goto restore_opts;
5184 		}
5185 		if (test_opt(sb, DAX)) {
5186 			ext4_msg(sb, KERN_ERR, "can't mount with "
5187 				 "both data=journal and dax");
5188 			err = -EINVAL;
5189 			goto restore_opts;
5190 		}
5191 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5192 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5193 			ext4_msg(sb, KERN_ERR, "can't mount with "
5194 				"journal_async_commit in data=ordered mode");
5195 			err = -EINVAL;
5196 			goto restore_opts;
5197 		}
5198 	}
5199 
5200 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5201 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5202 		err = -EINVAL;
5203 		goto restore_opts;
5204 	}
5205 
5206 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5207 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5208 			"dax flag with busy inodes while remounting");
5209 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5210 	}
5211 
5212 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5213 		ext4_abort(sb, "Abort forced by user");
5214 
5215 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5216 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5217 
5218 	es = sbi->s_es;
5219 
5220 	if (sbi->s_journal) {
5221 		ext4_init_journal_params(sb, sbi->s_journal);
5222 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5223 	}
5224 
5225 	if (*flags & SB_LAZYTIME)
5226 		sb->s_flags |= SB_LAZYTIME;
5227 
5228 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5229 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5230 			err = -EROFS;
5231 			goto restore_opts;
5232 		}
5233 
5234 		if (*flags & SB_RDONLY) {
5235 			err = sync_filesystem(sb);
5236 			if (err < 0)
5237 				goto restore_opts;
5238 			err = dquot_suspend(sb, -1);
5239 			if (err < 0)
5240 				goto restore_opts;
5241 
5242 			/*
5243 			 * First of all, the unconditional stuff we have to do
5244 			 * to disable replay of the journal when we next remount
5245 			 */
5246 			sb->s_flags |= SB_RDONLY;
5247 
5248 			/*
5249 			 * OK, test if we are remounting a valid rw partition
5250 			 * readonly, and if so set the rdonly flag and then
5251 			 * mark the partition as valid again.
5252 			 */
5253 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5254 			    (sbi->s_mount_state & EXT4_VALID_FS))
5255 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5256 
5257 			if (sbi->s_journal)
5258 				ext4_mark_recovery_complete(sb, es);
5259 			if (sbi->s_mmp_tsk)
5260 				kthread_stop(sbi->s_mmp_tsk);
5261 		} else {
5262 			/* Make sure we can mount this feature set readwrite */
5263 			if (ext4_has_feature_readonly(sb) ||
5264 			    !ext4_feature_set_ok(sb, 0)) {
5265 				err = -EROFS;
5266 				goto restore_opts;
5267 			}
5268 			/*
5269 			 * Make sure the group descriptor checksums
5270 			 * are sane.  If they aren't, refuse to remount r/w.
5271 			 */
5272 			for (g = 0; g < sbi->s_groups_count; g++) {
5273 				struct ext4_group_desc *gdp =
5274 					ext4_get_group_desc(sb, g, NULL);
5275 
5276 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5277 					ext4_msg(sb, KERN_ERR,
5278 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5279 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5280 					       le16_to_cpu(gdp->bg_checksum));
5281 					err = -EFSBADCRC;
5282 					goto restore_opts;
5283 				}
5284 			}
5285 
5286 			/*
5287 			 * If we have an unprocessed orphan list hanging
5288 			 * around from a previously readonly bdev mount,
5289 			 * require a full umount/remount for now.
5290 			 */
5291 			if (es->s_last_orphan) {
5292 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5293 				       "remount RDWR because of unprocessed "
5294 				       "orphan inode list.  Please "
5295 				       "umount/remount instead");
5296 				err = -EINVAL;
5297 				goto restore_opts;
5298 			}
5299 
5300 			/*
5301 			 * Mounting a RDONLY partition read-write, so reread
5302 			 * and store the current valid flag.  (It may have
5303 			 * been changed by e2fsck since we originally mounted
5304 			 * the partition.)
5305 			 */
5306 			if (sbi->s_journal)
5307 				ext4_clear_journal_err(sb, es);
5308 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5309 
5310 			err = ext4_setup_super(sb, es, 0);
5311 			if (err)
5312 				goto restore_opts;
5313 
5314 			sb->s_flags &= ~SB_RDONLY;
5315 			if (ext4_has_feature_mmp(sb))
5316 				if (ext4_multi_mount_protect(sb,
5317 						le64_to_cpu(es->s_mmp_block))) {
5318 					err = -EROFS;
5319 					goto restore_opts;
5320 				}
5321 			enable_quota = 1;
5322 		}
5323 	}
5324 
5325 	/*
5326 	 * Reinitialize lazy itable initialization thread based on
5327 	 * current settings
5328 	 */
5329 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5330 		ext4_unregister_li_request(sb);
5331 	else {
5332 		ext4_group_t first_not_zeroed;
5333 		first_not_zeroed = ext4_has_uninit_itable(sb);
5334 		ext4_register_li_request(sb, first_not_zeroed);
5335 	}
5336 
5337 	ext4_setup_system_zone(sb);
5338 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5339 		err = ext4_commit_super(sb, 1);
5340 		if (err)
5341 			goto restore_opts;
5342 	}
5343 
5344 #ifdef CONFIG_QUOTA
5345 	/* Release old quota file names */
5346 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5347 		kfree(old_opts.s_qf_names[i]);
5348 	if (enable_quota) {
5349 		if (sb_any_quota_suspended(sb))
5350 			dquot_resume(sb, -1);
5351 		else if (ext4_has_feature_quota(sb)) {
5352 			err = ext4_enable_quotas(sb);
5353 			if (err)
5354 				goto restore_opts;
5355 		}
5356 	}
5357 #endif
5358 
5359 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5360 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5361 	kfree(orig_data);
5362 	return 0;
5363 
5364 restore_opts:
5365 	sb->s_flags = old_sb_flags;
5366 	sbi->s_mount_opt = old_opts.s_mount_opt;
5367 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5368 	sbi->s_resuid = old_opts.s_resuid;
5369 	sbi->s_resgid = old_opts.s_resgid;
5370 	sbi->s_commit_interval = old_opts.s_commit_interval;
5371 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5372 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5373 #ifdef CONFIG_QUOTA
5374 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5375 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5376 		to_free[i] = get_qf_name(sb, sbi, i);
5377 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5378 	}
5379 	synchronize_rcu();
5380 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5381 		kfree(to_free[i]);
5382 #endif
5383 	kfree(orig_data);
5384 	return err;
5385 }
5386 
5387 #ifdef CONFIG_QUOTA
5388 static int ext4_statfs_project(struct super_block *sb,
5389 			       kprojid_t projid, struct kstatfs *buf)
5390 {
5391 	struct kqid qid;
5392 	struct dquot *dquot;
5393 	u64 limit;
5394 	u64 curblock;
5395 
5396 	qid = make_kqid_projid(projid);
5397 	dquot = dqget(sb, qid);
5398 	if (IS_ERR(dquot))
5399 		return PTR_ERR(dquot);
5400 	spin_lock(&dquot->dq_dqb_lock);
5401 
5402 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5403 		 dquot->dq_dqb.dqb_bsoftlimit :
5404 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5405 	if (limit && buf->f_blocks > limit) {
5406 		curblock = (dquot->dq_dqb.dqb_curspace +
5407 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5408 		buf->f_blocks = limit;
5409 		buf->f_bfree = buf->f_bavail =
5410 			(buf->f_blocks > curblock) ?
5411 			 (buf->f_blocks - curblock) : 0;
5412 	}
5413 
5414 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5415 		dquot->dq_dqb.dqb_isoftlimit :
5416 		dquot->dq_dqb.dqb_ihardlimit;
5417 	if (limit && buf->f_files > limit) {
5418 		buf->f_files = limit;
5419 		buf->f_ffree =
5420 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5421 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5422 	}
5423 
5424 	spin_unlock(&dquot->dq_dqb_lock);
5425 	dqput(dquot);
5426 	return 0;
5427 }
5428 #endif
5429 
5430 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5431 {
5432 	struct super_block *sb = dentry->d_sb;
5433 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5434 	struct ext4_super_block *es = sbi->s_es;
5435 	ext4_fsblk_t overhead = 0, resv_blocks;
5436 	u64 fsid;
5437 	s64 bfree;
5438 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5439 
5440 	if (!test_opt(sb, MINIX_DF))
5441 		overhead = sbi->s_overhead;
5442 
5443 	buf->f_type = EXT4_SUPER_MAGIC;
5444 	buf->f_bsize = sb->s_blocksize;
5445 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5446 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5447 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5448 	/* prevent underflow in case that few free space is available */
5449 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5450 	buf->f_bavail = buf->f_bfree -
5451 			(ext4_r_blocks_count(es) + resv_blocks);
5452 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5453 		buf->f_bavail = 0;
5454 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5455 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5456 	buf->f_namelen = EXT4_NAME_LEN;
5457 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5458 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5459 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5460 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5461 
5462 #ifdef CONFIG_QUOTA
5463 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5464 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5465 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5466 #endif
5467 	return 0;
5468 }
5469 
5470 
5471 #ifdef CONFIG_QUOTA
5472 
5473 /*
5474  * Helper functions so that transaction is started before we acquire dqio_sem
5475  * to keep correct lock ordering of transaction > dqio_sem
5476  */
5477 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5478 {
5479 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5480 }
5481 
5482 static int ext4_write_dquot(struct dquot *dquot)
5483 {
5484 	int ret, err;
5485 	handle_t *handle;
5486 	struct inode *inode;
5487 
5488 	inode = dquot_to_inode(dquot);
5489 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5490 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5491 	if (IS_ERR(handle))
5492 		return PTR_ERR(handle);
5493 	ret = dquot_commit(dquot);
5494 	err = ext4_journal_stop(handle);
5495 	if (!ret)
5496 		ret = err;
5497 	return ret;
5498 }
5499 
5500 static int ext4_acquire_dquot(struct dquot *dquot)
5501 {
5502 	int ret, err;
5503 	handle_t *handle;
5504 
5505 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5506 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5507 	if (IS_ERR(handle))
5508 		return PTR_ERR(handle);
5509 	ret = dquot_acquire(dquot);
5510 	err = ext4_journal_stop(handle);
5511 	if (!ret)
5512 		ret = err;
5513 	return ret;
5514 }
5515 
5516 static int ext4_release_dquot(struct dquot *dquot)
5517 {
5518 	int ret, err;
5519 	handle_t *handle;
5520 
5521 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5522 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5523 	if (IS_ERR(handle)) {
5524 		/* Release dquot anyway to avoid endless cycle in dqput() */
5525 		dquot_release(dquot);
5526 		return PTR_ERR(handle);
5527 	}
5528 	ret = dquot_release(dquot);
5529 	err = ext4_journal_stop(handle);
5530 	if (!ret)
5531 		ret = err;
5532 	return ret;
5533 }
5534 
5535 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5536 {
5537 	struct super_block *sb = dquot->dq_sb;
5538 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5539 
5540 	/* Are we journaling quotas? */
5541 	if (ext4_has_feature_quota(sb) ||
5542 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5543 		dquot_mark_dquot_dirty(dquot);
5544 		return ext4_write_dquot(dquot);
5545 	} else {
5546 		return dquot_mark_dquot_dirty(dquot);
5547 	}
5548 }
5549 
5550 static int ext4_write_info(struct super_block *sb, int type)
5551 {
5552 	int ret, err;
5553 	handle_t *handle;
5554 
5555 	/* Data block + inode block */
5556 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5557 	if (IS_ERR(handle))
5558 		return PTR_ERR(handle);
5559 	ret = dquot_commit_info(sb, type);
5560 	err = ext4_journal_stop(handle);
5561 	if (!ret)
5562 		ret = err;
5563 	return ret;
5564 }
5565 
5566 /*
5567  * Turn on quotas during mount time - we need to find
5568  * the quota file and such...
5569  */
5570 static int ext4_quota_on_mount(struct super_block *sb, int type)
5571 {
5572 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5573 					EXT4_SB(sb)->s_jquota_fmt, type);
5574 }
5575 
5576 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5577 {
5578 	struct ext4_inode_info *ei = EXT4_I(inode);
5579 
5580 	/* The first argument of lockdep_set_subclass has to be
5581 	 * *exactly* the same as the argument to init_rwsem() --- in
5582 	 * this case, in init_once() --- or lockdep gets unhappy
5583 	 * because the name of the lock is set using the
5584 	 * stringification of the argument to init_rwsem().
5585 	 */
5586 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5587 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5588 }
5589 
5590 /*
5591  * Standard function to be called on quota_on
5592  */
5593 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5594 			 const struct path *path)
5595 {
5596 	int err;
5597 
5598 	if (!test_opt(sb, QUOTA))
5599 		return -EINVAL;
5600 
5601 	/* Quotafile not on the same filesystem? */
5602 	if (path->dentry->d_sb != sb)
5603 		return -EXDEV;
5604 	/* Journaling quota? */
5605 	if (EXT4_SB(sb)->s_qf_names[type]) {
5606 		/* Quotafile not in fs root? */
5607 		if (path->dentry->d_parent != sb->s_root)
5608 			ext4_msg(sb, KERN_WARNING,
5609 				"Quota file not on filesystem root. "
5610 				"Journaled quota will not work");
5611 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5612 	} else {
5613 		/*
5614 		 * Clear the flag just in case mount options changed since
5615 		 * last time.
5616 		 */
5617 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5618 	}
5619 
5620 	/*
5621 	 * When we journal data on quota file, we have to flush journal to see
5622 	 * all updates to the file when we bypass pagecache...
5623 	 */
5624 	if (EXT4_SB(sb)->s_journal &&
5625 	    ext4_should_journal_data(d_inode(path->dentry))) {
5626 		/*
5627 		 * We don't need to lock updates but journal_flush() could
5628 		 * otherwise be livelocked...
5629 		 */
5630 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5631 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5632 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5633 		if (err)
5634 			return err;
5635 	}
5636 
5637 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5638 	err = dquot_quota_on(sb, type, format_id, path);
5639 	if (err) {
5640 		lockdep_set_quota_inode(path->dentry->d_inode,
5641 					     I_DATA_SEM_NORMAL);
5642 	} else {
5643 		struct inode *inode = d_inode(path->dentry);
5644 		handle_t *handle;
5645 
5646 		/*
5647 		 * Set inode flags to prevent userspace from messing with quota
5648 		 * files. If this fails, we return success anyway since quotas
5649 		 * are already enabled and this is not a hard failure.
5650 		 */
5651 		inode_lock(inode);
5652 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5653 		if (IS_ERR(handle))
5654 			goto unlock_inode;
5655 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5656 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5657 				S_NOATIME | S_IMMUTABLE);
5658 		ext4_mark_inode_dirty(handle, inode);
5659 		ext4_journal_stop(handle);
5660 	unlock_inode:
5661 		inode_unlock(inode);
5662 	}
5663 	return err;
5664 }
5665 
5666 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5667 			     unsigned int flags)
5668 {
5669 	int err;
5670 	struct inode *qf_inode;
5671 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5672 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5673 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5674 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5675 	};
5676 
5677 	BUG_ON(!ext4_has_feature_quota(sb));
5678 
5679 	if (!qf_inums[type])
5680 		return -EPERM;
5681 
5682 	qf_inode = ext4_iget(sb, qf_inums[type]);
5683 	if (IS_ERR(qf_inode)) {
5684 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5685 		return PTR_ERR(qf_inode);
5686 	}
5687 
5688 	/* Don't account quota for quota files to avoid recursion */
5689 	qf_inode->i_flags |= S_NOQUOTA;
5690 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5691 	err = dquot_enable(qf_inode, type, format_id, flags);
5692 	iput(qf_inode);
5693 	if (err)
5694 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5695 
5696 	return err;
5697 }
5698 
5699 /* Enable usage tracking for all quota types. */
5700 static int ext4_enable_quotas(struct super_block *sb)
5701 {
5702 	int type, err = 0;
5703 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5704 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5705 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5706 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5707 	};
5708 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5709 		test_opt(sb, USRQUOTA),
5710 		test_opt(sb, GRPQUOTA),
5711 		test_opt(sb, PRJQUOTA),
5712 	};
5713 
5714 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5715 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5716 		if (qf_inums[type]) {
5717 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5718 				DQUOT_USAGE_ENABLED |
5719 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5720 			if (err) {
5721 				ext4_warning(sb,
5722 					"Failed to enable quota tracking "
5723 					"(type=%d, err=%d). Please run "
5724 					"e2fsck to fix.", type, err);
5725 				for (type--; type >= 0; type--)
5726 					dquot_quota_off(sb, type);
5727 
5728 				return err;
5729 			}
5730 		}
5731 	}
5732 	return 0;
5733 }
5734 
5735 static int ext4_quota_off(struct super_block *sb, int type)
5736 {
5737 	struct inode *inode = sb_dqopt(sb)->files[type];
5738 	handle_t *handle;
5739 	int err;
5740 
5741 	/* Force all delayed allocation blocks to be allocated.
5742 	 * Caller already holds s_umount sem */
5743 	if (test_opt(sb, DELALLOC))
5744 		sync_filesystem(sb);
5745 
5746 	if (!inode || !igrab(inode))
5747 		goto out;
5748 
5749 	err = dquot_quota_off(sb, type);
5750 	if (err || ext4_has_feature_quota(sb))
5751 		goto out_put;
5752 
5753 	inode_lock(inode);
5754 	/*
5755 	 * Update modification times of quota files when userspace can
5756 	 * start looking at them. If we fail, we return success anyway since
5757 	 * this is not a hard failure and quotas are already disabled.
5758 	 */
5759 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5760 	if (IS_ERR(handle))
5761 		goto out_unlock;
5762 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5763 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5764 	inode->i_mtime = inode->i_ctime = current_time(inode);
5765 	ext4_mark_inode_dirty(handle, inode);
5766 	ext4_journal_stop(handle);
5767 out_unlock:
5768 	inode_unlock(inode);
5769 out_put:
5770 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5771 	iput(inode);
5772 	return err;
5773 out:
5774 	return dquot_quota_off(sb, type);
5775 }
5776 
5777 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5778  * acquiring the locks... As quota files are never truncated and quota code
5779  * itself serializes the operations (and no one else should touch the files)
5780  * we don't have to be afraid of races */
5781 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5782 			       size_t len, loff_t off)
5783 {
5784 	struct inode *inode = sb_dqopt(sb)->files[type];
5785 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5786 	int offset = off & (sb->s_blocksize - 1);
5787 	int tocopy;
5788 	size_t toread;
5789 	struct buffer_head *bh;
5790 	loff_t i_size = i_size_read(inode);
5791 
5792 	if (off > i_size)
5793 		return 0;
5794 	if (off+len > i_size)
5795 		len = i_size-off;
5796 	toread = len;
5797 	while (toread > 0) {
5798 		tocopy = sb->s_blocksize - offset < toread ?
5799 				sb->s_blocksize - offset : toread;
5800 		bh = ext4_bread(NULL, inode, blk, 0);
5801 		if (IS_ERR(bh))
5802 			return PTR_ERR(bh);
5803 		if (!bh)	/* A hole? */
5804 			memset(data, 0, tocopy);
5805 		else
5806 			memcpy(data, bh->b_data+offset, tocopy);
5807 		brelse(bh);
5808 		offset = 0;
5809 		toread -= tocopy;
5810 		data += tocopy;
5811 		blk++;
5812 	}
5813 	return len;
5814 }
5815 
5816 /* Write to quotafile (we know the transaction is already started and has
5817  * enough credits) */
5818 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5819 				const char *data, size_t len, loff_t off)
5820 {
5821 	struct inode *inode = sb_dqopt(sb)->files[type];
5822 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5823 	int err, offset = off & (sb->s_blocksize - 1);
5824 	int retries = 0;
5825 	struct buffer_head *bh;
5826 	handle_t *handle = journal_current_handle();
5827 
5828 	if (EXT4_SB(sb)->s_journal && !handle) {
5829 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5830 			" cancelled because transaction is not started",
5831 			(unsigned long long)off, (unsigned long long)len);
5832 		return -EIO;
5833 	}
5834 	/*
5835 	 * Since we account only one data block in transaction credits,
5836 	 * then it is impossible to cross a block boundary.
5837 	 */
5838 	if (sb->s_blocksize - offset < len) {
5839 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5840 			" cancelled because not block aligned",
5841 			(unsigned long long)off, (unsigned long long)len);
5842 		return -EIO;
5843 	}
5844 
5845 	do {
5846 		bh = ext4_bread(handle, inode, blk,
5847 				EXT4_GET_BLOCKS_CREATE |
5848 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5849 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5850 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5851 	if (IS_ERR(bh))
5852 		return PTR_ERR(bh);
5853 	if (!bh)
5854 		goto out;
5855 	BUFFER_TRACE(bh, "get write access");
5856 	err = ext4_journal_get_write_access(handle, bh);
5857 	if (err) {
5858 		brelse(bh);
5859 		return err;
5860 	}
5861 	lock_buffer(bh);
5862 	memcpy(bh->b_data+offset, data, len);
5863 	flush_dcache_page(bh->b_page);
5864 	unlock_buffer(bh);
5865 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5866 	brelse(bh);
5867 out:
5868 	if (inode->i_size < off + len) {
5869 		i_size_write(inode, off + len);
5870 		EXT4_I(inode)->i_disksize = inode->i_size;
5871 		ext4_mark_inode_dirty(handle, inode);
5872 	}
5873 	return len;
5874 }
5875 
5876 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5877 {
5878 	const struct quota_format_ops	*ops;
5879 
5880 	if (!sb_has_quota_loaded(sb, qid->type))
5881 		return -ESRCH;
5882 	ops = sb_dqopt(sb)->ops[qid->type];
5883 	if (!ops || !ops->get_next_id)
5884 		return -ENOSYS;
5885 	return dquot_get_next_id(sb, qid);
5886 }
5887 #endif
5888 
5889 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5890 		       const char *dev_name, void *data)
5891 {
5892 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5893 }
5894 
5895 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5896 static inline void register_as_ext2(void)
5897 {
5898 	int err = register_filesystem(&ext2_fs_type);
5899 	if (err)
5900 		printk(KERN_WARNING
5901 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5902 }
5903 
5904 static inline void unregister_as_ext2(void)
5905 {
5906 	unregister_filesystem(&ext2_fs_type);
5907 }
5908 
5909 static inline int ext2_feature_set_ok(struct super_block *sb)
5910 {
5911 	if (ext4_has_unknown_ext2_incompat_features(sb))
5912 		return 0;
5913 	if (sb_rdonly(sb))
5914 		return 1;
5915 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5916 		return 0;
5917 	return 1;
5918 }
5919 #else
5920 static inline void register_as_ext2(void) { }
5921 static inline void unregister_as_ext2(void) { }
5922 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5923 #endif
5924 
5925 static inline void register_as_ext3(void)
5926 {
5927 	int err = register_filesystem(&ext3_fs_type);
5928 	if (err)
5929 		printk(KERN_WARNING
5930 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5931 }
5932 
5933 static inline void unregister_as_ext3(void)
5934 {
5935 	unregister_filesystem(&ext3_fs_type);
5936 }
5937 
5938 static inline int ext3_feature_set_ok(struct super_block *sb)
5939 {
5940 	if (ext4_has_unknown_ext3_incompat_features(sb))
5941 		return 0;
5942 	if (!ext4_has_feature_journal(sb))
5943 		return 0;
5944 	if (sb_rdonly(sb))
5945 		return 1;
5946 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5947 		return 0;
5948 	return 1;
5949 }
5950 
5951 static struct file_system_type ext4_fs_type = {
5952 	.owner		= THIS_MODULE,
5953 	.name		= "ext4",
5954 	.mount		= ext4_mount,
5955 	.kill_sb	= kill_block_super,
5956 	.fs_flags	= FS_REQUIRES_DEV,
5957 };
5958 MODULE_ALIAS_FS("ext4");
5959 
5960 /* Shared across all ext4 file systems */
5961 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5962 
5963 static int __init ext4_init_fs(void)
5964 {
5965 	int i, err;
5966 
5967 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5968 	ext4_li_info = NULL;
5969 	mutex_init(&ext4_li_mtx);
5970 
5971 	/* Build-time check for flags consistency */
5972 	ext4_check_flag_values();
5973 
5974 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5975 		init_waitqueue_head(&ext4__ioend_wq[i]);
5976 
5977 	err = ext4_init_es();
5978 	if (err)
5979 		return err;
5980 
5981 	err = ext4_init_pending();
5982 	if (err)
5983 		goto out6;
5984 
5985 	err = ext4_init_pageio();
5986 	if (err)
5987 		goto out5;
5988 
5989 	err = ext4_init_system_zone();
5990 	if (err)
5991 		goto out4;
5992 
5993 	err = ext4_init_sysfs();
5994 	if (err)
5995 		goto out3;
5996 
5997 	err = ext4_init_mballoc();
5998 	if (err)
5999 		goto out2;
6000 	err = init_inodecache();
6001 	if (err)
6002 		goto out1;
6003 	register_as_ext3();
6004 	register_as_ext2();
6005 	err = register_filesystem(&ext4_fs_type);
6006 	if (err)
6007 		goto out;
6008 
6009 	return 0;
6010 out:
6011 	unregister_as_ext2();
6012 	unregister_as_ext3();
6013 	destroy_inodecache();
6014 out1:
6015 	ext4_exit_mballoc();
6016 out2:
6017 	ext4_exit_sysfs();
6018 out3:
6019 	ext4_exit_system_zone();
6020 out4:
6021 	ext4_exit_pageio();
6022 out5:
6023 	ext4_exit_pending();
6024 out6:
6025 	ext4_exit_es();
6026 
6027 	return err;
6028 }
6029 
6030 static void __exit ext4_exit_fs(void)
6031 {
6032 	ext4_destroy_lazyinit_thread();
6033 	unregister_as_ext2();
6034 	unregister_as_ext3();
6035 	unregister_filesystem(&ext4_fs_type);
6036 	destroy_inodecache();
6037 	ext4_exit_mballoc();
6038 	ext4_exit_sysfs();
6039 	ext4_exit_system_zone();
6040 	ext4_exit_pageio();
6041 	ext4_exit_es();
6042 	ext4_exit_pending();
6043 }
6044 
6045 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6046 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6047 MODULE_LICENSE("GPL");
6048 MODULE_SOFTDEP("pre: crc32c");
6049 module_init(ext4_init_fs)
6050 module_exit(ext4_exit_fs)
6051