xref: /linux/fs/ext4/super.c (revision b68fc09be48edbc47de1a0f3d42ef8adf6c0ac55)
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 #else
918 static inline void ext4_quota_off_umount(struct super_block *sb)
919 {
920 }
921 #endif
922 
923 static void ext4_put_super(struct super_block *sb)
924 {
925 	struct ext4_sb_info *sbi = EXT4_SB(sb);
926 	struct ext4_super_block *es = sbi->s_es;
927 	int aborted = 0;
928 	int i, err;
929 
930 	ext4_unregister_li_request(sb);
931 	ext4_quota_off_umount(sb);
932 
933 	destroy_workqueue(sbi->rsv_conversion_wq);
934 
935 	if (sbi->s_journal) {
936 		aborted = is_journal_aborted(sbi->s_journal);
937 		err = jbd2_journal_destroy(sbi->s_journal);
938 		sbi->s_journal = NULL;
939 		if ((err < 0) && !aborted)
940 			ext4_abort(sb, "Couldn't clean up the journal");
941 	}
942 
943 	ext4_unregister_sysfs(sb);
944 	ext4_es_unregister_shrinker(sbi);
945 	del_timer_sync(&sbi->s_err_report);
946 	ext4_release_system_zone(sb);
947 	ext4_mb_release(sb);
948 	ext4_ext_release(sb);
949 
950 	if (!sb_rdonly(sb) && !aborted) {
951 		ext4_clear_feature_journal_needs_recovery(sb);
952 		es->s_state = cpu_to_le16(sbi->s_mount_state);
953 	}
954 	if (!sb_rdonly(sb))
955 		ext4_commit_super(sb, 1);
956 
957 	for (i = 0; i < sbi->s_gdb_count; i++)
958 		brelse(sbi->s_group_desc[i]);
959 	kvfree(sbi->s_group_desc);
960 	kvfree(sbi->s_flex_groups);
961 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
962 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
963 	percpu_counter_destroy(&sbi->s_dirs_counter);
964 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
965 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
966 #ifdef CONFIG_QUOTA
967 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
968 		kfree(sbi->s_qf_names[i]);
969 #endif
970 
971 	/* Debugging code just in case the in-memory inode orphan list
972 	 * isn't empty.  The on-disk one can be non-empty if we've
973 	 * detected an error and taken the fs readonly, but the
974 	 * in-memory list had better be clean by this point. */
975 	if (!list_empty(&sbi->s_orphan))
976 		dump_orphan_list(sb, sbi);
977 	J_ASSERT(list_empty(&sbi->s_orphan));
978 
979 	sync_blockdev(sb->s_bdev);
980 	invalidate_bdev(sb->s_bdev);
981 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
982 		/*
983 		 * Invalidate the journal device's buffers.  We don't want them
984 		 * floating about in memory - the physical journal device may
985 		 * hotswapped, and it breaks the `ro-after' testing code.
986 		 */
987 		sync_blockdev(sbi->journal_bdev);
988 		invalidate_bdev(sbi->journal_bdev);
989 		ext4_blkdev_remove(sbi);
990 	}
991 	if (sbi->s_ea_inode_cache) {
992 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
993 		sbi->s_ea_inode_cache = NULL;
994 	}
995 	if (sbi->s_ea_block_cache) {
996 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
997 		sbi->s_ea_block_cache = NULL;
998 	}
999 	if (sbi->s_mmp_tsk)
1000 		kthread_stop(sbi->s_mmp_tsk);
1001 	brelse(sbi->s_sbh);
1002 	sb->s_fs_info = NULL;
1003 	/*
1004 	 * Now that we are completely done shutting down the
1005 	 * superblock, we need to actually destroy the kobject.
1006 	 */
1007 	kobject_put(&sbi->s_kobj);
1008 	wait_for_completion(&sbi->s_kobj_unregister);
1009 	if (sbi->s_chksum_driver)
1010 		crypto_free_shash(sbi->s_chksum_driver);
1011 	kfree(sbi->s_blockgroup_lock);
1012 	fs_put_dax(sbi->s_daxdev);
1013 	kfree(sbi);
1014 }
1015 
1016 static struct kmem_cache *ext4_inode_cachep;
1017 
1018 /*
1019  * Called inside transaction, so use GFP_NOFS
1020  */
1021 static struct inode *ext4_alloc_inode(struct super_block *sb)
1022 {
1023 	struct ext4_inode_info *ei;
1024 
1025 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1026 	if (!ei)
1027 		return NULL;
1028 
1029 	inode_set_iversion(&ei->vfs_inode, 1);
1030 	spin_lock_init(&ei->i_raw_lock);
1031 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1032 	spin_lock_init(&ei->i_prealloc_lock);
1033 	ext4_es_init_tree(&ei->i_es_tree);
1034 	rwlock_init(&ei->i_es_lock);
1035 	INIT_LIST_HEAD(&ei->i_es_list);
1036 	ei->i_es_all_nr = 0;
1037 	ei->i_es_shk_nr = 0;
1038 	ei->i_es_shrink_lblk = 0;
1039 	ei->i_reserved_data_blocks = 0;
1040 	ei->i_da_metadata_calc_len = 0;
1041 	ei->i_da_metadata_calc_last_lblock = 0;
1042 	spin_lock_init(&(ei->i_block_reservation_lock));
1043 #ifdef CONFIG_QUOTA
1044 	ei->i_reserved_quota = 0;
1045 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1046 #endif
1047 	ei->jinode = NULL;
1048 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1049 	spin_lock_init(&ei->i_completed_io_lock);
1050 	ei->i_sync_tid = 0;
1051 	ei->i_datasync_tid = 0;
1052 	atomic_set(&ei->i_unwritten, 0);
1053 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1054 	return &ei->vfs_inode;
1055 }
1056 
1057 static int ext4_drop_inode(struct inode *inode)
1058 {
1059 	int drop = generic_drop_inode(inode);
1060 
1061 	trace_ext4_drop_inode(inode, drop);
1062 	return drop;
1063 }
1064 
1065 static void ext4_i_callback(struct rcu_head *head)
1066 {
1067 	struct inode *inode = container_of(head, struct inode, i_rcu);
1068 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1069 }
1070 
1071 static void ext4_destroy_inode(struct inode *inode)
1072 {
1073 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1074 		ext4_msg(inode->i_sb, KERN_ERR,
1075 			 "Inode %lu (%p): orphan list check failed!",
1076 			 inode->i_ino, EXT4_I(inode));
1077 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1078 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1079 				true);
1080 		dump_stack();
1081 	}
1082 	call_rcu(&inode->i_rcu, ext4_i_callback);
1083 }
1084 
1085 static void init_once(void *foo)
1086 {
1087 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1088 
1089 	INIT_LIST_HEAD(&ei->i_orphan);
1090 	init_rwsem(&ei->xattr_sem);
1091 	init_rwsem(&ei->i_data_sem);
1092 	init_rwsem(&ei->i_mmap_sem);
1093 	inode_init_once(&ei->vfs_inode);
1094 }
1095 
1096 static int __init init_inodecache(void)
1097 {
1098 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1099 				sizeof(struct ext4_inode_info), 0,
1100 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1101 					SLAB_ACCOUNT),
1102 				offsetof(struct ext4_inode_info, i_data),
1103 				sizeof_field(struct ext4_inode_info, i_data),
1104 				init_once);
1105 	if (ext4_inode_cachep == NULL)
1106 		return -ENOMEM;
1107 	return 0;
1108 }
1109 
1110 static void destroy_inodecache(void)
1111 {
1112 	/*
1113 	 * Make sure all delayed rcu free inodes are flushed before we
1114 	 * destroy cache.
1115 	 */
1116 	rcu_barrier();
1117 	kmem_cache_destroy(ext4_inode_cachep);
1118 }
1119 
1120 void ext4_clear_inode(struct inode *inode)
1121 {
1122 	invalidate_inode_buffers(inode);
1123 	clear_inode(inode);
1124 	dquot_drop(inode);
1125 	ext4_discard_preallocations(inode);
1126 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1127 	if (EXT4_I(inode)->jinode) {
1128 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1129 					       EXT4_I(inode)->jinode);
1130 		jbd2_free_inode(EXT4_I(inode)->jinode);
1131 		EXT4_I(inode)->jinode = NULL;
1132 	}
1133 	fscrypt_put_encryption_info(inode);
1134 }
1135 
1136 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1137 					u64 ino, u32 generation)
1138 {
1139 	struct inode *inode;
1140 
1141 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1142 		return ERR_PTR(-ESTALE);
1143 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1144 		return ERR_PTR(-ESTALE);
1145 
1146 	/* iget isn't really right if the inode is currently unallocated!!
1147 	 *
1148 	 * ext4_read_inode will return a bad_inode if the inode had been
1149 	 * deleted, so we should be safe.
1150 	 *
1151 	 * Currently we don't know the generation for parent directory, so
1152 	 * a generation of 0 means "accept any"
1153 	 */
1154 	inode = ext4_iget_normal(sb, ino);
1155 	if (IS_ERR(inode))
1156 		return ERR_CAST(inode);
1157 	if (generation && inode->i_generation != generation) {
1158 		iput(inode);
1159 		return ERR_PTR(-ESTALE);
1160 	}
1161 
1162 	return inode;
1163 }
1164 
1165 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1166 					int fh_len, int fh_type)
1167 {
1168 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1169 				    ext4_nfs_get_inode);
1170 }
1171 
1172 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1173 					int fh_len, int fh_type)
1174 {
1175 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1176 				    ext4_nfs_get_inode);
1177 }
1178 
1179 /*
1180  * Try to release metadata pages (indirect blocks, directories) which are
1181  * mapped via the block device.  Since these pages could have journal heads
1182  * which would prevent try_to_free_buffers() from freeing them, we must use
1183  * jbd2 layer's try_to_free_buffers() function to release them.
1184  */
1185 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1186 				 gfp_t wait)
1187 {
1188 	journal_t *journal = EXT4_SB(sb)->s_journal;
1189 
1190 	WARN_ON(PageChecked(page));
1191 	if (!page_has_buffers(page))
1192 		return 0;
1193 	if (journal)
1194 		return jbd2_journal_try_to_free_buffers(journal, page,
1195 						wait & ~__GFP_DIRECT_RECLAIM);
1196 	return try_to_free_buffers(page);
1197 }
1198 
1199 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1200 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1201 {
1202 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1203 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1204 }
1205 
1206 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1207 							void *fs_data)
1208 {
1209 	handle_t *handle = fs_data;
1210 	int res, res2, credits, retries = 0;
1211 
1212 	/*
1213 	 * Encrypting the root directory is not allowed because e2fsck expects
1214 	 * lost+found to exist and be unencrypted, and encrypting the root
1215 	 * directory would imply encrypting the lost+found directory as well as
1216 	 * the filename "lost+found" itself.
1217 	 */
1218 	if (inode->i_ino == EXT4_ROOT_INO)
1219 		return -EPERM;
1220 
1221 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1222 		return -EINVAL;
1223 
1224 	res = ext4_convert_inline_data(inode);
1225 	if (res)
1226 		return res;
1227 
1228 	/*
1229 	 * If a journal handle was specified, then the encryption context is
1230 	 * being set on a new inode via inheritance and is part of a larger
1231 	 * transaction to create the inode.  Otherwise the encryption context is
1232 	 * being set on an existing inode in its own transaction.  Only in the
1233 	 * latter case should the "retry on ENOSPC" logic be used.
1234 	 */
1235 
1236 	if (handle) {
1237 		res = ext4_xattr_set_handle(handle, inode,
1238 					    EXT4_XATTR_INDEX_ENCRYPTION,
1239 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1240 					    ctx, len, 0);
1241 		if (!res) {
1242 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1243 			ext4_clear_inode_state(inode,
1244 					EXT4_STATE_MAY_INLINE_DATA);
1245 			/*
1246 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1247 			 * S_DAX may be disabled
1248 			 */
1249 			ext4_set_inode_flags(inode);
1250 		}
1251 		return res;
1252 	}
1253 
1254 	res = dquot_initialize(inode);
1255 	if (res)
1256 		return res;
1257 retry:
1258 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1259 				     &credits);
1260 	if (res)
1261 		return res;
1262 
1263 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1264 	if (IS_ERR(handle))
1265 		return PTR_ERR(handle);
1266 
1267 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1268 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1269 				    ctx, len, 0);
1270 	if (!res) {
1271 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1272 		/*
1273 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1274 		 * S_DAX may be disabled
1275 		 */
1276 		ext4_set_inode_flags(inode);
1277 		res = ext4_mark_inode_dirty(handle, inode);
1278 		if (res)
1279 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1280 	}
1281 	res2 = ext4_journal_stop(handle);
1282 
1283 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1284 		goto retry;
1285 	if (!res)
1286 		res = res2;
1287 	return res;
1288 }
1289 
1290 static bool ext4_dummy_context(struct inode *inode)
1291 {
1292 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1293 }
1294 
1295 static const struct fscrypt_operations ext4_cryptops = {
1296 	.key_prefix		= "ext4:",
1297 	.get_context		= ext4_get_context,
1298 	.set_context		= ext4_set_context,
1299 	.dummy_context		= ext4_dummy_context,
1300 	.empty_dir		= ext4_empty_dir,
1301 	.max_namelen		= EXT4_NAME_LEN,
1302 };
1303 #endif
1304 
1305 #ifdef CONFIG_QUOTA
1306 static const char * const quotatypes[] = INITQFNAMES;
1307 #define QTYPE2NAME(t) (quotatypes[t])
1308 
1309 static int ext4_write_dquot(struct dquot *dquot);
1310 static int ext4_acquire_dquot(struct dquot *dquot);
1311 static int ext4_release_dquot(struct dquot *dquot);
1312 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1313 static int ext4_write_info(struct super_block *sb, int type);
1314 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1315 			 const struct path *path);
1316 static int ext4_quota_on_mount(struct super_block *sb, int type);
1317 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1318 			       size_t len, loff_t off);
1319 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1320 				const char *data, size_t len, loff_t off);
1321 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1322 			     unsigned int flags);
1323 static int ext4_enable_quotas(struct super_block *sb);
1324 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1325 
1326 static struct dquot **ext4_get_dquots(struct inode *inode)
1327 {
1328 	return EXT4_I(inode)->i_dquot;
1329 }
1330 
1331 static const struct dquot_operations ext4_quota_operations = {
1332 	.get_reserved_space	= ext4_get_reserved_space,
1333 	.write_dquot		= ext4_write_dquot,
1334 	.acquire_dquot		= ext4_acquire_dquot,
1335 	.release_dquot		= ext4_release_dquot,
1336 	.mark_dirty		= ext4_mark_dquot_dirty,
1337 	.write_info		= ext4_write_info,
1338 	.alloc_dquot		= dquot_alloc,
1339 	.destroy_dquot		= dquot_destroy,
1340 	.get_projid		= ext4_get_projid,
1341 	.get_inode_usage	= ext4_get_inode_usage,
1342 	.get_next_id		= ext4_get_next_id,
1343 };
1344 
1345 static const struct quotactl_ops ext4_qctl_operations = {
1346 	.quota_on	= ext4_quota_on,
1347 	.quota_off	= ext4_quota_off,
1348 	.quota_sync	= dquot_quota_sync,
1349 	.get_state	= dquot_get_state,
1350 	.set_info	= dquot_set_dqinfo,
1351 	.get_dqblk	= dquot_get_dqblk,
1352 	.set_dqblk	= dquot_set_dqblk,
1353 	.get_nextdqblk	= dquot_get_next_dqblk,
1354 };
1355 #endif
1356 
1357 static const struct super_operations ext4_sops = {
1358 	.alloc_inode	= ext4_alloc_inode,
1359 	.destroy_inode	= ext4_destroy_inode,
1360 	.write_inode	= ext4_write_inode,
1361 	.dirty_inode	= ext4_dirty_inode,
1362 	.drop_inode	= ext4_drop_inode,
1363 	.evict_inode	= ext4_evict_inode,
1364 	.put_super	= ext4_put_super,
1365 	.sync_fs	= ext4_sync_fs,
1366 	.freeze_fs	= ext4_freeze,
1367 	.unfreeze_fs	= ext4_unfreeze,
1368 	.statfs		= ext4_statfs,
1369 	.remount_fs	= ext4_remount,
1370 	.show_options	= ext4_show_options,
1371 #ifdef CONFIG_QUOTA
1372 	.quota_read	= ext4_quota_read,
1373 	.quota_write	= ext4_quota_write,
1374 	.get_dquots	= ext4_get_dquots,
1375 #endif
1376 	.bdev_try_to_free_page = bdev_try_to_free_page,
1377 };
1378 
1379 static const struct export_operations ext4_export_ops = {
1380 	.fh_to_dentry = ext4_fh_to_dentry,
1381 	.fh_to_parent = ext4_fh_to_parent,
1382 	.get_parent = ext4_get_parent,
1383 };
1384 
1385 enum {
1386 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1387 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1388 	Opt_nouid32, Opt_debug, Opt_removed,
1389 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1390 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1391 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1392 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1393 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1394 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1395 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1396 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1397 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1398 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1399 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1400 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1401 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1402 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1403 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1404 	Opt_dioread_nolock, Opt_dioread_lock,
1405 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1406 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1407 };
1408 
1409 static const match_table_t tokens = {
1410 	{Opt_bsd_df, "bsddf"},
1411 	{Opt_minix_df, "minixdf"},
1412 	{Opt_grpid, "grpid"},
1413 	{Opt_grpid, "bsdgroups"},
1414 	{Opt_nogrpid, "nogrpid"},
1415 	{Opt_nogrpid, "sysvgroups"},
1416 	{Opt_resgid, "resgid=%u"},
1417 	{Opt_resuid, "resuid=%u"},
1418 	{Opt_sb, "sb=%u"},
1419 	{Opt_err_cont, "errors=continue"},
1420 	{Opt_err_panic, "errors=panic"},
1421 	{Opt_err_ro, "errors=remount-ro"},
1422 	{Opt_nouid32, "nouid32"},
1423 	{Opt_debug, "debug"},
1424 	{Opt_removed, "oldalloc"},
1425 	{Opt_removed, "orlov"},
1426 	{Opt_user_xattr, "user_xattr"},
1427 	{Opt_nouser_xattr, "nouser_xattr"},
1428 	{Opt_acl, "acl"},
1429 	{Opt_noacl, "noacl"},
1430 	{Opt_noload, "norecovery"},
1431 	{Opt_noload, "noload"},
1432 	{Opt_removed, "nobh"},
1433 	{Opt_removed, "bh"},
1434 	{Opt_commit, "commit=%u"},
1435 	{Opt_min_batch_time, "min_batch_time=%u"},
1436 	{Opt_max_batch_time, "max_batch_time=%u"},
1437 	{Opt_journal_dev, "journal_dev=%u"},
1438 	{Opt_journal_path, "journal_path=%s"},
1439 	{Opt_journal_checksum, "journal_checksum"},
1440 	{Opt_nojournal_checksum, "nojournal_checksum"},
1441 	{Opt_journal_async_commit, "journal_async_commit"},
1442 	{Opt_abort, "abort"},
1443 	{Opt_data_journal, "data=journal"},
1444 	{Opt_data_ordered, "data=ordered"},
1445 	{Opt_data_writeback, "data=writeback"},
1446 	{Opt_data_err_abort, "data_err=abort"},
1447 	{Opt_data_err_ignore, "data_err=ignore"},
1448 	{Opt_offusrjquota, "usrjquota="},
1449 	{Opt_usrjquota, "usrjquota=%s"},
1450 	{Opt_offgrpjquota, "grpjquota="},
1451 	{Opt_grpjquota, "grpjquota=%s"},
1452 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1453 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1454 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1455 	{Opt_grpquota, "grpquota"},
1456 	{Opt_noquota, "noquota"},
1457 	{Opt_quota, "quota"},
1458 	{Opt_usrquota, "usrquota"},
1459 	{Opt_prjquota, "prjquota"},
1460 	{Opt_barrier, "barrier=%u"},
1461 	{Opt_barrier, "barrier"},
1462 	{Opt_nobarrier, "nobarrier"},
1463 	{Opt_i_version, "i_version"},
1464 	{Opt_dax, "dax"},
1465 	{Opt_stripe, "stripe=%u"},
1466 	{Opt_delalloc, "delalloc"},
1467 	{Opt_warn_on_error, "warn_on_error"},
1468 	{Opt_nowarn_on_error, "nowarn_on_error"},
1469 	{Opt_lazytime, "lazytime"},
1470 	{Opt_nolazytime, "nolazytime"},
1471 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1472 	{Opt_nodelalloc, "nodelalloc"},
1473 	{Opt_removed, "mblk_io_submit"},
1474 	{Opt_removed, "nomblk_io_submit"},
1475 	{Opt_block_validity, "block_validity"},
1476 	{Opt_noblock_validity, "noblock_validity"},
1477 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1478 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1479 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1480 	{Opt_auto_da_alloc, "auto_da_alloc"},
1481 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1482 	{Opt_dioread_nolock, "dioread_nolock"},
1483 	{Opt_dioread_lock, "dioread_lock"},
1484 	{Opt_discard, "discard"},
1485 	{Opt_nodiscard, "nodiscard"},
1486 	{Opt_init_itable, "init_itable=%u"},
1487 	{Opt_init_itable, "init_itable"},
1488 	{Opt_noinit_itable, "noinit_itable"},
1489 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1490 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1491 	{Opt_nombcache, "nombcache"},
1492 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1493 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1494 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1495 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1496 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1497 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1498 	{Opt_err, NULL},
1499 };
1500 
1501 static ext4_fsblk_t get_sb_block(void **data)
1502 {
1503 	ext4_fsblk_t	sb_block;
1504 	char		*options = (char *) *data;
1505 
1506 	if (!options || strncmp(options, "sb=", 3) != 0)
1507 		return 1;	/* Default location */
1508 
1509 	options += 3;
1510 	/* TODO: use simple_strtoll with >32bit ext4 */
1511 	sb_block = simple_strtoul(options, &options, 0);
1512 	if (*options && *options != ',') {
1513 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1514 		       (char *) *data);
1515 		return 1;
1516 	}
1517 	if (*options == ',')
1518 		options++;
1519 	*data = (void *) options;
1520 
1521 	return sb_block;
1522 }
1523 
1524 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1525 static const char deprecated_msg[] =
1526 	"Mount option \"%s\" will be removed by %s\n"
1527 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1528 
1529 #ifdef CONFIG_QUOTA
1530 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1531 {
1532 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1533 	char *qname;
1534 	int ret = -1;
1535 
1536 	if (sb_any_quota_loaded(sb) &&
1537 		!sbi->s_qf_names[qtype]) {
1538 		ext4_msg(sb, KERN_ERR,
1539 			"Cannot change journaled "
1540 			"quota options when quota turned on");
1541 		return -1;
1542 	}
1543 	if (ext4_has_feature_quota(sb)) {
1544 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1545 			 "ignored when QUOTA feature is enabled");
1546 		return 1;
1547 	}
1548 	qname = match_strdup(args);
1549 	if (!qname) {
1550 		ext4_msg(sb, KERN_ERR,
1551 			"Not enough memory for storing quotafile name");
1552 		return -1;
1553 	}
1554 	if (sbi->s_qf_names[qtype]) {
1555 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1556 			ret = 1;
1557 		else
1558 			ext4_msg(sb, KERN_ERR,
1559 				 "%s quota file already specified",
1560 				 QTYPE2NAME(qtype));
1561 		goto errout;
1562 	}
1563 	if (strchr(qname, '/')) {
1564 		ext4_msg(sb, KERN_ERR,
1565 			"quotafile must be on filesystem root");
1566 		goto errout;
1567 	}
1568 	sbi->s_qf_names[qtype] = qname;
1569 	set_opt(sb, QUOTA);
1570 	return 1;
1571 errout:
1572 	kfree(qname);
1573 	return ret;
1574 }
1575 
1576 static int clear_qf_name(struct super_block *sb, int qtype)
1577 {
1578 
1579 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1580 
1581 	if (sb_any_quota_loaded(sb) &&
1582 		sbi->s_qf_names[qtype]) {
1583 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1584 			" when quota turned on");
1585 		return -1;
1586 	}
1587 	kfree(sbi->s_qf_names[qtype]);
1588 	sbi->s_qf_names[qtype] = NULL;
1589 	return 1;
1590 }
1591 #endif
1592 
1593 #define MOPT_SET	0x0001
1594 #define MOPT_CLEAR	0x0002
1595 #define MOPT_NOSUPPORT	0x0004
1596 #define MOPT_EXPLICIT	0x0008
1597 #define MOPT_CLEAR_ERR	0x0010
1598 #define MOPT_GTE0	0x0020
1599 #ifdef CONFIG_QUOTA
1600 #define MOPT_Q		0
1601 #define MOPT_QFMT	0x0040
1602 #else
1603 #define MOPT_Q		MOPT_NOSUPPORT
1604 #define MOPT_QFMT	MOPT_NOSUPPORT
1605 #endif
1606 #define MOPT_DATAJ	0x0080
1607 #define MOPT_NO_EXT2	0x0100
1608 #define MOPT_NO_EXT3	0x0200
1609 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1610 #define MOPT_STRING	0x0400
1611 
1612 static const struct mount_opts {
1613 	int	token;
1614 	int	mount_opt;
1615 	int	flags;
1616 } ext4_mount_opts[] = {
1617 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1618 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1619 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1620 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1621 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1622 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1623 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1624 	 MOPT_EXT4_ONLY | MOPT_SET},
1625 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1626 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1627 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1628 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1629 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1630 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1631 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1632 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1633 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1634 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1635 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1636 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1637 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1638 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1639 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1640 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1641 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1642 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1643 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1644 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1645 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1646 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1647 	 MOPT_NO_EXT2},
1648 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1649 	 MOPT_NO_EXT2},
1650 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1651 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1652 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1653 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1654 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1655 	{Opt_commit, 0, MOPT_GTE0},
1656 	{Opt_max_batch_time, 0, MOPT_GTE0},
1657 	{Opt_min_batch_time, 0, MOPT_GTE0},
1658 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1659 	{Opt_init_itable, 0, MOPT_GTE0},
1660 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1661 	{Opt_stripe, 0, MOPT_GTE0},
1662 	{Opt_resuid, 0, MOPT_GTE0},
1663 	{Opt_resgid, 0, MOPT_GTE0},
1664 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1665 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1666 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1667 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1668 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1669 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1670 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1671 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1672 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1673 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1674 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1675 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1676 #else
1677 	{Opt_acl, 0, MOPT_NOSUPPORT},
1678 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1679 #endif
1680 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1681 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1682 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1683 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1684 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1685 							MOPT_SET | MOPT_Q},
1686 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1687 							MOPT_SET | MOPT_Q},
1688 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1689 							MOPT_SET | MOPT_Q},
1690 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1691 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1692 							MOPT_CLEAR | MOPT_Q},
1693 	{Opt_usrjquota, 0, MOPT_Q},
1694 	{Opt_grpjquota, 0, MOPT_Q},
1695 	{Opt_offusrjquota, 0, MOPT_Q},
1696 	{Opt_offgrpjquota, 0, MOPT_Q},
1697 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1698 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1699 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1700 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1701 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1702 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1703 	{Opt_err, 0, 0}
1704 };
1705 
1706 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1707 			    substring_t *args, unsigned long *journal_devnum,
1708 			    unsigned int *journal_ioprio, int is_remount)
1709 {
1710 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1711 	const struct mount_opts *m;
1712 	kuid_t uid;
1713 	kgid_t gid;
1714 	int arg = 0;
1715 
1716 #ifdef CONFIG_QUOTA
1717 	if (token == Opt_usrjquota)
1718 		return set_qf_name(sb, USRQUOTA, &args[0]);
1719 	else if (token == Opt_grpjquota)
1720 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1721 	else if (token == Opt_offusrjquota)
1722 		return clear_qf_name(sb, USRQUOTA);
1723 	else if (token == Opt_offgrpjquota)
1724 		return clear_qf_name(sb, GRPQUOTA);
1725 #endif
1726 	switch (token) {
1727 	case Opt_noacl:
1728 	case Opt_nouser_xattr:
1729 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1730 		break;
1731 	case Opt_sb:
1732 		return 1;	/* handled by get_sb_block() */
1733 	case Opt_removed:
1734 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1735 		return 1;
1736 	case Opt_abort:
1737 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1738 		return 1;
1739 	case Opt_i_version:
1740 		sb->s_flags |= SB_I_VERSION;
1741 		return 1;
1742 	case Opt_lazytime:
1743 		sb->s_flags |= SB_LAZYTIME;
1744 		return 1;
1745 	case Opt_nolazytime:
1746 		sb->s_flags &= ~SB_LAZYTIME;
1747 		return 1;
1748 	}
1749 
1750 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1751 		if (token == m->token)
1752 			break;
1753 
1754 	if (m->token == Opt_err) {
1755 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1756 			 "or missing value", opt);
1757 		return -1;
1758 	}
1759 
1760 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1761 		ext4_msg(sb, KERN_ERR,
1762 			 "Mount option \"%s\" incompatible with ext2", opt);
1763 		return -1;
1764 	}
1765 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1766 		ext4_msg(sb, KERN_ERR,
1767 			 "Mount option \"%s\" incompatible with ext3", opt);
1768 		return -1;
1769 	}
1770 
1771 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1772 		return -1;
1773 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1774 		return -1;
1775 	if (m->flags & MOPT_EXPLICIT) {
1776 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1777 			set_opt2(sb, EXPLICIT_DELALLOC);
1778 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1779 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1780 		} else
1781 			return -1;
1782 	}
1783 	if (m->flags & MOPT_CLEAR_ERR)
1784 		clear_opt(sb, ERRORS_MASK);
1785 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1786 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1787 			 "options when quota turned on");
1788 		return -1;
1789 	}
1790 
1791 	if (m->flags & MOPT_NOSUPPORT) {
1792 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1793 	} else if (token == Opt_commit) {
1794 		if (arg == 0)
1795 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1796 		sbi->s_commit_interval = HZ * arg;
1797 	} else if (token == Opt_debug_want_extra_isize) {
1798 		sbi->s_want_extra_isize = arg;
1799 	} else if (token == Opt_max_batch_time) {
1800 		sbi->s_max_batch_time = arg;
1801 	} else if (token == Opt_min_batch_time) {
1802 		sbi->s_min_batch_time = arg;
1803 	} else if (token == Opt_inode_readahead_blks) {
1804 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1805 			ext4_msg(sb, KERN_ERR,
1806 				 "EXT4-fs: inode_readahead_blks must be "
1807 				 "0 or a power of 2 smaller than 2^31");
1808 			return -1;
1809 		}
1810 		sbi->s_inode_readahead_blks = arg;
1811 	} else if (token == Opt_init_itable) {
1812 		set_opt(sb, INIT_INODE_TABLE);
1813 		if (!args->from)
1814 			arg = EXT4_DEF_LI_WAIT_MULT;
1815 		sbi->s_li_wait_mult = arg;
1816 	} else if (token == Opt_max_dir_size_kb) {
1817 		sbi->s_max_dir_size_kb = arg;
1818 	} else if (token == Opt_stripe) {
1819 		sbi->s_stripe = arg;
1820 	} else if (token == Opt_resuid) {
1821 		uid = make_kuid(current_user_ns(), arg);
1822 		if (!uid_valid(uid)) {
1823 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1824 			return -1;
1825 		}
1826 		sbi->s_resuid = uid;
1827 	} else if (token == Opt_resgid) {
1828 		gid = make_kgid(current_user_ns(), arg);
1829 		if (!gid_valid(gid)) {
1830 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1831 			return -1;
1832 		}
1833 		sbi->s_resgid = gid;
1834 	} else if (token == Opt_journal_dev) {
1835 		if (is_remount) {
1836 			ext4_msg(sb, KERN_ERR,
1837 				 "Cannot specify journal on remount");
1838 			return -1;
1839 		}
1840 		*journal_devnum = arg;
1841 	} else if (token == Opt_journal_path) {
1842 		char *journal_path;
1843 		struct inode *journal_inode;
1844 		struct path path;
1845 		int error;
1846 
1847 		if (is_remount) {
1848 			ext4_msg(sb, KERN_ERR,
1849 				 "Cannot specify journal on remount");
1850 			return -1;
1851 		}
1852 		journal_path = match_strdup(&args[0]);
1853 		if (!journal_path) {
1854 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1855 				"journal device string");
1856 			return -1;
1857 		}
1858 
1859 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1860 		if (error) {
1861 			ext4_msg(sb, KERN_ERR, "error: could not find "
1862 				"journal device path: error %d", error);
1863 			kfree(journal_path);
1864 			return -1;
1865 		}
1866 
1867 		journal_inode = d_inode(path.dentry);
1868 		if (!S_ISBLK(journal_inode->i_mode)) {
1869 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1870 				"is not a block device", journal_path);
1871 			path_put(&path);
1872 			kfree(journal_path);
1873 			return -1;
1874 		}
1875 
1876 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1877 		path_put(&path);
1878 		kfree(journal_path);
1879 	} else if (token == Opt_journal_ioprio) {
1880 		if (arg > 7) {
1881 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1882 				 " (must be 0-7)");
1883 			return -1;
1884 		}
1885 		*journal_ioprio =
1886 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1887 	} else if (token == Opt_test_dummy_encryption) {
1888 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1889 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1890 		ext4_msg(sb, KERN_WARNING,
1891 			 "Test dummy encryption mode enabled");
1892 #else
1893 		ext4_msg(sb, KERN_WARNING,
1894 			 "Test dummy encryption mount option ignored");
1895 #endif
1896 	} else if (m->flags & MOPT_DATAJ) {
1897 		if (is_remount) {
1898 			if (!sbi->s_journal)
1899 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1900 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1901 				ext4_msg(sb, KERN_ERR,
1902 					 "Cannot change data mode on remount");
1903 				return -1;
1904 			}
1905 		} else {
1906 			clear_opt(sb, DATA_FLAGS);
1907 			sbi->s_mount_opt |= m->mount_opt;
1908 		}
1909 #ifdef CONFIG_QUOTA
1910 	} else if (m->flags & MOPT_QFMT) {
1911 		if (sb_any_quota_loaded(sb) &&
1912 		    sbi->s_jquota_fmt != m->mount_opt) {
1913 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1914 				 "quota options when quota turned on");
1915 			return -1;
1916 		}
1917 		if (ext4_has_feature_quota(sb)) {
1918 			ext4_msg(sb, KERN_INFO,
1919 				 "Quota format mount options ignored "
1920 				 "when QUOTA feature is enabled");
1921 			return 1;
1922 		}
1923 		sbi->s_jquota_fmt = m->mount_opt;
1924 #endif
1925 	} else if (token == Opt_dax) {
1926 #ifdef CONFIG_FS_DAX
1927 		ext4_msg(sb, KERN_WARNING,
1928 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1929 			sbi->s_mount_opt |= m->mount_opt;
1930 #else
1931 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1932 		return -1;
1933 #endif
1934 	} else if (token == Opt_data_err_abort) {
1935 		sbi->s_mount_opt |= m->mount_opt;
1936 	} else if (token == Opt_data_err_ignore) {
1937 		sbi->s_mount_opt &= ~m->mount_opt;
1938 	} else {
1939 		if (!args->from)
1940 			arg = 1;
1941 		if (m->flags & MOPT_CLEAR)
1942 			arg = !arg;
1943 		else if (unlikely(!(m->flags & MOPT_SET))) {
1944 			ext4_msg(sb, KERN_WARNING,
1945 				 "buggy handling of option %s", opt);
1946 			WARN_ON(1);
1947 			return -1;
1948 		}
1949 		if (arg != 0)
1950 			sbi->s_mount_opt |= m->mount_opt;
1951 		else
1952 			sbi->s_mount_opt &= ~m->mount_opt;
1953 	}
1954 	return 1;
1955 }
1956 
1957 static int parse_options(char *options, struct super_block *sb,
1958 			 unsigned long *journal_devnum,
1959 			 unsigned int *journal_ioprio,
1960 			 int is_remount)
1961 {
1962 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1963 	char *p;
1964 	substring_t args[MAX_OPT_ARGS];
1965 	int token;
1966 
1967 	if (!options)
1968 		return 1;
1969 
1970 	while ((p = strsep(&options, ",")) != NULL) {
1971 		if (!*p)
1972 			continue;
1973 		/*
1974 		 * Initialize args struct so we know whether arg was
1975 		 * found; some options take optional arguments.
1976 		 */
1977 		args[0].to = args[0].from = NULL;
1978 		token = match_token(p, tokens, args);
1979 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1980 				     journal_ioprio, is_remount) < 0)
1981 			return 0;
1982 	}
1983 #ifdef CONFIG_QUOTA
1984 	/*
1985 	 * We do the test below only for project quotas. 'usrquota' and
1986 	 * 'grpquota' mount options are allowed even without quota feature
1987 	 * to support legacy quotas in quota files.
1988 	 */
1989 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1990 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1991 			 "Cannot enable project quota enforcement.");
1992 		return 0;
1993 	}
1994 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1995 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1996 			clear_opt(sb, USRQUOTA);
1997 
1998 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1999 			clear_opt(sb, GRPQUOTA);
2000 
2001 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2002 			ext4_msg(sb, KERN_ERR, "old and new quota "
2003 					"format mixing");
2004 			return 0;
2005 		}
2006 
2007 		if (!sbi->s_jquota_fmt) {
2008 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2009 					"not specified");
2010 			return 0;
2011 		}
2012 	}
2013 #endif
2014 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2015 		int blocksize =
2016 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2017 
2018 		if (blocksize < PAGE_SIZE) {
2019 			ext4_msg(sb, KERN_ERR, "can't mount with "
2020 				 "dioread_nolock if block size != PAGE_SIZE");
2021 			return 0;
2022 		}
2023 	}
2024 	return 1;
2025 }
2026 
2027 static inline void ext4_show_quota_options(struct seq_file *seq,
2028 					   struct super_block *sb)
2029 {
2030 #if defined(CONFIG_QUOTA)
2031 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2032 
2033 	if (sbi->s_jquota_fmt) {
2034 		char *fmtname = "";
2035 
2036 		switch (sbi->s_jquota_fmt) {
2037 		case QFMT_VFS_OLD:
2038 			fmtname = "vfsold";
2039 			break;
2040 		case QFMT_VFS_V0:
2041 			fmtname = "vfsv0";
2042 			break;
2043 		case QFMT_VFS_V1:
2044 			fmtname = "vfsv1";
2045 			break;
2046 		}
2047 		seq_printf(seq, ",jqfmt=%s", fmtname);
2048 	}
2049 
2050 	if (sbi->s_qf_names[USRQUOTA])
2051 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
2052 
2053 	if (sbi->s_qf_names[GRPQUOTA])
2054 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
2055 #endif
2056 }
2057 
2058 static const char *token2str(int token)
2059 {
2060 	const struct match_token *t;
2061 
2062 	for (t = tokens; t->token != Opt_err; t++)
2063 		if (t->token == token && !strchr(t->pattern, '='))
2064 			break;
2065 	return t->pattern;
2066 }
2067 
2068 /*
2069  * Show an option if
2070  *  - it's set to a non-default value OR
2071  *  - if the per-sb default is different from the global default
2072  */
2073 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2074 			      int nodefs)
2075 {
2076 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2077 	struct ext4_super_block *es = sbi->s_es;
2078 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2079 	const struct mount_opts *m;
2080 	char sep = nodefs ? '\n' : ',';
2081 
2082 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2083 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2084 
2085 	if (sbi->s_sb_block != 1)
2086 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2087 
2088 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2089 		int want_set = m->flags & MOPT_SET;
2090 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2091 		    (m->flags & MOPT_CLEAR_ERR))
2092 			continue;
2093 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2094 			continue; /* skip if same as the default */
2095 		if ((want_set &&
2096 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2097 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2098 			continue; /* select Opt_noFoo vs Opt_Foo */
2099 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2100 	}
2101 
2102 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2103 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2104 		SEQ_OPTS_PRINT("resuid=%u",
2105 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2106 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2107 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2108 		SEQ_OPTS_PRINT("resgid=%u",
2109 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2110 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2111 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2112 		SEQ_OPTS_PUTS("errors=remount-ro");
2113 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2114 		SEQ_OPTS_PUTS("errors=continue");
2115 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2116 		SEQ_OPTS_PUTS("errors=panic");
2117 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2118 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2119 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2120 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2121 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2122 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2123 	if (sb->s_flags & SB_I_VERSION)
2124 		SEQ_OPTS_PUTS("i_version");
2125 	if (nodefs || sbi->s_stripe)
2126 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2127 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2128 			(sbi->s_mount_opt ^ def_mount_opt)) {
2129 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2130 			SEQ_OPTS_PUTS("data=journal");
2131 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2132 			SEQ_OPTS_PUTS("data=ordered");
2133 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2134 			SEQ_OPTS_PUTS("data=writeback");
2135 	}
2136 	if (nodefs ||
2137 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2138 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2139 			       sbi->s_inode_readahead_blks);
2140 
2141 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2142 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2143 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2144 	if (nodefs || sbi->s_max_dir_size_kb)
2145 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2146 	if (test_opt(sb, DATA_ERR_ABORT))
2147 		SEQ_OPTS_PUTS("data_err=abort");
2148 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
2149 		SEQ_OPTS_PUTS("test_dummy_encryption");
2150 
2151 	ext4_show_quota_options(seq, sb);
2152 	return 0;
2153 }
2154 
2155 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2156 {
2157 	return _ext4_show_options(seq, root->d_sb, 0);
2158 }
2159 
2160 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2161 {
2162 	struct super_block *sb = seq->private;
2163 	int rc;
2164 
2165 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2166 	rc = _ext4_show_options(seq, sb, 1);
2167 	seq_puts(seq, "\n");
2168 	return rc;
2169 }
2170 
2171 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2172 			    int read_only)
2173 {
2174 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2175 	int err = 0;
2176 
2177 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2178 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2179 			 "forcing read-only mode");
2180 		err = -EROFS;
2181 	}
2182 	if (read_only)
2183 		goto done;
2184 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2185 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2186 			 "running e2fsck is recommended");
2187 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2188 		ext4_msg(sb, KERN_WARNING,
2189 			 "warning: mounting fs with errors, "
2190 			 "running e2fsck is recommended");
2191 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2192 		 le16_to_cpu(es->s_mnt_count) >=
2193 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2194 		ext4_msg(sb, KERN_WARNING,
2195 			 "warning: maximal mount count reached, "
2196 			 "running e2fsck is recommended");
2197 	else if (le32_to_cpu(es->s_checkinterval) &&
2198 		 (ext4_get_tstamp(es, s_lastcheck) +
2199 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2200 		ext4_msg(sb, KERN_WARNING,
2201 			 "warning: checktime reached, "
2202 			 "running e2fsck is recommended");
2203 	if (!sbi->s_journal)
2204 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2205 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2206 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2207 	le16_add_cpu(&es->s_mnt_count, 1);
2208 	ext4_update_tstamp(es, s_mtime);
2209 	ext4_update_dynamic_rev(sb);
2210 	if (sbi->s_journal)
2211 		ext4_set_feature_journal_needs_recovery(sb);
2212 
2213 	err = ext4_commit_super(sb, 1);
2214 done:
2215 	if (test_opt(sb, DEBUG))
2216 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2217 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2218 			sb->s_blocksize,
2219 			sbi->s_groups_count,
2220 			EXT4_BLOCKS_PER_GROUP(sb),
2221 			EXT4_INODES_PER_GROUP(sb),
2222 			sbi->s_mount_opt, sbi->s_mount_opt2);
2223 
2224 	cleancache_init_fs(sb);
2225 	return err;
2226 }
2227 
2228 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2229 {
2230 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2231 	struct flex_groups *new_groups;
2232 	int size;
2233 
2234 	if (!sbi->s_log_groups_per_flex)
2235 		return 0;
2236 
2237 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2238 	if (size <= sbi->s_flex_groups_allocated)
2239 		return 0;
2240 
2241 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2242 	new_groups = kvzalloc(size, GFP_KERNEL);
2243 	if (!new_groups) {
2244 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2245 			 size / (int) sizeof(struct flex_groups));
2246 		return -ENOMEM;
2247 	}
2248 
2249 	if (sbi->s_flex_groups) {
2250 		memcpy(new_groups, sbi->s_flex_groups,
2251 		       (sbi->s_flex_groups_allocated *
2252 			sizeof(struct flex_groups)));
2253 		kvfree(sbi->s_flex_groups);
2254 	}
2255 	sbi->s_flex_groups = new_groups;
2256 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2257 	return 0;
2258 }
2259 
2260 static int ext4_fill_flex_info(struct super_block *sb)
2261 {
2262 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2263 	struct ext4_group_desc *gdp = NULL;
2264 	ext4_group_t flex_group;
2265 	int i, err;
2266 
2267 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2268 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2269 		sbi->s_log_groups_per_flex = 0;
2270 		return 1;
2271 	}
2272 
2273 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2274 	if (err)
2275 		goto failed;
2276 
2277 	for (i = 0; i < sbi->s_groups_count; i++) {
2278 		gdp = ext4_get_group_desc(sb, i, NULL);
2279 
2280 		flex_group = ext4_flex_group(sbi, i);
2281 		atomic_add(ext4_free_inodes_count(sb, gdp),
2282 			   &sbi->s_flex_groups[flex_group].free_inodes);
2283 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2284 			     &sbi->s_flex_groups[flex_group].free_clusters);
2285 		atomic_add(ext4_used_dirs_count(sb, gdp),
2286 			   &sbi->s_flex_groups[flex_group].used_dirs);
2287 	}
2288 
2289 	return 1;
2290 failed:
2291 	return 0;
2292 }
2293 
2294 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2295 				   struct ext4_group_desc *gdp)
2296 {
2297 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2298 	__u16 crc = 0;
2299 	__le32 le_group = cpu_to_le32(block_group);
2300 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2301 
2302 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2303 		/* Use new metadata_csum algorithm */
2304 		__u32 csum32;
2305 		__u16 dummy_csum = 0;
2306 
2307 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2308 				     sizeof(le_group));
2309 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2310 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2311 				     sizeof(dummy_csum));
2312 		offset += sizeof(dummy_csum);
2313 		if (offset < sbi->s_desc_size)
2314 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2315 					     sbi->s_desc_size - offset);
2316 
2317 		crc = csum32 & 0xFFFF;
2318 		goto out;
2319 	}
2320 
2321 	/* old crc16 code */
2322 	if (!ext4_has_feature_gdt_csum(sb))
2323 		return 0;
2324 
2325 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2326 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2327 	crc = crc16(crc, (__u8 *)gdp, offset);
2328 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2329 	/* for checksum of struct ext4_group_desc do the rest...*/
2330 	if (ext4_has_feature_64bit(sb) &&
2331 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2332 		crc = crc16(crc, (__u8 *)gdp + offset,
2333 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2334 				offset);
2335 
2336 out:
2337 	return cpu_to_le16(crc);
2338 }
2339 
2340 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2341 				struct ext4_group_desc *gdp)
2342 {
2343 	if (ext4_has_group_desc_csum(sb) &&
2344 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2345 		return 0;
2346 
2347 	return 1;
2348 }
2349 
2350 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2351 			      struct ext4_group_desc *gdp)
2352 {
2353 	if (!ext4_has_group_desc_csum(sb))
2354 		return;
2355 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2356 }
2357 
2358 /* Called at mount-time, super-block is locked */
2359 static int ext4_check_descriptors(struct super_block *sb,
2360 				  ext4_fsblk_t sb_block,
2361 				  ext4_group_t *first_not_zeroed)
2362 {
2363 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2364 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2365 	ext4_fsblk_t last_block;
2366 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2367 	ext4_fsblk_t block_bitmap;
2368 	ext4_fsblk_t inode_bitmap;
2369 	ext4_fsblk_t inode_table;
2370 	int flexbg_flag = 0;
2371 	ext4_group_t i, grp = sbi->s_groups_count;
2372 
2373 	if (ext4_has_feature_flex_bg(sb))
2374 		flexbg_flag = 1;
2375 
2376 	ext4_debug("Checking group descriptors");
2377 
2378 	for (i = 0; i < sbi->s_groups_count; i++) {
2379 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2380 
2381 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2382 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2383 		else
2384 			last_block = first_block +
2385 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2386 
2387 		if ((grp == sbi->s_groups_count) &&
2388 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2389 			grp = i;
2390 
2391 		block_bitmap = ext4_block_bitmap(sb, gdp);
2392 		if (block_bitmap == sb_block) {
2393 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2394 				 "Block bitmap for group %u overlaps "
2395 				 "superblock", i);
2396 			if (!sb_rdonly(sb))
2397 				return 0;
2398 		}
2399 		if (block_bitmap >= sb_block + 1 &&
2400 		    block_bitmap <= last_bg_block) {
2401 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2402 				 "Block bitmap for group %u overlaps "
2403 				 "block group descriptors", i);
2404 			if (!sb_rdonly(sb))
2405 				return 0;
2406 		}
2407 		if (block_bitmap < first_block || block_bitmap > last_block) {
2408 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2409 			       "Block bitmap for group %u not in group "
2410 			       "(block %llu)!", i, block_bitmap);
2411 			return 0;
2412 		}
2413 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2414 		if (inode_bitmap == sb_block) {
2415 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2416 				 "Inode bitmap for group %u overlaps "
2417 				 "superblock", i);
2418 			if (!sb_rdonly(sb))
2419 				return 0;
2420 		}
2421 		if (inode_bitmap >= sb_block + 1 &&
2422 		    inode_bitmap <= last_bg_block) {
2423 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2424 				 "Inode bitmap for group %u overlaps "
2425 				 "block group descriptors", i);
2426 			if (!sb_rdonly(sb))
2427 				return 0;
2428 		}
2429 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2430 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2431 			       "Inode bitmap for group %u not in group "
2432 			       "(block %llu)!", i, inode_bitmap);
2433 			return 0;
2434 		}
2435 		inode_table = ext4_inode_table(sb, gdp);
2436 		if (inode_table == sb_block) {
2437 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2438 				 "Inode table for group %u overlaps "
2439 				 "superblock", i);
2440 			if (!sb_rdonly(sb))
2441 				return 0;
2442 		}
2443 		if (inode_table >= sb_block + 1 &&
2444 		    inode_table <= last_bg_block) {
2445 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2446 				 "Inode table for group %u overlaps "
2447 				 "block group descriptors", i);
2448 			if (!sb_rdonly(sb))
2449 				return 0;
2450 		}
2451 		if (inode_table < first_block ||
2452 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2453 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2454 			       "Inode table for group %u not in group "
2455 			       "(block %llu)!", i, inode_table);
2456 			return 0;
2457 		}
2458 		ext4_lock_group(sb, i);
2459 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2460 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2461 				 "Checksum for group %u failed (%u!=%u)",
2462 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2463 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2464 			if (!sb_rdonly(sb)) {
2465 				ext4_unlock_group(sb, i);
2466 				return 0;
2467 			}
2468 		}
2469 		ext4_unlock_group(sb, i);
2470 		if (!flexbg_flag)
2471 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2472 	}
2473 	if (NULL != first_not_zeroed)
2474 		*first_not_zeroed = grp;
2475 	return 1;
2476 }
2477 
2478 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2479  * the superblock) which were deleted from all directories, but held open by
2480  * a process at the time of a crash.  We walk the list and try to delete these
2481  * inodes at recovery time (only with a read-write filesystem).
2482  *
2483  * In order to keep the orphan inode chain consistent during traversal (in
2484  * case of crash during recovery), we link each inode into the superblock
2485  * orphan list_head and handle it the same way as an inode deletion during
2486  * normal operation (which journals the operations for us).
2487  *
2488  * We only do an iget() and an iput() on each inode, which is very safe if we
2489  * accidentally point at an in-use or already deleted inode.  The worst that
2490  * can happen in this case is that we get a "bit already cleared" message from
2491  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2492  * e2fsck was run on this filesystem, and it must have already done the orphan
2493  * inode cleanup for us, so we can safely abort without any further action.
2494  */
2495 static void ext4_orphan_cleanup(struct super_block *sb,
2496 				struct ext4_super_block *es)
2497 {
2498 	unsigned int s_flags = sb->s_flags;
2499 	int ret, nr_orphans = 0, nr_truncates = 0;
2500 #ifdef CONFIG_QUOTA
2501 	int quota_update = 0;
2502 	int i;
2503 #endif
2504 	if (!es->s_last_orphan) {
2505 		jbd_debug(4, "no orphan inodes to clean up\n");
2506 		return;
2507 	}
2508 
2509 	if (bdev_read_only(sb->s_bdev)) {
2510 		ext4_msg(sb, KERN_ERR, "write access "
2511 			"unavailable, skipping orphan cleanup");
2512 		return;
2513 	}
2514 
2515 	/* Check if feature set would not allow a r/w mount */
2516 	if (!ext4_feature_set_ok(sb, 0)) {
2517 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2518 			 "unknown ROCOMPAT features");
2519 		return;
2520 	}
2521 
2522 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2523 		/* don't clear list on RO mount w/ errors */
2524 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2525 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2526 				  "clearing orphan list.\n");
2527 			es->s_last_orphan = 0;
2528 		}
2529 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2530 		return;
2531 	}
2532 
2533 	if (s_flags & SB_RDONLY) {
2534 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2535 		sb->s_flags &= ~SB_RDONLY;
2536 	}
2537 #ifdef CONFIG_QUOTA
2538 	/* Needed for iput() to work correctly and not trash data */
2539 	sb->s_flags |= SB_ACTIVE;
2540 
2541 	/*
2542 	 * Turn on quotas which were not enabled for read-only mounts if
2543 	 * filesystem has quota feature, so that they are updated correctly.
2544 	 */
2545 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2546 		int ret = ext4_enable_quotas(sb);
2547 
2548 		if (!ret)
2549 			quota_update = 1;
2550 		else
2551 			ext4_msg(sb, KERN_ERR,
2552 				"Cannot turn on quotas: error %d", ret);
2553 	}
2554 
2555 	/* Turn on journaled quotas used for old sytle */
2556 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2557 		if (EXT4_SB(sb)->s_qf_names[i]) {
2558 			int ret = ext4_quota_on_mount(sb, i);
2559 
2560 			if (!ret)
2561 				quota_update = 1;
2562 			else
2563 				ext4_msg(sb, KERN_ERR,
2564 					"Cannot turn on journaled "
2565 					"quota: type %d: error %d", i, ret);
2566 		}
2567 	}
2568 #endif
2569 
2570 	while (es->s_last_orphan) {
2571 		struct inode *inode;
2572 
2573 		/*
2574 		 * We may have encountered an error during cleanup; if
2575 		 * so, skip the rest.
2576 		 */
2577 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2578 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2579 			es->s_last_orphan = 0;
2580 			break;
2581 		}
2582 
2583 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2584 		if (IS_ERR(inode)) {
2585 			es->s_last_orphan = 0;
2586 			break;
2587 		}
2588 
2589 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2590 		dquot_initialize(inode);
2591 		if (inode->i_nlink) {
2592 			if (test_opt(sb, DEBUG))
2593 				ext4_msg(sb, KERN_DEBUG,
2594 					"%s: truncating inode %lu to %lld bytes",
2595 					__func__, inode->i_ino, inode->i_size);
2596 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2597 				  inode->i_ino, inode->i_size);
2598 			inode_lock(inode);
2599 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2600 			ret = ext4_truncate(inode);
2601 			if (ret)
2602 				ext4_std_error(inode->i_sb, ret);
2603 			inode_unlock(inode);
2604 			nr_truncates++;
2605 		} else {
2606 			if (test_opt(sb, DEBUG))
2607 				ext4_msg(sb, KERN_DEBUG,
2608 					"%s: deleting unreferenced inode %lu",
2609 					__func__, inode->i_ino);
2610 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2611 				  inode->i_ino);
2612 			nr_orphans++;
2613 		}
2614 		iput(inode);  /* The delete magic happens here! */
2615 	}
2616 
2617 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2618 
2619 	if (nr_orphans)
2620 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2621 		       PLURAL(nr_orphans));
2622 	if (nr_truncates)
2623 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2624 		       PLURAL(nr_truncates));
2625 #ifdef CONFIG_QUOTA
2626 	/* Turn off quotas if they were enabled for orphan cleanup */
2627 	if (quota_update) {
2628 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2629 			if (sb_dqopt(sb)->files[i])
2630 				dquot_quota_off(sb, i);
2631 		}
2632 	}
2633 #endif
2634 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2635 }
2636 
2637 /*
2638  * Maximal extent format file size.
2639  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2640  * extent format containers, within a sector_t, and within i_blocks
2641  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2642  * so that won't be a limiting factor.
2643  *
2644  * However there is other limiting factor. We do store extents in the form
2645  * of starting block and length, hence the resulting length of the extent
2646  * covering maximum file size must fit into on-disk format containers as
2647  * well. Given that length is always by 1 unit bigger than max unit (because
2648  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2649  *
2650  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2651  */
2652 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2653 {
2654 	loff_t res;
2655 	loff_t upper_limit = MAX_LFS_FILESIZE;
2656 
2657 	/* small i_blocks in vfs inode? */
2658 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2659 		/*
2660 		 * CONFIG_LBDAF is not enabled implies the inode
2661 		 * i_block represent total blocks in 512 bytes
2662 		 * 32 == size of vfs inode i_blocks * 8
2663 		 */
2664 		upper_limit = (1LL << 32) - 1;
2665 
2666 		/* total blocks in file system block size */
2667 		upper_limit >>= (blkbits - 9);
2668 		upper_limit <<= blkbits;
2669 	}
2670 
2671 	/*
2672 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2673 	 * by one fs block, so ee_len can cover the extent of maximum file
2674 	 * size
2675 	 */
2676 	res = (1LL << 32) - 1;
2677 	res <<= blkbits;
2678 
2679 	/* Sanity check against vm- & vfs- imposed limits */
2680 	if (res > upper_limit)
2681 		res = upper_limit;
2682 
2683 	return res;
2684 }
2685 
2686 /*
2687  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2688  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2689  * We need to be 1 filesystem block less than the 2^48 sector limit.
2690  */
2691 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2692 {
2693 	loff_t res = EXT4_NDIR_BLOCKS;
2694 	int meta_blocks;
2695 	loff_t upper_limit;
2696 	/* This is calculated to be the largest file size for a dense, block
2697 	 * mapped file such that the file's total number of 512-byte sectors,
2698 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2699 	 *
2700 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2701 	 * number of 512-byte sectors of the file.
2702 	 */
2703 
2704 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2705 		/*
2706 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2707 		 * the inode i_block field represents total file blocks in
2708 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2709 		 */
2710 		upper_limit = (1LL << 32) - 1;
2711 
2712 		/* total blocks in file system block size */
2713 		upper_limit >>= (bits - 9);
2714 
2715 	} else {
2716 		/*
2717 		 * We use 48 bit ext4_inode i_blocks
2718 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2719 		 * represent total number of blocks in
2720 		 * file system block size
2721 		 */
2722 		upper_limit = (1LL << 48) - 1;
2723 
2724 	}
2725 
2726 	/* indirect blocks */
2727 	meta_blocks = 1;
2728 	/* double indirect blocks */
2729 	meta_blocks += 1 + (1LL << (bits-2));
2730 	/* tripple indirect blocks */
2731 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2732 
2733 	upper_limit -= meta_blocks;
2734 	upper_limit <<= bits;
2735 
2736 	res += 1LL << (bits-2);
2737 	res += 1LL << (2*(bits-2));
2738 	res += 1LL << (3*(bits-2));
2739 	res <<= bits;
2740 	if (res > upper_limit)
2741 		res = upper_limit;
2742 
2743 	if (res > MAX_LFS_FILESIZE)
2744 		res = MAX_LFS_FILESIZE;
2745 
2746 	return res;
2747 }
2748 
2749 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2750 				   ext4_fsblk_t logical_sb_block, int nr)
2751 {
2752 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2753 	ext4_group_t bg, first_meta_bg;
2754 	int has_super = 0;
2755 
2756 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2757 
2758 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2759 		return logical_sb_block + nr + 1;
2760 	bg = sbi->s_desc_per_block * nr;
2761 	if (ext4_bg_has_super(sb, bg))
2762 		has_super = 1;
2763 
2764 	/*
2765 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2766 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2767 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2768 	 * compensate.
2769 	 */
2770 	if (sb->s_blocksize == 1024 && nr == 0 &&
2771 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2772 		has_super++;
2773 
2774 	return (has_super + ext4_group_first_block_no(sb, bg));
2775 }
2776 
2777 /**
2778  * ext4_get_stripe_size: Get the stripe size.
2779  * @sbi: In memory super block info
2780  *
2781  * If we have specified it via mount option, then
2782  * use the mount option value. If the value specified at mount time is
2783  * greater than the blocks per group use the super block value.
2784  * If the super block value is greater than blocks per group return 0.
2785  * Allocator needs it be less than blocks per group.
2786  *
2787  */
2788 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2789 {
2790 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2791 	unsigned long stripe_width =
2792 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2793 	int ret;
2794 
2795 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2796 		ret = sbi->s_stripe;
2797 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2798 		ret = stripe_width;
2799 	else if (stride && stride <= sbi->s_blocks_per_group)
2800 		ret = stride;
2801 	else
2802 		ret = 0;
2803 
2804 	/*
2805 	 * If the stripe width is 1, this makes no sense and
2806 	 * we set it to 0 to turn off stripe handling code.
2807 	 */
2808 	if (ret <= 1)
2809 		ret = 0;
2810 
2811 	return ret;
2812 }
2813 
2814 /*
2815  * Check whether this filesystem can be mounted based on
2816  * the features present and the RDONLY/RDWR mount requested.
2817  * Returns 1 if this filesystem can be mounted as requested,
2818  * 0 if it cannot be.
2819  */
2820 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2821 {
2822 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2823 		ext4_msg(sb, KERN_ERR,
2824 			"Couldn't mount because of "
2825 			"unsupported optional features (%x)",
2826 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2827 			~EXT4_FEATURE_INCOMPAT_SUPP));
2828 		return 0;
2829 	}
2830 
2831 	if (readonly)
2832 		return 1;
2833 
2834 	if (ext4_has_feature_readonly(sb)) {
2835 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2836 		sb->s_flags |= SB_RDONLY;
2837 		return 1;
2838 	}
2839 
2840 	/* Check that feature set is OK for a read-write mount */
2841 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2842 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2843 			 "unsupported optional features (%x)",
2844 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2845 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2846 		return 0;
2847 	}
2848 	/*
2849 	 * Large file size enabled file system can only be mounted
2850 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2851 	 */
2852 	if (ext4_has_feature_huge_file(sb)) {
2853 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2854 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2855 				 "cannot be mounted RDWR without "
2856 				 "CONFIG_LBDAF");
2857 			return 0;
2858 		}
2859 	}
2860 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2861 		ext4_msg(sb, KERN_ERR,
2862 			 "Can't support bigalloc feature without "
2863 			 "extents feature\n");
2864 		return 0;
2865 	}
2866 
2867 #ifndef CONFIG_QUOTA
2868 	if (ext4_has_feature_quota(sb) && !readonly) {
2869 		ext4_msg(sb, KERN_ERR,
2870 			 "Filesystem with quota feature cannot be mounted RDWR "
2871 			 "without CONFIG_QUOTA");
2872 		return 0;
2873 	}
2874 	if (ext4_has_feature_project(sb) && !readonly) {
2875 		ext4_msg(sb, KERN_ERR,
2876 			 "Filesystem with project quota feature cannot be mounted RDWR "
2877 			 "without CONFIG_QUOTA");
2878 		return 0;
2879 	}
2880 #endif  /* CONFIG_QUOTA */
2881 	return 1;
2882 }
2883 
2884 /*
2885  * This function is called once a day if we have errors logged
2886  * on the file system
2887  */
2888 static void print_daily_error_info(struct timer_list *t)
2889 {
2890 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2891 	struct super_block *sb = sbi->s_sb;
2892 	struct ext4_super_block *es = sbi->s_es;
2893 
2894 	if (es->s_error_count)
2895 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2896 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2897 			 le32_to_cpu(es->s_error_count));
2898 	if (es->s_first_error_time) {
2899 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
2900 		       sb->s_id,
2901 		       ext4_get_tstamp(es, s_first_error_time),
2902 		       (int) sizeof(es->s_first_error_func),
2903 		       es->s_first_error_func,
2904 		       le32_to_cpu(es->s_first_error_line));
2905 		if (es->s_first_error_ino)
2906 			printk(KERN_CONT ": inode %u",
2907 			       le32_to_cpu(es->s_first_error_ino));
2908 		if (es->s_first_error_block)
2909 			printk(KERN_CONT ": block %llu", (unsigned long long)
2910 			       le64_to_cpu(es->s_first_error_block));
2911 		printk(KERN_CONT "\n");
2912 	}
2913 	if (es->s_last_error_time) {
2914 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
2915 		       sb->s_id,
2916 		       ext4_get_tstamp(es, s_last_error_time),
2917 		       (int) sizeof(es->s_last_error_func),
2918 		       es->s_last_error_func,
2919 		       le32_to_cpu(es->s_last_error_line));
2920 		if (es->s_last_error_ino)
2921 			printk(KERN_CONT ": inode %u",
2922 			       le32_to_cpu(es->s_last_error_ino));
2923 		if (es->s_last_error_block)
2924 			printk(KERN_CONT ": block %llu", (unsigned long long)
2925 			       le64_to_cpu(es->s_last_error_block));
2926 		printk(KERN_CONT "\n");
2927 	}
2928 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2929 }
2930 
2931 /* Find next suitable group and run ext4_init_inode_table */
2932 static int ext4_run_li_request(struct ext4_li_request *elr)
2933 {
2934 	struct ext4_group_desc *gdp = NULL;
2935 	ext4_group_t group, ngroups;
2936 	struct super_block *sb;
2937 	unsigned long timeout = 0;
2938 	int ret = 0;
2939 
2940 	sb = elr->lr_super;
2941 	ngroups = EXT4_SB(sb)->s_groups_count;
2942 
2943 	for (group = elr->lr_next_group; group < ngroups; group++) {
2944 		gdp = ext4_get_group_desc(sb, group, NULL);
2945 		if (!gdp) {
2946 			ret = 1;
2947 			break;
2948 		}
2949 
2950 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2951 			break;
2952 	}
2953 
2954 	if (group >= ngroups)
2955 		ret = 1;
2956 
2957 	if (!ret) {
2958 		timeout = jiffies;
2959 		ret = ext4_init_inode_table(sb, group,
2960 					    elr->lr_timeout ? 0 : 1);
2961 		if (elr->lr_timeout == 0) {
2962 			timeout = (jiffies - timeout) *
2963 				  elr->lr_sbi->s_li_wait_mult;
2964 			elr->lr_timeout = timeout;
2965 		}
2966 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2967 		elr->lr_next_group = group + 1;
2968 	}
2969 	return ret;
2970 }
2971 
2972 /*
2973  * Remove lr_request from the list_request and free the
2974  * request structure. Should be called with li_list_mtx held
2975  */
2976 static void ext4_remove_li_request(struct ext4_li_request *elr)
2977 {
2978 	struct ext4_sb_info *sbi;
2979 
2980 	if (!elr)
2981 		return;
2982 
2983 	sbi = elr->lr_sbi;
2984 
2985 	list_del(&elr->lr_request);
2986 	sbi->s_li_request = NULL;
2987 	kfree(elr);
2988 }
2989 
2990 static void ext4_unregister_li_request(struct super_block *sb)
2991 {
2992 	mutex_lock(&ext4_li_mtx);
2993 	if (!ext4_li_info) {
2994 		mutex_unlock(&ext4_li_mtx);
2995 		return;
2996 	}
2997 
2998 	mutex_lock(&ext4_li_info->li_list_mtx);
2999 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3000 	mutex_unlock(&ext4_li_info->li_list_mtx);
3001 	mutex_unlock(&ext4_li_mtx);
3002 }
3003 
3004 static struct task_struct *ext4_lazyinit_task;
3005 
3006 /*
3007  * This is the function where ext4lazyinit thread lives. It walks
3008  * through the request list searching for next scheduled filesystem.
3009  * When such a fs is found, run the lazy initialization request
3010  * (ext4_rn_li_request) and keep track of the time spend in this
3011  * function. Based on that time we compute next schedule time of
3012  * the request. When walking through the list is complete, compute
3013  * next waking time and put itself into sleep.
3014  */
3015 static int ext4_lazyinit_thread(void *arg)
3016 {
3017 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3018 	struct list_head *pos, *n;
3019 	struct ext4_li_request *elr;
3020 	unsigned long next_wakeup, cur;
3021 
3022 	BUG_ON(NULL == eli);
3023 
3024 cont_thread:
3025 	while (true) {
3026 		next_wakeup = MAX_JIFFY_OFFSET;
3027 
3028 		mutex_lock(&eli->li_list_mtx);
3029 		if (list_empty(&eli->li_request_list)) {
3030 			mutex_unlock(&eli->li_list_mtx);
3031 			goto exit_thread;
3032 		}
3033 		list_for_each_safe(pos, n, &eli->li_request_list) {
3034 			int err = 0;
3035 			int progress = 0;
3036 			elr = list_entry(pos, struct ext4_li_request,
3037 					 lr_request);
3038 
3039 			if (time_before(jiffies, elr->lr_next_sched)) {
3040 				if (time_before(elr->lr_next_sched, next_wakeup))
3041 					next_wakeup = elr->lr_next_sched;
3042 				continue;
3043 			}
3044 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3045 				if (sb_start_write_trylock(elr->lr_super)) {
3046 					progress = 1;
3047 					/*
3048 					 * We hold sb->s_umount, sb can not
3049 					 * be removed from the list, it is
3050 					 * now safe to drop li_list_mtx
3051 					 */
3052 					mutex_unlock(&eli->li_list_mtx);
3053 					err = ext4_run_li_request(elr);
3054 					sb_end_write(elr->lr_super);
3055 					mutex_lock(&eli->li_list_mtx);
3056 					n = pos->next;
3057 				}
3058 				up_read((&elr->lr_super->s_umount));
3059 			}
3060 			/* error, remove the lazy_init job */
3061 			if (err) {
3062 				ext4_remove_li_request(elr);
3063 				continue;
3064 			}
3065 			if (!progress) {
3066 				elr->lr_next_sched = jiffies +
3067 					(prandom_u32()
3068 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3069 			}
3070 			if (time_before(elr->lr_next_sched, next_wakeup))
3071 				next_wakeup = elr->lr_next_sched;
3072 		}
3073 		mutex_unlock(&eli->li_list_mtx);
3074 
3075 		try_to_freeze();
3076 
3077 		cur = jiffies;
3078 		if ((time_after_eq(cur, next_wakeup)) ||
3079 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3080 			cond_resched();
3081 			continue;
3082 		}
3083 
3084 		schedule_timeout_interruptible(next_wakeup - cur);
3085 
3086 		if (kthread_should_stop()) {
3087 			ext4_clear_request_list();
3088 			goto exit_thread;
3089 		}
3090 	}
3091 
3092 exit_thread:
3093 	/*
3094 	 * It looks like the request list is empty, but we need
3095 	 * to check it under the li_list_mtx lock, to prevent any
3096 	 * additions into it, and of course we should lock ext4_li_mtx
3097 	 * to atomically free the list and ext4_li_info, because at
3098 	 * this point another ext4 filesystem could be registering
3099 	 * new one.
3100 	 */
3101 	mutex_lock(&ext4_li_mtx);
3102 	mutex_lock(&eli->li_list_mtx);
3103 	if (!list_empty(&eli->li_request_list)) {
3104 		mutex_unlock(&eli->li_list_mtx);
3105 		mutex_unlock(&ext4_li_mtx);
3106 		goto cont_thread;
3107 	}
3108 	mutex_unlock(&eli->li_list_mtx);
3109 	kfree(ext4_li_info);
3110 	ext4_li_info = NULL;
3111 	mutex_unlock(&ext4_li_mtx);
3112 
3113 	return 0;
3114 }
3115 
3116 static void ext4_clear_request_list(void)
3117 {
3118 	struct list_head *pos, *n;
3119 	struct ext4_li_request *elr;
3120 
3121 	mutex_lock(&ext4_li_info->li_list_mtx);
3122 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3123 		elr = list_entry(pos, struct ext4_li_request,
3124 				 lr_request);
3125 		ext4_remove_li_request(elr);
3126 	}
3127 	mutex_unlock(&ext4_li_info->li_list_mtx);
3128 }
3129 
3130 static int ext4_run_lazyinit_thread(void)
3131 {
3132 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3133 					 ext4_li_info, "ext4lazyinit");
3134 	if (IS_ERR(ext4_lazyinit_task)) {
3135 		int err = PTR_ERR(ext4_lazyinit_task);
3136 		ext4_clear_request_list();
3137 		kfree(ext4_li_info);
3138 		ext4_li_info = NULL;
3139 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3140 				 "initialization thread\n",
3141 				 err);
3142 		return err;
3143 	}
3144 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3145 	return 0;
3146 }
3147 
3148 /*
3149  * Check whether it make sense to run itable init. thread or not.
3150  * If there is at least one uninitialized inode table, return
3151  * corresponding group number, else the loop goes through all
3152  * groups and return total number of groups.
3153  */
3154 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3155 {
3156 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3157 	struct ext4_group_desc *gdp = NULL;
3158 
3159 	if (!ext4_has_group_desc_csum(sb))
3160 		return ngroups;
3161 
3162 	for (group = 0; group < ngroups; group++) {
3163 		gdp = ext4_get_group_desc(sb, group, NULL);
3164 		if (!gdp)
3165 			continue;
3166 
3167 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3168 			break;
3169 	}
3170 
3171 	return group;
3172 }
3173 
3174 static int ext4_li_info_new(void)
3175 {
3176 	struct ext4_lazy_init *eli = NULL;
3177 
3178 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3179 	if (!eli)
3180 		return -ENOMEM;
3181 
3182 	INIT_LIST_HEAD(&eli->li_request_list);
3183 	mutex_init(&eli->li_list_mtx);
3184 
3185 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3186 
3187 	ext4_li_info = eli;
3188 
3189 	return 0;
3190 }
3191 
3192 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3193 					    ext4_group_t start)
3194 {
3195 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3196 	struct ext4_li_request *elr;
3197 
3198 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3199 	if (!elr)
3200 		return NULL;
3201 
3202 	elr->lr_super = sb;
3203 	elr->lr_sbi = sbi;
3204 	elr->lr_next_group = start;
3205 
3206 	/*
3207 	 * Randomize first schedule time of the request to
3208 	 * spread the inode table initialization requests
3209 	 * better.
3210 	 */
3211 	elr->lr_next_sched = jiffies + (prandom_u32() %
3212 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3213 	return elr;
3214 }
3215 
3216 int ext4_register_li_request(struct super_block *sb,
3217 			     ext4_group_t first_not_zeroed)
3218 {
3219 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3220 	struct ext4_li_request *elr = NULL;
3221 	ext4_group_t ngroups = sbi->s_groups_count;
3222 	int ret = 0;
3223 
3224 	mutex_lock(&ext4_li_mtx);
3225 	if (sbi->s_li_request != NULL) {
3226 		/*
3227 		 * Reset timeout so it can be computed again, because
3228 		 * s_li_wait_mult might have changed.
3229 		 */
3230 		sbi->s_li_request->lr_timeout = 0;
3231 		goto out;
3232 	}
3233 
3234 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3235 	    !test_opt(sb, INIT_INODE_TABLE))
3236 		goto out;
3237 
3238 	elr = ext4_li_request_new(sb, first_not_zeroed);
3239 	if (!elr) {
3240 		ret = -ENOMEM;
3241 		goto out;
3242 	}
3243 
3244 	if (NULL == ext4_li_info) {
3245 		ret = ext4_li_info_new();
3246 		if (ret)
3247 			goto out;
3248 	}
3249 
3250 	mutex_lock(&ext4_li_info->li_list_mtx);
3251 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3252 	mutex_unlock(&ext4_li_info->li_list_mtx);
3253 
3254 	sbi->s_li_request = elr;
3255 	/*
3256 	 * set elr to NULL here since it has been inserted to
3257 	 * the request_list and the removal and free of it is
3258 	 * handled by ext4_clear_request_list from now on.
3259 	 */
3260 	elr = NULL;
3261 
3262 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3263 		ret = ext4_run_lazyinit_thread();
3264 		if (ret)
3265 			goto out;
3266 	}
3267 out:
3268 	mutex_unlock(&ext4_li_mtx);
3269 	if (ret)
3270 		kfree(elr);
3271 	return ret;
3272 }
3273 
3274 /*
3275  * We do not need to lock anything since this is called on
3276  * module unload.
3277  */
3278 static void ext4_destroy_lazyinit_thread(void)
3279 {
3280 	/*
3281 	 * If thread exited earlier
3282 	 * there's nothing to be done.
3283 	 */
3284 	if (!ext4_li_info || !ext4_lazyinit_task)
3285 		return;
3286 
3287 	kthread_stop(ext4_lazyinit_task);
3288 }
3289 
3290 static int set_journal_csum_feature_set(struct super_block *sb)
3291 {
3292 	int ret = 1;
3293 	int compat, incompat;
3294 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3295 
3296 	if (ext4_has_metadata_csum(sb)) {
3297 		/* journal checksum v3 */
3298 		compat = 0;
3299 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3300 	} else {
3301 		/* journal checksum v1 */
3302 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3303 		incompat = 0;
3304 	}
3305 
3306 	jbd2_journal_clear_features(sbi->s_journal,
3307 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3308 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3309 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3310 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3311 		ret = jbd2_journal_set_features(sbi->s_journal,
3312 				compat, 0,
3313 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3314 				incompat);
3315 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3316 		ret = jbd2_journal_set_features(sbi->s_journal,
3317 				compat, 0,
3318 				incompat);
3319 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3320 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3321 	} else {
3322 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3323 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3324 	}
3325 
3326 	return ret;
3327 }
3328 
3329 /*
3330  * Note: calculating the overhead so we can be compatible with
3331  * historical BSD practice is quite difficult in the face of
3332  * clusters/bigalloc.  This is because multiple metadata blocks from
3333  * different block group can end up in the same allocation cluster.
3334  * Calculating the exact overhead in the face of clustered allocation
3335  * requires either O(all block bitmaps) in memory or O(number of block
3336  * groups**2) in time.  We will still calculate the superblock for
3337  * older file systems --- and if we come across with a bigalloc file
3338  * system with zero in s_overhead_clusters the estimate will be close to
3339  * correct especially for very large cluster sizes --- but for newer
3340  * file systems, it's better to calculate this figure once at mkfs
3341  * time, and store it in the superblock.  If the superblock value is
3342  * present (even for non-bigalloc file systems), we will use it.
3343  */
3344 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3345 			  char *buf)
3346 {
3347 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3348 	struct ext4_group_desc	*gdp;
3349 	ext4_fsblk_t		first_block, last_block, b;
3350 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3351 	int			s, j, count = 0;
3352 
3353 	if (!ext4_has_feature_bigalloc(sb))
3354 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3355 			sbi->s_itb_per_group + 2);
3356 
3357 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3358 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3359 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3360 	for (i = 0; i < ngroups; i++) {
3361 		gdp = ext4_get_group_desc(sb, i, NULL);
3362 		b = ext4_block_bitmap(sb, gdp);
3363 		if (b >= first_block && b <= last_block) {
3364 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3365 			count++;
3366 		}
3367 		b = ext4_inode_bitmap(sb, gdp);
3368 		if (b >= first_block && b <= last_block) {
3369 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3370 			count++;
3371 		}
3372 		b = ext4_inode_table(sb, gdp);
3373 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3374 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3375 				int c = EXT4_B2C(sbi, b - first_block);
3376 				ext4_set_bit(c, buf);
3377 				count++;
3378 			}
3379 		if (i != grp)
3380 			continue;
3381 		s = 0;
3382 		if (ext4_bg_has_super(sb, grp)) {
3383 			ext4_set_bit(s++, buf);
3384 			count++;
3385 		}
3386 		j = ext4_bg_num_gdb(sb, grp);
3387 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3388 			ext4_error(sb, "Invalid number of block group "
3389 				   "descriptor blocks: %d", j);
3390 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3391 		}
3392 		count += j;
3393 		for (; j > 0; j--)
3394 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3395 	}
3396 	if (!count)
3397 		return 0;
3398 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3399 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3400 }
3401 
3402 /*
3403  * Compute the overhead and stash it in sbi->s_overhead
3404  */
3405 int ext4_calculate_overhead(struct super_block *sb)
3406 {
3407 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3408 	struct ext4_super_block *es = sbi->s_es;
3409 	struct inode *j_inode;
3410 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3411 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3412 	ext4_fsblk_t overhead = 0;
3413 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3414 
3415 	if (!buf)
3416 		return -ENOMEM;
3417 
3418 	/*
3419 	 * Compute the overhead (FS structures).  This is constant
3420 	 * for a given filesystem unless the number of block groups
3421 	 * changes so we cache the previous value until it does.
3422 	 */
3423 
3424 	/*
3425 	 * All of the blocks before first_data_block are overhead
3426 	 */
3427 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3428 
3429 	/*
3430 	 * Add the overhead found in each block group
3431 	 */
3432 	for (i = 0; i < ngroups; i++) {
3433 		int blks;
3434 
3435 		blks = count_overhead(sb, i, buf);
3436 		overhead += blks;
3437 		if (blks)
3438 			memset(buf, 0, PAGE_SIZE);
3439 		cond_resched();
3440 	}
3441 
3442 	/*
3443 	 * Add the internal journal blocks whether the journal has been
3444 	 * loaded or not
3445 	 */
3446 	if (sbi->s_journal && !sbi->journal_bdev)
3447 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3448 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3449 		j_inode = ext4_get_journal_inode(sb, j_inum);
3450 		if (j_inode) {
3451 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3452 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3453 			iput(j_inode);
3454 		} else {
3455 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3456 		}
3457 	}
3458 	sbi->s_overhead = overhead;
3459 	smp_wmb();
3460 	free_page((unsigned long) buf);
3461 	return 0;
3462 }
3463 
3464 static void ext4_set_resv_clusters(struct super_block *sb)
3465 {
3466 	ext4_fsblk_t resv_clusters;
3467 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3468 
3469 	/*
3470 	 * There's no need to reserve anything when we aren't using extents.
3471 	 * The space estimates are exact, there are no unwritten extents,
3472 	 * hole punching doesn't need new metadata... This is needed especially
3473 	 * to keep ext2/3 backward compatibility.
3474 	 */
3475 	if (!ext4_has_feature_extents(sb))
3476 		return;
3477 	/*
3478 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3479 	 * This should cover the situations where we can not afford to run
3480 	 * out of space like for example punch hole, or converting
3481 	 * unwritten extents in delalloc path. In most cases such
3482 	 * allocation would require 1, or 2 blocks, higher numbers are
3483 	 * very rare.
3484 	 */
3485 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3486 			 sbi->s_cluster_bits);
3487 
3488 	do_div(resv_clusters, 50);
3489 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3490 
3491 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3492 }
3493 
3494 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3495 {
3496 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3497 	char *orig_data = kstrdup(data, GFP_KERNEL);
3498 	struct buffer_head *bh;
3499 	struct ext4_super_block *es = NULL;
3500 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3501 	ext4_fsblk_t block;
3502 	ext4_fsblk_t sb_block = get_sb_block(&data);
3503 	ext4_fsblk_t logical_sb_block;
3504 	unsigned long offset = 0;
3505 	unsigned long journal_devnum = 0;
3506 	unsigned long def_mount_opts;
3507 	struct inode *root;
3508 	const char *descr;
3509 	int ret = -ENOMEM;
3510 	int blocksize, clustersize;
3511 	unsigned int db_count;
3512 	unsigned int i;
3513 	int needs_recovery, has_huge_files, has_bigalloc;
3514 	__u64 blocks_count;
3515 	int err = 0;
3516 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3517 	ext4_group_t first_not_zeroed;
3518 
3519 	if ((data && !orig_data) || !sbi)
3520 		goto out_free_base;
3521 
3522 	sbi->s_daxdev = dax_dev;
3523 	sbi->s_blockgroup_lock =
3524 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3525 	if (!sbi->s_blockgroup_lock)
3526 		goto out_free_base;
3527 
3528 	sb->s_fs_info = sbi;
3529 	sbi->s_sb = sb;
3530 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3531 	sbi->s_sb_block = sb_block;
3532 	if (sb->s_bdev->bd_part)
3533 		sbi->s_sectors_written_start =
3534 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3535 
3536 	/* Cleanup superblock name */
3537 	strreplace(sb->s_id, '/', '!');
3538 
3539 	/* -EINVAL is default */
3540 	ret = -EINVAL;
3541 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3542 	if (!blocksize) {
3543 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3544 		goto out_fail;
3545 	}
3546 
3547 	/*
3548 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3549 	 * block sizes.  We need to calculate the offset from buffer start.
3550 	 */
3551 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3552 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3553 		offset = do_div(logical_sb_block, blocksize);
3554 	} else {
3555 		logical_sb_block = sb_block;
3556 	}
3557 
3558 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3559 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3560 		goto out_fail;
3561 	}
3562 	/*
3563 	 * Note: s_es must be initialized as soon as possible because
3564 	 *       some ext4 macro-instructions depend on its value
3565 	 */
3566 	es = (struct ext4_super_block *) (bh->b_data + offset);
3567 	sbi->s_es = es;
3568 	sb->s_magic = le16_to_cpu(es->s_magic);
3569 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3570 		goto cantfind_ext4;
3571 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3572 
3573 	/* Warn if metadata_csum and gdt_csum are both set. */
3574 	if (ext4_has_feature_metadata_csum(sb) &&
3575 	    ext4_has_feature_gdt_csum(sb))
3576 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3577 			     "redundant flags; please run fsck.");
3578 
3579 	/* Check for a known checksum algorithm */
3580 	if (!ext4_verify_csum_type(sb, es)) {
3581 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3582 			 "unknown checksum algorithm.");
3583 		silent = 1;
3584 		goto cantfind_ext4;
3585 	}
3586 
3587 	/* Load the checksum driver */
3588 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3589 	if (IS_ERR(sbi->s_chksum_driver)) {
3590 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3591 		ret = PTR_ERR(sbi->s_chksum_driver);
3592 		sbi->s_chksum_driver = NULL;
3593 		goto failed_mount;
3594 	}
3595 
3596 	/* Check superblock checksum */
3597 	if (!ext4_superblock_csum_verify(sb, es)) {
3598 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3599 			 "invalid superblock checksum.  Run e2fsck?");
3600 		silent = 1;
3601 		ret = -EFSBADCRC;
3602 		goto cantfind_ext4;
3603 	}
3604 
3605 	/* Precompute checksum seed for all metadata */
3606 	if (ext4_has_feature_csum_seed(sb))
3607 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3608 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3609 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3610 					       sizeof(es->s_uuid));
3611 
3612 	/* Set defaults before we parse the mount options */
3613 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3614 	set_opt(sb, INIT_INODE_TABLE);
3615 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3616 		set_opt(sb, DEBUG);
3617 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3618 		set_opt(sb, GRPID);
3619 	if (def_mount_opts & EXT4_DEFM_UID16)
3620 		set_opt(sb, NO_UID32);
3621 	/* xattr user namespace & acls are now defaulted on */
3622 	set_opt(sb, XATTR_USER);
3623 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3624 	set_opt(sb, POSIX_ACL);
3625 #endif
3626 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3627 	if (ext4_has_metadata_csum(sb))
3628 		set_opt(sb, JOURNAL_CHECKSUM);
3629 
3630 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3631 		set_opt(sb, JOURNAL_DATA);
3632 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3633 		set_opt(sb, ORDERED_DATA);
3634 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3635 		set_opt(sb, WRITEBACK_DATA);
3636 
3637 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3638 		set_opt(sb, ERRORS_PANIC);
3639 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3640 		set_opt(sb, ERRORS_CONT);
3641 	else
3642 		set_opt(sb, ERRORS_RO);
3643 	/* block_validity enabled by default; disable with noblock_validity */
3644 	set_opt(sb, BLOCK_VALIDITY);
3645 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3646 		set_opt(sb, DISCARD);
3647 
3648 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3649 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3650 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3651 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3652 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3653 
3654 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3655 		set_opt(sb, BARRIER);
3656 
3657 	/*
3658 	 * enable delayed allocation by default
3659 	 * Use -o nodelalloc to turn it off
3660 	 */
3661 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3662 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3663 		set_opt(sb, DELALLOC);
3664 
3665 	/*
3666 	 * set default s_li_wait_mult for lazyinit, for the case there is
3667 	 * no mount option specified.
3668 	 */
3669 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3670 
3671 	if (sbi->s_es->s_mount_opts[0]) {
3672 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3673 					      sizeof(sbi->s_es->s_mount_opts),
3674 					      GFP_KERNEL);
3675 		if (!s_mount_opts)
3676 			goto failed_mount;
3677 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3678 				   &journal_ioprio, 0)) {
3679 			ext4_msg(sb, KERN_WARNING,
3680 				 "failed to parse options in superblock: %s",
3681 				 s_mount_opts);
3682 		}
3683 		kfree(s_mount_opts);
3684 	}
3685 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3686 	if (!parse_options((char *) data, sb, &journal_devnum,
3687 			   &journal_ioprio, 0))
3688 		goto failed_mount;
3689 
3690 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3691 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3692 			    "with data=journal disables delayed "
3693 			    "allocation and O_DIRECT support!\n");
3694 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3695 			ext4_msg(sb, KERN_ERR, "can't mount with "
3696 				 "both data=journal and delalloc");
3697 			goto failed_mount;
3698 		}
3699 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3700 			ext4_msg(sb, KERN_ERR, "can't mount with "
3701 				 "both data=journal and dioread_nolock");
3702 			goto failed_mount;
3703 		}
3704 		if (test_opt(sb, DAX)) {
3705 			ext4_msg(sb, KERN_ERR, "can't mount with "
3706 				 "both data=journal and dax");
3707 			goto failed_mount;
3708 		}
3709 		if (ext4_has_feature_encrypt(sb)) {
3710 			ext4_msg(sb, KERN_WARNING,
3711 				 "encrypted files will use data=ordered "
3712 				 "instead of data journaling mode");
3713 		}
3714 		if (test_opt(sb, DELALLOC))
3715 			clear_opt(sb, DELALLOC);
3716 	} else {
3717 		sb->s_iflags |= SB_I_CGROUPWB;
3718 	}
3719 
3720 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3721 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3722 
3723 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3724 	    (ext4_has_compat_features(sb) ||
3725 	     ext4_has_ro_compat_features(sb) ||
3726 	     ext4_has_incompat_features(sb)))
3727 		ext4_msg(sb, KERN_WARNING,
3728 		       "feature flags set on rev 0 fs, "
3729 		       "running e2fsck is recommended");
3730 
3731 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3732 		set_opt2(sb, HURD_COMPAT);
3733 		if (ext4_has_feature_64bit(sb)) {
3734 			ext4_msg(sb, KERN_ERR,
3735 				 "The Hurd can't support 64-bit file systems");
3736 			goto failed_mount;
3737 		}
3738 
3739 		/*
3740 		 * ea_inode feature uses l_i_version field which is not
3741 		 * available in HURD_COMPAT mode.
3742 		 */
3743 		if (ext4_has_feature_ea_inode(sb)) {
3744 			ext4_msg(sb, KERN_ERR,
3745 				 "ea_inode feature is not supported for Hurd");
3746 			goto failed_mount;
3747 		}
3748 	}
3749 
3750 	if (IS_EXT2_SB(sb)) {
3751 		if (ext2_feature_set_ok(sb))
3752 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3753 				 "using the ext4 subsystem");
3754 		else {
3755 			/*
3756 			 * If we're probing be silent, if this looks like
3757 			 * it's actually an ext[34] filesystem.
3758 			 */
3759 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3760 				goto failed_mount;
3761 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3762 				 "to feature incompatibilities");
3763 			goto failed_mount;
3764 		}
3765 	}
3766 
3767 	if (IS_EXT3_SB(sb)) {
3768 		if (ext3_feature_set_ok(sb))
3769 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3770 				 "using the ext4 subsystem");
3771 		else {
3772 			/*
3773 			 * If we're probing be silent, if this looks like
3774 			 * it's actually an ext4 filesystem.
3775 			 */
3776 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3777 				goto failed_mount;
3778 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3779 				 "to feature incompatibilities");
3780 			goto failed_mount;
3781 		}
3782 	}
3783 
3784 	/*
3785 	 * Check feature flags regardless of the revision level, since we
3786 	 * previously didn't change the revision level when setting the flags,
3787 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3788 	 */
3789 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3790 		goto failed_mount;
3791 
3792 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3793 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3794 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3795 		ext4_msg(sb, KERN_ERR,
3796 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3797 			 blocksize, le32_to_cpu(es->s_log_block_size));
3798 		goto failed_mount;
3799 	}
3800 	if (le32_to_cpu(es->s_log_block_size) >
3801 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3802 		ext4_msg(sb, KERN_ERR,
3803 			 "Invalid log block size: %u",
3804 			 le32_to_cpu(es->s_log_block_size));
3805 		goto failed_mount;
3806 	}
3807 	if (le32_to_cpu(es->s_log_cluster_size) >
3808 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3809 		ext4_msg(sb, KERN_ERR,
3810 			 "Invalid log cluster size: %u",
3811 			 le32_to_cpu(es->s_log_cluster_size));
3812 		goto failed_mount;
3813 	}
3814 
3815 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3816 		ext4_msg(sb, KERN_ERR,
3817 			 "Number of reserved GDT blocks insanely large: %d",
3818 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3819 		goto failed_mount;
3820 	}
3821 
3822 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3823 		if (ext4_has_feature_inline_data(sb)) {
3824 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3825 					" that may contain inline data");
3826 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
3827 		}
3828 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
3829 			ext4_msg(sb, KERN_ERR,
3830 				"DAX unsupported by block device. Turning off DAX.");
3831 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
3832 		}
3833 	}
3834 
3835 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3836 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3837 			 es->s_encryption_level);
3838 		goto failed_mount;
3839 	}
3840 
3841 	if (sb->s_blocksize != blocksize) {
3842 		/* Validate the filesystem blocksize */
3843 		if (!sb_set_blocksize(sb, blocksize)) {
3844 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3845 					blocksize);
3846 			goto failed_mount;
3847 		}
3848 
3849 		brelse(bh);
3850 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3851 		offset = do_div(logical_sb_block, blocksize);
3852 		bh = sb_bread_unmovable(sb, logical_sb_block);
3853 		if (!bh) {
3854 			ext4_msg(sb, KERN_ERR,
3855 			       "Can't read superblock on 2nd try");
3856 			goto failed_mount;
3857 		}
3858 		es = (struct ext4_super_block *)(bh->b_data + offset);
3859 		sbi->s_es = es;
3860 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3861 			ext4_msg(sb, KERN_ERR,
3862 			       "Magic mismatch, very weird!");
3863 			goto failed_mount;
3864 		}
3865 	}
3866 
3867 	has_huge_files = ext4_has_feature_huge_file(sb);
3868 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3869 						      has_huge_files);
3870 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3871 
3872 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3873 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3874 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3875 	} else {
3876 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3877 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3878 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3879 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3880 				 sbi->s_first_ino);
3881 			goto failed_mount;
3882 		}
3883 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3884 		    (!is_power_of_2(sbi->s_inode_size)) ||
3885 		    (sbi->s_inode_size > blocksize)) {
3886 			ext4_msg(sb, KERN_ERR,
3887 			       "unsupported inode size: %d",
3888 			       sbi->s_inode_size);
3889 			goto failed_mount;
3890 		}
3891 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3892 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3893 	}
3894 
3895 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3896 	if (ext4_has_feature_64bit(sb)) {
3897 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3898 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3899 		    !is_power_of_2(sbi->s_desc_size)) {
3900 			ext4_msg(sb, KERN_ERR,
3901 			       "unsupported descriptor size %lu",
3902 			       sbi->s_desc_size);
3903 			goto failed_mount;
3904 		}
3905 	} else
3906 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3907 
3908 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3909 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3910 
3911 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3912 	if (sbi->s_inodes_per_block == 0)
3913 		goto cantfind_ext4;
3914 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3915 	    sbi->s_inodes_per_group > blocksize * 8) {
3916 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3917 			 sbi->s_blocks_per_group);
3918 		goto failed_mount;
3919 	}
3920 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3921 					sbi->s_inodes_per_block;
3922 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3923 	sbi->s_sbh = bh;
3924 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3925 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3926 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3927 
3928 	for (i = 0; i < 4; i++)
3929 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3930 	sbi->s_def_hash_version = es->s_def_hash_version;
3931 	if (ext4_has_feature_dir_index(sb)) {
3932 		i = le32_to_cpu(es->s_flags);
3933 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3934 			sbi->s_hash_unsigned = 3;
3935 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3936 #ifdef __CHAR_UNSIGNED__
3937 			if (!sb_rdonly(sb))
3938 				es->s_flags |=
3939 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3940 			sbi->s_hash_unsigned = 3;
3941 #else
3942 			if (!sb_rdonly(sb))
3943 				es->s_flags |=
3944 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3945 #endif
3946 		}
3947 	}
3948 
3949 	/* Handle clustersize */
3950 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3951 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3952 	if (has_bigalloc) {
3953 		if (clustersize < blocksize) {
3954 			ext4_msg(sb, KERN_ERR,
3955 				 "cluster size (%d) smaller than "
3956 				 "block size (%d)", clustersize, blocksize);
3957 			goto failed_mount;
3958 		}
3959 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3960 			le32_to_cpu(es->s_log_block_size);
3961 		sbi->s_clusters_per_group =
3962 			le32_to_cpu(es->s_clusters_per_group);
3963 		if (sbi->s_clusters_per_group > blocksize * 8) {
3964 			ext4_msg(sb, KERN_ERR,
3965 				 "#clusters per group too big: %lu",
3966 				 sbi->s_clusters_per_group);
3967 			goto failed_mount;
3968 		}
3969 		if (sbi->s_blocks_per_group !=
3970 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3971 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3972 				 "clusters per group (%lu) inconsistent",
3973 				 sbi->s_blocks_per_group,
3974 				 sbi->s_clusters_per_group);
3975 			goto failed_mount;
3976 		}
3977 	} else {
3978 		if (clustersize != blocksize) {
3979 			ext4_msg(sb, KERN_ERR,
3980 				 "fragment/cluster size (%d) != "
3981 				 "block size (%d)", clustersize, blocksize);
3982 			goto failed_mount;
3983 		}
3984 		if (sbi->s_blocks_per_group > blocksize * 8) {
3985 			ext4_msg(sb, KERN_ERR,
3986 				 "#blocks per group too big: %lu",
3987 				 sbi->s_blocks_per_group);
3988 			goto failed_mount;
3989 		}
3990 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3991 		sbi->s_cluster_bits = 0;
3992 	}
3993 	sbi->s_cluster_ratio = clustersize / blocksize;
3994 
3995 	/* Do we have standard group size of clustersize * 8 blocks ? */
3996 	if (sbi->s_blocks_per_group == clustersize << 3)
3997 		set_opt2(sb, STD_GROUP_SIZE);
3998 
3999 	/*
4000 	 * Test whether we have more sectors than will fit in sector_t,
4001 	 * and whether the max offset is addressable by the page cache.
4002 	 */
4003 	err = generic_check_addressable(sb->s_blocksize_bits,
4004 					ext4_blocks_count(es));
4005 	if (err) {
4006 		ext4_msg(sb, KERN_ERR, "filesystem"
4007 			 " too large to mount safely on this system");
4008 		if (sizeof(sector_t) < 8)
4009 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
4010 		goto failed_mount;
4011 	}
4012 
4013 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4014 		goto cantfind_ext4;
4015 
4016 	/* check blocks count against device size */
4017 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4018 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4019 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4020 		       "exceeds size of device (%llu blocks)",
4021 		       ext4_blocks_count(es), blocks_count);
4022 		goto failed_mount;
4023 	}
4024 
4025 	/*
4026 	 * It makes no sense for the first data block to be beyond the end
4027 	 * of the filesystem.
4028 	 */
4029 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4030 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4031 			 "block %u is beyond end of filesystem (%llu)",
4032 			 le32_to_cpu(es->s_first_data_block),
4033 			 ext4_blocks_count(es));
4034 		goto failed_mount;
4035 	}
4036 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4037 	    (sbi->s_cluster_ratio == 1)) {
4038 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4039 			 "block is 0 with a 1k block and cluster size");
4040 		goto failed_mount;
4041 	}
4042 
4043 	blocks_count = (ext4_blocks_count(es) -
4044 			le32_to_cpu(es->s_first_data_block) +
4045 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4046 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4047 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4048 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4049 		       "(block count %llu, first data block %u, "
4050 		       "blocks per group %lu)", sbi->s_groups_count,
4051 		       ext4_blocks_count(es),
4052 		       le32_to_cpu(es->s_first_data_block),
4053 		       EXT4_BLOCKS_PER_GROUP(sb));
4054 		goto failed_mount;
4055 	}
4056 	sbi->s_groups_count = blocks_count;
4057 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4058 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4059 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4060 		   EXT4_DESC_PER_BLOCK(sb);
4061 	if (ext4_has_feature_meta_bg(sb)) {
4062 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4063 			ext4_msg(sb, KERN_WARNING,
4064 				 "first meta block group too large: %u "
4065 				 "(group descriptor block count %u)",
4066 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4067 			goto failed_mount;
4068 		}
4069 	}
4070 	sbi->s_group_desc = kvmalloc_array(db_count,
4071 					   sizeof(struct buffer_head *),
4072 					   GFP_KERNEL);
4073 	if (sbi->s_group_desc == NULL) {
4074 		ext4_msg(sb, KERN_ERR, "not enough memory");
4075 		ret = -ENOMEM;
4076 		goto failed_mount;
4077 	}
4078 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4079 	    le32_to_cpu(es->s_inodes_count)) {
4080 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4081 			 le32_to_cpu(es->s_inodes_count),
4082 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4083 		ret = -EINVAL;
4084 		goto failed_mount;
4085 	}
4086 
4087 	bgl_lock_init(sbi->s_blockgroup_lock);
4088 
4089 	/* Pre-read the descriptors into the buffer cache */
4090 	for (i = 0; i < db_count; i++) {
4091 		block = descriptor_loc(sb, logical_sb_block, i);
4092 		sb_breadahead(sb, block);
4093 	}
4094 
4095 	for (i = 0; i < db_count; i++) {
4096 		block = descriptor_loc(sb, logical_sb_block, i);
4097 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4098 		if (!sbi->s_group_desc[i]) {
4099 			ext4_msg(sb, KERN_ERR,
4100 			       "can't read group descriptor %d", i);
4101 			db_count = i;
4102 			goto failed_mount2;
4103 		}
4104 	}
4105 	sbi->s_gdb_count = db_count;
4106 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4107 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4108 		ret = -EFSCORRUPTED;
4109 		goto failed_mount2;
4110 	}
4111 
4112 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4113 
4114 	/* Register extent status tree shrinker */
4115 	if (ext4_es_register_shrinker(sbi))
4116 		goto failed_mount3;
4117 
4118 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4119 	sbi->s_extent_max_zeroout_kb = 32;
4120 
4121 	/*
4122 	 * set up enough so that it can read an inode
4123 	 */
4124 	sb->s_op = &ext4_sops;
4125 	sb->s_export_op = &ext4_export_ops;
4126 	sb->s_xattr = ext4_xattr_handlers;
4127 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4128 	sb->s_cop = &ext4_cryptops;
4129 #endif
4130 #ifdef CONFIG_QUOTA
4131 	sb->dq_op = &ext4_quota_operations;
4132 	if (ext4_has_feature_quota(sb))
4133 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4134 	else
4135 		sb->s_qcop = &ext4_qctl_operations;
4136 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4137 #endif
4138 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4139 
4140 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4141 	mutex_init(&sbi->s_orphan_lock);
4142 
4143 	sb->s_root = NULL;
4144 
4145 	needs_recovery = (es->s_last_orphan != 0 ||
4146 			  ext4_has_feature_journal_needs_recovery(sb));
4147 
4148 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4149 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4150 			goto failed_mount3a;
4151 
4152 	/*
4153 	 * The first inode we look at is the journal inode.  Don't try
4154 	 * root first: it may be modified in the journal!
4155 	 */
4156 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4157 		err = ext4_load_journal(sb, es, journal_devnum);
4158 		if (err)
4159 			goto failed_mount3a;
4160 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4161 		   ext4_has_feature_journal_needs_recovery(sb)) {
4162 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4163 		       "suppressed and not mounted read-only");
4164 		goto failed_mount_wq;
4165 	} else {
4166 		/* Nojournal mode, all journal mount options are illegal */
4167 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4168 			ext4_msg(sb, KERN_ERR, "can't mount with "
4169 				 "journal_checksum, fs mounted w/o journal");
4170 			goto failed_mount_wq;
4171 		}
4172 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4173 			ext4_msg(sb, KERN_ERR, "can't mount with "
4174 				 "journal_async_commit, fs mounted w/o journal");
4175 			goto failed_mount_wq;
4176 		}
4177 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4178 			ext4_msg(sb, KERN_ERR, "can't mount with "
4179 				 "commit=%lu, fs mounted w/o journal",
4180 				 sbi->s_commit_interval / HZ);
4181 			goto failed_mount_wq;
4182 		}
4183 		if (EXT4_MOUNT_DATA_FLAGS &
4184 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4185 			ext4_msg(sb, KERN_ERR, "can't mount with "
4186 				 "data=, fs mounted w/o journal");
4187 			goto failed_mount_wq;
4188 		}
4189 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4190 		clear_opt(sb, JOURNAL_CHECKSUM);
4191 		clear_opt(sb, DATA_FLAGS);
4192 		sbi->s_journal = NULL;
4193 		needs_recovery = 0;
4194 		goto no_journal;
4195 	}
4196 
4197 	if (ext4_has_feature_64bit(sb) &&
4198 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4199 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4200 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4201 		goto failed_mount_wq;
4202 	}
4203 
4204 	if (!set_journal_csum_feature_set(sb)) {
4205 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4206 			 "feature set");
4207 		goto failed_mount_wq;
4208 	}
4209 
4210 	/* We have now updated the journal if required, so we can
4211 	 * validate the data journaling mode. */
4212 	switch (test_opt(sb, DATA_FLAGS)) {
4213 	case 0:
4214 		/* No mode set, assume a default based on the journal
4215 		 * capabilities: ORDERED_DATA if the journal can
4216 		 * cope, else JOURNAL_DATA
4217 		 */
4218 		if (jbd2_journal_check_available_features
4219 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4220 			set_opt(sb, ORDERED_DATA);
4221 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4222 		} else {
4223 			set_opt(sb, JOURNAL_DATA);
4224 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4225 		}
4226 		break;
4227 
4228 	case EXT4_MOUNT_ORDERED_DATA:
4229 	case EXT4_MOUNT_WRITEBACK_DATA:
4230 		if (!jbd2_journal_check_available_features
4231 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4232 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4233 			       "requested data journaling mode");
4234 			goto failed_mount_wq;
4235 		}
4236 	default:
4237 		break;
4238 	}
4239 
4240 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4241 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4242 		ext4_msg(sb, KERN_ERR, "can't mount with "
4243 			"journal_async_commit in data=ordered mode");
4244 		goto failed_mount_wq;
4245 	}
4246 
4247 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4248 
4249 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4250 
4251 no_journal:
4252 	if (!test_opt(sb, NO_MBCACHE)) {
4253 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4254 		if (!sbi->s_ea_block_cache) {
4255 			ext4_msg(sb, KERN_ERR,
4256 				 "Failed to create ea_block_cache");
4257 			goto failed_mount_wq;
4258 		}
4259 
4260 		if (ext4_has_feature_ea_inode(sb)) {
4261 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4262 			if (!sbi->s_ea_inode_cache) {
4263 				ext4_msg(sb, KERN_ERR,
4264 					 "Failed to create ea_inode_cache");
4265 				goto failed_mount_wq;
4266 			}
4267 		}
4268 	}
4269 
4270 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4271 	    (blocksize != PAGE_SIZE)) {
4272 		ext4_msg(sb, KERN_ERR,
4273 			 "Unsupported blocksize for fs encryption");
4274 		goto failed_mount_wq;
4275 	}
4276 
4277 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4278 	    !ext4_has_feature_encrypt(sb)) {
4279 		ext4_set_feature_encrypt(sb);
4280 		ext4_commit_super(sb, 1);
4281 	}
4282 
4283 	/*
4284 	 * Get the # of file system overhead blocks from the
4285 	 * superblock if present.
4286 	 */
4287 	if (es->s_overhead_clusters)
4288 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4289 	else {
4290 		err = ext4_calculate_overhead(sb);
4291 		if (err)
4292 			goto failed_mount_wq;
4293 	}
4294 
4295 	/*
4296 	 * The maximum number of concurrent works can be high and
4297 	 * concurrency isn't really necessary.  Limit it to 1.
4298 	 */
4299 	EXT4_SB(sb)->rsv_conversion_wq =
4300 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4301 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4302 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4303 		ret = -ENOMEM;
4304 		goto failed_mount4;
4305 	}
4306 
4307 	/*
4308 	 * The jbd2_journal_load will have done any necessary log recovery,
4309 	 * so we can safely mount the rest of the filesystem now.
4310 	 */
4311 
4312 	root = ext4_iget(sb, EXT4_ROOT_INO);
4313 	if (IS_ERR(root)) {
4314 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4315 		ret = PTR_ERR(root);
4316 		root = NULL;
4317 		goto failed_mount4;
4318 	}
4319 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4320 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4321 		iput(root);
4322 		goto failed_mount4;
4323 	}
4324 	sb->s_root = d_make_root(root);
4325 	if (!sb->s_root) {
4326 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4327 		ret = -ENOMEM;
4328 		goto failed_mount4;
4329 	}
4330 
4331 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4332 	if (ret == -EROFS) {
4333 		sb->s_flags |= SB_RDONLY;
4334 		ret = 0;
4335 	} else if (ret)
4336 		goto failed_mount4a;
4337 
4338 	/* determine the minimum size of new large inodes, if present */
4339 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4340 	    sbi->s_want_extra_isize == 0) {
4341 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4342 						     EXT4_GOOD_OLD_INODE_SIZE;
4343 		if (ext4_has_feature_extra_isize(sb)) {
4344 			if (sbi->s_want_extra_isize <
4345 			    le16_to_cpu(es->s_want_extra_isize))
4346 				sbi->s_want_extra_isize =
4347 					le16_to_cpu(es->s_want_extra_isize);
4348 			if (sbi->s_want_extra_isize <
4349 			    le16_to_cpu(es->s_min_extra_isize))
4350 				sbi->s_want_extra_isize =
4351 					le16_to_cpu(es->s_min_extra_isize);
4352 		}
4353 	}
4354 	/* Check if enough inode space is available */
4355 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4356 							sbi->s_inode_size) {
4357 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4358 						       EXT4_GOOD_OLD_INODE_SIZE;
4359 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4360 			 "available");
4361 	}
4362 
4363 	ext4_set_resv_clusters(sb);
4364 
4365 	err = ext4_setup_system_zone(sb);
4366 	if (err) {
4367 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4368 			 "zone (%d)", err);
4369 		goto failed_mount4a;
4370 	}
4371 
4372 	ext4_ext_init(sb);
4373 	err = ext4_mb_init(sb);
4374 	if (err) {
4375 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4376 			 err);
4377 		goto failed_mount5;
4378 	}
4379 
4380 	block = ext4_count_free_clusters(sb);
4381 	ext4_free_blocks_count_set(sbi->s_es,
4382 				   EXT4_C2B(sbi, block));
4383 	ext4_superblock_csum_set(sb);
4384 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4385 				  GFP_KERNEL);
4386 	if (!err) {
4387 		unsigned long freei = ext4_count_free_inodes(sb);
4388 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4389 		ext4_superblock_csum_set(sb);
4390 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4391 					  GFP_KERNEL);
4392 	}
4393 	if (!err)
4394 		err = percpu_counter_init(&sbi->s_dirs_counter,
4395 					  ext4_count_dirs(sb), GFP_KERNEL);
4396 	if (!err)
4397 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4398 					  GFP_KERNEL);
4399 	if (!err)
4400 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4401 
4402 	if (err) {
4403 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4404 		goto failed_mount6;
4405 	}
4406 
4407 	if (ext4_has_feature_flex_bg(sb))
4408 		if (!ext4_fill_flex_info(sb)) {
4409 			ext4_msg(sb, KERN_ERR,
4410 			       "unable to initialize "
4411 			       "flex_bg meta info!");
4412 			goto failed_mount6;
4413 		}
4414 
4415 	err = ext4_register_li_request(sb, first_not_zeroed);
4416 	if (err)
4417 		goto failed_mount6;
4418 
4419 	err = ext4_register_sysfs(sb);
4420 	if (err)
4421 		goto failed_mount7;
4422 
4423 #ifdef CONFIG_QUOTA
4424 	/* Enable quota usage during mount. */
4425 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4426 		err = ext4_enable_quotas(sb);
4427 		if (err)
4428 			goto failed_mount8;
4429 	}
4430 #endif  /* CONFIG_QUOTA */
4431 
4432 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4433 	ext4_orphan_cleanup(sb, es);
4434 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4435 	if (needs_recovery) {
4436 		ext4_msg(sb, KERN_INFO, "recovery complete");
4437 		ext4_mark_recovery_complete(sb, es);
4438 	}
4439 	if (EXT4_SB(sb)->s_journal) {
4440 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4441 			descr = " journalled data mode";
4442 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4443 			descr = " ordered data mode";
4444 		else
4445 			descr = " writeback data mode";
4446 	} else
4447 		descr = "out journal";
4448 
4449 	if (test_opt(sb, DISCARD)) {
4450 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4451 		if (!blk_queue_discard(q))
4452 			ext4_msg(sb, KERN_WARNING,
4453 				 "mounting with \"discard\" option, but "
4454 				 "the device does not support discard");
4455 	}
4456 
4457 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4458 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4459 			 "Opts: %.*s%s%s", descr,
4460 			 (int) sizeof(sbi->s_es->s_mount_opts),
4461 			 sbi->s_es->s_mount_opts,
4462 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4463 
4464 	if (es->s_error_count)
4465 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4466 
4467 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4468 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4469 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4470 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4471 
4472 	kfree(orig_data);
4473 	return 0;
4474 
4475 cantfind_ext4:
4476 	if (!silent)
4477 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4478 	goto failed_mount;
4479 
4480 #ifdef CONFIG_QUOTA
4481 failed_mount8:
4482 	ext4_unregister_sysfs(sb);
4483 #endif
4484 failed_mount7:
4485 	ext4_unregister_li_request(sb);
4486 failed_mount6:
4487 	ext4_mb_release(sb);
4488 	if (sbi->s_flex_groups)
4489 		kvfree(sbi->s_flex_groups);
4490 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4491 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4492 	percpu_counter_destroy(&sbi->s_dirs_counter);
4493 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4494 failed_mount5:
4495 	ext4_ext_release(sb);
4496 	ext4_release_system_zone(sb);
4497 failed_mount4a:
4498 	dput(sb->s_root);
4499 	sb->s_root = NULL;
4500 failed_mount4:
4501 	ext4_msg(sb, KERN_ERR, "mount failed");
4502 	if (EXT4_SB(sb)->rsv_conversion_wq)
4503 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4504 failed_mount_wq:
4505 	if (sbi->s_ea_inode_cache) {
4506 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4507 		sbi->s_ea_inode_cache = NULL;
4508 	}
4509 	if (sbi->s_ea_block_cache) {
4510 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4511 		sbi->s_ea_block_cache = NULL;
4512 	}
4513 	if (sbi->s_journal) {
4514 		jbd2_journal_destroy(sbi->s_journal);
4515 		sbi->s_journal = NULL;
4516 	}
4517 failed_mount3a:
4518 	ext4_es_unregister_shrinker(sbi);
4519 failed_mount3:
4520 	del_timer_sync(&sbi->s_err_report);
4521 	if (sbi->s_mmp_tsk)
4522 		kthread_stop(sbi->s_mmp_tsk);
4523 failed_mount2:
4524 	for (i = 0; i < db_count; i++)
4525 		brelse(sbi->s_group_desc[i]);
4526 	kvfree(sbi->s_group_desc);
4527 failed_mount:
4528 	if (sbi->s_chksum_driver)
4529 		crypto_free_shash(sbi->s_chksum_driver);
4530 #ifdef CONFIG_QUOTA
4531 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4532 		kfree(sbi->s_qf_names[i]);
4533 #endif
4534 	ext4_blkdev_remove(sbi);
4535 	brelse(bh);
4536 out_fail:
4537 	sb->s_fs_info = NULL;
4538 	kfree(sbi->s_blockgroup_lock);
4539 out_free_base:
4540 	kfree(sbi);
4541 	kfree(orig_data);
4542 	fs_put_dax(dax_dev);
4543 	return err ? err : ret;
4544 }
4545 
4546 /*
4547  * Setup any per-fs journal parameters now.  We'll do this both on
4548  * initial mount, once the journal has been initialised but before we've
4549  * done any recovery; and again on any subsequent remount.
4550  */
4551 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4552 {
4553 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4554 
4555 	journal->j_commit_interval = sbi->s_commit_interval;
4556 	journal->j_min_batch_time = sbi->s_min_batch_time;
4557 	journal->j_max_batch_time = sbi->s_max_batch_time;
4558 
4559 	write_lock(&journal->j_state_lock);
4560 	if (test_opt(sb, BARRIER))
4561 		journal->j_flags |= JBD2_BARRIER;
4562 	else
4563 		journal->j_flags &= ~JBD2_BARRIER;
4564 	if (test_opt(sb, DATA_ERR_ABORT))
4565 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4566 	else
4567 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4568 	write_unlock(&journal->j_state_lock);
4569 }
4570 
4571 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4572 					     unsigned int journal_inum)
4573 {
4574 	struct inode *journal_inode;
4575 
4576 	/*
4577 	 * Test for the existence of a valid inode on disk.  Bad things
4578 	 * happen if we iget() an unused inode, as the subsequent iput()
4579 	 * will try to delete it.
4580 	 */
4581 	journal_inode = ext4_iget(sb, journal_inum);
4582 	if (IS_ERR(journal_inode)) {
4583 		ext4_msg(sb, KERN_ERR, "no journal found");
4584 		return NULL;
4585 	}
4586 	if (!journal_inode->i_nlink) {
4587 		make_bad_inode(journal_inode);
4588 		iput(journal_inode);
4589 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4590 		return NULL;
4591 	}
4592 
4593 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4594 		  journal_inode, journal_inode->i_size);
4595 	if (!S_ISREG(journal_inode->i_mode)) {
4596 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4597 		iput(journal_inode);
4598 		return NULL;
4599 	}
4600 	return journal_inode;
4601 }
4602 
4603 static journal_t *ext4_get_journal(struct super_block *sb,
4604 				   unsigned int journal_inum)
4605 {
4606 	struct inode *journal_inode;
4607 	journal_t *journal;
4608 
4609 	BUG_ON(!ext4_has_feature_journal(sb));
4610 
4611 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4612 	if (!journal_inode)
4613 		return NULL;
4614 
4615 	journal = jbd2_journal_init_inode(journal_inode);
4616 	if (!journal) {
4617 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4618 		iput(journal_inode);
4619 		return NULL;
4620 	}
4621 	journal->j_private = sb;
4622 	ext4_init_journal_params(sb, journal);
4623 	return journal;
4624 }
4625 
4626 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4627 				       dev_t j_dev)
4628 {
4629 	struct buffer_head *bh;
4630 	journal_t *journal;
4631 	ext4_fsblk_t start;
4632 	ext4_fsblk_t len;
4633 	int hblock, blocksize;
4634 	ext4_fsblk_t sb_block;
4635 	unsigned long offset;
4636 	struct ext4_super_block *es;
4637 	struct block_device *bdev;
4638 
4639 	BUG_ON(!ext4_has_feature_journal(sb));
4640 
4641 	bdev = ext4_blkdev_get(j_dev, sb);
4642 	if (bdev == NULL)
4643 		return NULL;
4644 
4645 	blocksize = sb->s_blocksize;
4646 	hblock = bdev_logical_block_size(bdev);
4647 	if (blocksize < hblock) {
4648 		ext4_msg(sb, KERN_ERR,
4649 			"blocksize too small for journal device");
4650 		goto out_bdev;
4651 	}
4652 
4653 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4654 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4655 	set_blocksize(bdev, blocksize);
4656 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4657 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4658 		       "external journal");
4659 		goto out_bdev;
4660 	}
4661 
4662 	es = (struct ext4_super_block *) (bh->b_data + offset);
4663 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4664 	    !(le32_to_cpu(es->s_feature_incompat) &
4665 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4666 		ext4_msg(sb, KERN_ERR, "external journal has "
4667 					"bad superblock");
4668 		brelse(bh);
4669 		goto out_bdev;
4670 	}
4671 
4672 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4673 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4674 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4675 		ext4_msg(sb, KERN_ERR, "external journal has "
4676 				       "corrupt superblock");
4677 		brelse(bh);
4678 		goto out_bdev;
4679 	}
4680 
4681 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4682 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4683 		brelse(bh);
4684 		goto out_bdev;
4685 	}
4686 
4687 	len = ext4_blocks_count(es);
4688 	start = sb_block + 1;
4689 	brelse(bh);	/* we're done with the superblock */
4690 
4691 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4692 					start, len, blocksize);
4693 	if (!journal) {
4694 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4695 		goto out_bdev;
4696 	}
4697 	journal->j_private = sb;
4698 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4699 	wait_on_buffer(journal->j_sb_buffer);
4700 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4701 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4702 		goto out_journal;
4703 	}
4704 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4705 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4706 					"user (unsupported) - %d",
4707 			be32_to_cpu(journal->j_superblock->s_nr_users));
4708 		goto out_journal;
4709 	}
4710 	EXT4_SB(sb)->journal_bdev = bdev;
4711 	ext4_init_journal_params(sb, journal);
4712 	return journal;
4713 
4714 out_journal:
4715 	jbd2_journal_destroy(journal);
4716 out_bdev:
4717 	ext4_blkdev_put(bdev);
4718 	return NULL;
4719 }
4720 
4721 static int ext4_load_journal(struct super_block *sb,
4722 			     struct ext4_super_block *es,
4723 			     unsigned long journal_devnum)
4724 {
4725 	journal_t *journal;
4726 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4727 	dev_t journal_dev;
4728 	int err = 0;
4729 	int really_read_only;
4730 
4731 	BUG_ON(!ext4_has_feature_journal(sb));
4732 
4733 	if (journal_devnum &&
4734 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4735 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4736 			"numbers have changed");
4737 		journal_dev = new_decode_dev(journal_devnum);
4738 	} else
4739 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4740 
4741 	really_read_only = bdev_read_only(sb->s_bdev);
4742 
4743 	/*
4744 	 * Are we loading a blank journal or performing recovery after a
4745 	 * crash?  For recovery, we need to check in advance whether we
4746 	 * can get read-write access to the device.
4747 	 */
4748 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4749 		if (sb_rdonly(sb)) {
4750 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4751 					"required on readonly filesystem");
4752 			if (really_read_only) {
4753 				ext4_msg(sb, KERN_ERR, "write access "
4754 					"unavailable, cannot proceed "
4755 					"(try mounting with noload)");
4756 				return -EROFS;
4757 			}
4758 			ext4_msg(sb, KERN_INFO, "write access will "
4759 			       "be enabled during recovery");
4760 		}
4761 	}
4762 
4763 	if (journal_inum && journal_dev) {
4764 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4765 		       "and inode journals!");
4766 		return -EINVAL;
4767 	}
4768 
4769 	if (journal_inum) {
4770 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4771 			return -EINVAL;
4772 	} else {
4773 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4774 			return -EINVAL;
4775 	}
4776 
4777 	if (!(journal->j_flags & JBD2_BARRIER))
4778 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4779 
4780 	if (!ext4_has_feature_journal_needs_recovery(sb))
4781 		err = jbd2_journal_wipe(journal, !really_read_only);
4782 	if (!err) {
4783 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4784 		if (save)
4785 			memcpy(save, ((char *) es) +
4786 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4787 		err = jbd2_journal_load(journal);
4788 		if (save)
4789 			memcpy(((char *) es) + EXT4_S_ERR_START,
4790 			       save, EXT4_S_ERR_LEN);
4791 		kfree(save);
4792 	}
4793 
4794 	if (err) {
4795 		ext4_msg(sb, KERN_ERR, "error loading journal");
4796 		jbd2_journal_destroy(journal);
4797 		return err;
4798 	}
4799 
4800 	EXT4_SB(sb)->s_journal = journal;
4801 	ext4_clear_journal_err(sb, es);
4802 
4803 	if (!really_read_only && journal_devnum &&
4804 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4805 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4806 
4807 		/* Make sure we flush the recovery flag to disk. */
4808 		ext4_commit_super(sb, 1);
4809 	}
4810 
4811 	return 0;
4812 }
4813 
4814 static int ext4_commit_super(struct super_block *sb, int sync)
4815 {
4816 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4817 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4818 	int error = 0;
4819 
4820 	if (!sbh || block_device_ejected(sb))
4821 		return error;
4822 
4823 	/*
4824 	 * The superblock bh should be mapped, but it might not be if the
4825 	 * device was hot-removed. Not much we can do but fail the I/O.
4826 	 */
4827 	if (!buffer_mapped(sbh))
4828 		return error;
4829 
4830 	/*
4831 	 * If the file system is mounted read-only, don't update the
4832 	 * superblock write time.  This avoids updating the superblock
4833 	 * write time when we are mounting the root file system
4834 	 * read/only but we need to replay the journal; at that point,
4835 	 * for people who are east of GMT and who make their clock
4836 	 * tick in localtime for Windows bug-for-bug compatibility,
4837 	 * the clock is set in the future, and this will cause e2fsck
4838 	 * to complain and force a full file system check.
4839 	 */
4840 	if (!(sb->s_flags & SB_RDONLY))
4841 		ext4_update_tstamp(es, s_wtime);
4842 	if (sb->s_bdev->bd_part)
4843 		es->s_kbytes_written =
4844 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4845 			    ((part_stat_read(sb->s_bdev->bd_part,
4846 					     sectors[STAT_WRITE]) -
4847 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4848 	else
4849 		es->s_kbytes_written =
4850 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4851 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4852 		ext4_free_blocks_count_set(es,
4853 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4854 				&EXT4_SB(sb)->s_freeclusters_counter)));
4855 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4856 		es->s_free_inodes_count =
4857 			cpu_to_le32(percpu_counter_sum_positive(
4858 				&EXT4_SB(sb)->s_freeinodes_counter));
4859 	BUFFER_TRACE(sbh, "marking dirty");
4860 	ext4_superblock_csum_set(sb);
4861 	if (sync)
4862 		lock_buffer(sbh);
4863 	if (buffer_write_io_error(sbh)) {
4864 		/*
4865 		 * Oh, dear.  A previous attempt to write the
4866 		 * superblock failed.  This could happen because the
4867 		 * USB device was yanked out.  Or it could happen to
4868 		 * be a transient write error and maybe the block will
4869 		 * be remapped.  Nothing we can do but to retry the
4870 		 * write and hope for the best.
4871 		 */
4872 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4873 		       "superblock detected");
4874 		clear_buffer_write_io_error(sbh);
4875 		set_buffer_uptodate(sbh);
4876 	}
4877 	mark_buffer_dirty(sbh);
4878 	if (sync) {
4879 		unlock_buffer(sbh);
4880 		error = __sync_dirty_buffer(sbh,
4881 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4882 		if (buffer_write_io_error(sbh)) {
4883 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4884 			       "superblock");
4885 			clear_buffer_write_io_error(sbh);
4886 			set_buffer_uptodate(sbh);
4887 		}
4888 	}
4889 	return error;
4890 }
4891 
4892 /*
4893  * Have we just finished recovery?  If so, and if we are mounting (or
4894  * remounting) the filesystem readonly, then we will end up with a
4895  * consistent fs on disk.  Record that fact.
4896  */
4897 static void ext4_mark_recovery_complete(struct super_block *sb,
4898 					struct ext4_super_block *es)
4899 {
4900 	journal_t *journal = EXT4_SB(sb)->s_journal;
4901 
4902 	if (!ext4_has_feature_journal(sb)) {
4903 		BUG_ON(journal != NULL);
4904 		return;
4905 	}
4906 	jbd2_journal_lock_updates(journal);
4907 	if (jbd2_journal_flush(journal) < 0)
4908 		goto out;
4909 
4910 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
4911 		ext4_clear_feature_journal_needs_recovery(sb);
4912 		ext4_commit_super(sb, 1);
4913 	}
4914 
4915 out:
4916 	jbd2_journal_unlock_updates(journal);
4917 }
4918 
4919 /*
4920  * If we are mounting (or read-write remounting) a filesystem whose journal
4921  * has recorded an error from a previous lifetime, move that error to the
4922  * main filesystem now.
4923  */
4924 static void ext4_clear_journal_err(struct super_block *sb,
4925 				   struct ext4_super_block *es)
4926 {
4927 	journal_t *journal;
4928 	int j_errno;
4929 	const char *errstr;
4930 
4931 	BUG_ON(!ext4_has_feature_journal(sb));
4932 
4933 	journal = EXT4_SB(sb)->s_journal;
4934 
4935 	/*
4936 	 * Now check for any error status which may have been recorded in the
4937 	 * journal by a prior ext4_error() or ext4_abort()
4938 	 */
4939 
4940 	j_errno = jbd2_journal_errno(journal);
4941 	if (j_errno) {
4942 		char nbuf[16];
4943 
4944 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4945 		ext4_warning(sb, "Filesystem error recorded "
4946 			     "from previous mount: %s", errstr);
4947 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4948 
4949 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4950 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4951 		ext4_commit_super(sb, 1);
4952 
4953 		jbd2_journal_clear_err(journal);
4954 		jbd2_journal_update_sb_errno(journal);
4955 	}
4956 }
4957 
4958 /*
4959  * Force the running and committing transactions to commit,
4960  * and wait on the commit.
4961  */
4962 int ext4_force_commit(struct super_block *sb)
4963 {
4964 	journal_t *journal;
4965 
4966 	if (sb_rdonly(sb))
4967 		return 0;
4968 
4969 	journal = EXT4_SB(sb)->s_journal;
4970 	return ext4_journal_force_commit(journal);
4971 }
4972 
4973 static int ext4_sync_fs(struct super_block *sb, int wait)
4974 {
4975 	int ret = 0;
4976 	tid_t target;
4977 	bool needs_barrier = false;
4978 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4979 
4980 	if (unlikely(ext4_forced_shutdown(sbi)))
4981 		return 0;
4982 
4983 	trace_ext4_sync_fs(sb, wait);
4984 	flush_workqueue(sbi->rsv_conversion_wq);
4985 	/*
4986 	 * Writeback quota in non-journalled quota case - journalled quota has
4987 	 * no dirty dquots
4988 	 */
4989 	dquot_writeback_dquots(sb, -1);
4990 	/*
4991 	 * Data writeback is possible w/o journal transaction, so barrier must
4992 	 * being sent at the end of the function. But we can skip it if
4993 	 * transaction_commit will do it for us.
4994 	 */
4995 	if (sbi->s_journal) {
4996 		target = jbd2_get_latest_transaction(sbi->s_journal);
4997 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4998 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4999 			needs_barrier = true;
5000 
5001 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5002 			if (wait)
5003 				ret = jbd2_log_wait_commit(sbi->s_journal,
5004 							   target);
5005 		}
5006 	} else if (wait && test_opt(sb, BARRIER))
5007 		needs_barrier = true;
5008 	if (needs_barrier) {
5009 		int err;
5010 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5011 		if (!ret)
5012 			ret = err;
5013 	}
5014 
5015 	return ret;
5016 }
5017 
5018 /*
5019  * LVM calls this function before a (read-only) snapshot is created.  This
5020  * gives us a chance to flush the journal completely and mark the fs clean.
5021  *
5022  * Note that only this function cannot bring a filesystem to be in a clean
5023  * state independently. It relies on upper layer to stop all data & metadata
5024  * modifications.
5025  */
5026 static int ext4_freeze(struct super_block *sb)
5027 {
5028 	int error = 0;
5029 	journal_t *journal;
5030 
5031 	if (sb_rdonly(sb))
5032 		return 0;
5033 
5034 	journal = EXT4_SB(sb)->s_journal;
5035 
5036 	if (journal) {
5037 		/* Now we set up the journal barrier. */
5038 		jbd2_journal_lock_updates(journal);
5039 
5040 		/*
5041 		 * Don't clear the needs_recovery flag if we failed to
5042 		 * flush the journal.
5043 		 */
5044 		error = jbd2_journal_flush(journal);
5045 		if (error < 0)
5046 			goto out;
5047 
5048 		/* Journal blocked and flushed, clear needs_recovery flag. */
5049 		ext4_clear_feature_journal_needs_recovery(sb);
5050 	}
5051 
5052 	error = ext4_commit_super(sb, 1);
5053 out:
5054 	if (journal)
5055 		/* we rely on upper layer to stop further updates */
5056 		jbd2_journal_unlock_updates(journal);
5057 	return error;
5058 }
5059 
5060 /*
5061  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5062  * flag here, even though the filesystem is not technically dirty yet.
5063  */
5064 static int ext4_unfreeze(struct super_block *sb)
5065 {
5066 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5067 		return 0;
5068 
5069 	if (EXT4_SB(sb)->s_journal) {
5070 		/* Reset the needs_recovery flag before the fs is unlocked. */
5071 		ext4_set_feature_journal_needs_recovery(sb);
5072 	}
5073 
5074 	ext4_commit_super(sb, 1);
5075 	return 0;
5076 }
5077 
5078 /*
5079  * Structure to save mount options for ext4_remount's benefit
5080  */
5081 struct ext4_mount_options {
5082 	unsigned long s_mount_opt;
5083 	unsigned long s_mount_opt2;
5084 	kuid_t s_resuid;
5085 	kgid_t s_resgid;
5086 	unsigned long s_commit_interval;
5087 	u32 s_min_batch_time, s_max_batch_time;
5088 #ifdef CONFIG_QUOTA
5089 	int s_jquota_fmt;
5090 	char *s_qf_names[EXT4_MAXQUOTAS];
5091 #endif
5092 };
5093 
5094 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5095 {
5096 	struct ext4_super_block *es;
5097 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5098 	unsigned long old_sb_flags;
5099 	struct ext4_mount_options old_opts;
5100 	int enable_quota = 0;
5101 	ext4_group_t g;
5102 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5103 	int err = 0;
5104 #ifdef CONFIG_QUOTA
5105 	int i, j;
5106 #endif
5107 	char *orig_data = kstrdup(data, GFP_KERNEL);
5108 
5109 	if (data && !orig_data)
5110 		return -ENOMEM;
5111 
5112 	/* Store the original options */
5113 	old_sb_flags = sb->s_flags;
5114 	old_opts.s_mount_opt = sbi->s_mount_opt;
5115 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5116 	old_opts.s_resuid = sbi->s_resuid;
5117 	old_opts.s_resgid = sbi->s_resgid;
5118 	old_opts.s_commit_interval = sbi->s_commit_interval;
5119 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5120 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5121 #ifdef CONFIG_QUOTA
5122 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5123 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5124 		if (sbi->s_qf_names[i]) {
5125 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
5126 							 GFP_KERNEL);
5127 			if (!old_opts.s_qf_names[i]) {
5128 				for (j = 0; j < i; j++)
5129 					kfree(old_opts.s_qf_names[j]);
5130 				kfree(orig_data);
5131 				return -ENOMEM;
5132 			}
5133 		} else
5134 			old_opts.s_qf_names[i] = NULL;
5135 #endif
5136 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5137 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5138 
5139 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5140 		err = -EINVAL;
5141 		goto restore_opts;
5142 	}
5143 
5144 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5145 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5146 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5147 			 "during remount not supported; ignoring");
5148 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5149 	}
5150 
5151 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5152 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5153 			ext4_msg(sb, KERN_ERR, "can't mount with "
5154 				 "both data=journal and delalloc");
5155 			err = -EINVAL;
5156 			goto restore_opts;
5157 		}
5158 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5159 			ext4_msg(sb, KERN_ERR, "can't mount with "
5160 				 "both data=journal and dioread_nolock");
5161 			err = -EINVAL;
5162 			goto restore_opts;
5163 		}
5164 		if (test_opt(sb, DAX)) {
5165 			ext4_msg(sb, KERN_ERR, "can't mount with "
5166 				 "both data=journal and dax");
5167 			err = -EINVAL;
5168 			goto restore_opts;
5169 		}
5170 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5171 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5172 			ext4_msg(sb, KERN_ERR, "can't mount with "
5173 				"journal_async_commit in data=ordered mode");
5174 			err = -EINVAL;
5175 			goto restore_opts;
5176 		}
5177 	}
5178 
5179 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5180 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5181 		err = -EINVAL;
5182 		goto restore_opts;
5183 	}
5184 
5185 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5186 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5187 			"dax flag with busy inodes while remounting");
5188 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5189 	}
5190 
5191 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5192 		ext4_abort(sb, "Abort forced by user");
5193 
5194 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5195 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5196 
5197 	es = sbi->s_es;
5198 
5199 	if (sbi->s_journal) {
5200 		ext4_init_journal_params(sb, sbi->s_journal);
5201 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5202 	}
5203 
5204 	if (*flags & SB_LAZYTIME)
5205 		sb->s_flags |= SB_LAZYTIME;
5206 
5207 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5208 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5209 			err = -EROFS;
5210 			goto restore_opts;
5211 		}
5212 
5213 		if (*flags & SB_RDONLY) {
5214 			err = sync_filesystem(sb);
5215 			if (err < 0)
5216 				goto restore_opts;
5217 			err = dquot_suspend(sb, -1);
5218 			if (err < 0)
5219 				goto restore_opts;
5220 
5221 			/*
5222 			 * First of all, the unconditional stuff we have to do
5223 			 * to disable replay of the journal when we next remount
5224 			 */
5225 			sb->s_flags |= SB_RDONLY;
5226 
5227 			/*
5228 			 * OK, test if we are remounting a valid rw partition
5229 			 * readonly, and if so set the rdonly flag and then
5230 			 * mark the partition as valid again.
5231 			 */
5232 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5233 			    (sbi->s_mount_state & EXT4_VALID_FS))
5234 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5235 
5236 			if (sbi->s_journal)
5237 				ext4_mark_recovery_complete(sb, es);
5238 			if (sbi->s_mmp_tsk)
5239 				kthread_stop(sbi->s_mmp_tsk);
5240 		} else {
5241 			/* Make sure we can mount this feature set readwrite */
5242 			if (ext4_has_feature_readonly(sb) ||
5243 			    !ext4_feature_set_ok(sb, 0)) {
5244 				err = -EROFS;
5245 				goto restore_opts;
5246 			}
5247 			/*
5248 			 * Make sure the group descriptor checksums
5249 			 * are sane.  If they aren't, refuse to remount r/w.
5250 			 */
5251 			for (g = 0; g < sbi->s_groups_count; g++) {
5252 				struct ext4_group_desc *gdp =
5253 					ext4_get_group_desc(sb, g, NULL);
5254 
5255 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5256 					ext4_msg(sb, KERN_ERR,
5257 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5258 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5259 					       le16_to_cpu(gdp->bg_checksum));
5260 					err = -EFSBADCRC;
5261 					goto restore_opts;
5262 				}
5263 			}
5264 
5265 			/*
5266 			 * If we have an unprocessed orphan list hanging
5267 			 * around from a previously readonly bdev mount,
5268 			 * require a full umount/remount for now.
5269 			 */
5270 			if (es->s_last_orphan) {
5271 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5272 				       "remount RDWR because of unprocessed "
5273 				       "orphan inode list.  Please "
5274 				       "umount/remount instead");
5275 				err = -EINVAL;
5276 				goto restore_opts;
5277 			}
5278 
5279 			/*
5280 			 * Mounting a RDONLY partition read-write, so reread
5281 			 * and store the current valid flag.  (It may have
5282 			 * been changed by e2fsck since we originally mounted
5283 			 * the partition.)
5284 			 */
5285 			if (sbi->s_journal)
5286 				ext4_clear_journal_err(sb, es);
5287 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5288 
5289 			err = ext4_setup_super(sb, es, 0);
5290 			if (err)
5291 				goto restore_opts;
5292 
5293 			sb->s_flags &= ~SB_RDONLY;
5294 			if (ext4_has_feature_mmp(sb))
5295 				if (ext4_multi_mount_protect(sb,
5296 						le64_to_cpu(es->s_mmp_block))) {
5297 					err = -EROFS;
5298 					goto restore_opts;
5299 				}
5300 			enable_quota = 1;
5301 		}
5302 	}
5303 
5304 	/*
5305 	 * Reinitialize lazy itable initialization thread based on
5306 	 * current settings
5307 	 */
5308 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5309 		ext4_unregister_li_request(sb);
5310 	else {
5311 		ext4_group_t first_not_zeroed;
5312 		first_not_zeroed = ext4_has_uninit_itable(sb);
5313 		ext4_register_li_request(sb, first_not_zeroed);
5314 	}
5315 
5316 	ext4_setup_system_zone(sb);
5317 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5318 		err = ext4_commit_super(sb, 1);
5319 		if (err)
5320 			goto restore_opts;
5321 	}
5322 
5323 #ifdef CONFIG_QUOTA
5324 	/* Release old quota file names */
5325 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5326 		kfree(old_opts.s_qf_names[i]);
5327 	if (enable_quota) {
5328 		if (sb_any_quota_suspended(sb))
5329 			dquot_resume(sb, -1);
5330 		else if (ext4_has_feature_quota(sb)) {
5331 			err = ext4_enable_quotas(sb);
5332 			if (err)
5333 				goto restore_opts;
5334 		}
5335 	}
5336 #endif
5337 
5338 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5339 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5340 	kfree(orig_data);
5341 	return 0;
5342 
5343 restore_opts:
5344 	sb->s_flags = old_sb_flags;
5345 	sbi->s_mount_opt = old_opts.s_mount_opt;
5346 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5347 	sbi->s_resuid = old_opts.s_resuid;
5348 	sbi->s_resgid = old_opts.s_resgid;
5349 	sbi->s_commit_interval = old_opts.s_commit_interval;
5350 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5351 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5352 #ifdef CONFIG_QUOTA
5353 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5354 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5355 		kfree(sbi->s_qf_names[i]);
5356 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5357 	}
5358 #endif
5359 	kfree(orig_data);
5360 	return err;
5361 }
5362 
5363 #ifdef CONFIG_QUOTA
5364 static int ext4_statfs_project(struct super_block *sb,
5365 			       kprojid_t projid, struct kstatfs *buf)
5366 {
5367 	struct kqid qid;
5368 	struct dquot *dquot;
5369 	u64 limit;
5370 	u64 curblock;
5371 
5372 	qid = make_kqid_projid(projid);
5373 	dquot = dqget(sb, qid);
5374 	if (IS_ERR(dquot))
5375 		return PTR_ERR(dquot);
5376 	spin_lock(&dquot->dq_dqb_lock);
5377 
5378 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5379 		 dquot->dq_dqb.dqb_bsoftlimit :
5380 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5381 	if (limit && buf->f_blocks > limit) {
5382 		curblock = (dquot->dq_dqb.dqb_curspace +
5383 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5384 		buf->f_blocks = limit;
5385 		buf->f_bfree = buf->f_bavail =
5386 			(buf->f_blocks > curblock) ?
5387 			 (buf->f_blocks - curblock) : 0;
5388 	}
5389 
5390 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5391 		dquot->dq_dqb.dqb_isoftlimit :
5392 		dquot->dq_dqb.dqb_ihardlimit;
5393 	if (limit && buf->f_files > limit) {
5394 		buf->f_files = limit;
5395 		buf->f_ffree =
5396 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5397 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5398 	}
5399 
5400 	spin_unlock(&dquot->dq_dqb_lock);
5401 	dqput(dquot);
5402 	return 0;
5403 }
5404 #endif
5405 
5406 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5407 {
5408 	struct super_block *sb = dentry->d_sb;
5409 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5410 	struct ext4_super_block *es = sbi->s_es;
5411 	ext4_fsblk_t overhead = 0, resv_blocks;
5412 	u64 fsid;
5413 	s64 bfree;
5414 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5415 
5416 	if (!test_opt(sb, MINIX_DF))
5417 		overhead = sbi->s_overhead;
5418 
5419 	buf->f_type = EXT4_SUPER_MAGIC;
5420 	buf->f_bsize = sb->s_blocksize;
5421 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5422 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5423 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5424 	/* prevent underflow in case that few free space is available */
5425 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5426 	buf->f_bavail = buf->f_bfree -
5427 			(ext4_r_blocks_count(es) + resv_blocks);
5428 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5429 		buf->f_bavail = 0;
5430 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5431 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5432 	buf->f_namelen = EXT4_NAME_LEN;
5433 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5434 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5435 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5436 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5437 
5438 #ifdef CONFIG_QUOTA
5439 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5440 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5441 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5442 #endif
5443 	return 0;
5444 }
5445 
5446 
5447 #ifdef CONFIG_QUOTA
5448 
5449 /*
5450  * Helper functions so that transaction is started before we acquire dqio_sem
5451  * to keep correct lock ordering of transaction > dqio_sem
5452  */
5453 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5454 {
5455 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5456 }
5457 
5458 static int ext4_write_dquot(struct dquot *dquot)
5459 {
5460 	int ret, err;
5461 	handle_t *handle;
5462 	struct inode *inode;
5463 
5464 	inode = dquot_to_inode(dquot);
5465 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5466 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5467 	if (IS_ERR(handle))
5468 		return PTR_ERR(handle);
5469 	ret = dquot_commit(dquot);
5470 	err = ext4_journal_stop(handle);
5471 	if (!ret)
5472 		ret = err;
5473 	return ret;
5474 }
5475 
5476 static int ext4_acquire_dquot(struct dquot *dquot)
5477 {
5478 	int ret, err;
5479 	handle_t *handle;
5480 
5481 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5482 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5483 	if (IS_ERR(handle))
5484 		return PTR_ERR(handle);
5485 	ret = dquot_acquire(dquot);
5486 	err = ext4_journal_stop(handle);
5487 	if (!ret)
5488 		ret = err;
5489 	return ret;
5490 }
5491 
5492 static int ext4_release_dquot(struct dquot *dquot)
5493 {
5494 	int ret, err;
5495 	handle_t *handle;
5496 
5497 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5498 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5499 	if (IS_ERR(handle)) {
5500 		/* Release dquot anyway to avoid endless cycle in dqput() */
5501 		dquot_release(dquot);
5502 		return PTR_ERR(handle);
5503 	}
5504 	ret = dquot_release(dquot);
5505 	err = ext4_journal_stop(handle);
5506 	if (!ret)
5507 		ret = err;
5508 	return ret;
5509 }
5510 
5511 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5512 {
5513 	struct super_block *sb = dquot->dq_sb;
5514 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5515 
5516 	/* Are we journaling quotas? */
5517 	if (ext4_has_feature_quota(sb) ||
5518 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5519 		dquot_mark_dquot_dirty(dquot);
5520 		return ext4_write_dquot(dquot);
5521 	} else {
5522 		return dquot_mark_dquot_dirty(dquot);
5523 	}
5524 }
5525 
5526 static int ext4_write_info(struct super_block *sb, int type)
5527 {
5528 	int ret, err;
5529 	handle_t *handle;
5530 
5531 	/* Data block + inode block */
5532 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5533 	if (IS_ERR(handle))
5534 		return PTR_ERR(handle);
5535 	ret = dquot_commit_info(sb, type);
5536 	err = ext4_journal_stop(handle);
5537 	if (!ret)
5538 		ret = err;
5539 	return ret;
5540 }
5541 
5542 /*
5543  * Turn on quotas during mount time - we need to find
5544  * the quota file and such...
5545  */
5546 static int ext4_quota_on_mount(struct super_block *sb, int type)
5547 {
5548 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5549 					EXT4_SB(sb)->s_jquota_fmt, type);
5550 }
5551 
5552 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5553 {
5554 	struct ext4_inode_info *ei = EXT4_I(inode);
5555 
5556 	/* The first argument of lockdep_set_subclass has to be
5557 	 * *exactly* the same as the argument to init_rwsem() --- in
5558 	 * this case, in init_once() --- or lockdep gets unhappy
5559 	 * because the name of the lock is set using the
5560 	 * stringification of the argument to init_rwsem().
5561 	 */
5562 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5563 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5564 }
5565 
5566 /*
5567  * Standard function to be called on quota_on
5568  */
5569 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5570 			 const struct path *path)
5571 {
5572 	int err;
5573 
5574 	if (!test_opt(sb, QUOTA))
5575 		return -EINVAL;
5576 
5577 	/* Quotafile not on the same filesystem? */
5578 	if (path->dentry->d_sb != sb)
5579 		return -EXDEV;
5580 	/* Journaling quota? */
5581 	if (EXT4_SB(sb)->s_qf_names[type]) {
5582 		/* Quotafile not in fs root? */
5583 		if (path->dentry->d_parent != sb->s_root)
5584 			ext4_msg(sb, KERN_WARNING,
5585 				"Quota file not on filesystem root. "
5586 				"Journaled quota will not work");
5587 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5588 	} else {
5589 		/*
5590 		 * Clear the flag just in case mount options changed since
5591 		 * last time.
5592 		 */
5593 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5594 	}
5595 
5596 	/*
5597 	 * When we journal data on quota file, we have to flush journal to see
5598 	 * all updates to the file when we bypass pagecache...
5599 	 */
5600 	if (EXT4_SB(sb)->s_journal &&
5601 	    ext4_should_journal_data(d_inode(path->dentry))) {
5602 		/*
5603 		 * We don't need to lock updates but journal_flush() could
5604 		 * otherwise be livelocked...
5605 		 */
5606 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5607 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5608 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5609 		if (err)
5610 			return err;
5611 	}
5612 
5613 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5614 	err = dquot_quota_on(sb, type, format_id, path);
5615 	if (err) {
5616 		lockdep_set_quota_inode(path->dentry->d_inode,
5617 					     I_DATA_SEM_NORMAL);
5618 	} else {
5619 		struct inode *inode = d_inode(path->dentry);
5620 		handle_t *handle;
5621 
5622 		/*
5623 		 * Set inode flags to prevent userspace from messing with quota
5624 		 * files. If this fails, we return success anyway since quotas
5625 		 * are already enabled and this is not a hard failure.
5626 		 */
5627 		inode_lock(inode);
5628 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5629 		if (IS_ERR(handle))
5630 			goto unlock_inode;
5631 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5632 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5633 				S_NOATIME | S_IMMUTABLE);
5634 		ext4_mark_inode_dirty(handle, inode);
5635 		ext4_journal_stop(handle);
5636 	unlock_inode:
5637 		inode_unlock(inode);
5638 	}
5639 	return err;
5640 }
5641 
5642 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5643 			     unsigned int flags)
5644 {
5645 	int err;
5646 	struct inode *qf_inode;
5647 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5648 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5649 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5650 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5651 	};
5652 
5653 	BUG_ON(!ext4_has_feature_quota(sb));
5654 
5655 	if (!qf_inums[type])
5656 		return -EPERM;
5657 
5658 	qf_inode = ext4_iget(sb, qf_inums[type]);
5659 	if (IS_ERR(qf_inode)) {
5660 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5661 		return PTR_ERR(qf_inode);
5662 	}
5663 
5664 	/* Don't account quota for quota files to avoid recursion */
5665 	qf_inode->i_flags |= S_NOQUOTA;
5666 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5667 	err = dquot_enable(qf_inode, type, format_id, flags);
5668 	iput(qf_inode);
5669 	if (err)
5670 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5671 
5672 	return err;
5673 }
5674 
5675 /* Enable usage tracking for all quota types. */
5676 static int ext4_enable_quotas(struct super_block *sb)
5677 {
5678 	int type, err = 0;
5679 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5680 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5681 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5682 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5683 	};
5684 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5685 		test_opt(sb, USRQUOTA),
5686 		test_opt(sb, GRPQUOTA),
5687 		test_opt(sb, PRJQUOTA),
5688 	};
5689 
5690 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5691 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5692 		if (qf_inums[type]) {
5693 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5694 				DQUOT_USAGE_ENABLED |
5695 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5696 			if (err) {
5697 				ext4_warning(sb,
5698 					"Failed to enable quota tracking "
5699 					"(type=%d, err=%d). Please run "
5700 					"e2fsck to fix.", type, err);
5701 				for (type--; type >= 0; type--)
5702 					dquot_quota_off(sb, type);
5703 
5704 				return err;
5705 			}
5706 		}
5707 	}
5708 	return 0;
5709 }
5710 
5711 static int ext4_quota_off(struct super_block *sb, int type)
5712 {
5713 	struct inode *inode = sb_dqopt(sb)->files[type];
5714 	handle_t *handle;
5715 	int err;
5716 
5717 	/* Force all delayed allocation blocks to be allocated.
5718 	 * Caller already holds s_umount sem */
5719 	if (test_opt(sb, DELALLOC))
5720 		sync_filesystem(sb);
5721 
5722 	if (!inode || !igrab(inode))
5723 		goto out;
5724 
5725 	err = dquot_quota_off(sb, type);
5726 	if (err || ext4_has_feature_quota(sb))
5727 		goto out_put;
5728 
5729 	inode_lock(inode);
5730 	/*
5731 	 * Update modification times of quota files when userspace can
5732 	 * start looking at them. If we fail, we return success anyway since
5733 	 * this is not a hard failure and quotas are already disabled.
5734 	 */
5735 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5736 	if (IS_ERR(handle))
5737 		goto out_unlock;
5738 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5739 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5740 	inode->i_mtime = inode->i_ctime = current_time(inode);
5741 	ext4_mark_inode_dirty(handle, inode);
5742 	ext4_journal_stop(handle);
5743 out_unlock:
5744 	inode_unlock(inode);
5745 out_put:
5746 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5747 	iput(inode);
5748 	return err;
5749 out:
5750 	return dquot_quota_off(sb, type);
5751 }
5752 
5753 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5754  * acquiring the locks... As quota files are never truncated and quota code
5755  * itself serializes the operations (and no one else should touch the files)
5756  * we don't have to be afraid of races */
5757 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5758 			       size_t len, loff_t off)
5759 {
5760 	struct inode *inode = sb_dqopt(sb)->files[type];
5761 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5762 	int offset = off & (sb->s_blocksize - 1);
5763 	int tocopy;
5764 	size_t toread;
5765 	struct buffer_head *bh;
5766 	loff_t i_size = i_size_read(inode);
5767 
5768 	if (off > i_size)
5769 		return 0;
5770 	if (off+len > i_size)
5771 		len = i_size-off;
5772 	toread = len;
5773 	while (toread > 0) {
5774 		tocopy = sb->s_blocksize - offset < toread ?
5775 				sb->s_blocksize - offset : toread;
5776 		bh = ext4_bread(NULL, inode, blk, 0);
5777 		if (IS_ERR(bh))
5778 			return PTR_ERR(bh);
5779 		if (!bh)	/* A hole? */
5780 			memset(data, 0, tocopy);
5781 		else
5782 			memcpy(data, bh->b_data+offset, tocopy);
5783 		brelse(bh);
5784 		offset = 0;
5785 		toread -= tocopy;
5786 		data += tocopy;
5787 		blk++;
5788 	}
5789 	return len;
5790 }
5791 
5792 /* Write to quotafile (we know the transaction is already started and has
5793  * enough credits) */
5794 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5795 				const char *data, size_t len, loff_t off)
5796 {
5797 	struct inode *inode = sb_dqopt(sb)->files[type];
5798 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5799 	int err, offset = off & (sb->s_blocksize - 1);
5800 	int retries = 0;
5801 	struct buffer_head *bh;
5802 	handle_t *handle = journal_current_handle();
5803 
5804 	if (EXT4_SB(sb)->s_journal && !handle) {
5805 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5806 			" cancelled because transaction is not started",
5807 			(unsigned long long)off, (unsigned long long)len);
5808 		return -EIO;
5809 	}
5810 	/*
5811 	 * Since we account only one data block in transaction credits,
5812 	 * then it is impossible to cross a block boundary.
5813 	 */
5814 	if (sb->s_blocksize - offset < len) {
5815 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5816 			" cancelled because not block aligned",
5817 			(unsigned long long)off, (unsigned long long)len);
5818 		return -EIO;
5819 	}
5820 
5821 	do {
5822 		bh = ext4_bread(handle, inode, blk,
5823 				EXT4_GET_BLOCKS_CREATE |
5824 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5825 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5826 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5827 	if (IS_ERR(bh))
5828 		return PTR_ERR(bh);
5829 	if (!bh)
5830 		goto out;
5831 	BUFFER_TRACE(bh, "get write access");
5832 	err = ext4_journal_get_write_access(handle, bh);
5833 	if (err) {
5834 		brelse(bh);
5835 		return err;
5836 	}
5837 	lock_buffer(bh);
5838 	memcpy(bh->b_data+offset, data, len);
5839 	flush_dcache_page(bh->b_page);
5840 	unlock_buffer(bh);
5841 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5842 	brelse(bh);
5843 out:
5844 	if (inode->i_size < off + len) {
5845 		i_size_write(inode, off + len);
5846 		EXT4_I(inode)->i_disksize = inode->i_size;
5847 		ext4_mark_inode_dirty(handle, inode);
5848 	}
5849 	return len;
5850 }
5851 
5852 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5853 {
5854 	const struct quota_format_ops	*ops;
5855 
5856 	if (!sb_has_quota_loaded(sb, qid->type))
5857 		return -ESRCH;
5858 	ops = sb_dqopt(sb)->ops[qid->type];
5859 	if (!ops || !ops->get_next_id)
5860 		return -ENOSYS;
5861 	return dquot_get_next_id(sb, qid);
5862 }
5863 #endif
5864 
5865 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5866 		       const char *dev_name, void *data)
5867 {
5868 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5869 }
5870 
5871 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5872 static inline void register_as_ext2(void)
5873 {
5874 	int err = register_filesystem(&ext2_fs_type);
5875 	if (err)
5876 		printk(KERN_WARNING
5877 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5878 }
5879 
5880 static inline void unregister_as_ext2(void)
5881 {
5882 	unregister_filesystem(&ext2_fs_type);
5883 }
5884 
5885 static inline int ext2_feature_set_ok(struct super_block *sb)
5886 {
5887 	if (ext4_has_unknown_ext2_incompat_features(sb))
5888 		return 0;
5889 	if (sb_rdonly(sb))
5890 		return 1;
5891 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5892 		return 0;
5893 	return 1;
5894 }
5895 #else
5896 static inline void register_as_ext2(void) { }
5897 static inline void unregister_as_ext2(void) { }
5898 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5899 #endif
5900 
5901 static inline void register_as_ext3(void)
5902 {
5903 	int err = register_filesystem(&ext3_fs_type);
5904 	if (err)
5905 		printk(KERN_WARNING
5906 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5907 }
5908 
5909 static inline void unregister_as_ext3(void)
5910 {
5911 	unregister_filesystem(&ext3_fs_type);
5912 }
5913 
5914 static inline int ext3_feature_set_ok(struct super_block *sb)
5915 {
5916 	if (ext4_has_unknown_ext3_incompat_features(sb))
5917 		return 0;
5918 	if (!ext4_has_feature_journal(sb))
5919 		return 0;
5920 	if (sb_rdonly(sb))
5921 		return 1;
5922 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5923 		return 0;
5924 	return 1;
5925 }
5926 
5927 static struct file_system_type ext4_fs_type = {
5928 	.owner		= THIS_MODULE,
5929 	.name		= "ext4",
5930 	.mount		= ext4_mount,
5931 	.kill_sb	= kill_block_super,
5932 	.fs_flags	= FS_REQUIRES_DEV,
5933 };
5934 MODULE_ALIAS_FS("ext4");
5935 
5936 /* Shared across all ext4 file systems */
5937 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5938 
5939 static int __init ext4_init_fs(void)
5940 {
5941 	int i, err;
5942 
5943 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5944 	ext4_li_info = NULL;
5945 	mutex_init(&ext4_li_mtx);
5946 
5947 	/* Build-time check for flags consistency */
5948 	ext4_check_flag_values();
5949 
5950 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5951 		init_waitqueue_head(&ext4__ioend_wq[i]);
5952 
5953 	err = ext4_init_es();
5954 	if (err)
5955 		return err;
5956 
5957 	err = ext4_init_pageio();
5958 	if (err)
5959 		goto out5;
5960 
5961 	err = ext4_init_system_zone();
5962 	if (err)
5963 		goto out4;
5964 
5965 	err = ext4_init_sysfs();
5966 	if (err)
5967 		goto out3;
5968 
5969 	err = ext4_init_mballoc();
5970 	if (err)
5971 		goto out2;
5972 	err = init_inodecache();
5973 	if (err)
5974 		goto out1;
5975 	register_as_ext3();
5976 	register_as_ext2();
5977 	err = register_filesystem(&ext4_fs_type);
5978 	if (err)
5979 		goto out;
5980 
5981 	return 0;
5982 out:
5983 	unregister_as_ext2();
5984 	unregister_as_ext3();
5985 	destroy_inodecache();
5986 out1:
5987 	ext4_exit_mballoc();
5988 out2:
5989 	ext4_exit_sysfs();
5990 out3:
5991 	ext4_exit_system_zone();
5992 out4:
5993 	ext4_exit_pageio();
5994 out5:
5995 	ext4_exit_es();
5996 
5997 	return err;
5998 }
5999 
6000 static void __exit ext4_exit_fs(void)
6001 {
6002 	ext4_destroy_lazyinit_thread();
6003 	unregister_as_ext2();
6004 	unregister_as_ext3();
6005 	unregister_filesystem(&ext4_fs_type);
6006 	destroy_inodecache();
6007 	ext4_exit_mballoc();
6008 	ext4_exit_sysfs();
6009 	ext4_exit_system_zone();
6010 	ext4_exit_pageio();
6011 	ext4_exit_es();
6012 }
6013 
6014 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6015 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6016 MODULE_LICENSE("GPL");
6017 MODULE_SOFTDEP("pre: crc32c");
6018 module_init(ext4_init_fs)
6019 module_exit(ext4_exit_fs)
6020