xref: /openbmc/linux/fs/ext4/super.c (revision 3b23dc52)
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 
316 static void __save_error_info(struct super_block *sb, const char *func,
317 			    unsigned int line)
318 {
319 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
320 
321 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
322 	if (bdev_read_only(sb->s_bdev))
323 		return;
324 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
325 	es->s_last_error_time = cpu_to_le32(get_seconds());
326 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
327 	es->s_last_error_line = cpu_to_le32(line);
328 	if (!es->s_first_error_time) {
329 		es->s_first_error_time = es->s_last_error_time;
330 		strncpy(es->s_first_error_func, func,
331 			sizeof(es->s_first_error_func));
332 		es->s_first_error_line = cpu_to_le32(line);
333 		es->s_first_error_ino = es->s_last_error_ino;
334 		es->s_first_error_block = es->s_last_error_block;
335 	}
336 	/*
337 	 * Start the daily error reporting function if it hasn't been
338 	 * started already
339 	 */
340 	if (!es->s_error_count)
341 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
342 	le32_add_cpu(&es->s_error_count, 1);
343 }
344 
345 static void save_error_info(struct super_block *sb, const char *func,
346 			    unsigned int line)
347 {
348 	__save_error_info(sb, func, line);
349 	ext4_commit_super(sb, 1);
350 }
351 
352 /*
353  * The del_gendisk() function uninitializes the disk-specific data
354  * structures, including the bdi structure, without telling anyone
355  * else.  Once this happens, any attempt to call mark_buffer_dirty()
356  * (for example, by ext4_commit_super), will cause a kernel OOPS.
357  * This is a kludge to prevent these oops until we can put in a proper
358  * hook in del_gendisk() to inform the VFS and file system layers.
359  */
360 static int block_device_ejected(struct super_block *sb)
361 {
362 	struct inode *bd_inode = sb->s_bdev->bd_inode;
363 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
364 
365 	return bdi->dev == NULL;
366 }
367 
368 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
369 {
370 	struct super_block		*sb = journal->j_private;
371 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
372 	int				error = is_journal_aborted(journal);
373 	struct ext4_journal_cb_entry	*jce;
374 
375 	BUG_ON(txn->t_state == T_FINISHED);
376 
377 	ext4_process_freed_data(sb, txn->t_tid);
378 
379 	spin_lock(&sbi->s_md_lock);
380 	while (!list_empty(&txn->t_private_list)) {
381 		jce = list_entry(txn->t_private_list.next,
382 				 struct ext4_journal_cb_entry, jce_list);
383 		list_del_init(&jce->jce_list);
384 		spin_unlock(&sbi->s_md_lock);
385 		jce->jce_func(sb, jce, error);
386 		spin_lock(&sbi->s_md_lock);
387 	}
388 	spin_unlock(&sbi->s_md_lock);
389 }
390 
391 /* Deal with the reporting of failure conditions on a filesystem such as
392  * inconsistencies detected or read IO failures.
393  *
394  * On ext2, we can store the error state of the filesystem in the
395  * superblock.  That is not possible on ext4, because we may have other
396  * write ordering constraints on the superblock which prevent us from
397  * writing it out straight away; and given that the journal is about to
398  * be aborted, we can't rely on the current, or future, transactions to
399  * write out the superblock safely.
400  *
401  * We'll just use the jbd2_journal_abort() error code to record an error in
402  * the journal instead.  On recovery, the journal will complain about
403  * that error until we've noted it down and cleared it.
404  */
405 
406 static void ext4_handle_error(struct super_block *sb)
407 {
408 	if (test_opt(sb, WARN_ON_ERROR))
409 		WARN_ON_ONCE(1);
410 
411 	if (sb_rdonly(sb))
412 		return;
413 
414 	if (!test_opt(sb, ERRORS_CONT)) {
415 		journal_t *journal = EXT4_SB(sb)->s_journal;
416 
417 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
418 		if (journal)
419 			jbd2_journal_abort(journal, -EIO);
420 	}
421 	if (test_opt(sb, ERRORS_RO)) {
422 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
423 		/*
424 		 * Make sure updated value of ->s_mount_flags will be visible
425 		 * before ->s_flags update
426 		 */
427 		smp_wmb();
428 		sb->s_flags |= SB_RDONLY;
429 	}
430 	if (test_opt(sb, ERRORS_PANIC)) {
431 		if (EXT4_SB(sb)->s_journal &&
432 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
433 			return;
434 		panic("EXT4-fs (device %s): panic forced after error\n",
435 			sb->s_id);
436 	}
437 }
438 
439 #define ext4_error_ratelimit(sb)					\
440 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
441 			     "EXT4-fs error")
442 
443 void __ext4_error(struct super_block *sb, const char *function,
444 		  unsigned int line, const char *fmt, ...)
445 {
446 	struct va_format vaf;
447 	va_list args;
448 
449 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
450 		return;
451 
452 	trace_ext4_error(sb, function, line);
453 	if (ext4_error_ratelimit(sb)) {
454 		va_start(args, fmt);
455 		vaf.fmt = fmt;
456 		vaf.va = &args;
457 		printk(KERN_CRIT
458 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
459 		       sb->s_id, function, line, current->comm, &vaf);
460 		va_end(args);
461 	}
462 	save_error_info(sb, function, line);
463 	ext4_handle_error(sb);
464 }
465 
466 void __ext4_error_inode(struct inode *inode, const char *function,
467 			unsigned int line, ext4_fsblk_t block,
468 			const char *fmt, ...)
469 {
470 	va_list args;
471 	struct va_format vaf;
472 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
473 
474 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
475 		return;
476 
477 	trace_ext4_error(inode->i_sb, function, line);
478 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
479 	es->s_last_error_block = cpu_to_le64(block);
480 	if (ext4_error_ratelimit(inode->i_sb)) {
481 		va_start(args, fmt);
482 		vaf.fmt = fmt;
483 		vaf.va = &args;
484 		if (block)
485 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
486 			       "inode #%lu: block %llu: comm %s: %pV\n",
487 			       inode->i_sb->s_id, function, line, inode->i_ino,
488 			       block, current->comm, &vaf);
489 		else
490 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
491 			       "inode #%lu: comm %s: %pV\n",
492 			       inode->i_sb->s_id, function, line, inode->i_ino,
493 			       current->comm, &vaf);
494 		va_end(args);
495 	}
496 	save_error_info(inode->i_sb, function, line);
497 	ext4_handle_error(inode->i_sb);
498 }
499 
500 void __ext4_error_file(struct file *file, const char *function,
501 		       unsigned int line, ext4_fsblk_t block,
502 		       const char *fmt, ...)
503 {
504 	va_list args;
505 	struct va_format vaf;
506 	struct ext4_super_block *es;
507 	struct inode *inode = file_inode(file);
508 	char pathname[80], *path;
509 
510 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
511 		return;
512 
513 	trace_ext4_error(inode->i_sb, function, line);
514 	es = EXT4_SB(inode->i_sb)->s_es;
515 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
516 	if (ext4_error_ratelimit(inode->i_sb)) {
517 		path = file_path(file, pathname, sizeof(pathname));
518 		if (IS_ERR(path))
519 			path = "(unknown)";
520 		va_start(args, fmt);
521 		vaf.fmt = fmt;
522 		vaf.va = &args;
523 		if (block)
524 			printk(KERN_CRIT
525 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
526 			       "block %llu: comm %s: path %s: %pV\n",
527 			       inode->i_sb->s_id, function, line, inode->i_ino,
528 			       block, current->comm, path, &vaf);
529 		else
530 			printk(KERN_CRIT
531 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
532 			       "comm %s: path %s: %pV\n",
533 			       inode->i_sb->s_id, function, line, inode->i_ino,
534 			       current->comm, path, &vaf);
535 		va_end(args);
536 	}
537 	save_error_info(inode->i_sb, function, line);
538 	ext4_handle_error(inode->i_sb);
539 }
540 
541 const char *ext4_decode_error(struct super_block *sb, int errno,
542 			      char nbuf[16])
543 {
544 	char *errstr = NULL;
545 
546 	switch (errno) {
547 	case -EFSCORRUPTED:
548 		errstr = "Corrupt filesystem";
549 		break;
550 	case -EFSBADCRC:
551 		errstr = "Filesystem failed CRC";
552 		break;
553 	case -EIO:
554 		errstr = "IO failure";
555 		break;
556 	case -ENOMEM:
557 		errstr = "Out of memory";
558 		break;
559 	case -EROFS:
560 		if (!sb || (EXT4_SB(sb)->s_journal &&
561 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
562 			errstr = "Journal has aborted";
563 		else
564 			errstr = "Readonly filesystem";
565 		break;
566 	default:
567 		/* If the caller passed in an extra buffer for unknown
568 		 * errors, textualise them now.  Else we just return
569 		 * NULL. */
570 		if (nbuf) {
571 			/* Check for truncated error codes... */
572 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
573 				errstr = nbuf;
574 		}
575 		break;
576 	}
577 
578 	return errstr;
579 }
580 
581 /* __ext4_std_error decodes expected errors from journaling functions
582  * automatically and invokes the appropriate error response.  */
583 
584 void __ext4_std_error(struct super_block *sb, const char *function,
585 		      unsigned int line, int errno)
586 {
587 	char nbuf[16];
588 	const char *errstr;
589 
590 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
591 		return;
592 
593 	/* Special case: if the error is EROFS, and we're not already
594 	 * inside a transaction, then there's really no point in logging
595 	 * an error. */
596 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
597 		return;
598 
599 	if (ext4_error_ratelimit(sb)) {
600 		errstr = ext4_decode_error(sb, errno, nbuf);
601 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
602 		       sb->s_id, function, line, errstr);
603 	}
604 
605 	save_error_info(sb, function, line);
606 	ext4_handle_error(sb);
607 }
608 
609 /*
610  * ext4_abort is a much stronger failure handler than ext4_error.  The
611  * abort function may be used to deal with unrecoverable failures such
612  * as journal IO errors or ENOMEM at a critical moment in log management.
613  *
614  * We unconditionally force the filesystem into an ABORT|READONLY state,
615  * unless the error response on the fs has been set to panic in which
616  * case we take the easy way out and panic immediately.
617  */
618 
619 void __ext4_abort(struct super_block *sb, const char *function,
620 		unsigned int line, const char *fmt, ...)
621 {
622 	struct va_format vaf;
623 	va_list args;
624 
625 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
626 		return;
627 
628 	save_error_info(sb, function, line);
629 	va_start(args, fmt);
630 	vaf.fmt = fmt;
631 	vaf.va = &args;
632 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
633 	       sb->s_id, function, line, &vaf);
634 	va_end(args);
635 
636 	if (sb_rdonly(sb) == 0) {
637 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
638 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
639 		/*
640 		 * Make sure updated value of ->s_mount_flags will be visible
641 		 * before ->s_flags update
642 		 */
643 		smp_wmb();
644 		sb->s_flags |= SB_RDONLY;
645 		if (EXT4_SB(sb)->s_journal)
646 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
647 		save_error_info(sb, function, line);
648 	}
649 	if (test_opt(sb, ERRORS_PANIC)) {
650 		if (EXT4_SB(sb)->s_journal &&
651 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
652 			return;
653 		panic("EXT4-fs panic from previous error\n");
654 	}
655 }
656 
657 void __ext4_msg(struct super_block *sb,
658 		const char *prefix, const char *fmt, ...)
659 {
660 	struct va_format vaf;
661 	va_list args;
662 
663 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
664 		return;
665 
666 	va_start(args, fmt);
667 	vaf.fmt = fmt;
668 	vaf.va = &args;
669 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
670 	va_end(args);
671 }
672 
673 #define ext4_warning_ratelimit(sb)					\
674 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
675 			     "EXT4-fs warning")
676 
677 void __ext4_warning(struct super_block *sb, const char *function,
678 		    unsigned int line, const char *fmt, ...)
679 {
680 	struct va_format vaf;
681 	va_list args;
682 
683 	if (!ext4_warning_ratelimit(sb))
684 		return;
685 
686 	va_start(args, fmt);
687 	vaf.fmt = fmt;
688 	vaf.va = &args;
689 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
690 	       sb->s_id, function, line, &vaf);
691 	va_end(args);
692 }
693 
694 void __ext4_warning_inode(const struct inode *inode, const char *function,
695 			  unsigned int line, const char *fmt, ...)
696 {
697 	struct va_format vaf;
698 	va_list args;
699 
700 	if (!ext4_warning_ratelimit(inode->i_sb))
701 		return;
702 
703 	va_start(args, fmt);
704 	vaf.fmt = fmt;
705 	vaf.va = &args;
706 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
707 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
708 	       function, line, inode->i_ino, current->comm, &vaf);
709 	va_end(args);
710 }
711 
712 void __ext4_grp_locked_error(const char *function, unsigned int line,
713 			     struct super_block *sb, ext4_group_t grp,
714 			     unsigned long ino, ext4_fsblk_t block,
715 			     const char *fmt, ...)
716 __releases(bitlock)
717 __acquires(bitlock)
718 {
719 	struct va_format vaf;
720 	va_list args;
721 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
722 
723 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
724 		return;
725 
726 	trace_ext4_error(sb, function, line);
727 	es->s_last_error_ino = cpu_to_le32(ino);
728 	es->s_last_error_block = cpu_to_le64(block);
729 	__save_error_info(sb, function, line);
730 
731 	if (ext4_error_ratelimit(sb)) {
732 		va_start(args, fmt);
733 		vaf.fmt = fmt;
734 		vaf.va = &args;
735 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
736 		       sb->s_id, function, line, grp);
737 		if (ino)
738 			printk(KERN_CONT "inode %lu: ", ino);
739 		if (block)
740 			printk(KERN_CONT "block %llu:",
741 			       (unsigned long long) block);
742 		printk(KERN_CONT "%pV\n", &vaf);
743 		va_end(args);
744 	}
745 
746 	if (test_opt(sb, WARN_ON_ERROR))
747 		WARN_ON_ONCE(1);
748 
749 	if (test_opt(sb, ERRORS_CONT)) {
750 		ext4_commit_super(sb, 0);
751 		return;
752 	}
753 
754 	ext4_unlock_group(sb, grp);
755 	ext4_commit_super(sb, 1);
756 	ext4_handle_error(sb);
757 	/*
758 	 * We only get here in the ERRORS_RO case; relocking the group
759 	 * may be dangerous, but nothing bad will happen since the
760 	 * filesystem will have already been marked read/only and the
761 	 * journal has been aborted.  We return 1 as a hint to callers
762 	 * who might what to use the return value from
763 	 * ext4_grp_locked_error() to distinguish between the
764 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
765 	 * aggressively from the ext4 function in question, with a
766 	 * more appropriate error code.
767 	 */
768 	ext4_lock_group(sb, grp);
769 	return;
770 }
771 
772 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
773 				     ext4_group_t group,
774 				     unsigned int flags)
775 {
776 	struct ext4_sb_info *sbi = EXT4_SB(sb);
777 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
778 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
779 
780 	if ((flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) &&
781 	    !EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) {
782 		percpu_counter_sub(&sbi->s_freeclusters_counter,
783 					grp->bb_free);
784 		set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
785 			&grp->bb_state);
786 	}
787 
788 	if ((flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) &&
789 	    !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
790 		if (gdp) {
791 			int count;
792 
793 			count = ext4_free_inodes_count(sb, gdp);
794 			percpu_counter_sub(&sbi->s_freeinodes_counter,
795 					   count);
796 		}
797 		set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
798 			&grp->bb_state);
799 	}
800 }
801 
802 void ext4_update_dynamic_rev(struct super_block *sb)
803 {
804 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
805 
806 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
807 		return;
808 
809 	ext4_warning(sb,
810 		     "updating to rev %d because of new feature flag, "
811 		     "running e2fsck is recommended",
812 		     EXT4_DYNAMIC_REV);
813 
814 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
815 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
816 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
817 	/* leave es->s_feature_*compat flags alone */
818 	/* es->s_uuid will be set by e2fsck if empty */
819 
820 	/*
821 	 * The rest of the superblock fields should be zero, and if not it
822 	 * means they are likely already in use, so leave them alone.  We
823 	 * can leave it up to e2fsck to clean up any inconsistencies there.
824 	 */
825 }
826 
827 /*
828  * Open the external journal device
829  */
830 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
831 {
832 	struct block_device *bdev;
833 	char b[BDEVNAME_SIZE];
834 
835 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
836 	if (IS_ERR(bdev))
837 		goto fail;
838 	return bdev;
839 
840 fail:
841 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
842 			__bdevname(dev, b), PTR_ERR(bdev));
843 	return NULL;
844 }
845 
846 /*
847  * Release the journal device
848  */
849 static void ext4_blkdev_put(struct block_device *bdev)
850 {
851 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
852 }
853 
854 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
855 {
856 	struct block_device *bdev;
857 	bdev = sbi->journal_bdev;
858 	if (bdev) {
859 		ext4_blkdev_put(bdev);
860 		sbi->journal_bdev = NULL;
861 	}
862 }
863 
864 static inline struct inode *orphan_list_entry(struct list_head *l)
865 {
866 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
867 }
868 
869 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
870 {
871 	struct list_head *l;
872 
873 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
874 		 le32_to_cpu(sbi->s_es->s_last_orphan));
875 
876 	printk(KERN_ERR "sb_info orphan list:\n");
877 	list_for_each(l, &sbi->s_orphan) {
878 		struct inode *inode = orphan_list_entry(l);
879 		printk(KERN_ERR "  "
880 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
881 		       inode->i_sb->s_id, inode->i_ino, inode,
882 		       inode->i_mode, inode->i_nlink,
883 		       NEXT_ORPHAN(inode));
884 	}
885 }
886 
887 #ifdef CONFIG_QUOTA
888 static int ext4_quota_off(struct super_block *sb, int type);
889 
890 static inline void ext4_quota_off_umount(struct super_block *sb)
891 {
892 	int type;
893 
894 	/* Use our quota_off function to clear inode flags etc. */
895 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
896 		ext4_quota_off(sb, type);
897 }
898 #else
899 static inline void ext4_quota_off_umount(struct super_block *sb)
900 {
901 }
902 #endif
903 
904 static void ext4_put_super(struct super_block *sb)
905 {
906 	struct ext4_sb_info *sbi = EXT4_SB(sb);
907 	struct ext4_super_block *es = sbi->s_es;
908 	int aborted = 0;
909 	int i, err;
910 
911 	ext4_unregister_li_request(sb);
912 	ext4_quota_off_umount(sb);
913 
914 	destroy_workqueue(sbi->rsv_conversion_wq);
915 
916 	if (sbi->s_journal) {
917 		aborted = is_journal_aborted(sbi->s_journal);
918 		err = jbd2_journal_destroy(sbi->s_journal);
919 		sbi->s_journal = NULL;
920 		if ((err < 0) && !aborted)
921 			ext4_abort(sb, "Couldn't clean up the journal");
922 	}
923 
924 	ext4_unregister_sysfs(sb);
925 	ext4_es_unregister_shrinker(sbi);
926 	del_timer_sync(&sbi->s_err_report);
927 	ext4_release_system_zone(sb);
928 	ext4_mb_release(sb);
929 	ext4_ext_release(sb);
930 
931 	if (!sb_rdonly(sb) && !aborted) {
932 		ext4_clear_feature_journal_needs_recovery(sb);
933 		es->s_state = cpu_to_le16(sbi->s_mount_state);
934 	}
935 	if (!sb_rdonly(sb))
936 		ext4_commit_super(sb, 1);
937 
938 	for (i = 0; i < sbi->s_gdb_count; i++)
939 		brelse(sbi->s_group_desc[i]);
940 	kvfree(sbi->s_group_desc);
941 	kvfree(sbi->s_flex_groups);
942 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
943 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
944 	percpu_counter_destroy(&sbi->s_dirs_counter);
945 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
946 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
947 #ifdef CONFIG_QUOTA
948 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
949 		kfree(sbi->s_qf_names[i]);
950 #endif
951 
952 	/* Debugging code just in case the in-memory inode orphan list
953 	 * isn't empty.  The on-disk one can be non-empty if we've
954 	 * detected an error and taken the fs readonly, but the
955 	 * in-memory list had better be clean by this point. */
956 	if (!list_empty(&sbi->s_orphan))
957 		dump_orphan_list(sb, sbi);
958 	J_ASSERT(list_empty(&sbi->s_orphan));
959 
960 	sync_blockdev(sb->s_bdev);
961 	invalidate_bdev(sb->s_bdev);
962 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
963 		/*
964 		 * Invalidate the journal device's buffers.  We don't want them
965 		 * floating about in memory - the physical journal device may
966 		 * hotswapped, and it breaks the `ro-after' testing code.
967 		 */
968 		sync_blockdev(sbi->journal_bdev);
969 		invalidate_bdev(sbi->journal_bdev);
970 		ext4_blkdev_remove(sbi);
971 	}
972 	if (sbi->s_ea_inode_cache) {
973 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
974 		sbi->s_ea_inode_cache = NULL;
975 	}
976 	if (sbi->s_ea_block_cache) {
977 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
978 		sbi->s_ea_block_cache = NULL;
979 	}
980 	if (sbi->s_mmp_tsk)
981 		kthread_stop(sbi->s_mmp_tsk);
982 	brelse(sbi->s_sbh);
983 	sb->s_fs_info = NULL;
984 	/*
985 	 * Now that we are completely done shutting down the
986 	 * superblock, we need to actually destroy the kobject.
987 	 */
988 	kobject_put(&sbi->s_kobj);
989 	wait_for_completion(&sbi->s_kobj_unregister);
990 	if (sbi->s_chksum_driver)
991 		crypto_free_shash(sbi->s_chksum_driver);
992 	kfree(sbi->s_blockgroup_lock);
993 	fs_put_dax(sbi->s_daxdev);
994 	kfree(sbi);
995 }
996 
997 static struct kmem_cache *ext4_inode_cachep;
998 
999 /*
1000  * Called inside transaction, so use GFP_NOFS
1001  */
1002 static struct inode *ext4_alloc_inode(struct super_block *sb)
1003 {
1004 	struct ext4_inode_info *ei;
1005 
1006 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1007 	if (!ei)
1008 		return NULL;
1009 
1010 	inode_set_iversion(&ei->vfs_inode, 1);
1011 	spin_lock_init(&ei->i_raw_lock);
1012 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1013 	spin_lock_init(&ei->i_prealloc_lock);
1014 	ext4_es_init_tree(&ei->i_es_tree);
1015 	rwlock_init(&ei->i_es_lock);
1016 	INIT_LIST_HEAD(&ei->i_es_list);
1017 	ei->i_es_all_nr = 0;
1018 	ei->i_es_shk_nr = 0;
1019 	ei->i_es_shrink_lblk = 0;
1020 	ei->i_reserved_data_blocks = 0;
1021 	ei->i_da_metadata_calc_len = 0;
1022 	ei->i_da_metadata_calc_last_lblock = 0;
1023 	spin_lock_init(&(ei->i_block_reservation_lock));
1024 #ifdef CONFIG_QUOTA
1025 	ei->i_reserved_quota = 0;
1026 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1027 #endif
1028 	ei->jinode = NULL;
1029 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1030 	spin_lock_init(&ei->i_completed_io_lock);
1031 	ei->i_sync_tid = 0;
1032 	ei->i_datasync_tid = 0;
1033 	atomic_set(&ei->i_unwritten, 0);
1034 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1035 	return &ei->vfs_inode;
1036 }
1037 
1038 static int ext4_drop_inode(struct inode *inode)
1039 {
1040 	int drop = generic_drop_inode(inode);
1041 
1042 	trace_ext4_drop_inode(inode, drop);
1043 	return drop;
1044 }
1045 
1046 static void ext4_i_callback(struct rcu_head *head)
1047 {
1048 	struct inode *inode = container_of(head, struct inode, i_rcu);
1049 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1050 }
1051 
1052 static void ext4_destroy_inode(struct inode *inode)
1053 {
1054 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1055 		ext4_msg(inode->i_sb, KERN_ERR,
1056 			 "Inode %lu (%p): orphan list check failed!",
1057 			 inode->i_ino, EXT4_I(inode));
1058 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1059 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1060 				true);
1061 		dump_stack();
1062 	}
1063 	call_rcu(&inode->i_rcu, ext4_i_callback);
1064 }
1065 
1066 static void init_once(void *foo)
1067 {
1068 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1069 
1070 	INIT_LIST_HEAD(&ei->i_orphan);
1071 	init_rwsem(&ei->xattr_sem);
1072 	init_rwsem(&ei->i_data_sem);
1073 	init_rwsem(&ei->i_mmap_sem);
1074 	inode_init_once(&ei->vfs_inode);
1075 }
1076 
1077 static int __init init_inodecache(void)
1078 {
1079 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1080 				sizeof(struct ext4_inode_info), 0,
1081 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1082 					SLAB_ACCOUNT),
1083 				offsetof(struct ext4_inode_info, i_data),
1084 				sizeof_field(struct ext4_inode_info, i_data),
1085 				init_once);
1086 	if (ext4_inode_cachep == NULL)
1087 		return -ENOMEM;
1088 	return 0;
1089 }
1090 
1091 static void destroy_inodecache(void)
1092 {
1093 	/*
1094 	 * Make sure all delayed rcu free inodes are flushed before we
1095 	 * destroy cache.
1096 	 */
1097 	rcu_barrier();
1098 	kmem_cache_destroy(ext4_inode_cachep);
1099 }
1100 
1101 void ext4_clear_inode(struct inode *inode)
1102 {
1103 	invalidate_inode_buffers(inode);
1104 	clear_inode(inode);
1105 	dquot_drop(inode);
1106 	ext4_discard_preallocations(inode);
1107 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1108 	if (EXT4_I(inode)->jinode) {
1109 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1110 					       EXT4_I(inode)->jinode);
1111 		jbd2_free_inode(EXT4_I(inode)->jinode);
1112 		EXT4_I(inode)->jinode = NULL;
1113 	}
1114 	fscrypt_put_encryption_info(inode);
1115 }
1116 
1117 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1118 					u64 ino, u32 generation)
1119 {
1120 	struct inode *inode;
1121 
1122 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1123 		return ERR_PTR(-ESTALE);
1124 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1125 		return ERR_PTR(-ESTALE);
1126 
1127 	/* iget isn't really right if the inode is currently unallocated!!
1128 	 *
1129 	 * ext4_read_inode will return a bad_inode if the inode had been
1130 	 * deleted, so we should be safe.
1131 	 *
1132 	 * Currently we don't know the generation for parent directory, so
1133 	 * a generation of 0 means "accept any"
1134 	 */
1135 	inode = ext4_iget_normal(sb, ino);
1136 	if (IS_ERR(inode))
1137 		return ERR_CAST(inode);
1138 	if (generation && inode->i_generation != generation) {
1139 		iput(inode);
1140 		return ERR_PTR(-ESTALE);
1141 	}
1142 
1143 	return inode;
1144 }
1145 
1146 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1147 					int fh_len, int fh_type)
1148 {
1149 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1150 				    ext4_nfs_get_inode);
1151 }
1152 
1153 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1154 					int fh_len, int fh_type)
1155 {
1156 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1157 				    ext4_nfs_get_inode);
1158 }
1159 
1160 /*
1161  * Try to release metadata pages (indirect blocks, directories) which are
1162  * mapped via the block device.  Since these pages could have journal heads
1163  * which would prevent try_to_free_buffers() from freeing them, we must use
1164  * jbd2 layer's try_to_free_buffers() function to release them.
1165  */
1166 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1167 				 gfp_t wait)
1168 {
1169 	journal_t *journal = EXT4_SB(sb)->s_journal;
1170 
1171 	WARN_ON(PageChecked(page));
1172 	if (!page_has_buffers(page))
1173 		return 0;
1174 	if (journal)
1175 		return jbd2_journal_try_to_free_buffers(journal, page,
1176 						wait & ~__GFP_DIRECT_RECLAIM);
1177 	return try_to_free_buffers(page);
1178 }
1179 
1180 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1181 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1182 {
1183 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1184 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1185 }
1186 
1187 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1188 							void *fs_data)
1189 {
1190 	handle_t *handle = fs_data;
1191 	int res, res2, credits, retries = 0;
1192 
1193 	/*
1194 	 * Encrypting the root directory is not allowed because e2fsck expects
1195 	 * lost+found to exist and be unencrypted, and encrypting the root
1196 	 * directory would imply encrypting the lost+found directory as well as
1197 	 * the filename "lost+found" itself.
1198 	 */
1199 	if (inode->i_ino == EXT4_ROOT_INO)
1200 		return -EPERM;
1201 
1202 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1203 		return -EINVAL;
1204 
1205 	res = ext4_convert_inline_data(inode);
1206 	if (res)
1207 		return res;
1208 
1209 	/*
1210 	 * If a journal handle was specified, then the encryption context is
1211 	 * being set on a new inode via inheritance and is part of a larger
1212 	 * transaction to create the inode.  Otherwise the encryption context is
1213 	 * being set on an existing inode in its own transaction.  Only in the
1214 	 * latter case should the "retry on ENOSPC" logic be used.
1215 	 */
1216 
1217 	if (handle) {
1218 		res = ext4_xattr_set_handle(handle, inode,
1219 					    EXT4_XATTR_INDEX_ENCRYPTION,
1220 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1221 					    ctx, len, 0);
1222 		if (!res) {
1223 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1224 			ext4_clear_inode_state(inode,
1225 					EXT4_STATE_MAY_INLINE_DATA);
1226 			/*
1227 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1228 			 * S_DAX may be disabled
1229 			 */
1230 			ext4_set_inode_flags(inode);
1231 		}
1232 		return res;
1233 	}
1234 
1235 	res = dquot_initialize(inode);
1236 	if (res)
1237 		return res;
1238 retry:
1239 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1240 				     &credits);
1241 	if (res)
1242 		return res;
1243 
1244 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1245 	if (IS_ERR(handle))
1246 		return PTR_ERR(handle);
1247 
1248 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1249 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1250 				    ctx, len, 0);
1251 	if (!res) {
1252 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1253 		/*
1254 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1255 		 * S_DAX may be disabled
1256 		 */
1257 		ext4_set_inode_flags(inode);
1258 		res = ext4_mark_inode_dirty(handle, inode);
1259 		if (res)
1260 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1261 	}
1262 	res2 = ext4_journal_stop(handle);
1263 
1264 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1265 		goto retry;
1266 	if (!res)
1267 		res = res2;
1268 	return res;
1269 }
1270 
1271 static bool ext4_dummy_context(struct inode *inode)
1272 {
1273 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1274 }
1275 
1276 static const struct fscrypt_operations ext4_cryptops = {
1277 	.key_prefix		= "ext4:",
1278 	.get_context		= ext4_get_context,
1279 	.set_context		= ext4_set_context,
1280 	.dummy_context		= ext4_dummy_context,
1281 	.empty_dir		= ext4_empty_dir,
1282 	.max_namelen		= EXT4_NAME_LEN,
1283 };
1284 #endif
1285 
1286 #ifdef CONFIG_QUOTA
1287 static const char * const quotatypes[] = INITQFNAMES;
1288 #define QTYPE2NAME(t) (quotatypes[t])
1289 
1290 static int ext4_write_dquot(struct dquot *dquot);
1291 static int ext4_acquire_dquot(struct dquot *dquot);
1292 static int ext4_release_dquot(struct dquot *dquot);
1293 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1294 static int ext4_write_info(struct super_block *sb, int type);
1295 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1296 			 const struct path *path);
1297 static int ext4_quota_on_mount(struct super_block *sb, int type);
1298 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1299 			       size_t len, loff_t off);
1300 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1301 				const char *data, size_t len, loff_t off);
1302 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1303 			     unsigned int flags);
1304 static int ext4_enable_quotas(struct super_block *sb);
1305 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1306 
1307 static struct dquot **ext4_get_dquots(struct inode *inode)
1308 {
1309 	return EXT4_I(inode)->i_dquot;
1310 }
1311 
1312 static const struct dquot_operations ext4_quota_operations = {
1313 	.get_reserved_space	= ext4_get_reserved_space,
1314 	.write_dquot		= ext4_write_dquot,
1315 	.acquire_dquot		= ext4_acquire_dquot,
1316 	.release_dquot		= ext4_release_dquot,
1317 	.mark_dirty		= ext4_mark_dquot_dirty,
1318 	.write_info		= ext4_write_info,
1319 	.alloc_dquot		= dquot_alloc,
1320 	.destroy_dquot		= dquot_destroy,
1321 	.get_projid		= ext4_get_projid,
1322 	.get_inode_usage	= ext4_get_inode_usage,
1323 	.get_next_id		= ext4_get_next_id,
1324 };
1325 
1326 static const struct quotactl_ops ext4_qctl_operations = {
1327 	.quota_on	= ext4_quota_on,
1328 	.quota_off	= ext4_quota_off,
1329 	.quota_sync	= dquot_quota_sync,
1330 	.get_state	= dquot_get_state,
1331 	.set_info	= dquot_set_dqinfo,
1332 	.get_dqblk	= dquot_get_dqblk,
1333 	.set_dqblk	= dquot_set_dqblk,
1334 	.get_nextdqblk	= dquot_get_next_dqblk,
1335 };
1336 #endif
1337 
1338 static const struct super_operations ext4_sops = {
1339 	.alloc_inode	= ext4_alloc_inode,
1340 	.destroy_inode	= ext4_destroy_inode,
1341 	.write_inode	= ext4_write_inode,
1342 	.dirty_inode	= ext4_dirty_inode,
1343 	.drop_inode	= ext4_drop_inode,
1344 	.evict_inode	= ext4_evict_inode,
1345 	.put_super	= ext4_put_super,
1346 	.sync_fs	= ext4_sync_fs,
1347 	.freeze_fs	= ext4_freeze,
1348 	.unfreeze_fs	= ext4_unfreeze,
1349 	.statfs		= ext4_statfs,
1350 	.remount_fs	= ext4_remount,
1351 	.show_options	= ext4_show_options,
1352 #ifdef CONFIG_QUOTA
1353 	.quota_read	= ext4_quota_read,
1354 	.quota_write	= ext4_quota_write,
1355 	.get_dquots	= ext4_get_dquots,
1356 #endif
1357 	.bdev_try_to_free_page = bdev_try_to_free_page,
1358 };
1359 
1360 static const struct export_operations ext4_export_ops = {
1361 	.fh_to_dentry = ext4_fh_to_dentry,
1362 	.fh_to_parent = ext4_fh_to_parent,
1363 	.get_parent = ext4_get_parent,
1364 };
1365 
1366 enum {
1367 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1368 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1369 	Opt_nouid32, Opt_debug, Opt_removed,
1370 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1371 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1372 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1373 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1374 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1375 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1376 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1377 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1378 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1379 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1380 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1381 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1382 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1383 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1384 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1385 	Opt_dioread_nolock, Opt_dioread_lock,
1386 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1387 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1388 };
1389 
1390 static const match_table_t tokens = {
1391 	{Opt_bsd_df, "bsddf"},
1392 	{Opt_minix_df, "minixdf"},
1393 	{Opt_grpid, "grpid"},
1394 	{Opt_grpid, "bsdgroups"},
1395 	{Opt_nogrpid, "nogrpid"},
1396 	{Opt_nogrpid, "sysvgroups"},
1397 	{Opt_resgid, "resgid=%u"},
1398 	{Opt_resuid, "resuid=%u"},
1399 	{Opt_sb, "sb=%u"},
1400 	{Opt_err_cont, "errors=continue"},
1401 	{Opt_err_panic, "errors=panic"},
1402 	{Opt_err_ro, "errors=remount-ro"},
1403 	{Opt_nouid32, "nouid32"},
1404 	{Opt_debug, "debug"},
1405 	{Opt_removed, "oldalloc"},
1406 	{Opt_removed, "orlov"},
1407 	{Opt_user_xattr, "user_xattr"},
1408 	{Opt_nouser_xattr, "nouser_xattr"},
1409 	{Opt_acl, "acl"},
1410 	{Opt_noacl, "noacl"},
1411 	{Opt_noload, "norecovery"},
1412 	{Opt_noload, "noload"},
1413 	{Opt_removed, "nobh"},
1414 	{Opt_removed, "bh"},
1415 	{Opt_commit, "commit=%u"},
1416 	{Opt_min_batch_time, "min_batch_time=%u"},
1417 	{Opt_max_batch_time, "max_batch_time=%u"},
1418 	{Opt_journal_dev, "journal_dev=%u"},
1419 	{Opt_journal_path, "journal_path=%s"},
1420 	{Opt_journal_checksum, "journal_checksum"},
1421 	{Opt_nojournal_checksum, "nojournal_checksum"},
1422 	{Opt_journal_async_commit, "journal_async_commit"},
1423 	{Opt_abort, "abort"},
1424 	{Opt_data_journal, "data=journal"},
1425 	{Opt_data_ordered, "data=ordered"},
1426 	{Opt_data_writeback, "data=writeback"},
1427 	{Opt_data_err_abort, "data_err=abort"},
1428 	{Opt_data_err_ignore, "data_err=ignore"},
1429 	{Opt_offusrjquota, "usrjquota="},
1430 	{Opt_usrjquota, "usrjquota=%s"},
1431 	{Opt_offgrpjquota, "grpjquota="},
1432 	{Opt_grpjquota, "grpjquota=%s"},
1433 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1434 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1435 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1436 	{Opt_grpquota, "grpquota"},
1437 	{Opt_noquota, "noquota"},
1438 	{Opt_quota, "quota"},
1439 	{Opt_usrquota, "usrquota"},
1440 	{Opt_prjquota, "prjquota"},
1441 	{Opt_barrier, "barrier=%u"},
1442 	{Opt_barrier, "barrier"},
1443 	{Opt_nobarrier, "nobarrier"},
1444 	{Opt_i_version, "i_version"},
1445 	{Opt_dax, "dax"},
1446 	{Opt_stripe, "stripe=%u"},
1447 	{Opt_delalloc, "delalloc"},
1448 	{Opt_warn_on_error, "warn_on_error"},
1449 	{Opt_nowarn_on_error, "nowarn_on_error"},
1450 	{Opt_lazytime, "lazytime"},
1451 	{Opt_nolazytime, "nolazytime"},
1452 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1453 	{Opt_nodelalloc, "nodelalloc"},
1454 	{Opt_removed, "mblk_io_submit"},
1455 	{Opt_removed, "nomblk_io_submit"},
1456 	{Opt_block_validity, "block_validity"},
1457 	{Opt_noblock_validity, "noblock_validity"},
1458 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1459 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1460 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1461 	{Opt_auto_da_alloc, "auto_da_alloc"},
1462 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1463 	{Opt_dioread_nolock, "dioread_nolock"},
1464 	{Opt_dioread_lock, "dioread_lock"},
1465 	{Opt_discard, "discard"},
1466 	{Opt_nodiscard, "nodiscard"},
1467 	{Opt_init_itable, "init_itable=%u"},
1468 	{Opt_init_itable, "init_itable"},
1469 	{Opt_noinit_itable, "noinit_itable"},
1470 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1471 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1472 	{Opt_nombcache, "nombcache"},
1473 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1474 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1475 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1476 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1477 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1478 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1479 	{Opt_err, NULL},
1480 };
1481 
1482 static ext4_fsblk_t get_sb_block(void **data)
1483 {
1484 	ext4_fsblk_t	sb_block;
1485 	char		*options = (char *) *data;
1486 
1487 	if (!options || strncmp(options, "sb=", 3) != 0)
1488 		return 1;	/* Default location */
1489 
1490 	options += 3;
1491 	/* TODO: use simple_strtoll with >32bit ext4 */
1492 	sb_block = simple_strtoul(options, &options, 0);
1493 	if (*options && *options != ',') {
1494 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1495 		       (char *) *data);
1496 		return 1;
1497 	}
1498 	if (*options == ',')
1499 		options++;
1500 	*data = (void *) options;
1501 
1502 	return sb_block;
1503 }
1504 
1505 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1506 static const char deprecated_msg[] =
1507 	"Mount option \"%s\" will be removed by %s\n"
1508 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1509 
1510 #ifdef CONFIG_QUOTA
1511 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1512 {
1513 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1514 	char *qname;
1515 	int ret = -1;
1516 
1517 	if (sb_any_quota_loaded(sb) &&
1518 		!sbi->s_qf_names[qtype]) {
1519 		ext4_msg(sb, KERN_ERR,
1520 			"Cannot change journaled "
1521 			"quota options when quota turned on");
1522 		return -1;
1523 	}
1524 	if (ext4_has_feature_quota(sb)) {
1525 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1526 			 "ignored when QUOTA feature is enabled");
1527 		return 1;
1528 	}
1529 	qname = match_strdup(args);
1530 	if (!qname) {
1531 		ext4_msg(sb, KERN_ERR,
1532 			"Not enough memory for storing quotafile name");
1533 		return -1;
1534 	}
1535 	if (sbi->s_qf_names[qtype]) {
1536 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1537 			ret = 1;
1538 		else
1539 			ext4_msg(sb, KERN_ERR,
1540 				 "%s quota file already specified",
1541 				 QTYPE2NAME(qtype));
1542 		goto errout;
1543 	}
1544 	if (strchr(qname, '/')) {
1545 		ext4_msg(sb, KERN_ERR,
1546 			"quotafile must be on filesystem root");
1547 		goto errout;
1548 	}
1549 	sbi->s_qf_names[qtype] = qname;
1550 	set_opt(sb, QUOTA);
1551 	return 1;
1552 errout:
1553 	kfree(qname);
1554 	return ret;
1555 }
1556 
1557 static int clear_qf_name(struct super_block *sb, int qtype)
1558 {
1559 
1560 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1561 
1562 	if (sb_any_quota_loaded(sb) &&
1563 		sbi->s_qf_names[qtype]) {
1564 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1565 			" when quota turned on");
1566 		return -1;
1567 	}
1568 	kfree(sbi->s_qf_names[qtype]);
1569 	sbi->s_qf_names[qtype] = NULL;
1570 	return 1;
1571 }
1572 #endif
1573 
1574 #define MOPT_SET	0x0001
1575 #define MOPT_CLEAR	0x0002
1576 #define MOPT_NOSUPPORT	0x0004
1577 #define MOPT_EXPLICIT	0x0008
1578 #define MOPT_CLEAR_ERR	0x0010
1579 #define MOPT_GTE0	0x0020
1580 #ifdef CONFIG_QUOTA
1581 #define MOPT_Q		0
1582 #define MOPT_QFMT	0x0040
1583 #else
1584 #define MOPT_Q		MOPT_NOSUPPORT
1585 #define MOPT_QFMT	MOPT_NOSUPPORT
1586 #endif
1587 #define MOPT_DATAJ	0x0080
1588 #define MOPT_NO_EXT2	0x0100
1589 #define MOPT_NO_EXT3	0x0200
1590 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1591 #define MOPT_STRING	0x0400
1592 
1593 static const struct mount_opts {
1594 	int	token;
1595 	int	mount_opt;
1596 	int	flags;
1597 } ext4_mount_opts[] = {
1598 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1599 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1600 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1601 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1602 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1603 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1604 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1605 	 MOPT_EXT4_ONLY | MOPT_SET},
1606 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1607 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1608 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1609 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1610 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1611 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1612 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1613 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1614 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1615 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1616 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1617 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1618 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1619 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1620 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1621 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1622 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1623 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1624 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1625 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1626 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1627 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1628 	 MOPT_NO_EXT2},
1629 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1630 	 MOPT_NO_EXT2},
1631 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1632 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1633 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1634 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1635 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1636 	{Opt_commit, 0, MOPT_GTE0},
1637 	{Opt_max_batch_time, 0, MOPT_GTE0},
1638 	{Opt_min_batch_time, 0, MOPT_GTE0},
1639 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1640 	{Opt_init_itable, 0, MOPT_GTE0},
1641 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1642 	{Opt_stripe, 0, MOPT_GTE0},
1643 	{Opt_resuid, 0, MOPT_GTE0},
1644 	{Opt_resgid, 0, MOPT_GTE0},
1645 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1646 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1647 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1648 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1649 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1650 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1651 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1652 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1653 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1654 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1655 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1656 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1657 #else
1658 	{Opt_acl, 0, MOPT_NOSUPPORT},
1659 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1660 #endif
1661 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1662 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1663 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1664 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1665 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1666 							MOPT_SET | MOPT_Q},
1667 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1668 							MOPT_SET | MOPT_Q},
1669 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1670 							MOPT_SET | MOPT_Q},
1671 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1672 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1673 							MOPT_CLEAR | MOPT_Q},
1674 	{Opt_usrjquota, 0, MOPT_Q},
1675 	{Opt_grpjquota, 0, MOPT_Q},
1676 	{Opt_offusrjquota, 0, MOPT_Q},
1677 	{Opt_offgrpjquota, 0, MOPT_Q},
1678 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1679 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1680 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1681 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1682 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1683 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1684 	{Opt_err, 0, 0}
1685 };
1686 
1687 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1688 			    substring_t *args, unsigned long *journal_devnum,
1689 			    unsigned int *journal_ioprio, int is_remount)
1690 {
1691 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1692 	const struct mount_opts *m;
1693 	kuid_t uid;
1694 	kgid_t gid;
1695 	int arg = 0;
1696 
1697 #ifdef CONFIG_QUOTA
1698 	if (token == Opt_usrjquota)
1699 		return set_qf_name(sb, USRQUOTA, &args[0]);
1700 	else if (token == Opt_grpjquota)
1701 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1702 	else if (token == Opt_offusrjquota)
1703 		return clear_qf_name(sb, USRQUOTA);
1704 	else if (token == Opt_offgrpjquota)
1705 		return clear_qf_name(sb, GRPQUOTA);
1706 #endif
1707 	switch (token) {
1708 	case Opt_noacl:
1709 	case Opt_nouser_xattr:
1710 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1711 		break;
1712 	case Opt_sb:
1713 		return 1;	/* handled by get_sb_block() */
1714 	case Opt_removed:
1715 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1716 		return 1;
1717 	case Opt_abort:
1718 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1719 		return 1;
1720 	case Opt_i_version:
1721 		sb->s_flags |= SB_I_VERSION;
1722 		return 1;
1723 	case Opt_lazytime:
1724 		sb->s_flags |= SB_LAZYTIME;
1725 		return 1;
1726 	case Opt_nolazytime:
1727 		sb->s_flags &= ~SB_LAZYTIME;
1728 		return 1;
1729 	}
1730 
1731 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1732 		if (token == m->token)
1733 			break;
1734 
1735 	if (m->token == Opt_err) {
1736 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1737 			 "or missing value", opt);
1738 		return -1;
1739 	}
1740 
1741 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1742 		ext4_msg(sb, KERN_ERR,
1743 			 "Mount option \"%s\" incompatible with ext2", opt);
1744 		return -1;
1745 	}
1746 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1747 		ext4_msg(sb, KERN_ERR,
1748 			 "Mount option \"%s\" incompatible with ext3", opt);
1749 		return -1;
1750 	}
1751 
1752 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1753 		return -1;
1754 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1755 		return -1;
1756 	if (m->flags & MOPT_EXPLICIT) {
1757 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1758 			set_opt2(sb, EXPLICIT_DELALLOC);
1759 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1760 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1761 		} else
1762 			return -1;
1763 	}
1764 	if (m->flags & MOPT_CLEAR_ERR)
1765 		clear_opt(sb, ERRORS_MASK);
1766 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1767 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1768 			 "options when quota turned on");
1769 		return -1;
1770 	}
1771 
1772 	if (m->flags & MOPT_NOSUPPORT) {
1773 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1774 	} else if (token == Opt_commit) {
1775 		if (arg == 0)
1776 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1777 		sbi->s_commit_interval = HZ * arg;
1778 	} else if (token == Opt_debug_want_extra_isize) {
1779 		sbi->s_want_extra_isize = arg;
1780 	} else if (token == Opt_max_batch_time) {
1781 		sbi->s_max_batch_time = arg;
1782 	} else if (token == Opt_min_batch_time) {
1783 		sbi->s_min_batch_time = arg;
1784 	} else if (token == Opt_inode_readahead_blks) {
1785 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1786 			ext4_msg(sb, KERN_ERR,
1787 				 "EXT4-fs: inode_readahead_blks must be "
1788 				 "0 or a power of 2 smaller than 2^31");
1789 			return -1;
1790 		}
1791 		sbi->s_inode_readahead_blks = arg;
1792 	} else if (token == Opt_init_itable) {
1793 		set_opt(sb, INIT_INODE_TABLE);
1794 		if (!args->from)
1795 			arg = EXT4_DEF_LI_WAIT_MULT;
1796 		sbi->s_li_wait_mult = arg;
1797 	} else if (token == Opt_max_dir_size_kb) {
1798 		sbi->s_max_dir_size_kb = arg;
1799 	} else if (token == Opt_stripe) {
1800 		sbi->s_stripe = arg;
1801 	} else if (token == Opt_resuid) {
1802 		uid = make_kuid(current_user_ns(), arg);
1803 		if (!uid_valid(uid)) {
1804 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1805 			return -1;
1806 		}
1807 		sbi->s_resuid = uid;
1808 	} else if (token == Opt_resgid) {
1809 		gid = make_kgid(current_user_ns(), arg);
1810 		if (!gid_valid(gid)) {
1811 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1812 			return -1;
1813 		}
1814 		sbi->s_resgid = gid;
1815 	} else if (token == Opt_journal_dev) {
1816 		if (is_remount) {
1817 			ext4_msg(sb, KERN_ERR,
1818 				 "Cannot specify journal on remount");
1819 			return -1;
1820 		}
1821 		*journal_devnum = arg;
1822 	} else if (token == Opt_journal_path) {
1823 		char *journal_path;
1824 		struct inode *journal_inode;
1825 		struct path path;
1826 		int error;
1827 
1828 		if (is_remount) {
1829 			ext4_msg(sb, KERN_ERR,
1830 				 "Cannot specify journal on remount");
1831 			return -1;
1832 		}
1833 		journal_path = match_strdup(&args[0]);
1834 		if (!journal_path) {
1835 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1836 				"journal device string");
1837 			return -1;
1838 		}
1839 
1840 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1841 		if (error) {
1842 			ext4_msg(sb, KERN_ERR, "error: could not find "
1843 				"journal device path: error %d", error);
1844 			kfree(journal_path);
1845 			return -1;
1846 		}
1847 
1848 		journal_inode = d_inode(path.dentry);
1849 		if (!S_ISBLK(journal_inode->i_mode)) {
1850 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1851 				"is not a block device", journal_path);
1852 			path_put(&path);
1853 			kfree(journal_path);
1854 			return -1;
1855 		}
1856 
1857 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1858 		path_put(&path);
1859 		kfree(journal_path);
1860 	} else if (token == Opt_journal_ioprio) {
1861 		if (arg > 7) {
1862 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1863 				 " (must be 0-7)");
1864 			return -1;
1865 		}
1866 		*journal_ioprio =
1867 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1868 	} else if (token == Opt_test_dummy_encryption) {
1869 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1870 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1871 		ext4_msg(sb, KERN_WARNING,
1872 			 "Test dummy encryption mode enabled");
1873 #else
1874 		ext4_msg(sb, KERN_WARNING,
1875 			 "Test dummy encryption mount option ignored");
1876 #endif
1877 	} else if (m->flags & MOPT_DATAJ) {
1878 		if (is_remount) {
1879 			if (!sbi->s_journal)
1880 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1881 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1882 				ext4_msg(sb, KERN_ERR,
1883 					 "Cannot change data mode on remount");
1884 				return -1;
1885 			}
1886 		} else {
1887 			clear_opt(sb, DATA_FLAGS);
1888 			sbi->s_mount_opt |= m->mount_opt;
1889 		}
1890 #ifdef CONFIG_QUOTA
1891 	} else if (m->flags & MOPT_QFMT) {
1892 		if (sb_any_quota_loaded(sb) &&
1893 		    sbi->s_jquota_fmt != m->mount_opt) {
1894 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1895 				 "quota options when quota turned on");
1896 			return -1;
1897 		}
1898 		if (ext4_has_feature_quota(sb)) {
1899 			ext4_msg(sb, KERN_INFO,
1900 				 "Quota format mount options ignored "
1901 				 "when QUOTA feature is enabled");
1902 			return 1;
1903 		}
1904 		sbi->s_jquota_fmt = m->mount_opt;
1905 #endif
1906 	} else if (token == Opt_dax) {
1907 #ifdef CONFIG_FS_DAX
1908 		ext4_msg(sb, KERN_WARNING,
1909 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1910 			sbi->s_mount_opt |= m->mount_opt;
1911 #else
1912 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1913 		return -1;
1914 #endif
1915 	} else if (token == Opt_data_err_abort) {
1916 		sbi->s_mount_opt |= m->mount_opt;
1917 	} else if (token == Opt_data_err_ignore) {
1918 		sbi->s_mount_opt &= ~m->mount_opt;
1919 	} else {
1920 		if (!args->from)
1921 			arg = 1;
1922 		if (m->flags & MOPT_CLEAR)
1923 			arg = !arg;
1924 		else if (unlikely(!(m->flags & MOPT_SET))) {
1925 			ext4_msg(sb, KERN_WARNING,
1926 				 "buggy handling of option %s", opt);
1927 			WARN_ON(1);
1928 			return -1;
1929 		}
1930 		if (arg != 0)
1931 			sbi->s_mount_opt |= m->mount_opt;
1932 		else
1933 			sbi->s_mount_opt &= ~m->mount_opt;
1934 	}
1935 	return 1;
1936 }
1937 
1938 static int parse_options(char *options, struct super_block *sb,
1939 			 unsigned long *journal_devnum,
1940 			 unsigned int *journal_ioprio,
1941 			 int is_remount)
1942 {
1943 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1944 	char *p;
1945 	substring_t args[MAX_OPT_ARGS];
1946 	int token;
1947 
1948 	if (!options)
1949 		return 1;
1950 
1951 	while ((p = strsep(&options, ",")) != NULL) {
1952 		if (!*p)
1953 			continue;
1954 		/*
1955 		 * Initialize args struct so we know whether arg was
1956 		 * found; some options take optional arguments.
1957 		 */
1958 		args[0].to = args[0].from = NULL;
1959 		token = match_token(p, tokens, args);
1960 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1961 				     journal_ioprio, is_remount) < 0)
1962 			return 0;
1963 	}
1964 #ifdef CONFIG_QUOTA
1965 	/*
1966 	 * We do the test below only for project quotas. 'usrquota' and
1967 	 * 'grpquota' mount options are allowed even without quota feature
1968 	 * to support legacy quotas in quota files.
1969 	 */
1970 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1971 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1972 			 "Cannot enable project quota enforcement.");
1973 		return 0;
1974 	}
1975 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1976 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1977 			clear_opt(sb, USRQUOTA);
1978 
1979 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1980 			clear_opt(sb, GRPQUOTA);
1981 
1982 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1983 			ext4_msg(sb, KERN_ERR, "old and new quota "
1984 					"format mixing");
1985 			return 0;
1986 		}
1987 
1988 		if (!sbi->s_jquota_fmt) {
1989 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1990 					"not specified");
1991 			return 0;
1992 		}
1993 	}
1994 #endif
1995 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1996 		int blocksize =
1997 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1998 
1999 		if (blocksize < PAGE_SIZE) {
2000 			ext4_msg(sb, KERN_ERR, "can't mount with "
2001 				 "dioread_nolock if block size != PAGE_SIZE");
2002 			return 0;
2003 		}
2004 	}
2005 	return 1;
2006 }
2007 
2008 static inline void ext4_show_quota_options(struct seq_file *seq,
2009 					   struct super_block *sb)
2010 {
2011 #if defined(CONFIG_QUOTA)
2012 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2013 
2014 	if (sbi->s_jquota_fmt) {
2015 		char *fmtname = "";
2016 
2017 		switch (sbi->s_jquota_fmt) {
2018 		case QFMT_VFS_OLD:
2019 			fmtname = "vfsold";
2020 			break;
2021 		case QFMT_VFS_V0:
2022 			fmtname = "vfsv0";
2023 			break;
2024 		case QFMT_VFS_V1:
2025 			fmtname = "vfsv1";
2026 			break;
2027 		}
2028 		seq_printf(seq, ",jqfmt=%s", fmtname);
2029 	}
2030 
2031 	if (sbi->s_qf_names[USRQUOTA])
2032 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
2033 
2034 	if (sbi->s_qf_names[GRPQUOTA])
2035 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
2036 #endif
2037 }
2038 
2039 static const char *token2str(int token)
2040 {
2041 	const struct match_token *t;
2042 
2043 	for (t = tokens; t->token != Opt_err; t++)
2044 		if (t->token == token && !strchr(t->pattern, '='))
2045 			break;
2046 	return t->pattern;
2047 }
2048 
2049 /*
2050  * Show an option if
2051  *  - it's set to a non-default value OR
2052  *  - if the per-sb default is different from the global default
2053  */
2054 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2055 			      int nodefs)
2056 {
2057 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2058 	struct ext4_super_block *es = sbi->s_es;
2059 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2060 	const struct mount_opts *m;
2061 	char sep = nodefs ? '\n' : ',';
2062 
2063 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2064 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2065 
2066 	if (sbi->s_sb_block != 1)
2067 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2068 
2069 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2070 		int want_set = m->flags & MOPT_SET;
2071 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2072 		    (m->flags & MOPT_CLEAR_ERR))
2073 			continue;
2074 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2075 			continue; /* skip if same as the default */
2076 		if ((want_set &&
2077 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2078 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2079 			continue; /* select Opt_noFoo vs Opt_Foo */
2080 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2081 	}
2082 
2083 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2084 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2085 		SEQ_OPTS_PRINT("resuid=%u",
2086 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2087 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2088 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2089 		SEQ_OPTS_PRINT("resgid=%u",
2090 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2091 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2092 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2093 		SEQ_OPTS_PUTS("errors=remount-ro");
2094 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2095 		SEQ_OPTS_PUTS("errors=continue");
2096 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2097 		SEQ_OPTS_PUTS("errors=panic");
2098 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2099 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2100 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2101 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2102 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2103 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2104 	if (sb->s_flags & SB_I_VERSION)
2105 		SEQ_OPTS_PUTS("i_version");
2106 	if (nodefs || sbi->s_stripe)
2107 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2108 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2109 			(sbi->s_mount_opt ^ def_mount_opt)) {
2110 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2111 			SEQ_OPTS_PUTS("data=journal");
2112 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2113 			SEQ_OPTS_PUTS("data=ordered");
2114 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2115 			SEQ_OPTS_PUTS("data=writeback");
2116 	}
2117 	if (nodefs ||
2118 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2119 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2120 			       sbi->s_inode_readahead_blks);
2121 
2122 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2123 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2124 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2125 	if (nodefs || sbi->s_max_dir_size_kb)
2126 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2127 	if (test_opt(sb, DATA_ERR_ABORT))
2128 		SEQ_OPTS_PUTS("data_err=abort");
2129 
2130 	ext4_show_quota_options(seq, sb);
2131 	return 0;
2132 }
2133 
2134 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2135 {
2136 	return _ext4_show_options(seq, root->d_sb, 0);
2137 }
2138 
2139 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2140 {
2141 	struct super_block *sb = seq->private;
2142 	int rc;
2143 
2144 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2145 	rc = _ext4_show_options(seq, sb, 1);
2146 	seq_puts(seq, "\n");
2147 	return rc;
2148 }
2149 
2150 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2151 			    int read_only)
2152 {
2153 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2154 	int err = 0;
2155 
2156 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2157 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2158 			 "forcing read-only mode");
2159 		err = -EROFS;
2160 	}
2161 	if (read_only)
2162 		goto done;
2163 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2164 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2165 			 "running e2fsck is recommended");
2166 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2167 		ext4_msg(sb, KERN_WARNING,
2168 			 "warning: mounting fs with errors, "
2169 			 "running e2fsck is recommended");
2170 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2171 		 le16_to_cpu(es->s_mnt_count) >=
2172 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2173 		ext4_msg(sb, KERN_WARNING,
2174 			 "warning: maximal mount count reached, "
2175 			 "running e2fsck is recommended");
2176 	else if (le32_to_cpu(es->s_checkinterval) &&
2177 		(le32_to_cpu(es->s_lastcheck) +
2178 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2179 		ext4_msg(sb, KERN_WARNING,
2180 			 "warning: checktime reached, "
2181 			 "running e2fsck is recommended");
2182 	if (!sbi->s_journal)
2183 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2184 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2185 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2186 	le16_add_cpu(&es->s_mnt_count, 1);
2187 	es->s_mtime = cpu_to_le32(get_seconds());
2188 	ext4_update_dynamic_rev(sb);
2189 	if (sbi->s_journal)
2190 		ext4_set_feature_journal_needs_recovery(sb);
2191 
2192 	err = ext4_commit_super(sb, 1);
2193 done:
2194 	if (test_opt(sb, DEBUG))
2195 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2196 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2197 			sb->s_blocksize,
2198 			sbi->s_groups_count,
2199 			EXT4_BLOCKS_PER_GROUP(sb),
2200 			EXT4_INODES_PER_GROUP(sb),
2201 			sbi->s_mount_opt, sbi->s_mount_opt2);
2202 
2203 	cleancache_init_fs(sb);
2204 	return err;
2205 }
2206 
2207 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2208 {
2209 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2210 	struct flex_groups *new_groups;
2211 	int size;
2212 
2213 	if (!sbi->s_log_groups_per_flex)
2214 		return 0;
2215 
2216 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2217 	if (size <= sbi->s_flex_groups_allocated)
2218 		return 0;
2219 
2220 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2221 	new_groups = kvzalloc(size, GFP_KERNEL);
2222 	if (!new_groups) {
2223 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2224 			 size / (int) sizeof(struct flex_groups));
2225 		return -ENOMEM;
2226 	}
2227 
2228 	if (sbi->s_flex_groups) {
2229 		memcpy(new_groups, sbi->s_flex_groups,
2230 		       (sbi->s_flex_groups_allocated *
2231 			sizeof(struct flex_groups)));
2232 		kvfree(sbi->s_flex_groups);
2233 	}
2234 	sbi->s_flex_groups = new_groups;
2235 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2236 	return 0;
2237 }
2238 
2239 static int ext4_fill_flex_info(struct super_block *sb)
2240 {
2241 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2242 	struct ext4_group_desc *gdp = NULL;
2243 	ext4_group_t flex_group;
2244 	int i, err;
2245 
2246 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2247 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2248 		sbi->s_log_groups_per_flex = 0;
2249 		return 1;
2250 	}
2251 
2252 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2253 	if (err)
2254 		goto failed;
2255 
2256 	for (i = 0; i < sbi->s_groups_count; i++) {
2257 		gdp = ext4_get_group_desc(sb, i, NULL);
2258 
2259 		flex_group = ext4_flex_group(sbi, i);
2260 		atomic_add(ext4_free_inodes_count(sb, gdp),
2261 			   &sbi->s_flex_groups[flex_group].free_inodes);
2262 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2263 			     &sbi->s_flex_groups[flex_group].free_clusters);
2264 		atomic_add(ext4_used_dirs_count(sb, gdp),
2265 			   &sbi->s_flex_groups[flex_group].used_dirs);
2266 	}
2267 
2268 	return 1;
2269 failed:
2270 	return 0;
2271 }
2272 
2273 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2274 				   struct ext4_group_desc *gdp)
2275 {
2276 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2277 	__u16 crc = 0;
2278 	__le32 le_group = cpu_to_le32(block_group);
2279 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2280 
2281 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2282 		/* Use new metadata_csum algorithm */
2283 		__u32 csum32;
2284 		__u16 dummy_csum = 0;
2285 
2286 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2287 				     sizeof(le_group));
2288 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2289 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2290 				     sizeof(dummy_csum));
2291 		offset += sizeof(dummy_csum);
2292 		if (offset < sbi->s_desc_size)
2293 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2294 					     sbi->s_desc_size - offset);
2295 
2296 		crc = csum32 & 0xFFFF;
2297 		goto out;
2298 	}
2299 
2300 	/* old crc16 code */
2301 	if (!ext4_has_feature_gdt_csum(sb))
2302 		return 0;
2303 
2304 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2305 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2306 	crc = crc16(crc, (__u8 *)gdp, offset);
2307 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2308 	/* for checksum of struct ext4_group_desc do the rest...*/
2309 	if (ext4_has_feature_64bit(sb) &&
2310 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2311 		crc = crc16(crc, (__u8 *)gdp + offset,
2312 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2313 				offset);
2314 
2315 out:
2316 	return cpu_to_le16(crc);
2317 }
2318 
2319 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2320 				struct ext4_group_desc *gdp)
2321 {
2322 	if (ext4_has_group_desc_csum(sb) &&
2323 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2324 		return 0;
2325 
2326 	return 1;
2327 }
2328 
2329 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2330 			      struct ext4_group_desc *gdp)
2331 {
2332 	if (!ext4_has_group_desc_csum(sb))
2333 		return;
2334 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2335 }
2336 
2337 /* Called at mount-time, super-block is locked */
2338 static int ext4_check_descriptors(struct super_block *sb,
2339 				  ext4_fsblk_t sb_block,
2340 				  ext4_group_t *first_not_zeroed)
2341 {
2342 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2343 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2344 	ext4_fsblk_t last_block;
2345 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0) + 1;
2346 	ext4_fsblk_t block_bitmap;
2347 	ext4_fsblk_t inode_bitmap;
2348 	ext4_fsblk_t inode_table;
2349 	int flexbg_flag = 0;
2350 	ext4_group_t i, grp = sbi->s_groups_count;
2351 
2352 	if (ext4_has_feature_flex_bg(sb))
2353 		flexbg_flag = 1;
2354 
2355 	ext4_debug("Checking group descriptors");
2356 
2357 	for (i = 0; i < sbi->s_groups_count; i++) {
2358 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2359 
2360 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2361 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2362 		else
2363 			last_block = first_block +
2364 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2365 
2366 		if ((grp == sbi->s_groups_count) &&
2367 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2368 			grp = i;
2369 
2370 		block_bitmap = ext4_block_bitmap(sb, gdp);
2371 		if (block_bitmap == sb_block) {
2372 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2373 				 "Block bitmap for group %u overlaps "
2374 				 "superblock", i);
2375 			if (!sb_rdonly(sb))
2376 				return 0;
2377 		}
2378 		if (block_bitmap >= sb_block + 1 &&
2379 		    block_bitmap <= last_bg_block) {
2380 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2381 				 "Block bitmap for group %u overlaps "
2382 				 "block group descriptors", i);
2383 			if (!sb_rdonly(sb))
2384 				return 0;
2385 		}
2386 		if (block_bitmap < first_block || block_bitmap > last_block) {
2387 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2388 			       "Block bitmap for group %u not in group "
2389 			       "(block %llu)!", i, block_bitmap);
2390 			return 0;
2391 		}
2392 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2393 		if (inode_bitmap == sb_block) {
2394 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2395 				 "Inode bitmap for group %u overlaps "
2396 				 "superblock", i);
2397 			if (!sb_rdonly(sb))
2398 				return 0;
2399 		}
2400 		if (inode_bitmap >= sb_block + 1 &&
2401 		    inode_bitmap <= last_bg_block) {
2402 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2403 				 "Inode bitmap for group %u overlaps "
2404 				 "block group descriptors", i);
2405 			if (!sb_rdonly(sb))
2406 				return 0;
2407 		}
2408 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2409 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2410 			       "Inode bitmap for group %u not in group "
2411 			       "(block %llu)!", i, inode_bitmap);
2412 			return 0;
2413 		}
2414 		inode_table = ext4_inode_table(sb, gdp);
2415 		if (inode_table == sb_block) {
2416 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2417 				 "Inode table for group %u overlaps "
2418 				 "superblock", i);
2419 			if (!sb_rdonly(sb))
2420 				return 0;
2421 		}
2422 		if (inode_table >= sb_block + 1 &&
2423 		    inode_table <= last_bg_block) {
2424 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2425 				 "Inode table for group %u overlaps "
2426 				 "block group descriptors", i);
2427 			if (!sb_rdonly(sb))
2428 				return 0;
2429 		}
2430 		if (inode_table < first_block ||
2431 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2432 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2433 			       "Inode table for group %u not in group "
2434 			       "(block %llu)!", i, inode_table);
2435 			return 0;
2436 		}
2437 		ext4_lock_group(sb, i);
2438 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2439 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2440 				 "Checksum for group %u failed (%u!=%u)",
2441 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2442 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2443 			if (!sb_rdonly(sb)) {
2444 				ext4_unlock_group(sb, i);
2445 				return 0;
2446 			}
2447 		}
2448 		ext4_unlock_group(sb, i);
2449 		if (!flexbg_flag)
2450 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2451 	}
2452 	if (NULL != first_not_zeroed)
2453 		*first_not_zeroed = grp;
2454 	return 1;
2455 }
2456 
2457 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2458  * the superblock) which were deleted from all directories, but held open by
2459  * a process at the time of a crash.  We walk the list and try to delete these
2460  * inodes at recovery time (only with a read-write filesystem).
2461  *
2462  * In order to keep the orphan inode chain consistent during traversal (in
2463  * case of crash during recovery), we link each inode into the superblock
2464  * orphan list_head and handle it the same way as an inode deletion during
2465  * normal operation (which journals the operations for us).
2466  *
2467  * We only do an iget() and an iput() on each inode, which is very safe if we
2468  * accidentally point at an in-use or already deleted inode.  The worst that
2469  * can happen in this case is that we get a "bit already cleared" message from
2470  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2471  * e2fsck was run on this filesystem, and it must have already done the orphan
2472  * inode cleanup for us, so we can safely abort without any further action.
2473  */
2474 static void ext4_orphan_cleanup(struct super_block *sb,
2475 				struct ext4_super_block *es)
2476 {
2477 	unsigned int s_flags = sb->s_flags;
2478 	int ret, nr_orphans = 0, nr_truncates = 0;
2479 #ifdef CONFIG_QUOTA
2480 	int quota_update = 0;
2481 	int i;
2482 #endif
2483 	if (!es->s_last_orphan) {
2484 		jbd_debug(4, "no orphan inodes to clean up\n");
2485 		return;
2486 	}
2487 
2488 	if (bdev_read_only(sb->s_bdev)) {
2489 		ext4_msg(sb, KERN_ERR, "write access "
2490 			"unavailable, skipping orphan cleanup");
2491 		return;
2492 	}
2493 
2494 	/* Check if feature set would not allow a r/w mount */
2495 	if (!ext4_feature_set_ok(sb, 0)) {
2496 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2497 			 "unknown ROCOMPAT features");
2498 		return;
2499 	}
2500 
2501 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2502 		/* don't clear list on RO mount w/ errors */
2503 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2504 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2505 				  "clearing orphan list.\n");
2506 			es->s_last_orphan = 0;
2507 		}
2508 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2509 		return;
2510 	}
2511 
2512 	if (s_flags & SB_RDONLY) {
2513 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2514 		sb->s_flags &= ~SB_RDONLY;
2515 	}
2516 #ifdef CONFIG_QUOTA
2517 	/* Needed for iput() to work correctly and not trash data */
2518 	sb->s_flags |= SB_ACTIVE;
2519 
2520 	/*
2521 	 * Turn on quotas which were not enabled for read-only mounts if
2522 	 * filesystem has quota feature, so that they are updated correctly.
2523 	 */
2524 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2525 		int ret = ext4_enable_quotas(sb);
2526 
2527 		if (!ret)
2528 			quota_update = 1;
2529 		else
2530 			ext4_msg(sb, KERN_ERR,
2531 				"Cannot turn on quotas: error %d", ret);
2532 	}
2533 
2534 	/* Turn on journaled quotas used for old sytle */
2535 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2536 		if (EXT4_SB(sb)->s_qf_names[i]) {
2537 			int ret = ext4_quota_on_mount(sb, i);
2538 
2539 			if (!ret)
2540 				quota_update = 1;
2541 			else
2542 				ext4_msg(sb, KERN_ERR,
2543 					"Cannot turn on journaled "
2544 					"quota: type %d: error %d", i, ret);
2545 		}
2546 	}
2547 #endif
2548 
2549 	while (es->s_last_orphan) {
2550 		struct inode *inode;
2551 
2552 		/*
2553 		 * We may have encountered an error during cleanup; if
2554 		 * so, skip the rest.
2555 		 */
2556 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2557 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2558 			es->s_last_orphan = 0;
2559 			break;
2560 		}
2561 
2562 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2563 		if (IS_ERR(inode)) {
2564 			es->s_last_orphan = 0;
2565 			break;
2566 		}
2567 
2568 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2569 		dquot_initialize(inode);
2570 		if (inode->i_nlink) {
2571 			if (test_opt(sb, DEBUG))
2572 				ext4_msg(sb, KERN_DEBUG,
2573 					"%s: truncating inode %lu to %lld bytes",
2574 					__func__, inode->i_ino, inode->i_size);
2575 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2576 				  inode->i_ino, inode->i_size);
2577 			inode_lock(inode);
2578 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2579 			ret = ext4_truncate(inode);
2580 			if (ret)
2581 				ext4_std_error(inode->i_sb, ret);
2582 			inode_unlock(inode);
2583 			nr_truncates++;
2584 		} else {
2585 			if (test_opt(sb, DEBUG))
2586 				ext4_msg(sb, KERN_DEBUG,
2587 					"%s: deleting unreferenced inode %lu",
2588 					__func__, inode->i_ino);
2589 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2590 				  inode->i_ino);
2591 			nr_orphans++;
2592 		}
2593 		iput(inode);  /* The delete magic happens here! */
2594 	}
2595 
2596 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2597 
2598 	if (nr_orphans)
2599 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2600 		       PLURAL(nr_orphans));
2601 	if (nr_truncates)
2602 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2603 		       PLURAL(nr_truncates));
2604 #ifdef CONFIG_QUOTA
2605 	/* Turn off quotas if they were enabled for orphan cleanup */
2606 	if (quota_update) {
2607 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2608 			if (sb_dqopt(sb)->files[i])
2609 				dquot_quota_off(sb, i);
2610 		}
2611 	}
2612 #endif
2613 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2614 }
2615 
2616 /*
2617  * Maximal extent format file size.
2618  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2619  * extent format containers, within a sector_t, and within i_blocks
2620  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2621  * so that won't be a limiting factor.
2622  *
2623  * However there is other limiting factor. We do store extents in the form
2624  * of starting block and length, hence the resulting length of the extent
2625  * covering maximum file size must fit into on-disk format containers as
2626  * well. Given that length is always by 1 unit bigger than max unit (because
2627  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2628  *
2629  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2630  */
2631 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2632 {
2633 	loff_t res;
2634 	loff_t upper_limit = MAX_LFS_FILESIZE;
2635 
2636 	/* small i_blocks in vfs inode? */
2637 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2638 		/*
2639 		 * CONFIG_LBDAF is not enabled implies the inode
2640 		 * i_block represent total blocks in 512 bytes
2641 		 * 32 == size of vfs inode i_blocks * 8
2642 		 */
2643 		upper_limit = (1LL << 32) - 1;
2644 
2645 		/* total blocks in file system block size */
2646 		upper_limit >>= (blkbits - 9);
2647 		upper_limit <<= blkbits;
2648 	}
2649 
2650 	/*
2651 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2652 	 * by one fs block, so ee_len can cover the extent of maximum file
2653 	 * size
2654 	 */
2655 	res = (1LL << 32) - 1;
2656 	res <<= blkbits;
2657 
2658 	/* Sanity check against vm- & vfs- imposed limits */
2659 	if (res > upper_limit)
2660 		res = upper_limit;
2661 
2662 	return res;
2663 }
2664 
2665 /*
2666  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2667  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2668  * We need to be 1 filesystem block less than the 2^48 sector limit.
2669  */
2670 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2671 {
2672 	loff_t res = EXT4_NDIR_BLOCKS;
2673 	int meta_blocks;
2674 	loff_t upper_limit;
2675 	/* This is calculated to be the largest file size for a dense, block
2676 	 * mapped file such that the file's total number of 512-byte sectors,
2677 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2678 	 *
2679 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2680 	 * number of 512-byte sectors of the file.
2681 	 */
2682 
2683 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2684 		/*
2685 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2686 		 * the inode i_block field represents total file blocks in
2687 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2688 		 */
2689 		upper_limit = (1LL << 32) - 1;
2690 
2691 		/* total blocks in file system block size */
2692 		upper_limit >>= (bits - 9);
2693 
2694 	} else {
2695 		/*
2696 		 * We use 48 bit ext4_inode i_blocks
2697 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2698 		 * represent total number of blocks in
2699 		 * file system block size
2700 		 */
2701 		upper_limit = (1LL << 48) - 1;
2702 
2703 	}
2704 
2705 	/* indirect blocks */
2706 	meta_blocks = 1;
2707 	/* double indirect blocks */
2708 	meta_blocks += 1 + (1LL << (bits-2));
2709 	/* tripple indirect blocks */
2710 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2711 
2712 	upper_limit -= meta_blocks;
2713 	upper_limit <<= bits;
2714 
2715 	res += 1LL << (bits-2);
2716 	res += 1LL << (2*(bits-2));
2717 	res += 1LL << (3*(bits-2));
2718 	res <<= bits;
2719 	if (res > upper_limit)
2720 		res = upper_limit;
2721 
2722 	if (res > MAX_LFS_FILESIZE)
2723 		res = MAX_LFS_FILESIZE;
2724 
2725 	return res;
2726 }
2727 
2728 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2729 				   ext4_fsblk_t logical_sb_block, int nr)
2730 {
2731 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2732 	ext4_group_t bg, first_meta_bg;
2733 	int has_super = 0;
2734 
2735 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2736 
2737 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2738 		return logical_sb_block + nr + 1;
2739 	bg = sbi->s_desc_per_block * nr;
2740 	if (ext4_bg_has_super(sb, bg))
2741 		has_super = 1;
2742 
2743 	/*
2744 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2745 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2746 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2747 	 * compensate.
2748 	 */
2749 	if (sb->s_blocksize == 1024 && nr == 0 &&
2750 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2751 		has_super++;
2752 
2753 	return (has_super + ext4_group_first_block_no(sb, bg));
2754 }
2755 
2756 /**
2757  * ext4_get_stripe_size: Get the stripe size.
2758  * @sbi: In memory super block info
2759  *
2760  * If we have specified it via mount option, then
2761  * use the mount option value. If the value specified at mount time is
2762  * greater than the blocks per group use the super block value.
2763  * If the super block value is greater than blocks per group return 0.
2764  * Allocator needs it be less than blocks per group.
2765  *
2766  */
2767 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2768 {
2769 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2770 	unsigned long stripe_width =
2771 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2772 	int ret;
2773 
2774 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2775 		ret = sbi->s_stripe;
2776 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2777 		ret = stripe_width;
2778 	else if (stride && stride <= sbi->s_blocks_per_group)
2779 		ret = stride;
2780 	else
2781 		ret = 0;
2782 
2783 	/*
2784 	 * If the stripe width is 1, this makes no sense and
2785 	 * we set it to 0 to turn off stripe handling code.
2786 	 */
2787 	if (ret <= 1)
2788 		ret = 0;
2789 
2790 	return ret;
2791 }
2792 
2793 /*
2794  * Check whether this filesystem can be mounted based on
2795  * the features present and the RDONLY/RDWR mount requested.
2796  * Returns 1 if this filesystem can be mounted as requested,
2797  * 0 if it cannot be.
2798  */
2799 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2800 {
2801 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2802 		ext4_msg(sb, KERN_ERR,
2803 			"Couldn't mount because of "
2804 			"unsupported optional features (%x)",
2805 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2806 			~EXT4_FEATURE_INCOMPAT_SUPP));
2807 		return 0;
2808 	}
2809 
2810 	if (readonly)
2811 		return 1;
2812 
2813 	if (ext4_has_feature_readonly(sb)) {
2814 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2815 		sb->s_flags |= SB_RDONLY;
2816 		return 1;
2817 	}
2818 
2819 	/* Check that feature set is OK for a read-write mount */
2820 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2821 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2822 			 "unsupported optional features (%x)",
2823 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2824 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2825 		return 0;
2826 	}
2827 	/*
2828 	 * Large file size enabled file system can only be mounted
2829 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2830 	 */
2831 	if (ext4_has_feature_huge_file(sb)) {
2832 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2833 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2834 				 "cannot be mounted RDWR without "
2835 				 "CONFIG_LBDAF");
2836 			return 0;
2837 		}
2838 	}
2839 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2840 		ext4_msg(sb, KERN_ERR,
2841 			 "Can't support bigalloc feature without "
2842 			 "extents feature\n");
2843 		return 0;
2844 	}
2845 
2846 #ifndef CONFIG_QUOTA
2847 	if (ext4_has_feature_quota(sb) && !readonly) {
2848 		ext4_msg(sb, KERN_ERR,
2849 			 "Filesystem with quota feature cannot be mounted RDWR "
2850 			 "without CONFIG_QUOTA");
2851 		return 0;
2852 	}
2853 	if (ext4_has_feature_project(sb) && !readonly) {
2854 		ext4_msg(sb, KERN_ERR,
2855 			 "Filesystem with project quota feature cannot be mounted RDWR "
2856 			 "without CONFIG_QUOTA");
2857 		return 0;
2858 	}
2859 #endif  /* CONFIG_QUOTA */
2860 	return 1;
2861 }
2862 
2863 /*
2864  * This function is called once a day if we have errors logged
2865  * on the file system
2866  */
2867 static void print_daily_error_info(struct timer_list *t)
2868 {
2869 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2870 	struct super_block *sb = sbi->s_sb;
2871 	struct ext4_super_block *es = sbi->s_es;
2872 
2873 	if (es->s_error_count)
2874 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2875 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2876 			 le32_to_cpu(es->s_error_count));
2877 	if (es->s_first_error_time) {
2878 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2879 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2880 		       (int) sizeof(es->s_first_error_func),
2881 		       es->s_first_error_func,
2882 		       le32_to_cpu(es->s_first_error_line));
2883 		if (es->s_first_error_ino)
2884 			printk(KERN_CONT ": inode %u",
2885 			       le32_to_cpu(es->s_first_error_ino));
2886 		if (es->s_first_error_block)
2887 			printk(KERN_CONT ": block %llu", (unsigned long long)
2888 			       le64_to_cpu(es->s_first_error_block));
2889 		printk(KERN_CONT "\n");
2890 	}
2891 	if (es->s_last_error_time) {
2892 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2893 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2894 		       (int) sizeof(es->s_last_error_func),
2895 		       es->s_last_error_func,
2896 		       le32_to_cpu(es->s_last_error_line));
2897 		if (es->s_last_error_ino)
2898 			printk(KERN_CONT ": inode %u",
2899 			       le32_to_cpu(es->s_last_error_ino));
2900 		if (es->s_last_error_block)
2901 			printk(KERN_CONT ": block %llu", (unsigned long long)
2902 			       le64_to_cpu(es->s_last_error_block));
2903 		printk(KERN_CONT "\n");
2904 	}
2905 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2906 }
2907 
2908 /* Find next suitable group and run ext4_init_inode_table */
2909 static int ext4_run_li_request(struct ext4_li_request *elr)
2910 {
2911 	struct ext4_group_desc *gdp = NULL;
2912 	ext4_group_t group, ngroups;
2913 	struct super_block *sb;
2914 	unsigned long timeout = 0;
2915 	int ret = 0;
2916 
2917 	sb = elr->lr_super;
2918 	ngroups = EXT4_SB(sb)->s_groups_count;
2919 
2920 	for (group = elr->lr_next_group; group < ngroups; group++) {
2921 		gdp = ext4_get_group_desc(sb, group, NULL);
2922 		if (!gdp) {
2923 			ret = 1;
2924 			break;
2925 		}
2926 
2927 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2928 			break;
2929 	}
2930 
2931 	if (group >= ngroups)
2932 		ret = 1;
2933 
2934 	if (!ret) {
2935 		timeout = jiffies;
2936 		ret = ext4_init_inode_table(sb, group,
2937 					    elr->lr_timeout ? 0 : 1);
2938 		if (elr->lr_timeout == 0) {
2939 			timeout = (jiffies - timeout) *
2940 				  elr->lr_sbi->s_li_wait_mult;
2941 			elr->lr_timeout = timeout;
2942 		}
2943 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2944 		elr->lr_next_group = group + 1;
2945 	}
2946 	return ret;
2947 }
2948 
2949 /*
2950  * Remove lr_request from the list_request and free the
2951  * request structure. Should be called with li_list_mtx held
2952  */
2953 static void ext4_remove_li_request(struct ext4_li_request *elr)
2954 {
2955 	struct ext4_sb_info *sbi;
2956 
2957 	if (!elr)
2958 		return;
2959 
2960 	sbi = elr->lr_sbi;
2961 
2962 	list_del(&elr->lr_request);
2963 	sbi->s_li_request = NULL;
2964 	kfree(elr);
2965 }
2966 
2967 static void ext4_unregister_li_request(struct super_block *sb)
2968 {
2969 	mutex_lock(&ext4_li_mtx);
2970 	if (!ext4_li_info) {
2971 		mutex_unlock(&ext4_li_mtx);
2972 		return;
2973 	}
2974 
2975 	mutex_lock(&ext4_li_info->li_list_mtx);
2976 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2977 	mutex_unlock(&ext4_li_info->li_list_mtx);
2978 	mutex_unlock(&ext4_li_mtx);
2979 }
2980 
2981 static struct task_struct *ext4_lazyinit_task;
2982 
2983 /*
2984  * This is the function where ext4lazyinit thread lives. It walks
2985  * through the request list searching for next scheduled filesystem.
2986  * When such a fs is found, run the lazy initialization request
2987  * (ext4_rn_li_request) and keep track of the time spend in this
2988  * function. Based on that time we compute next schedule time of
2989  * the request. When walking through the list is complete, compute
2990  * next waking time and put itself into sleep.
2991  */
2992 static int ext4_lazyinit_thread(void *arg)
2993 {
2994 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2995 	struct list_head *pos, *n;
2996 	struct ext4_li_request *elr;
2997 	unsigned long next_wakeup, cur;
2998 
2999 	BUG_ON(NULL == eli);
3000 
3001 cont_thread:
3002 	while (true) {
3003 		next_wakeup = MAX_JIFFY_OFFSET;
3004 
3005 		mutex_lock(&eli->li_list_mtx);
3006 		if (list_empty(&eli->li_request_list)) {
3007 			mutex_unlock(&eli->li_list_mtx);
3008 			goto exit_thread;
3009 		}
3010 		list_for_each_safe(pos, n, &eli->li_request_list) {
3011 			int err = 0;
3012 			int progress = 0;
3013 			elr = list_entry(pos, struct ext4_li_request,
3014 					 lr_request);
3015 
3016 			if (time_before(jiffies, elr->lr_next_sched)) {
3017 				if (time_before(elr->lr_next_sched, next_wakeup))
3018 					next_wakeup = elr->lr_next_sched;
3019 				continue;
3020 			}
3021 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3022 				if (sb_start_write_trylock(elr->lr_super)) {
3023 					progress = 1;
3024 					/*
3025 					 * We hold sb->s_umount, sb can not
3026 					 * be removed from the list, it is
3027 					 * now safe to drop li_list_mtx
3028 					 */
3029 					mutex_unlock(&eli->li_list_mtx);
3030 					err = ext4_run_li_request(elr);
3031 					sb_end_write(elr->lr_super);
3032 					mutex_lock(&eli->li_list_mtx);
3033 					n = pos->next;
3034 				}
3035 				up_read((&elr->lr_super->s_umount));
3036 			}
3037 			/* error, remove the lazy_init job */
3038 			if (err) {
3039 				ext4_remove_li_request(elr);
3040 				continue;
3041 			}
3042 			if (!progress) {
3043 				elr->lr_next_sched = jiffies +
3044 					(prandom_u32()
3045 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3046 			}
3047 			if (time_before(elr->lr_next_sched, next_wakeup))
3048 				next_wakeup = elr->lr_next_sched;
3049 		}
3050 		mutex_unlock(&eli->li_list_mtx);
3051 
3052 		try_to_freeze();
3053 
3054 		cur = jiffies;
3055 		if ((time_after_eq(cur, next_wakeup)) ||
3056 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3057 			cond_resched();
3058 			continue;
3059 		}
3060 
3061 		schedule_timeout_interruptible(next_wakeup - cur);
3062 
3063 		if (kthread_should_stop()) {
3064 			ext4_clear_request_list();
3065 			goto exit_thread;
3066 		}
3067 	}
3068 
3069 exit_thread:
3070 	/*
3071 	 * It looks like the request list is empty, but we need
3072 	 * to check it under the li_list_mtx lock, to prevent any
3073 	 * additions into it, and of course we should lock ext4_li_mtx
3074 	 * to atomically free the list and ext4_li_info, because at
3075 	 * this point another ext4 filesystem could be registering
3076 	 * new one.
3077 	 */
3078 	mutex_lock(&ext4_li_mtx);
3079 	mutex_lock(&eli->li_list_mtx);
3080 	if (!list_empty(&eli->li_request_list)) {
3081 		mutex_unlock(&eli->li_list_mtx);
3082 		mutex_unlock(&ext4_li_mtx);
3083 		goto cont_thread;
3084 	}
3085 	mutex_unlock(&eli->li_list_mtx);
3086 	kfree(ext4_li_info);
3087 	ext4_li_info = NULL;
3088 	mutex_unlock(&ext4_li_mtx);
3089 
3090 	return 0;
3091 }
3092 
3093 static void ext4_clear_request_list(void)
3094 {
3095 	struct list_head *pos, *n;
3096 	struct ext4_li_request *elr;
3097 
3098 	mutex_lock(&ext4_li_info->li_list_mtx);
3099 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3100 		elr = list_entry(pos, struct ext4_li_request,
3101 				 lr_request);
3102 		ext4_remove_li_request(elr);
3103 	}
3104 	mutex_unlock(&ext4_li_info->li_list_mtx);
3105 }
3106 
3107 static int ext4_run_lazyinit_thread(void)
3108 {
3109 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3110 					 ext4_li_info, "ext4lazyinit");
3111 	if (IS_ERR(ext4_lazyinit_task)) {
3112 		int err = PTR_ERR(ext4_lazyinit_task);
3113 		ext4_clear_request_list();
3114 		kfree(ext4_li_info);
3115 		ext4_li_info = NULL;
3116 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3117 				 "initialization thread\n",
3118 				 err);
3119 		return err;
3120 	}
3121 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3122 	return 0;
3123 }
3124 
3125 /*
3126  * Check whether it make sense to run itable init. thread or not.
3127  * If there is at least one uninitialized inode table, return
3128  * corresponding group number, else the loop goes through all
3129  * groups and return total number of groups.
3130  */
3131 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3132 {
3133 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3134 	struct ext4_group_desc *gdp = NULL;
3135 
3136 	if (!ext4_has_group_desc_csum(sb))
3137 		return ngroups;
3138 
3139 	for (group = 0; group < ngroups; group++) {
3140 		gdp = ext4_get_group_desc(sb, group, NULL);
3141 		if (!gdp)
3142 			continue;
3143 
3144 		if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
3145 			continue;
3146 		if (group != 0)
3147 			break;
3148 		ext4_error(sb, "Inode table for bg 0 marked as "
3149 			   "needing zeroing");
3150 		if (sb_rdonly(sb))
3151 			return ngroups;
3152 	}
3153 
3154 	return group;
3155 }
3156 
3157 static int ext4_li_info_new(void)
3158 {
3159 	struct ext4_lazy_init *eli = NULL;
3160 
3161 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3162 	if (!eli)
3163 		return -ENOMEM;
3164 
3165 	INIT_LIST_HEAD(&eli->li_request_list);
3166 	mutex_init(&eli->li_list_mtx);
3167 
3168 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3169 
3170 	ext4_li_info = eli;
3171 
3172 	return 0;
3173 }
3174 
3175 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3176 					    ext4_group_t start)
3177 {
3178 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3179 	struct ext4_li_request *elr;
3180 
3181 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3182 	if (!elr)
3183 		return NULL;
3184 
3185 	elr->lr_super = sb;
3186 	elr->lr_sbi = sbi;
3187 	elr->lr_next_group = start;
3188 
3189 	/*
3190 	 * Randomize first schedule time of the request to
3191 	 * spread the inode table initialization requests
3192 	 * better.
3193 	 */
3194 	elr->lr_next_sched = jiffies + (prandom_u32() %
3195 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3196 	return elr;
3197 }
3198 
3199 int ext4_register_li_request(struct super_block *sb,
3200 			     ext4_group_t first_not_zeroed)
3201 {
3202 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3203 	struct ext4_li_request *elr = NULL;
3204 	ext4_group_t ngroups = sbi->s_groups_count;
3205 	int ret = 0;
3206 
3207 	mutex_lock(&ext4_li_mtx);
3208 	if (sbi->s_li_request != NULL) {
3209 		/*
3210 		 * Reset timeout so it can be computed again, because
3211 		 * s_li_wait_mult might have changed.
3212 		 */
3213 		sbi->s_li_request->lr_timeout = 0;
3214 		goto out;
3215 	}
3216 
3217 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3218 	    !test_opt(sb, INIT_INODE_TABLE))
3219 		goto out;
3220 
3221 	elr = ext4_li_request_new(sb, first_not_zeroed);
3222 	if (!elr) {
3223 		ret = -ENOMEM;
3224 		goto out;
3225 	}
3226 
3227 	if (NULL == ext4_li_info) {
3228 		ret = ext4_li_info_new();
3229 		if (ret)
3230 			goto out;
3231 	}
3232 
3233 	mutex_lock(&ext4_li_info->li_list_mtx);
3234 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3235 	mutex_unlock(&ext4_li_info->li_list_mtx);
3236 
3237 	sbi->s_li_request = elr;
3238 	/*
3239 	 * set elr to NULL here since it has been inserted to
3240 	 * the request_list and the removal and free of it is
3241 	 * handled by ext4_clear_request_list from now on.
3242 	 */
3243 	elr = NULL;
3244 
3245 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3246 		ret = ext4_run_lazyinit_thread();
3247 		if (ret)
3248 			goto out;
3249 	}
3250 out:
3251 	mutex_unlock(&ext4_li_mtx);
3252 	if (ret)
3253 		kfree(elr);
3254 	return ret;
3255 }
3256 
3257 /*
3258  * We do not need to lock anything since this is called on
3259  * module unload.
3260  */
3261 static void ext4_destroy_lazyinit_thread(void)
3262 {
3263 	/*
3264 	 * If thread exited earlier
3265 	 * there's nothing to be done.
3266 	 */
3267 	if (!ext4_li_info || !ext4_lazyinit_task)
3268 		return;
3269 
3270 	kthread_stop(ext4_lazyinit_task);
3271 }
3272 
3273 static int set_journal_csum_feature_set(struct super_block *sb)
3274 {
3275 	int ret = 1;
3276 	int compat, incompat;
3277 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3278 
3279 	if (ext4_has_metadata_csum(sb)) {
3280 		/* journal checksum v3 */
3281 		compat = 0;
3282 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3283 	} else {
3284 		/* journal checksum v1 */
3285 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3286 		incompat = 0;
3287 	}
3288 
3289 	jbd2_journal_clear_features(sbi->s_journal,
3290 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3291 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3292 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3293 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3294 		ret = jbd2_journal_set_features(sbi->s_journal,
3295 				compat, 0,
3296 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3297 				incompat);
3298 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3299 		ret = jbd2_journal_set_features(sbi->s_journal,
3300 				compat, 0,
3301 				incompat);
3302 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3303 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3304 	} else {
3305 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3306 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3307 	}
3308 
3309 	return ret;
3310 }
3311 
3312 /*
3313  * Note: calculating the overhead so we can be compatible with
3314  * historical BSD practice is quite difficult in the face of
3315  * clusters/bigalloc.  This is because multiple metadata blocks from
3316  * different block group can end up in the same allocation cluster.
3317  * Calculating the exact overhead in the face of clustered allocation
3318  * requires either O(all block bitmaps) in memory or O(number of block
3319  * groups**2) in time.  We will still calculate the superblock for
3320  * older file systems --- and if we come across with a bigalloc file
3321  * system with zero in s_overhead_clusters the estimate will be close to
3322  * correct especially for very large cluster sizes --- but for newer
3323  * file systems, it's better to calculate this figure once at mkfs
3324  * time, and store it in the superblock.  If the superblock value is
3325  * present (even for non-bigalloc file systems), we will use it.
3326  */
3327 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3328 			  char *buf)
3329 {
3330 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3331 	struct ext4_group_desc	*gdp;
3332 	ext4_fsblk_t		first_block, last_block, b;
3333 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3334 	int			s, j, count = 0;
3335 
3336 	if (!ext4_has_feature_bigalloc(sb))
3337 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3338 			sbi->s_itb_per_group + 2);
3339 
3340 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3341 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3342 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3343 	for (i = 0; i < ngroups; i++) {
3344 		gdp = ext4_get_group_desc(sb, i, NULL);
3345 		b = ext4_block_bitmap(sb, gdp);
3346 		if (b >= first_block && b <= last_block) {
3347 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3348 			count++;
3349 		}
3350 		b = ext4_inode_bitmap(sb, gdp);
3351 		if (b >= first_block && b <= last_block) {
3352 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3353 			count++;
3354 		}
3355 		b = ext4_inode_table(sb, gdp);
3356 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3357 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3358 				int c = EXT4_B2C(sbi, b - first_block);
3359 				ext4_set_bit(c, buf);
3360 				count++;
3361 			}
3362 		if (i != grp)
3363 			continue;
3364 		s = 0;
3365 		if (ext4_bg_has_super(sb, grp)) {
3366 			ext4_set_bit(s++, buf);
3367 			count++;
3368 		}
3369 		j = ext4_bg_num_gdb(sb, grp);
3370 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3371 			ext4_error(sb, "Invalid number of block group "
3372 				   "descriptor blocks: %d", j);
3373 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3374 		}
3375 		count += j;
3376 		for (; j > 0; j--)
3377 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3378 	}
3379 	if (!count)
3380 		return 0;
3381 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3382 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3383 }
3384 
3385 /*
3386  * Compute the overhead and stash it in sbi->s_overhead
3387  */
3388 int ext4_calculate_overhead(struct super_block *sb)
3389 {
3390 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3391 	struct ext4_super_block *es = sbi->s_es;
3392 	struct inode *j_inode;
3393 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3394 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3395 	ext4_fsblk_t overhead = 0;
3396 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3397 
3398 	if (!buf)
3399 		return -ENOMEM;
3400 
3401 	/*
3402 	 * Compute the overhead (FS structures).  This is constant
3403 	 * for a given filesystem unless the number of block groups
3404 	 * changes so we cache the previous value until it does.
3405 	 */
3406 
3407 	/*
3408 	 * All of the blocks before first_data_block are overhead
3409 	 */
3410 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3411 
3412 	/*
3413 	 * Add the overhead found in each block group
3414 	 */
3415 	for (i = 0; i < ngroups; i++) {
3416 		int blks;
3417 
3418 		blks = count_overhead(sb, i, buf);
3419 		overhead += blks;
3420 		if (blks)
3421 			memset(buf, 0, PAGE_SIZE);
3422 		cond_resched();
3423 	}
3424 
3425 	/*
3426 	 * Add the internal journal blocks whether the journal has been
3427 	 * loaded or not
3428 	 */
3429 	if (sbi->s_journal && !sbi->journal_bdev)
3430 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3431 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3432 		j_inode = ext4_get_journal_inode(sb, j_inum);
3433 		if (j_inode) {
3434 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3435 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3436 			iput(j_inode);
3437 		} else {
3438 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3439 		}
3440 	}
3441 	sbi->s_overhead = overhead;
3442 	smp_wmb();
3443 	free_page((unsigned long) buf);
3444 	return 0;
3445 }
3446 
3447 static void ext4_set_resv_clusters(struct super_block *sb)
3448 {
3449 	ext4_fsblk_t resv_clusters;
3450 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3451 
3452 	/*
3453 	 * There's no need to reserve anything when we aren't using extents.
3454 	 * The space estimates are exact, there are no unwritten extents,
3455 	 * hole punching doesn't need new metadata... This is needed especially
3456 	 * to keep ext2/3 backward compatibility.
3457 	 */
3458 	if (!ext4_has_feature_extents(sb))
3459 		return;
3460 	/*
3461 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3462 	 * This should cover the situations where we can not afford to run
3463 	 * out of space like for example punch hole, or converting
3464 	 * unwritten extents in delalloc path. In most cases such
3465 	 * allocation would require 1, or 2 blocks, higher numbers are
3466 	 * very rare.
3467 	 */
3468 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3469 			 sbi->s_cluster_bits);
3470 
3471 	do_div(resv_clusters, 50);
3472 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3473 
3474 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3475 }
3476 
3477 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3478 {
3479 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3480 	char *orig_data = kstrdup(data, GFP_KERNEL);
3481 	struct buffer_head *bh;
3482 	struct ext4_super_block *es = NULL;
3483 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3484 	ext4_fsblk_t block;
3485 	ext4_fsblk_t sb_block = get_sb_block(&data);
3486 	ext4_fsblk_t logical_sb_block;
3487 	unsigned long offset = 0;
3488 	unsigned long journal_devnum = 0;
3489 	unsigned long def_mount_opts;
3490 	struct inode *root;
3491 	const char *descr;
3492 	int ret = -ENOMEM;
3493 	int blocksize, clustersize;
3494 	unsigned int db_count;
3495 	unsigned int i;
3496 	int needs_recovery, has_huge_files, has_bigalloc;
3497 	__u64 blocks_count;
3498 	int err = 0;
3499 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3500 	ext4_group_t first_not_zeroed;
3501 
3502 	if ((data && !orig_data) || !sbi)
3503 		goto out_free_base;
3504 
3505 	sbi->s_daxdev = dax_dev;
3506 	sbi->s_blockgroup_lock =
3507 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3508 	if (!sbi->s_blockgroup_lock)
3509 		goto out_free_base;
3510 
3511 	sb->s_fs_info = sbi;
3512 	sbi->s_sb = sb;
3513 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3514 	sbi->s_sb_block = sb_block;
3515 	if (sb->s_bdev->bd_part)
3516 		sbi->s_sectors_written_start =
3517 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3518 
3519 	/* Cleanup superblock name */
3520 	strreplace(sb->s_id, '/', '!');
3521 
3522 	/* -EINVAL is default */
3523 	ret = -EINVAL;
3524 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3525 	if (!blocksize) {
3526 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3527 		goto out_fail;
3528 	}
3529 
3530 	/*
3531 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3532 	 * block sizes.  We need to calculate the offset from buffer start.
3533 	 */
3534 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3535 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3536 		offset = do_div(logical_sb_block, blocksize);
3537 	} else {
3538 		logical_sb_block = sb_block;
3539 	}
3540 
3541 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3542 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3543 		goto out_fail;
3544 	}
3545 	/*
3546 	 * Note: s_es must be initialized as soon as possible because
3547 	 *       some ext4 macro-instructions depend on its value
3548 	 */
3549 	es = (struct ext4_super_block *) (bh->b_data + offset);
3550 	sbi->s_es = es;
3551 	sb->s_magic = le16_to_cpu(es->s_magic);
3552 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3553 		goto cantfind_ext4;
3554 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3555 
3556 	/* Warn if metadata_csum and gdt_csum are both set. */
3557 	if (ext4_has_feature_metadata_csum(sb) &&
3558 	    ext4_has_feature_gdt_csum(sb))
3559 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3560 			     "redundant flags; please run fsck.");
3561 
3562 	/* Check for a known checksum algorithm */
3563 	if (!ext4_verify_csum_type(sb, es)) {
3564 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3565 			 "unknown checksum algorithm.");
3566 		silent = 1;
3567 		goto cantfind_ext4;
3568 	}
3569 
3570 	/* Load the checksum driver */
3571 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3572 	if (IS_ERR(sbi->s_chksum_driver)) {
3573 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3574 		ret = PTR_ERR(sbi->s_chksum_driver);
3575 		sbi->s_chksum_driver = NULL;
3576 		goto failed_mount;
3577 	}
3578 
3579 	/* Check superblock checksum */
3580 	if (!ext4_superblock_csum_verify(sb, es)) {
3581 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3582 			 "invalid superblock checksum.  Run e2fsck?");
3583 		silent = 1;
3584 		ret = -EFSBADCRC;
3585 		goto cantfind_ext4;
3586 	}
3587 
3588 	/* Precompute checksum seed for all metadata */
3589 	if (ext4_has_feature_csum_seed(sb))
3590 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3591 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3592 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3593 					       sizeof(es->s_uuid));
3594 
3595 	/* Set defaults before we parse the mount options */
3596 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3597 	set_opt(sb, INIT_INODE_TABLE);
3598 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3599 		set_opt(sb, DEBUG);
3600 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3601 		set_opt(sb, GRPID);
3602 	if (def_mount_opts & EXT4_DEFM_UID16)
3603 		set_opt(sb, NO_UID32);
3604 	/* xattr user namespace & acls are now defaulted on */
3605 	set_opt(sb, XATTR_USER);
3606 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3607 	set_opt(sb, POSIX_ACL);
3608 #endif
3609 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3610 	if (ext4_has_metadata_csum(sb))
3611 		set_opt(sb, JOURNAL_CHECKSUM);
3612 
3613 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3614 		set_opt(sb, JOURNAL_DATA);
3615 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3616 		set_opt(sb, ORDERED_DATA);
3617 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3618 		set_opt(sb, WRITEBACK_DATA);
3619 
3620 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3621 		set_opt(sb, ERRORS_PANIC);
3622 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3623 		set_opt(sb, ERRORS_CONT);
3624 	else
3625 		set_opt(sb, ERRORS_RO);
3626 	/* block_validity enabled by default; disable with noblock_validity */
3627 	set_opt(sb, BLOCK_VALIDITY);
3628 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3629 		set_opt(sb, DISCARD);
3630 
3631 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3632 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3633 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3634 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3635 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3636 
3637 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3638 		set_opt(sb, BARRIER);
3639 
3640 	/*
3641 	 * enable delayed allocation by default
3642 	 * Use -o nodelalloc to turn it off
3643 	 */
3644 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3645 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3646 		set_opt(sb, DELALLOC);
3647 
3648 	/*
3649 	 * set default s_li_wait_mult for lazyinit, for the case there is
3650 	 * no mount option specified.
3651 	 */
3652 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3653 
3654 	if (sbi->s_es->s_mount_opts[0]) {
3655 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3656 					      sizeof(sbi->s_es->s_mount_opts),
3657 					      GFP_KERNEL);
3658 		if (!s_mount_opts)
3659 			goto failed_mount;
3660 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3661 				   &journal_ioprio, 0)) {
3662 			ext4_msg(sb, KERN_WARNING,
3663 				 "failed to parse options in superblock: %s",
3664 				 s_mount_opts);
3665 		}
3666 		kfree(s_mount_opts);
3667 	}
3668 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3669 	if (!parse_options((char *) data, sb, &journal_devnum,
3670 			   &journal_ioprio, 0))
3671 		goto failed_mount;
3672 
3673 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3674 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3675 			    "with data=journal disables delayed "
3676 			    "allocation and O_DIRECT support!\n");
3677 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3678 			ext4_msg(sb, KERN_ERR, "can't mount with "
3679 				 "both data=journal and delalloc");
3680 			goto failed_mount;
3681 		}
3682 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3683 			ext4_msg(sb, KERN_ERR, "can't mount with "
3684 				 "both data=journal and dioread_nolock");
3685 			goto failed_mount;
3686 		}
3687 		if (test_opt(sb, DAX)) {
3688 			ext4_msg(sb, KERN_ERR, "can't mount with "
3689 				 "both data=journal and dax");
3690 			goto failed_mount;
3691 		}
3692 		if (ext4_has_feature_encrypt(sb)) {
3693 			ext4_msg(sb, KERN_WARNING,
3694 				 "encrypted files will use data=ordered "
3695 				 "instead of data journaling mode");
3696 		}
3697 		if (test_opt(sb, DELALLOC))
3698 			clear_opt(sb, DELALLOC);
3699 	} else {
3700 		sb->s_iflags |= SB_I_CGROUPWB;
3701 	}
3702 
3703 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3704 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3705 
3706 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3707 	    (ext4_has_compat_features(sb) ||
3708 	     ext4_has_ro_compat_features(sb) ||
3709 	     ext4_has_incompat_features(sb)))
3710 		ext4_msg(sb, KERN_WARNING,
3711 		       "feature flags set on rev 0 fs, "
3712 		       "running e2fsck is recommended");
3713 
3714 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3715 		set_opt2(sb, HURD_COMPAT);
3716 		if (ext4_has_feature_64bit(sb)) {
3717 			ext4_msg(sb, KERN_ERR,
3718 				 "The Hurd can't support 64-bit file systems");
3719 			goto failed_mount;
3720 		}
3721 
3722 		/*
3723 		 * ea_inode feature uses l_i_version field which is not
3724 		 * available in HURD_COMPAT mode.
3725 		 */
3726 		if (ext4_has_feature_ea_inode(sb)) {
3727 			ext4_msg(sb, KERN_ERR,
3728 				 "ea_inode feature is not supported for Hurd");
3729 			goto failed_mount;
3730 		}
3731 	}
3732 
3733 	if (IS_EXT2_SB(sb)) {
3734 		if (ext2_feature_set_ok(sb))
3735 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3736 				 "using the ext4 subsystem");
3737 		else {
3738 			/*
3739 			 * If we're probing be silent, if this looks like
3740 			 * it's actually an ext[34] filesystem.
3741 			 */
3742 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3743 				goto failed_mount;
3744 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3745 				 "to feature incompatibilities");
3746 			goto failed_mount;
3747 		}
3748 	}
3749 
3750 	if (IS_EXT3_SB(sb)) {
3751 		if (ext3_feature_set_ok(sb))
3752 			ext4_msg(sb, KERN_INFO, "mounting ext3 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 ext4 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 ext3 due "
3762 				 "to feature incompatibilities");
3763 			goto failed_mount;
3764 		}
3765 	}
3766 
3767 	/*
3768 	 * Check feature flags regardless of the revision level, since we
3769 	 * previously didn't change the revision level when setting the flags,
3770 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3771 	 */
3772 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3773 		goto failed_mount;
3774 
3775 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3776 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3777 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3778 		ext4_msg(sb, KERN_ERR,
3779 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3780 			 blocksize, le32_to_cpu(es->s_log_block_size));
3781 		goto failed_mount;
3782 	}
3783 	if (le32_to_cpu(es->s_log_block_size) >
3784 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3785 		ext4_msg(sb, KERN_ERR,
3786 			 "Invalid log block size: %u",
3787 			 le32_to_cpu(es->s_log_block_size));
3788 		goto failed_mount;
3789 	}
3790 	if (le32_to_cpu(es->s_log_cluster_size) >
3791 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3792 		ext4_msg(sb, KERN_ERR,
3793 			 "Invalid log cluster size: %u",
3794 			 le32_to_cpu(es->s_log_cluster_size));
3795 		goto failed_mount;
3796 	}
3797 
3798 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3799 		ext4_msg(sb, KERN_ERR,
3800 			 "Number of reserved GDT blocks insanely large: %d",
3801 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3802 		goto failed_mount;
3803 	}
3804 
3805 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3806 		if (ext4_has_feature_inline_data(sb)) {
3807 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3808 					" that may contain inline data");
3809 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
3810 		}
3811 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
3812 			ext4_msg(sb, KERN_ERR,
3813 				"DAX unsupported by block device. Turning off DAX.");
3814 			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
3815 		}
3816 	}
3817 
3818 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3819 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3820 			 es->s_encryption_level);
3821 		goto failed_mount;
3822 	}
3823 
3824 	if (sb->s_blocksize != blocksize) {
3825 		/* Validate the filesystem blocksize */
3826 		if (!sb_set_blocksize(sb, blocksize)) {
3827 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3828 					blocksize);
3829 			goto failed_mount;
3830 		}
3831 
3832 		brelse(bh);
3833 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3834 		offset = do_div(logical_sb_block, blocksize);
3835 		bh = sb_bread_unmovable(sb, logical_sb_block);
3836 		if (!bh) {
3837 			ext4_msg(sb, KERN_ERR,
3838 			       "Can't read superblock on 2nd try");
3839 			goto failed_mount;
3840 		}
3841 		es = (struct ext4_super_block *)(bh->b_data + offset);
3842 		sbi->s_es = es;
3843 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3844 			ext4_msg(sb, KERN_ERR,
3845 			       "Magic mismatch, very weird!");
3846 			goto failed_mount;
3847 		}
3848 	}
3849 
3850 	has_huge_files = ext4_has_feature_huge_file(sb);
3851 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3852 						      has_huge_files);
3853 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3854 
3855 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3856 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3857 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3858 	} else {
3859 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3860 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3861 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3862 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3863 				 sbi->s_first_ino);
3864 			goto failed_mount;
3865 		}
3866 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3867 		    (!is_power_of_2(sbi->s_inode_size)) ||
3868 		    (sbi->s_inode_size > blocksize)) {
3869 			ext4_msg(sb, KERN_ERR,
3870 			       "unsupported inode size: %d",
3871 			       sbi->s_inode_size);
3872 			goto failed_mount;
3873 		}
3874 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3875 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3876 	}
3877 
3878 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3879 	if (ext4_has_feature_64bit(sb)) {
3880 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3881 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3882 		    !is_power_of_2(sbi->s_desc_size)) {
3883 			ext4_msg(sb, KERN_ERR,
3884 			       "unsupported descriptor size %lu",
3885 			       sbi->s_desc_size);
3886 			goto failed_mount;
3887 		}
3888 	} else
3889 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3890 
3891 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3892 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3893 
3894 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3895 	if (sbi->s_inodes_per_block == 0)
3896 		goto cantfind_ext4;
3897 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3898 	    sbi->s_inodes_per_group > blocksize * 8) {
3899 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3900 			 sbi->s_blocks_per_group);
3901 		goto failed_mount;
3902 	}
3903 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3904 					sbi->s_inodes_per_block;
3905 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3906 	sbi->s_sbh = bh;
3907 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3908 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3909 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3910 
3911 	for (i = 0; i < 4; i++)
3912 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3913 	sbi->s_def_hash_version = es->s_def_hash_version;
3914 	if (ext4_has_feature_dir_index(sb)) {
3915 		i = le32_to_cpu(es->s_flags);
3916 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3917 			sbi->s_hash_unsigned = 3;
3918 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3919 #ifdef __CHAR_UNSIGNED__
3920 			if (!sb_rdonly(sb))
3921 				es->s_flags |=
3922 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3923 			sbi->s_hash_unsigned = 3;
3924 #else
3925 			if (!sb_rdonly(sb))
3926 				es->s_flags |=
3927 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3928 #endif
3929 		}
3930 	}
3931 
3932 	/* Handle clustersize */
3933 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3934 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3935 	if (has_bigalloc) {
3936 		if (clustersize < blocksize) {
3937 			ext4_msg(sb, KERN_ERR,
3938 				 "cluster size (%d) smaller than "
3939 				 "block size (%d)", clustersize, blocksize);
3940 			goto failed_mount;
3941 		}
3942 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3943 			le32_to_cpu(es->s_log_block_size);
3944 		sbi->s_clusters_per_group =
3945 			le32_to_cpu(es->s_clusters_per_group);
3946 		if (sbi->s_clusters_per_group > blocksize * 8) {
3947 			ext4_msg(sb, KERN_ERR,
3948 				 "#clusters per group too big: %lu",
3949 				 sbi->s_clusters_per_group);
3950 			goto failed_mount;
3951 		}
3952 		if (sbi->s_blocks_per_group !=
3953 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3954 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3955 				 "clusters per group (%lu) inconsistent",
3956 				 sbi->s_blocks_per_group,
3957 				 sbi->s_clusters_per_group);
3958 			goto failed_mount;
3959 		}
3960 	} else {
3961 		if (clustersize != blocksize) {
3962 			ext4_msg(sb, KERN_ERR,
3963 				 "fragment/cluster size (%d) != "
3964 				 "block size (%d)", clustersize, blocksize);
3965 			goto failed_mount;
3966 		}
3967 		if (sbi->s_blocks_per_group > blocksize * 8) {
3968 			ext4_msg(sb, KERN_ERR,
3969 				 "#blocks per group too big: %lu",
3970 				 sbi->s_blocks_per_group);
3971 			goto failed_mount;
3972 		}
3973 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3974 		sbi->s_cluster_bits = 0;
3975 	}
3976 	sbi->s_cluster_ratio = clustersize / blocksize;
3977 
3978 	/* Do we have standard group size of clustersize * 8 blocks ? */
3979 	if (sbi->s_blocks_per_group == clustersize << 3)
3980 		set_opt2(sb, STD_GROUP_SIZE);
3981 
3982 	/*
3983 	 * Test whether we have more sectors than will fit in sector_t,
3984 	 * and whether the max offset is addressable by the page cache.
3985 	 */
3986 	err = generic_check_addressable(sb->s_blocksize_bits,
3987 					ext4_blocks_count(es));
3988 	if (err) {
3989 		ext4_msg(sb, KERN_ERR, "filesystem"
3990 			 " too large to mount safely on this system");
3991 		if (sizeof(sector_t) < 8)
3992 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3993 		goto failed_mount;
3994 	}
3995 
3996 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3997 		goto cantfind_ext4;
3998 
3999 	/* check blocks count against device size */
4000 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4001 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4002 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4003 		       "exceeds size of device (%llu blocks)",
4004 		       ext4_blocks_count(es), blocks_count);
4005 		goto failed_mount;
4006 	}
4007 
4008 	/*
4009 	 * It makes no sense for the first data block to be beyond the end
4010 	 * of the filesystem.
4011 	 */
4012 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4013 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4014 			 "block %u is beyond end of filesystem (%llu)",
4015 			 le32_to_cpu(es->s_first_data_block),
4016 			 ext4_blocks_count(es));
4017 		goto failed_mount;
4018 	}
4019 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4020 	    (sbi->s_cluster_ratio == 1)) {
4021 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4022 			 "block is 0 with a 1k block and cluster size");
4023 		goto failed_mount;
4024 	}
4025 
4026 	blocks_count = (ext4_blocks_count(es) -
4027 			le32_to_cpu(es->s_first_data_block) +
4028 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4029 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4030 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4031 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4032 		       "(block count %llu, first data block %u, "
4033 		       "blocks per group %lu)", sbi->s_groups_count,
4034 		       ext4_blocks_count(es),
4035 		       le32_to_cpu(es->s_first_data_block),
4036 		       EXT4_BLOCKS_PER_GROUP(sb));
4037 		goto failed_mount;
4038 	}
4039 	sbi->s_groups_count = blocks_count;
4040 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4041 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4042 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4043 		   EXT4_DESC_PER_BLOCK(sb);
4044 	if (ext4_has_feature_meta_bg(sb)) {
4045 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4046 			ext4_msg(sb, KERN_WARNING,
4047 				 "first meta block group too large: %u "
4048 				 "(group descriptor block count %u)",
4049 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4050 			goto failed_mount;
4051 		}
4052 	}
4053 	sbi->s_group_desc = kvmalloc_array(db_count,
4054 					   sizeof(struct buffer_head *),
4055 					   GFP_KERNEL);
4056 	if (sbi->s_group_desc == NULL) {
4057 		ext4_msg(sb, KERN_ERR, "not enough memory");
4058 		ret = -ENOMEM;
4059 		goto failed_mount;
4060 	}
4061 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4062 	    le32_to_cpu(es->s_inodes_count)) {
4063 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4064 			 le32_to_cpu(es->s_inodes_count),
4065 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4066 		ret = -EINVAL;
4067 		goto failed_mount;
4068 	}
4069 
4070 	bgl_lock_init(sbi->s_blockgroup_lock);
4071 
4072 	/* Pre-read the descriptors into the buffer cache */
4073 	for (i = 0; i < db_count; i++) {
4074 		block = descriptor_loc(sb, logical_sb_block, i);
4075 		sb_breadahead(sb, block);
4076 	}
4077 
4078 	for (i = 0; i < db_count; i++) {
4079 		block = descriptor_loc(sb, logical_sb_block, i);
4080 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4081 		if (!sbi->s_group_desc[i]) {
4082 			ext4_msg(sb, KERN_ERR,
4083 			       "can't read group descriptor %d", i);
4084 			db_count = i;
4085 			goto failed_mount2;
4086 		}
4087 	}
4088 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4089 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4090 		ret = -EFSCORRUPTED;
4091 		goto failed_mount2;
4092 	}
4093 
4094 	sbi->s_gdb_count = db_count;
4095 
4096 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4097 
4098 	/* Register extent status tree shrinker */
4099 	if (ext4_es_register_shrinker(sbi))
4100 		goto failed_mount3;
4101 
4102 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4103 	sbi->s_extent_max_zeroout_kb = 32;
4104 
4105 	/*
4106 	 * set up enough so that it can read an inode
4107 	 */
4108 	sb->s_op = &ext4_sops;
4109 	sb->s_export_op = &ext4_export_ops;
4110 	sb->s_xattr = ext4_xattr_handlers;
4111 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4112 	sb->s_cop = &ext4_cryptops;
4113 #endif
4114 #ifdef CONFIG_QUOTA
4115 	sb->dq_op = &ext4_quota_operations;
4116 	if (ext4_has_feature_quota(sb))
4117 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4118 	else
4119 		sb->s_qcop = &ext4_qctl_operations;
4120 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4121 #endif
4122 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4123 
4124 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4125 	mutex_init(&sbi->s_orphan_lock);
4126 
4127 	sb->s_root = NULL;
4128 
4129 	needs_recovery = (es->s_last_orphan != 0 ||
4130 			  ext4_has_feature_journal_needs_recovery(sb));
4131 
4132 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4133 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4134 			goto failed_mount3a;
4135 
4136 	/*
4137 	 * The first inode we look at is the journal inode.  Don't try
4138 	 * root first: it may be modified in the journal!
4139 	 */
4140 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4141 		err = ext4_load_journal(sb, es, journal_devnum);
4142 		if (err)
4143 			goto failed_mount3a;
4144 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4145 		   ext4_has_feature_journal_needs_recovery(sb)) {
4146 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4147 		       "suppressed and not mounted read-only");
4148 		goto failed_mount_wq;
4149 	} else {
4150 		/* Nojournal mode, all journal mount options are illegal */
4151 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4152 			ext4_msg(sb, KERN_ERR, "can't mount with "
4153 				 "journal_checksum, fs mounted w/o journal");
4154 			goto failed_mount_wq;
4155 		}
4156 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4157 			ext4_msg(sb, KERN_ERR, "can't mount with "
4158 				 "journal_async_commit, fs mounted w/o journal");
4159 			goto failed_mount_wq;
4160 		}
4161 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4162 			ext4_msg(sb, KERN_ERR, "can't mount with "
4163 				 "commit=%lu, fs mounted w/o journal",
4164 				 sbi->s_commit_interval / HZ);
4165 			goto failed_mount_wq;
4166 		}
4167 		if (EXT4_MOUNT_DATA_FLAGS &
4168 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4169 			ext4_msg(sb, KERN_ERR, "can't mount with "
4170 				 "data=, fs mounted w/o journal");
4171 			goto failed_mount_wq;
4172 		}
4173 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4174 		clear_opt(sb, JOURNAL_CHECKSUM);
4175 		clear_opt(sb, DATA_FLAGS);
4176 		sbi->s_journal = NULL;
4177 		needs_recovery = 0;
4178 		goto no_journal;
4179 	}
4180 
4181 	if (ext4_has_feature_64bit(sb) &&
4182 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4183 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4184 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4185 		goto failed_mount_wq;
4186 	}
4187 
4188 	if (!set_journal_csum_feature_set(sb)) {
4189 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4190 			 "feature set");
4191 		goto failed_mount_wq;
4192 	}
4193 
4194 	/* We have now updated the journal if required, so we can
4195 	 * validate the data journaling mode. */
4196 	switch (test_opt(sb, DATA_FLAGS)) {
4197 	case 0:
4198 		/* No mode set, assume a default based on the journal
4199 		 * capabilities: ORDERED_DATA if the journal can
4200 		 * cope, else JOURNAL_DATA
4201 		 */
4202 		if (jbd2_journal_check_available_features
4203 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4204 			set_opt(sb, ORDERED_DATA);
4205 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4206 		} else {
4207 			set_opt(sb, JOURNAL_DATA);
4208 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4209 		}
4210 		break;
4211 
4212 	case EXT4_MOUNT_ORDERED_DATA:
4213 	case EXT4_MOUNT_WRITEBACK_DATA:
4214 		if (!jbd2_journal_check_available_features
4215 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4216 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4217 			       "requested data journaling mode");
4218 			goto failed_mount_wq;
4219 		}
4220 	default:
4221 		break;
4222 	}
4223 
4224 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4225 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4226 		ext4_msg(sb, KERN_ERR, "can't mount with "
4227 			"journal_async_commit in data=ordered mode");
4228 		goto failed_mount_wq;
4229 	}
4230 
4231 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4232 
4233 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4234 
4235 no_journal:
4236 	if (!test_opt(sb, NO_MBCACHE)) {
4237 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4238 		if (!sbi->s_ea_block_cache) {
4239 			ext4_msg(sb, KERN_ERR,
4240 				 "Failed to create ea_block_cache");
4241 			goto failed_mount_wq;
4242 		}
4243 
4244 		if (ext4_has_feature_ea_inode(sb)) {
4245 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4246 			if (!sbi->s_ea_inode_cache) {
4247 				ext4_msg(sb, KERN_ERR,
4248 					 "Failed to create ea_inode_cache");
4249 				goto failed_mount_wq;
4250 			}
4251 		}
4252 	}
4253 
4254 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4255 	    (blocksize != PAGE_SIZE)) {
4256 		ext4_msg(sb, KERN_ERR,
4257 			 "Unsupported blocksize for fs encryption");
4258 		goto failed_mount_wq;
4259 	}
4260 
4261 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4262 	    !ext4_has_feature_encrypt(sb)) {
4263 		ext4_set_feature_encrypt(sb);
4264 		ext4_commit_super(sb, 1);
4265 	}
4266 
4267 	/*
4268 	 * Get the # of file system overhead blocks from the
4269 	 * superblock if present.
4270 	 */
4271 	if (es->s_overhead_clusters)
4272 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4273 	else {
4274 		err = ext4_calculate_overhead(sb);
4275 		if (err)
4276 			goto failed_mount_wq;
4277 	}
4278 
4279 	/*
4280 	 * The maximum number of concurrent works can be high and
4281 	 * concurrency isn't really necessary.  Limit it to 1.
4282 	 */
4283 	EXT4_SB(sb)->rsv_conversion_wq =
4284 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4285 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4286 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4287 		ret = -ENOMEM;
4288 		goto failed_mount4;
4289 	}
4290 
4291 	/*
4292 	 * The jbd2_journal_load will have done any necessary log recovery,
4293 	 * so we can safely mount the rest of the filesystem now.
4294 	 */
4295 
4296 	root = ext4_iget(sb, EXT4_ROOT_INO);
4297 	if (IS_ERR(root)) {
4298 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4299 		ret = PTR_ERR(root);
4300 		root = NULL;
4301 		goto failed_mount4;
4302 	}
4303 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4304 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4305 		iput(root);
4306 		goto failed_mount4;
4307 	}
4308 	sb->s_root = d_make_root(root);
4309 	if (!sb->s_root) {
4310 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4311 		ret = -ENOMEM;
4312 		goto failed_mount4;
4313 	}
4314 
4315 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4316 	if (ret == -EROFS) {
4317 		sb->s_flags |= SB_RDONLY;
4318 		ret = 0;
4319 	} else if (ret)
4320 		goto failed_mount4a;
4321 
4322 	/* determine the minimum size of new large inodes, if present */
4323 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4324 	    sbi->s_want_extra_isize == 0) {
4325 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4326 						     EXT4_GOOD_OLD_INODE_SIZE;
4327 		if (ext4_has_feature_extra_isize(sb)) {
4328 			if (sbi->s_want_extra_isize <
4329 			    le16_to_cpu(es->s_want_extra_isize))
4330 				sbi->s_want_extra_isize =
4331 					le16_to_cpu(es->s_want_extra_isize);
4332 			if (sbi->s_want_extra_isize <
4333 			    le16_to_cpu(es->s_min_extra_isize))
4334 				sbi->s_want_extra_isize =
4335 					le16_to_cpu(es->s_min_extra_isize);
4336 		}
4337 	}
4338 	/* Check if enough inode space is available */
4339 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4340 							sbi->s_inode_size) {
4341 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4342 						       EXT4_GOOD_OLD_INODE_SIZE;
4343 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4344 			 "available");
4345 	}
4346 
4347 	ext4_set_resv_clusters(sb);
4348 
4349 	err = ext4_setup_system_zone(sb);
4350 	if (err) {
4351 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4352 			 "zone (%d)", err);
4353 		goto failed_mount4a;
4354 	}
4355 
4356 	ext4_ext_init(sb);
4357 	err = ext4_mb_init(sb);
4358 	if (err) {
4359 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4360 			 err);
4361 		goto failed_mount5;
4362 	}
4363 
4364 	block = ext4_count_free_clusters(sb);
4365 	ext4_free_blocks_count_set(sbi->s_es,
4366 				   EXT4_C2B(sbi, block));
4367 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4368 				  GFP_KERNEL);
4369 	if (!err) {
4370 		unsigned long freei = ext4_count_free_inodes(sb);
4371 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4372 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4373 					  GFP_KERNEL);
4374 	}
4375 	if (!err)
4376 		err = percpu_counter_init(&sbi->s_dirs_counter,
4377 					  ext4_count_dirs(sb), GFP_KERNEL);
4378 	if (!err)
4379 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4380 					  GFP_KERNEL);
4381 	if (!err)
4382 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4383 
4384 	if (err) {
4385 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4386 		goto failed_mount6;
4387 	}
4388 
4389 	if (ext4_has_feature_flex_bg(sb))
4390 		if (!ext4_fill_flex_info(sb)) {
4391 			ext4_msg(sb, KERN_ERR,
4392 			       "unable to initialize "
4393 			       "flex_bg meta info!");
4394 			goto failed_mount6;
4395 		}
4396 
4397 	err = ext4_register_li_request(sb, first_not_zeroed);
4398 	if (err)
4399 		goto failed_mount6;
4400 
4401 	err = ext4_register_sysfs(sb);
4402 	if (err)
4403 		goto failed_mount7;
4404 
4405 #ifdef CONFIG_QUOTA
4406 	/* Enable quota usage during mount. */
4407 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4408 		err = ext4_enable_quotas(sb);
4409 		if (err)
4410 			goto failed_mount8;
4411 	}
4412 #endif  /* CONFIG_QUOTA */
4413 
4414 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4415 	ext4_orphan_cleanup(sb, es);
4416 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4417 	if (needs_recovery) {
4418 		ext4_msg(sb, KERN_INFO, "recovery complete");
4419 		ext4_mark_recovery_complete(sb, es);
4420 	}
4421 	if (EXT4_SB(sb)->s_journal) {
4422 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4423 			descr = " journalled data mode";
4424 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4425 			descr = " ordered data mode";
4426 		else
4427 			descr = " writeback data mode";
4428 	} else
4429 		descr = "out journal";
4430 
4431 	if (test_opt(sb, DISCARD)) {
4432 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4433 		if (!blk_queue_discard(q))
4434 			ext4_msg(sb, KERN_WARNING,
4435 				 "mounting with \"discard\" option, but "
4436 				 "the device does not support discard");
4437 	}
4438 
4439 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4440 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4441 			 "Opts: %.*s%s%s", descr,
4442 			 (int) sizeof(sbi->s_es->s_mount_opts),
4443 			 sbi->s_es->s_mount_opts,
4444 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4445 
4446 	if (es->s_error_count)
4447 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4448 
4449 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4450 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4451 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4452 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4453 
4454 	kfree(orig_data);
4455 	return 0;
4456 
4457 cantfind_ext4:
4458 	if (!silent)
4459 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4460 	goto failed_mount;
4461 
4462 #ifdef CONFIG_QUOTA
4463 failed_mount8:
4464 	ext4_unregister_sysfs(sb);
4465 #endif
4466 failed_mount7:
4467 	ext4_unregister_li_request(sb);
4468 failed_mount6:
4469 	ext4_mb_release(sb);
4470 	if (sbi->s_flex_groups)
4471 		kvfree(sbi->s_flex_groups);
4472 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4473 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4474 	percpu_counter_destroy(&sbi->s_dirs_counter);
4475 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4476 failed_mount5:
4477 	ext4_ext_release(sb);
4478 	ext4_release_system_zone(sb);
4479 failed_mount4a:
4480 	dput(sb->s_root);
4481 	sb->s_root = NULL;
4482 failed_mount4:
4483 	ext4_msg(sb, KERN_ERR, "mount failed");
4484 	if (EXT4_SB(sb)->rsv_conversion_wq)
4485 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4486 failed_mount_wq:
4487 	if (sbi->s_ea_inode_cache) {
4488 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4489 		sbi->s_ea_inode_cache = NULL;
4490 	}
4491 	if (sbi->s_ea_block_cache) {
4492 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4493 		sbi->s_ea_block_cache = NULL;
4494 	}
4495 	if (sbi->s_journal) {
4496 		jbd2_journal_destroy(sbi->s_journal);
4497 		sbi->s_journal = NULL;
4498 	}
4499 failed_mount3a:
4500 	ext4_es_unregister_shrinker(sbi);
4501 failed_mount3:
4502 	del_timer_sync(&sbi->s_err_report);
4503 	if (sbi->s_mmp_tsk)
4504 		kthread_stop(sbi->s_mmp_tsk);
4505 failed_mount2:
4506 	for (i = 0; i < db_count; i++)
4507 		brelse(sbi->s_group_desc[i]);
4508 	kvfree(sbi->s_group_desc);
4509 failed_mount:
4510 	if (sbi->s_chksum_driver)
4511 		crypto_free_shash(sbi->s_chksum_driver);
4512 #ifdef CONFIG_QUOTA
4513 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4514 		kfree(sbi->s_qf_names[i]);
4515 #endif
4516 	ext4_blkdev_remove(sbi);
4517 	brelse(bh);
4518 out_fail:
4519 	sb->s_fs_info = NULL;
4520 	kfree(sbi->s_blockgroup_lock);
4521 out_free_base:
4522 	kfree(sbi);
4523 	kfree(orig_data);
4524 	fs_put_dax(dax_dev);
4525 	return err ? err : ret;
4526 }
4527 
4528 /*
4529  * Setup any per-fs journal parameters now.  We'll do this both on
4530  * initial mount, once the journal has been initialised but before we've
4531  * done any recovery; and again on any subsequent remount.
4532  */
4533 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4534 {
4535 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4536 
4537 	journal->j_commit_interval = sbi->s_commit_interval;
4538 	journal->j_min_batch_time = sbi->s_min_batch_time;
4539 	journal->j_max_batch_time = sbi->s_max_batch_time;
4540 
4541 	write_lock(&journal->j_state_lock);
4542 	if (test_opt(sb, BARRIER))
4543 		journal->j_flags |= JBD2_BARRIER;
4544 	else
4545 		journal->j_flags &= ~JBD2_BARRIER;
4546 	if (test_opt(sb, DATA_ERR_ABORT))
4547 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4548 	else
4549 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4550 	write_unlock(&journal->j_state_lock);
4551 }
4552 
4553 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4554 					     unsigned int journal_inum)
4555 {
4556 	struct inode *journal_inode;
4557 
4558 	/*
4559 	 * Test for the existence of a valid inode on disk.  Bad things
4560 	 * happen if we iget() an unused inode, as the subsequent iput()
4561 	 * will try to delete it.
4562 	 */
4563 	journal_inode = ext4_iget(sb, journal_inum);
4564 	if (IS_ERR(journal_inode)) {
4565 		ext4_msg(sb, KERN_ERR, "no journal found");
4566 		return NULL;
4567 	}
4568 	if (!journal_inode->i_nlink) {
4569 		make_bad_inode(journal_inode);
4570 		iput(journal_inode);
4571 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4572 		return NULL;
4573 	}
4574 
4575 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4576 		  journal_inode, journal_inode->i_size);
4577 	if (!S_ISREG(journal_inode->i_mode)) {
4578 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4579 		iput(journal_inode);
4580 		return NULL;
4581 	}
4582 	return journal_inode;
4583 }
4584 
4585 static journal_t *ext4_get_journal(struct super_block *sb,
4586 				   unsigned int journal_inum)
4587 {
4588 	struct inode *journal_inode;
4589 	journal_t *journal;
4590 
4591 	BUG_ON(!ext4_has_feature_journal(sb));
4592 
4593 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4594 	if (!journal_inode)
4595 		return NULL;
4596 
4597 	journal = jbd2_journal_init_inode(journal_inode);
4598 	if (!journal) {
4599 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4600 		iput(journal_inode);
4601 		return NULL;
4602 	}
4603 	journal->j_private = sb;
4604 	ext4_init_journal_params(sb, journal);
4605 	return journal;
4606 }
4607 
4608 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4609 				       dev_t j_dev)
4610 {
4611 	struct buffer_head *bh;
4612 	journal_t *journal;
4613 	ext4_fsblk_t start;
4614 	ext4_fsblk_t len;
4615 	int hblock, blocksize;
4616 	ext4_fsblk_t sb_block;
4617 	unsigned long offset;
4618 	struct ext4_super_block *es;
4619 	struct block_device *bdev;
4620 
4621 	BUG_ON(!ext4_has_feature_journal(sb));
4622 
4623 	bdev = ext4_blkdev_get(j_dev, sb);
4624 	if (bdev == NULL)
4625 		return NULL;
4626 
4627 	blocksize = sb->s_blocksize;
4628 	hblock = bdev_logical_block_size(bdev);
4629 	if (blocksize < hblock) {
4630 		ext4_msg(sb, KERN_ERR,
4631 			"blocksize too small for journal device");
4632 		goto out_bdev;
4633 	}
4634 
4635 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4636 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4637 	set_blocksize(bdev, blocksize);
4638 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4639 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4640 		       "external journal");
4641 		goto out_bdev;
4642 	}
4643 
4644 	es = (struct ext4_super_block *) (bh->b_data + offset);
4645 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4646 	    !(le32_to_cpu(es->s_feature_incompat) &
4647 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4648 		ext4_msg(sb, KERN_ERR, "external journal has "
4649 					"bad superblock");
4650 		brelse(bh);
4651 		goto out_bdev;
4652 	}
4653 
4654 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4655 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4656 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4657 		ext4_msg(sb, KERN_ERR, "external journal has "
4658 				       "corrupt superblock");
4659 		brelse(bh);
4660 		goto out_bdev;
4661 	}
4662 
4663 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4664 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4665 		brelse(bh);
4666 		goto out_bdev;
4667 	}
4668 
4669 	len = ext4_blocks_count(es);
4670 	start = sb_block + 1;
4671 	brelse(bh);	/* we're done with the superblock */
4672 
4673 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4674 					start, len, blocksize);
4675 	if (!journal) {
4676 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4677 		goto out_bdev;
4678 	}
4679 	journal->j_private = sb;
4680 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4681 	wait_on_buffer(journal->j_sb_buffer);
4682 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4683 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4684 		goto out_journal;
4685 	}
4686 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4687 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4688 					"user (unsupported) - %d",
4689 			be32_to_cpu(journal->j_superblock->s_nr_users));
4690 		goto out_journal;
4691 	}
4692 	EXT4_SB(sb)->journal_bdev = bdev;
4693 	ext4_init_journal_params(sb, journal);
4694 	return journal;
4695 
4696 out_journal:
4697 	jbd2_journal_destroy(journal);
4698 out_bdev:
4699 	ext4_blkdev_put(bdev);
4700 	return NULL;
4701 }
4702 
4703 static int ext4_load_journal(struct super_block *sb,
4704 			     struct ext4_super_block *es,
4705 			     unsigned long journal_devnum)
4706 {
4707 	journal_t *journal;
4708 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4709 	dev_t journal_dev;
4710 	int err = 0;
4711 	int really_read_only;
4712 
4713 	BUG_ON(!ext4_has_feature_journal(sb));
4714 
4715 	if (journal_devnum &&
4716 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4717 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4718 			"numbers have changed");
4719 		journal_dev = new_decode_dev(journal_devnum);
4720 	} else
4721 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4722 
4723 	really_read_only = bdev_read_only(sb->s_bdev);
4724 
4725 	/*
4726 	 * Are we loading a blank journal or performing recovery after a
4727 	 * crash?  For recovery, we need to check in advance whether we
4728 	 * can get read-write access to the device.
4729 	 */
4730 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4731 		if (sb_rdonly(sb)) {
4732 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4733 					"required on readonly filesystem");
4734 			if (really_read_only) {
4735 				ext4_msg(sb, KERN_ERR, "write access "
4736 					"unavailable, cannot proceed "
4737 					"(try mounting with noload)");
4738 				return -EROFS;
4739 			}
4740 			ext4_msg(sb, KERN_INFO, "write access will "
4741 			       "be enabled during recovery");
4742 		}
4743 	}
4744 
4745 	if (journal_inum && journal_dev) {
4746 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4747 		       "and inode journals!");
4748 		return -EINVAL;
4749 	}
4750 
4751 	if (journal_inum) {
4752 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4753 			return -EINVAL;
4754 	} else {
4755 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4756 			return -EINVAL;
4757 	}
4758 
4759 	if (!(journal->j_flags & JBD2_BARRIER))
4760 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4761 
4762 	if (!ext4_has_feature_journal_needs_recovery(sb))
4763 		err = jbd2_journal_wipe(journal, !really_read_only);
4764 	if (!err) {
4765 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4766 		if (save)
4767 			memcpy(save, ((char *) es) +
4768 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4769 		err = jbd2_journal_load(journal);
4770 		if (save)
4771 			memcpy(((char *) es) + EXT4_S_ERR_START,
4772 			       save, EXT4_S_ERR_LEN);
4773 		kfree(save);
4774 	}
4775 
4776 	if (err) {
4777 		ext4_msg(sb, KERN_ERR, "error loading journal");
4778 		jbd2_journal_destroy(journal);
4779 		return err;
4780 	}
4781 
4782 	EXT4_SB(sb)->s_journal = journal;
4783 	ext4_clear_journal_err(sb, es);
4784 
4785 	if (!really_read_only && journal_devnum &&
4786 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4787 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4788 
4789 		/* Make sure we flush the recovery flag to disk. */
4790 		ext4_commit_super(sb, 1);
4791 	}
4792 
4793 	return 0;
4794 }
4795 
4796 static int ext4_commit_super(struct super_block *sb, int sync)
4797 {
4798 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4799 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4800 	int error = 0;
4801 
4802 	if (!sbh || block_device_ejected(sb))
4803 		return error;
4804 
4805 	/*
4806 	 * The superblock bh should be mapped, but it might not be if the
4807 	 * device was hot-removed. Not much we can do but fail the I/O.
4808 	 */
4809 	if (!buffer_mapped(sbh))
4810 		return error;
4811 
4812 	/*
4813 	 * If the file system is mounted read-only, don't update the
4814 	 * superblock write time.  This avoids updating the superblock
4815 	 * write time when we are mounting the root file system
4816 	 * read/only but we need to replay the journal; at that point,
4817 	 * for people who are east of GMT and who make their clock
4818 	 * tick in localtime for Windows bug-for-bug compatibility,
4819 	 * the clock is set in the future, and this will cause e2fsck
4820 	 * to complain and force a full file system check.
4821 	 */
4822 	if (!(sb->s_flags & SB_RDONLY))
4823 		es->s_wtime = cpu_to_le32(get_seconds());
4824 	if (sb->s_bdev->bd_part)
4825 		es->s_kbytes_written =
4826 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4827 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4828 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4829 	else
4830 		es->s_kbytes_written =
4831 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4832 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4833 		ext4_free_blocks_count_set(es,
4834 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4835 				&EXT4_SB(sb)->s_freeclusters_counter)));
4836 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4837 		es->s_free_inodes_count =
4838 			cpu_to_le32(percpu_counter_sum_positive(
4839 				&EXT4_SB(sb)->s_freeinodes_counter));
4840 	BUFFER_TRACE(sbh, "marking dirty");
4841 	ext4_superblock_csum_set(sb);
4842 	if (sync)
4843 		lock_buffer(sbh);
4844 	if (buffer_write_io_error(sbh)) {
4845 		/*
4846 		 * Oh, dear.  A previous attempt to write the
4847 		 * superblock failed.  This could happen because the
4848 		 * USB device was yanked out.  Or it could happen to
4849 		 * be a transient write error and maybe the block will
4850 		 * be remapped.  Nothing we can do but to retry the
4851 		 * write and hope for the best.
4852 		 */
4853 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4854 		       "superblock detected");
4855 		clear_buffer_write_io_error(sbh);
4856 		set_buffer_uptodate(sbh);
4857 	}
4858 	mark_buffer_dirty(sbh);
4859 	if (sync) {
4860 		unlock_buffer(sbh);
4861 		error = __sync_dirty_buffer(sbh,
4862 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4863 		if (buffer_write_io_error(sbh)) {
4864 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4865 			       "superblock");
4866 			clear_buffer_write_io_error(sbh);
4867 			set_buffer_uptodate(sbh);
4868 		}
4869 	}
4870 	return error;
4871 }
4872 
4873 /*
4874  * Have we just finished recovery?  If so, and if we are mounting (or
4875  * remounting) the filesystem readonly, then we will end up with a
4876  * consistent fs on disk.  Record that fact.
4877  */
4878 static void ext4_mark_recovery_complete(struct super_block *sb,
4879 					struct ext4_super_block *es)
4880 {
4881 	journal_t *journal = EXT4_SB(sb)->s_journal;
4882 
4883 	if (!ext4_has_feature_journal(sb)) {
4884 		BUG_ON(journal != NULL);
4885 		return;
4886 	}
4887 	jbd2_journal_lock_updates(journal);
4888 	if (jbd2_journal_flush(journal) < 0)
4889 		goto out;
4890 
4891 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
4892 		ext4_clear_feature_journal_needs_recovery(sb);
4893 		ext4_commit_super(sb, 1);
4894 	}
4895 
4896 out:
4897 	jbd2_journal_unlock_updates(journal);
4898 }
4899 
4900 /*
4901  * If we are mounting (or read-write remounting) a filesystem whose journal
4902  * has recorded an error from a previous lifetime, move that error to the
4903  * main filesystem now.
4904  */
4905 static void ext4_clear_journal_err(struct super_block *sb,
4906 				   struct ext4_super_block *es)
4907 {
4908 	journal_t *journal;
4909 	int j_errno;
4910 	const char *errstr;
4911 
4912 	BUG_ON(!ext4_has_feature_journal(sb));
4913 
4914 	journal = EXT4_SB(sb)->s_journal;
4915 
4916 	/*
4917 	 * Now check for any error status which may have been recorded in the
4918 	 * journal by a prior ext4_error() or ext4_abort()
4919 	 */
4920 
4921 	j_errno = jbd2_journal_errno(journal);
4922 	if (j_errno) {
4923 		char nbuf[16];
4924 
4925 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4926 		ext4_warning(sb, "Filesystem error recorded "
4927 			     "from previous mount: %s", errstr);
4928 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4929 
4930 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4931 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4932 		ext4_commit_super(sb, 1);
4933 
4934 		jbd2_journal_clear_err(journal);
4935 		jbd2_journal_update_sb_errno(journal);
4936 	}
4937 }
4938 
4939 /*
4940  * Force the running and committing transactions to commit,
4941  * and wait on the commit.
4942  */
4943 int ext4_force_commit(struct super_block *sb)
4944 {
4945 	journal_t *journal;
4946 
4947 	if (sb_rdonly(sb))
4948 		return 0;
4949 
4950 	journal = EXT4_SB(sb)->s_journal;
4951 	return ext4_journal_force_commit(journal);
4952 }
4953 
4954 static int ext4_sync_fs(struct super_block *sb, int wait)
4955 {
4956 	int ret = 0;
4957 	tid_t target;
4958 	bool needs_barrier = false;
4959 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4960 
4961 	if (unlikely(ext4_forced_shutdown(sbi)))
4962 		return 0;
4963 
4964 	trace_ext4_sync_fs(sb, wait);
4965 	flush_workqueue(sbi->rsv_conversion_wq);
4966 	/*
4967 	 * Writeback quota in non-journalled quota case - journalled quota has
4968 	 * no dirty dquots
4969 	 */
4970 	dquot_writeback_dquots(sb, -1);
4971 	/*
4972 	 * Data writeback is possible w/o journal transaction, so barrier must
4973 	 * being sent at the end of the function. But we can skip it if
4974 	 * transaction_commit will do it for us.
4975 	 */
4976 	if (sbi->s_journal) {
4977 		target = jbd2_get_latest_transaction(sbi->s_journal);
4978 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4979 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4980 			needs_barrier = true;
4981 
4982 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4983 			if (wait)
4984 				ret = jbd2_log_wait_commit(sbi->s_journal,
4985 							   target);
4986 		}
4987 	} else if (wait && test_opt(sb, BARRIER))
4988 		needs_barrier = true;
4989 	if (needs_barrier) {
4990 		int err;
4991 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4992 		if (!ret)
4993 			ret = err;
4994 	}
4995 
4996 	return ret;
4997 }
4998 
4999 /*
5000  * LVM calls this function before a (read-only) snapshot is created.  This
5001  * gives us a chance to flush the journal completely and mark the fs clean.
5002  *
5003  * Note that only this function cannot bring a filesystem to be in a clean
5004  * state independently. It relies on upper layer to stop all data & metadata
5005  * modifications.
5006  */
5007 static int ext4_freeze(struct super_block *sb)
5008 {
5009 	int error = 0;
5010 	journal_t *journal;
5011 
5012 	if (sb_rdonly(sb))
5013 		return 0;
5014 
5015 	journal = EXT4_SB(sb)->s_journal;
5016 
5017 	if (journal) {
5018 		/* Now we set up the journal barrier. */
5019 		jbd2_journal_lock_updates(journal);
5020 
5021 		/*
5022 		 * Don't clear the needs_recovery flag if we failed to
5023 		 * flush the journal.
5024 		 */
5025 		error = jbd2_journal_flush(journal);
5026 		if (error < 0)
5027 			goto out;
5028 
5029 		/* Journal blocked and flushed, clear needs_recovery flag. */
5030 		ext4_clear_feature_journal_needs_recovery(sb);
5031 	}
5032 
5033 	error = ext4_commit_super(sb, 1);
5034 out:
5035 	if (journal)
5036 		/* we rely on upper layer to stop further updates */
5037 		jbd2_journal_unlock_updates(journal);
5038 	return error;
5039 }
5040 
5041 /*
5042  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5043  * flag here, even though the filesystem is not technically dirty yet.
5044  */
5045 static int ext4_unfreeze(struct super_block *sb)
5046 {
5047 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5048 		return 0;
5049 
5050 	if (EXT4_SB(sb)->s_journal) {
5051 		/* Reset the needs_recovery flag before the fs is unlocked. */
5052 		ext4_set_feature_journal_needs_recovery(sb);
5053 	}
5054 
5055 	ext4_commit_super(sb, 1);
5056 	return 0;
5057 }
5058 
5059 /*
5060  * Structure to save mount options for ext4_remount's benefit
5061  */
5062 struct ext4_mount_options {
5063 	unsigned long s_mount_opt;
5064 	unsigned long s_mount_opt2;
5065 	kuid_t s_resuid;
5066 	kgid_t s_resgid;
5067 	unsigned long s_commit_interval;
5068 	u32 s_min_batch_time, s_max_batch_time;
5069 #ifdef CONFIG_QUOTA
5070 	int s_jquota_fmt;
5071 	char *s_qf_names[EXT4_MAXQUOTAS];
5072 #endif
5073 };
5074 
5075 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5076 {
5077 	struct ext4_super_block *es;
5078 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5079 	unsigned long old_sb_flags;
5080 	struct ext4_mount_options old_opts;
5081 	int enable_quota = 0;
5082 	ext4_group_t g;
5083 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5084 	int err = 0;
5085 #ifdef CONFIG_QUOTA
5086 	int i, j;
5087 #endif
5088 	char *orig_data = kstrdup(data, GFP_KERNEL);
5089 
5090 	/* Store the original options */
5091 	old_sb_flags = sb->s_flags;
5092 	old_opts.s_mount_opt = sbi->s_mount_opt;
5093 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5094 	old_opts.s_resuid = sbi->s_resuid;
5095 	old_opts.s_resgid = sbi->s_resgid;
5096 	old_opts.s_commit_interval = sbi->s_commit_interval;
5097 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5098 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5099 #ifdef CONFIG_QUOTA
5100 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5101 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5102 		if (sbi->s_qf_names[i]) {
5103 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
5104 							 GFP_KERNEL);
5105 			if (!old_opts.s_qf_names[i]) {
5106 				for (j = 0; j < i; j++)
5107 					kfree(old_opts.s_qf_names[j]);
5108 				kfree(orig_data);
5109 				return -ENOMEM;
5110 			}
5111 		} else
5112 			old_opts.s_qf_names[i] = NULL;
5113 #endif
5114 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5115 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5116 
5117 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5118 		err = -EINVAL;
5119 		goto restore_opts;
5120 	}
5121 
5122 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5123 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5124 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5125 			 "during remount not supported; ignoring");
5126 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5127 	}
5128 
5129 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5130 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5131 			ext4_msg(sb, KERN_ERR, "can't mount with "
5132 				 "both data=journal and delalloc");
5133 			err = -EINVAL;
5134 			goto restore_opts;
5135 		}
5136 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5137 			ext4_msg(sb, KERN_ERR, "can't mount with "
5138 				 "both data=journal and dioread_nolock");
5139 			err = -EINVAL;
5140 			goto restore_opts;
5141 		}
5142 		if (test_opt(sb, DAX)) {
5143 			ext4_msg(sb, KERN_ERR, "can't mount with "
5144 				 "both data=journal and dax");
5145 			err = -EINVAL;
5146 			goto restore_opts;
5147 		}
5148 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5149 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5150 			ext4_msg(sb, KERN_ERR, "can't mount with "
5151 				"journal_async_commit in data=ordered mode");
5152 			err = -EINVAL;
5153 			goto restore_opts;
5154 		}
5155 	}
5156 
5157 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5158 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5159 		err = -EINVAL;
5160 		goto restore_opts;
5161 	}
5162 
5163 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5164 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5165 			"dax flag with busy inodes while remounting");
5166 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5167 	}
5168 
5169 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5170 		ext4_abort(sb, "Abort forced by user");
5171 
5172 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5173 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5174 
5175 	es = sbi->s_es;
5176 
5177 	if (sbi->s_journal) {
5178 		ext4_init_journal_params(sb, sbi->s_journal);
5179 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5180 	}
5181 
5182 	if (*flags & SB_LAZYTIME)
5183 		sb->s_flags |= SB_LAZYTIME;
5184 
5185 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5186 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5187 			err = -EROFS;
5188 			goto restore_opts;
5189 		}
5190 
5191 		if (*flags & SB_RDONLY) {
5192 			err = sync_filesystem(sb);
5193 			if (err < 0)
5194 				goto restore_opts;
5195 			err = dquot_suspend(sb, -1);
5196 			if (err < 0)
5197 				goto restore_opts;
5198 
5199 			/*
5200 			 * First of all, the unconditional stuff we have to do
5201 			 * to disable replay of the journal when we next remount
5202 			 */
5203 			sb->s_flags |= SB_RDONLY;
5204 
5205 			/*
5206 			 * OK, test if we are remounting a valid rw partition
5207 			 * readonly, and if so set the rdonly flag and then
5208 			 * mark the partition as valid again.
5209 			 */
5210 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5211 			    (sbi->s_mount_state & EXT4_VALID_FS))
5212 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5213 
5214 			if (sbi->s_journal)
5215 				ext4_mark_recovery_complete(sb, es);
5216 		} else {
5217 			/* Make sure we can mount this feature set readwrite */
5218 			if (ext4_has_feature_readonly(sb) ||
5219 			    !ext4_feature_set_ok(sb, 0)) {
5220 				err = -EROFS;
5221 				goto restore_opts;
5222 			}
5223 			/*
5224 			 * Make sure the group descriptor checksums
5225 			 * are sane.  If they aren't, refuse to remount r/w.
5226 			 */
5227 			for (g = 0; g < sbi->s_groups_count; g++) {
5228 				struct ext4_group_desc *gdp =
5229 					ext4_get_group_desc(sb, g, NULL);
5230 
5231 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5232 					ext4_msg(sb, KERN_ERR,
5233 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5234 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5235 					       le16_to_cpu(gdp->bg_checksum));
5236 					err = -EFSBADCRC;
5237 					goto restore_opts;
5238 				}
5239 			}
5240 
5241 			/*
5242 			 * If we have an unprocessed orphan list hanging
5243 			 * around from a previously readonly bdev mount,
5244 			 * require a full umount/remount for now.
5245 			 */
5246 			if (es->s_last_orphan) {
5247 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5248 				       "remount RDWR because of unprocessed "
5249 				       "orphan inode list.  Please "
5250 				       "umount/remount instead");
5251 				err = -EINVAL;
5252 				goto restore_opts;
5253 			}
5254 
5255 			/*
5256 			 * Mounting a RDONLY partition read-write, so reread
5257 			 * and store the current valid flag.  (It may have
5258 			 * been changed by e2fsck since we originally mounted
5259 			 * the partition.)
5260 			 */
5261 			if (sbi->s_journal)
5262 				ext4_clear_journal_err(sb, es);
5263 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5264 
5265 			err = ext4_setup_super(sb, es, 0);
5266 			if (err)
5267 				goto restore_opts;
5268 
5269 			sb->s_flags &= ~SB_RDONLY;
5270 			if (ext4_has_feature_mmp(sb))
5271 				if (ext4_multi_mount_protect(sb,
5272 						le64_to_cpu(es->s_mmp_block))) {
5273 					err = -EROFS;
5274 					goto restore_opts;
5275 				}
5276 			enable_quota = 1;
5277 		}
5278 	}
5279 
5280 	/*
5281 	 * Reinitialize lazy itable initialization thread based on
5282 	 * current settings
5283 	 */
5284 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5285 		ext4_unregister_li_request(sb);
5286 	else {
5287 		ext4_group_t first_not_zeroed;
5288 		first_not_zeroed = ext4_has_uninit_itable(sb);
5289 		ext4_register_li_request(sb, first_not_zeroed);
5290 	}
5291 
5292 	ext4_setup_system_zone(sb);
5293 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5294 		err = ext4_commit_super(sb, 1);
5295 		if (err)
5296 			goto restore_opts;
5297 	}
5298 
5299 #ifdef CONFIG_QUOTA
5300 	/* Release old quota file names */
5301 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5302 		kfree(old_opts.s_qf_names[i]);
5303 	if (enable_quota) {
5304 		if (sb_any_quota_suspended(sb))
5305 			dquot_resume(sb, -1);
5306 		else if (ext4_has_feature_quota(sb)) {
5307 			err = ext4_enable_quotas(sb);
5308 			if (err)
5309 				goto restore_opts;
5310 		}
5311 	}
5312 #endif
5313 
5314 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5315 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5316 	kfree(orig_data);
5317 	return 0;
5318 
5319 restore_opts:
5320 	sb->s_flags = old_sb_flags;
5321 	sbi->s_mount_opt = old_opts.s_mount_opt;
5322 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5323 	sbi->s_resuid = old_opts.s_resuid;
5324 	sbi->s_resgid = old_opts.s_resgid;
5325 	sbi->s_commit_interval = old_opts.s_commit_interval;
5326 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5327 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5328 #ifdef CONFIG_QUOTA
5329 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5330 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5331 		kfree(sbi->s_qf_names[i]);
5332 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5333 	}
5334 #endif
5335 	kfree(orig_data);
5336 	return err;
5337 }
5338 
5339 #ifdef CONFIG_QUOTA
5340 static int ext4_statfs_project(struct super_block *sb,
5341 			       kprojid_t projid, struct kstatfs *buf)
5342 {
5343 	struct kqid qid;
5344 	struct dquot *dquot;
5345 	u64 limit;
5346 	u64 curblock;
5347 
5348 	qid = make_kqid_projid(projid);
5349 	dquot = dqget(sb, qid);
5350 	if (IS_ERR(dquot))
5351 		return PTR_ERR(dquot);
5352 	spin_lock(&dquot->dq_dqb_lock);
5353 
5354 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5355 		 dquot->dq_dqb.dqb_bsoftlimit :
5356 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5357 	if (limit && buf->f_blocks > limit) {
5358 		curblock = (dquot->dq_dqb.dqb_curspace +
5359 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5360 		buf->f_blocks = limit;
5361 		buf->f_bfree = buf->f_bavail =
5362 			(buf->f_blocks > curblock) ?
5363 			 (buf->f_blocks - curblock) : 0;
5364 	}
5365 
5366 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5367 		dquot->dq_dqb.dqb_isoftlimit :
5368 		dquot->dq_dqb.dqb_ihardlimit;
5369 	if (limit && buf->f_files > limit) {
5370 		buf->f_files = limit;
5371 		buf->f_ffree =
5372 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5373 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5374 	}
5375 
5376 	spin_unlock(&dquot->dq_dqb_lock);
5377 	dqput(dquot);
5378 	return 0;
5379 }
5380 #endif
5381 
5382 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5383 {
5384 	struct super_block *sb = dentry->d_sb;
5385 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5386 	struct ext4_super_block *es = sbi->s_es;
5387 	ext4_fsblk_t overhead = 0, resv_blocks;
5388 	u64 fsid;
5389 	s64 bfree;
5390 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5391 
5392 	if (!test_opt(sb, MINIX_DF))
5393 		overhead = sbi->s_overhead;
5394 
5395 	buf->f_type = EXT4_SUPER_MAGIC;
5396 	buf->f_bsize = sb->s_blocksize;
5397 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5398 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5399 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5400 	/* prevent underflow in case that few free space is available */
5401 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5402 	buf->f_bavail = buf->f_bfree -
5403 			(ext4_r_blocks_count(es) + resv_blocks);
5404 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5405 		buf->f_bavail = 0;
5406 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5407 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5408 	buf->f_namelen = EXT4_NAME_LEN;
5409 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5410 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5411 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5412 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5413 
5414 #ifdef CONFIG_QUOTA
5415 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5416 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5417 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5418 #endif
5419 	return 0;
5420 }
5421 
5422 
5423 #ifdef CONFIG_QUOTA
5424 
5425 /*
5426  * Helper functions so that transaction is started before we acquire dqio_sem
5427  * to keep correct lock ordering of transaction > dqio_sem
5428  */
5429 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5430 {
5431 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5432 }
5433 
5434 static int ext4_write_dquot(struct dquot *dquot)
5435 {
5436 	int ret, err;
5437 	handle_t *handle;
5438 	struct inode *inode;
5439 
5440 	inode = dquot_to_inode(dquot);
5441 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5442 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5443 	if (IS_ERR(handle))
5444 		return PTR_ERR(handle);
5445 	ret = dquot_commit(dquot);
5446 	err = ext4_journal_stop(handle);
5447 	if (!ret)
5448 		ret = err;
5449 	return ret;
5450 }
5451 
5452 static int ext4_acquire_dquot(struct dquot *dquot)
5453 {
5454 	int ret, err;
5455 	handle_t *handle;
5456 
5457 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5458 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5459 	if (IS_ERR(handle))
5460 		return PTR_ERR(handle);
5461 	ret = dquot_acquire(dquot);
5462 	err = ext4_journal_stop(handle);
5463 	if (!ret)
5464 		ret = err;
5465 	return ret;
5466 }
5467 
5468 static int ext4_release_dquot(struct dquot *dquot)
5469 {
5470 	int ret, err;
5471 	handle_t *handle;
5472 
5473 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5474 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5475 	if (IS_ERR(handle)) {
5476 		/* Release dquot anyway to avoid endless cycle in dqput() */
5477 		dquot_release(dquot);
5478 		return PTR_ERR(handle);
5479 	}
5480 	ret = dquot_release(dquot);
5481 	err = ext4_journal_stop(handle);
5482 	if (!ret)
5483 		ret = err;
5484 	return ret;
5485 }
5486 
5487 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5488 {
5489 	struct super_block *sb = dquot->dq_sb;
5490 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5491 
5492 	/* Are we journaling quotas? */
5493 	if (ext4_has_feature_quota(sb) ||
5494 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5495 		dquot_mark_dquot_dirty(dquot);
5496 		return ext4_write_dquot(dquot);
5497 	} else {
5498 		return dquot_mark_dquot_dirty(dquot);
5499 	}
5500 }
5501 
5502 static int ext4_write_info(struct super_block *sb, int type)
5503 {
5504 	int ret, err;
5505 	handle_t *handle;
5506 
5507 	/* Data block + inode block */
5508 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5509 	if (IS_ERR(handle))
5510 		return PTR_ERR(handle);
5511 	ret = dquot_commit_info(sb, type);
5512 	err = ext4_journal_stop(handle);
5513 	if (!ret)
5514 		ret = err;
5515 	return ret;
5516 }
5517 
5518 /*
5519  * Turn on quotas during mount time - we need to find
5520  * the quota file and such...
5521  */
5522 static int ext4_quota_on_mount(struct super_block *sb, int type)
5523 {
5524 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5525 					EXT4_SB(sb)->s_jquota_fmt, type);
5526 }
5527 
5528 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5529 {
5530 	struct ext4_inode_info *ei = EXT4_I(inode);
5531 
5532 	/* The first argument of lockdep_set_subclass has to be
5533 	 * *exactly* the same as the argument to init_rwsem() --- in
5534 	 * this case, in init_once() --- or lockdep gets unhappy
5535 	 * because the name of the lock is set using the
5536 	 * stringification of the argument to init_rwsem().
5537 	 */
5538 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5539 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5540 }
5541 
5542 /*
5543  * Standard function to be called on quota_on
5544  */
5545 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5546 			 const struct path *path)
5547 {
5548 	int err;
5549 
5550 	if (!test_opt(sb, QUOTA))
5551 		return -EINVAL;
5552 
5553 	/* Quotafile not on the same filesystem? */
5554 	if (path->dentry->d_sb != sb)
5555 		return -EXDEV;
5556 	/* Journaling quota? */
5557 	if (EXT4_SB(sb)->s_qf_names[type]) {
5558 		/* Quotafile not in fs root? */
5559 		if (path->dentry->d_parent != sb->s_root)
5560 			ext4_msg(sb, KERN_WARNING,
5561 				"Quota file not on filesystem root. "
5562 				"Journaled quota will not work");
5563 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5564 	} else {
5565 		/*
5566 		 * Clear the flag just in case mount options changed since
5567 		 * last time.
5568 		 */
5569 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5570 	}
5571 
5572 	/*
5573 	 * When we journal data on quota file, we have to flush journal to see
5574 	 * all updates to the file when we bypass pagecache...
5575 	 */
5576 	if (EXT4_SB(sb)->s_journal &&
5577 	    ext4_should_journal_data(d_inode(path->dentry))) {
5578 		/*
5579 		 * We don't need to lock updates but journal_flush() could
5580 		 * otherwise be livelocked...
5581 		 */
5582 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5583 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5584 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5585 		if (err)
5586 			return err;
5587 	}
5588 
5589 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5590 	err = dquot_quota_on(sb, type, format_id, path);
5591 	if (err) {
5592 		lockdep_set_quota_inode(path->dentry->d_inode,
5593 					     I_DATA_SEM_NORMAL);
5594 	} else {
5595 		struct inode *inode = d_inode(path->dentry);
5596 		handle_t *handle;
5597 
5598 		/*
5599 		 * Set inode flags to prevent userspace from messing with quota
5600 		 * files. If this fails, we return success anyway since quotas
5601 		 * are already enabled and this is not a hard failure.
5602 		 */
5603 		inode_lock(inode);
5604 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5605 		if (IS_ERR(handle))
5606 			goto unlock_inode;
5607 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5608 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5609 				S_NOATIME | S_IMMUTABLE);
5610 		ext4_mark_inode_dirty(handle, inode);
5611 		ext4_journal_stop(handle);
5612 	unlock_inode:
5613 		inode_unlock(inode);
5614 	}
5615 	return err;
5616 }
5617 
5618 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5619 			     unsigned int flags)
5620 {
5621 	int err;
5622 	struct inode *qf_inode;
5623 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5624 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5625 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5626 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5627 	};
5628 
5629 	BUG_ON(!ext4_has_feature_quota(sb));
5630 
5631 	if (!qf_inums[type])
5632 		return -EPERM;
5633 
5634 	qf_inode = ext4_iget(sb, qf_inums[type]);
5635 	if (IS_ERR(qf_inode)) {
5636 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5637 		return PTR_ERR(qf_inode);
5638 	}
5639 
5640 	/* Don't account quota for quota files to avoid recursion */
5641 	qf_inode->i_flags |= S_NOQUOTA;
5642 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5643 	err = dquot_enable(qf_inode, type, format_id, flags);
5644 	iput(qf_inode);
5645 	if (err)
5646 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5647 
5648 	return err;
5649 }
5650 
5651 /* Enable usage tracking for all quota types. */
5652 static int ext4_enable_quotas(struct super_block *sb)
5653 {
5654 	int type, err = 0;
5655 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5656 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5657 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5658 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5659 	};
5660 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5661 		test_opt(sb, USRQUOTA),
5662 		test_opt(sb, GRPQUOTA),
5663 		test_opt(sb, PRJQUOTA),
5664 	};
5665 
5666 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5667 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5668 		if (qf_inums[type]) {
5669 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5670 				DQUOT_USAGE_ENABLED |
5671 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5672 			if (err) {
5673 				for (type--; type >= 0; type--)
5674 					dquot_quota_off(sb, type);
5675 
5676 				ext4_warning(sb,
5677 					"Failed to enable quota tracking "
5678 					"(type=%d, err=%d). Please run "
5679 					"e2fsck to fix.", type, err);
5680 				return err;
5681 			}
5682 		}
5683 	}
5684 	return 0;
5685 }
5686 
5687 static int ext4_quota_off(struct super_block *sb, int type)
5688 {
5689 	struct inode *inode = sb_dqopt(sb)->files[type];
5690 	handle_t *handle;
5691 	int err;
5692 
5693 	/* Force all delayed allocation blocks to be allocated.
5694 	 * Caller already holds s_umount sem */
5695 	if (test_opt(sb, DELALLOC))
5696 		sync_filesystem(sb);
5697 
5698 	if (!inode || !igrab(inode))
5699 		goto out;
5700 
5701 	err = dquot_quota_off(sb, type);
5702 	if (err || ext4_has_feature_quota(sb))
5703 		goto out_put;
5704 
5705 	inode_lock(inode);
5706 	/*
5707 	 * Update modification times of quota files when userspace can
5708 	 * start looking at them. If we fail, we return success anyway since
5709 	 * this is not a hard failure and quotas are already disabled.
5710 	 */
5711 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5712 	if (IS_ERR(handle))
5713 		goto out_unlock;
5714 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5715 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5716 	inode->i_mtime = inode->i_ctime = current_time(inode);
5717 	ext4_mark_inode_dirty(handle, inode);
5718 	ext4_journal_stop(handle);
5719 out_unlock:
5720 	inode_unlock(inode);
5721 out_put:
5722 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5723 	iput(inode);
5724 	return err;
5725 out:
5726 	return dquot_quota_off(sb, type);
5727 }
5728 
5729 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5730  * acquiring the locks... As quota files are never truncated and quota code
5731  * itself serializes the operations (and no one else should touch the files)
5732  * we don't have to be afraid of races */
5733 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5734 			       size_t len, loff_t off)
5735 {
5736 	struct inode *inode = sb_dqopt(sb)->files[type];
5737 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5738 	int offset = off & (sb->s_blocksize - 1);
5739 	int tocopy;
5740 	size_t toread;
5741 	struct buffer_head *bh;
5742 	loff_t i_size = i_size_read(inode);
5743 
5744 	if (off > i_size)
5745 		return 0;
5746 	if (off+len > i_size)
5747 		len = i_size-off;
5748 	toread = len;
5749 	while (toread > 0) {
5750 		tocopy = sb->s_blocksize - offset < toread ?
5751 				sb->s_blocksize - offset : toread;
5752 		bh = ext4_bread(NULL, inode, blk, 0);
5753 		if (IS_ERR(bh))
5754 			return PTR_ERR(bh);
5755 		if (!bh)	/* A hole? */
5756 			memset(data, 0, tocopy);
5757 		else
5758 			memcpy(data, bh->b_data+offset, tocopy);
5759 		brelse(bh);
5760 		offset = 0;
5761 		toread -= tocopy;
5762 		data += tocopy;
5763 		blk++;
5764 	}
5765 	return len;
5766 }
5767 
5768 /* Write to quotafile (we know the transaction is already started and has
5769  * enough credits) */
5770 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5771 				const char *data, size_t len, loff_t off)
5772 {
5773 	struct inode *inode = sb_dqopt(sb)->files[type];
5774 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5775 	int err, offset = off & (sb->s_blocksize - 1);
5776 	int retries = 0;
5777 	struct buffer_head *bh;
5778 	handle_t *handle = journal_current_handle();
5779 
5780 	if (EXT4_SB(sb)->s_journal && !handle) {
5781 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5782 			" cancelled because transaction is not started",
5783 			(unsigned long long)off, (unsigned long long)len);
5784 		return -EIO;
5785 	}
5786 	/*
5787 	 * Since we account only one data block in transaction credits,
5788 	 * then it is impossible to cross a block boundary.
5789 	 */
5790 	if (sb->s_blocksize - offset < len) {
5791 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5792 			" cancelled because not block aligned",
5793 			(unsigned long long)off, (unsigned long long)len);
5794 		return -EIO;
5795 	}
5796 
5797 	do {
5798 		bh = ext4_bread(handle, inode, blk,
5799 				EXT4_GET_BLOCKS_CREATE |
5800 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5801 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5802 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5803 	if (IS_ERR(bh))
5804 		return PTR_ERR(bh);
5805 	if (!bh)
5806 		goto out;
5807 	BUFFER_TRACE(bh, "get write access");
5808 	err = ext4_journal_get_write_access(handle, bh);
5809 	if (err) {
5810 		brelse(bh);
5811 		return err;
5812 	}
5813 	lock_buffer(bh);
5814 	memcpy(bh->b_data+offset, data, len);
5815 	flush_dcache_page(bh->b_page);
5816 	unlock_buffer(bh);
5817 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5818 	brelse(bh);
5819 out:
5820 	if (inode->i_size < off + len) {
5821 		i_size_write(inode, off + len);
5822 		EXT4_I(inode)->i_disksize = inode->i_size;
5823 		ext4_mark_inode_dirty(handle, inode);
5824 	}
5825 	return len;
5826 }
5827 
5828 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5829 {
5830 	const struct quota_format_ops	*ops;
5831 
5832 	if (!sb_has_quota_loaded(sb, qid->type))
5833 		return -ESRCH;
5834 	ops = sb_dqopt(sb)->ops[qid->type];
5835 	if (!ops || !ops->get_next_id)
5836 		return -ENOSYS;
5837 	return dquot_get_next_id(sb, qid);
5838 }
5839 #endif
5840 
5841 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5842 		       const char *dev_name, void *data)
5843 {
5844 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5845 }
5846 
5847 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5848 static inline void register_as_ext2(void)
5849 {
5850 	int err = register_filesystem(&ext2_fs_type);
5851 	if (err)
5852 		printk(KERN_WARNING
5853 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5854 }
5855 
5856 static inline void unregister_as_ext2(void)
5857 {
5858 	unregister_filesystem(&ext2_fs_type);
5859 }
5860 
5861 static inline int ext2_feature_set_ok(struct super_block *sb)
5862 {
5863 	if (ext4_has_unknown_ext2_incompat_features(sb))
5864 		return 0;
5865 	if (sb_rdonly(sb))
5866 		return 1;
5867 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5868 		return 0;
5869 	return 1;
5870 }
5871 #else
5872 static inline void register_as_ext2(void) { }
5873 static inline void unregister_as_ext2(void) { }
5874 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5875 #endif
5876 
5877 static inline void register_as_ext3(void)
5878 {
5879 	int err = register_filesystem(&ext3_fs_type);
5880 	if (err)
5881 		printk(KERN_WARNING
5882 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5883 }
5884 
5885 static inline void unregister_as_ext3(void)
5886 {
5887 	unregister_filesystem(&ext3_fs_type);
5888 }
5889 
5890 static inline int ext3_feature_set_ok(struct super_block *sb)
5891 {
5892 	if (ext4_has_unknown_ext3_incompat_features(sb))
5893 		return 0;
5894 	if (!ext4_has_feature_journal(sb))
5895 		return 0;
5896 	if (sb_rdonly(sb))
5897 		return 1;
5898 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5899 		return 0;
5900 	return 1;
5901 }
5902 
5903 static struct file_system_type ext4_fs_type = {
5904 	.owner		= THIS_MODULE,
5905 	.name		= "ext4",
5906 	.mount		= ext4_mount,
5907 	.kill_sb	= kill_block_super,
5908 	.fs_flags	= FS_REQUIRES_DEV,
5909 };
5910 MODULE_ALIAS_FS("ext4");
5911 
5912 /* Shared across all ext4 file systems */
5913 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5914 
5915 static int __init ext4_init_fs(void)
5916 {
5917 	int i, err;
5918 
5919 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5920 	ext4_li_info = NULL;
5921 	mutex_init(&ext4_li_mtx);
5922 
5923 	/* Build-time check for flags consistency */
5924 	ext4_check_flag_values();
5925 
5926 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5927 		init_waitqueue_head(&ext4__ioend_wq[i]);
5928 
5929 	err = ext4_init_es();
5930 	if (err)
5931 		return err;
5932 
5933 	err = ext4_init_pageio();
5934 	if (err)
5935 		goto out5;
5936 
5937 	err = ext4_init_system_zone();
5938 	if (err)
5939 		goto out4;
5940 
5941 	err = ext4_init_sysfs();
5942 	if (err)
5943 		goto out3;
5944 
5945 	err = ext4_init_mballoc();
5946 	if (err)
5947 		goto out2;
5948 	err = init_inodecache();
5949 	if (err)
5950 		goto out1;
5951 	register_as_ext3();
5952 	register_as_ext2();
5953 	err = register_filesystem(&ext4_fs_type);
5954 	if (err)
5955 		goto out;
5956 
5957 	return 0;
5958 out:
5959 	unregister_as_ext2();
5960 	unregister_as_ext3();
5961 	destroy_inodecache();
5962 out1:
5963 	ext4_exit_mballoc();
5964 out2:
5965 	ext4_exit_sysfs();
5966 out3:
5967 	ext4_exit_system_zone();
5968 out4:
5969 	ext4_exit_pageio();
5970 out5:
5971 	ext4_exit_es();
5972 
5973 	return err;
5974 }
5975 
5976 static void __exit ext4_exit_fs(void)
5977 {
5978 	ext4_destroy_lazyinit_thread();
5979 	unregister_as_ext2();
5980 	unregister_as_ext3();
5981 	unregister_filesystem(&ext4_fs_type);
5982 	destroy_inodecache();
5983 	ext4_exit_mballoc();
5984 	ext4_exit_sysfs();
5985 	ext4_exit_system_zone();
5986 	ext4_exit_pageio();
5987 	ext4_exit_es();
5988 }
5989 
5990 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5991 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5992 MODULE_LICENSE("GPL");
5993 MODULE_SOFTDEP("pre: crc32c");
5994 module_init(ext4_init_fs)
5995 module_exit(ext4_exit_fs)
5996