xref: /openbmc/linux/fs/ext4/super.c (revision 110e6f26)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/slab.h>
25 #include <linux/init.h>
26 #include <linux/blkdev.h>
27 #include <linux/backing-dev.h>
28 #include <linux/parser.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/ctype.h>
38 #include <linux/log2.h>
39 #include <linux/crc16.h>
40 #include <linux/cleancache.h>
41 #include <asm/uaccess.h>
42 
43 #include <linux/kthread.h>
44 #include <linux/freezer.h>
45 
46 #include "ext4.h"
47 #include "ext4_extents.h"	/* Needed for trace points definition */
48 #include "ext4_jbd2.h"
49 #include "xattr.h"
50 #include "acl.h"
51 #include "mballoc.h"
52 
53 #define CREATE_TRACE_POINTS
54 #include <trace/events/ext4.h>
55 
56 static struct ext4_lazy_init *ext4_li_info;
57 static struct mutex ext4_li_mtx;
58 static struct ratelimit_state ext4_mount_msg_ratelimit;
59 
60 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
61 			     unsigned long journal_devnum);
62 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
63 static int ext4_commit_super(struct super_block *sb, int sync);
64 static void ext4_mark_recovery_complete(struct super_block *sb,
65 					struct ext4_super_block *es);
66 static void ext4_clear_journal_err(struct super_block *sb,
67 				   struct ext4_super_block *es);
68 static int ext4_sync_fs(struct super_block *sb, int wait);
69 static int ext4_remount(struct super_block *sb, int *flags, char *data);
70 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
71 static int ext4_unfreeze(struct super_block *sb);
72 static int ext4_freeze(struct super_block *sb);
73 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
74 		       const char *dev_name, void *data);
75 static inline int ext2_feature_set_ok(struct super_block *sb);
76 static inline int ext3_feature_set_ok(struct super_block *sb);
77 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
78 static void ext4_destroy_lazyinit_thread(void);
79 static void ext4_unregister_li_request(struct super_block *sb);
80 static void ext4_clear_request_list(void);
81 
82 /*
83  * Lock ordering
84  *
85  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
86  * i_mmap_rwsem (inode->i_mmap_rwsem)!
87  *
88  * page fault path:
89  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
90  *   page lock -> i_data_sem (rw)
91  *
92  * buffered write path:
93  * sb_start_write -> i_mutex -> mmap_sem
94  * sb_start_write -> i_mutex -> transaction start -> page lock ->
95  *   i_data_sem (rw)
96  *
97  * truncate:
98  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
99  *   i_mmap_rwsem (w) -> page lock
100  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
101  *   transaction start -> i_data_sem (rw)
102  *
103  * direct IO:
104  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
105  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
106  *   transaction start -> i_data_sem (rw)
107  *
108  * writepages:
109  * transaction start -> page lock(s) -> i_data_sem (rw)
110  */
111 
112 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
113 static struct file_system_type ext2_fs_type = {
114 	.owner		= THIS_MODULE,
115 	.name		= "ext2",
116 	.mount		= ext4_mount,
117 	.kill_sb	= kill_block_super,
118 	.fs_flags	= FS_REQUIRES_DEV,
119 };
120 MODULE_ALIAS_FS("ext2");
121 MODULE_ALIAS("ext2");
122 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
123 #else
124 #define IS_EXT2_SB(sb) (0)
125 #endif
126 
127 
128 static struct file_system_type ext3_fs_type = {
129 	.owner		= THIS_MODULE,
130 	.name		= "ext3",
131 	.mount		= ext4_mount,
132 	.kill_sb	= kill_block_super,
133 	.fs_flags	= FS_REQUIRES_DEV,
134 };
135 MODULE_ALIAS_FS("ext3");
136 MODULE_ALIAS("ext3");
137 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
138 
139 static int ext4_verify_csum_type(struct super_block *sb,
140 				 struct ext4_super_block *es)
141 {
142 	if (!ext4_has_feature_metadata_csum(sb))
143 		return 1;
144 
145 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
146 }
147 
148 static __le32 ext4_superblock_csum(struct super_block *sb,
149 				   struct ext4_super_block *es)
150 {
151 	struct ext4_sb_info *sbi = EXT4_SB(sb);
152 	int offset = offsetof(struct ext4_super_block, s_checksum);
153 	__u32 csum;
154 
155 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
156 
157 	return cpu_to_le32(csum);
158 }
159 
160 static int ext4_superblock_csum_verify(struct super_block *sb,
161 				       struct ext4_super_block *es)
162 {
163 	if (!ext4_has_metadata_csum(sb))
164 		return 1;
165 
166 	return es->s_checksum == ext4_superblock_csum(sb, es);
167 }
168 
169 void ext4_superblock_csum_set(struct super_block *sb)
170 {
171 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
172 
173 	if (!ext4_has_metadata_csum(sb))
174 		return;
175 
176 	es->s_checksum = ext4_superblock_csum(sb, es);
177 }
178 
179 void *ext4_kvmalloc(size_t size, gfp_t flags)
180 {
181 	void *ret;
182 
183 	ret = kmalloc(size, flags | __GFP_NOWARN);
184 	if (!ret)
185 		ret = __vmalloc(size, flags, PAGE_KERNEL);
186 	return ret;
187 }
188 
189 void *ext4_kvzalloc(size_t size, gfp_t flags)
190 {
191 	void *ret;
192 
193 	ret = kzalloc(size, flags | __GFP_NOWARN);
194 	if (!ret)
195 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
196 	return ret;
197 }
198 
199 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
200 			       struct ext4_group_desc *bg)
201 {
202 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
203 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
204 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
205 }
206 
207 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
208 			       struct ext4_group_desc *bg)
209 {
210 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
211 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
212 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
213 }
214 
215 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
216 			      struct ext4_group_desc *bg)
217 {
218 	return le32_to_cpu(bg->bg_inode_table_lo) |
219 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
220 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
221 }
222 
223 __u32 ext4_free_group_clusters(struct super_block *sb,
224 			       struct ext4_group_desc *bg)
225 {
226 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
227 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
228 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
229 }
230 
231 __u32 ext4_free_inodes_count(struct super_block *sb,
232 			      struct ext4_group_desc *bg)
233 {
234 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
235 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
236 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
237 }
238 
239 __u32 ext4_used_dirs_count(struct super_block *sb,
240 			      struct ext4_group_desc *bg)
241 {
242 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
243 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
244 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
245 }
246 
247 __u32 ext4_itable_unused_count(struct super_block *sb,
248 			      struct ext4_group_desc *bg)
249 {
250 	return le16_to_cpu(bg->bg_itable_unused_lo) |
251 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
252 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
253 }
254 
255 void ext4_block_bitmap_set(struct super_block *sb,
256 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
257 {
258 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
259 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
260 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
261 }
262 
263 void ext4_inode_bitmap_set(struct super_block *sb,
264 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
265 {
266 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
267 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
268 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
269 }
270 
271 void ext4_inode_table_set(struct super_block *sb,
272 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
273 {
274 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
275 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
276 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
277 }
278 
279 void ext4_free_group_clusters_set(struct super_block *sb,
280 				  struct ext4_group_desc *bg, __u32 count)
281 {
282 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
283 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
284 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
285 }
286 
287 void ext4_free_inodes_set(struct super_block *sb,
288 			  struct ext4_group_desc *bg, __u32 count)
289 {
290 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
291 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
292 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
293 }
294 
295 void ext4_used_dirs_set(struct super_block *sb,
296 			  struct ext4_group_desc *bg, __u32 count)
297 {
298 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
299 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
300 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
301 }
302 
303 void ext4_itable_unused_set(struct super_block *sb,
304 			  struct ext4_group_desc *bg, __u32 count)
305 {
306 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
307 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
308 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
309 }
310 
311 
312 static void __save_error_info(struct super_block *sb, const char *func,
313 			    unsigned int line)
314 {
315 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
316 
317 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
318 	if (bdev_read_only(sb->s_bdev))
319 		return;
320 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
321 	es->s_last_error_time = cpu_to_le32(get_seconds());
322 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
323 	es->s_last_error_line = cpu_to_le32(line);
324 	if (!es->s_first_error_time) {
325 		es->s_first_error_time = es->s_last_error_time;
326 		strncpy(es->s_first_error_func, func,
327 			sizeof(es->s_first_error_func));
328 		es->s_first_error_line = cpu_to_le32(line);
329 		es->s_first_error_ino = es->s_last_error_ino;
330 		es->s_first_error_block = es->s_last_error_block;
331 	}
332 	/*
333 	 * Start the daily error reporting function if it hasn't been
334 	 * started already
335 	 */
336 	if (!es->s_error_count)
337 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
338 	le32_add_cpu(&es->s_error_count, 1);
339 }
340 
341 static void save_error_info(struct super_block *sb, const char *func,
342 			    unsigned int line)
343 {
344 	__save_error_info(sb, func, line);
345 	ext4_commit_super(sb, 1);
346 }
347 
348 /*
349  * The del_gendisk() function uninitializes the disk-specific data
350  * structures, including the bdi structure, without telling anyone
351  * else.  Once this happens, any attempt to call mark_buffer_dirty()
352  * (for example, by ext4_commit_super), will cause a kernel OOPS.
353  * This is a kludge to prevent these oops until we can put in a proper
354  * hook in del_gendisk() to inform the VFS and file system layers.
355  */
356 static int block_device_ejected(struct super_block *sb)
357 {
358 	struct inode *bd_inode = sb->s_bdev->bd_inode;
359 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
360 
361 	return bdi->dev == NULL;
362 }
363 
364 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
365 {
366 	struct super_block		*sb = journal->j_private;
367 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
368 	int				error = is_journal_aborted(journal);
369 	struct ext4_journal_cb_entry	*jce;
370 
371 	BUG_ON(txn->t_state == T_FINISHED);
372 	spin_lock(&sbi->s_md_lock);
373 	while (!list_empty(&txn->t_private_list)) {
374 		jce = list_entry(txn->t_private_list.next,
375 				 struct ext4_journal_cb_entry, jce_list);
376 		list_del_init(&jce->jce_list);
377 		spin_unlock(&sbi->s_md_lock);
378 		jce->jce_func(sb, jce, error);
379 		spin_lock(&sbi->s_md_lock);
380 	}
381 	spin_unlock(&sbi->s_md_lock);
382 }
383 
384 /* Deal with the reporting of failure conditions on a filesystem such as
385  * inconsistencies detected or read IO failures.
386  *
387  * On ext2, we can store the error state of the filesystem in the
388  * superblock.  That is not possible on ext4, because we may have other
389  * write ordering constraints on the superblock which prevent us from
390  * writing it out straight away; and given that the journal is about to
391  * be aborted, we can't rely on the current, or future, transactions to
392  * write out the superblock safely.
393  *
394  * We'll just use the jbd2_journal_abort() error code to record an error in
395  * the journal instead.  On recovery, the journal will complain about
396  * that error until we've noted it down and cleared it.
397  */
398 
399 static void ext4_handle_error(struct super_block *sb)
400 {
401 	if (sb->s_flags & MS_RDONLY)
402 		return;
403 
404 	if (!test_opt(sb, ERRORS_CONT)) {
405 		journal_t *journal = EXT4_SB(sb)->s_journal;
406 
407 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
408 		if (journal)
409 			jbd2_journal_abort(journal, -EIO);
410 	}
411 	if (test_opt(sb, ERRORS_RO)) {
412 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
413 		/*
414 		 * Make sure updated value of ->s_mount_flags will be visible
415 		 * before ->s_flags update
416 		 */
417 		smp_wmb();
418 		sb->s_flags |= MS_RDONLY;
419 	}
420 	if (test_opt(sb, ERRORS_PANIC)) {
421 		if (EXT4_SB(sb)->s_journal &&
422 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
423 			return;
424 		panic("EXT4-fs (device %s): panic forced after error\n",
425 			sb->s_id);
426 	}
427 }
428 
429 #define ext4_error_ratelimit(sb)					\
430 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
431 			     "EXT4-fs error")
432 
433 void __ext4_error(struct super_block *sb, const char *function,
434 		  unsigned int line, const char *fmt, ...)
435 {
436 	struct va_format vaf;
437 	va_list args;
438 
439 	if (ext4_error_ratelimit(sb)) {
440 		va_start(args, fmt);
441 		vaf.fmt = fmt;
442 		vaf.va = &args;
443 		printk(KERN_CRIT
444 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
445 		       sb->s_id, function, line, current->comm, &vaf);
446 		va_end(args);
447 	}
448 	save_error_info(sb, function, line);
449 	ext4_handle_error(sb);
450 }
451 
452 void __ext4_error_inode(struct inode *inode, const char *function,
453 			unsigned int line, ext4_fsblk_t block,
454 			const char *fmt, ...)
455 {
456 	va_list args;
457 	struct va_format vaf;
458 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
459 
460 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
461 	es->s_last_error_block = cpu_to_le64(block);
462 	if (ext4_error_ratelimit(inode->i_sb)) {
463 		va_start(args, fmt);
464 		vaf.fmt = fmt;
465 		vaf.va = &args;
466 		if (block)
467 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
468 			       "inode #%lu: block %llu: comm %s: %pV\n",
469 			       inode->i_sb->s_id, function, line, inode->i_ino,
470 			       block, current->comm, &vaf);
471 		else
472 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
473 			       "inode #%lu: comm %s: %pV\n",
474 			       inode->i_sb->s_id, function, line, inode->i_ino,
475 			       current->comm, &vaf);
476 		va_end(args);
477 	}
478 	save_error_info(inode->i_sb, function, line);
479 	ext4_handle_error(inode->i_sb);
480 }
481 
482 void __ext4_error_file(struct file *file, const char *function,
483 		       unsigned int line, ext4_fsblk_t block,
484 		       const char *fmt, ...)
485 {
486 	va_list args;
487 	struct va_format vaf;
488 	struct ext4_super_block *es;
489 	struct inode *inode = file_inode(file);
490 	char pathname[80], *path;
491 
492 	es = EXT4_SB(inode->i_sb)->s_es;
493 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
494 	if (ext4_error_ratelimit(inode->i_sb)) {
495 		path = file_path(file, pathname, sizeof(pathname));
496 		if (IS_ERR(path))
497 			path = "(unknown)";
498 		va_start(args, fmt);
499 		vaf.fmt = fmt;
500 		vaf.va = &args;
501 		if (block)
502 			printk(KERN_CRIT
503 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
504 			       "block %llu: comm %s: path %s: %pV\n",
505 			       inode->i_sb->s_id, function, line, inode->i_ino,
506 			       block, current->comm, path, &vaf);
507 		else
508 			printk(KERN_CRIT
509 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
510 			       "comm %s: path %s: %pV\n",
511 			       inode->i_sb->s_id, function, line, inode->i_ino,
512 			       current->comm, path, &vaf);
513 		va_end(args);
514 	}
515 	save_error_info(inode->i_sb, function, line);
516 	ext4_handle_error(inode->i_sb);
517 }
518 
519 const char *ext4_decode_error(struct super_block *sb, int errno,
520 			      char nbuf[16])
521 {
522 	char *errstr = NULL;
523 
524 	switch (errno) {
525 	case -EFSCORRUPTED:
526 		errstr = "Corrupt filesystem";
527 		break;
528 	case -EFSBADCRC:
529 		errstr = "Filesystem failed CRC";
530 		break;
531 	case -EIO:
532 		errstr = "IO failure";
533 		break;
534 	case -ENOMEM:
535 		errstr = "Out of memory";
536 		break;
537 	case -EROFS:
538 		if (!sb || (EXT4_SB(sb)->s_journal &&
539 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
540 			errstr = "Journal has aborted";
541 		else
542 			errstr = "Readonly filesystem";
543 		break;
544 	default:
545 		/* If the caller passed in an extra buffer for unknown
546 		 * errors, textualise them now.  Else we just return
547 		 * NULL. */
548 		if (nbuf) {
549 			/* Check for truncated error codes... */
550 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
551 				errstr = nbuf;
552 		}
553 		break;
554 	}
555 
556 	return errstr;
557 }
558 
559 /* __ext4_std_error decodes expected errors from journaling functions
560  * automatically and invokes the appropriate error response.  */
561 
562 void __ext4_std_error(struct super_block *sb, const char *function,
563 		      unsigned int line, int errno)
564 {
565 	char nbuf[16];
566 	const char *errstr;
567 
568 	/* Special case: if the error is EROFS, and we're not already
569 	 * inside a transaction, then there's really no point in logging
570 	 * an error. */
571 	if (errno == -EROFS && journal_current_handle() == NULL &&
572 	    (sb->s_flags & MS_RDONLY))
573 		return;
574 
575 	if (ext4_error_ratelimit(sb)) {
576 		errstr = ext4_decode_error(sb, errno, nbuf);
577 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
578 		       sb->s_id, function, line, errstr);
579 	}
580 
581 	save_error_info(sb, function, line);
582 	ext4_handle_error(sb);
583 }
584 
585 /*
586  * ext4_abort is a much stronger failure handler than ext4_error.  The
587  * abort function may be used to deal with unrecoverable failures such
588  * as journal IO errors or ENOMEM at a critical moment in log management.
589  *
590  * We unconditionally force the filesystem into an ABORT|READONLY state,
591  * unless the error response on the fs has been set to panic in which
592  * case we take the easy way out and panic immediately.
593  */
594 
595 void __ext4_abort(struct super_block *sb, const char *function,
596 		unsigned int line, const char *fmt, ...)
597 {
598 	va_list args;
599 
600 	save_error_info(sb, function, line);
601 	va_start(args, fmt);
602 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
603 	       function, line);
604 	vprintk(fmt, args);
605 	printk("\n");
606 	va_end(args);
607 
608 	if ((sb->s_flags & MS_RDONLY) == 0) {
609 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
610 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
611 		/*
612 		 * Make sure updated value of ->s_mount_flags will be visible
613 		 * before ->s_flags update
614 		 */
615 		smp_wmb();
616 		sb->s_flags |= MS_RDONLY;
617 		if (EXT4_SB(sb)->s_journal)
618 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
619 		save_error_info(sb, function, line);
620 	}
621 	if (test_opt(sb, ERRORS_PANIC)) {
622 		if (EXT4_SB(sb)->s_journal &&
623 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
624 			return;
625 		panic("EXT4-fs panic from previous error\n");
626 	}
627 }
628 
629 void __ext4_msg(struct super_block *sb,
630 		const char *prefix, const char *fmt, ...)
631 {
632 	struct va_format vaf;
633 	va_list args;
634 
635 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
636 		return;
637 
638 	va_start(args, fmt);
639 	vaf.fmt = fmt;
640 	vaf.va = &args;
641 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
642 	va_end(args);
643 }
644 
645 #define ext4_warning_ratelimit(sb)					\
646 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
647 			     "EXT4-fs warning")
648 
649 void __ext4_warning(struct super_block *sb, const char *function,
650 		    unsigned int line, const char *fmt, ...)
651 {
652 	struct va_format vaf;
653 	va_list args;
654 
655 	if (!ext4_warning_ratelimit(sb))
656 		return;
657 
658 	va_start(args, fmt);
659 	vaf.fmt = fmt;
660 	vaf.va = &args;
661 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
662 	       sb->s_id, function, line, &vaf);
663 	va_end(args);
664 }
665 
666 void __ext4_warning_inode(const struct inode *inode, const char *function,
667 			  unsigned int line, const char *fmt, ...)
668 {
669 	struct va_format vaf;
670 	va_list args;
671 
672 	if (!ext4_warning_ratelimit(inode->i_sb))
673 		return;
674 
675 	va_start(args, fmt);
676 	vaf.fmt = fmt;
677 	vaf.va = &args;
678 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
679 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
680 	       function, line, inode->i_ino, current->comm, &vaf);
681 	va_end(args);
682 }
683 
684 void __ext4_grp_locked_error(const char *function, unsigned int line,
685 			     struct super_block *sb, ext4_group_t grp,
686 			     unsigned long ino, ext4_fsblk_t block,
687 			     const char *fmt, ...)
688 __releases(bitlock)
689 __acquires(bitlock)
690 {
691 	struct va_format vaf;
692 	va_list args;
693 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
694 
695 	es->s_last_error_ino = cpu_to_le32(ino);
696 	es->s_last_error_block = cpu_to_le64(block);
697 	__save_error_info(sb, function, line);
698 
699 	if (ext4_error_ratelimit(sb)) {
700 		va_start(args, fmt);
701 		vaf.fmt = fmt;
702 		vaf.va = &args;
703 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
704 		       sb->s_id, function, line, grp);
705 		if (ino)
706 			printk(KERN_CONT "inode %lu: ", ino);
707 		if (block)
708 			printk(KERN_CONT "block %llu:",
709 			       (unsigned long long) block);
710 		printk(KERN_CONT "%pV\n", &vaf);
711 		va_end(args);
712 	}
713 
714 	if (test_opt(sb, ERRORS_CONT)) {
715 		ext4_commit_super(sb, 0);
716 		return;
717 	}
718 
719 	ext4_unlock_group(sb, grp);
720 	ext4_handle_error(sb);
721 	/*
722 	 * We only get here in the ERRORS_RO case; relocking the group
723 	 * may be dangerous, but nothing bad will happen since the
724 	 * filesystem will have already been marked read/only and the
725 	 * journal has been aborted.  We return 1 as a hint to callers
726 	 * who might what to use the return value from
727 	 * ext4_grp_locked_error() to distinguish between the
728 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
729 	 * aggressively from the ext4 function in question, with a
730 	 * more appropriate error code.
731 	 */
732 	ext4_lock_group(sb, grp);
733 	return;
734 }
735 
736 void ext4_update_dynamic_rev(struct super_block *sb)
737 {
738 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
739 
740 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
741 		return;
742 
743 	ext4_warning(sb,
744 		     "updating to rev %d because of new feature flag, "
745 		     "running e2fsck is recommended",
746 		     EXT4_DYNAMIC_REV);
747 
748 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
749 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
750 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
751 	/* leave es->s_feature_*compat flags alone */
752 	/* es->s_uuid will be set by e2fsck if empty */
753 
754 	/*
755 	 * The rest of the superblock fields should be zero, and if not it
756 	 * means they are likely already in use, so leave them alone.  We
757 	 * can leave it up to e2fsck to clean up any inconsistencies there.
758 	 */
759 }
760 
761 /*
762  * Open the external journal device
763  */
764 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
765 {
766 	struct block_device *bdev;
767 	char b[BDEVNAME_SIZE];
768 
769 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
770 	if (IS_ERR(bdev))
771 		goto fail;
772 	return bdev;
773 
774 fail:
775 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
776 			__bdevname(dev, b), PTR_ERR(bdev));
777 	return NULL;
778 }
779 
780 /*
781  * Release the journal device
782  */
783 static void ext4_blkdev_put(struct block_device *bdev)
784 {
785 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
786 }
787 
788 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
789 {
790 	struct block_device *bdev;
791 	bdev = sbi->journal_bdev;
792 	if (bdev) {
793 		ext4_blkdev_put(bdev);
794 		sbi->journal_bdev = NULL;
795 	}
796 }
797 
798 static inline struct inode *orphan_list_entry(struct list_head *l)
799 {
800 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
801 }
802 
803 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
804 {
805 	struct list_head *l;
806 
807 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
808 		 le32_to_cpu(sbi->s_es->s_last_orphan));
809 
810 	printk(KERN_ERR "sb_info orphan list:\n");
811 	list_for_each(l, &sbi->s_orphan) {
812 		struct inode *inode = orphan_list_entry(l);
813 		printk(KERN_ERR "  "
814 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
815 		       inode->i_sb->s_id, inode->i_ino, inode,
816 		       inode->i_mode, inode->i_nlink,
817 		       NEXT_ORPHAN(inode));
818 	}
819 }
820 
821 static void ext4_put_super(struct super_block *sb)
822 {
823 	struct ext4_sb_info *sbi = EXT4_SB(sb);
824 	struct ext4_super_block *es = sbi->s_es;
825 	int i, err;
826 
827 	ext4_unregister_li_request(sb);
828 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
829 
830 	flush_workqueue(sbi->rsv_conversion_wq);
831 	destroy_workqueue(sbi->rsv_conversion_wq);
832 
833 	if (sbi->s_journal) {
834 		err = jbd2_journal_destroy(sbi->s_journal);
835 		sbi->s_journal = NULL;
836 		if (err < 0)
837 			ext4_abort(sb, "Couldn't clean up the journal");
838 	}
839 
840 	ext4_unregister_sysfs(sb);
841 	ext4_es_unregister_shrinker(sbi);
842 	del_timer_sync(&sbi->s_err_report);
843 	ext4_release_system_zone(sb);
844 	ext4_mb_release(sb);
845 	ext4_ext_release(sb);
846 
847 	if (!(sb->s_flags & MS_RDONLY)) {
848 		ext4_clear_feature_journal_needs_recovery(sb);
849 		es->s_state = cpu_to_le16(sbi->s_mount_state);
850 	}
851 	if (!(sb->s_flags & MS_RDONLY))
852 		ext4_commit_super(sb, 1);
853 
854 	for (i = 0; i < sbi->s_gdb_count; i++)
855 		brelse(sbi->s_group_desc[i]);
856 	kvfree(sbi->s_group_desc);
857 	kvfree(sbi->s_flex_groups);
858 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
859 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
860 	percpu_counter_destroy(&sbi->s_dirs_counter);
861 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
862 	brelse(sbi->s_sbh);
863 #ifdef CONFIG_QUOTA
864 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
865 		kfree(sbi->s_qf_names[i]);
866 #endif
867 
868 	/* Debugging code just in case the in-memory inode orphan list
869 	 * isn't empty.  The on-disk one can be non-empty if we've
870 	 * detected an error and taken the fs readonly, but the
871 	 * in-memory list had better be clean by this point. */
872 	if (!list_empty(&sbi->s_orphan))
873 		dump_orphan_list(sb, sbi);
874 	J_ASSERT(list_empty(&sbi->s_orphan));
875 
876 	sync_blockdev(sb->s_bdev);
877 	invalidate_bdev(sb->s_bdev);
878 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
879 		/*
880 		 * Invalidate the journal device's buffers.  We don't want them
881 		 * floating about in memory - the physical journal device may
882 		 * hotswapped, and it breaks the `ro-after' testing code.
883 		 */
884 		sync_blockdev(sbi->journal_bdev);
885 		invalidate_bdev(sbi->journal_bdev);
886 		ext4_blkdev_remove(sbi);
887 	}
888 	if (sbi->s_mb_cache) {
889 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
890 		sbi->s_mb_cache = NULL;
891 	}
892 	if (sbi->s_mmp_tsk)
893 		kthread_stop(sbi->s_mmp_tsk);
894 	sb->s_fs_info = NULL;
895 	/*
896 	 * Now that we are completely done shutting down the
897 	 * superblock, we need to actually destroy the kobject.
898 	 */
899 	kobject_put(&sbi->s_kobj);
900 	wait_for_completion(&sbi->s_kobj_unregister);
901 	if (sbi->s_chksum_driver)
902 		crypto_free_shash(sbi->s_chksum_driver);
903 	kfree(sbi->s_blockgroup_lock);
904 	kfree(sbi);
905 }
906 
907 static struct kmem_cache *ext4_inode_cachep;
908 
909 /*
910  * Called inside transaction, so use GFP_NOFS
911  */
912 static struct inode *ext4_alloc_inode(struct super_block *sb)
913 {
914 	struct ext4_inode_info *ei;
915 
916 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
917 	if (!ei)
918 		return NULL;
919 
920 	ei->vfs_inode.i_version = 1;
921 	spin_lock_init(&ei->i_raw_lock);
922 	INIT_LIST_HEAD(&ei->i_prealloc_list);
923 	spin_lock_init(&ei->i_prealloc_lock);
924 	ext4_es_init_tree(&ei->i_es_tree);
925 	rwlock_init(&ei->i_es_lock);
926 	INIT_LIST_HEAD(&ei->i_es_list);
927 	ei->i_es_all_nr = 0;
928 	ei->i_es_shk_nr = 0;
929 	ei->i_es_shrink_lblk = 0;
930 	ei->i_reserved_data_blocks = 0;
931 	ei->i_reserved_meta_blocks = 0;
932 	ei->i_allocated_meta_blocks = 0;
933 	ei->i_da_metadata_calc_len = 0;
934 	ei->i_da_metadata_calc_last_lblock = 0;
935 	spin_lock_init(&(ei->i_block_reservation_lock));
936 #ifdef CONFIG_QUOTA
937 	ei->i_reserved_quota = 0;
938 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
939 #endif
940 	ei->jinode = NULL;
941 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
942 	spin_lock_init(&ei->i_completed_io_lock);
943 	ei->i_sync_tid = 0;
944 	ei->i_datasync_tid = 0;
945 	atomic_set(&ei->i_unwritten, 0);
946 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
947 #ifdef CONFIG_EXT4_FS_ENCRYPTION
948 	ei->i_crypt_info = NULL;
949 #endif
950 	return &ei->vfs_inode;
951 }
952 
953 static int ext4_drop_inode(struct inode *inode)
954 {
955 	int drop = generic_drop_inode(inode);
956 
957 	trace_ext4_drop_inode(inode, drop);
958 	return drop;
959 }
960 
961 static void ext4_i_callback(struct rcu_head *head)
962 {
963 	struct inode *inode = container_of(head, struct inode, i_rcu);
964 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
965 }
966 
967 static void ext4_destroy_inode(struct inode *inode)
968 {
969 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
970 		ext4_msg(inode->i_sb, KERN_ERR,
971 			 "Inode %lu (%p): orphan list check failed!",
972 			 inode->i_ino, EXT4_I(inode));
973 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
974 				EXT4_I(inode), sizeof(struct ext4_inode_info),
975 				true);
976 		dump_stack();
977 	}
978 	call_rcu(&inode->i_rcu, ext4_i_callback);
979 }
980 
981 static void init_once(void *foo)
982 {
983 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
984 
985 	INIT_LIST_HEAD(&ei->i_orphan);
986 	init_rwsem(&ei->xattr_sem);
987 	init_rwsem(&ei->i_data_sem);
988 	init_rwsem(&ei->i_mmap_sem);
989 	inode_init_once(&ei->vfs_inode);
990 }
991 
992 static int __init init_inodecache(void)
993 {
994 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
995 					     sizeof(struct ext4_inode_info),
996 					     0, (SLAB_RECLAIM_ACCOUNT|
997 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
998 					     init_once);
999 	if (ext4_inode_cachep == NULL)
1000 		return -ENOMEM;
1001 	return 0;
1002 }
1003 
1004 static void destroy_inodecache(void)
1005 {
1006 	/*
1007 	 * Make sure all delayed rcu free inodes are flushed before we
1008 	 * destroy cache.
1009 	 */
1010 	rcu_barrier();
1011 	kmem_cache_destroy(ext4_inode_cachep);
1012 }
1013 
1014 void ext4_clear_inode(struct inode *inode)
1015 {
1016 	invalidate_inode_buffers(inode);
1017 	clear_inode(inode);
1018 	dquot_drop(inode);
1019 	ext4_discard_preallocations(inode);
1020 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1021 	if (EXT4_I(inode)->jinode) {
1022 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1023 					       EXT4_I(inode)->jinode);
1024 		jbd2_free_inode(EXT4_I(inode)->jinode);
1025 		EXT4_I(inode)->jinode = NULL;
1026 	}
1027 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1028 	if (EXT4_I(inode)->i_crypt_info)
1029 		ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info);
1030 #endif
1031 }
1032 
1033 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1034 					u64 ino, u32 generation)
1035 {
1036 	struct inode *inode;
1037 
1038 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1039 		return ERR_PTR(-ESTALE);
1040 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1041 		return ERR_PTR(-ESTALE);
1042 
1043 	/* iget isn't really right if the inode is currently unallocated!!
1044 	 *
1045 	 * ext4_read_inode will return a bad_inode if the inode had been
1046 	 * deleted, so we should be safe.
1047 	 *
1048 	 * Currently we don't know the generation for parent directory, so
1049 	 * a generation of 0 means "accept any"
1050 	 */
1051 	inode = ext4_iget_normal(sb, ino);
1052 	if (IS_ERR(inode))
1053 		return ERR_CAST(inode);
1054 	if (generation && inode->i_generation != generation) {
1055 		iput(inode);
1056 		return ERR_PTR(-ESTALE);
1057 	}
1058 
1059 	return inode;
1060 }
1061 
1062 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1063 					int fh_len, int fh_type)
1064 {
1065 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1066 				    ext4_nfs_get_inode);
1067 }
1068 
1069 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1070 					int fh_len, int fh_type)
1071 {
1072 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1073 				    ext4_nfs_get_inode);
1074 }
1075 
1076 /*
1077  * Try to release metadata pages (indirect blocks, directories) which are
1078  * mapped via the block device.  Since these pages could have journal heads
1079  * which would prevent try_to_free_buffers() from freeing them, we must use
1080  * jbd2 layer's try_to_free_buffers() function to release them.
1081  */
1082 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1083 				 gfp_t wait)
1084 {
1085 	journal_t *journal = EXT4_SB(sb)->s_journal;
1086 
1087 	WARN_ON(PageChecked(page));
1088 	if (!page_has_buffers(page))
1089 		return 0;
1090 	if (journal)
1091 		return jbd2_journal_try_to_free_buffers(journal, page,
1092 						wait & ~__GFP_DIRECT_RECLAIM);
1093 	return try_to_free_buffers(page);
1094 }
1095 
1096 #ifdef CONFIG_QUOTA
1097 static char *quotatypes[] = INITQFNAMES;
1098 #define QTYPE2NAME(t) (quotatypes[t])
1099 
1100 static int ext4_write_dquot(struct dquot *dquot);
1101 static int ext4_acquire_dquot(struct dquot *dquot);
1102 static int ext4_release_dquot(struct dquot *dquot);
1103 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1104 static int ext4_write_info(struct super_block *sb, int type);
1105 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1106 			 struct path *path);
1107 static int ext4_quota_off(struct super_block *sb, int type);
1108 static int ext4_quota_on_mount(struct super_block *sb, int type);
1109 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1110 			       size_t len, loff_t off);
1111 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1112 				const char *data, size_t len, loff_t off);
1113 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1114 			     unsigned int flags);
1115 static int ext4_enable_quotas(struct super_block *sb);
1116 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1117 
1118 static struct dquot **ext4_get_dquots(struct inode *inode)
1119 {
1120 	return EXT4_I(inode)->i_dquot;
1121 }
1122 
1123 static const struct dquot_operations ext4_quota_operations = {
1124 	.get_reserved_space = ext4_get_reserved_space,
1125 	.write_dquot	= ext4_write_dquot,
1126 	.acquire_dquot	= ext4_acquire_dquot,
1127 	.release_dquot	= ext4_release_dquot,
1128 	.mark_dirty	= ext4_mark_dquot_dirty,
1129 	.write_info	= ext4_write_info,
1130 	.alloc_dquot	= dquot_alloc,
1131 	.destroy_dquot	= dquot_destroy,
1132 	.get_projid	= ext4_get_projid,
1133 	.get_next_id	= ext4_get_next_id,
1134 };
1135 
1136 static const struct quotactl_ops ext4_qctl_operations = {
1137 	.quota_on	= ext4_quota_on,
1138 	.quota_off	= ext4_quota_off,
1139 	.quota_sync	= dquot_quota_sync,
1140 	.get_state	= dquot_get_state,
1141 	.set_info	= dquot_set_dqinfo,
1142 	.get_dqblk	= dquot_get_dqblk,
1143 	.set_dqblk	= dquot_set_dqblk,
1144 	.get_nextdqblk	= dquot_get_next_dqblk,
1145 };
1146 #endif
1147 
1148 static const struct super_operations ext4_sops = {
1149 	.alloc_inode	= ext4_alloc_inode,
1150 	.destroy_inode	= ext4_destroy_inode,
1151 	.write_inode	= ext4_write_inode,
1152 	.dirty_inode	= ext4_dirty_inode,
1153 	.drop_inode	= ext4_drop_inode,
1154 	.evict_inode	= ext4_evict_inode,
1155 	.put_super	= ext4_put_super,
1156 	.sync_fs	= ext4_sync_fs,
1157 	.freeze_fs	= ext4_freeze,
1158 	.unfreeze_fs	= ext4_unfreeze,
1159 	.statfs		= ext4_statfs,
1160 	.remount_fs	= ext4_remount,
1161 	.show_options	= ext4_show_options,
1162 #ifdef CONFIG_QUOTA
1163 	.quota_read	= ext4_quota_read,
1164 	.quota_write	= ext4_quota_write,
1165 	.get_dquots	= ext4_get_dquots,
1166 #endif
1167 	.bdev_try_to_free_page = bdev_try_to_free_page,
1168 };
1169 
1170 static const struct export_operations ext4_export_ops = {
1171 	.fh_to_dentry = ext4_fh_to_dentry,
1172 	.fh_to_parent = ext4_fh_to_parent,
1173 	.get_parent = ext4_get_parent,
1174 };
1175 
1176 enum {
1177 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1178 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1179 	Opt_nouid32, Opt_debug, Opt_removed,
1180 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1181 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1182 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1183 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1184 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1185 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1186 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1187 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1188 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1189 	Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1190 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1191 	Opt_lazytime, Opt_nolazytime,
1192 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1193 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1194 	Opt_dioread_nolock, Opt_dioread_lock,
1195 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1196 	Opt_max_dir_size_kb, Opt_nojournal_checksum,
1197 };
1198 
1199 static const match_table_t tokens = {
1200 	{Opt_bsd_df, "bsddf"},
1201 	{Opt_minix_df, "minixdf"},
1202 	{Opt_grpid, "grpid"},
1203 	{Opt_grpid, "bsdgroups"},
1204 	{Opt_nogrpid, "nogrpid"},
1205 	{Opt_nogrpid, "sysvgroups"},
1206 	{Opt_resgid, "resgid=%u"},
1207 	{Opt_resuid, "resuid=%u"},
1208 	{Opt_sb, "sb=%u"},
1209 	{Opt_err_cont, "errors=continue"},
1210 	{Opt_err_panic, "errors=panic"},
1211 	{Opt_err_ro, "errors=remount-ro"},
1212 	{Opt_nouid32, "nouid32"},
1213 	{Opt_debug, "debug"},
1214 	{Opt_removed, "oldalloc"},
1215 	{Opt_removed, "orlov"},
1216 	{Opt_user_xattr, "user_xattr"},
1217 	{Opt_nouser_xattr, "nouser_xattr"},
1218 	{Opt_acl, "acl"},
1219 	{Opt_noacl, "noacl"},
1220 	{Opt_noload, "norecovery"},
1221 	{Opt_noload, "noload"},
1222 	{Opt_removed, "nobh"},
1223 	{Opt_removed, "bh"},
1224 	{Opt_commit, "commit=%u"},
1225 	{Opt_min_batch_time, "min_batch_time=%u"},
1226 	{Opt_max_batch_time, "max_batch_time=%u"},
1227 	{Opt_journal_dev, "journal_dev=%u"},
1228 	{Opt_journal_path, "journal_path=%s"},
1229 	{Opt_journal_checksum, "journal_checksum"},
1230 	{Opt_nojournal_checksum, "nojournal_checksum"},
1231 	{Opt_journal_async_commit, "journal_async_commit"},
1232 	{Opt_abort, "abort"},
1233 	{Opt_data_journal, "data=journal"},
1234 	{Opt_data_ordered, "data=ordered"},
1235 	{Opt_data_writeback, "data=writeback"},
1236 	{Opt_data_err_abort, "data_err=abort"},
1237 	{Opt_data_err_ignore, "data_err=ignore"},
1238 	{Opt_offusrjquota, "usrjquota="},
1239 	{Opt_usrjquota, "usrjquota=%s"},
1240 	{Opt_offgrpjquota, "grpjquota="},
1241 	{Opt_grpjquota, "grpjquota=%s"},
1242 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1243 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1244 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1245 	{Opt_grpquota, "grpquota"},
1246 	{Opt_noquota, "noquota"},
1247 	{Opt_quota, "quota"},
1248 	{Opt_usrquota, "usrquota"},
1249 	{Opt_barrier, "barrier=%u"},
1250 	{Opt_barrier, "barrier"},
1251 	{Opt_nobarrier, "nobarrier"},
1252 	{Opt_i_version, "i_version"},
1253 	{Opt_dax, "dax"},
1254 	{Opt_stripe, "stripe=%u"},
1255 	{Opt_delalloc, "delalloc"},
1256 	{Opt_lazytime, "lazytime"},
1257 	{Opt_nolazytime, "nolazytime"},
1258 	{Opt_nodelalloc, "nodelalloc"},
1259 	{Opt_removed, "mblk_io_submit"},
1260 	{Opt_removed, "nomblk_io_submit"},
1261 	{Opt_block_validity, "block_validity"},
1262 	{Opt_noblock_validity, "noblock_validity"},
1263 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1264 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1265 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1266 	{Opt_auto_da_alloc, "auto_da_alloc"},
1267 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1268 	{Opt_dioread_nolock, "dioread_nolock"},
1269 	{Opt_dioread_lock, "dioread_lock"},
1270 	{Opt_discard, "discard"},
1271 	{Opt_nodiscard, "nodiscard"},
1272 	{Opt_init_itable, "init_itable=%u"},
1273 	{Opt_init_itable, "init_itable"},
1274 	{Opt_noinit_itable, "noinit_itable"},
1275 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1276 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1277 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1278 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1279 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1280 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1281 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1282 	{Opt_err, NULL},
1283 };
1284 
1285 static ext4_fsblk_t get_sb_block(void **data)
1286 {
1287 	ext4_fsblk_t	sb_block;
1288 	char		*options = (char *) *data;
1289 
1290 	if (!options || strncmp(options, "sb=", 3) != 0)
1291 		return 1;	/* Default location */
1292 
1293 	options += 3;
1294 	/* TODO: use simple_strtoll with >32bit ext4 */
1295 	sb_block = simple_strtoul(options, &options, 0);
1296 	if (*options && *options != ',') {
1297 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1298 		       (char *) *data);
1299 		return 1;
1300 	}
1301 	if (*options == ',')
1302 		options++;
1303 	*data = (void *) options;
1304 
1305 	return sb_block;
1306 }
1307 
1308 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1309 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1310 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1311 
1312 #ifdef CONFIG_QUOTA
1313 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1314 {
1315 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1316 	char *qname;
1317 	int ret = -1;
1318 
1319 	if (sb_any_quota_loaded(sb) &&
1320 		!sbi->s_qf_names[qtype]) {
1321 		ext4_msg(sb, KERN_ERR,
1322 			"Cannot change journaled "
1323 			"quota options when quota turned on");
1324 		return -1;
1325 	}
1326 	if (ext4_has_feature_quota(sb)) {
1327 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1328 			 "ignored when QUOTA feature is enabled");
1329 		return 1;
1330 	}
1331 	qname = match_strdup(args);
1332 	if (!qname) {
1333 		ext4_msg(sb, KERN_ERR,
1334 			"Not enough memory for storing quotafile name");
1335 		return -1;
1336 	}
1337 	if (sbi->s_qf_names[qtype]) {
1338 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1339 			ret = 1;
1340 		else
1341 			ext4_msg(sb, KERN_ERR,
1342 				 "%s quota file already specified",
1343 				 QTYPE2NAME(qtype));
1344 		goto errout;
1345 	}
1346 	if (strchr(qname, '/')) {
1347 		ext4_msg(sb, KERN_ERR,
1348 			"quotafile must be on filesystem root");
1349 		goto errout;
1350 	}
1351 	sbi->s_qf_names[qtype] = qname;
1352 	set_opt(sb, QUOTA);
1353 	return 1;
1354 errout:
1355 	kfree(qname);
1356 	return ret;
1357 }
1358 
1359 static int clear_qf_name(struct super_block *sb, int qtype)
1360 {
1361 
1362 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1363 
1364 	if (sb_any_quota_loaded(sb) &&
1365 		sbi->s_qf_names[qtype]) {
1366 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1367 			" when quota turned on");
1368 		return -1;
1369 	}
1370 	kfree(sbi->s_qf_names[qtype]);
1371 	sbi->s_qf_names[qtype] = NULL;
1372 	return 1;
1373 }
1374 #endif
1375 
1376 #define MOPT_SET	0x0001
1377 #define MOPT_CLEAR	0x0002
1378 #define MOPT_NOSUPPORT	0x0004
1379 #define MOPT_EXPLICIT	0x0008
1380 #define MOPT_CLEAR_ERR	0x0010
1381 #define MOPT_GTE0	0x0020
1382 #ifdef CONFIG_QUOTA
1383 #define MOPT_Q		0
1384 #define MOPT_QFMT	0x0040
1385 #else
1386 #define MOPT_Q		MOPT_NOSUPPORT
1387 #define MOPT_QFMT	MOPT_NOSUPPORT
1388 #endif
1389 #define MOPT_DATAJ	0x0080
1390 #define MOPT_NO_EXT2	0x0100
1391 #define MOPT_NO_EXT3	0x0200
1392 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1393 #define MOPT_STRING	0x0400
1394 
1395 static const struct mount_opts {
1396 	int	token;
1397 	int	mount_opt;
1398 	int	flags;
1399 } ext4_mount_opts[] = {
1400 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1401 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1402 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1403 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1404 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1405 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1406 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1407 	 MOPT_EXT4_ONLY | MOPT_SET},
1408 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1409 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1410 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1411 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1412 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1413 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1414 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1415 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1416 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1417 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1418 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1419 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1420 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1421 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1422 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1423 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1424 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1425 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1426 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1427 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1428 	 MOPT_NO_EXT2},
1429 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1430 	 MOPT_NO_EXT2},
1431 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1432 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1433 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1434 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1435 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1436 	{Opt_commit, 0, MOPT_GTE0},
1437 	{Opt_max_batch_time, 0, MOPT_GTE0},
1438 	{Opt_min_batch_time, 0, MOPT_GTE0},
1439 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1440 	{Opt_init_itable, 0, MOPT_GTE0},
1441 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1442 	{Opt_stripe, 0, MOPT_GTE0},
1443 	{Opt_resuid, 0, MOPT_GTE0},
1444 	{Opt_resgid, 0, MOPT_GTE0},
1445 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1446 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1447 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1448 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1449 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1450 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1451 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1452 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1453 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1454 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1455 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1456 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1457 #else
1458 	{Opt_acl, 0, MOPT_NOSUPPORT},
1459 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1460 #endif
1461 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1462 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1463 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1464 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1465 							MOPT_SET | MOPT_Q},
1466 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1467 							MOPT_SET | MOPT_Q},
1468 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1469 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1470 	{Opt_usrjquota, 0, MOPT_Q},
1471 	{Opt_grpjquota, 0, MOPT_Q},
1472 	{Opt_offusrjquota, 0, MOPT_Q},
1473 	{Opt_offgrpjquota, 0, MOPT_Q},
1474 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1475 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1476 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1477 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1478 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1479 	{Opt_err, 0, 0}
1480 };
1481 
1482 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1483 			    substring_t *args, unsigned long *journal_devnum,
1484 			    unsigned int *journal_ioprio, int is_remount)
1485 {
1486 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1487 	const struct mount_opts *m;
1488 	kuid_t uid;
1489 	kgid_t gid;
1490 	int arg = 0;
1491 
1492 #ifdef CONFIG_QUOTA
1493 	if (token == Opt_usrjquota)
1494 		return set_qf_name(sb, USRQUOTA, &args[0]);
1495 	else if (token == Opt_grpjquota)
1496 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1497 	else if (token == Opt_offusrjquota)
1498 		return clear_qf_name(sb, USRQUOTA);
1499 	else if (token == Opt_offgrpjquota)
1500 		return clear_qf_name(sb, GRPQUOTA);
1501 #endif
1502 	switch (token) {
1503 	case Opt_noacl:
1504 	case Opt_nouser_xattr:
1505 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1506 		break;
1507 	case Opt_sb:
1508 		return 1;	/* handled by get_sb_block() */
1509 	case Opt_removed:
1510 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1511 		return 1;
1512 	case Opt_abort:
1513 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1514 		return 1;
1515 	case Opt_i_version:
1516 		sb->s_flags |= MS_I_VERSION;
1517 		return 1;
1518 	case Opt_lazytime:
1519 		sb->s_flags |= MS_LAZYTIME;
1520 		return 1;
1521 	case Opt_nolazytime:
1522 		sb->s_flags &= ~MS_LAZYTIME;
1523 		return 1;
1524 	}
1525 
1526 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1527 		if (token == m->token)
1528 			break;
1529 
1530 	if (m->token == Opt_err) {
1531 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1532 			 "or missing value", opt);
1533 		return -1;
1534 	}
1535 
1536 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1537 		ext4_msg(sb, KERN_ERR,
1538 			 "Mount option \"%s\" incompatible with ext2", opt);
1539 		return -1;
1540 	}
1541 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1542 		ext4_msg(sb, KERN_ERR,
1543 			 "Mount option \"%s\" incompatible with ext3", opt);
1544 		return -1;
1545 	}
1546 
1547 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1548 		return -1;
1549 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1550 		return -1;
1551 	if (m->flags & MOPT_EXPLICIT) {
1552 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1553 			set_opt2(sb, EXPLICIT_DELALLOC);
1554 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1555 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1556 		} else
1557 			return -1;
1558 	}
1559 	if (m->flags & MOPT_CLEAR_ERR)
1560 		clear_opt(sb, ERRORS_MASK);
1561 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1562 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1563 			 "options when quota turned on");
1564 		return -1;
1565 	}
1566 
1567 	if (m->flags & MOPT_NOSUPPORT) {
1568 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1569 	} else if (token == Opt_commit) {
1570 		if (arg == 0)
1571 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1572 		sbi->s_commit_interval = HZ * arg;
1573 	} else if (token == Opt_max_batch_time) {
1574 		sbi->s_max_batch_time = arg;
1575 	} else if (token == Opt_min_batch_time) {
1576 		sbi->s_min_batch_time = arg;
1577 	} else if (token == Opt_inode_readahead_blks) {
1578 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1579 			ext4_msg(sb, KERN_ERR,
1580 				 "EXT4-fs: inode_readahead_blks must be "
1581 				 "0 or a power of 2 smaller than 2^31");
1582 			return -1;
1583 		}
1584 		sbi->s_inode_readahead_blks = arg;
1585 	} else if (token == Opt_init_itable) {
1586 		set_opt(sb, INIT_INODE_TABLE);
1587 		if (!args->from)
1588 			arg = EXT4_DEF_LI_WAIT_MULT;
1589 		sbi->s_li_wait_mult = arg;
1590 	} else if (token == Opt_max_dir_size_kb) {
1591 		sbi->s_max_dir_size_kb = arg;
1592 	} else if (token == Opt_stripe) {
1593 		sbi->s_stripe = arg;
1594 	} else if (token == Opt_resuid) {
1595 		uid = make_kuid(current_user_ns(), arg);
1596 		if (!uid_valid(uid)) {
1597 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1598 			return -1;
1599 		}
1600 		sbi->s_resuid = uid;
1601 	} else if (token == Opt_resgid) {
1602 		gid = make_kgid(current_user_ns(), arg);
1603 		if (!gid_valid(gid)) {
1604 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1605 			return -1;
1606 		}
1607 		sbi->s_resgid = gid;
1608 	} else if (token == Opt_journal_dev) {
1609 		if (is_remount) {
1610 			ext4_msg(sb, KERN_ERR,
1611 				 "Cannot specify journal on remount");
1612 			return -1;
1613 		}
1614 		*journal_devnum = arg;
1615 	} else if (token == Opt_journal_path) {
1616 		char *journal_path;
1617 		struct inode *journal_inode;
1618 		struct path path;
1619 		int error;
1620 
1621 		if (is_remount) {
1622 			ext4_msg(sb, KERN_ERR,
1623 				 "Cannot specify journal on remount");
1624 			return -1;
1625 		}
1626 		journal_path = match_strdup(&args[0]);
1627 		if (!journal_path) {
1628 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1629 				"journal device string");
1630 			return -1;
1631 		}
1632 
1633 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1634 		if (error) {
1635 			ext4_msg(sb, KERN_ERR, "error: could not find "
1636 				"journal device path: error %d", error);
1637 			kfree(journal_path);
1638 			return -1;
1639 		}
1640 
1641 		journal_inode = d_inode(path.dentry);
1642 		if (!S_ISBLK(journal_inode->i_mode)) {
1643 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1644 				"is not a block device", journal_path);
1645 			path_put(&path);
1646 			kfree(journal_path);
1647 			return -1;
1648 		}
1649 
1650 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1651 		path_put(&path);
1652 		kfree(journal_path);
1653 	} else if (token == Opt_journal_ioprio) {
1654 		if (arg > 7) {
1655 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1656 				 " (must be 0-7)");
1657 			return -1;
1658 		}
1659 		*journal_ioprio =
1660 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1661 	} else if (token == Opt_test_dummy_encryption) {
1662 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1663 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1664 		ext4_msg(sb, KERN_WARNING,
1665 			 "Test dummy encryption mode enabled");
1666 #else
1667 		ext4_msg(sb, KERN_WARNING,
1668 			 "Test dummy encryption mount option ignored");
1669 #endif
1670 	} else if (m->flags & MOPT_DATAJ) {
1671 		if (is_remount) {
1672 			if (!sbi->s_journal)
1673 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1674 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1675 				ext4_msg(sb, KERN_ERR,
1676 					 "Cannot change data mode on remount");
1677 				return -1;
1678 			}
1679 		} else {
1680 			clear_opt(sb, DATA_FLAGS);
1681 			sbi->s_mount_opt |= m->mount_opt;
1682 		}
1683 #ifdef CONFIG_QUOTA
1684 	} else if (m->flags & MOPT_QFMT) {
1685 		if (sb_any_quota_loaded(sb) &&
1686 		    sbi->s_jquota_fmt != m->mount_opt) {
1687 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1688 				 "quota options when quota turned on");
1689 			return -1;
1690 		}
1691 		if (ext4_has_feature_quota(sb)) {
1692 			ext4_msg(sb, KERN_INFO,
1693 				 "Quota format mount options ignored "
1694 				 "when QUOTA feature is enabled");
1695 			return 1;
1696 		}
1697 		sbi->s_jquota_fmt = m->mount_opt;
1698 #endif
1699 	} else if (token == Opt_dax) {
1700 #ifdef CONFIG_FS_DAX
1701 		ext4_msg(sb, KERN_WARNING,
1702 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1703 			sbi->s_mount_opt |= m->mount_opt;
1704 #else
1705 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1706 		return -1;
1707 #endif
1708 	} else if (token == Opt_data_err_abort) {
1709 		sbi->s_mount_opt |= m->mount_opt;
1710 	} else if (token == Opt_data_err_ignore) {
1711 		sbi->s_mount_opt &= ~m->mount_opt;
1712 	} else {
1713 		if (!args->from)
1714 			arg = 1;
1715 		if (m->flags & MOPT_CLEAR)
1716 			arg = !arg;
1717 		else if (unlikely(!(m->flags & MOPT_SET))) {
1718 			ext4_msg(sb, KERN_WARNING,
1719 				 "buggy handling of option %s", opt);
1720 			WARN_ON(1);
1721 			return -1;
1722 		}
1723 		if (arg != 0)
1724 			sbi->s_mount_opt |= m->mount_opt;
1725 		else
1726 			sbi->s_mount_opt &= ~m->mount_opt;
1727 	}
1728 	return 1;
1729 }
1730 
1731 static int parse_options(char *options, struct super_block *sb,
1732 			 unsigned long *journal_devnum,
1733 			 unsigned int *journal_ioprio,
1734 			 int is_remount)
1735 {
1736 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1737 	char *p;
1738 	substring_t args[MAX_OPT_ARGS];
1739 	int token;
1740 
1741 	if (!options)
1742 		return 1;
1743 
1744 	while ((p = strsep(&options, ",")) != NULL) {
1745 		if (!*p)
1746 			continue;
1747 		/*
1748 		 * Initialize args struct so we know whether arg was
1749 		 * found; some options take optional arguments.
1750 		 */
1751 		args[0].to = args[0].from = NULL;
1752 		token = match_token(p, tokens, args);
1753 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1754 				     journal_ioprio, is_remount) < 0)
1755 			return 0;
1756 	}
1757 #ifdef CONFIG_QUOTA
1758 	if (ext4_has_feature_quota(sb) &&
1759 	    (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1760 		ext4_msg(sb, KERN_INFO, "Quota feature enabled, usrquota and grpquota "
1761 			 "mount options ignored.");
1762 		clear_opt(sb, USRQUOTA);
1763 		clear_opt(sb, GRPQUOTA);
1764 	} else if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1765 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1766 			clear_opt(sb, USRQUOTA);
1767 
1768 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1769 			clear_opt(sb, GRPQUOTA);
1770 
1771 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1772 			ext4_msg(sb, KERN_ERR, "old and new quota "
1773 					"format mixing");
1774 			return 0;
1775 		}
1776 
1777 		if (!sbi->s_jquota_fmt) {
1778 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1779 					"not specified");
1780 			return 0;
1781 		}
1782 	}
1783 #endif
1784 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1785 		int blocksize =
1786 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1787 
1788 		if (blocksize < PAGE_SIZE) {
1789 			ext4_msg(sb, KERN_ERR, "can't mount with "
1790 				 "dioread_nolock if block size != PAGE_SIZE");
1791 			return 0;
1792 		}
1793 	}
1794 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1795 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1796 		ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1797 			 "in data=ordered mode");
1798 		return 0;
1799 	}
1800 	return 1;
1801 }
1802 
1803 static inline void ext4_show_quota_options(struct seq_file *seq,
1804 					   struct super_block *sb)
1805 {
1806 #if defined(CONFIG_QUOTA)
1807 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1808 
1809 	if (sbi->s_jquota_fmt) {
1810 		char *fmtname = "";
1811 
1812 		switch (sbi->s_jquota_fmt) {
1813 		case QFMT_VFS_OLD:
1814 			fmtname = "vfsold";
1815 			break;
1816 		case QFMT_VFS_V0:
1817 			fmtname = "vfsv0";
1818 			break;
1819 		case QFMT_VFS_V1:
1820 			fmtname = "vfsv1";
1821 			break;
1822 		}
1823 		seq_printf(seq, ",jqfmt=%s", fmtname);
1824 	}
1825 
1826 	if (sbi->s_qf_names[USRQUOTA])
1827 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1828 
1829 	if (sbi->s_qf_names[GRPQUOTA])
1830 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1831 #endif
1832 }
1833 
1834 static const char *token2str(int token)
1835 {
1836 	const struct match_token *t;
1837 
1838 	for (t = tokens; t->token != Opt_err; t++)
1839 		if (t->token == token && !strchr(t->pattern, '='))
1840 			break;
1841 	return t->pattern;
1842 }
1843 
1844 /*
1845  * Show an option if
1846  *  - it's set to a non-default value OR
1847  *  - if the per-sb default is different from the global default
1848  */
1849 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1850 			      int nodefs)
1851 {
1852 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1853 	struct ext4_super_block *es = sbi->s_es;
1854 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1855 	const struct mount_opts *m;
1856 	char sep = nodefs ? '\n' : ',';
1857 
1858 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1859 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1860 
1861 	if (sbi->s_sb_block != 1)
1862 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1863 
1864 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1865 		int want_set = m->flags & MOPT_SET;
1866 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1867 		    (m->flags & MOPT_CLEAR_ERR))
1868 			continue;
1869 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1870 			continue; /* skip if same as the default */
1871 		if ((want_set &&
1872 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1873 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1874 			continue; /* select Opt_noFoo vs Opt_Foo */
1875 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1876 	}
1877 
1878 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1879 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1880 		SEQ_OPTS_PRINT("resuid=%u",
1881 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1882 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1883 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1884 		SEQ_OPTS_PRINT("resgid=%u",
1885 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1886 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1887 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1888 		SEQ_OPTS_PUTS("errors=remount-ro");
1889 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1890 		SEQ_OPTS_PUTS("errors=continue");
1891 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1892 		SEQ_OPTS_PUTS("errors=panic");
1893 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1894 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1895 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1896 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1897 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1898 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1899 	if (sb->s_flags & MS_I_VERSION)
1900 		SEQ_OPTS_PUTS("i_version");
1901 	if (nodefs || sbi->s_stripe)
1902 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1903 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1904 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1905 			SEQ_OPTS_PUTS("data=journal");
1906 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1907 			SEQ_OPTS_PUTS("data=ordered");
1908 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1909 			SEQ_OPTS_PUTS("data=writeback");
1910 	}
1911 	if (nodefs ||
1912 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1913 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1914 			       sbi->s_inode_readahead_blks);
1915 
1916 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1917 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1918 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1919 	if (nodefs || sbi->s_max_dir_size_kb)
1920 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1921 	if (test_opt(sb, DATA_ERR_ABORT))
1922 		SEQ_OPTS_PUTS("data_err=abort");
1923 
1924 	ext4_show_quota_options(seq, sb);
1925 	return 0;
1926 }
1927 
1928 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1929 {
1930 	return _ext4_show_options(seq, root->d_sb, 0);
1931 }
1932 
1933 int ext4_seq_options_show(struct seq_file *seq, void *offset)
1934 {
1935 	struct super_block *sb = seq->private;
1936 	int rc;
1937 
1938 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1939 	rc = _ext4_show_options(seq, sb, 1);
1940 	seq_puts(seq, "\n");
1941 	return rc;
1942 }
1943 
1944 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1945 			    int read_only)
1946 {
1947 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1948 	int res = 0;
1949 
1950 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1951 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1952 			 "forcing read-only mode");
1953 		res = MS_RDONLY;
1954 	}
1955 	if (read_only)
1956 		goto done;
1957 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1958 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1959 			 "running e2fsck is recommended");
1960 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
1961 		ext4_msg(sb, KERN_WARNING,
1962 			 "warning: mounting fs with errors, "
1963 			 "running e2fsck is recommended");
1964 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1965 		 le16_to_cpu(es->s_mnt_count) >=
1966 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1967 		ext4_msg(sb, KERN_WARNING,
1968 			 "warning: maximal mount count reached, "
1969 			 "running e2fsck is recommended");
1970 	else if (le32_to_cpu(es->s_checkinterval) &&
1971 		(le32_to_cpu(es->s_lastcheck) +
1972 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1973 		ext4_msg(sb, KERN_WARNING,
1974 			 "warning: checktime reached, "
1975 			 "running e2fsck is recommended");
1976 	if (!sbi->s_journal)
1977 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1978 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1979 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1980 	le16_add_cpu(&es->s_mnt_count, 1);
1981 	es->s_mtime = cpu_to_le32(get_seconds());
1982 	ext4_update_dynamic_rev(sb);
1983 	if (sbi->s_journal)
1984 		ext4_set_feature_journal_needs_recovery(sb);
1985 
1986 	ext4_commit_super(sb, 1);
1987 done:
1988 	if (test_opt(sb, DEBUG))
1989 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1990 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1991 			sb->s_blocksize,
1992 			sbi->s_groups_count,
1993 			EXT4_BLOCKS_PER_GROUP(sb),
1994 			EXT4_INODES_PER_GROUP(sb),
1995 			sbi->s_mount_opt, sbi->s_mount_opt2);
1996 
1997 	cleancache_init_fs(sb);
1998 	return res;
1999 }
2000 
2001 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2002 {
2003 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2004 	struct flex_groups *new_groups;
2005 	int size;
2006 
2007 	if (!sbi->s_log_groups_per_flex)
2008 		return 0;
2009 
2010 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2011 	if (size <= sbi->s_flex_groups_allocated)
2012 		return 0;
2013 
2014 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2015 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2016 	if (!new_groups) {
2017 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2018 			 size / (int) sizeof(struct flex_groups));
2019 		return -ENOMEM;
2020 	}
2021 
2022 	if (sbi->s_flex_groups) {
2023 		memcpy(new_groups, sbi->s_flex_groups,
2024 		       (sbi->s_flex_groups_allocated *
2025 			sizeof(struct flex_groups)));
2026 		kvfree(sbi->s_flex_groups);
2027 	}
2028 	sbi->s_flex_groups = new_groups;
2029 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2030 	return 0;
2031 }
2032 
2033 static int ext4_fill_flex_info(struct super_block *sb)
2034 {
2035 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2036 	struct ext4_group_desc *gdp = NULL;
2037 	ext4_group_t flex_group;
2038 	int i, err;
2039 
2040 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2041 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2042 		sbi->s_log_groups_per_flex = 0;
2043 		return 1;
2044 	}
2045 
2046 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2047 	if (err)
2048 		goto failed;
2049 
2050 	for (i = 0; i < sbi->s_groups_count; i++) {
2051 		gdp = ext4_get_group_desc(sb, i, NULL);
2052 
2053 		flex_group = ext4_flex_group(sbi, i);
2054 		atomic_add(ext4_free_inodes_count(sb, gdp),
2055 			   &sbi->s_flex_groups[flex_group].free_inodes);
2056 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2057 			     &sbi->s_flex_groups[flex_group].free_clusters);
2058 		atomic_add(ext4_used_dirs_count(sb, gdp),
2059 			   &sbi->s_flex_groups[flex_group].used_dirs);
2060 	}
2061 
2062 	return 1;
2063 failed:
2064 	return 0;
2065 }
2066 
2067 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2068 				   struct ext4_group_desc *gdp)
2069 {
2070 	int offset;
2071 	__u16 crc = 0;
2072 	__le32 le_group = cpu_to_le32(block_group);
2073 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2074 
2075 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2076 		/* Use new metadata_csum algorithm */
2077 		__le16 save_csum;
2078 		__u32 csum32;
2079 
2080 		save_csum = gdp->bg_checksum;
2081 		gdp->bg_checksum = 0;
2082 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2083 				     sizeof(le_group));
2084 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2085 				     sbi->s_desc_size);
2086 		gdp->bg_checksum = save_csum;
2087 
2088 		crc = csum32 & 0xFFFF;
2089 		goto out;
2090 	}
2091 
2092 	/* old crc16 code */
2093 	if (!ext4_has_feature_gdt_csum(sb))
2094 		return 0;
2095 
2096 	offset = offsetof(struct ext4_group_desc, bg_checksum);
2097 
2098 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2099 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2100 	crc = crc16(crc, (__u8 *)gdp, offset);
2101 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2102 	/* for checksum of struct ext4_group_desc do the rest...*/
2103 	if (ext4_has_feature_64bit(sb) &&
2104 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2105 		crc = crc16(crc, (__u8 *)gdp + offset,
2106 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2107 				offset);
2108 
2109 out:
2110 	return cpu_to_le16(crc);
2111 }
2112 
2113 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2114 				struct ext4_group_desc *gdp)
2115 {
2116 	if (ext4_has_group_desc_csum(sb) &&
2117 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2118 		return 0;
2119 
2120 	return 1;
2121 }
2122 
2123 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2124 			      struct ext4_group_desc *gdp)
2125 {
2126 	if (!ext4_has_group_desc_csum(sb))
2127 		return;
2128 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2129 }
2130 
2131 /* Called at mount-time, super-block is locked */
2132 static int ext4_check_descriptors(struct super_block *sb,
2133 				  ext4_group_t *first_not_zeroed)
2134 {
2135 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2136 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2137 	ext4_fsblk_t last_block;
2138 	ext4_fsblk_t block_bitmap;
2139 	ext4_fsblk_t inode_bitmap;
2140 	ext4_fsblk_t inode_table;
2141 	int flexbg_flag = 0;
2142 	ext4_group_t i, grp = sbi->s_groups_count;
2143 
2144 	if (ext4_has_feature_flex_bg(sb))
2145 		flexbg_flag = 1;
2146 
2147 	ext4_debug("Checking group descriptors");
2148 
2149 	for (i = 0; i < sbi->s_groups_count; i++) {
2150 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2151 
2152 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2153 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2154 		else
2155 			last_block = first_block +
2156 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2157 
2158 		if ((grp == sbi->s_groups_count) &&
2159 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2160 			grp = i;
2161 
2162 		block_bitmap = ext4_block_bitmap(sb, gdp);
2163 		if (block_bitmap < first_block || block_bitmap > last_block) {
2164 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2165 			       "Block bitmap for group %u not in group "
2166 			       "(block %llu)!", i, block_bitmap);
2167 			return 0;
2168 		}
2169 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2170 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2171 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2172 			       "Inode bitmap for group %u not in group "
2173 			       "(block %llu)!", i, inode_bitmap);
2174 			return 0;
2175 		}
2176 		inode_table = ext4_inode_table(sb, gdp);
2177 		if (inode_table < first_block ||
2178 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2179 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2180 			       "Inode table for group %u not in group "
2181 			       "(block %llu)!", i, inode_table);
2182 			return 0;
2183 		}
2184 		ext4_lock_group(sb, i);
2185 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2186 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2187 				 "Checksum for group %u failed (%u!=%u)",
2188 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2189 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2190 			if (!(sb->s_flags & MS_RDONLY)) {
2191 				ext4_unlock_group(sb, i);
2192 				return 0;
2193 			}
2194 		}
2195 		ext4_unlock_group(sb, i);
2196 		if (!flexbg_flag)
2197 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2198 	}
2199 	if (NULL != first_not_zeroed)
2200 		*first_not_zeroed = grp;
2201 	return 1;
2202 }
2203 
2204 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2205  * the superblock) which were deleted from all directories, but held open by
2206  * a process at the time of a crash.  We walk the list and try to delete these
2207  * inodes at recovery time (only with a read-write filesystem).
2208  *
2209  * In order to keep the orphan inode chain consistent during traversal (in
2210  * case of crash during recovery), we link each inode into the superblock
2211  * orphan list_head and handle it the same way as an inode deletion during
2212  * normal operation (which journals the operations for us).
2213  *
2214  * We only do an iget() and an iput() on each inode, which is very safe if we
2215  * accidentally point at an in-use or already deleted inode.  The worst that
2216  * can happen in this case is that we get a "bit already cleared" message from
2217  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2218  * e2fsck was run on this filesystem, and it must have already done the orphan
2219  * inode cleanup for us, so we can safely abort without any further action.
2220  */
2221 static void ext4_orphan_cleanup(struct super_block *sb,
2222 				struct ext4_super_block *es)
2223 {
2224 	unsigned int s_flags = sb->s_flags;
2225 	int nr_orphans = 0, nr_truncates = 0;
2226 #ifdef CONFIG_QUOTA
2227 	int i;
2228 #endif
2229 	if (!es->s_last_orphan) {
2230 		jbd_debug(4, "no orphan inodes to clean up\n");
2231 		return;
2232 	}
2233 
2234 	if (bdev_read_only(sb->s_bdev)) {
2235 		ext4_msg(sb, KERN_ERR, "write access "
2236 			"unavailable, skipping orphan cleanup");
2237 		return;
2238 	}
2239 
2240 	/* Check if feature set would not allow a r/w mount */
2241 	if (!ext4_feature_set_ok(sb, 0)) {
2242 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2243 			 "unknown ROCOMPAT features");
2244 		return;
2245 	}
2246 
2247 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2248 		/* don't clear list on RO mount w/ errors */
2249 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2250 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2251 				  "clearing orphan list.\n");
2252 			es->s_last_orphan = 0;
2253 		}
2254 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2255 		return;
2256 	}
2257 
2258 	if (s_flags & MS_RDONLY) {
2259 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2260 		sb->s_flags &= ~MS_RDONLY;
2261 	}
2262 #ifdef CONFIG_QUOTA
2263 	/* Needed for iput() to work correctly and not trash data */
2264 	sb->s_flags |= MS_ACTIVE;
2265 	/* Turn on quotas so that they are updated correctly */
2266 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2267 		if (EXT4_SB(sb)->s_qf_names[i]) {
2268 			int ret = ext4_quota_on_mount(sb, i);
2269 			if (ret < 0)
2270 				ext4_msg(sb, KERN_ERR,
2271 					"Cannot turn on journaled "
2272 					"quota: error %d", ret);
2273 		}
2274 	}
2275 #endif
2276 
2277 	while (es->s_last_orphan) {
2278 		struct inode *inode;
2279 
2280 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2281 		if (IS_ERR(inode)) {
2282 			es->s_last_orphan = 0;
2283 			break;
2284 		}
2285 
2286 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2287 		dquot_initialize(inode);
2288 		if (inode->i_nlink) {
2289 			if (test_opt(sb, DEBUG))
2290 				ext4_msg(sb, KERN_DEBUG,
2291 					"%s: truncating inode %lu to %lld bytes",
2292 					__func__, inode->i_ino, inode->i_size);
2293 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2294 				  inode->i_ino, inode->i_size);
2295 			inode_lock(inode);
2296 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2297 			ext4_truncate(inode);
2298 			inode_unlock(inode);
2299 			nr_truncates++;
2300 		} else {
2301 			if (test_opt(sb, DEBUG))
2302 				ext4_msg(sb, KERN_DEBUG,
2303 					"%s: deleting unreferenced inode %lu",
2304 					__func__, inode->i_ino);
2305 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2306 				  inode->i_ino);
2307 			nr_orphans++;
2308 		}
2309 		iput(inode);  /* The delete magic happens here! */
2310 	}
2311 
2312 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2313 
2314 	if (nr_orphans)
2315 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2316 		       PLURAL(nr_orphans));
2317 	if (nr_truncates)
2318 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2319 		       PLURAL(nr_truncates));
2320 #ifdef CONFIG_QUOTA
2321 	/* Turn quotas off */
2322 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2323 		if (sb_dqopt(sb)->files[i])
2324 			dquot_quota_off(sb, i);
2325 	}
2326 #endif
2327 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2328 }
2329 
2330 /*
2331  * Maximal extent format file size.
2332  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2333  * extent format containers, within a sector_t, and within i_blocks
2334  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2335  * so that won't be a limiting factor.
2336  *
2337  * However there is other limiting factor. We do store extents in the form
2338  * of starting block and length, hence the resulting length of the extent
2339  * covering maximum file size must fit into on-disk format containers as
2340  * well. Given that length is always by 1 unit bigger than max unit (because
2341  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2342  *
2343  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2344  */
2345 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2346 {
2347 	loff_t res;
2348 	loff_t upper_limit = MAX_LFS_FILESIZE;
2349 
2350 	/* small i_blocks in vfs inode? */
2351 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2352 		/*
2353 		 * CONFIG_LBDAF is not enabled implies the inode
2354 		 * i_block represent total blocks in 512 bytes
2355 		 * 32 == size of vfs inode i_blocks * 8
2356 		 */
2357 		upper_limit = (1LL << 32) - 1;
2358 
2359 		/* total blocks in file system block size */
2360 		upper_limit >>= (blkbits - 9);
2361 		upper_limit <<= blkbits;
2362 	}
2363 
2364 	/*
2365 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2366 	 * by one fs block, so ee_len can cover the extent of maximum file
2367 	 * size
2368 	 */
2369 	res = (1LL << 32) - 1;
2370 	res <<= blkbits;
2371 
2372 	/* Sanity check against vm- & vfs- imposed limits */
2373 	if (res > upper_limit)
2374 		res = upper_limit;
2375 
2376 	return res;
2377 }
2378 
2379 /*
2380  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2381  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2382  * We need to be 1 filesystem block less than the 2^48 sector limit.
2383  */
2384 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2385 {
2386 	loff_t res = EXT4_NDIR_BLOCKS;
2387 	int meta_blocks;
2388 	loff_t upper_limit;
2389 	/* This is calculated to be the largest file size for a dense, block
2390 	 * mapped file such that the file's total number of 512-byte sectors,
2391 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2392 	 *
2393 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2394 	 * number of 512-byte sectors of the file.
2395 	 */
2396 
2397 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2398 		/*
2399 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2400 		 * the inode i_block field represents total file blocks in
2401 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2402 		 */
2403 		upper_limit = (1LL << 32) - 1;
2404 
2405 		/* total blocks in file system block size */
2406 		upper_limit >>= (bits - 9);
2407 
2408 	} else {
2409 		/*
2410 		 * We use 48 bit ext4_inode i_blocks
2411 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2412 		 * represent total number of blocks in
2413 		 * file system block size
2414 		 */
2415 		upper_limit = (1LL << 48) - 1;
2416 
2417 	}
2418 
2419 	/* indirect blocks */
2420 	meta_blocks = 1;
2421 	/* double indirect blocks */
2422 	meta_blocks += 1 + (1LL << (bits-2));
2423 	/* tripple indirect blocks */
2424 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2425 
2426 	upper_limit -= meta_blocks;
2427 	upper_limit <<= bits;
2428 
2429 	res += 1LL << (bits-2);
2430 	res += 1LL << (2*(bits-2));
2431 	res += 1LL << (3*(bits-2));
2432 	res <<= bits;
2433 	if (res > upper_limit)
2434 		res = upper_limit;
2435 
2436 	if (res > MAX_LFS_FILESIZE)
2437 		res = MAX_LFS_FILESIZE;
2438 
2439 	return res;
2440 }
2441 
2442 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2443 				   ext4_fsblk_t logical_sb_block, int nr)
2444 {
2445 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2446 	ext4_group_t bg, first_meta_bg;
2447 	int has_super = 0;
2448 
2449 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2450 
2451 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2452 		return logical_sb_block + nr + 1;
2453 	bg = sbi->s_desc_per_block * nr;
2454 	if (ext4_bg_has_super(sb, bg))
2455 		has_super = 1;
2456 
2457 	/*
2458 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2459 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2460 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2461 	 * compensate.
2462 	 */
2463 	if (sb->s_blocksize == 1024 && nr == 0 &&
2464 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2465 		has_super++;
2466 
2467 	return (has_super + ext4_group_first_block_no(sb, bg));
2468 }
2469 
2470 /**
2471  * ext4_get_stripe_size: Get the stripe size.
2472  * @sbi: In memory super block info
2473  *
2474  * If we have specified it via mount option, then
2475  * use the mount option value. If the value specified at mount time is
2476  * greater than the blocks per group use the super block value.
2477  * If the super block value is greater than blocks per group return 0.
2478  * Allocator needs it be less than blocks per group.
2479  *
2480  */
2481 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2482 {
2483 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2484 	unsigned long stripe_width =
2485 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2486 	int ret;
2487 
2488 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2489 		ret = sbi->s_stripe;
2490 	else if (stripe_width <= sbi->s_blocks_per_group)
2491 		ret = stripe_width;
2492 	else if (stride <= sbi->s_blocks_per_group)
2493 		ret = stride;
2494 	else
2495 		ret = 0;
2496 
2497 	/*
2498 	 * If the stripe width is 1, this makes no sense and
2499 	 * we set it to 0 to turn off stripe handling code.
2500 	 */
2501 	if (ret <= 1)
2502 		ret = 0;
2503 
2504 	return ret;
2505 }
2506 
2507 /*
2508  * Check whether this filesystem can be mounted based on
2509  * the features present and the RDONLY/RDWR mount requested.
2510  * Returns 1 if this filesystem can be mounted as requested,
2511  * 0 if it cannot be.
2512  */
2513 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2514 {
2515 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2516 		ext4_msg(sb, KERN_ERR,
2517 			"Couldn't mount because of "
2518 			"unsupported optional features (%x)",
2519 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2520 			~EXT4_FEATURE_INCOMPAT_SUPP));
2521 		return 0;
2522 	}
2523 
2524 	if (readonly)
2525 		return 1;
2526 
2527 	if (ext4_has_feature_readonly(sb)) {
2528 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2529 		sb->s_flags |= MS_RDONLY;
2530 		return 1;
2531 	}
2532 
2533 	/* Check that feature set is OK for a read-write mount */
2534 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2535 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2536 			 "unsupported optional features (%x)",
2537 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2538 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2539 		return 0;
2540 	}
2541 	/*
2542 	 * Large file size enabled file system can only be mounted
2543 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2544 	 */
2545 	if (ext4_has_feature_huge_file(sb)) {
2546 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2547 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2548 				 "cannot be mounted RDWR without "
2549 				 "CONFIG_LBDAF");
2550 			return 0;
2551 		}
2552 	}
2553 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2554 		ext4_msg(sb, KERN_ERR,
2555 			 "Can't support bigalloc feature without "
2556 			 "extents feature\n");
2557 		return 0;
2558 	}
2559 
2560 #ifndef CONFIG_QUOTA
2561 	if (ext4_has_feature_quota(sb) && !readonly) {
2562 		ext4_msg(sb, KERN_ERR,
2563 			 "Filesystem with quota feature cannot be mounted RDWR "
2564 			 "without CONFIG_QUOTA");
2565 		return 0;
2566 	}
2567 	if (ext4_has_feature_project(sb) && !readonly) {
2568 		ext4_msg(sb, KERN_ERR,
2569 			 "Filesystem with project quota feature cannot be mounted RDWR "
2570 			 "without CONFIG_QUOTA");
2571 		return 0;
2572 	}
2573 #endif  /* CONFIG_QUOTA */
2574 	return 1;
2575 }
2576 
2577 /*
2578  * This function is called once a day if we have errors logged
2579  * on the file system
2580  */
2581 static void print_daily_error_info(unsigned long arg)
2582 {
2583 	struct super_block *sb = (struct super_block *) arg;
2584 	struct ext4_sb_info *sbi;
2585 	struct ext4_super_block *es;
2586 
2587 	sbi = EXT4_SB(sb);
2588 	es = sbi->s_es;
2589 
2590 	if (es->s_error_count)
2591 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2592 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2593 			 le32_to_cpu(es->s_error_count));
2594 	if (es->s_first_error_time) {
2595 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2596 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2597 		       (int) sizeof(es->s_first_error_func),
2598 		       es->s_first_error_func,
2599 		       le32_to_cpu(es->s_first_error_line));
2600 		if (es->s_first_error_ino)
2601 			printk(": inode %u",
2602 			       le32_to_cpu(es->s_first_error_ino));
2603 		if (es->s_first_error_block)
2604 			printk(": block %llu", (unsigned long long)
2605 			       le64_to_cpu(es->s_first_error_block));
2606 		printk("\n");
2607 	}
2608 	if (es->s_last_error_time) {
2609 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2610 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2611 		       (int) sizeof(es->s_last_error_func),
2612 		       es->s_last_error_func,
2613 		       le32_to_cpu(es->s_last_error_line));
2614 		if (es->s_last_error_ino)
2615 			printk(": inode %u",
2616 			       le32_to_cpu(es->s_last_error_ino));
2617 		if (es->s_last_error_block)
2618 			printk(": block %llu", (unsigned long long)
2619 			       le64_to_cpu(es->s_last_error_block));
2620 		printk("\n");
2621 	}
2622 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2623 }
2624 
2625 /* Find next suitable group and run ext4_init_inode_table */
2626 static int ext4_run_li_request(struct ext4_li_request *elr)
2627 {
2628 	struct ext4_group_desc *gdp = NULL;
2629 	ext4_group_t group, ngroups;
2630 	struct super_block *sb;
2631 	unsigned long timeout = 0;
2632 	int ret = 0;
2633 
2634 	sb = elr->lr_super;
2635 	ngroups = EXT4_SB(sb)->s_groups_count;
2636 
2637 	sb_start_write(sb);
2638 	for (group = elr->lr_next_group; group < ngroups; group++) {
2639 		gdp = ext4_get_group_desc(sb, group, NULL);
2640 		if (!gdp) {
2641 			ret = 1;
2642 			break;
2643 		}
2644 
2645 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2646 			break;
2647 	}
2648 
2649 	if (group >= ngroups)
2650 		ret = 1;
2651 
2652 	if (!ret) {
2653 		timeout = jiffies;
2654 		ret = ext4_init_inode_table(sb, group,
2655 					    elr->lr_timeout ? 0 : 1);
2656 		if (elr->lr_timeout == 0) {
2657 			timeout = (jiffies - timeout) *
2658 				  elr->lr_sbi->s_li_wait_mult;
2659 			elr->lr_timeout = timeout;
2660 		}
2661 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2662 		elr->lr_next_group = group + 1;
2663 	}
2664 	sb_end_write(sb);
2665 
2666 	return ret;
2667 }
2668 
2669 /*
2670  * Remove lr_request from the list_request and free the
2671  * request structure. Should be called with li_list_mtx held
2672  */
2673 static void ext4_remove_li_request(struct ext4_li_request *elr)
2674 {
2675 	struct ext4_sb_info *sbi;
2676 
2677 	if (!elr)
2678 		return;
2679 
2680 	sbi = elr->lr_sbi;
2681 
2682 	list_del(&elr->lr_request);
2683 	sbi->s_li_request = NULL;
2684 	kfree(elr);
2685 }
2686 
2687 static void ext4_unregister_li_request(struct super_block *sb)
2688 {
2689 	mutex_lock(&ext4_li_mtx);
2690 	if (!ext4_li_info) {
2691 		mutex_unlock(&ext4_li_mtx);
2692 		return;
2693 	}
2694 
2695 	mutex_lock(&ext4_li_info->li_list_mtx);
2696 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2697 	mutex_unlock(&ext4_li_info->li_list_mtx);
2698 	mutex_unlock(&ext4_li_mtx);
2699 }
2700 
2701 static struct task_struct *ext4_lazyinit_task;
2702 
2703 /*
2704  * This is the function where ext4lazyinit thread lives. It walks
2705  * through the request list searching for next scheduled filesystem.
2706  * When such a fs is found, run the lazy initialization request
2707  * (ext4_rn_li_request) and keep track of the time spend in this
2708  * function. Based on that time we compute next schedule time of
2709  * the request. When walking through the list is complete, compute
2710  * next waking time and put itself into sleep.
2711  */
2712 static int ext4_lazyinit_thread(void *arg)
2713 {
2714 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2715 	struct list_head *pos, *n;
2716 	struct ext4_li_request *elr;
2717 	unsigned long next_wakeup, cur;
2718 
2719 	BUG_ON(NULL == eli);
2720 
2721 cont_thread:
2722 	while (true) {
2723 		next_wakeup = MAX_JIFFY_OFFSET;
2724 
2725 		mutex_lock(&eli->li_list_mtx);
2726 		if (list_empty(&eli->li_request_list)) {
2727 			mutex_unlock(&eli->li_list_mtx);
2728 			goto exit_thread;
2729 		}
2730 
2731 		list_for_each_safe(pos, n, &eli->li_request_list) {
2732 			elr = list_entry(pos, struct ext4_li_request,
2733 					 lr_request);
2734 
2735 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2736 				if (ext4_run_li_request(elr) != 0) {
2737 					/* error, remove the lazy_init job */
2738 					ext4_remove_li_request(elr);
2739 					continue;
2740 				}
2741 			}
2742 
2743 			if (time_before(elr->lr_next_sched, next_wakeup))
2744 				next_wakeup = elr->lr_next_sched;
2745 		}
2746 		mutex_unlock(&eli->li_list_mtx);
2747 
2748 		try_to_freeze();
2749 
2750 		cur = jiffies;
2751 		if ((time_after_eq(cur, next_wakeup)) ||
2752 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2753 			cond_resched();
2754 			continue;
2755 		}
2756 
2757 		schedule_timeout_interruptible(next_wakeup - cur);
2758 
2759 		if (kthread_should_stop()) {
2760 			ext4_clear_request_list();
2761 			goto exit_thread;
2762 		}
2763 	}
2764 
2765 exit_thread:
2766 	/*
2767 	 * It looks like the request list is empty, but we need
2768 	 * to check it under the li_list_mtx lock, to prevent any
2769 	 * additions into it, and of course we should lock ext4_li_mtx
2770 	 * to atomically free the list and ext4_li_info, because at
2771 	 * this point another ext4 filesystem could be registering
2772 	 * new one.
2773 	 */
2774 	mutex_lock(&ext4_li_mtx);
2775 	mutex_lock(&eli->li_list_mtx);
2776 	if (!list_empty(&eli->li_request_list)) {
2777 		mutex_unlock(&eli->li_list_mtx);
2778 		mutex_unlock(&ext4_li_mtx);
2779 		goto cont_thread;
2780 	}
2781 	mutex_unlock(&eli->li_list_mtx);
2782 	kfree(ext4_li_info);
2783 	ext4_li_info = NULL;
2784 	mutex_unlock(&ext4_li_mtx);
2785 
2786 	return 0;
2787 }
2788 
2789 static void ext4_clear_request_list(void)
2790 {
2791 	struct list_head *pos, *n;
2792 	struct ext4_li_request *elr;
2793 
2794 	mutex_lock(&ext4_li_info->li_list_mtx);
2795 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2796 		elr = list_entry(pos, struct ext4_li_request,
2797 				 lr_request);
2798 		ext4_remove_li_request(elr);
2799 	}
2800 	mutex_unlock(&ext4_li_info->li_list_mtx);
2801 }
2802 
2803 static int ext4_run_lazyinit_thread(void)
2804 {
2805 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2806 					 ext4_li_info, "ext4lazyinit");
2807 	if (IS_ERR(ext4_lazyinit_task)) {
2808 		int err = PTR_ERR(ext4_lazyinit_task);
2809 		ext4_clear_request_list();
2810 		kfree(ext4_li_info);
2811 		ext4_li_info = NULL;
2812 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2813 				 "initialization thread\n",
2814 				 err);
2815 		return err;
2816 	}
2817 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2818 	return 0;
2819 }
2820 
2821 /*
2822  * Check whether it make sense to run itable init. thread or not.
2823  * If there is at least one uninitialized inode table, return
2824  * corresponding group number, else the loop goes through all
2825  * groups and return total number of groups.
2826  */
2827 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2828 {
2829 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2830 	struct ext4_group_desc *gdp = NULL;
2831 
2832 	for (group = 0; group < ngroups; group++) {
2833 		gdp = ext4_get_group_desc(sb, group, NULL);
2834 		if (!gdp)
2835 			continue;
2836 
2837 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2838 			break;
2839 	}
2840 
2841 	return group;
2842 }
2843 
2844 static int ext4_li_info_new(void)
2845 {
2846 	struct ext4_lazy_init *eli = NULL;
2847 
2848 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2849 	if (!eli)
2850 		return -ENOMEM;
2851 
2852 	INIT_LIST_HEAD(&eli->li_request_list);
2853 	mutex_init(&eli->li_list_mtx);
2854 
2855 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2856 
2857 	ext4_li_info = eli;
2858 
2859 	return 0;
2860 }
2861 
2862 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2863 					    ext4_group_t start)
2864 {
2865 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2866 	struct ext4_li_request *elr;
2867 
2868 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2869 	if (!elr)
2870 		return NULL;
2871 
2872 	elr->lr_super = sb;
2873 	elr->lr_sbi = sbi;
2874 	elr->lr_next_group = start;
2875 
2876 	/*
2877 	 * Randomize first schedule time of the request to
2878 	 * spread the inode table initialization requests
2879 	 * better.
2880 	 */
2881 	elr->lr_next_sched = jiffies + (prandom_u32() %
2882 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
2883 	return elr;
2884 }
2885 
2886 int ext4_register_li_request(struct super_block *sb,
2887 			     ext4_group_t first_not_zeroed)
2888 {
2889 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2890 	struct ext4_li_request *elr = NULL;
2891 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2892 	int ret = 0;
2893 
2894 	mutex_lock(&ext4_li_mtx);
2895 	if (sbi->s_li_request != NULL) {
2896 		/*
2897 		 * Reset timeout so it can be computed again, because
2898 		 * s_li_wait_mult might have changed.
2899 		 */
2900 		sbi->s_li_request->lr_timeout = 0;
2901 		goto out;
2902 	}
2903 
2904 	if (first_not_zeroed == ngroups ||
2905 	    (sb->s_flags & MS_RDONLY) ||
2906 	    !test_opt(sb, INIT_INODE_TABLE))
2907 		goto out;
2908 
2909 	elr = ext4_li_request_new(sb, first_not_zeroed);
2910 	if (!elr) {
2911 		ret = -ENOMEM;
2912 		goto out;
2913 	}
2914 
2915 	if (NULL == ext4_li_info) {
2916 		ret = ext4_li_info_new();
2917 		if (ret)
2918 			goto out;
2919 	}
2920 
2921 	mutex_lock(&ext4_li_info->li_list_mtx);
2922 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2923 	mutex_unlock(&ext4_li_info->li_list_mtx);
2924 
2925 	sbi->s_li_request = elr;
2926 	/*
2927 	 * set elr to NULL here since it has been inserted to
2928 	 * the request_list and the removal and free of it is
2929 	 * handled by ext4_clear_request_list from now on.
2930 	 */
2931 	elr = NULL;
2932 
2933 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2934 		ret = ext4_run_lazyinit_thread();
2935 		if (ret)
2936 			goto out;
2937 	}
2938 out:
2939 	mutex_unlock(&ext4_li_mtx);
2940 	if (ret)
2941 		kfree(elr);
2942 	return ret;
2943 }
2944 
2945 /*
2946  * We do not need to lock anything since this is called on
2947  * module unload.
2948  */
2949 static void ext4_destroy_lazyinit_thread(void)
2950 {
2951 	/*
2952 	 * If thread exited earlier
2953 	 * there's nothing to be done.
2954 	 */
2955 	if (!ext4_li_info || !ext4_lazyinit_task)
2956 		return;
2957 
2958 	kthread_stop(ext4_lazyinit_task);
2959 }
2960 
2961 static int set_journal_csum_feature_set(struct super_block *sb)
2962 {
2963 	int ret = 1;
2964 	int compat, incompat;
2965 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2966 
2967 	if (ext4_has_metadata_csum(sb)) {
2968 		/* journal checksum v3 */
2969 		compat = 0;
2970 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
2971 	} else {
2972 		/* journal checksum v1 */
2973 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
2974 		incompat = 0;
2975 	}
2976 
2977 	jbd2_journal_clear_features(sbi->s_journal,
2978 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2979 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
2980 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
2981 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2982 		ret = jbd2_journal_set_features(sbi->s_journal,
2983 				compat, 0,
2984 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
2985 				incompat);
2986 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2987 		ret = jbd2_journal_set_features(sbi->s_journal,
2988 				compat, 0,
2989 				incompat);
2990 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2991 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2992 	} else {
2993 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2994 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2995 	}
2996 
2997 	return ret;
2998 }
2999 
3000 /*
3001  * Note: calculating the overhead so we can be compatible with
3002  * historical BSD practice is quite difficult in the face of
3003  * clusters/bigalloc.  This is because multiple metadata blocks from
3004  * different block group can end up in the same allocation cluster.
3005  * Calculating the exact overhead in the face of clustered allocation
3006  * requires either O(all block bitmaps) in memory or O(number of block
3007  * groups**2) in time.  We will still calculate the superblock for
3008  * older file systems --- and if we come across with a bigalloc file
3009  * system with zero in s_overhead_clusters the estimate will be close to
3010  * correct especially for very large cluster sizes --- but for newer
3011  * file systems, it's better to calculate this figure once at mkfs
3012  * time, and store it in the superblock.  If the superblock value is
3013  * present (even for non-bigalloc file systems), we will use it.
3014  */
3015 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3016 			  char *buf)
3017 {
3018 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3019 	struct ext4_group_desc	*gdp;
3020 	ext4_fsblk_t		first_block, last_block, b;
3021 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3022 	int			s, j, count = 0;
3023 
3024 	if (!ext4_has_feature_bigalloc(sb))
3025 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3026 			sbi->s_itb_per_group + 2);
3027 
3028 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3029 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3030 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3031 	for (i = 0; i < ngroups; i++) {
3032 		gdp = ext4_get_group_desc(sb, i, NULL);
3033 		b = ext4_block_bitmap(sb, gdp);
3034 		if (b >= first_block && b <= last_block) {
3035 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3036 			count++;
3037 		}
3038 		b = ext4_inode_bitmap(sb, gdp);
3039 		if (b >= first_block && b <= last_block) {
3040 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3041 			count++;
3042 		}
3043 		b = ext4_inode_table(sb, gdp);
3044 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3045 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3046 				int c = EXT4_B2C(sbi, b - first_block);
3047 				ext4_set_bit(c, buf);
3048 				count++;
3049 			}
3050 		if (i != grp)
3051 			continue;
3052 		s = 0;
3053 		if (ext4_bg_has_super(sb, grp)) {
3054 			ext4_set_bit(s++, buf);
3055 			count++;
3056 		}
3057 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3058 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3059 			count++;
3060 		}
3061 	}
3062 	if (!count)
3063 		return 0;
3064 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3065 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3066 }
3067 
3068 /*
3069  * Compute the overhead and stash it in sbi->s_overhead
3070  */
3071 int ext4_calculate_overhead(struct super_block *sb)
3072 {
3073 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3074 	struct ext4_super_block *es = sbi->s_es;
3075 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3076 	ext4_fsblk_t overhead = 0;
3077 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3078 
3079 	if (!buf)
3080 		return -ENOMEM;
3081 
3082 	/*
3083 	 * Compute the overhead (FS structures).  This is constant
3084 	 * for a given filesystem unless the number of block groups
3085 	 * changes so we cache the previous value until it does.
3086 	 */
3087 
3088 	/*
3089 	 * All of the blocks before first_data_block are overhead
3090 	 */
3091 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3092 
3093 	/*
3094 	 * Add the overhead found in each block group
3095 	 */
3096 	for (i = 0; i < ngroups; i++) {
3097 		int blks;
3098 
3099 		blks = count_overhead(sb, i, buf);
3100 		overhead += blks;
3101 		if (blks)
3102 			memset(buf, 0, PAGE_SIZE);
3103 		cond_resched();
3104 	}
3105 	/* Add the internal journal blocks as well */
3106 	if (sbi->s_journal && !sbi->journal_bdev)
3107 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3108 
3109 	sbi->s_overhead = overhead;
3110 	smp_wmb();
3111 	free_page((unsigned long) buf);
3112 	return 0;
3113 }
3114 
3115 static void ext4_set_resv_clusters(struct super_block *sb)
3116 {
3117 	ext4_fsblk_t resv_clusters;
3118 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3119 
3120 	/*
3121 	 * There's no need to reserve anything when we aren't using extents.
3122 	 * The space estimates are exact, there are no unwritten extents,
3123 	 * hole punching doesn't need new metadata... This is needed especially
3124 	 * to keep ext2/3 backward compatibility.
3125 	 */
3126 	if (!ext4_has_feature_extents(sb))
3127 		return;
3128 	/*
3129 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3130 	 * This should cover the situations where we can not afford to run
3131 	 * out of space like for example punch hole, or converting
3132 	 * unwritten extents in delalloc path. In most cases such
3133 	 * allocation would require 1, or 2 blocks, higher numbers are
3134 	 * very rare.
3135 	 */
3136 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3137 			 sbi->s_cluster_bits);
3138 
3139 	do_div(resv_clusters, 50);
3140 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3141 
3142 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3143 }
3144 
3145 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3146 {
3147 	char *orig_data = kstrdup(data, GFP_KERNEL);
3148 	struct buffer_head *bh;
3149 	struct ext4_super_block *es = NULL;
3150 	struct ext4_sb_info *sbi;
3151 	ext4_fsblk_t block;
3152 	ext4_fsblk_t sb_block = get_sb_block(&data);
3153 	ext4_fsblk_t logical_sb_block;
3154 	unsigned long offset = 0;
3155 	unsigned long journal_devnum = 0;
3156 	unsigned long def_mount_opts;
3157 	struct inode *root;
3158 	const char *descr;
3159 	int ret = -ENOMEM;
3160 	int blocksize, clustersize;
3161 	unsigned int db_count;
3162 	unsigned int i;
3163 	int needs_recovery, has_huge_files, has_bigalloc;
3164 	__u64 blocks_count;
3165 	int err = 0;
3166 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3167 	ext4_group_t first_not_zeroed;
3168 
3169 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3170 	if (!sbi)
3171 		goto out_free_orig;
3172 
3173 	sbi->s_blockgroup_lock =
3174 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3175 	if (!sbi->s_blockgroup_lock) {
3176 		kfree(sbi);
3177 		goto out_free_orig;
3178 	}
3179 	sb->s_fs_info = sbi;
3180 	sbi->s_sb = sb;
3181 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3182 	sbi->s_sb_block = sb_block;
3183 	if (sb->s_bdev->bd_part)
3184 		sbi->s_sectors_written_start =
3185 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3186 
3187 	/* Cleanup superblock name */
3188 	strreplace(sb->s_id, '/', '!');
3189 
3190 	/* -EINVAL is default */
3191 	ret = -EINVAL;
3192 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3193 	if (!blocksize) {
3194 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3195 		goto out_fail;
3196 	}
3197 
3198 	/*
3199 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3200 	 * block sizes.  We need to calculate the offset from buffer start.
3201 	 */
3202 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3203 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3204 		offset = do_div(logical_sb_block, blocksize);
3205 	} else {
3206 		logical_sb_block = sb_block;
3207 	}
3208 
3209 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3210 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3211 		goto out_fail;
3212 	}
3213 	/*
3214 	 * Note: s_es must be initialized as soon as possible because
3215 	 *       some ext4 macro-instructions depend on its value
3216 	 */
3217 	es = (struct ext4_super_block *) (bh->b_data + offset);
3218 	sbi->s_es = es;
3219 	sb->s_magic = le16_to_cpu(es->s_magic);
3220 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3221 		goto cantfind_ext4;
3222 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3223 
3224 	/* Warn if metadata_csum and gdt_csum are both set. */
3225 	if (ext4_has_feature_metadata_csum(sb) &&
3226 	    ext4_has_feature_gdt_csum(sb))
3227 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3228 			     "redundant flags; please run fsck.");
3229 
3230 	/* Check for a known checksum algorithm */
3231 	if (!ext4_verify_csum_type(sb, es)) {
3232 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3233 			 "unknown checksum algorithm.");
3234 		silent = 1;
3235 		goto cantfind_ext4;
3236 	}
3237 
3238 	/* Load the checksum driver */
3239 	if (ext4_has_feature_metadata_csum(sb)) {
3240 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3241 		if (IS_ERR(sbi->s_chksum_driver)) {
3242 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3243 			ret = PTR_ERR(sbi->s_chksum_driver);
3244 			sbi->s_chksum_driver = NULL;
3245 			goto failed_mount;
3246 		}
3247 	}
3248 
3249 	/* Check superblock checksum */
3250 	if (!ext4_superblock_csum_verify(sb, es)) {
3251 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3252 			 "invalid superblock checksum.  Run e2fsck?");
3253 		silent = 1;
3254 		ret = -EFSBADCRC;
3255 		goto cantfind_ext4;
3256 	}
3257 
3258 	/* Precompute checksum seed for all metadata */
3259 	if (ext4_has_feature_csum_seed(sb))
3260 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3261 	else if (ext4_has_metadata_csum(sb))
3262 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3263 					       sizeof(es->s_uuid));
3264 
3265 	/* Set defaults before we parse the mount options */
3266 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3267 	set_opt(sb, INIT_INODE_TABLE);
3268 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3269 		set_opt(sb, DEBUG);
3270 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3271 		set_opt(sb, GRPID);
3272 	if (def_mount_opts & EXT4_DEFM_UID16)
3273 		set_opt(sb, NO_UID32);
3274 	/* xattr user namespace & acls are now defaulted on */
3275 	set_opt(sb, XATTR_USER);
3276 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3277 	set_opt(sb, POSIX_ACL);
3278 #endif
3279 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3280 	if (ext4_has_metadata_csum(sb))
3281 		set_opt(sb, JOURNAL_CHECKSUM);
3282 
3283 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3284 		set_opt(sb, JOURNAL_DATA);
3285 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3286 		set_opt(sb, ORDERED_DATA);
3287 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3288 		set_opt(sb, WRITEBACK_DATA);
3289 
3290 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3291 		set_opt(sb, ERRORS_PANIC);
3292 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3293 		set_opt(sb, ERRORS_CONT);
3294 	else
3295 		set_opt(sb, ERRORS_RO);
3296 	/* block_validity enabled by default; disable with noblock_validity */
3297 	set_opt(sb, BLOCK_VALIDITY);
3298 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3299 		set_opt(sb, DISCARD);
3300 
3301 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3302 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3303 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3304 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3305 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3306 
3307 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3308 		set_opt(sb, BARRIER);
3309 
3310 	/*
3311 	 * enable delayed allocation by default
3312 	 * Use -o nodelalloc to turn it off
3313 	 */
3314 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3315 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3316 		set_opt(sb, DELALLOC);
3317 
3318 	/*
3319 	 * set default s_li_wait_mult for lazyinit, for the case there is
3320 	 * no mount option specified.
3321 	 */
3322 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3323 
3324 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3325 			   &journal_devnum, &journal_ioprio, 0)) {
3326 		ext4_msg(sb, KERN_WARNING,
3327 			 "failed to parse options in superblock: %s",
3328 			 sbi->s_es->s_mount_opts);
3329 	}
3330 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3331 	if (!parse_options((char *) data, sb, &journal_devnum,
3332 			   &journal_ioprio, 0))
3333 		goto failed_mount;
3334 
3335 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3336 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3337 			    "with data=journal disables delayed "
3338 			    "allocation and O_DIRECT support!\n");
3339 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3340 			ext4_msg(sb, KERN_ERR, "can't mount with "
3341 				 "both data=journal and delalloc");
3342 			goto failed_mount;
3343 		}
3344 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3345 			ext4_msg(sb, KERN_ERR, "can't mount with "
3346 				 "both data=journal and dioread_nolock");
3347 			goto failed_mount;
3348 		}
3349 		if (test_opt(sb, DAX)) {
3350 			ext4_msg(sb, KERN_ERR, "can't mount with "
3351 				 "both data=journal and dax");
3352 			goto failed_mount;
3353 		}
3354 		if (test_opt(sb, DELALLOC))
3355 			clear_opt(sb, DELALLOC);
3356 	} else {
3357 		sb->s_iflags |= SB_I_CGROUPWB;
3358 	}
3359 
3360 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3361 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3362 
3363 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3364 	    (ext4_has_compat_features(sb) ||
3365 	     ext4_has_ro_compat_features(sb) ||
3366 	     ext4_has_incompat_features(sb)))
3367 		ext4_msg(sb, KERN_WARNING,
3368 		       "feature flags set on rev 0 fs, "
3369 		       "running e2fsck is recommended");
3370 
3371 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3372 		set_opt2(sb, HURD_COMPAT);
3373 		if (ext4_has_feature_64bit(sb)) {
3374 			ext4_msg(sb, KERN_ERR,
3375 				 "The Hurd can't support 64-bit file systems");
3376 			goto failed_mount;
3377 		}
3378 	}
3379 
3380 	if (IS_EXT2_SB(sb)) {
3381 		if (ext2_feature_set_ok(sb))
3382 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3383 				 "using the ext4 subsystem");
3384 		else {
3385 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3386 				 "to feature incompatibilities");
3387 			goto failed_mount;
3388 		}
3389 	}
3390 
3391 	if (IS_EXT3_SB(sb)) {
3392 		if (ext3_feature_set_ok(sb))
3393 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3394 				 "using the ext4 subsystem");
3395 		else {
3396 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3397 				 "to feature incompatibilities");
3398 			goto failed_mount;
3399 		}
3400 	}
3401 
3402 	/*
3403 	 * Check feature flags regardless of the revision level, since we
3404 	 * previously didn't change the revision level when setting the flags,
3405 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3406 	 */
3407 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3408 		goto failed_mount;
3409 
3410 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3411 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3412 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3413 		ext4_msg(sb, KERN_ERR,
3414 		       "Unsupported filesystem blocksize %d", blocksize);
3415 		goto failed_mount;
3416 	}
3417 
3418 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3419 		if (blocksize != PAGE_SIZE) {
3420 			ext4_msg(sb, KERN_ERR,
3421 					"error: unsupported blocksize for dax");
3422 			goto failed_mount;
3423 		}
3424 		if (!sb->s_bdev->bd_disk->fops->direct_access) {
3425 			ext4_msg(sb, KERN_ERR,
3426 					"error: device does not support dax");
3427 			goto failed_mount;
3428 		}
3429 	}
3430 
3431 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3432 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3433 			 es->s_encryption_level);
3434 		goto failed_mount;
3435 	}
3436 
3437 	if (sb->s_blocksize != blocksize) {
3438 		/* Validate the filesystem blocksize */
3439 		if (!sb_set_blocksize(sb, blocksize)) {
3440 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3441 					blocksize);
3442 			goto failed_mount;
3443 		}
3444 
3445 		brelse(bh);
3446 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3447 		offset = do_div(logical_sb_block, blocksize);
3448 		bh = sb_bread_unmovable(sb, logical_sb_block);
3449 		if (!bh) {
3450 			ext4_msg(sb, KERN_ERR,
3451 			       "Can't read superblock on 2nd try");
3452 			goto failed_mount;
3453 		}
3454 		es = (struct ext4_super_block *)(bh->b_data + offset);
3455 		sbi->s_es = es;
3456 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3457 			ext4_msg(sb, KERN_ERR,
3458 			       "Magic mismatch, very weird!");
3459 			goto failed_mount;
3460 		}
3461 	}
3462 
3463 	has_huge_files = ext4_has_feature_huge_file(sb);
3464 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3465 						      has_huge_files);
3466 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3467 
3468 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3469 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3470 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3471 	} else {
3472 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3473 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3474 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3475 		    (!is_power_of_2(sbi->s_inode_size)) ||
3476 		    (sbi->s_inode_size > blocksize)) {
3477 			ext4_msg(sb, KERN_ERR,
3478 			       "unsupported inode size: %d",
3479 			       sbi->s_inode_size);
3480 			goto failed_mount;
3481 		}
3482 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3483 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3484 	}
3485 
3486 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3487 	if (ext4_has_feature_64bit(sb)) {
3488 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3489 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3490 		    !is_power_of_2(sbi->s_desc_size)) {
3491 			ext4_msg(sb, KERN_ERR,
3492 			       "unsupported descriptor size %lu",
3493 			       sbi->s_desc_size);
3494 			goto failed_mount;
3495 		}
3496 	} else
3497 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3498 
3499 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3500 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3501 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3502 		goto cantfind_ext4;
3503 
3504 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3505 	if (sbi->s_inodes_per_block == 0)
3506 		goto cantfind_ext4;
3507 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3508 					sbi->s_inodes_per_block;
3509 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3510 	sbi->s_sbh = bh;
3511 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3512 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3513 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3514 
3515 	for (i = 0; i < 4; i++)
3516 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3517 	sbi->s_def_hash_version = es->s_def_hash_version;
3518 	if (ext4_has_feature_dir_index(sb)) {
3519 		i = le32_to_cpu(es->s_flags);
3520 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3521 			sbi->s_hash_unsigned = 3;
3522 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3523 #ifdef __CHAR_UNSIGNED__
3524 			if (!(sb->s_flags & MS_RDONLY))
3525 				es->s_flags |=
3526 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3527 			sbi->s_hash_unsigned = 3;
3528 #else
3529 			if (!(sb->s_flags & MS_RDONLY))
3530 				es->s_flags |=
3531 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3532 #endif
3533 		}
3534 	}
3535 
3536 	/* Handle clustersize */
3537 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3538 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3539 	if (has_bigalloc) {
3540 		if (clustersize < blocksize) {
3541 			ext4_msg(sb, KERN_ERR,
3542 				 "cluster size (%d) smaller than "
3543 				 "block size (%d)", clustersize, blocksize);
3544 			goto failed_mount;
3545 		}
3546 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3547 			le32_to_cpu(es->s_log_block_size);
3548 		sbi->s_clusters_per_group =
3549 			le32_to_cpu(es->s_clusters_per_group);
3550 		if (sbi->s_clusters_per_group > blocksize * 8) {
3551 			ext4_msg(sb, KERN_ERR,
3552 				 "#clusters per group too big: %lu",
3553 				 sbi->s_clusters_per_group);
3554 			goto failed_mount;
3555 		}
3556 		if (sbi->s_blocks_per_group !=
3557 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3558 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3559 				 "clusters per group (%lu) inconsistent",
3560 				 sbi->s_blocks_per_group,
3561 				 sbi->s_clusters_per_group);
3562 			goto failed_mount;
3563 		}
3564 	} else {
3565 		if (clustersize != blocksize) {
3566 			ext4_warning(sb, "fragment/cluster size (%d) != "
3567 				     "block size (%d)", clustersize,
3568 				     blocksize);
3569 			clustersize = blocksize;
3570 		}
3571 		if (sbi->s_blocks_per_group > blocksize * 8) {
3572 			ext4_msg(sb, KERN_ERR,
3573 				 "#blocks per group too big: %lu",
3574 				 sbi->s_blocks_per_group);
3575 			goto failed_mount;
3576 		}
3577 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3578 		sbi->s_cluster_bits = 0;
3579 	}
3580 	sbi->s_cluster_ratio = clustersize / blocksize;
3581 
3582 	if (sbi->s_inodes_per_group > blocksize * 8) {
3583 		ext4_msg(sb, KERN_ERR,
3584 		       "#inodes per group too big: %lu",
3585 		       sbi->s_inodes_per_group);
3586 		goto failed_mount;
3587 	}
3588 
3589 	/* Do we have standard group size of clustersize * 8 blocks ? */
3590 	if (sbi->s_blocks_per_group == clustersize << 3)
3591 		set_opt2(sb, STD_GROUP_SIZE);
3592 
3593 	/*
3594 	 * Test whether we have more sectors than will fit in sector_t,
3595 	 * and whether the max offset is addressable by the page cache.
3596 	 */
3597 	err = generic_check_addressable(sb->s_blocksize_bits,
3598 					ext4_blocks_count(es));
3599 	if (err) {
3600 		ext4_msg(sb, KERN_ERR, "filesystem"
3601 			 " too large to mount safely on this system");
3602 		if (sizeof(sector_t) < 8)
3603 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3604 		goto failed_mount;
3605 	}
3606 
3607 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3608 		goto cantfind_ext4;
3609 
3610 	/* check blocks count against device size */
3611 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3612 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3613 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3614 		       "exceeds size of device (%llu blocks)",
3615 		       ext4_blocks_count(es), blocks_count);
3616 		goto failed_mount;
3617 	}
3618 
3619 	/*
3620 	 * It makes no sense for the first data block to be beyond the end
3621 	 * of the filesystem.
3622 	 */
3623 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3624 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3625 			 "block %u is beyond end of filesystem (%llu)",
3626 			 le32_to_cpu(es->s_first_data_block),
3627 			 ext4_blocks_count(es));
3628 		goto failed_mount;
3629 	}
3630 	blocks_count = (ext4_blocks_count(es) -
3631 			le32_to_cpu(es->s_first_data_block) +
3632 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3633 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3634 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3635 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3636 		       "(block count %llu, first data block %u, "
3637 		       "blocks per group %lu)", sbi->s_groups_count,
3638 		       ext4_blocks_count(es),
3639 		       le32_to_cpu(es->s_first_data_block),
3640 		       EXT4_BLOCKS_PER_GROUP(sb));
3641 		goto failed_mount;
3642 	}
3643 	sbi->s_groups_count = blocks_count;
3644 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3645 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3646 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3647 		   EXT4_DESC_PER_BLOCK(sb);
3648 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3649 					  sizeof(struct buffer_head *),
3650 					  GFP_KERNEL);
3651 	if (sbi->s_group_desc == NULL) {
3652 		ext4_msg(sb, KERN_ERR, "not enough memory");
3653 		ret = -ENOMEM;
3654 		goto failed_mount;
3655 	}
3656 
3657 	bgl_lock_init(sbi->s_blockgroup_lock);
3658 
3659 	for (i = 0; i < db_count; i++) {
3660 		block = descriptor_loc(sb, logical_sb_block, i);
3661 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3662 		if (!sbi->s_group_desc[i]) {
3663 			ext4_msg(sb, KERN_ERR,
3664 			       "can't read group descriptor %d", i);
3665 			db_count = i;
3666 			goto failed_mount2;
3667 		}
3668 	}
3669 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3670 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3671 		ret = -EFSCORRUPTED;
3672 		goto failed_mount2;
3673 	}
3674 
3675 	sbi->s_gdb_count = db_count;
3676 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3677 	spin_lock_init(&sbi->s_next_gen_lock);
3678 
3679 	setup_timer(&sbi->s_err_report, print_daily_error_info,
3680 		(unsigned long) sb);
3681 
3682 	/* Register extent status tree shrinker */
3683 	if (ext4_es_register_shrinker(sbi))
3684 		goto failed_mount3;
3685 
3686 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3687 	sbi->s_extent_max_zeroout_kb = 32;
3688 
3689 	/*
3690 	 * set up enough so that it can read an inode
3691 	 */
3692 	sb->s_op = &ext4_sops;
3693 	sb->s_export_op = &ext4_export_ops;
3694 	sb->s_xattr = ext4_xattr_handlers;
3695 #ifdef CONFIG_QUOTA
3696 	sb->dq_op = &ext4_quota_operations;
3697 	if (ext4_has_feature_quota(sb))
3698 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
3699 	else
3700 		sb->s_qcop = &ext4_qctl_operations;
3701 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3702 #endif
3703 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3704 
3705 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3706 	mutex_init(&sbi->s_orphan_lock);
3707 
3708 	sb->s_root = NULL;
3709 
3710 	needs_recovery = (es->s_last_orphan != 0 ||
3711 			  ext4_has_feature_journal_needs_recovery(sb));
3712 
3713 	if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3714 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3715 			goto failed_mount3a;
3716 
3717 	/*
3718 	 * The first inode we look at is the journal inode.  Don't try
3719 	 * root first: it may be modified in the journal!
3720 	 */
3721 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3722 		if (ext4_load_journal(sb, es, journal_devnum))
3723 			goto failed_mount3a;
3724 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3725 		   ext4_has_feature_journal_needs_recovery(sb)) {
3726 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3727 		       "suppressed and not mounted read-only");
3728 		goto failed_mount_wq;
3729 	} else {
3730 		/* Nojournal mode, all journal mount options are illegal */
3731 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3732 			ext4_msg(sb, KERN_ERR, "can't mount with "
3733 				 "journal_checksum, fs mounted w/o journal");
3734 			goto failed_mount_wq;
3735 		}
3736 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3737 			ext4_msg(sb, KERN_ERR, "can't mount with "
3738 				 "journal_async_commit, fs mounted w/o journal");
3739 			goto failed_mount_wq;
3740 		}
3741 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3742 			ext4_msg(sb, KERN_ERR, "can't mount with "
3743 				 "commit=%lu, fs mounted w/o journal",
3744 				 sbi->s_commit_interval / HZ);
3745 			goto failed_mount_wq;
3746 		}
3747 		if (EXT4_MOUNT_DATA_FLAGS &
3748 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3749 			ext4_msg(sb, KERN_ERR, "can't mount with "
3750 				 "data=, fs mounted w/o journal");
3751 			goto failed_mount_wq;
3752 		}
3753 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3754 		clear_opt(sb, JOURNAL_CHECKSUM);
3755 		clear_opt(sb, DATA_FLAGS);
3756 		sbi->s_journal = NULL;
3757 		needs_recovery = 0;
3758 		goto no_journal;
3759 	}
3760 
3761 	if (ext4_has_feature_64bit(sb) &&
3762 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3763 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3764 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3765 		goto failed_mount_wq;
3766 	}
3767 
3768 	if (!set_journal_csum_feature_set(sb)) {
3769 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3770 			 "feature set");
3771 		goto failed_mount_wq;
3772 	}
3773 
3774 	/* We have now updated the journal if required, so we can
3775 	 * validate the data journaling mode. */
3776 	switch (test_opt(sb, DATA_FLAGS)) {
3777 	case 0:
3778 		/* No mode set, assume a default based on the journal
3779 		 * capabilities: ORDERED_DATA if the journal can
3780 		 * cope, else JOURNAL_DATA
3781 		 */
3782 		if (jbd2_journal_check_available_features
3783 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3784 			set_opt(sb, ORDERED_DATA);
3785 		else
3786 			set_opt(sb, JOURNAL_DATA);
3787 		break;
3788 
3789 	case EXT4_MOUNT_ORDERED_DATA:
3790 	case EXT4_MOUNT_WRITEBACK_DATA:
3791 		if (!jbd2_journal_check_available_features
3792 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3793 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3794 			       "requested data journaling mode");
3795 			goto failed_mount_wq;
3796 		}
3797 	default:
3798 		break;
3799 	}
3800 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3801 
3802 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3803 
3804 no_journal:
3805 	sbi->s_mb_cache = ext4_xattr_create_cache();
3806 	if (!sbi->s_mb_cache) {
3807 		ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3808 		goto failed_mount_wq;
3809 	}
3810 
3811 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3812 	    (blocksize != PAGE_SIZE)) {
3813 		ext4_msg(sb, KERN_ERR,
3814 			 "Unsupported blocksize for fs encryption");
3815 		goto failed_mount_wq;
3816 	}
3817 
3818 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3819 	    !ext4_has_feature_encrypt(sb)) {
3820 		ext4_set_feature_encrypt(sb);
3821 		ext4_commit_super(sb, 1);
3822 	}
3823 
3824 	/*
3825 	 * Get the # of file system overhead blocks from the
3826 	 * superblock if present.
3827 	 */
3828 	if (es->s_overhead_clusters)
3829 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3830 	else {
3831 		err = ext4_calculate_overhead(sb);
3832 		if (err)
3833 			goto failed_mount_wq;
3834 	}
3835 
3836 	/*
3837 	 * The maximum number of concurrent works can be high and
3838 	 * concurrency isn't really necessary.  Limit it to 1.
3839 	 */
3840 	EXT4_SB(sb)->rsv_conversion_wq =
3841 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3842 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
3843 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3844 		ret = -ENOMEM;
3845 		goto failed_mount4;
3846 	}
3847 
3848 	/*
3849 	 * The jbd2_journal_load will have done any necessary log recovery,
3850 	 * so we can safely mount the rest of the filesystem now.
3851 	 */
3852 
3853 	root = ext4_iget(sb, EXT4_ROOT_INO);
3854 	if (IS_ERR(root)) {
3855 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3856 		ret = PTR_ERR(root);
3857 		root = NULL;
3858 		goto failed_mount4;
3859 	}
3860 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3861 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3862 		iput(root);
3863 		goto failed_mount4;
3864 	}
3865 	sb->s_root = d_make_root(root);
3866 	if (!sb->s_root) {
3867 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3868 		ret = -ENOMEM;
3869 		goto failed_mount4;
3870 	}
3871 
3872 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3873 		sb->s_flags |= MS_RDONLY;
3874 
3875 	/* determine the minimum size of new large inodes, if present */
3876 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3877 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3878 						     EXT4_GOOD_OLD_INODE_SIZE;
3879 		if (ext4_has_feature_extra_isize(sb)) {
3880 			if (sbi->s_want_extra_isize <
3881 			    le16_to_cpu(es->s_want_extra_isize))
3882 				sbi->s_want_extra_isize =
3883 					le16_to_cpu(es->s_want_extra_isize);
3884 			if (sbi->s_want_extra_isize <
3885 			    le16_to_cpu(es->s_min_extra_isize))
3886 				sbi->s_want_extra_isize =
3887 					le16_to_cpu(es->s_min_extra_isize);
3888 		}
3889 	}
3890 	/* Check if enough inode space is available */
3891 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3892 							sbi->s_inode_size) {
3893 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3894 						       EXT4_GOOD_OLD_INODE_SIZE;
3895 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
3896 			 "available");
3897 	}
3898 
3899 	ext4_set_resv_clusters(sb);
3900 
3901 	err = ext4_setup_system_zone(sb);
3902 	if (err) {
3903 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
3904 			 "zone (%d)", err);
3905 		goto failed_mount4a;
3906 	}
3907 
3908 	ext4_ext_init(sb);
3909 	err = ext4_mb_init(sb);
3910 	if (err) {
3911 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3912 			 err);
3913 		goto failed_mount5;
3914 	}
3915 
3916 	block = ext4_count_free_clusters(sb);
3917 	ext4_free_blocks_count_set(sbi->s_es,
3918 				   EXT4_C2B(sbi, block));
3919 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
3920 				  GFP_KERNEL);
3921 	if (!err) {
3922 		unsigned long freei = ext4_count_free_inodes(sb);
3923 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
3924 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
3925 					  GFP_KERNEL);
3926 	}
3927 	if (!err)
3928 		err = percpu_counter_init(&sbi->s_dirs_counter,
3929 					  ext4_count_dirs(sb), GFP_KERNEL);
3930 	if (!err)
3931 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
3932 					  GFP_KERNEL);
3933 	if (err) {
3934 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3935 		goto failed_mount6;
3936 	}
3937 
3938 	if (ext4_has_feature_flex_bg(sb))
3939 		if (!ext4_fill_flex_info(sb)) {
3940 			ext4_msg(sb, KERN_ERR,
3941 			       "unable to initialize "
3942 			       "flex_bg meta info!");
3943 			goto failed_mount6;
3944 		}
3945 
3946 	err = ext4_register_li_request(sb, first_not_zeroed);
3947 	if (err)
3948 		goto failed_mount6;
3949 
3950 	err = ext4_register_sysfs(sb);
3951 	if (err)
3952 		goto failed_mount7;
3953 
3954 #ifdef CONFIG_QUOTA
3955 	/* Enable quota usage during mount. */
3956 	if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
3957 		err = ext4_enable_quotas(sb);
3958 		if (err)
3959 			goto failed_mount8;
3960 	}
3961 #endif  /* CONFIG_QUOTA */
3962 
3963 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3964 	ext4_orphan_cleanup(sb, es);
3965 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3966 	if (needs_recovery) {
3967 		ext4_msg(sb, KERN_INFO, "recovery complete");
3968 		ext4_mark_recovery_complete(sb, es);
3969 	}
3970 	if (EXT4_SB(sb)->s_journal) {
3971 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3972 			descr = " journalled data mode";
3973 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3974 			descr = " ordered data mode";
3975 		else
3976 			descr = " writeback data mode";
3977 	} else
3978 		descr = "out journal";
3979 
3980 	if (test_opt(sb, DISCARD)) {
3981 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
3982 		if (!blk_queue_discard(q))
3983 			ext4_msg(sb, KERN_WARNING,
3984 				 "mounting with \"discard\" option, but "
3985 				 "the device does not support discard");
3986 	}
3987 
3988 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
3989 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3990 			 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3991 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3992 
3993 	if (es->s_error_count)
3994 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3995 
3996 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
3997 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
3998 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
3999 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4000 
4001 	kfree(orig_data);
4002 	return 0;
4003 
4004 cantfind_ext4:
4005 	if (!silent)
4006 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4007 	goto failed_mount;
4008 
4009 #ifdef CONFIG_QUOTA
4010 failed_mount8:
4011 	ext4_unregister_sysfs(sb);
4012 #endif
4013 failed_mount7:
4014 	ext4_unregister_li_request(sb);
4015 failed_mount6:
4016 	ext4_mb_release(sb);
4017 	if (sbi->s_flex_groups)
4018 		kvfree(sbi->s_flex_groups);
4019 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4020 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4021 	percpu_counter_destroy(&sbi->s_dirs_counter);
4022 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4023 failed_mount5:
4024 	ext4_ext_release(sb);
4025 	ext4_release_system_zone(sb);
4026 failed_mount4a:
4027 	dput(sb->s_root);
4028 	sb->s_root = NULL;
4029 failed_mount4:
4030 	ext4_msg(sb, KERN_ERR, "mount failed");
4031 	if (EXT4_SB(sb)->rsv_conversion_wq)
4032 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4033 failed_mount_wq:
4034 	if (sbi->s_mb_cache) {
4035 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
4036 		sbi->s_mb_cache = NULL;
4037 	}
4038 	if (sbi->s_journal) {
4039 		jbd2_journal_destroy(sbi->s_journal);
4040 		sbi->s_journal = NULL;
4041 	}
4042 failed_mount3a:
4043 	ext4_es_unregister_shrinker(sbi);
4044 failed_mount3:
4045 	del_timer_sync(&sbi->s_err_report);
4046 	if (sbi->s_mmp_tsk)
4047 		kthread_stop(sbi->s_mmp_tsk);
4048 failed_mount2:
4049 	for (i = 0; i < db_count; i++)
4050 		brelse(sbi->s_group_desc[i]);
4051 	kvfree(sbi->s_group_desc);
4052 failed_mount:
4053 	if (sbi->s_chksum_driver)
4054 		crypto_free_shash(sbi->s_chksum_driver);
4055 #ifdef CONFIG_QUOTA
4056 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4057 		kfree(sbi->s_qf_names[i]);
4058 #endif
4059 	ext4_blkdev_remove(sbi);
4060 	brelse(bh);
4061 out_fail:
4062 	sb->s_fs_info = NULL;
4063 	kfree(sbi->s_blockgroup_lock);
4064 	kfree(sbi);
4065 out_free_orig:
4066 	kfree(orig_data);
4067 	return err ? err : ret;
4068 }
4069 
4070 /*
4071  * Setup any per-fs journal parameters now.  We'll do this both on
4072  * initial mount, once the journal has been initialised but before we've
4073  * done any recovery; and again on any subsequent remount.
4074  */
4075 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4076 {
4077 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4078 
4079 	journal->j_commit_interval = sbi->s_commit_interval;
4080 	journal->j_min_batch_time = sbi->s_min_batch_time;
4081 	journal->j_max_batch_time = sbi->s_max_batch_time;
4082 
4083 	write_lock(&journal->j_state_lock);
4084 	if (test_opt(sb, BARRIER))
4085 		journal->j_flags |= JBD2_BARRIER;
4086 	else
4087 		journal->j_flags &= ~JBD2_BARRIER;
4088 	if (test_opt(sb, DATA_ERR_ABORT))
4089 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4090 	else
4091 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4092 	write_unlock(&journal->j_state_lock);
4093 }
4094 
4095 static journal_t *ext4_get_journal(struct super_block *sb,
4096 				   unsigned int journal_inum)
4097 {
4098 	struct inode *journal_inode;
4099 	journal_t *journal;
4100 
4101 	BUG_ON(!ext4_has_feature_journal(sb));
4102 
4103 	/* First, test for the existence of a valid inode on disk.  Bad
4104 	 * things happen if we iget() an unused inode, as the subsequent
4105 	 * iput() will try to delete it. */
4106 
4107 	journal_inode = ext4_iget(sb, journal_inum);
4108 	if (IS_ERR(journal_inode)) {
4109 		ext4_msg(sb, KERN_ERR, "no journal found");
4110 		return NULL;
4111 	}
4112 	if (!journal_inode->i_nlink) {
4113 		make_bad_inode(journal_inode);
4114 		iput(journal_inode);
4115 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4116 		return NULL;
4117 	}
4118 
4119 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4120 		  journal_inode, journal_inode->i_size);
4121 	if (!S_ISREG(journal_inode->i_mode)) {
4122 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4123 		iput(journal_inode);
4124 		return NULL;
4125 	}
4126 
4127 	journal = jbd2_journal_init_inode(journal_inode);
4128 	if (!journal) {
4129 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4130 		iput(journal_inode);
4131 		return NULL;
4132 	}
4133 	journal->j_private = sb;
4134 	ext4_init_journal_params(sb, journal);
4135 	return journal;
4136 }
4137 
4138 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4139 				       dev_t j_dev)
4140 {
4141 	struct buffer_head *bh;
4142 	journal_t *journal;
4143 	ext4_fsblk_t start;
4144 	ext4_fsblk_t len;
4145 	int hblock, blocksize;
4146 	ext4_fsblk_t sb_block;
4147 	unsigned long offset;
4148 	struct ext4_super_block *es;
4149 	struct block_device *bdev;
4150 
4151 	BUG_ON(!ext4_has_feature_journal(sb));
4152 
4153 	bdev = ext4_blkdev_get(j_dev, sb);
4154 	if (bdev == NULL)
4155 		return NULL;
4156 
4157 	blocksize = sb->s_blocksize;
4158 	hblock = bdev_logical_block_size(bdev);
4159 	if (blocksize < hblock) {
4160 		ext4_msg(sb, KERN_ERR,
4161 			"blocksize too small for journal device");
4162 		goto out_bdev;
4163 	}
4164 
4165 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4166 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4167 	set_blocksize(bdev, blocksize);
4168 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4169 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4170 		       "external journal");
4171 		goto out_bdev;
4172 	}
4173 
4174 	es = (struct ext4_super_block *) (bh->b_data + offset);
4175 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4176 	    !(le32_to_cpu(es->s_feature_incompat) &
4177 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4178 		ext4_msg(sb, KERN_ERR, "external journal has "
4179 					"bad superblock");
4180 		brelse(bh);
4181 		goto out_bdev;
4182 	}
4183 
4184 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4185 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4186 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4187 		ext4_msg(sb, KERN_ERR, "external journal has "
4188 				       "corrupt superblock");
4189 		brelse(bh);
4190 		goto out_bdev;
4191 	}
4192 
4193 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4194 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4195 		brelse(bh);
4196 		goto out_bdev;
4197 	}
4198 
4199 	len = ext4_blocks_count(es);
4200 	start = sb_block + 1;
4201 	brelse(bh);	/* we're done with the superblock */
4202 
4203 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4204 					start, len, blocksize);
4205 	if (!journal) {
4206 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4207 		goto out_bdev;
4208 	}
4209 	journal->j_private = sb;
4210 	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4211 	wait_on_buffer(journal->j_sb_buffer);
4212 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4213 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4214 		goto out_journal;
4215 	}
4216 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4217 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4218 					"user (unsupported) - %d",
4219 			be32_to_cpu(journal->j_superblock->s_nr_users));
4220 		goto out_journal;
4221 	}
4222 	EXT4_SB(sb)->journal_bdev = bdev;
4223 	ext4_init_journal_params(sb, journal);
4224 	return journal;
4225 
4226 out_journal:
4227 	jbd2_journal_destroy(journal);
4228 out_bdev:
4229 	ext4_blkdev_put(bdev);
4230 	return NULL;
4231 }
4232 
4233 static int ext4_load_journal(struct super_block *sb,
4234 			     struct ext4_super_block *es,
4235 			     unsigned long journal_devnum)
4236 {
4237 	journal_t *journal;
4238 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4239 	dev_t journal_dev;
4240 	int err = 0;
4241 	int really_read_only;
4242 
4243 	BUG_ON(!ext4_has_feature_journal(sb));
4244 
4245 	if (journal_devnum &&
4246 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4247 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4248 			"numbers have changed");
4249 		journal_dev = new_decode_dev(journal_devnum);
4250 	} else
4251 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4252 
4253 	really_read_only = bdev_read_only(sb->s_bdev);
4254 
4255 	/*
4256 	 * Are we loading a blank journal or performing recovery after a
4257 	 * crash?  For recovery, we need to check in advance whether we
4258 	 * can get read-write access to the device.
4259 	 */
4260 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4261 		if (sb->s_flags & MS_RDONLY) {
4262 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4263 					"required on readonly filesystem");
4264 			if (really_read_only) {
4265 				ext4_msg(sb, KERN_ERR, "write access "
4266 					"unavailable, cannot proceed");
4267 				return -EROFS;
4268 			}
4269 			ext4_msg(sb, KERN_INFO, "write access will "
4270 			       "be enabled during recovery");
4271 		}
4272 	}
4273 
4274 	if (journal_inum && journal_dev) {
4275 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4276 		       "and inode journals!");
4277 		return -EINVAL;
4278 	}
4279 
4280 	if (journal_inum) {
4281 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4282 			return -EINVAL;
4283 	} else {
4284 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4285 			return -EINVAL;
4286 	}
4287 
4288 	if (!(journal->j_flags & JBD2_BARRIER))
4289 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4290 
4291 	if (!ext4_has_feature_journal_needs_recovery(sb))
4292 		err = jbd2_journal_wipe(journal, !really_read_only);
4293 	if (!err) {
4294 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4295 		if (save)
4296 			memcpy(save, ((char *) es) +
4297 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4298 		err = jbd2_journal_load(journal);
4299 		if (save)
4300 			memcpy(((char *) es) + EXT4_S_ERR_START,
4301 			       save, EXT4_S_ERR_LEN);
4302 		kfree(save);
4303 	}
4304 
4305 	if (err) {
4306 		ext4_msg(sb, KERN_ERR, "error loading journal");
4307 		jbd2_journal_destroy(journal);
4308 		return err;
4309 	}
4310 
4311 	EXT4_SB(sb)->s_journal = journal;
4312 	ext4_clear_journal_err(sb, es);
4313 
4314 	if (!really_read_only && journal_devnum &&
4315 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4316 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4317 
4318 		/* Make sure we flush the recovery flag to disk. */
4319 		ext4_commit_super(sb, 1);
4320 	}
4321 
4322 	return 0;
4323 }
4324 
4325 static int ext4_commit_super(struct super_block *sb, int sync)
4326 {
4327 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4328 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4329 	int error = 0;
4330 
4331 	if (!sbh || block_device_ejected(sb))
4332 		return error;
4333 	if (buffer_write_io_error(sbh)) {
4334 		/*
4335 		 * Oh, dear.  A previous attempt to write the
4336 		 * superblock failed.  This could happen because the
4337 		 * USB device was yanked out.  Or it could happen to
4338 		 * be a transient write error and maybe the block will
4339 		 * be remapped.  Nothing we can do but to retry the
4340 		 * write and hope for the best.
4341 		 */
4342 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4343 		       "superblock detected");
4344 		clear_buffer_write_io_error(sbh);
4345 		set_buffer_uptodate(sbh);
4346 	}
4347 	/*
4348 	 * If the file system is mounted read-only, don't update the
4349 	 * superblock write time.  This avoids updating the superblock
4350 	 * write time when we are mounting the root file system
4351 	 * read/only but we need to replay the journal; at that point,
4352 	 * for people who are east of GMT and who make their clock
4353 	 * tick in localtime for Windows bug-for-bug compatibility,
4354 	 * the clock is set in the future, and this will cause e2fsck
4355 	 * to complain and force a full file system check.
4356 	 */
4357 	if (!(sb->s_flags & MS_RDONLY))
4358 		es->s_wtime = cpu_to_le32(get_seconds());
4359 	if (sb->s_bdev->bd_part)
4360 		es->s_kbytes_written =
4361 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4362 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4363 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4364 	else
4365 		es->s_kbytes_written =
4366 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4367 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4368 		ext4_free_blocks_count_set(es,
4369 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4370 				&EXT4_SB(sb)->s_freeclusters_counter)));
4371 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4372 		es->s_free_inodes_count =
4373 			cpu_to_le32(percpu_counter_sum_positive(
4374 				&EXT4_SB(sb)->s_freeinodes_counter));
4375 	BUFFER_TRACE(sbh, "marking dirty");
4376 	ext4_superblock_csum_set(sb);
4377 	mark_buffer_dirty(sbh);
4378 	if (sync) {
4379 		error = __sync_dirty_buffer(sbh,
4380 			test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4381 		if (error)
4382 			return error;
4383 
4384 		error = buffer_write_io_error(sbh);
4385 		if (error) {
4386 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4387 			       "superblock");
4388 			clear_buffer_write_io_error(sbh);
4389 			set_buffer_uptodate(sbh);
4390 		}
4391 	}
4392 	return error;
4393 }
4394 
4395 /*
4396  * Have we just finished recovery?  If so, and if we are mounting (or
4397  * remounting) the filesystem readonly, then we will end up with a
4398  * consistent fs on disk.  Record that fact.
4399  */
4400 static void ext4_mark_recovery_complete(struct super_block *sb,
4401 					struct ext4_super_block *es)
4402 {
4403 	journal_t *journal = EXT4_SB(sb)->s_journal;
4404 
4405 	if (!ext4_has_feature_journal(sb)) {
4406 		BUG_ON(journal != NULL);
4407 		return;
4408 	}
4409 	jbd2_journal_lock_updates(journal);
4410 	if (jbd2_journal_flush(journal) < 0)
4411 		goto out;
4412 
4413 	if (ext4_has_feature_journal_needs_recovery(sb) &&
4414 	    sb->s_flags & MS_RDONLY) {
4415 		ext4_clear_feature_journal_needs_recovery(sb);
4416 		ext4_commit_super(sb, 1);
4417 	}
4418 
4419 out:
4420 	jbd2_journal_unlock_updates(journal);
4421 }
4422 
4423 /*
4424  * If we are mounting (or read-write remounting) a filesystem whose journal
4425  * has recorded an error from a previous lifetime, move that error to the
4426  * main filesystem now.
4427  */
4428 static void ext4_clear_journal_err(struct super_block *sb,
4429 				   struct ext4_super_block *es)
4430 {
4431 	journal_t *journal;
4432 	int j_errno;
4433 	const char *errstr;
4434 
4435 	BUG_ON(!ext4_has_feature_journal(sb));
4436 
4437 	journal = EXT4_SB(sb)->s_journal;
4438 
4439 	/*
4440 	 * Now check for any error status which may have been recorded in the
4441 	 * journal by a prior ext4_error() or ext4_abort()
4442 	 */
4443 
4444 	j_errno = jbd2_journal_errno(journal);
4445 	if (j_errno) {
4446 		char nbuf[16];
4447 
4448 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4449 		ext4_warning(sb, "Filesystem error recorded "
4450 			     "from previous mount: %s", errstr);
4451 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4452 
4453 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4454 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4455 		ext4_commit_super(sb, 1);
4456 
4457 		jbd2_journal_clear_err(journal);
4458 		jbd2_journal_update_sb_errno(journal);
4459 	}
4460 }
4461 
4462 /*
4463  * Force the running and committing transactions to commit,
4464  * and wait on the commit.
4465  */
4466 int ext4_force_commit(struct super_block *sb)
4467 {
4468 	journal_t *journal;
4469 
4470 	if (sb->s_flags & MS_RDONLY)
4471 		return 0;
4472 
4473 	journal = EXT4_SB(sb)->s_journal;
4474 	return ext4_journal_force_commit(journal);
4475 }
4476 
4477 static int ext4_sync_fs(struct super_block *sb, int wait)
4478 {
4479 	int ret = 0;
4480 	tid_t target;
4481 	bool needs_barrier = false;
4482 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4483 
4484 	trace_ext4_sync_fs(sb, wait);
4485 	flush_workqueue(sbi->rsv_conversion_wq);
4486 	/*
4487 	 * Writeback quota in non-journalled quota case - journalled quota has
4488 	 * no dirty dquots
4489 	 */
4490 	dquot_writeback_dquots(sb, -1);
4491 	/*
4492 	 * Data writeback is possible w/o journal transaction, so barrier must
4493 	 * being sent at the end of the function. But we can skip it if
4494 	 * transaction_commit will do it for us.
4495 	 */
4496 	if (sbi->s_journal) {
4497 		target = jbd2_get_latest_transaction(sbi->s_journal);
4498 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4499 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4500 			needs_barrier = true;
4501 
4502 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4503 			if (wait)
4504 				ret = jbd2_log_wait_commit(sbi->s_journal,
4505 							   target);
4506 		}
4507 	} else if (wait && test_opt(sb, BARRIER))
4508 		needs_barrier = true;
4509 	if (needs_barrier) {
4510 		int err;
4511 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4512 		if (!ret)
4513 			ret = err;
4514 	}
4515 
4516 	return ret;
4517 }
4518 
4519 /*
4520  * LVM calls this function before a (read-only) snapshot is created.  This
4521  * gives us a chance to flush the journal completely and mark the fs clean.
4522  *
4523  * Note that only this function cannot bring a filesystem to be in a clean
4524  * state independently. It relies on upper layer to stop all data & metadata
4525  * modifications.
4526  */
4527 static int ext4_freeze(struct super_block *sb)
4528 {
4529 	int error = 0;
4530 	journal_t *journal;
4531 
4532 	if (sb->s_flags & MS_RDONLY)
4533 		return 0;
4534 
4535 	journal = EXT4_SB(sb)->s_journal;
4536 
4537 	if (journal) {
4538 		/* Now we set up the journal barrier. */
4539 		jbd2_journal_lock_updates(journal);
4540 
4541 		/*
4542 		 * Don't clear the needs_recovery flag if we failed to
4543 		 * flush the journal.
4544 		 */
4545 		error = jbd2_journal_flush(journal);
4546 		if (error < 0)
4547 			goto out;
4548 
4549 		/* Journal blocked and flushed, clear needs_recovery flag. */
4550 		ext4_clear_feature_journal_needs_recovery(sb);
4551 	}
4552 
4553 	error = ext4_commit_super(sb, 1);
4554 out:
4555 	if (journal)
4556 		/* we rely on upper layer to stop further updates */
4557 		jbd2_journal_unlock_updates(journal);
4558 	return error;
4559 }
4560 
4561 /*
4562  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4563  * flag here, even though the filesystem is not technically dirty yet.
4564  */
4565 static int ext4_unfreeze(struct super_block *sb)
4566 {
4567 	if (sb->s_flags & MS_RDONLY)
4568 		return 0;
4569 
4570 	if (EXT4_SB(sb)->s_journal) {
4571 		/* Reset the needs_recovery flag before the fs is unlocked. */
4572 		ext4_set_feature_journal_needs_recovery(sb);
4573 	}
4574 
4575 	ext4_commit_super(sb, 1);
4576 	return 0;
4577 }
4578 
4579 /*
4580  * Structure to save mount options for ext4_remount's benefit
4581  */
4582 struct ext4_mount_options {
4583 	unsigned long s_mount_opt;
4584 	unsigned long s_mount_opt2;
4585 	kuid_t s_resuid;
4586 	kgid_t s_resgid;
4587 	unsigned long s_commit_interval;
4588 	u32 s_min_batch_time, s_max_batch_time;
4589 #ifdef CONFIG_QUOTA
4590 	int s_jquota_fmt;
4591 	char *s_qf_names[EXT4_MAXQUOTAS];
4592 #endif
4593 };
4594 
4595 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4596 {
4597 	struct ext4_super_block *es;
4598 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4599 	unsigned long old_sb_flags;
4600 	struct ext4_mount_options old_opts;
4601 	int enable_quota = 0;
4602 	ext4_group_t g;
4603 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4604 	int err = 0;
4605 #ifdef CONFIG_QUOTA
4606 	int i, j;
4607 #endif
4608 	char *orig_data = kstrdup(data, GFP_KERNEL);
4609 
4610 	/* Store the original options */
4611 	old_sb_flags = sb->s_flags;
4612 	old_opts.s_mount_opt = sbi->s_mount_opt;
4613 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4614 	old_opts.s_resuid = sbi->s_resuid;
4615 	old_opts.s_resgid = sbi->s_resgid;
4616 	old_opts.s_commit_interval = sbi->s_commit_interval;
4617 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4618 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4619 #ifdef CONFIG_QUOTA
4620 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4621 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4622 		if (sbi->s_qf_names[i]) {
4623 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4624 							 GFP_KERNEL);
4625 			if (!old_opts.s_qf_names[i]) {
4626 				for (j = 0; j < i; j++)
4627 					kfree(old_opts.s_qf_names[j]);
4628 				kfree(orig_data);
4629 				return -ENOMEM;
4630 			}
4631 		} else
4632 			old_opts.s_qf_names[i] = NULL;
4633 #endif
4634 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4635 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4636 
4637 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4638 		err = -EINVAL;
4639 		goto restore_opts;
4640 	}
4641 
4642 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4643 	    test_opt(sb, JOURNAL_CHECKSUM)) {
4644 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4645 			 "during remount not supported; ignoring");
4646 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4647 	}
4648 
4649 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4650 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4651 			ext4_msg(sb, KERN_ERR, "can't mount with "
4652 				 "both data=journal and delalloc");
4653 			err = -EINVAL;
4654 			goto restore_opts;
4655 		}
4656 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4657 			ext4_msg(sb, KERN_ERR, "can't mount with "
4658 				 "both data=journal and dioread_nolock");
4659 			err = -EINVAL;
4660 			goto restore_opts;
4661 		}
4662 		if (test_opt(sb, DAX)) {
4663 			ext4_msg(sb, KERN_ERR, "can't mount with "
4664 				 "both data=journal and dax");
4665 			err = -EINVAL;
4666 			goto restore_opts;
4667 		}
4668 	}
4669 
4670 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4671 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4672 			"dax flag with busy inodes while remounting");
4673 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4674 	}
4675 
4676 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4677 		ext4_abort(sb, "Abort forced by user");
4678 
4679 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4680 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4681 
4682 	es = sbi->s_es;
4683 
4684 	if (sbi->s_journal) {
4685 		ext4_init_journal_params(sb, sbi->s_journal);
4686 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4687 	}
4688 
4689 	if (*flags & MS_LAZYTIME)
4690 		sb->s_flags |= MS_LAZYTIME;
4691 
4692 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4693 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4694 			err = -EROFS;
4695 			goto restore_opts;
4696 		}
4697 
4698 		if (*flags & MS_RDONLY) {
4699 			err = sync_filesystem(sb);
4700 			if (err < 0)
4701 				goto restore_opts;
4702 			err = dquot_suspend(sb, -1);
4703 			if (err < 0)
4704 				goto restore_opts;
4705 
4706 			/*
4707 			 * First of all, the unconditional stuff we have to do
4708 			 * to disable replay of the journal when we next remount
4709 			 */
4710 			sb->s_flags |= MS_RDONLY;
4711 
4712 			/*
4713 			 * OK, test if we are remounting a valid rw partition
4714 			 * readonly, and if so set the rdonly flag and then
4715 			 * mark the partition as valid again.
4716 			 */
4717 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4718 			    (sbi->s_mount_state & EXT4_VALID_FS))
4719 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4720 
4721 			if (sbi->s_journal)
4722 				ext4_mark_recovery_complete(sb, es);
4723 		} else {
4724 			/* Make sure we can mount this feature set readwrite */
4725 			if (ext4_has_feature_readonly(sb) ||
4726 			    !ext4_feature_set_ok(sb, 0)) {
4727 				err = -EROFS;
4728 				goto restore_opts;
4729 			}
4730 			/*
4731 			 * Make sure the group descriptor checksums
4732 			 * are sane.  If they aren't, refuse to remount r/w.
4733 			 */
4734 			for (g = 0; g < sbi->s_groups_count; g++) {
4735 				struct ext4_group_desc *gdp =
4736 					ext4_get_group_desc(sb, g, NULL);
4737 
4738 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4739 					ext4_msg(sb, KERN_ERR,
4740 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4741 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4742 					       le16_to_cpu(gdp->bg_checksum));
4743 					err = -EFSBADCRC;
4744 					goto restore_opts;
4745 				}
4746 			}
4747 
4748 			/*
4749 			 * If we have an unprocessed orphan list hanging
4750 			 * around from a previously readonly bdev mount,
4751 			 * require a full umount/remount for now.
4752 			 */
4753 			if (es->s_last_orphan) {
4754 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4755 				       "remount RDWR because of unprocessed "
4756 				       "orphan inode list.  Please "
4757 				       "umount/remount instead");
4758 				err = -EINVAL;
4759 				goto restore_opts;
4760 			}
4761 
4762 			/*
4763 			 * Mounting a RDONLY partition read-write, so reread
4764 			 * and store the current valid flag.  (It may have
4765 			 * been changed by e2fsck since we originally mounted
4766 			 * the partition.)
4767 			 */
4768 			if (sbi->s_journal)
4769 				ext4_clear_journal_err(sb, es);
4770 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4771 			if (!ext4_setup_super(sb, es, 0))
4772 				sb->s_flags &= ~MS_RDONLY;
4773 			if (ext4_has_feature_mmp(sb))
4774 				if (ext4_multi_mount_protect(sb,
4775 						le64_to_cpu(es->s_mmp_block))) {
4776 					err = -EROFS;
4777 					goto restore_opts;
4778 				}
4779 			enable_quota = 1;
4780 		}
4781 	}
4782 
4783 	/*
4784 	 * Reinitialize lazy itable initialization thread based on
4785 	 * current settings
4786 	 */
4787 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4788 		ext4_unregister_li_request(sb);
4789 	else {
4790 		ext4_group_t first_not_zeroed;
4791 		first_not_zeroed = ext4_has_uninit_itable(sb);
4792 		ext4_register_li_request(sb, first_not_zeroed);
4793 	}
4794 
4795 	ext4_setup_system_zone(sb);
4796 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4797 		ext4_commit_super(sb, 1);
4798 
4799 #ifdef CONFIG_QUOTA
4800 	/* Release old quota file names */
4801 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4802 		kfree(old_opts.s_qf_names[i]);
4803 	if (enable_quota) {
4804 		if (sb_any_quota_suspended(sb))
4805 			dquot_resume(sb, -1);
4806 		else if (ext4_has_feature_quota(sb)) {
4807 			err = ext4_enable_quotas(sb);
4808 			if (err)
4809 				goto restore_opts;
4810 		}
4811 	}
4812 #endif
4813 
4814 	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4815 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4816 	kfree(orig_data);
4817 	return 0;
4818 
4819 restore_opts:
4820 	sb->s_flags = old_sb_flags;
4821 	sbi->s_mount_opt = old_opts.s_mount_opt;
4822 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4823 	sbi->s_resuid = old_opts.s_resuid;
4824 	sbi->s_resgid = old_opts.s_resgid;
4825 	sbi->s_commit_interval = old_opts.s_commit_interval;
4826 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4827 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4828 #ifdef CONFIG_QUOTA
4829 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4830 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
4831 		kfree(sbi->s_qf_names[i]);
4832 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4833 	}
4834 #endif
4835 	kfree(orig_data);
4836 	return err;
4837 }
4838 
4839 #ifdef CONFIG_QUOTA
4840 static int ext4_statfs_project(struct super_block *sb,
4841 			       kprojid_t projid, struct kstatfs *buf)
4842 {
4843 	struct kqid qid;
4844 	struct dquot *dquot;
4845 	u64 limit;
4846 	u64 curblock;
4847 
4848 	qid = make_kqid_projid(projid);
4849 	dquot = dqget(sb, qid);
4850 	if (IS_ERR(dquot))
4851 		return PTR_ERR(dquot);
4852 	spin_lock(&dq_data_lock);
4853 
4854 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
4855 		 dquot->dq_dqb.dqb_bsoftlimit :
4856 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
4857 	if (limit && buf->f_blocks > limit) {
4858 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
4859 		buf->f_blocks = limit;
4860 		buf->f_bfree = buf->f_bavail =
4861 			(buf->f_blocks > curblock) ?
4862 			 (buf->f_blocks - curblock) : 0;
4863 	}
4864 
4865 	limit = dquot->dq_dqb.dqb_isoftlimit ?
4866 		dquot->dq_dqb.dqb_isoftlimit :
4867 		dquot->dq_dqb.dqb_ihardlimit;
4868 	if (limit && buf->f_files > limit) {
4869 		buf->f_files = limit;
4870 		buf->f_ffree =
4871 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
4872 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
4873 	}
4874 
4875 	spin_unlock(&dq_data_lock);
4876 	dqput(dquot);
4877 	return 0;
4878 }
4879 #endif
4880 
4881 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4882 {
4883 	struct super_block *sb = dentry->d_sb;
4884 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4885 	struct ext4_super_block *es = sbi->s_es;
4886 	ext4_fsblk_t overhead = 0, resv_blocks;
4887 	u64 fsid;
4888 	s64 bfree;
4889 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4890 
4891 	if (!test_opt(sb, MINIX_DF))
4892 		overhead = sbi->s_overhead;
4893 
4894 	buf->f_type = EXT4_SUPER_MAGIC;
4895 	buf->f_bsize = sb->s_blocksize;
4896 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4897 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4898 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4899 	/* prevent underflow in case that few free space is available */
4900 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4901 	buf->f_bavail = buf->f_bfree -
4902 			(ext4_r_blocks_count(es) + resv_blocks);
4903 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4904 		buf->f_bavail = 0;
4905 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4906 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4907 	buf->f_namelen = EXT4_NAME_LEN;
4908 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4909 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4910 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4911 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4912 
4913 #ifdef CONFIG_QUOTA
4914 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
4915 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
4916 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
4917 #endif
4918 	return 0;
4919 }
4920 
4921 /* Helper function for writing quotas on sync - we need to start transaction
4922  * before quota file is locked for write. Otherwise the are possible deadlocks:
4923  * Process 1                         Process 2
4924  * ext4_create()                     quota_sync()
4925  *   jbd2_journal_start()                  write_dquot()
4926  *   dquot_initialize()                         down(dqio_mutex)
4927  *     down(dqio_mutex)                    jbd2_journal_start()
4928  *
4929  */
4930 
4931 #ifdef CONFIG_QUOTA
4932 
4933 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4934 {
4935 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4936 }
4937 
4938 static int ext4_write_dquot(struct dquot *dquot)
4939 {
4940 	int ret, err;
4941 	handle_t *handle;
4942 	struct inode *inode;
4943 
4944 	inode = dquot_to_inode(dquot);
4945 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4946 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4947 	if (IS_ERR(handle))
4948 		return PTR_ERR(handle);
4949 	ret = dquot_commit(dquot);
4950 	err = ext4_journal_stop(handle);
4951 	if (!ret)
4952 		ret = err;
4953 	return ret;
4954 }
4955 
4956 static int ext4_acquire_dquot(struct dquot *dquot)
4957 {
4958 	int ret, err;
4959 	handle_t *handle;
4960 
4961 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4962 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4963 	if (IS_ERR(handle))
4964 		return PTR_ERR(handle);
4965 	ret = dquot_acquire(dquot);
4966 	err = ext4_journal_stop(handle);
4967 	if (!ret)
4968 		ret = err;
4969 	return ret;
4970 }
4971 
4972 static int ext4_release_dquot(struct dquot *dquot)
4973 {
4974 	int ret, err;
4975 	handle_t *handle;
4976 
4977 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4978 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4979 	if (IS_ERR(handle)) {
4980 		/* Release dquot anyway to avoid endless cycle in dqput() */
4981 		dquot_release(dquot);
4982 		return PTR_ERR(handle);
4983 	}
4984 	ret = dquot_release(dquot);
4985 	err = ext4_journal_stop(handle);
4986 	if (!ret)
4987 		ret = err;
4988 	return ret;
4989 }
4990 
4991 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4992 {
4993 	struct super_block *sb = dquot->dq_sb;
4994 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4995 
4996 	/* Are we journaling quotas? */
4997 	if (ext4_has_feature_quota(sb) ||
4998 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
4999 		dquot_mark_dquot_dirty(dquot);
5000 		return ext4_write_dquot(dquot);
5001 	} else {
5002 		return dquot_mark_dquot_dirty(dquot);
5003 	}
5004 }
5005 
5006 static int ext4_write_info(struct super_block *sb, int type)
5007 {
5008 	int ret, err;
5009 	handle_t *handle;
5010 
5011 	/* Data block + inode block */
5012 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5013 	if (IS_ERR(handle))
5014 		return PTR_ERR(handle);
5015 	ret = dquot_commit_info(sb, type);
5016 	err = ext4_journal_stop(handle);
5017 	if (!ret)
5018 		ret = err;
5019 	return ret;
5020 }
5021 
5022 /*
5023  * Turn on quotas during mount time - we need to find
5024  * the quota file and such...
5025  */
5026 static int ext4_quota_on_mount(struct super_block *sb, int type)
5027 {
5028 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5029 					EXT4_SB(sb)->s_jquota_fmt, type);
5030 }
5031 
5032 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5033 {
5034 	struct ext4_inode_info *ei = EXT4_I(inode);
5035 
5036 	/* The first argument of lockdep_set_subclass has to be
5037 	 * *exactly* the same as the argument to init_rwsem() --- in
5038 	 * this case, in init_once() --- or lockdep gets unhappy
5039 	 * because the name of the lock is set using the
5040 	 * stringification of the argument to init_rwsem().
5041 	 */
5042 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5043 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5044 }
5045 
5046 /*
5047  * Standard function to be called on quota_on
5048  */
5049 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5050 			 struct path *path)
5051 {
5052 	int err;
5053 
5054 	if (!test_opt(sb, QUOTA))
5055 		return -EINVAL;
5056 
5057 	/* Quotafile not on the same filesystem? */
5058 	if (path->dentry->d_sb != sb)
5059 		return -EXDEV;
5060 	/* Journaling quota? */
5061 	if (EXT4_SB(sb)->s_qf_names[type]) {
5062 		/* Quotafile not in fs root? */
5063 		if (path->dentry->d_parent != sb->s_root)
5064 			ext4_msg(sb, KERN_WARNING,
5065 				"Quota file not on filesystem root. "
5066 				"Journaled quota will not work");
5067 	}
5068 
5069 	/*
5070 	 * When we journal data on quota file, we have to flush journal to see
5071 	 * all updates to the file when we bypass pagecache...
5072 	 */
5073 	if (EXT4_SB(sb)->s_journal &&
5074 	    ext4_should_journal_data(d_inode(path->dentry))) {
5075 		/*
5076 		 * We don't need to lock updates but journal_flush() could
5077 		 * otherwise be livelocked...
5078 		 */
5079 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5080 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5081 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5082 		if (err)
5083 			return err;
5084 	}
5085 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5086 	err = dquot_quota_on(sb, type, format_id, path);
5087 	if (err)
5088 		lockdep_set_quota_inode(path->dentry->d_inode,
5089 					     I_DATA_SEM_NORMAL);
5090 	return err;
5091 }
5092 
5093 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5094 			     unsigned int flags)
5095 {
5096 	int err;
5097 	struct inode *qf_inode;
5098 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5099 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5100 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5101 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5102 	};
5103 
5104 	BUG_ON(!ext4_has_feature_quota(sb));
5105 
5106 	if (!qf_inums[type])
5107 		return -EPERM;
5108 
5109 	qf_inode = ext4_iget(sb, qf_inums[type]);
5110 	if (IS_ERR(qf_inode)) {
5111 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5112 		return PTR_ERR(qf_inode);
5113 	}
5114 
5115 	/* Don't account quota for quota files to avoid recursion */
5116 	qf_inode->i_flags |= S_NOQUOTA;
5117 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5118 	err = dquot_enable(qf_inode, type, format_id, flags);
5119 	iput(qf_inode);
5120 	if (err)
5121 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5122 
5123 	return err;
5124 }
5125 
5126 /* Enable usage tracking for all quota types. */
5127 static int ext4_enable_quotas(struct super_block *sb)
5128 {
5129 	int type, err = 0;
5130 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5131 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5132 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5133 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5134 	};
5135 
5136 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5137 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5138 		if (qf_inums[type]) {
5139 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5140 						DQUOT_USAGE_ENABLED);
5141 			if (err) {
5142 				ext4_warning(sb,
5143 					"Failed to enable quota tracking "
5144 					"(type=%d, err=%d). Please run "
5145 					"e2fsck to fix.", type, err);
5146 				return err;
5147 			}
5148 		}
5149 	}
5150 	return 0;
5151 }
5152 
5153 static int ext4_quota_off(struct super_block *sb, int type)
5154 {
5155 	struct inode *inode = sb_dqopt(sb)->files[type];
5156 	handle_t *handle;
5157 
5158 	/* Force all delayed allocation blocks to be allocated.
5159 	 * Caller already holds s_umount sem */
5160 	if (test_opt(sb, DELALLOC))
5161 		sync_filesystem(sb);
5162 
5163 	if (!inode)
5164 		goto out;
5165 
5166 	/* Update modification times of quota files when userspace can
5167 	 * start looking at them */
5168 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5169 	if (IS_ERR(handle))
5170 		goto out;
5171 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5172 	ext4_mark_inode_dirty(handle, inode);
5173 	ext4_journal_stop(handle);
5174 
5175 out:
5176 	return dquot_quota_off(sb, type);
5177 }
5178 
5179 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5180  * acquiring the locks... As quota files are never truncated and quota code
5181  * itself serializes the operations (and no one else should touch the files)
5182  * we don't have to be afraid of races */
5183 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5184 			       size_t len, loff_t off)
5185 {
5186 	struct inode *inode = sb_dqopt(sb)->files[type];
5187 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5188 	int offset = off & (sb->s_blocksize - 1);
5189 	int tocopy;
5190 	size_t toread;
5191 	struct buffer_head *bh;
5192 	loff_t i_size = i_size_read(inode);
5193 
5194 	if (off > i_size)
5195 		return 0;
5196 	if (off+len > i_size)
5197 		len = i_size-off;
5198 	toread = len;
5199 	while (toread > 0) {
5200 		tocopy = sb->s_blocksize - offset < toread ?
5201 				sb->s_blocksize - offset : toread;
5202 		bh = ext4_bread(NULL, inode, blk, 0);
5203 		if (IS_ERR(bh))
5204 			return PTR_ERR(bh);
5205 		if (!bh)	/* A hole? */
5206 			memset(data, 0, tocopy);
5207 		else
5208 			memcpy(data, bh->b_data+offset, tocopy);
5209 		brelse(bh);
5210 		offset = 0;
5211 		toread -= tocopy;
5212 		data += tocopy;
5213 		blk++;
5214 	}
5215 	return len;
5216 }
5217 
5218 /* Write to quotafile (we know the transaction is already started and has
5219  * enough credits) */
5220 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5221 				const char *data, size_t len, loff_t off)
5222 {
5223 	struct inode *inode = sb_dqopt(sb)->files[type];
5224 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5225 	int err, offset = off & (sb->s_blocksize - 1);
5226 	int retries = 0;
5227 	struct buffer_head *bh;
5228 	handle_t *handle = journal_current_handle();
5229 
5230 	if (EXT4_SB(sb)->s_journal && !handle) {
5231 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5232 			" cancelled because transaction is not started",
5233 			(unsigned long long)off, (unsigned long long)len);
5234 		return -EIO;
5235 	}
5236 	/*
5237 	 * Since we account only one data block in transaction credits,
5238 	 * then it is impossible to cross a block boundary.
5239 	 */
5240 	if (sb->s_blocksize - offset < len) {
5241 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5242 			" cancelled because not block aligned",
5243 			(unsigned long long)off, (unsigned long long)len);
5244 		return -EIO;
5245 	}
5246 
5247 	do {
5248 		bh = ext4_bread(handle, inode, blk,
5249 				EXT4_GET_BLOCKS_CREATE |
5250 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5251 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5252 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5253 	if (IS_ERR(bh))
5254 		return PTR_ERR(bh);
5255 	if (!bh)
5256 		goto out;
5257 	BUFFER_TRACE(bh, "get write access");
5258 	err = ext4_journal_get_write_access(handle, bh);
5259 	if (err) {
5260 		brelse(bh);
5261 		return err;
5262 	}
5263 	lock_buffer(bh);
5264 	memcpy(bh->b_data+offset, data, len);
5265 	flush_dcache_page(bh->b_page);
5266 	unlock_buffer(bh);
5267 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5268 	brelse(bh);
5269 out:
5270 	if (inode->i_size < off + len) {
5271 		i_size_write(inode, off + len);
5272 		EXT4_I(inode)->i_disksize = inode->i_size;
5273 		ext4_mark_inode_dirty(handle, inode);
5274 	}
5275 	return len;
5276 }
5277 
5278 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5279 {
5280 	const struct quota_format_ops	*ops;
5281 
5282 	if (!sb_has_quota_loaded(sb, qid->type))
5283 		return -ESRCH;
5284 	ops = sb_dqopt(sb)->ops[qid->type];
5285 	if (!ops || !ops->get_next_id)
5286 		return -ENOSYS;
5287 	return dquot_get_next_id(sb, qid);
5288 }
5289 #endif
5290 
5291 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5292 		       const char *dev_name, void *data)
5293 {
5294 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5295 }
5296 
5297 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5298 static inline void register_as_ext2(void)
5299 {
5300 	int err = register_filesystem(&ext2_fs_type);
5301 	if (err)
5302 		printk(KERN_WARNING
5303 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5304 }
5305 
5306 static inline void unregister_as_ext2(void)
5307 {
5308 	unregister_filesystem(&ext2_fs_type);
5309 }
5310 
5311 static inline int ext2_feature_set_ok(struct super_block *sb)
5312 {
5313 	if (ext4_has_unknown_ext2_incompat_features(sb))
5314 		return 0;
5315 	if (sb->s_flags & MS_RDONLY)
5316 		return 1;
5317 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5318 		return 0;
5319 	return 1;
5320 }
5321 #else
5322 static inline void register_as_ext2(void) { }
5323 static inline void unregister_as_ext2(void) { }
5324 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5325 #endif
5326 
5327 static inline void register_as_ext3(void)
5328 {
5329 	int err = register_filesystem(&ext3_fs_type);
5330 	if (err)
5331 		printk(KERN_WARNING
5332 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5333 }
5334 
5335 static inline void unregister_as_ext3(void)
5336 {
5337 	unregister_filesystem(&ext3_fs_type);
5338 }
5339 
5340 static inline int ext3_feature_set_ok(struct super_block *sb)
5341 {
5342 	if (ext4_has_unknown_ext3_incompat_features(sb))
5343 		return 0;
5344 	if (!ext4_has_feature_journal(sb))
5345 		return 0;
5346 	if (sb->s_flags & MS_RDONLY)
5347 		return 1;
5348 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5349 		return 0;
5350 	return 1;
5351 }
5352 
5353 static struct file_system_type ext4_fs_type = {
5354 	.owner		= THIS_MODULE,
5355 	.name		= "ext4",
5356 	.mount		= ext4_mount,
5357 	.kill_sb	= kill_block_super,
5358 	.fs_flags	= FS_REQUIRES_DEV,
5359 };
5360 MODULE_ALIAS_FS("ext4");
5361 
5362 /* Shared across all ext4 file systems */
5363 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5364 
5365 static int __init ext4_init_fs(void)
5366 {
5367 	int i, err;
5368 
5369 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5370 	ext4_li_info = NULL;
5371 	mutex_init(&ext4_li_mtx);
5372 
5373 	/* Build-time check for flags consistency */
5374 	ext4_check_flag_values();
5375 
5376 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5377 		init_waitqueue_head(&ext4__ioend_wq[i]);
5378 
5379 	err = ext4_init_es();
5380 	if (err)
5381 		return err;
5382 
5383 	err = ext4_init_pageio();
5384 	if (err)
5385 		goto out5;
5386 
5387 	err = ext4_init_system_zone();
5388 	if (err)
5389 		goto out4;
5390 
5391 	err = ext4_init_sysfs();
5392 	if (err)
5393 		goto out3;
5394 
5395 	err = ext4_init_mballoc();
5396 	if (err)
5397 		goto out2;
5398 	err = init_inodecache();
5399 	if (err)
5400 		goto out1;
5401 	register_as_ext3();
5402 	register_as_ext2();
5403 	err = register_filesystem(&ext4_fs_type);
5404 	if (err)
5405 		goto out;
5406 
5407 	return 0;
5408 out:
5409 	unregister_as_ext2();
5410 	unregister_as_ext3();
5411 	destroy_inodecache();
5412 out1:
5413 	ext4_exit_mballoc();
5414 out2:
5415 	ext4_exit_sysfs();
5416 out3:
5417 	ext4_exit_system_zone();
5418 out4:
5419 	ext4_exit_pageio();
5420 out5:
5421 	ext4_exit_es();
5422 
5423 	return err;
5424 }
5425 
5426 static void __exit ext4_exit_fs(void)
5427 {
5428 	ext4_exit_crypto();
5429 	ext4_destroy_lazyinit_thread();
5430 	unregister_as_ext2();
5431 	unregister_as_ext3();
5432 	unregister_filesystem(&ext4_fs_type);
5433 	destroy_inodecache();
5434 	ext4_exit_mballoc();
5435 	ext4_exit_sysfs();
5436 	ext4_exit_system_zone();
5437 	ext4_exit_pageio();
5438 	ext4_exit_es();
5439 }
5440 
5441 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5442 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5443 MODULE_LICENSE("GPL");
5444 module_init(ext4_init_fs)
5445 module_exit(ext4_exit_fs)
5446