xref: /openbmc/linux/fs/ext4/super.c (revision 78700c0a)
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 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
863 	brelse(sbi->s_sbh);
864 #ifdef CONFIG_QUOTA
865 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
866 		kfree(sbi->s_qf_names[i]);
867 #endif
868 
869 	/* Debugging code just in case the in-memory inode orphan list
870 	 * isn't empty.  The on-disk one can be non-empty if we've
871 	 * detected an error and taken the fs readonly, but the
872 	 * in-memory list had better be clean by this point. */
873 	if (!list_empty(&sbi->s_orphan))
874 		dump_orphan_list(sb, sbi);
875 	J_ASSERT(list_empty(&sbi->s_orphan));
876 
877 	sync_blockdev(sb->s_bdev);
878 	invalidate_bdev(sb->s_bdev);
879 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
880 		/*
881 		 * Invalidate the journal device's buffers.  We don't want them
882 		 * floating about in memory - the physical journal device may
883 		 * hotswapped, and it breaks the `ro-after' testing code.
884 		 */
885 		sync_blockdev(sbi->journal_bdev);
886 		invalidate_bdev(sbi->journal_bdev);
887 		ext4_blkdev_remove(sbi);
888 	}
889 	if (sbi->s_mb_cache) {
890 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
891 		sbi->s_mb_cache = NULL;
892 	}
893 	if (sbi->s_mmp_tsk)
894 		kthread_stop(sbi->s_mmp_tsk);
895 	sb->s_fs_info = NULL;
896 	/*
897 	 * Now that we are completely done shutting down the
898 	 * superblock, we need to actually destroy the kobject.
899 	 */
900 	kobject_put(&sbi->s_kobj);
901 	wait_for_completion(&sbi->s_kobj_unregister);
902 	if (sbi->s_chksum_driver)
903 		crypto_free_shash(sbi->s_chksum_driver);
904 	kfree(sbi->s_blockgroup_lock);
905 	kfree(sbi);
906 }
907 
908 static struct kmem_cache *ext4_inode_cachep;
909 
910 /*
911  * Called inside transaction, so use GFP_NOFS
912  */
913 static struct inode *ext4_alloc_inode(struct super_block *sb)
914 {
915 	struct ext4_inode_info *ei;
916 
917 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
918 	if (!ei)
919 		return NULL;
920 
921 	ei->vfs_inode.i_version = 1;
922 	spin_lock_init(&ei->i_raw_lock);
923 	INIT_LIST_HEAD(&ei->i_prealloc_list);
924 	spin_lock_init(&ei->i_prealloc_lock);
925 	ext4_es_init_tree(&ei->i_es_tree);
926 	rwlock_init(&ei->i_es_lock);
927 	INIT_LIST_HEAD(&ei->i_es_list);
928 	ei->i_es_all_nr = 0;
929 	ei->i_es_shk_nr = 0;
930 	ei->i_es_shrink_lblk = 0;
931 	ei->i_reserved_data_blocks = 0;
932 	ei->i_reserved_meta_blocks = 0;
933 	ei->i_allocated_meta_blocks = 0;
934 	ei->i_da_metadata_calc_len = 0;
935 	ei->i_da_metadata_calc_last_lblock = 0;
936 	spin_lock_init(&(ei->i_block_reservation_lock));
937 #ifdef CONFIG_QUOTA
938 	ei->i_reserved_quota = 0;
939 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
940 #endif
941 	ei->jinode = NULL;
942 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
943 	spin_lock_init(&ei->i_completed_io_lock);
944 	ei->i_sync_tid = 0;
945 	ei->i_datasync_tid = 0;
946 	atomic_set(&ei->i_unwritten, 0);
947 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
948 #ifdef CONFIG_EXT4_FS_ENCRYPTION
949 	ei->i_crypt_info = NULL;
950 #endif
951 	return &ei->vfs_inode;
952 }
953 
954 static int ext4_drop_inode(struct inode *inode)
955 {
956 	int drop = generic_drop_inode(inode);
957 
958 	trace_ext4_drop_inode(inode, drop);
959 	return drop;
960 }
961 
962 static void ext4_i_callback(struct rcu_head *head)
963 {
964 	struct inode *inode = container_of(head, struct inode, i_rcu);
965 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
966 }
967 
968 static void ext4_destroy_inode(struct inode *inode)
969 {
970 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
971 		ext4_msg(inode->i_sb, KERN_ERR,
972 			 "Inode %lu (%p): orphan list check failed!",
973 			 inode->i_ino, EXT4_I(inode));
974 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
975 				EXT4_I(inode), sizeof(struct ext4_inode_info),
976 				true);
977 		dump_stack();
978 	}
979 	call_rcu(&inode->i_rcu, ext4_i_callback);
980 }
981 
982 static void init_once(void *foo)
983 {
984 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
985 
986 	INIT_LIST_HEAD(&ei->i_orphan);
987 	init_rwsem(&ei->xattr_sem);
988 	init_rwsem(&ei->i_data_sem);
989 	init_rwsem(&ei->i_mmap_sem);
990 	inode_init_once(&ei->vfs_inode);
991 }
992 
993 static int __init init_inodecache(void)
994 {
995 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
996 					     sizeof(struct ext4_inode_info),
997 					     0, (SLAB_RECLAIM_ACCOUNT|
998 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
999 					     init_once);
1000 	if (ext4_inode_cachep == NULL)
1001 		return -ENOMEM;
1002 	return 0;
1003 }
1004 
1005 static void destroy_inodecache(void)
1006 {
1007 	/*
1008 	 * Make sure all delayed rcu free inodes are flushed before we
1009 	 * destroy cache.
1010 	 */
1011 	rcu_barrier();
1012 	kmem_cache_destroy(ext4_inode_cachep);
1013 }
1014 
1015 void ext4_clear_inode(struct inode *inode)
1016 {
1017 	invalidate_inode_buffers(inode);
1018 	clear_inode(inode);
1019 	dquot_drop(inode);
1020 	ext4_discard_preallocations(inode);
1021 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1022 	if (EXT4_I(inode)->jinode) {
1023 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1024 					       EXT4_I(inode)->jinode);
1025 		jbd2_free_inode(EXT4_I(inode)->jinode);
1026 		EXT4_I(inode)->jinode = NULL;
1027 	}
1028 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1029 	if (EXT4_I(inode)->i_crypt_info)
1030 		ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info);
1031 #endif
1032 }
1033 
1034 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1035 					u64 ino, u32 generation)
1036 {
1037 	struct inode *inode;
1038 
1039 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1040 		return ERR_PTR(-ESTALE);
1041 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1042 		return ERR_PTR(-ESTALE);
1043 
1044 	/* iget isn't really right if the inode is currently unallocated!!
1045 	 *
1046 	 * ext4_read_inode will return a bad_inode if the inode had been
1047 	 * deleted, so we should be safe.
1048 	 *
1049 	 * Currently we don't know the generation for parent directory, so
1050 	 * a generation of 0 means "accept any"
1051 	 */
1052 	inode = ext4_iget_normal(sb, ino);
1053 	if (IS_ERR(inode))
1054 		return ERR_CAST(inode);
1055 	if (generation && inode->i_generation != generation) {
1056 		iput(inode);
1057 		return ERR_PTR(-ESTALE);
1058 	}
1059 
1060 	return inode;
1061 }
1062 
1063 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1064 					int fh_len, int fh_type)
1065 {
1066 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1067 				    ext4_nfs_get_inode);
1068 }
1069 
1070 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1071 					int fh_len, int fh_type)
1072 {
1073 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1074 				    ext4_nfs_get_inode);
1075 }
1076 
1077 /*
1078  * Try to release metadata pages (indirect blocks, directories) which are
1079  * mapped via the block device.  Since these pages could have journal heads
1080  * which would prevent try_to_free_buffers() from freeing them, we must use
1081  * jbd2 layer's try_to_free_buffers() function to release them.
1082  */
1083 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1084 				 gfp_t wait)
1085 {
1086 	journal_t *journal = EXT4_SB(sb)->s_journal;
1087 
1088 	WARN_ON(PageChecked(page));
1089 	if (!page_has_buffers(page))
1090 		return 0;
1091 	if (journal)
1092 		return jbd2_journal_try_to_free_buffers(journal, page,
1093 						wait & ~__GFP_DIRECT_RECLAIM);
1094 	return try_to_free_buffers(page);
1095 }
1096 
1097 #ifdef CONFIG_QUOTA
1098 static char *quotatypes[] = INITQFNAMES;
1099 #define QTYPE2NAME(t) (quotatypes[t])
1100 
1101 static int ext4_write_dquot(struct dquot *dquot);
1102 static int ext4_acquire_dquot(struct dquot *dquot);
1103 static int ext4_release_dquot(struct dquot *dquot);
1104 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1105 static int ext4_write_info(struct super_block *sb, int type);
1106 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1107 			 struct path *path);
1108 static int ext4_quota_off(struct super_block *sb, int type);
1109 static int ext4_quota_on_mount(struct super_block *sb, int type);
1110 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1111 			       size_t len, loff_t off);
1112 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1113 				const char *data, size_t len, loff_t off);
1114 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1115 			     unsigned int flags);
1116 static int ext4_enable_quotas(struct super_block *sb);
1117 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1118 
1119 static struct dquot **ext4_get_dquots(struct inode *inode)
1120 {
1121 	return EXT4_I(inode)->i_dquot;
1122 }
1123 
1124 static const struct dquot_operations ext4_quota_operations = {
1125 	.get_reserved_space = ext4_get_reserved_space,
1126 	.write_dquot	= ext4_write_dquot,
1127 	.acquire_dquot	= ext4_acquire_dquot,
1128 	.release_dquot	= ext4_release_dquot,
1129 	.mark_dirty	= ext4_mark_dquot_dirty,
1130 	.write_info	= ext4_write_info,
1131 	.alloc_dquot	= dquot_alloc,
1132 	.destroy_dquot	= dquot_destroy,
1133 	.get_projid	= ext4_get_projid,
1134 	.get_next_id	= ext4_get_next_id,
1135 };
1136 
1137 static const struct quotactl_ops ext4_qctl_operations = {
1138 	.quota_on	= ext4_quota_on,
1139 	.quota_off	= ext4_quota_off,
1140 	.quota_sync	= dquot_quota_sync,
1141 	.get_state	= dquot_get_state,
1142 	.set_info	= dquot_set_dqinfo,
1143 	.get_dqblk	= dquot_get_dqblk,
1144 	.set_dqblk	= dquot_set_dqblk,
1145 	.get_nextdqblk	= dquot_get_next_dqblk,
1146 };
1147 #endif
1148 
1149 static const struct super_operations ext4_sops = {
1150 	.alloc_inode	= ext4_alloc_inode,
1151 	.destroy_inode	= ext4_destroy_inode,
1152 	.write_inode	= ext4_write_inode,
1153 	.dirty_inode	= ext4_dirty_inode,
1154 	.drop_inode	= ext4_drop_inode,
1155 	.evict_inode	= ext4_evict_inode,
1156 	.put_super	= ext4_put_super,
1157 	.sync_fs	= ext4_sync_fs,
1158 	.freeze_fs	= ext4_freeze,
1159 	.unfreeze_fs	= ext4_unfreeze,
1160 	.statfs		= ext4_statfs,
1161 	.remount_fs	= ext4_remount,
1162 	.show_options	= ext4_show_options,
1163 #ifdef CONFIG_QUOTA
1164 	.quota_read	= ext4_quota_read,
1165 	.quota_write	= ext4_quota_write,
1166 	.get_dquots	= ext4_get_dquots,
1167 #endif
1168 	.bdev_try_to_free_page = bdev_try_to_free_page,
1169 };
1170 
1171 static const struct export_operations ext4_export_ops = {
1172 	.fh_to_dentry = ext4_fh_to_dentry,
1173 	.fh_to_parent = ext4_fh_to_parent,
1174 	.get_parent = ext4_get_parent,
1175 };
1176 
1177 enum {
1178 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1179 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1180 	Opt_nouid32, Opt_debug, Opt_removed,
1181 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1182 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1183 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1184 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1185 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1186 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1187 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1188 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1189 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1190 	Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1191 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1192 	Opt_lazytime, Opt_nolazytime,
1193 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1194 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1195 	Opt_dioread_nolock, Opt_dioread_lock,
1196 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1197 	Opt_max_dir_size_kb, Opt_nojournal_checksum,
1198 };
1199 
1200 static const match_table_t tokens = {
1201 	{Opt_bsd_df, "bsddf"},
1202 	{Opt_minix_df, "minixdf"},
1203 	{Opt_grpid, "grpid"},
1204 	{Opt_grpid, "bsdgroups"},
1205 	{Opt_nogrpid, "nogrpid"},
1206 	{Opt_nogrpid, "sysvgroups"},
1207 	{Opt_resgid, "resgid=%u"},
1208 	{Opt_resuid, "resuid=%u"},
1209 	{Opt_sb, "sb=%u"},
1210 	{Opt_err_cont, "errors=continue"},
1211 	{Opt_err_panic, "errors=panic"},
1212 	{Opt_err_ro, "errors=remount-ro"},
1213 	{Opt_nouid32, "nouid32"},
1214 	{Opt_debug, "debug"},
1215 	{Opt_removed, "oldalloc"},
1216 	{Opt_removed, "orlov"},
1217 	{Opt_user_xattr, "user_xattr"},
1218 	{Opt_nouser_xattr, "nouser_xattr"},
1219 	{Opt_acl, "acl"},
1220 	{Opt_noacl, "noacl"},
1221 	{Opt_noload, "norecovery"},
1222 	{Opt_noload, "noload"},
1223 	{Opt_removed, "nobh"},
1224 	{Opt_removed, "bh"},
1225 	{Opt_commit, "commit=%u"},
1226 	{Opt_min_batch_time, "min_batch_time=%u"},
1227 	{Opt_max_batch_time, "max_batch_time=%u"},
1228 	{Opt_journal_dev, "journal_dev=%u"},
1229 	{Opt_journal_path, "journal_path=%s"},
1230 	{Opt_journal_checksum, "journal_checksum"},
1231 	{Opt_nojournal_checksum, "nojournal_checksum"},
1232 	{Opt_journal_async_commit, "journal_async_commit"},
1233 	{Opt_abort, "abort"},
1234 	{Opt_data_journal, "data=journal"},
1235 	{Opt_data_ordered, "data=ordered"},
1236 	{Opt_data_writeback, "data=writeback"},
1237 	{Opt_data_err_abort, "data_err=abort"},
1238 	{Opt_data_err_ignore, "data_err=ignore"},
1239 	{Opt_offusrjquota, "usrjquota="},
1240 	{Opt_usrjquota, "usrjquota=%s"},
1241 	{Opt_offgrpjquota, "grpjquota="},
1242 	{Opt_grpjquota, "grpjquota=%s"},
1243 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1244 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1245 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1246 	{Opt_grpquota, "grpquota"},
1247 	{Opt_noquota, "noquota"},
1248 	{Opt_quota, "quota"},
1249 	{Opt_usrquota, "usrquota"},
1250 	{Opt_barrier, "barrier=%u"},
1251 	{Opt_barrier, "barrier"},
1252 	{Opt_nobarrier, "nobarrier"},
1253 	{Opt_i_version, "i_version"},
1254 	{Opt_dax, "dax"},
1255 	{Opt_stripe, "stripe=%u"},
1256 	{Opt_delalloc, "delalloc"},
1257 	{Opt_lazytime, "lazytime"},
1258 	{Opt_nolazytime, "nolazytime"},
1259 	{Opt_nodelalloc, "nodelalloc"},
1260 	{Opt_removed, "mblk_io_submit"},
1261 	{Opt_removed, "nomblk_io_submit"},
1262 	{Opt_block_validity, "block_validity"},
1263 	{Opt_noblock_validity, "noblock_validity"},
1264 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1265 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1266 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1267 	{Opt_auto_da_alloc, "auto_da_alloc"},
1268 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1269 	{Opt_dioread_nolock, "dioread_nolock"},
1270 	{Opt_dioread_lock, "dioread_lock"},
1271 	{Opt_discard, "discard"},
1272 	{Opt_nodiscard, "nodiscard"},
1273 	{Opt_init_itable, "init_itable=%u"},
1274 	{Opt_init_itable, "init_itable"},
1275 	{Opt_noinit_itable, "noinit_itable"},
1276 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1277 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1278 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1279 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1280 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1281 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1282 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1283 	{Opt_err, NULL},
1284 };
1285 
1286 static ext4_fsblk_t get_sb_block(void **data)
1287 {
1288 	ext4_fsblk_t	sb_block;
1289 	char		*options = (char *) *data;
1290 
1291 	if (!options || strncmp(options, "sb=", 3) != 0)
1292 		return 1;	/* Default location */
1293 
1294 	options += 3;
1295 	/* TODO: use simple_strtoll with >32bit ext4 */
1296 	sb_block = simple_strtoul(options, &options, 0);
1297 	if (*options && *options != ',') {
1298 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1299 		       (char *) *data);
1300 		return 1;
1301 	}
1302 	if (*options == ',')
1303 		options++;
1304 	*data = (void *) options;
1305 
1306 	return sb_block;
1307 }
1308 
1309 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1310 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1311 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1312 
1313 #ifdef CONFIG_QUOTA
1314 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1315 {
1316 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1317 	char *qname;
1318 	int ret = -1;
1319 
1320 	if (sb_any_quota_loaded(sb) &&
1321 		!sbi->s_qf_names[qtype]) {
1322 		ext4_msg(sb, KERN_ERR,
1323 			"Cannot change journaled "
1324 			"quota options when quota turned on");
1325 		return -1;
1326 	}
1327 	if (ext4_has_feature_quota(sb)) {
1328 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1329 			 "ignored when QUOTA feature is enabled");
1330 		return 1;
1331 	}
1332 	qname = match_strdup(args);
1333 	if (!qname) {
1334 		ext4_msg(sb, KERN_ERR,
1335 			"Not enough memory for storing quotafile name");
1336 		return -1;
1337 	}
1338 	if (sbi->s_qf_names[qtype]) {
1339 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1340 			ret = 1;
1341 		else
1342 			ext4_msg(sb, KERN_ERR,
1343 				 "%s quota file already specified",
1344 				 QTYPE2NAME(qtype));
1345 		goto errout;
1346 	}
1347 	if (strchr(qname, '/')) {
1348 		ext4_msg(sb, KERN_ERR,
1349 			"quotafile must be on filesystem root");
1350 		goto errout;
1351 	}
1352 	sbi->s_qf_names[qtype] = qname;
1353 	set_opt(sb, QUOTA);
1354 	return 1;
1355 errout:
1356 	kfree(qname);
1357 	return ret;
1358 }
1359 
1360 static int clear_qf_name(struct super_block *sb, int qtype)
1361 {
1362 
1363 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1364 
1365 	if (sb_any_quota_loaded(sb) &&
1366 		sbi->s_qf_names[qtype]) {
1367 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1368 			" when quota turned on");
1369 		return -1;
1370 	}
1371 	kfree(sbi->s_qf_names[qtype]);
1372 	sbi->s_qf_names[qtype] = NULL;
1373 	return 1;
1374 }
1375 #endif
1376 
1377 #define MOPT_SET	0x0001
1378 #define MOPT_CLEAR	0x0002
1379 #define MOPT_NOSUPPORT	0x0004
1380 #define MOPT_EXPLICIT	0x0008
1381 #define MOPT_CLEAR_ERR	0x0010
1382 #define MOPT_GTE0	0x0020
1383 #ifdef CONFIG_QUOTA
1384 #define MOPT_Q		0
1385 #define MOPT_QFMT	0x0040
1386 #else
1387 #define MOPT_Q		MOPT_NOSUPPORT
1388 #define MOPT_QFMT	MOPT_NOSUPPORT
1389 #endif
1390 #define MOPT_DATAJ	0x0080
1391 #define MOPT_NO_EXT2	0x0100
1392 #define MOPT_NO_EXT3	0x0200
1393 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1394 #define MOPT_STRING	0x0400
1395 
1396 static const struct mount_opts {
1397 	int	token;
1398 	int	mount_opt;
1399 	int	flags;
1400 } ext4_mount_opts[] = {
1401 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1402 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1403 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1404 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1405 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1406 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1407 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1408 	 MOPT_EXT4_ONLY | MOPT_SET},
1409 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1410 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1411 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1412 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1413 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1414 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1415 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1416 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1417 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1418 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1419 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1420 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1421 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1422 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1423 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1424 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1425 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1426 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1427 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1428 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1429 	 MOPT_NO_EXT2},
1430 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1431 	 MOPT_NO_EXT2},
1432 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1433 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1434 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1435 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1436 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1437 	{Opt_commit, 0, MOPT_GTE0},
1438 	{Opt_max_batch_time, 0, MOPT_GTE0},
1439 	{Opt_min_batch_time, 0, MOPT_GTE0},
1440 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1441 	{Opt_init_itable, 0, MOPT_GTE0},
1442 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1443 	{Opt_stripe, 0, MOPT_GTE0},
1444 	{Opt_resuid, 0, MOPT_GTE0},
1445 	{Opt_resgid, 0, MOPT_GTE0},
1446 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1447 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1448 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1449 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1450 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1451 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1452 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1453 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1454 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1455 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1456 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1457 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1458 #else
1459 	{Opt_acl, 0, MOPT_NOSUPPORT},
1460 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1461 #endif
1462 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1463 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1464 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1465 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1466 							MOPT_SET | MOPT_Q},
1467 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1468 							MOPT_SET | MOPT_Q},
1469 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1470 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1471 	{Opt_usrjquota, 0, MOPT_Q},
1472 	{Opt_grpjquota, 0, MOPT_Q},
1473 	{Opt_offusrjquota, 0, MOPT_Q},
1474 	{Opt_offgrpjquota, 0, MOPT_Q},
1475 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1476 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1477 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1478 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1479 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1480 	{Opt_err, 0, 0}
1481 };
1482 
1483 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1484 			    substring_t *args, unsigned long *journal_devnum,
1485 			    unsigned int *journal_ioprio, int is_remount)
1486 {
1487 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1488 	const struct mount_opts *m;
1489 	kuid_t uid;
1490 	kgid_t gid;
1491 	int arg = 0;
1492 
1493 #ifdef CONFIG_QUOTA
1494 	if (token == Opt_usrjquota)
1495 		return set_qf_name(sb, USRQUOTA, &args[0]);
1496 	else if (token == Opt_grpjquota)
1497 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1498 	else if (token == Opt_offusrjquota)
1499 		return clear_qf_name(sb, USRQUOTA);
1500 	else if (token == Opt_offgrpjquota)
1501 		return clear_qf_name(sb, GRPQUOTA);
1502 #endif
1503 	switch (token) {
1504 	case Opt_noacl:
1505 	case Opt_nouser_xattr:
1506 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1507 		break;
1508 	case Opt_sb:
1509 		return 1;	/* handled by get_sb_block() */
1510 	case Opt_removed:
1511 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1512 		return 1;
1513 	case Opt_abort:
1514 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1515 		return 1;
1516 	case Opt_i_version:
1517 		sb->s_flags |= MS_I_VERSION;
1518 		return 1;
1519 	case Opt_lazytime:
1520 		sb->s_flags |= MS_LAZYTIME;
1521 		return 1;
1522 	case Opt_nolazytime:
1523 		sb->s_flags &= ~MS_LAZYTIME;
1524 		return 1;
1525 	}
1526 
1527 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1528 		if (token == m->token)
1529 			break;
1530 
1531 	if (m->token == Opt_err) {
1532 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1533 			 "or missing value", opt);
1534 		return -1;
1535 	}
1536 
1537 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1538 		ext4_msg(sb, KERN_ERR,
1539 			 "Mount option \"%s\" incompatible with ext2", opt);
1540 		return -1;
1541 	}
1542 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1543 		ext4_msg(sb, KERN_ERR,
1544 			 "Mount option \"%s\" incompatible with ext3", opt);
1545 		return -1;
1546 	}
1547 
1548 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1549 		return -1;
1550 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1551 		return -1;
1552 	if (m->flags & MOPT_EXPLICIT) {
1553 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1554 			set_opt2(sb, EXPLICIT_DELALLOC);
1555 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1556 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1557 		} else
1558 			return -1;
1559 	}
1560 	if (m->flags & MOPT_CLEAR_ERR)
1561 		clear_opt(sb, ERRORS_MASK);
1562 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1563 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1564 			 "options when quota turned on");
1565 		return -1;
1566 	}
1567 
1568 	if (m->flags & MOPT_NOSUPPORT) {
1569 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1570 	} else if (token == Opt_commit) {
1571 		if (arg == 0)
1572 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1573 		sbi->s_commit_interval = HZ * arg;
1574 	} else if (token == Opt_max_batch_time) {
1575 		sbi->s_max_batch_time = arg;
1576 	} else if (token == Opt_min_batch_time) {
1577 		sbi->s_min_batch_time = arg;
1578 	} else if (token == Opt_inode_readahead_blks) {
1579 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1580 			ext4_msg(sb, KERN_ERR,
1581 				 "EXT4-fs: inode_readahead_blks must be "
1582 				 "0 or a power of 2 smaller than 2^31");
1583 			return -1;
1584 		}
1585 		sbi->s_inode_readahead_blks = arg;
1586 	} else if (token == Opt_init_itable) {
1587 		set_opt(sb, INIT_INODE_TABLE);
1588 		if (!args->from)
1589 			arg = EXT4_DEF_LI_WAIT_MULT;
1590 		sbi->s_li_wait_mult = arg;
1591 	} else if (token == Opt_max_dir_size_kb) {
1592 		sbi->s_max_dir_size_kb = arg;
1593 	} else if (token == Opt_stripe) {
1594 		sbi->s_stripe = arg;
1595 	} else if (token == Opt_resuid) {
1596 		uid = make_kuid(current_user_ns(), arg);
1597 		if (!uid_valid(uid)) {
1598 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1599 			return -1;
1600 		}
1601 		sbi->s_resuid = uid;
1602 	} else if (token == Opt_resgid) {
1603 		gid = make_kgid(current_user_ns(), arg);
1604 		if (!gid_valid(gid)) {
1605 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1606 			return -1;
1607 		}
1608 		sbi->s_resgid = gid;
1609 	} else if (token == Opt_journal_dev) {
1610 		if (is_remount) {
1611 			ext4_msg(sb, KERN_ERR,
1612 				 "Cannot specify journal on remount");
1613 			return -1;
1614 		}
1615 		*journal_devnum = arg;
1616 	} else if (token == Opt_journal_path) {
1617 		char *journal_path;
1618 		struct inode *journal_inode;
1619 		struct path path;
1620 		int error;
1621 
1622 		if (is_remount) {
1623 			ext4_msg(sb, KERN_ERR,
1624 				 "Cannot specify journal on remount");
1625 			return -1;
1626 		}
1627 		journal_path = match_strdup(&args[0]);
1628 		if (!journal_path) {
1629 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1630 				"journal device string");
1631 			return -1;
1632 		}
1633 
1634 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1635 		if (error) {
1636 			ext4_msg(sb, KERN_ERR, "error: could not find "
1637 				"journal device path: error %d", error);
1638 			kfree(journal_path);
1639 			return -1;
1640 		}
1641 
1642 		journal_inode = d_inode(path.dentry);
1643 		if (!S_ISBLK(journal_inode->i_mode)) {
1644 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1645 				"is not a block device", journal_path);
1646 			path_put(&path);
1647 			kfree(journal_path);
1648 			return -1;
1649 		}
1650 
1651 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1652 		path_put(&path);
1653 		kfree(journal_path);
1654 	} else if (token == Opt_journal_ioprio) {
1655 		if (arg > 7) {
1656 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1657 				 " (must be 0-7)");
1658 			return -1;
1659 		}
1660 		*journal_ioprio =
1661 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1662 	} else if (token == Opt_test_dummy_encryption) {
1663 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1664 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1665 		ext4_msg(sb, KERN_WARNING,
1666 			 "Test dummy encryption mode enabled");
1667 #else
1668 		ext4_msg(sb, KERN_WARNING,
1669 			 "Test dummy encryption mount option ignored");
1670 #endif
1671 	} else if (m->flags & MOPT_DATAJ) {
1672 		if (is_remount) {
1673 			if (!sbi->s_journal)
1674 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1675 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1676 				ext4_msg(sb, KERN_ERR,
1677 					 "Cannot change data mode on remount");
1678 				return -1;
1679 			}
1680 		} else {
1681 			clear_opt(sb, DATA_FLAGS);
1682 			sbi->s_mount_opt |= m->mount_opt;
1683 		}
1684 #ifdef CONFIG_QUOTA
1685 	} else if (m->flags & MOPT_QFMT) {
1686 		if (sb_any_quota_loaded(sb) &&
1687 		    sbi->s_jquota_fmt != m->mount_opt) {
1688 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1689 				 "quota options when quota turned on");
1690 			return -1;
1691 		}
1692 		if (ext4_has_feature_quota(sb)) {
1693 			ext4_msg(sb, KERN_INFO,
1694 				 "Quota format mount options ignored "
1695 				 "when QUOTA feature is enabled");
1696 			return 1;
1697 		}
1698 		sbi->s_jquota_fmt = m->mount_opt;
1699 #endif
1700 	} else if (token == Opt_dax) {
1701 #ifdef CONFIG_FS_DAX
1702 		ext4_msg(sb, KERN_WARNING,
1703 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1704 			sbi->s_mount_opt |= m->mount_opt;
1705 #else
1706 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1707 		return -1;
1708 #endif
1709 	} else if (token == Opt_data_err_abort) {
1710 		sbi->s_mount_opt |= m->mount_opt;
1711 	} else if (token == Opt_data_err_ignore) {
1712 		sbi->s_mount_opt &= ~m->mount_opt;
1713 	} else {
1714 		if (!args->from)
1715 			arg = 1;
1716 		if (m->flags & MOPT_CLEAR)
1717 			arg = !arg;
1718 		else if (unlikely(!(m->flags & MOPT_SET))) {
1719 			ext4_msg(sb, KERN_WARNING,
1720 				 "buggy handling of option %s", opt);
1721 			WARN_ON(1);
1722 			return -1;
1723 		}
1724 		if (arg != 0)
1725 			sbi->s_mount_opt |= m->mount_opt;
1726 		else
1727 			sbi->s_mount_opt &= ~m->mount_opt;
1728 	}
1729 	return 1;
1730 }
1731 
1732 static int parse_options(char *options, struct super_block *sb,
1733 			 unsigned long *journal_devnum,
1734 			 unsigned int *journal_ioprio,
1735 			 int is_remount)
1736 {
1737 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1738 	char *p;
1739 	substring_t args[MAX_OPT_ARGS];
1740 	int token;
1741 
1742 	if (!options)
1743 		return 1;
1744 
1745 	while ((p = strsep(&options, ",")) != NULL) {
1746 		if (!*p)
1747 			continue;
1748 		/*
1749 		 * Initialize args struct so we know whether arg was
1750 		 * found; some options take optional arguments.
1751 		 */
1752 		args[0].to = args[0].from = NULL;
1753 		token = match_token(p, tokens, args);
1754 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1755 				     journal_ioprio, is_remount) < 0)
1756 			return 0;
1757 	}
1758 #ifdef CONFIG_QUOTA
1759 	if (ext4_has_feature_quota(sb) &&
1760 	    (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1761 		ext4_msg(sb, KERN_INFO, "Quota feature enabled, usrquota and grpquota "
1762 			 "mount options ignored.");
1763 		clear_opt(sb, USRQUOTA);
1764 		clear_opt(sb, GRPQUOTA);
1765 	} else if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1766 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1767 			clear_opt(sb, USRQUOTA);
1768 
1769 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1770 			clear_opt(sb, GRPQUOTA);
1771 
1772 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1773 			ext4_msg(sb, KERN_ERR, "old and new quota "
1774 					"format mixing");
1775 			return 0;
1776 		}
1777 
1778 		if (!sbi->s_jquota_fmt) {
1779 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1780 					"not specified");
1781 			return 0;
1782 		}
1783 	}
1784 #endif
1785 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1786 		int blocksize =
1787 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1788 
1789 		if (blocksize < PAGE_SIZE) {
1790 			ext4_msg(sb, KERN_ERR, "can't mount with "
1791 				 "dioread_nolock if block size != PAGE_SIZE");
1792 			return 0;
1793 		}
1794 	}
1795 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1796 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1797 		ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1798 			 "in data=ordered mode");
1799 		return 0;
1800 	}
1801 	return 1;
1802 }
1803 
1804 static inline void ext4_show_quota_options(struct seq_file *seq,
1805 					   struct super_block *sb)
1806 {
1807 #if defined(CONFIG_QUOTA)
1808 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1809 
1810 	if (sbi->s_jquota_fmt) {
1811 		char *fmtname = "";
1812 
1813 		switch (sbi->s_jquota_fmt) {
1814 		case QFMT_VFS_OLD:
1815 			fmtname = "vfsold";
1816 			break;
1817 		case QFMT_VFS_V0:
1818 			fmtname = "vfsv0";
1819 			break;
1820 		case QFMT_VFS_V1:
1821 			fmtname = "vfsv1";
1822 			break;
1823 		}
1824 		seq_printf(seq, ",jqfmt=%s", fmtname);
1825 	}
1826 
1827 	if (sbi->s_qf_names[USRQUOTA])
1828 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1829 
1830 	if (sbi->s_qf_names[GRPQUOTA])
1831 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1832 #endif
1833 }
1834 
1835 static const char *token2str(int token)
1836 {
1837 	const struct match_token *t;
1838 
1839 	for (t = tokens; t->token != Opt_err; t++)
1840 		if (t->token == token && !strchr(t->pattern, '='))
1841 			break;
1842 	return t->pattern;
1843 }
1844 
1845 /*
1846  * Show an option if
1847  *  - it's set to a non-default value OR
1848  *  - if the per-sb default is different from the global default
1849  */
1850 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1851 			      int nodefs)
1852 {
1853 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1854 	struct ext4_super_block *es = sbi->s_es;
1855 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1856 	const struct mount_opts *m;
1857 	char sep = nodefs ? '\n' : ',';
1858 
1859 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1860 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1861 
1862 	if (sbi->s_sb_block != 1)
1863 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1864 
1865 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1866 		int want_set = m->flags & MOPT_SET;
1867 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1868 		    (m->flags & MOPT_CLEAR_ERR))
1869 			continue;
1870 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1871 			continue; /* skip if same as the default */
1872 		if ((want_set &&
1873 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1874 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1875 			continue; /* select Opt_noFoo vs Opt_Foo */
1876 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1877 	}
1878 
1879 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1880 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1881 		SEQ_OPTS_PRINT("resuid=%u",
1882 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1883 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1884 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1885 		SEQ_OPTS_PRINT("resgid=%u",
1886 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1887 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1888 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1889 		SEQ_OPTS_PUTS("errors=remount-ro");
1890 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1891 		SEQ_OPTS_PUTS("errors=continue");
1892 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1893 		SEQ_OPTS_PUTS("errors=panic");
1894 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1895 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1896 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1897 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1898 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1899 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1900 	if (sb->s_flags & MS_I_VERSION)
1901 		SEQ_OPTS_PUTS("i_version");
1902 	if (nodefs || sbi->s_stripe)
1903 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1904 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1905 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1906 			SEQ_OPTS_PUTS("data=journal");
1907 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1908 			SEQ_OPTS_PUTS("data=ordered");
1909 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1910 			SEQ_OPTS_PUTS("data=writeback");
1911 	}
1912 	if (nodefs ||
1913 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1914 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1915 			       sbi->s_inode_readahead_blks);
1916 
1917 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1918 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1919 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1920 	if (nodefs || sbi->s_max_dir_size_kb)
1921 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1922 	if (test_opt(sb, DATA_ERR_ABORT))
1923 		SEQ_OPTS_PUTS("data_err=abort");
1924 
1925 	ext4_show_quota_options(seq, sb);
1926 	return 0;
1927 }
1928 
1929 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1930 {
1931 	return _ext4_show_options(seq, root->d_sb, 0);
1932 }
1933 
1934 int ext4_seq_options_show(struct seq_file *seq, void *offset)
1935 {
1936 	struct super_block *sb = seq->private;
1937 	int rc;
1938 
1939 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1940 	rc = _ext4_show_options(seq, sb, 1);
1941 	seq_puts(seq, "\n");
1942 	return rc;
1943 }
1944 
1945 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1946 			    int read_only)
1947 {
1948 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1949 	int res = 0;
1950 
1951 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1952 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1953 			 "forcing read-only mode");
1954 		res = MS_RDONLY;
1955 	}
1956 	if (read_only)
1957 		goto done;
1958 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1959 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1960 			 "running e2fsck is recommended");
1961 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
1962 		ext4_msg(sb, KERN_WARNING,
1963 			 "warning: mounting fs with errors, "
1964 			 "running e2fsck is recommended");
1965 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1966 		 le16_to_cpu(es->s_mnt_count) >=
1967 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1968 		ext4_msg(sb, KERN_WARNING,
1969 			 "warning: maximal mount count reached, "
1970 			 "running e2fsck is recommended");
1971 	else if (le32_to_cpu(es->s_checkinterval) &&
1972 		(le32_to_cpu(es->s_lastcheck) +
1973 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1974 		ext4_msg(sb, KERN_WARNING,
1975 			 "warning: checktime reached, "
1976 			 "running e2fsck is recommended");
1977 	if (!sbi->s_journal)
1978 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1979 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1980 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1981 	le16_add_cpu(&es->s_mnt_count, 1);
1982 	es->s_mtime = cpu_to_le32(get_seconds());
1983 	ext4_update_dynamic_rev(sb);
1984 	if (sbi->s_journal)
1985 		ext4_set_feature_journal_needs_recovery(sb);
1986 
1987 	ext4_commit_super(sb, 1);
1988 done:
1989 	if (test_opt(sb, DEBUG))
1990 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1991 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1992 			sb->s_blocksize,
1993 			sbi->s_groups_count,
1994 			EXT4_BLOCKS_PER_GROUP(sb),
1995 			EXT4_INODES_PER_GROUP(sb),
1996 			sbi->s_mount_opt, sbi->s_mount_opt2);
1997 
1998 	cleancache_init_fs(sb);
1999 	return res;
2000 }
2001 
2002 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2003 {
2004 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2005 	struct flex_groups *new_groups;
2006 	int size;
2007 
2008 	if (!sbi->s_log_groups_per_flex)
2009 		return 0;
2010 
2011 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2012 	if (size <= sbi->s_flex_groups_allocated)
2013 		return 0;
2014 
2015 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2016 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2017 	if (!new_groups) {
2018 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2019 			 size / (int) sizeof(struct flex_groups));
2020 		return -ENOMEM;
2021 	}
2022 
2023 	if (sbi->s_flex_groups) {
2024 		memcpy(new_groups, sbi->s_flex_groups,
2025 		       (sbi->s_flex_groups_allocated *
2026 			sizeof(struct flex_groups)));
2027 		kvfree(sbi->s_flex_groups);
2028 	}
2029 	sbi->s_flex_groups = new_groups;
2030 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2031 	return 0;
2032 }
2033 
2034 static int ext4_fill_flex_info(struct super_block *sb)
2035 {
2036 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2037 	struct ext4_group_desc *gdp = NULL;
2038 	ext4_group_t flex_group;
2039 	int i, err;
2040 
2041 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2042 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2043 		sbi->s_log_groups_per_flex = 0;
2044 		return 1;
2045 	}
2046 
2047 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2048 	if (err)
2049 		goto failed;
2050 
2051 	for (i = 0; i < sbi->s_groups_count; i++) {
2052 		gdp = ext4_get_group_desc(sb, i, NULL);
2053 
2054 		flex_group = ext4_flex_group(sbi, i);
2055 		atomic_add(ext4_free_inodes_count(sb, gdp),
2056 			   &sbi->s_flex_groups[flex_group].free_inodes);
2057 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2058 			     &sbi->s_flex_groups[flex_group].free_clusters);
2059 		atomic_add(ext4_used_dirs_count(sb, gdp),
2060 			   &sbi->s_flex_groups[flex_group].used_dirs);
2061 	}
2062 
2063 	return 1;
2064 failed:
2065 	return 0;
2066 }
2067 
2068 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2069 				   struct ext4_group_desc *gdp)
2070 {
2071 	int offset;
2072 	__u16 crc = 0;
2073 	__le32 le_group = cpu_to_le32(block_group);
2074 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2075 
2076 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2077 		/* Use new metadata_csum algorithm */
2078 		__le16 save_csum;
2079 		__u32 csum32;
2080 
2081 		save_csum = gdp->bg_checksum;
2082 		gdp->bg_checksum = 0;
2083 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2084 				     sizeof(le_group));
2085 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2086 				     sbi->s_desc_size);
2087 		gdp->bg_checksum = save_csum;
2088 
2089 		crc = csum32 & 0xFFFF;
2090 		goto out;
2091 	}
2092 
2093 	/* old crc16 code */
2094 	if (!ext4_has_feature_gdt_csum(sb))
2095 		return 0;
2096 
2097 	offset = offsetof(struct ext4_group_desc, bg_checksum);
2098 
2099 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2100 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2101 	crc = crc16(crc, (__u8 *)gdp, offset);
2102 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2103 	/* for checksum of struct ext4_group_desc do the rest...*/
2104 	if (ext4_has_feature_64bit(sb) &&
2105 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2106 		crc = crc16(crc, (__u8 *)gdp + offset,
2107 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2108 				offset);
2109 
2110 out:
2111 	return cpu_to_le16(crc);
2112 }
2113 
2114 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2115 				struct ext4_group_desc *gdp)
2116 {
2117 	if (ext4_has_group_desc_csum(sb) &&
2118 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2119 		return 0;
2120 
2121 	return 1;
2122 }
2123 
2124 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2125 			      struct ext4_group_desc *gdp)
2126 {
2127 	if (!ext4_has_group_desc_csum(sb))
2128 		return;
2129 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2130 }
2131 
2132 /* Called at mount-time, super-block is locked */
2133 static int ext4_check_descriptors(struct super_block *sb,
2134 				  ext4_group_t *first_not_zeroed)
2135 {
2136 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2137 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2138 	ext4_fsblk_t last_block;
2139 	ext4_fsblk_t block_bitmap;
2140 	ext4_fsblk_t inode_bitmap;
2141 	ext4_fsblk_t inode_table;
2142 	int flexbg_flag = 0;
2143 	ext4_group_t i, grp = sbi->s_groups_count;
2144 
2145 	if (ext4_has_feature_flex_bg(sb))
2146 		flexbg_flag = 1;
2147 
2148 	ext4_debug("Checking group descriptors");
2149 
2150 	for (i = 0; i < sbi->s_groups_count; i++) {
2151 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2152 
2153 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2154 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2155 		else
2156 			last_block = first_block +
2157 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2158 
2159 		if ((grp == sbi->s_groups_count) &&
2160 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2161 			grp = i;
2162 
2163 		block_bitmap = ext4_block_bitmap(sb, gdp);
2164 		if (block_bitmap < first_block || block_bitmap > last_block) {
2165 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2166 			       "Block bitmap for group %u not in group "
2167 			       "(block %llu)!", i, block_bitmap);
2168 			return 0;
2169 		}
2170 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2171 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2172 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2173 			       "Inode bitmap for group %u not in group "
2174 			       "(block %llu)!", i, inode_bitmap);
2175 			return 0;
2176 		}
2177 		inode_table = ext4_inode_table(sb, gdp);
2178 		if (inode_table < first_block ||
2179 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2180 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2181 			       "Inode table for group %u not in group "
2182 			       "(block %llu)!", i, inode_table);
2183 			return 0;
2184 		}
2185 		ext4_lock_group(sb, i);
2186 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2187 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2188 				 "Checksum for group %u failed (%u!=%u)",
2189 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2190 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2191 			if (!(sb->s_flags & MS_RDONLY)) {
2192 				ext4_unlock_group(sb, i);
2193 				return 0;
2194 			}
2195 		}
2196 		ext4_unlock_group(sb, i);
2197 		if (!flexbg_flag)
2198 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2199 	}
2200 	if (NULL != first_not_zeroed)
2201 		*first_not_zeroed = grp;
2202 	return 1;
2203 }
2204 
2205 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2206  * the superblock) which were deleted from all directories, but held open by
2207  * a process at the time of a crash.  We walk the list and try to delete these
2208  * inodes at recovery time (only with a read-write filesystem).
2209  *
2210  * In order to keep the orphan inode chain consistent during traversal (in
2211  * case of crash during recovery), we link each inode into the superblock
2212  * orphan list_head and handle it the same way as an inode deletion during
2213  * normal operation (which journals the operations for us).
2214  *
2215  * We only do an iget() and an iput() on each inode, which is very safe if we
2216  * accidentally point at an in-use or already deleted inode.  The worst that
2217  * can happen in this case is that we get a "bit already cleared" message from
2218  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2219  * e2fsck was run on this filesystem, and it must have already done the orphan
2220  * inode cleanup for us, so we can safely abort without any further action.
2221  */
2222 static void ext4_orphan_cleanup(struct super_block *sb,
2223 				struct ext4_super_block *es)
2224 {
2225 	unsigned int s_flags = sb->s_flags;
2226 	int nr_orphans = 0, nr_truncates = 0;
2227 #ifdef CONFIG_QUOTA
2228 	int i;
2229 #endif
2230 	if (!es->s_last_orphan) {
2231 		jbd_debug(4, "no orphan inodes to clean up\n");
2232 		return;
2233 	}
2234 
2235 	if (bdev_read_only(sb->s_bdev)) {
2236 		ext4_msg(sb, KERN_ERR, "write access "
2237 			"unavailable, skipping orphan cleanup");
2238 		return;
2239 	}
2240 
2241 	/* Check if feature set would not allow a r/w mount */
2242 	if (!ext4_feature_set_ok(sb, 0)) {
2243 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2244 			 "unknown ROCOMPAT features");
2245 		return;
2246 	}
2247 
2248 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2249 		/* don't clear list on RO mount w/ errors */
2250 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2251 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2252 				  "clearing orphan list.\n");
2253 			es->s_last_orphan = 0;
2254 		}
2255 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2256 		return;
2257 	}
2258 
2259 	if (s_flags & MS_RDONLY) {
2260 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2261 		sb->s_flags &= ~MS_RDONLY;
2262 	}
2263 #ifdef CONFIG_QUOTA
2264 	/* Needed for iput() to work correctly and not trash data */
2265 	sb->s_flags |= MS_ACTIVE;
2266 	/* Turn on quotas so that they are updated correctly */
2267 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2268 		if (EXT4_SB(sb)->s_qf_names[i]) {
2269 			int ret = ext4_quota_on_mount(sb, i);
2270 			if (ret < 0)
2271 				ext4_msg(sb, KERN_ERR,
2272 					"Cannot turn on journaled "
2273 					"quota: error %d", ret);
2274 		}
2275 	}
2276 #endif
2277 
2278 	while (es->s_last_orphan) {
2279 		struct inode *inode;
2280 
2281 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2282 		if (IS_ERR(inode)) {
2283 			es->s_last_orphan = 0;
2284 			break;
2285 		}
2286 
2287 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2288 		dquot_initialize(inode);
2289 		if (inode->i_nlink) {
2290 			if (test_opt(sb, DEBUG))
2291 				ext4_msg(sb, KERN_DEBUG,
2292 					"%s: truncating inode %lu to %lld bytes",
2293 					__func__, inode->i_ino, inode->i_size);
2294 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2295 				  inode->i_ino, inode->i_size);
2296 			inode_lock(inode);
2297 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2298 			ext4_truncate(inode);
2299 			inode_unlock(inode);
2300 			nr_truncates++;
2301 		} else {
2302 			if (test_opt(sb, DEBUG))
2303 				ext4_msg(sb, KERN_DEBUG,
2304 					"%s: deleting unreferenced inode %lu",
2305 					__func__, inode->i_ino);
2306 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2307 				  inode->i_ino);
2308 			nr_orphans++;
2309 		}
2310 		iput(inode);  /* The delete magic happens here! */
2311 	}
2312 
2313 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2314 
2315 	if (nr_orphans)
2316 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2317 		       PLURAL(nr_orphans));
2318 	if (nr_truncates)
2319 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2320 		       PLURAL(nr_truncates));
2321 #ifdef CONFIG_QUOTA
2322 	/* Turn quotas off */
2323 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2324 		if (sb_dqopt(sb)->files[i])
2325 			dquot_quota_off(sb, i);
2326 	}
2327 #endif
2328 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2329 }
2330 
2331 /*
2332  * Maximal extent format file size.
2333  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2334  * extent format containers, within a sector_t, and within i_blocks
2335  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2336  * so that won't be a limiting factor.
2337  *
2338  * However there is other limiting factor. We do store extents in the form
2339  * of starting block and length, hence the resulting length of the extent
2340  * covering maximum file size must fit into on-disk format containers as
2341  * well. Given that length is always by 1 unit bigger than max unit (because
2342  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2343  *
2344  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2345  */
2346 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2347 {
2348 	loff_t res;
2349 	loff_t upper_limit = MAX_LFS_FILESIZE;
2350 
2351 	/* small i_blocks in vfs inode? */
2352 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2353 		/*
2354 		 * CONFIG_LBDAF is not enabled implies the inode
2355 		 * i_block represent total blocks in 512 bytes
2356 		 * 32 == size of vfs inode i_blocks * 8
2357 		 */
2358 		upper_limit = (1LL << 32) - 1;
2359 
2360 		/* total blocks in file system block size */
2361 		upper_limit >>= (blkbits - 9);
2362 		upper_limit <<= blkbits;
2363 	}
2364 
2365 	/*
2366 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2367 	 * by one fs block, so ee_len can cover the extent of maximum file
2368 	 * size
2369 	 */
2370 	res = (1LL << 32) - 1;
2371 	res <<= blkbits;
2372 
2373 	/* Sanity check against vm- & vfs- imposed limits */
2374 	if (res > upper_limit)
2375 		res = upper_limit;
2376 
2377 	return res;
2378 }
2379 
2380 /*
2381  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2382  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2383  * We need to be 1 filesystem block less than the 2^48 sector limit.
2384  */
2385 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2386 {
2387 	loff_t res = EXT4_NDIR_BLOCKS;
2388 	int meta_blocks;
2389 	loff_t upper_limit;
2390 	/* This is calculated to be the largest file size for a dense, block
2391 	 * mapped file such that the file's total number of 512-byte sectors,
2392 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2393 	 *
2394 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2395 	 * number of 512-byte sectors of the file.
2396 	 */
2397 
2398 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2399 		/*
2400 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2401 		 * the inode i_block field represents total file blocks in
2402 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2403 		 */
2404 		upper_limit = (1LL << 32) - 1;
2405 
2406 		/* total blocks in file system block size */
2407 		upper_limit >>= (bits - 9);
2408 
2409 	} else {
2410 		/*
2411 		 * We use 48 bit ext4_inode i_blocks
2412 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2413 		 * represent total number of blocks in
2414 		 * file system block size
2415 		 */
2416 		upper_limit = (1LL << 48) - 1;
2417 
2418 	}
2419 
2420 	/* indirect blocks */
2421 	meta_blocks = 1;
2422 	/* double indirect blocks */
2423 	meta_blocks += 1 + (1LL << (bits-2));
2424 	/* tripple indirect blocks */
2425 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2426 
2427 	upper_limit -= meta_blocks;
2428 	upper_limit <<= bits;
2429 
2430 	res += 1LL << (bits-2);
2431 	res += 1LL << (2*(bits-2));
2432 	res += 1LL << (3*(bits-2));
2433 	res <<= bits;
2434 	if (res > upper_limit)
2435 		res = upper_limit;
2436 
2437 	if (res > MAX_LFS_FILESIZE)
2438 		res = MAX_LFS_FILESIZE;
2439 
2440 	return res;
2441 }
2442 
2443 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2444 				   ext4_fsblk_t logical_sb_block, int nr)
2445 {
2446 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2447 	ext4_group_t bg, first_meta_bg;
2448 	int has_super = 0;
2449 
2450 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2451 
2452 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2453 		return logical_sb_block + nr + 1;
2454 	bg = sbi->s_desc_per_block * nr;
2455 	if (ext4_bg_has_super(sb, bg))
2456 		has_super = 1;
2457 
2458 	/*
2459 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2460 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2461 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2462 	 * compensate.
2463 	 */
2464 	if (sb->s_blocksize == 1024 && nr == 0 &&
2465 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2466 		has_super++;
2467 
2468 	return (has_super + ext4_group_first_block_no(sb, bg));
2469 }
2470 
2471 /**
2472  * ext4_get_stripe_size: Get the stripe size.
2473  * @sbi: In memory super block info
2474  *
2475  * If we have specified it via mount option, then
2476  * use the mount option value. If the value specified at mount time is
2477  * greater than the blocks per group use the super block value.
2478  * If the super block value is greater than blocks per group return 0.
2479  * Allocator needs it be less than blocks per group.
2480  *
2481  */
2482 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2483 {
2484 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2485 	unsigned long stripe_width =
2486 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2487 	int ret;
2488 
2489 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2490 		ret = sbi->s_stripe;
2491 	else if (stripe_width <= sbi->s_blocks_per_group)
2492 		ret = stripe_width;
2493 	else if (stride <= sbi->s_blocks_per_group)
2494 		ret = stride;
2495 	else
2496 		ret = 0;
2497 
2498 	/*
2499 	 * If the stripe width is 1, this makes no sense and
2500 	 * we set it to 0 to turn off stripe handling code.
2501 	 */
2502 	if (ret <= 1)
2503 		ret = 0;
2504 
2505 	return ret;
2506 }
2507 
2508 /*
2509  * Check whether this filesystem can be mounted based on
2510  * the features present and the RDONLY/RDWR mount requested.
2511  * Returns 1 if this filesystem can be mounted as requested,
2512  * 0 if it cannot be.
2513  */
2514 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2515 {
2516 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2517 		ext4_msg(sb, KERN_ERR,
2518 			"Couldn't mount because of "
2519 			"unsupported optional features (%x)",
2520 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2521 			~EXT4_FEATURE_INCOMPAT_SUPP));
2522 		return 0;
2523 	}
2524 
2525 	if (readonly)
2526 		return 1;
2527 
2528 	if (ext4_has_feature_readonly(sb)) {
2529 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2530 		sb->s_flags |= MS_RDONLY;
2531 		return 1;
2532 	}
2533 
2534 	/* Check that feature set is OK for a read-write mount */
2535 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2536 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2537 			 "unsupported optional features (%x)",
2538 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2539 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2540 		return 0;
2541 	}
2542 	/*
2543 	 * Large file size enabled file system can only be mounted
2544 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2545 	 */
2546 	if (ext4_has_feature_huge_file(sb)) {
2547 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2548 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2549 				 "cannot be mounted RDWR without "
2550 				 "CONFIG_LBDAF");
2551 			return 0;
2552 		}
2553 	}
2554 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2555 		ext4_msg(sb, KERN_ERR,
2556 			 "Can't support bigalloc feature without "
2557 			 "extents feature\n");
2558 		return 0;
2559 	}
2560 
2561 #ifndef CONFIG_QUOTA
2562 	if (ext4_has_feature_quota(sb) && !readonly) {
2563 		ext4_msg(sb, KERN_ERR,
2564 			 "Filesystem with quota feature cannot be mounted RDWR "
2565 			 "without CONFIG_QUOTA");
2566 		return 0;
2567 	}
2568 	if (ext4_has_feature_project(sb) && !readonly) {
2569 		ext4_msg(sb, KERN_ERR,
2570 			 "Filesystem with project quota feature cannot be mounted RDWR "
2571 			 "without CONFIG_QUOTA");
2572 		return 0;
2573 	}
2574 #endif  /* CONFIG_QUOTA */
2575 	return 1;
2576 }
2577 
2578 /*
2579  * This function is called once a day if we have errors logged
2580  * on the file system
2581  */
2582 static void print_daily_error_info(unsigned long arg)
2583 {
2584 	struct super_block *sb = (struct super_block *) arg;
2585 	struct ext4_sb_info *sbi;
2586 	struct ext4_super_block *es;
2587 
2588 	sbi = EXT4_SB(sb);
2589 	es = sbi->s_es;
2590 
2591 	if (es->s_error_count)
2592 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2593 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2594 			 le32_to_cpu(es->s_error_count));
2595 	if (es->s_first_error_time) {
2596 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2597 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2598 		       (int) sizeof(es->s_first_error_func),
2599 		       es->s_first_error_func,
2600 		       le32_to_cpu(es->s_first_error_line));
2601 		if (es->s_first_error_ino)
2602 			printk(": inode %u",
2603 			       le32_to_cpu(es->s_first_error_ino));
2604 		if (es->s_first_error_block)
2605 			printk(": block %llu", (unsigned long long)
2606 			       le64_to_cpu(es->s_first_error_block));
2607 		printk("\n");
2608 	}
2609 	if (es->s_last_error_time) {
2610 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2611 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2612 		       (int) sizeof(es->s_last_error_func),
2613 		       es->s_last_error_func,
2614 		       le32_to_cpu(es->s_last_error_line));
2615 		if (es->s_last_error_ino)
2616 			printk(": inode %u",
2617 			       le32_to_cpu(es->s_last_error_ino));
2618 		if (es->s_last_error_block)
2619 			printk(": block %llu", (unsigned long long)
2620 			       le64_to_cpu(es->s_last_error_block));
2621 		printk("\n");
2622 	}
2623 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2624 }
2625 
2626 /* Find next suitable group and run ext4_init_inode_table */
2627 static int ext4_run_li_request(struct ext4_li_request *elr)
2628 {
2629 	struct ext4_group_desc *gdp = NULL;
2630 	ext4_group_t group, ngroups;
2631 	struct super_block *sb;
2632 	unsigned long timeout = 0;
2633 	int ret = 0;
2634 
2635 	sb = elr->lr_super;
2636 	ngroups = EXT4_SB(sb)->s_groups_count;
2637 
2638 	sb_start_write(sb);
2639 	for (group = elr->lr_next_group; group < ngroups; group++) {
2640 		gdp = ext4_get_group_desc(sb, group, NULL);
2641 		if (!gdp) {
2642 			ret = 1;
2643 			break;
2644 		}
2645 
2646 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2647 			break;
2648 	}
2649 
2650 	if (group >= ngroups)
2651 		ret = 1;
2652 
2653 	if (!ret) {
2654 		timeout = jiffies;
2655 		ret = ext4_init_inode_table(sb, group,
2656 					    elr->lr_timeout ? 0 : 1);
2657 		if (elr->lr_timeout == 0) {
2658 			timeout = (jiffies - timeout) *
2659 				  elr->lr_sbi->s_li_wait_mult;
2660 			elr->lr_timeout = timeout;
2661 		}
2662 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2663 		elr->lr_next_group = group + 1;
2664 	}
2665 	sb_end_write(sb);
2666 
2667 	return ret;
2668 }
2669 
2670 /*
2671  * Remove lr_request from the list_request and free the
2672  * request structure. Should be called with li_list_mtx held
2673  */
2674 static void ext4_remove_li_request(struct ext4_li_request *elr)
2675 {
2676 	struct ext4_sb_info *sbi;
2677 
2678 	if (!elr)
2679 		return;
2680 
2681 	sbi = elr->lr_sbi;
2682 
2683 	list_del(&elr->lr_request);
2684 	sbi->s_li_request = NULL;
2685 	kfree(elr);
2686 }
2687 
2688 static void ext4_unregister_li_request(struct super_block *sb)
2689 {
2690 	mutex_lock(&ext4_li_mtx);
2691 	if (!ext4_li_info) {
2692 		mutex_unlock(&ext4_li_mtx);
2693 		return;
2694 	}
2695 
2696 	mutex_lock(&ext4_li_info->li_list_mtx);
2697 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2698 	mutex_unlock(&ext4_li_info->li_list_mtx);
2699 	mutex_unlock(&ext4_li_mtx);
2700 }
2701 
2702 static struct task_struct *ext4_lazyinit_task;
2703 
2704 /*
2705  * This is the function where ext4lazyinit thread lives. It walks
2706  * through the request list searching for next scheduled filesystem.
2707  * When such a fs is found, run the lazy initialization request
2708  * (ext4_rn_li_request) and keep track of the time spend in this
2709  * function. Based on that time we compute next schedule time of
2710  * the request. When walking through the list is complete, compute
2711  * next waking time and put itself into sleep.
2712  */
2713 static int ext4_lazyinit_thread(void *arg)
2714 {
2715 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2716 	struct list_head *pos, *n;
2717 	struct ext4_li_request *elr;
2718 	unsigned long next_wakeup, cur;
2719 
2720 	BUG_ON(NULL == eli);
2721 
2722 cont_thread:
2723 	while (true) {
2724 		next_wakeup = MAX_JIFFY_OFFSET;
2725 
2726 		mutex_lock(&eli->li_list_mtx);
2727 		if (list_empty(&eli->li_request_list)) {
2728 			mutex_unlock(&eli->li_list_mtx);
2729 			goto exit_thread;
2730 		}
2731 
2732 		list_for_each_safe(pos, n, &eli->li_request_list) {
2733 			elr = list_entry(pos, struct ext4_li_request,
2734 					 lr_request);
2735 
2736 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2737 				if (ext4_run_li_request(elr) != 0) {
2738 					/* error, remove the lazy_init job */
2739 					ext4_remove_li_request(elr);
2740 					continue;
2741 				}
2742 			}
2743 
2744 			if (time_before(elr->lr_next_sched, next_wakeup))
2745 				next_wakeup = elr->lr_next_sched;
2746 		}
2747 		mutex_unlock(&eli->li_list_mtx);
2748 
2749 		try_to_freeze();
2750 
2751 		cur = jiffies;
2752 		if ((time_after_eq(cur, next_wakeup)) ||
2753 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2754 			cond_resched();
2755 			continue;
2756 		}
2757 
2758 		schedule_timeout_interruptible(next_wakeup - cur);
2759 
2760 		if (kthread_should_stop()) {
2761 			ext4_clear_request_list();
2762 			goto exit_thread;
2763 		}
2764 	}
2765 
2766 exit_thread:
2767 	/*
2768 	 * It looks like the request list is empty, but we need
2769 	 * to check it under the li_list_mtx lock, to prevent any
2770 	 * additions into it, and of course we should lock ext4_li_mtx
2771 	 * to atomically free the list and ext4_li_info, because at
2772 	 * this point another ext4 filesystem could be registering
2773 	 * new one.
2774 	 */
2775 	mutex_lock(&ext4_li_mtx);
2776 	mutex_lock(&eli->li_list_mtx);
2777 	if (!list_empty(&eli->li_request_list)) {
2778 		mutex_unlock(&eli->li_list_mtx);
2779 		mutex_unlock(&ext4_li_mtx);
2780 		goto cont_thread;
2781 	}
2782 	mutex_unlock(&eli->li_list_mtx);
2783 	kfree(ext4_li_info);
2784 	ext4_li_info = NULL;
2785 	mutex_unlock(&ext4_li_mtx);
2786 
2787 	return 0;
2788 }
2789 
2790 static void ext4_clear_request_list(void)
2791 {
2792 	struct list_head *pos, *n;
2793 	struct ext4_li_request *elr;
2794 
2795 	mutex_lock(&ext4_li_info->li_list_mtx);
2796 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2797 		elr = list_entry(pos, struct ext4_li_request,
2798 				 lr_request);
2799 		ext4_remove_li_request(elr);
2800 	}
2801 	mutex_unlock(&ext4_li_info->li_list_mtx);
2802 }
2803 
2804 static int ext4_run_lazyinit_thread(void)
2805 {
2806 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2807 					 ext4_li_info, "ext4lazyinit");
2808 	if (IS_ERR(ext4_lazyinit_task)) {
2809 		int err = PTR_ERR(ext4_lazyinit_task);
2810 		ext4_clear_request_list();
2811 		kfree(ext4_li_info);
2812 		ext4_li_info = NULL;
2813 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2814 				 "initialization thread\n",
2815 				 err);
2816 		return err;
2817 	}
2818 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2819 	return 0;
2820 }
2821 
2822 /*
2823  * Check whether it make sense to run itable init. thread or not.
2824  * If there is at least one uninitialized inode table, return
2825  * corresponding group number, else the loop goes through all
2826  * groups and return total number of groups.
2827  */
2828 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2829 {
2830 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2831 	struct ext4_group_desc *gdp = NULL;
2832 
2833 	for (group = 0; group < ngroups; group++) {
2834 		gdp = ext4_get_group_desc(sb, group, NULL);
2835 		if (!gdp)
2836 			continue;
2837 
2838 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2839 			break;
2840 	}
2841 
2842 	return group;
2843 }
2844 
2845 static int ext4_li_info_new(void)
2846 {
2847 	struct ext4_lazy_init *eli = NULL;
2848 
2849 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2850 	if (!eli)
2851 		return -ENOMEM;
2852 
2853 	INIT_LIST_HEAD(&eli->li_request_list);
2854 	mutex_init(&eli->li_list_mtx);
2855 
2856 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2857 
2858 	ext4_li_info = eli;
2859 
2860 	return 0;
2861 }
2862 
2863 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2864 					    ext4_group_t start)
2865 {
2866 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2867 	struct ext4_li_request *elr;
2868 
2869 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2870 	if (!elr)
2871 		return NULL;
2872 
2873 	elr->lr_super = sb;
2874 	elr->lr_sbi = sbi;
2875 	elr->lr_next_group = start;
2876 
2877 	/*
2878 	 * Randomize first schedule time of the request to
2879 	 * spread the inode table initialization requests
2880 	 * better.
2881 	 */
2882 	elr->lr_next_sched = jiffies + (prandom_u32() %
2883 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
2884 	return elr;
2885 }
2886 
2887 int ext4_register_li_request(struct super_block *sb,
2888 			     ext4_group_t first_not_zeroed)
2889 {
2890 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2891 	struct ext4_li_request *elr = NULL;
2892 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2893 	int ret = 0;
2894 
2895 	mutex_lock(&ext4_li_mtx);
2896 	if (sbi->s_li_request != NULL) {
2897 		/*
2898 		 * Reset timeout so it can be computed again, because
2899 		 * s_li_wait_mult might have changed.
2900 		 */
2901 		sbi->s_li_request->lr_timeout = 0;
2902 		goto out;
2903 	}
2904 
2905 	if (first_not_zeroed == ngroups ||
2906 	    (sb->s_flags & MS_RDONLY) ||
2907 	    !test_opt(sb, INIT_INODE_TABLE))
2908 		goto out;
2909 
2910 	elr = ext4_li_request_new(sb, first_not_zeroed);
2911 	if (!elr) {
2912 		ret = -ENOMEM;
2913 		goto out;
2914 	}
2915 
2916 	if (NULL == ext4_li_info) {
2917 		ret = ext4_li_info_new();
2918 		if (ret)
2919 			goto out;
2920 	}
2921 
2922 	mutex_lock(&ext4_li_info->li_list_mtx);
2923 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2924 	mutex_unlock(&ext4_li_info->li_list_mtx);
2925 
2926 	sbi->s_li_request = elr;
2927 	/*
2928 	 * set elr to NULL here since it has been inserted to
2929 	 * the request_list and the removal and free of it is
2930 	 * handled by ext4_clear_request_list from now on.
2931 	 */
2932 	elr = NULL;
2933 
2934 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2935 		ret = ext4_run_lazyinit_thread();
2936 		if (ret)
2937 			goto out;
2938 	}
2939 out:
2940 	mutex_unlock(&ext4_li_mtx);
2941 	if (ret)
2942 		kfree(elr);
2943 	return ret;
2944 }
2945 
2946 /*
2947  * We do not need to lock anything since this is called on
2948  * module unload.
2949  */
2950 static void ext4_destroy_lazyinit_thread(void)
2951 {
2952 	/*
2953 	 * If thread exited earlier
2954 	 * there's nothing to be done.
2955 	 */
2956 	if (!ext4_li_info || !ext4_lazyinit_task)
2957 		return;
2958 
2959 	kthread_stop(ext4_lazyinit_task);
2960 }
2961 
2962 static int set_journal_csum_feature_set(struct super_block *sb)
2963 {
2964 	int ret = 1;
2965 	int compat, incompat;
2966 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2967 
2968 	if (ext4_has_metadata_csum(sb)) {
2969 		/* journal checksum v3 */
2970 		compat = 0;
2971 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
2972 	} else {
2973 		/* journal checksum v1 */
2974 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
2975 		incompat = 0;
2976 	}
2977 
2978 	jbd2_journal_clear_features(sbi->s_journal,
2979 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
2980 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
2981 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
2982 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
2983 		ret = jbd2_journal_set_features(sbi->s_journal,
2984 				compat, 0,
2985 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
2986 				incompat);
2987 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
2988 		ret = jbd2_journal_set_features(sbi->s_journal,
2989 				compat, 0,
2990 				incompat);
2991 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2992 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2993 	} else {
2994 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
2995 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
2996 	}
2997 
2998 	return ret;
2999 }
3000 
3001 /*
3002  * Note: calculating the overhead so we can be compatible with
3003  * historical BSD practice is quite difficult in the face of
3004  * clusters/bigalloc.  This is because multiple metadata blocks from
3005  * different block group can end up in the same allocation cluster.
3006  * Calculating the exact overhead in the face of clustered allocation
3007  * requires either O(all block bitmaps) in memory or O(number of block
3008  * groups**2) in time.  We will still calculate the superblock for
3009  * older file systems --- and if we come across with a bigalloc file
3010  * system with zero in s_overhead_clusters the estimate will be close to
3011  * correct especially for very large cluster sizes --- but for newer
3012  * file systems, it's better to calculate this figure once at mkfs
3013  * time, and store it in the superblock.  If the superblock value is
3014  * present (even for non-bigalloc file systems), we will use it.
3015  */
3016 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3017 			  char *buf)
3018 {
3019 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3020 	struct ext4_group_desc	*gdp;
3021 	ext4_fsblk_t		first_block, last_block, b;
3022 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3023 	int			s, j, count = 0;
3024 
3025 	if (!ext4_has_feature_bigalloc(sb))
3026 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3027 			sbi->s_itb_per_group + 2);
3028 
3029 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3030 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3031 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3032 	for (i = 0; i < ngroups; i++) {
3033 		gdp = ext4_get_group_desc(sb, i, NULL);
3034 		b = ext4_block_bitmap(sb, gdp);
3035 		if (b >= first_block && b <= last_block) {
3036 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3037 			count++;
3038 		}
3039 		b = ext4_inode_bitmap(sb, gdp);
3040 		if (b >= first_block && b <= last_block) {
3041 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3042 			count++;
3043 		}
3044 		b = ext4_inode_table(sb, gdp);
3045 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3046 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3047 				int c = EXT4_B2C(sbi, b - first_block);
3048 				ext4_set_bit(c, buf);
3049 				count++;
3050 			}
3051 		if (i != grp)
3052 			continue;
3053 		s = 0;
3054 		if (ext4_bg_has_super(sb, grp)) {
3055 			ext4_set_bit(s++, buf);
3056 			count++;
3057 		}
3058 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3059 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3060 			count++;
3061 		}
3062 	}
3063 	if (!count)
3064 		return 0;
3065 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3066 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3067 }
3068 
3069 /*
3070  * Compute the overhead and stash it in sbi->s_overhead
3071  */
3072 int ext4_calculate_overhead(struct super_block *sb)
3073 {
3074 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3075 	struct ext4_super_block *es = sbi->s_es;
3076 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3077 	ext4_fsblk_t overhead = 0;
3078 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3079 
3080 	if (!buf)
3081 		return -ENOMEM;
3082 
3083 	/*
3084 	 * Compute the overhead (FS structures).  This is constant
3085 	 * for a given filesystem unless the number of block groups
3086 	 * changes so we cache the previous value until it does.
3087 	 */
3088 
3089 	/*
3090 	 * All of the blocks before first_data_block are overhead
3091 	 */
3092 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3093 
3094 	/*
3095 	 * Add the overhead found in each block group
3096 	 */
3097 	for (i = 0; i < ngroups; i++) {
3098 		int blks;
3099 
3100 		blks = count_overhead(sb, i, buf);
3101 		overhead += blks;
3102 		if (blks)
3103 			memset(buf, 0, PAGE_SIZE);
3104 		cond_resched();
3105 	}
3106 	/* Add the internal journal blocks as well */
3107 	if (sbi->s_journal && !sbi->journal_bdev)
3108 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3109 
3110 	sbi->s_overhead = overhead;
3111 	smp_wmb();
3112 	free_page((unsigned long) buf);
3113 	return 0;
3114 }
3115 
3116 static void ext4_set_resv_clusters(struct super_block *sb)
3117 {
3118 	ext4_fsblk_t resv_clusters;
3119 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3120 
3121 	/*
3122 	 * There's no need to reserve anything when we aren't using extents.
3123 	 * The space estimates are exact, there are no unwritten extents,
3124 	 * hole punching doesn't need new metadata... This is needed especially
3125 	 * to keep ext2/3 backward compatibility.
3126 	 */
3127 	if (!ext4_has_feature_extents(sb))
3128 		return;
3129 	/*
3130 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3131 	 * This should cover the situations where we can not afford to run
3132 	 * out of space like for example punch hole, or converting
3133 	 * unwritten extents in delalloc path. In most cases such
3134 	 * allocation would require 1, or 2 blocks, higher numbers are
3135 	 * very rare.
3136 	 */
3137 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3138 			 sbi->s_cluster_bits);
3139 
3140 	do_div(resv_clusters, 50);
3141 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3142 
3143 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3144 }
3145 
3146 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3147 {
3148 	char *orig_data = kstrdup(data, GFP_KERNEL);
3149 	struct buffer_head *bh;
3150 	struct ext4_super_block *es = NULL;
3151 	struct ext4_sb_info *sbi;
3152 	ext4_fsblk_t block;
3153 	ext4_fsblk_t sb_block = get_sb_block(&data);
3154 	ext4_fsblk_t logical_sb_block;
3155 	unsigned long offset = 0;
3156 	unsigned long journal_devnum = 0;
3157 	unsigned long def_mount_opts;
3158 	struct inode *root;
3159 	const char *descr;
3160 	int ret = -ENOMEM;
3161 	int blocksize, clustersize;
3162 	unsigned int db_count;
3163 	unsigned int i;
3164 	int needs_recovery, has_huge_files, has_bigalloc;
3165 	__u64 blocks_count;
3166 	int err = 0;
3167 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3168 	ext4_group_t first_not_zeroed;
3169 
3170 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3171 	if (!sbi)
3172 		goto out_free_orig;
3173 
3174 	sbi->s_blockgroup_lock =
3175 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3176 	if (!sbi->s_blockgroup_lock) {
3177 		kfree(sbi);
3178 		goto out_free_orig;
3179 	}
3180 	sb->s_fs_info = sbi;
3181 	sbi->s_sb = sb;
3182 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3183 	sbi->s_sb_block = sb_block;
3184 	if (sb->s_bdev->bd_part)
3185 		sbi->s_sectors_written_start =
3186 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3187 
3188 	/* Cleanup superblock name */
3189 	strreplace(sb->s_id, '/', '!');
3190 
3191 	/* -EINVAL is default */
3192 	ret = -EINVAL;
3193 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3194 	if (!blocksize) {
3195 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3196 		goto out_fail;
3197 	}
3198 
3199 	/*
3200 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3201 	 * block sizes.  We need to calculate the offset from buffer start.
3202 	 */
3203 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3204 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3205 		offset = do_div(logical_sb_block, blocksize);
3206 	} else {
3207 		logical_sb_block = sb_block;
3208 	}
3209 
3210 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3211 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3212 		goto out_fail;
3213 	}
3214 	/*
3215 	 * Note: s_es must be initialized as soon as possible because
3216 	 *       some ext4 macro-instructions depend on its value
3217 	 */
3218 	es = (struct ext4_super_block *) (bh->b_data + offset);
3219 	sbi->s_es = es;
3220 	sb->s_magic = le16_to_cpu(es->s_magic);
3221 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3222 		goto cantfind_ext4;
3223 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3224 
3225 	/* Warn if metadata_csum and gdt_csum are both set. */
3226 	if (ext4_has_feature_metadata_csum(sb) &&
3227 	    ext4_has_feature_gdt_csum(sb))
3228 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3229 			     "redundant flags; please run fsck.");
3230 
3231 	/* Check for a known checksum algorithm */
3232 	if (!ext4_verify_csum_type(sb, es)) {
3233 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3234 			 "unknown checksum algorithm.");
3235 		silent = 1;
3236 		goto cantfind_ext4;
3237 	}
3238 
3239 	/* Load the checksum driver */
3240 	if (ext4_has_feature_metadata_csum(sb)) {
3241 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3242 		if (IS_ERR(sbi->s_chksum_driver)) {
3243 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3244 			ret = PTR_ERR(sbi->s_chksum_driver);
3245 			sbi->s_chksum_driver = NULL;
3246 			goto failed_mount;
3247 		}
3248 	}
3249 
3250 	/* Check superblock checksum */
3251 	if (!ext4_superblock_csum_verify(sb, es)) {
3252 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3253 			 "invalid superblock checksum.  Run e2fsck?");
3254 		silent = 1;
3255 		ret = -EFSBADCRC;
3256 		goto cantfind_ext4;
3257 	}
3258 
3259 	/* Precompute checksum seed for all metadata */
3260 	if (ext4_has_feature_csum_seed(sb))
3261 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3262 	else if (ext4_has_metadata_csum(sb))
3263 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3264 					       sizeof(es->s_uuid));
3265 
3266 	/* Set defaults before we parse the mount options */
3267 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3268 	set_opt(sb, INIT_INODE_TABLE);
3269 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3270 		set_opt(sb, DEBUG);
3271 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3272 		set_opt(sb, GRPID);
3273 	if (def_mount_opts & EXT4_DEFM_UID16)
3274 		set_opt(sb, NO_UID32);
3275 	/* xattr user namespace & acls are now defaulted on */
3276 	set_opt(sb, XATTR_USER);
3277 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3278 	set_opt(sb, POSIX_ACL);
3279 #endif
3280 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3281 	if (ext4_has_metadata_csum(sb))
3282 		set_opt(sb, JOURNAL_CHECKSUM);
3283 
3284 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3285 		set_opt(sb, JOURNAL_DATA);
3286 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3287 		set_opt(sb, ORDERED_DATA);
3288 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3289 		set_opt(sb, WRITEBACK_DATA);
3290 
3291 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3292 		set_opt(sb, ERRORS_PANIC);
3293 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3294 		set_opt(sb, ERRORS_CONT);
3295 	else
3296 		set_opt(sb, ERRORS_RO);
3297 	/* block_validity enabled by default; disable with noblock_validity */
3298 	set_opt(sb, BLOCK_VALIDITY);
3299 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3300 		set_opt(sb, DISCARD);
3301 
3302 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3303 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3304 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3305 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3306 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3307 
3308 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3309 		set_opt(sb, BARRIER);
3310 
3311 	/*
3312 	 * enable delayed allocation by default
3313 	 * Use -o nodelalloc to turn it off
3314 	 */
3315 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3316 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3317 		set_opt(sb, DELALLOC);
3318 
3319 	/*
3320 	 * set default s_li_wait_mult for lazyinit, for the case there is
3321 	 * no mount option specified.
3322 	 */
3323 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3324 
3325 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3326 			   &journal_devnum, &journal_ioprio, 0)) {
3327 		ext4_msg(sb, KERN_WARNING,
3328 			 "failed to parse options in superblock: %s",
3329 			 sbi->s_es->s_mount_opts);
3330 	}
3331 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3332 	if (!parse_options((char *) data, sb, &journal_devnum,
3333 			   &journal_ioprio, 0))
3334 		goto failed_mount;
3335 
3336 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3337 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3338 			    "with data=journal disables delayed "
3339 			    "allocation and O_DIRECT support!\n");
3340 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3341 			ext4_msg(sb, KERN_ERR, "can't mount with "
3342 				 "both data=journal and delalloc");
3343 			goto failed_mount;
3344 		}
3345 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3346 			ext4_msg(sb, KERN_ERR, "can't mount with "
3347 				 "both data=journal and dioread_nolock");
3348 			goto failed_mount;
3349 		}
3350 		if (test_opt(sb, DAX)) {
3351 			ext4_msg(sb, KERN_ERR, "can't mount with "
3352 				 "both data=journal and dax");
3353 			goto failed_mount;
3354 		}
3355 		if (test_opt(sb, DELALLOC))
3356 			clear_opt(sb, DELALLOC);
3357 	} else {
3358 		sb->s_iflags |= SB_I_CGROUPWB;
3359 	}
3360 
3361 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3362 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3363 
3364 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3365 	    (ext4_has_compat_features(sb) ||
3366 	     ext4_has_ro_compat_features(sb) ||
3367 	     ext4_has_incompat_features(sb)))
3368 		ext4_msg(sb, KERN_WARNING,
3369 		       "feature flags set on rev 0 fs, "
3370 		       "running e2fsck is recommended");
3371 
3372 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3373 		set_opt2(sb, HURD_COMPAT);
3374 		if (ext4_has_feature_64bit(sb)) {
3375 			ext4_msg(sb, KERN_ERR,
3376 				 "The Hurd can't support 64-bit file systems");
3377 			goto failed_mount;
3378 		}
3379 	}
3380 
3381 	if (IS_EXT2_SB(sb)) {
3382 		if (ext2_feature_set_ok(sb))
3383 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3384 				 "using the ext4 subsystem");
3385 		else {
3386 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3387 				 "to feature incompatibilities");
3388 			goto failed_mount;
3389 		}
3390 	}
3391 
3392 	if (IS_EXT3_SB(sb)) {
3393 		if (ext3_feature_set_ok(sb))
3394 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3395 				 "using the ext4 subsystem");
3396 		else {
3397 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3398 				 "to feature incompatibilities");
3399 			goto failed_mount;
3400 		}
3401 	}
3402 
3403 	/*
3404 	 * Check feature flags regardless of the revision level, since we
3405 	 * previously didn't change the revision level when setting the flags,
3406 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3407 	 */
3408 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3409 		goto failed_mount;
3410 
3411 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3412 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3413 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3414 		ext4_msg(sb, KERN_ERR,
3415 		       "Unsupported filesystem blocksize %d", blocksize);
3416 		goto failed_mount;
3417 	}
3418 
3419 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3420 		err = bdev_dax_supported(sb, blocksize);
3421 		if (err)
3422 			goto failed_mount;
3423 	}
3424 
3425 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3426 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3427 			 es->s_encryption_level);
3428 		goto failed_mount;
3429 	}
3430 
3431 	if (sb->s_blocksize != blocksize) {
3432 		/* Validate the filesystem blocksize */
3433 		if (!sb_set_blocksize(sb, blocksize)) {
3434 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3435 					blocksize);
3436 			goto failed_mount;
3437 		}
3438 
3439 		brelse(bh);
3440 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3441 		offset = do_div(logical_sb_block, blocksize);
3442 		bh = sb_bread_unmovable(sb, logical_sb_block);
3443 		if (!bh) {
3444 			ext4_msg(sb, KERN_ERR,
3445 			       "Can't read superblock on 2nd try");
3446 			goto failed_mount;
3447 		}
3448 		es = (struct ext4_super_block *)(bh->b_data + offset);
3449 		sbi->s_es = es;
3450 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3451 			ext4_msg(sb, KERN_ERR,
3452 			       "Magic mismatch, very weird!");
3453 			goto failed_mount;
3454 		}
3455 	}
3456 
3457 	has_huge_files = ext4_has_feature_huge_file(sb);
3458 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3459 						      has_huge_files);
3460 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3461 
3462 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3463 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3464 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3465 	} else {
3466 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3467 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3468 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3469 		    (!is_power_of_2(sbi->s_inode_size)) ||
3470 		    (sbi->s_inode_size > blocksize)) {
3471 			ext4_msg(sb, KERN_ERR,
3472 			       "unsupported inode size: %d",
3473 			       sbi->s_inode_size);
3474 			goto failed_mount;
3475 		}
3476 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3477 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3478 	}
3479 
3480 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3481 	if (ext4_has_feature_64bit(sb)) {
3482 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3483 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3484 		    !is_power_of_2(sbi->s_desc_size)) {
3485 			ext4_msg(sb, KERN_ERR,
3486 			       "unsupported descriptor size %lu",
3487 			       sbi->s_desc_size);
3488 			goto failed_mount;
3489 		}
3490 	} else
3491 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3492 
3493 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3494 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3495 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3496 		goto cantfind_ext4;
3497 
3498 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3499 	if (sbi->s_inodes_per_block == 0)
3500 		goto cantfind_ext4;
3501 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3502 					sbi->s_inodes_per_block;
3503 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3504 	sbi->s_sbh = bh;
3505 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3506 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3507 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3508 
3509 	for (i = 0; i < 4; i++)
3510 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3511 	sbi->s_def_hash_version = es->s_def_hash_version;
3512 	if (ext4_has_feature_dir_index(sb)) {
3513 		i = le32_to_cpu(es->s_flags);
3514 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3515 			sbi->s_hash_unsigned = 3;
3516 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3517 #ifdef __CHAR_UNSIGNED__
3518 			if (!(sb->s_flags & MS_RDONLY))
3519 				es->s_flags |=
3520 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3521 			sbi->s_hash_unsigned = 3;
3522 #else
3523 			if (!(sb->s_flags & MS_RDONLY))
3524 				es->s_flags |=
3525 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3526 #endif
3527 		}
3528 	}
3529 
3530 	/* Handle clustersize */
3531 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3532 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3533 	if (has_bigalloc) {
3534 		if (clustersize < blocksize) {
3535 			ext4_msg(sb, KERN_ERR,
3536 				 "cluster size (%d) smaller than "
3537 				 "block size (%d)", clustersize, blocksize);
3538 			goto failed_mount;
3539 		}
3540 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3541 			le32_to_cpu(es->s_log_block_size);
3542 		sbi->s_clusters_per_group =
3543 			le32_to_cpu(es->s_clusters_per_group);
3544 		if (sbi->s_clusters_per_group > blocksize * 8) {
3545 			ext4_msg(sb, KERN_ERR,
3546 				 "#clusters per group too big: %lu",
3547 				 sbi->s_clusters_per_group);
3548 			goto failed_mount;
3549 		}
3550 		if (sbi->s_blocks_per_group !=
3551 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3552 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3553 				 "clusters per group (%lu) inconsistent",
3554 				 sbi->s_blocks_per_group,
3555 				 sbi->s_clusters_per_group);
3556 			goto failed_mount;
3557 		}
3558 	} else {
3559 		if (clustersize != blocksize) {
3560 			ext4_warning(sb, "fragment/cluster size (%d) != "
3561 				     "block size (%d)", clustersize,
3562 				     blocksize);
3563 			clustersize = blocksize;
3564 		}
3565 		if (sbi->s_blocks_per_group > blocksize * 8) {
3566 			ext4_msg(sb, KERN_ERR,
3567 				 "#blocks per group too big: %lu",
3568 				 sbi->s_blocks_per_group);
3569 			goto failed_mount;
3570 		}
3571 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3572 		sbi->s_cluster_bits = 0;
3573 	}
3574 	sbi->s_cluster_ratio = clustersize / blocksize;
3575 
3576 	if (sbi->s_inodes_per_group > blocksize * 8) {
3577 		ext4_msg(sb, KERN_ERR,
3578 		       "#inodes per group too big: %lu",
3579 		       sbi->s_inodes_per_group);
3580 		goto failed_mount;
3581 	}
3582 
3583 	/* Do we have standard group size of clustersize * 8 blocks ? */
3584 	if (sbi->s_blocks_per_group == clustersize << 3)
3585 		set_opt2(sb, STD_GROUP_SIZE);
3586 
3587 	/*
3588 	 * Test whether we have more sectors than will fit in sector_t,
3589 	 * and whether the max offset is addressable by the page cache.
3590 	 */
3591 	err = generic_check_addressable(sb->s_blocksize_bits,
3592 					ext4_blocks_count(es));
3593 	if (err) {
3594 		ext4_msg(sb, KERN_ERR, "filesystem"
3595 			 " too large to mount safely on this system");
3596 		if (sizeof(sector_t) < 8)
3597 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3598 		goto failed_mount;
3599 	}
3600 
3601 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3602 		goto cantfind_ext4;
3603 
3604 	/* check blocks count against device size */
3605 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3606 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3607 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3608 		       "exceeds size of device (%llu blocks)",
3609 		       ext4_blocks_count(es), blocks_count);
3610 		goto failed_mount;
3611 	}
3612 
3613 	/*
3614 	 * It makes no sense for the first data block to be beyond the end
3615 	 * of the filesystem.
3616 	 */
3617 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3618 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3619 			 "block %u is beyond end of filesystem (%llu)",
3620 			 le32_to_cpu(es->s_first_data_block),
3621 			 ext4_blocks_count(es));
3622 		goto failed_mount;
3623 	}
3624 	blocks_count = (ext4_blocks_count(es) -
3625 			le32_to_cpu(es->s_first_data_block) +
3626 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3627 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3628 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3629 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3630 		       "(block count %llu, first data block %u, "
3631 		       "blocks per group %lu)", sbi->s_groups_count,
3632 		       ext4_blocks_count(es),
3633 		       le32_to_cpu(es->s_first_data_block),
3634 		       EXT4_BLOCKS_PER_GROUP(sb));
3635 		goto failed_mount;
3636 	}
3637 	sbi->s_groups_count = blocks_count;
3638 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3639 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3640 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3641 		   EXT4_DESC_PER_BLOCK(sb);
3642 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3643 					  sizeof(struct buffer_head *),
3644 					  GFP_KERNEL);
3645 	if (sbi->s_group_desc == NULL) {
3646 		ext4_msg(sb, KERN_ERR, "not enough memory");
3647 		ret = -ENOMEM;
3648 		goto failed_mount;
3649 	}
3650 
3651 	bgl_lock_init(sbi->s_blockgroup_lock);
3652 
3653 	for (i = 0; i < db_count; i++) {
3654 		block = descriptor_loc(sb, logical_sb_block, i);
3655 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3656 		if (!sbi->s_group_desc[i]) {
3657 			ext4_msg(sb, KERN_ERR,
3658 			       "can't read group descriptor %d", i);
3659 			db_count = i;
3660 			goto failed_mount2;
3661 		}
3662 	}
3663 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3664 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3665 		ret = -EFSCORRUPTED;
3666 		goto failed_mount2;
3667 	}
3668 
3669 	sbi->s_gdb_count = db_count;
3670 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3671 	spin_lock_init(&sbi->s_next_gen_lock);
3672 
3673 	setup_timer(&sbi->s_err_report, print_daily_error_info,
3674 		(unsigned long) sb);
3675 
3676 	/* Register extent status tree shrinker */
3677 	if (ext4_es_register_shrinker(sbi))
3678 		goto failed_mount3;
3679 
3680 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3681 	sbi->s_extent_max_zeroout_kb = 32;
3682 
3683 	/*
3684 	 * set up enough so that it can read an inode
3685 	 */
3686 	sb->s_op = &ext4_sops;
3687 	sb->s_export_op = &ext4_export_ops;
3688 	sb->s_xattr = ext4_xattr_handlers;
3689 #ifdef CONFIG_QUOTA
3690 	sb->dq_op = &ext4_quota_operations;
3691 	if (ext4_has_feature_quota(sb))
3692 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
3693 	else
3694 		sb->s_qcop = &ext4_qctl_operations;
3695 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3696 #endif
3697 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3698 
3699 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3700 	mutex_init(&sbi->s_orphan_lock);
3701 
3702 	sb->s_root = NULL;
3703 
3704 	needs_recovery = (es->s_last_orphan != 0 ||
3705 			  ext4_has_feature_journal_needs_recovery(sb));
3706 
3707 	if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3708 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3709 			goto failed_mount3a;
3710 
3711 	/*
3712 	 * The first inode we look at is the journal inode.  Don't try
3713 	 * root first: it may be modified in the journal!
3714 	 */
3715 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3716 		if (ext4_load_journal(sb, es, journal_devnum))
3717 			goto failed_mount3a;
3718 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3719 		   ext4_has_feature_journal_needs_recovery(sb)) {
3720 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3721 		       "suppressed and not mounted read-only");
3722 		goto failed_mount_wq;
3723 	} else {
3724 		/* Nojournal mode, all journal mount options are illegal */
3725 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3726 			ext4_msg(sb, KERN_ERR, "can't mount with "
3727 				 "journal_checksum, fs mounted w/o journal");
3728 			goto failed_mount_wq;
3729 		}
3730 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3731 			ext4_msg(sb, KERN_ERR, "can't mount with "
3732 				 "journal_async_commit, fs mounted w/o journal");
3733 			goto failed_mount_wq;
3734 		}
3735 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3736 			ext4_msg(sb, KERN_ERR, "can't mount with "
3737 				 "commit=%lu, fs mounted w/o journal",
3738 				 sbi->s_commit_interval / HZ);
3739 			goto failed_mount_wq;
3740 		}
3741 		if (EXT4_MOUNT_DATA_FLAGS &
3742 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3743 			ext4_msg(sb, KERN_ERR, "can't mount with "
3744 				 "data=, fs mounted w/o journal");
3745 			goto failed_mount_wq;
3746 		}
3747 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3748 		clear_opt(sb, JOURNAL_CHECKSUM);
3749 		clear_opt(sb, DATA_FLAGS);
3750 		sbi->s_journal = NULL;
3751 		needs_recovery = 0;
3752 		goto no_journal;
3753 	}
3754 
3755 	if (ext4_has_feature_64bit(sb) &&
3756 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3757 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3758 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3759 		goto failed_mount_wq;
3760 	}
3761 
3762 	if (!set_journal_csum_feature_set(sb)) {
3763 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3764 			 "feature set");
3765 		goto failed_mount_wq;
3766 	}
3767 
3768 	/* We have now updated the journal if required, so we can
3769 	 * validate the data journaling mode. */
3770 	switch (test_opt(sb, DATA_FLAGS)) {
3771 	case 0:
3772 		/* No mode set, assume a default based on the journal
3773 		 * capabilities: ORDERED_DATA if the journal can
3774 		 * cope, else JOURNAL_DATA
3775 		 */
3776 		if (jbd2_journal_check_available_features
3777 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3778 			set_opt(sb, ORDERED_DATA);
3779 		else
3780 			set_opt(sb, JOURNAL_DATA);
3781 		break;
3782 
3783 	case EXT4_MOUNT_ORDERED_DATA:
3784 	case EXT4_MOUNT_WRITEBACK_DATA:
3785 		if (!jbd2_journal_check_available_features
3786 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3787 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3788 			       "requested data journaling mode");
3789 			goto failed_mount_wq;
3790 		}
3791 	default:
3792 		break;
3793 	}
3794 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3795 
3796 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3797 
3798 no_journal:
3799 	sbi->s_mb_cache = ext4_xattr_create_cache();
3800 	if (!sbi->s_mb_cache) {
3801 		ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
3802 		goto failed_mount_wq;
3803 	}
3804 
3805 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
3806 	    (blocksize != PAGE_SIZE)) {
3807 		ext4_msg(sb, KERN_ERR,
3808 			 "Unsupported blocksize for fs encryption");
3809 		goto failed_mount_wq;
3810 	}
3811 
3812 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
3813 	    !ext4_has_feature_encrypt(sb)) {
3814 		ext4_set_feature_encrypt(sb);
3815 		ext4_commit_super(sb, 1);
3816 	}
3817 
3818 	/*
3819 	 * Get the # of file system overhead blocks from the
3820 	 * superblock if present.
3821 	 */
3822 	if (es->s_overhead_clusters)
3823 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3824 	else {
3825 		err = ext4_calculate_overhead(sb);
3826 		if (err)
3827 			goto failed_mount_wq;
3828 	}
3829 
3830 	/*
3831 	 * The maximum number of concurrent works can be high and
3832 	 * concurrency isn't really necessary.  Limit it to 1.
3833 	 */
3834 	EXT4_SB(sb)->rsv_conversion_wq =
3835 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3836 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
3837 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3838 		ret = -ENOMEM;
3839 		goto failed_mount4;
3840 	}
3841 
3842 	/*
3843 	 * The jbd2_journal_load will have done any necessary log recovery,
3844 	 * so we can safely mount the rest of the filesystem now.
3845 	 */
3846 
3847 	root = ext4_iget(sb, EXT4_ROOT_INO);
3848 	if (IS_ERR(root)) {
3849 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3850 		ret = PTR_ERR(root);
3851 		root = NULL;
3852 		goto failed_mount4;
3853 	}
3854 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3855 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3856 		iput(root);
3857 		goto failed_mount4;
3858 	}
3859 	sb->s_root = d_make_root(root);
3860 	if (!sb->s_root) {
3861 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3862 		ret = -ENOMEM;
3863 		goto failed_mount4;
3864 	}
3865 
3866 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3867 		sb->s_flags |= MS_RDONLY;
3868 
3869 	/* determine the minimum size of new large inodes, if present */
3870 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3871 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3872 						     EXT4_GOOD_OLD_INODE_SIZE;
3873 		if (ext4_has_feature_extra_isize(sb)) {
3874 			if (sbi->s_want_extra_isize <
3875 			    le16_to_cpu(es->s_want_extra_isize))
3876 				sbi->s_want_extra_isize =
3877 					le16_to_cpu(es->s_want_extra_isize);
3878 			if (sbi->s_want_extra_isize <
3879 			    le16_to_cpu(es->s_min_extra_isize))
3880 				sbi->s_want_extra_isize =
3881 					le16_to_cpu(es->s_min_extra_isize);
3882 		}
3883 	}
3884 	/* Check if enough inode space is available */
3885 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3886 							sbi->s_inode_size) {
3887 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3888 						       EXT4_GOOD_OLD_INODE_SIZE;
3889 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
3890 			 "available");
3891 	}
3892 
3893 	ext4_set_resv_clusters(sb);
3894 
3895 	err = ext4_setup_system_zone(sb);
3896 	if (err) {
3897 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
3898 			 "zone (%d)", err);
3899 		goto failed_mount4a;
3900 	}
3901 
3902 	ext4_ext_init(sb);
3903 	err = ext4_mb_init(sb);
3904 	if (err) {
3905 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3906 			 err);
3907 		goto failed_mount5;
3908 	}
3909 
3910 	block = ext4_count_free_clusters(sb);
3911 	ext4_free_blocks_count_set(sbi->s_es,
3912 				   EXT4_C2B(sbi, block));
3913 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
3914 				  GFP_KERNEL);
3915 	if (!err) {
3916 		unsigned long freei = ext4_count_free_inodes(sb);
3917 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
3918 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
3919 					  GFP_KERNEL);
3920 	}
3921 	if (!err)
3922 		err = percpu_counter_init(&sbi->s_dirs_counter,
3923 					  ext4_count_dirs(sb), GFP_KERNEL);
3924 	if (!err)
3925 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
3926 					  GFP_KERNEL);
3927 	if (!err)
3928 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
3929 
3930 	if (err) {
3931 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3932 		goto failed_mount6;
3933 	}
3934 
3935 	if (ext4_has_feature_flex_bg(sb))
3936 		if (!ext4_fill_flex_info(sb)) {
3937 			ext4_msg(sb, KERN_ERR,
3938 			       "unable to initialize "
3939 			       "flex_bg meta info!");
3940 			goto failed_mount6;
3941 		}
3942 
3943 	err = ext4_register_li_request(sb, first_not_zeroed);
3944 	if (err)
3945 		goto failed_mount6;
3946 
3947 	err = ext4_register_sysfs(sb);
3948 	if (err)
3949 		goto failed_mount7;
3950 
3951 #ifdef CONFIG_QUOTA
3952 	/* Enable quota usage during mount. */
3953 	if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
3954 		err = ext4_enable_quotas(sb);
3955 		if (err)
3956 			goto failed_mount8;
3957 	}
3958 #endif  /* CONFIG_QUOTA */
3959 
3960 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3961 	ext4_orphan_cleanup(sb, es);
3962 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3963 	if (needs_recovery) {
3964 		ext4_msg(sb, KERN_INFO, "recovery complete");
3965 		ext4_mark_recovery_complete(sb, es);
3966 	}
3967 	if (EXT4_SB(sb)->s_journal) {
3968 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3969 			descr = " journalled data mode";
3970 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3971 			descr = " ordered data mode";
3972 		else
3973 			descr = " writeback data mode";
3974 	} else
3975 		descr = "out journal";
3976 
3977 	if (test_opt(sb, DISCARD)) {
3978 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
3979 		if (!blk_queue_discard(q))
3980 			ext4_msg(sb, KERN_WARNING,
3981 				 "mounting with \"discard\" option, but "
3982 				 "the device does not support discard");
3983 	}
3984 
3985 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
3986 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3987 			 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3988 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3989 
3990 	if (es->s_error_count)
3991 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3992 
3993 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
3994 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
3995 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
3996 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
3997 
3998 	kfree(orig_data);
3999 	return 0;
4000 
4001 cantfind_ext4:
4002 	if (!silent)
4003 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4004 	goto failed_mount;
4005 
4006 #ifdef CONFIG_QUOTA
4007 failed_mount8:
4008 	ext4_unregister_sysfs(sb);
4009 #endif
4010 failed_mount7:
4011 	ext4_unregister_li_request(sb);
4012 failed_mount6:
4013 	ext4_mb_release(sb);
4014 	if (sbi->s_flex_groups)
4015 		kvfree(sbi->s_flex_groups);
4016 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4017 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4018 	percpu_counter_destroy(&sbi->s_dirs_counter);
4019 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4020 failed_mount5:
4021 	ext4_ext_release(sb);
4022 	ext4_release_system_zone(sb);
4023 failed_mount4a:
4024 	dput(sb->s_root);
4025 	sb->s_root = NULL;
4026 failed_mount4:
4027 	ext4_msg(sb, KERN_ERR, "mount failed");
4028 	if (EXT4_SB(sb)->rsv_conversion_wq)
4029 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4030 failed_mount_wq:
4031 	if (sbi->s_mb_cache) {
4032 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
4033 		sbi->s_mb_cache = NULL;
4034 	}
4035 	if (sbi->s_journal) {
4036 		jbd2_journal_destroy(sbi->s_journal);
4037 		sbi->s_journal = NULL;
4038 	}
4039 failed_mount3a:
4040 	ext4_es_unregister_shrinker(sbi);
4041 failed_mount3:
4042 	del_timer_sync(&sbi->s_err_report);
4043 	if (sbi->s_mmp_tsk)
4044 		kthread_stop(sbi->s_mmp_tsk);
4045 failed_mount2:
4046 	for (i = 0; i < db_count; i++)
4047 		brelse(sbi->s_group_desc[i]);
4048 	kvfree(sbi->s_group_desc);
4049 failed_mount:
4050 	if (sbi->s_chksum_driver)
4051 		crypto_free_shash(sbi->s_chksum_driver);
4052 #ifdef CONFIG_QUOTA
4053 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4054 		kfree(sbi->s_qf_names[i]);
4055 #endif
4056 	ext4_blkdev_remove(sbi);
4057 	brelse(bh);
4058 out_fail:
4059 	sb->s_fs_info = NULL;
4060 	kfree(sbi->s_blockgroup_lock);
4061 	kfree(sbi);
4062 out_free_orig:
4063 	kfree(orig_data);
4064 	return err ? err : ret;
4065 }
4066 
4067 /*
4068  * Setup any per-fs journal parameters now.  We'll do this both on
4069  * initial mount, once the journal has been initialised but before we've
4070  * done any recovery; and again on any subsequent remount.
4071  */
4072 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4073 {
4074 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4075 
4076 	journal->j_commit_interval = sbi->s_commit_interval;
4077 	journal->j_min_batch_time = sbi->s_min_batch_time;
4078 	journal->j_max_batch_time = sbi->s_max_batch_time;
4079 
4080 	write_lock(&journal->j_state_lock);
4081 	if (test_opt(sb, BARRIER))
4082 		journal->j_flags |= JBD2_BARRIER;
4083 	else
4084 		journal->j_flags &= ~JBD2_BARRIER;
4085 	if (test_opt(sb, DATA_ERR_ABORT))
4086 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4087 	else
4088 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4089 	write_unlock(&journal->j_state_lock);
4090 }
4091 
4092 static journal_t *ext4_get_journal(struct super_block *sb,
4093 				   unsigned int journal_inum)
4094 {
4095 	struct inode *journal_inode;
4096 	journal_t *journal;
4097 
4098 	BUG_ON(!ext4_has_feature_journal(sb));
4099 
4100 	/* First, test for the existence of a valid inode on disk.  Bad
4101 	 * things happen if we iget() an unused inode, as the subsequent
4102 	 * iput() will try to delete it. */
4103 
4104 	journal_inode = ext4_iget(sb, journal_inum);
4105 	if (IS_ERR(journal_inode)) {
4106 		ext4_msg(sb, KERN_ERR, "no journal found");
4107 		return NULL;
4108 	}
4109 	if (!journal_inode->i_nlink) {
4110 		make_bad_inode(journal_inode);
4111 		iput(journal_inode);
4112 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4113 		return NULL;
4114 	}
4115 
4116 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4117 		  journal_inode, journal_inode->i_size);
4118 	if (!S_ISREG(journal_inode->i_mode)) {
4119 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4120 		iput(journal_inode);
4121 		return NULL;
4122 	}
4123 
4124 	journal = jbd2_journal_init_inode(journal_inode);
4125 	if (!journal) {
4126 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4127 		iput(journal_inode);
4128 		return NULL;
4129 	}
4130 	journal->j_private = sb;
4131 	ext4_init_journal_params(sb, journal);
4132 	return journal;
4133 }
4134 
4135 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4136 				       dev_t j_dev)
4137 {
4138 	struct buffer_head *bh;
4139 	journal_t *journal;
4140 	ext4_fsblk_t start;
4141 	ext4_fsblk_t len;
4142 	int hblock, blocksize;
4143 	ext4_fsblk_t sb_block;
4144 	unsigned long offset;
4145 	struct ext4_super_block *es;
4146 	struct block_device *bdev;
4147 
4148 	BUG_ON(!ext4_has_feature_journal(sb));
4149 
4150 	bdev = ext4_blkdev_get(j_dev, sb);
4151 	if (bdev == NULL)
4152 		return NULL;
4153 
4154 	blocksize = sb->s_blocksize;
4155 	hblock = bdev_logical_block_size(bdev);
4156 	if (blocksize < hblock) {
4157 		ext4_msg(sb, KERN_ERR,
4158 			"blocksize too small for journal device");
4159 		goto out_bdev;
4160 	}
4161 
4162 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4163 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4164 	set_blocksize(bdev, blocksize);
4165 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4166 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4167 		       "external journal");
4168 		goto out_bdev;
4169 	}
4170 
4171 	es = (struct ext4_super_block *) (bh->b_data + offset);
4172 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4173 	    !(le32_to_cpu(es->s_feature_incompat) &
4174 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4175 		ext4_msg(sb, KERN_ERR, "external journal has "
4176 					"bad superblock");
4177 		brelse(bh);
4178 		goto out_bdev;
4179 	}
4180 
4181 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4182 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4183 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4184 		ext4_msg(sb, KERN_ERR, "external journal has "
4185 				       "corrupt superblock");
4186 		brelse(bh);
4187 		goto out_bdev;
4188 	}
4189 
4190 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4191 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4192 		brelse(bh);
4193 		goto out_bdev;
4194 	}
4195 
4196 	len = ext4_blocks_count(es);
4197 	start = sb_block + 1;
4198 	brelse(bh);	/* we're done with the superblock */
4199 
4200 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4201 					start, len, blocksize);
4202 	if (!journal) {
4203 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4204 		goto out_bdev;
4205 	}
4206 	journal->j_private = sb;
4207 	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4208 	wait_on_buffer(journal->j_sb_buffer);
4209 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4210 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4211 		goto out_journal;
4212 	}
4213 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4214 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4215 					"user (unsupported) - %d",
4216 			be32_to_cpu(journal->j_superblock->s_nr_users));
4217 		goto out_journal;
4218 	}
4219 	EXT4_SB(sb)->journal_bdev = bdev;
4220 	ext4_init_journal_params(sb, journal);
4221 	return journal;
4222 
4223 out_journal:
4224 	jbd2_journal_destroy(journal);
4225 out_bdev:
4226 	ext4_blkdev_put(bdev);
4227 	return NULL;
4228 }
4229 
4230 static int ext4_load_journal(struct super_block *sb,
4231 			     struct ext4_super_block *es,
4232 			     unsigned long journal_devnum)
4233 {
4234 	journal_t *journal;
4235 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4236 	dev_t journal_dev;
4237 	int err = 0;
4238 	int really_read_only;
4239 
4240 	BUG_ON(!ext4_has_feature_journal(sb));
4241 
4242 	if (journal_devnum &&
4243 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4244 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4245 			"numbers have changed");
4246 		journal_dev = new_decode_dev(journal_devnum);
4247 	} else
4248 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4249 
4250 	really_read_only = bdev_read_only(sb->s_bdev);
4251 
4252 	/*
4253 	 * Are we loading a blank journal or performing recovery after a
4254 	 * crash?  For recovery, we need to check in advance whether we
4255 	 * can get read-write access to the device.
4256 	 */
4257 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4258 		if (sb->s_flags & MS_RDONLY) {
4259 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4260 					"required on readonly filesystem");
4261 			if (really_read_only) {
4262 				ext4_msg(sb, KERN_ERR, "write access "
4263 					"unavailable, cannot proceed");
4264 				return -EROFS;
4265 			}
4266 			ext4_msg(sb, KERN_INFO, "write access will "
4267 			       "be enabled during recovery");
4268 		}
4269 	}
4270 
4271 	if (journal_inum && journal_dev) {
4272 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4273 		       "and inode journals!");
4274 		return -EINVAL;
4275 	}
4276 
4277 	if (journal_inum) {
4278 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4279 			return -EINVAL;
4280 	} else {
4281 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4282 			return -EINVAL;
4283 	}
4284 
4285 	if (!(journal->j_flags & JBD2_BARRIER))
4286 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4287 
4288 	if (!ext4_has_feature_journal_needs_recovery(sb))
4289 		err = jbd2_journal_wipe(journal, !really_read_only);
4290 	if (!err) {
4291 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4292 		if (save)
4293 			memcpy(save, ((char *) es) +
4294 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4295 		err = jbd2_journal_load(journal);
4296 		if (save)
4297 			memcpy(((char *) es) + EXT4_S_ERR_START,
4298 			       save, EXT4_S_ERR_LEN);
4299 		kfree(save);
4300 	}
4301 
4302 	if (err) {
4303 		ext4_msg(sb, KERN_ERR, "error loading journal");
4304 		jbd2_journal_destroy(journal);
4305 		return err;
4306 	}
4307 
4308 	EXT4_SB(sb)->s_journal = journal;
4309 	ext4_clear_journal_err(sb, es);
4310 
4311 	if (!really_read_only && journal_devnum &&
4312 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4313 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4314 
4315 		/* Make sure we flush the recovery flag to disk. */
4316 		ext4_commit_super(sb, 1);
4317 	}
4318 
4319 	return 0;
4320 }
4321 
4322 static int ext4_commit_super(struct super_block *sb, int sync)
4323 {
4324 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4325 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4326 	int error = 0;
4327 
4328 	if (!sbh || block_device_ejected(sb))
4329 		return error;
4330 	if (buffer_write_io_error(sbh)) {
4331 		/*
4332 		 * Oh, dear.  A previous attempt to write the
4333 		 * superblock failed.  This could happen because the
4334 		 * USB device was yanked out.  Or it could happen to
4335 		 * be a transient write error and maybe the block will
4336 		 * be remapped.  Nothing we can do but to retry the
4337 		 * write and hope for the best.
4338 		 */
4339 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4340 		       "superblock detected");
4341 		clear_buffer_write_io_error(sbh);
4342 		set_buffer_uptodate(sbh);
4343 	}
4344 	/*
4345 	 * If the file system is mounted read-only, don't update the
4346 	 * superblock write time.  This avoids updating the superblock
4347 	 * write time when we are mounting the root file system
4348 	 * read/only but we need to replay the journal; at that point,
4349 	 * for people who are east of GMT and who make their clock
4350 	 * tick in localtime for Windows bug-for-bug compatibility,
4351 	 * the clock is set in the future, and this will cause e2fsck
4352 	 * to complain and force a full file system check.
4353 	 */
4354 	if (!(sb->s_flags & MS_RDONLY))
4355 		es->s_wtime = cpu_to_le32(get_seconds());
4356 	if (sb->s_bdev->bd_part)
4357 		es->s_kbytes_written =
4358 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4359 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4360 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4361 	else
4362 		es->s_kbytes_written =
4363 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4364 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4365 		ext4_free_blocks_count_set(es,
4366 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4367 				&EXT4_SB(sb)->s_freeclusters_counter)));
4368 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4369 		es->s_free_inodes_count =
4370 			cpu_to_le32(percpu_counter_sum_positive(
4371 				&EXT4_SB(sb)->s_freeinodes_counter));
4372 	BUFFER_TRACE(sbh, "marking dirty");
4373 	ext4_superblock_csum_set(sb);
4374 	mark_buffer_dirty(sbh);
4375 	if (sync) {
4376 		error = __sync_dirty_buffer(sbh,
4377 			test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4378 		if (error)
4379 			return error;
4380 
4381 		error = buffer_write_io_error(sbh);
4382 		if (error) {
4383 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4384 			       "superblock");
4385 			clear_buffer_write_io_error(sbh);
4386 			set_buffer_uptodate(sbh);
4387 		}
4388 	}
4389 	return error;
4390 }
4391 
4392 /*
4393  * Have we just finished recovery?  If so, and if we are mounting (or
4394  * remounting) the filesystem readonly, then we will end up with a
4395  * consistent fs on disk.  Record that fact.
4396  */
4397 static void ext4_mark_recovery_complete(struct super_block *sb,
4398 					struct ext4_super_block *es)
4399 {
4400 	journal_t *journal = EXT4_SB(sb)->s_journal;
4401 
4402 	if (!ext4_has_feature_journal(sb)) {
4403 		BUG_ON(journal != NULL);
4404 		return;
4405 	}
4406 	jbd2_journal_lock_updates(journal);
4407 	if (jbd2_journal_flush(journal) < 0)
4408 		goto out;
4409 
4410 	if (ext4_has_feature_journal_needs_recovery(sb) &&
4411 	    sb->s_flags & MS_RDONLY) {
4412 		ext4_clear_feature_journal_needs_recovery(sb);
4413 		ext4_commit_super(sb, 1);
4414 	}
4415 
4416 out:
4417 	jbd2_journal_unlock_updates(journal);
4418 }
4419 
4420 /*
4421  * If we are mounting (or read-write remounting) a filesystem whose journal
4422  * has recorded an error from a previous lifetime, move that error to the
4423  * main filesystem now.
4424  */
4425 static void ext4_clear_journal_err(struct super_block *sb,
4426 				   struct ext4_super_block *es)
4427 {
4428 	journal_t *journal;
4429 	int j_errno;
4430 	const char *errstr;
4431 
4432 	BUG_ON(!ext4_has_feature_journal(sb));
4433 
4434 	journal = EXT4_SB(sb)->s_journal;
4435 
4436 	/*
4437 	 * Now check for any error status which may have been recorded in the
4438 	 * journal by a prior ext4_error() or ext4_abort()
4439 	 */
4440 
4441 	j_errno = jbd2_journal_errno(journal);
4442 	if (j_errno) {
4443 		char nbuf[16];
4444 
4445 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4446 		ext4_warning(sb, "Filesystem error recorded "
4447 			     "from previous mount: %s", errstr);
4448 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4449 
4450 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4451 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4452 		ext4_commit_super(sb, 1);
4453 
4454 		jbd2_journal_clear_err(journal);
4455 		jbd2_journal_update_sb_errno(journal);
4456 	}
4457 }
4458 
4459 /*
4460  * Force the running and committing transactions to commit,
4461  * and wait on the commit.
4462  */
4463 int ext4_force_commit(struct super_block *sb)
4464 {
4465 	journal_t *journal;
4466 
4467 	if (sb->s_flags & MS_RDONLY)
4468 		return 0;
4469 
4470 	journal = EXT4_SB(sb)->s_journal;
4471 	return ext4_journal_force_commit(journal);
4472 }
4473 
4474 static int ext4_sync_fs(struct super_block *sb, int wait)
4475 {
4476 	int ret = 0;
4477 	tid_t target;
4478 	bool needs_barrier = false;
4479 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4480 
4481 	trace_ext4_sync_fs(sb, wait);
4482 	flush_workqueue(sbi->rsv_conversion_wq);
4483 	/*
4484 	 * Writeback quota in non-journalled quota case - journalled quota has
4485 	 * no dirty dquots
4486 	 */
4487 	dquot_writeback_dquots(sb, -1);
4488 	/*
4489 	 * Data writeback is possible w/o journal transaction, so barrier must
4490 	 * being sent at the end of the function. But we can skip it if
4491 	 * transaction_commit will do it for us.
4492 	 */
4493 	if (sbi->s_journal) {
4494 		target = jbd2_get_latest_transaction(sbi->s_journal);
4495 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4496 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4497 			needs_barrier = true;
4498 
4499 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4500 			if (wait)
4501 				ret = jbd2_log_wait_commit(sbi->s_journal,
4502 							   target);
4503 		}
4504 	} else if (wait && test_opt(sb, BARRIER))
4505 		needs_barrier = true;
4506 	if (needs_barrier) {
4507 		int err;
4508 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4509 		if (!ret)
4510 			ret = err;
4511 	}
4512 
4513 	return ret;
4514 }
4515 
4516 /*
4517  * LVM calls this function before a (read-only) snapshot is created.  This
4518  * gives us a chance to flush the journal completely and mark the fs clean.
4519  *
4520  * Note that only this function cannot bring a filesystem to be in a clean
4521  * state independently. It relies on upper layer to stop all data & metadata
4522  * modifications.
4523  */
4524 static int ext4_freeze(struct super_block *sb)
4525 {
4526 	int error = 0;
4527 	journal_t *journal;
4528 
4529 	if (sb->s_flags & MS_RDONLY)
4530 		return 0;
4531 
4532 	journal = EXT4_SB(sb)->s_journal;
4533 
4534 	if (journal) {
4535 		/* Now we set up the journal barrier. */
4536 		jbd2_journal_lock_updates(journal);
4537 
4538 		/*
4539 		 * Don't clear the needs_recovery flag if we failed to
4540 		 * flush the journal.
4541 		 */
4542 		error = jbd2_journal_flush(journal);
4543 		if (error < 0)
4544 			goto out;
4545 
4546 		/* Journal blocked and flushed, clear needs_recovery flag. */
4547 		ext4_clear_feature_journal_needs_recovery(sb);
4548 	}
4549 
4550 	error = ext4_commit_super(sb, 1);
4551 out:
4552 	if (journal)
4553 		/* we rely on upper layer to stop further updates */
4554 		jbd2_journal_unlock_updates(journal);
4555 	return error;
4556 }
4557 
4558 /*
4559  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4560  * flag here, even though the filesystem is not technically dirty yet.
4561  */
4562 static int ext4_unfreeze(struct super_block *sb)
4563 {
4564 	if (sb->s_flags & MS_RDONLY)
4565 		return 0;
4566 
4567 	if (EXT4_SB(sb)->s_journal) {
4568 		/* Reset the needs_recovery flag before the fs is unlocked. */
4569 		ext4_set_feature_journal_needs_recovery(sb);
4570 	}
4571 
4572 	ext4_commit_super(sb, 1);
4573 	return 0;
4574 }
4575 
4576 /*
4577  * Structure to save mount options for ext4_remount's benefit
4578  */
4579 struct ext4_mount_options {
4580 	unsigned long s_mount_opt;
4581 	unsigned long s_mount_opt2;
4582 	kuid_t s_resuid;
4583 	kgid_t s_resgid;
4584 	unsigned long s_commit_interval;
4585 	u32 s_min_batch_time, s_max_batch_time;
4586 #ifdef CONFIG_QUOTA
4587 	int s_jquota_fmt;
4588 	char *s_qf_names[EXT4_MAXQUOTAS];
4589 #endif
4590 };
4591 
4592 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4593 {
4594 	struct ext4_super_block *es;
4595 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4596 	unsigned long old_sb_flags;
4597 	struct ext4_mount_options old_opts;
4598 	int enable_quota = 0;
4599 	ext4_group_t g;
4600 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4601 	int err = 0;
4602 #ifdef CONFIG_QUOTA
4603 	int i, j;
4604 #endif
4605 	char *orig_data = kstrdup(data, GFP_KERNEL);
4606 
4607 	/* Store the original options */
4608 	old_sb_flags = sb->s_flags;
4609 	old_opts.s_mount_opt = sbi->s_mount_opt;
4610 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4611 	old_opts.s_resuid = sbi->s_resuid;
4612 	old_opts.s_resgid = sbi->s_resgid;
4613 	old_opts.s_commit_interval = sbi->s_commit_interval;
4614 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4615 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4616 #ifdef CONFIG_QUOTA
4617 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4618 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4619 		if (sbi->s_qf_names[i]) {
4620 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4621 							 GFP_KERNEL);
4622 			if (!old_opts.s_qf_names[i]) {
4623 				for (j = 0; j < i; j++)
4624 					kfree(old_opts.s_qf_names[j]);
4625 				kfree(orig_data);
4626 				return -ENOMEM;
4627 			}
4628 		} else
4629 			old_opts.s_qf_names[i] = NULL;
4630 #endif
4631 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4632 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4633 
4634 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4635 		err = -EINVAL;
4636 		goto restore_opts;
4637 	}
4638 
4639 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4640 	    test_opt(sb, JOURNAL_CHECKSUM)) {
4641 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4642 			 "during remount not supported; ignoring");
4643 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4644 	}
4645 
4646 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4647 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4648 			ext4_msg(sb, KERN_ERR, "can't mount with "
4649 				 "both data=journal and delalloc");
4650 			err = -EINVAL;
4651 			goto restore_opts;
4652 		}
4653 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4654 			ext4_msg(sb, KERN_ERR, "can't mount with "
4655 				 "both data=journal and dioread_nolock");
4656 			err = -EINVAL;
4657 			goto restore_opts;
4658 		}
4659 		if (test_opt(sb, DAX)) {
4660 			ext4_msg(sb, KERN_ERR, "can't mount with "
4661 				 "both data=journal and dax");
4662 			err = -EINVAL;
4663 			goto restore_opts;
4664 		}
4665 	}
4666 
4667 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4668 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4669 			"dax flag with busy inodes while remounting");
4670 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4671 	}
4672 
4673 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4674 		ext4_abort(sb, "Abort forced by user");
4675 
4676 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4677 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4678 
4679 	es = sbi->s_es;
4680 
4681 	if (sbi->s_journal) {
4682 		ext4_init_journal_params(sb, sbi->s_journal);
4683 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4684 	}
4685 
4686 	if (*flags & MS_LAZYTIME)
4687 		sb->s_flags |= MS_LAZYTIME;
4688 
4689 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4690 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4691 			err = -EROFS;
4692 			goto restore_opts;
4693 		}
4694 
4695 		if (*flags & MS_RDONLY) {
4696 			err = sync_filesystem(sb);
4697 			if (err < 0)
4698 				goto restore_opts;
4699 			err = dquot_suspend(sb, -1);
4700 			if (err < 0)
4701 				goto restore_opts;
4702 
4703 			/*
4704 			 * First of all, the unconditional stuff we have to do
4705 			 * to disable replay of the journal when we next remount
4706 			 */
4707 			sb->s_flags |= MS_RDONLY;
4708 
4709 			/*
4710 			 * OK, test if we are remounting a valid rw partition
4711 			 * readonly, and if so set the rdonly flag and then
4712 			 * mark the partition as valid again.
4713 			 */
4714 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4715 			    (sbi->s_mount_state & EXT4_VALID_FS))
4716 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4717 
4718 			if (sbi->s_journal)
4719 				ext4_mark_recovery_complete(sb, es);
4720 		} else {
4721 			/* Make sure we can mount this feature set readwrite */
4722 			if (ext4_has_feature_readonly(sb) ||
4723 			    !ext4_feature_set_ok(sb, 0)) {
4724 				err = -EROFS;
4725 				goto restore_opts;
4726 			}
4727 			/*
4728 			 * Make sure the group descriptor checksums
4729 			 * are sane.  If they aren't, refuse to remount r/w.
4730 			 */
4731 			for (g = 0; g < sbi->s_groups_count; g++) {
4732 				struct ext4_group_desc *gdp =
4733 					ext4_get_group_desc(sb, g, NULL);
4734 
4735 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4736 					ext4_msg(sb, KERN_ERR,
4737 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4738 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
4739 					       le16_to_cpu(gdp->bg_checksum));
4740 					err = -EFSBADCRC;
4741 					goto restore_opts;
4742 				}
4743 			}
4744 
4745 			/*
4746 			 * If we have an unprocessed orphan list hanging
4747 			 * around from a previously readonly bdev mount,
4748 			 * require a full umount/remount for now.
4749 			 */
4750 			if (es->s_last_orphan) {
4751 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4752 				       "remount RDWR because of unprocessed "
4753 				       "orphan inode list.  Please "
4754 				       "umount/remount instead");
4755 				err = -EINVAL;
4756 				goto restore_opts;
4757 			}
4758 
4759 			/*
4760 			 * Mounting a RDONLY partition read-write, so reread
4761 			 * and store the current valid flag.  (It may have
4762 			 * been changed by e2fsck since we originally mounted
4763 			 * the partition.)
4764 			 */
4765 			if (sbi->s_journal)
4766 				ext4_clear_journal_err(sb, es);
4767 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4768 			if (!ext4_setup_super(sb, es, 0))
4769 				sb->s_flags &= ~MS_RDONLY;
4770 			if (ext4_has_feature_mmp(sb))
4771 				if (ext4_multi_mount_protect(sb,
4772 						le64_to_cpu(es->s_mmp_block))) {
4773 					err = -EROFS;
4774 					goto restore_opts;
4775 				}
4776 			enable_quota = 1;
4777 		}
4778 	}
4779 
4780 	/*
4781 	 * Reinitialize lazy itable initialization thread based on
4782 	 * current settings
4783 	 */
4784 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4785 		ext4_unregister_li_request(sb);
4786 	else {
4787 		ext4_group_t first_not_zeroed;
4788 		first_not_zeroed = ext4_has_uninit_itable(sb);
4789 		ext4_register_li_request(sb, first_not_zeroed);
4790 	}
4791 
4792 	ext4_setup_system_zone(sb);
4793 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4794 		ext4_commit_super(sb, 1);
4795 
4796 #ifdef CONFIG_QUOTA
4797 	/* Release old quota file names */
4798 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4799 		kfree(old_opts.s_qf_names[i]);
4800 	if (enable_quota) {
4801 		if (sb_any_quota_suspended(sb))
4802 			dquot_resume(sb, -1);
4803 		else if (ext4_has_feature_quota(sb)) {
4804 			err = ext4_enable_quotas(sb);
4805 			if (err)
4806 				goto restore_opts;
4807 		}
4808 	}
4809 #endif
4810 
4811 	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
4812 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4813 	kfree(orig_data);
4814 	return 0;
4815 
4816 restore_opts:
4817 	sb->s_flags = old_sb_flags;
4818 	sbi->s_mount_opt = old_opts.s_mount_opt;
4819 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4820 	sbi->s_resuid = old_opts.s_resuid;
4821 	sbi->s_resgid = old_opts.s_resgid;
4822 	sbi->s_commit_interval = old_opts.s_commit_interval;
4823 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4824 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4825 #ifdef CONFIG_QUOTA
4826 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4827 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
4828 		kfree(sbi->s_qf_names[i]);
4829 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4830 	}
4831 #endif
4832 	kfree(orig_data);
4833 	return err;
4834 }
4835 
4836 #ifdef CONFIG_QUOTA
4837 static int ext4_statfs_project(struct super_block *sb,
4838 			       kprojid_t projid, struct kstatfs *buf)
4839 {
4840 	struct kqid qid;
4841 	struct dquot *dquot;
4842 	u64 limit;
4843 	u64 curblock;
4844 
4845 	qid = make_kqid_projid(projid);
4846 	dquot = dqget(sb, qid);
4847 	if (IS_ERR(dquot))
4848 		return PTR_ERR(dquot);
4849 	spin_lock(&dq_data_lock);
4850 
4851 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
4852 		 dquot->dq_dqb.dqb_bsoftlimit :
4853 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
4854 	if (limit && buf->f_blocks > limit) {
4855 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
4856 		buf->f_blocks = limit;
4857 		buf->f_bfree = buf->f_bavail =
4858 			(buf->f_blocks > curblock) ?
4859 			 (buf->f_blocks - curblock) : 0;
4860 	}
4861 
4862 	limit = dquot->dq_dqb.dqb_isoftlimit ?
4863 		dquot->dq_dqb.dqb_isoftlimit :
4864 		dquot->dq_dqb.dqb_ihardlimit;
4865 	if (limit && buf->f_files > limit) {
4866 		buf->f_files = limit;
4867 		buf->f_ffree =
4868 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
4869 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
4870 	}
4871 
4872 	spin_unlock(&dq_data_lock);
4873 	dqput(dquot);
4874 	return 0;
4875 }
4876 #endif
4877 
4878 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4879 {
4880 	struct super_block *sb = dentry->d_sb;
4881 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4882 	struct ext4_super_block *es = sbi->s_es;
4883 	ext4_fsblk_t overhead = 0, resv_blocks;
4884 	u64 fsid;
4885 	s64 bfree;
4886 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4887 
4888 	if (!test_opt(sb, MINIX_DF))
4889 		overhead = sbi->s_overhead;
4890 
4891 	buf->f_type = EXT4_SUPER_MAGIC;
4892 	buf->f_bsize = sb->s_blocksize;
4893 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4894 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4895 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4896 	/* prevent underflow in case that few free space is available */
4897 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4898 	buf->f_bavail = buf->f_bfree -
4899 			(ext4_r_blocks_count(es) + resv_blocks);
4900 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4901 		buf->f_bavail = 0;
4902 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4903 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4904 	buf->f_namelen = EXT4_NAME_LEN;
4905 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4906 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4907 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4908 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4909 
4910 #ifdef CONFIG_QUOTA
4911 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
4912 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
4913 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
4914 #endif
4915 	return 0;
4916 }
4917 
4918 /* Helper function for writing quotas on sync - we need to start transaction
4919  * before quota file is locked for write. Otherwise the are possible deadlocks:
4920  * Process 1                         Process 2
4921  * ext4_create()                     quota_sync()
4922  *   jbd2_journal_start()                  write_dquot()
4923  *   dquot_initialize()                         down(dqio_mutex)
4924  *     down(dqio_mutex)                    jbd2_journal_start()
4925  *
4926  */
4927 
4928 #ifdef CONFIG_QUOTA
4929 
4930 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4931 {
4932 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4933 }
4934 
4935 static int ext4_write_dquot(struct dquot *dquot)
4936 {
4937 	int ret, err;
4938 	handle_t *handle;
4939 	struct inode *inode;
4940 
4941 	inode = dquot_to_inode(dquot);
4942 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4943 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4944 	if (IS_ERR(handle))
4945 		return PTR_ERR(handle);
4946 	ret = dquot_commit(dquot);
4947 	err = ext4_journal_stop(handle);
4948 	if (!ret)
4949 		ret = err;
4950 	return ret;
4951 }
4952 
4953 static int ext4_acquire_dquot(struct dquot *dquot)
4954 {
4955 	int ret, err;
4956 	handle_t *handle;
4957 
4958 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4959 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4960 	if (IS_ERR(handle))
4961 		return PTR_ERR(handle);
4962 	ret = dquot_acquire(dquot);
4963 	err = ext4_journal_stop(handle);
4964 	if (!ret)
4965 		ret = err;
4966 	return ret;
4967 }
4968 
4969 static int ext4_release_dquot(struct dquot *dquot)
4970 {
4971 	int ret, err;
4972 	handle_t *handle;
4973 
4974 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4975 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4976 	if (IS_ERR(handle)) {
4977 		/* Release dquot anyway to avoid endless cycle in dqput() */
4978 		dquot_release(dquot);
4979 		return PTR_ERR(handle);
4980 	}
4981 	ret = dquot_release(dquot);
4982 	err = ext4_journal_stop(handle);
4983 	if (!ret)
4984 		ret = err;
4985 	return ret;
4986 }
4987 
4988 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4989 {
4990 	struct super_block *sb = dquot->dq_sb;
4991 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4992 
4993 	/* Are we journaling quotas? */
4994 	if (ext4_has_feature_quota(sb) ||
4995 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
4996 		dquot_mark_dquot_dirty(dquot);
4997 		return ext4_write_dquot(dquot);
4998 	} else {
4999 		return dquot_mark_dquot_dirty(dquot);
5000 	}
5001 }
5002 
5003 static int ext4_write_info(struct super_block *sb, int type)
5004 {
5005 	int ret, err;
5006 	handle_t *handle;
5007 
5008 	/* Data block + inode block */
5009 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5010 	if (IS_ERR(handle))
5011 		return PTR_ERR(handle);
5012 	ret = dquot_commit_info(sb, type);
5013 	err = ext4_journal_stop(handle);
5014 	if (!ret)
5015 		ret = err;
5016 	return ret;
5017 }
5018 
5019 /*
5020  * Turn on quotas during mount time - we need to find
5021  * the quota file and such...
5022  */
5023 static int ext4_quota_on_mount(struct super_block *sb, int type)
5024 {
5025 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5026 					EXT4_SB(sb)->s_jquota_fmt, type);
5027 }
5028 
5029 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5030 {
5031 	struct ext4_inode_info *ei = EXT4_I(inode);
5032 
5033 	/* The first argument of lockdep_set_subclass has to be
5034 	 * *exactly* the same as the argument to init_rwsem() --- in
5035 	 * this case, in init_once() --- or lockdep gets unhappy
5036 	 * because the name of the lock is set using the
5037 	 * stringification of the argument to init_rwsem().
5038 	 */
5039 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5040 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5041 }
5042 
5043 /*
5044  * Standard function to be called on quota_on
5045  */
5046 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5047 			 struct path *path)
5048 {
5049 	int err;
5050 
5051 	if (!test_opt(sb, QUOTA))
5052 		return -EINVAL;
5053 
5054 	/* Quotafile not on the same filesystem? */
5055 	if (path->dentry->d_sb != sb)
5056 		return -EXDEV;
5057 	/* Journaling quota? */
5058 	if (EXT4_SB(sb)->s_qf_names[type]) {
5059 		/* Quotafile not in fs root? */
5060 		if (path->dentry->d_parent != sb->s_root)
5061 			ext4_msg(sb, KERN_WARNING,
5062 				"Quota file not on filesystem root. "
5063 				"Journaled quota will not work");
5064 	}
5065 
5066 	/*
5067 	 * When we journal data on quota file, we have to flush journal to see
5068 	 * all updates to the file when we bypass pagecache...
5069 	 */
5070 	if (EXT4_SB(sb)->s_journal &&
5071 	    ext4_should_journal_data(d_inode(path->dentry))) {
5072 		/*
5073 		 * We don't need to lock updates but journal_flush() could
5074 		 * otherwise be livelocked...
5075 		 */
5076 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5077 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5078 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5079 		if (err)
5080 			return err;
5081 	}
5082 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5083 	err = dquot_quota_on(sb, type, format_id, path);
5084 	if (err)
5085 		lockdep_set_quota_inode(path->dentry->d_inode,
5086 					     I_DATA_SEM_NORMAL);
5087 	return err;
5088 }
5089 
5090 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5091 			     unsigned int flags)
5092 {
5093 	int err;
5094 	struct inode *qf_inode;
5095 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5096 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5097 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5098 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5099 	};
5100 
5101 	BUG_ON(!ext4_has_feature_quota(sb));
5102 
5103 	if (!qf_inums[type])
5104 		return -EPERM;
5105 
5106 	qf_inode = ext4_iget(sb, qf_inums[type]);
5107 	if (IS_ERR(qf_inode)) {
5108 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5109 		return PTR_ERR(qf_inode);
5110 	}
5111 
5112 	/* Don't account quota for quota files to avoid recursion */
5113 	qf_inode->i_flags |= S_NOQUOTA;
5114 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5115 	err = dquot_enable(qf_inode, type, format_id, flags);
5116 	iput(qf_inode);
5117 	if (err)
5118 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5119 
5120 	return err;
5121 }
5122 
5123 /* Enable usage tracking for all quota types. */
5124 static int ext4_enable_quotas(struct super_block *sb)
5125 {
5126 	int type, err = 0;
5127 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5128 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5129 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5130 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5131 	};
5132 
5133 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5134 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5135 		if (qf_inums[type]) {
5136 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5137 						DQUOT_USAGE_ENABLED);
5138 			if (err) {
5139 				ext4_warning(sb,
5140 					"Failed to enable quota tracking "
5141 					"(type=%d, err=%d). Please run "
5142 					"e2fsck to fix.", type, err);
5143 				return err;
5144 			}
5145 		}
5146 	}
5147 	return 0;
5148 }
5149 
5150 static int ext4_quota_off(struct super_block *sb, int type)
5151 {
5152 	struct inode *inode = sb_dqopt(sb)->files[type];
5153 	handle_t *handle;
5154 
5155 	/* Force all delayed allocation blocks to be allocated.
5156 	 * Caller already holds s_umount sem */
5157 	if (test_opt(sb, DELALLOC))
5158 		sync_filesystem(sb);
5159 
5160 	if (!inode)
5161 		goto out;
5162 
5163 	/* Update modification times of quota files when userspace can
5164 	 * start looking at them */
5165 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5166 	if (IS_ERR(handle))
5167 		goto out;
5168 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5169 	ext4_mark_inode_dirty(handle, inode);
5170 	ext4_journal_stop(handle);
5171 
5172 out:
5173 	return dquot_quota_off(sb, type);
5174 }
5175 
5176 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5177  * acquiring the locks... As quota files are never truncated and quota code
5178  * itself serializes the operations (and no one else should touch the files)
5179  * we don't have to be afraid of races */
5180 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5181 			       size_t len, loff_t off)
5182 {
5183 	struct inode *inode = sb_dqopt(sb)->files[type];
5184 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5185 	int offset = off & (sb->s_blocksize - 1);
5186 	int tocopy;
5187 	size_t toread;
5188 	struct buffer_head *bh;
5189 	loff_t i_size = i_size_read(inode);
5190 
5191 	if (off > i_size)
5192 		return 0;
5193 	if (off+len > i_size)
5194 		len = i_size-off;
5195 	toread = len;
5196 	while (toread > 0) {
5197 		tocopy = sb->s_blocksize - offset < toread ?
5198 				sb->s_blocksize - offset : toread;
5199 		bh = ext4_bread(NULL, inode, blk, 0);
5200 		if (IS_ERR(bh))
5201 			return PTR_ERR(bh);
5202 		if (!bh)	/* A hole? */
5203 			memset(data, 0, tocopy);
5204 		else
5205 			memcpy(data, bh->b_data+offset, tocopy);
5206 		brelse(bh);
5207 		offset = 0;
5208 		toread -= tocopy;
5209 		data += tocopy;
5210 		blk++;
5211 	}
5212 	return len;
5213 }
5214 
5215 /* Write to quotafile (we know the transaction is already started and has
5216  * enough credits) */
5217 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5218 				const char *data, size_t len, loff_t off)
5219 {
5220 	struct inode *inode = sb_dqopt(sb)->files[type];
5221 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5222 	int err, offset = off & (sb->s_blocksize - 1);
5223 	int retries = 0;
5224 	struct buffer_head *bh;
5225 	handle_t *handle = journal_current_handle();
5226 
5227 	if (EXT4_SB(sb)->s_journal && !handle) {
5228 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5229 			" cancelled because transaction is not started",
5230 			(unsigned long long)off, (unsigned long long)len);
5231 		return -EIO;
5232 	}
5233 	/*
5234 	 * Since we account only one data block in transaction credits,
5235 	 * then it is impossible to cross a block boundary.
5236 	 */
5237 	if (sb->s_blocksize - offset < len) {
5238 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5239 			" cancelled because not block aligned",
5240 			(unsigned long long)off, (unsigned long long)len);
5241 		return -EIO;
5242 	}
5243 
5244 	do {
5245 		bh = ext4_bread(handle, inode, blk,
5246 				EXT4_GET_BLOCKS_CREATE |
5247 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5248 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5249 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5250 	if (IS_ERR(bh))
5251 		return PTR_ERR(bh);
5252 	if (!bh)
5253 		goto out;
5254 	BUFFER_TRACE(bh, "get write access");
5255 	err = ext4_journal_get_write_access(handle, bh);
5256 	if (err) {
5257 		brelse(bh);
5258 		return err;
5259 	}
5260 	lock_buffer(bh);
5261 	memcpy(bh->b_data+offset, data, len);
5262 	flush_dcache_page(bh->b_page);
5263 	unlock_buffer(bh);
5264 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5265 	brelse(bh);
5266 out:
5267 	if (inode->i_size < off + len) {
5268 		i_size_write(inode, off + len);
5269 		EXT4_I(inode)->i_disksize = inode->i_size;
5270 		ext4_mark_inode_dirty(handle, inode);
5271 	}
5272 	return len;
5273 }
5274 
5275 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5276 {
5277 	const struct quota_format_ops	*ops;
5278 
5279 	if (!sb_has_quota_loaded(sb, qid->type))
5280 		return -ESRCH;
5281 	ops = sb_dqopt(sb)->ops[qid->type];
5282 	if (!ops || !ops->get_next_id)
5283 		return -ENOSYS;
5284 	return dquot_get_next_id(sb, qid);
5285 }
5286 #endif
5287 
5288 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5289 		       const char *dev_name, void *data)
5290 {
5291 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5292 }
5293 
5294 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5295 static inline void register_as_ext2(void)
5296 {
5297 	int err = register_filesystem(&ext2_fs_type);
5298 	if (err)
5299 		printk(KERN_WARNING
5300 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5301 }
5302 
5303 static inline void unregister_as_ext2(void)
5304 {
5305 	unregister_filesystem(&ext2_fs_type);
5306 }
5307 
5308 static inline int ext2_feature_set_ok(struct super_block *sb)
5309 {
5310 	if (ext4_has_unknown_ext2_incompat_features(sb))
5311 		return 0;
5312 	if (sb->s_flags & MS_RDONLY)
5313 		return 1;
5314 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5315 		return 0;
5316 	return 1;
5317 }
5318 #else
5319 static inline void register_as_ext2(void) { }
5320 static inline void unregister_as_ext2(void) { }
5321 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5322 #endif
5323 
5324 static inline void register_as_ext3(void)
5325 {
5326 	int err = register_filesystem(&ext3_fs_type);
5327 	if (err)
5328 		printk(KERN_WARNING
5329 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5330 }
5331 
5332 static inline void unregister_as_ext3(void)
5333 {
5334 	unregister_filesystem(&ext3_fs_type);
5335 }
5336 
5337 static inline int ext3_feature_set_ok(struct super_block *sb)
5338 {
5339 	if (ext4_has_unknown_ext3_incompat_features(sb))
5340 		return 0;
5341 	if (!ext4_has_feature_journal(sb))
5342 		return 0;
5343 	if (sb->s_flags & MS_RDONLY)
5344 		return 1;
5345 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5346 		return 0;
5347 	return 1;
5348 }
5349 
5350 static struct file_system_type ext4_fs_type = {
5351 	.owner		= THIS_MODULE,
5352 	.name		= "ext4",
5353 	.mount		= ext4_mount,
5354 	.kill_sb	= kill_block_super,
5355 	.fs_flags	= FS_REQUIRES_DEV,
5356 };
5357 MODULE_ALIAS_FS("ext4");
5358 
5359 /* Shared across all ext4 file systems */
5360 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5361 
5362 static int __init ext4_init_fs(void)
5363 {
5364 	int i, err;
5365 
5366 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5367 	ext4_li_info = NULL;
5368 	mutex_init(&ext4_li_mtx);
5369 
5370 	/* Build-time check for flags consistency */
5371 	ext4_check_flag_values();
5372 
5373 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5374 		init_waitqueue_head(&ext4__ioend_wq[i]);
5375 
5376 	err = ext4_init_es();
5377 	if (err)
5378 		return err;
5379 
5380 	err = ext4_init_pageio();
5381 	if (err)
5382 		goto out5;
5383 
5384 	err = ext4_init_system_zone();
5385 	if (err)
5386 		goto out4;
5387 
5388 	err = ext4_init_sysfs();
5389 	if (err)
5390 		goto out3;
5391 
5392 	err = ext4_init_mballoc();
5393 	if (err)
5394 		goto out2;
5395 	err = init_inodecache();
5396 	if (err)
5397 		goto out1;
5398 	register_as_ext3();
5399 	register_as_ext2();
5400 	err = register_filesystem(&ext4_fs_type);
5401 	if (err)
5402 		goto out;
5403 
5404 	return 0;
5405 out:
5406 	unregister_as_ext2();
5407 	unregister_as_ext3();
5408 	destroy_inodecache();
5409 out1:
5410 	ext4_exit_mballoc();
5411 out2:
5412 	ext4_exit_sysfs();
5413 out3:
5414 	ext4_exit_system_zone();
5415 out4:
5416 	ext4_exit_pageio();
5417 out5:
5418 	ext4_exit_es();
5419 
5420 	return err;
5421 }
5422 
5423 static void __exit ext4_exit_fs(void)
5424 {
5425 	ext4_exit_crypto();
5426 	ext4_destroy_lazyinit_thread();
5427 	unregister_as_ext2();
5428 	unregister_as_ext3();
5429 	unregister_filesystem(&ext4_fs_type);
5430 	destroy_inodecache();
5431 	ext4_exit_mballoc();
5432 	ext4_exit_sysfs();
5433 	ext4_exit_system_zone();
5434 	ext4_exit_pageio();
5435 	ext4_exit_es();
5436 }
5437 
5438 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5439 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5440 MODULE_LICENSE("GPL");
5441 module_init(ext4_init_fs)
5442 module_exit(ext4_exit_fs)
5443