xref: /linux/fs/ext4/super.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
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/jbd2.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.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/proc_fs.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/cleancache.h>
42 #include <asm/uaccess.h>
43 
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46 
47 #include "ext4.h"
48 #include "ext4_extents.h"	/* Needed for trace points definition */
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/ext4.h>
56 
57 static struct proc_dir_entry *ext4_proc_root;
58 static struct kset *ext4_kset;
59 static struct ext4_lazy_init *ext4_li_info;
60 static struct mutex ext4_li_mtx;
61 static struct ext4_features *ext4_feat;
62 static int ext4_mballoc_ready;
63 
64 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
65 			     unsigned long journal_devnum);
66 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
67 static int ext4_commit_super(struct super_block *sb, int sync);
68 static void ext4_mark_recovery_complete(struct super_block *sb,
69 					struct ext4_super_block *es);
70 static void ext4_clear_journal_err(struct super_block *sb,
71 				   struct ext4_super_block *es);
72 static int ext4_sync_fs(struct super_block *sb, int wait);
73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
75 static int ext4_unfreeze(struct super_block *sb);
76 static int ext4_freeze(struct super_block *sb);
77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
78 		       const char *dev_name, void *data);
79 static inline int ext2_feature_set_ok(struct super_block *sb);
80 static inline int ext3_feature_set_ok(struct super_block *sb);
81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
86 
87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
88 static struct file_system_type ext2_fs_type = {
89 	.owner		= THIS_MODULE,
90 	.name		= "ext2",
91 	.mount		= ext4_mount,
92 	.kill_sb	= kill_block_super,
93 	.fs_flags	= FS_REQUIRES_DEV,
94 };
95 MODULE_ALIAS_FS("ext2");
96 MODULE_ALIAS("ext2");
97 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
98 #else
99 #define IS_EXT2_SB(sb) (0)
100 #endif
101 
102 
103 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
104 static struct file_system_type ext3_fs_type = {
105 	.owner		= THIS_MODULE,
106 	.name		= "ext3",
107 	.mount		= ext4_mount,
108 	.kill_sb	= kill_block_super,
109 	.fs_flags	= FS_REQUIRES_DEV,
110 };
111 MODULE_ALIAS_FS("ext3");
112 MODULE_ALIAS("ext3");
113 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
114 #else
115 #define IS_EXT3_SB(sb) (0)
116 #endif
117 
118 static int ext4_verify_csum_type(struct super_block *sb,
119 				 struct ext4_super_block *es)
120 {
121 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
122 					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
123 		return 1;
124 
125 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
126 }
127 
128 static __le32 ext4_superblock_csum(struct super_block *sb,
129 				   struct ext4_super_block *es)
130 {
131 	struct ext4_sb_info *sbi = EXT4_SB(sb);
132 	int offset = offsetof(struct ext4_super_block, s_checksum);
133 	__u32 csum;
134 
135 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
136 
137 	return cpu_to_le32(csum);
138 }
139 
140 static int ext4_superblock_csum_verify(struct super_block *sb,
141 				       struct ext4_super_block *es)
142 {
143 	if (!ext4_has_metadata_csum(sb))
144 		return 1;
145 
146 	return es->s_checksum == ext4_superblock_csum(sb, es);
147 }
148 
149 void ext4_superblock_csum_set(struct super_block *sb)
150 {
151 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
152 
153 	if (!ext4_has_metadata_csum(sb))
154 		return;
155 
156 	es->s_checksum = ext4_superblock_csum(sb, es);
157 }
158 
159 void *ext4_kvmalloc(size_t size, gfp_t flags)
160 {
161 	void *ret;
162 
163 	ret = kmalloc(size, flags | __GFP_NOWARN);
164 	if (!ret)
165 		ret = __vmalloc(size, flags, PAGE_KERNEL);
166 	return ret;
167 }
168 
169 void *ext4_kvzalloc(size_t size, gfp_t flags)
170 {
171 	void *ret;
172 
173 	ret = kzalloc(size, flags | __GFP_NOWARN);
174 	if (!ret)
175 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
176 	return ret;
177 }
178 
179 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
180 			       struct ext4_group_desc *bg)
181 {
182 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
183 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
184 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
185 }
186 
187 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
188 			       struct ext4_group_desc *bg)
189 {
190 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
191 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
192 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
193 }
194 
195 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
196 			      struct ext4_group_desc *bg)
197 {
198 	return le32_to_cpu(bg->bg_inode_table_lo) |
199 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
200 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
201 }
202 
203 __u32 ext4_free_group_clusters(struct super_block *sb,
204 			       struct ext4_group_desc *bg)
205 {
206 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
207 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
208 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
209 }
210 
211 __u32 ext4_free_inodes_count(struct super_block *sb,
212 			      struct ext4_group_desc *bg)
213 {
214 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
215 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
216 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
217 }
218 
219 __u32 ext4_used_dirs_count(struct super_block *sb,
220 			      struct ext4_group_desc *bg)
221 {
222 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
223 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
224 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
225 }
226 
227 __u32 ext4_itable_unused_count(struct super_block *sb,
228 			      struct ext4_group_desc *bg)
229 {
230 	return le16_to_cpu(bg->bg_itable_unused_lo) |
231 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
232 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
233 }
234 
235 void ext4_block_bitmap_set(struct super_block *sb,
236 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
237 {
238 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
239 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
240 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
241 }
242 
243 void ext4_inode_bitmap_set(struct super_block *sb,
244 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
245 {
246 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
247 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
248 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
249 }
250 
251 void ext4_inode_table_set(struct super_block *sb,
252 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
253 {
254 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
255 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
256 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
257 }
258 
259 void ext4_free_group_clusters_set(struct super_block *sb,
260 				  struct ext4_group_desc *bg, __u32 count)
261 {
262 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
263 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
264 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
265 }
266 
267 void ext4_free_inodes_set(struct super_block *sb,
268 			  struct ext4_group_desc *bg, __u32 count)
269 {
270 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
271 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
272 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
273 }
274 
275 void ext4_used_dirs_set(struct super_block *sb,
276 			  struct ext4_group_desc *bg, __u32 count)
277 {
278 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
279 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
280 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
281 }
282 
283 void ext4_itable_unused_set(struct super_block *sb,
284 			  struct ext4_group_desc *bg, __u32 count)
285 {
286 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
287 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
288 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
289 }
290 
291 
292 static void __save_error_info(struct super_block *sb, const char *func,
293 			    unsigned int line)
294 {
295 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
296 
297 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
298 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
299 	es->s_last_error_time = cpu_to_le32(get_seconds());
300 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
301 	es->s_last_error_line = cpu_to_le32(line);
302 	if (!es->s_first_error_time) {
303 		es->s_first_error_time = es->s_last_error_time;
304 		strncpy(es->s_first_error_func, func,
305 			sizeof(es->s_first_error_func));
306 		es->s_first_error_line = cpu_to_le32(line);
307 		es->s_first_error_ino = es->s_last_error_ino;
308 		es->s_first_error_block = es->s_last_error_block;
309 	}
310 	/*
311 	 * Start the daily error reporting function if it hasn't been
312 	 * started already
313 	 */
314 	if (!es->s_error_count)
315 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
316 	le32_add_cpu(&es->s_error_count, 1);
317 }
318 
319 static void save_error_info(struct super_block *sb, const char *func,
320 			    unsigned int line)
321 {
322 	__save_error_info(sb, func, line);
323 	ext4_commit_super(sb, 1);
324 }
325 
326 /*
327  * The del_gendisk() function uninitializes the disk-specific data
328  * structures, including the bdi structure, without telling anyone
329  * else.  Once this happens, any attempt to call mark_buffer_dirty()
330  * (for example, by ext4_commit_super), will cause a kernel OOPS.
331  * This is a kludge to prevent these oops until we can put in a proper
332  * hook in del_gendisk() to inform the VFS and file system layers.
333  */
334 static int block_device_ejected(struct super_block *sb)
335 {
336 	struct inode *bd_inode = sb->s_bdev->bd_inode;
337 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
338 
339 	return bdi->dev == NULL;
340 }
341 
342 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
343 {
344 	struct super_block		*sb = journal->j_private;
345 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
346 	int				error = is_journal_aborted(journal);
347 	struct ext4_journal_cb_entry	*jce;
348 
349 	BUG_ON(txn->t_state == T_FINISHED);
350 	spin_lock(&sbi->s_md_lock);
351 	while (!list_empty(&txn->t_private_list)) {
352 		jce = list_entry(txn->t_private_list.next,
353 				 struct ext4_journal_cb_entry, jce_list);
354 		list_del_init(&jce->jce_list);
355 		spin_unlock(&sbi->s_md_lock);
356 		jce->jce_func(sb, jce, error);
357 		spin_lock(&sbi->s_md_lock);
358 	}
359 	spin_unlock(&sbi->s_md_lock);
360 }
361 
362 /* Deal with the reporting of failure conditions on a filesystem such as
363  * inconsistencies detected or read IO failures.
364  *
365  * On ext2, we can store the error state of the filesystem in the
366  * superblock.  That is not possible on ext4, because we may have other
367  * write ordering constraints on the superblock which prevent us from
368  * writing it out straight away; and given that the journal is about to
369  * be aborted, we can't rely on the current, or future, transactions to
370  * write out the superblock safely.
371  *
372  * We'll just use the jbd2_journal_abort() error code to record an error in
373  * the journal instead.  On recovery, the journal will complain about
374  * that error until we've noted it down and cleared it.
375  */
376 
377 static void ext4_handle_error(struct super_block *sb)
378 {
379 	if (sb->s_flags & MS_RDONLY)
380 		return;
381 
382 	if (!test_opt(sb, ERRORS_CONT)) {
383 		journal_t *journal = EXT4_SB(sb)->s_journal;
384 
385 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
386 		if (journal)
387 			jbd2_journal_abort(journal, -EIO);
388 	}
389 	if (test_opt(sb, ERRORS_RO)) {
390 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
391 		/*
392 		 * Make sure updated value of ->s_mount_flags will be visible
393 		 * before ->s_flags update
394 		 */
395 		smp_wmb();
396 		sb->s_flags |= MS_RDONLY;
397 	}
398 	if (test_opt(sb, ERRORS_PANIC))
399 		panic("EXT4-fs (device %s): panic forced after error\n",
400 			sb->s_id);
401 }
402 
403 #define ext4_error_ratelimit(sb)					\
404 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
405 			     "EXT4-fs error")
406 
407 void __ext4_error(struct super_block *sb, const char *function,
408 		  unsigned int line, const char *fmt, ...)
409 {
410 	struct va_format vaf;
411 	va_list args;
412 
413 	if (ext4_error_ratelimit(sb)) {
414 		va_start(args, fmt);
415 		vaf.fmt = fmt;
416 		vaf.va = &args;
417 		printk(KERN_CRIT
418 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
419 		       sb->s_id, function, line, current->comm, &vaf);
420 		va_end(args);
421 	}
422 	save_error_info(sb, function, line);
423 	ext4_handle_error(sb);
424 }
425 
426 void __ext4_error_inode(struct inode *inode, const char *function,
427 			unsigned int line, ext4_fsblk_t block,
428 			const char *fmt, ...)
429 {
430 	va_list args;
431 	struct va_format vaf;
432 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
433 
434 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
435 	es->s_last_error_block = cpu_to_le64(block);
436 	if (ext4_error_ratelimit(inode->i_sb)) {
437 		va_start(args, fmt);
438 		vaf.fmt = fmt;
439 		vaf.va = &args;
440 		if (block)
441 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
442 			       "inode #%lu: block %llu: comm %s: %pV\n",
443 			       inode->i_sb->s_id, function, line, inode->i_ino,
444 			       block, current->comm, &vaf);
445 		else
446 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
447 			       "inode #%lu: comm %s: %pV\n",
448 			       inode->i_sb->s_id, function, line, inode->i_ino,
449 			       current->comm, &vaf);
450 		va_end(args);
451 	}
452 	save_error_info(inode->i_sb, function, line);
453 	ext4_handle_error(inode->i_sb);
454 }
455 
456 void __ext4_error_file(struct file *file, const char *function,
457 		       unsigned int line, ext4_fsblk_t block,
458 		       const char *fmt, ...)
459 {
460 	va_list args;
461 	struct va_format vaf;
462 	struct ext4_super_block *es;
463 	struct inode *inode = file_inode(file);
464 	char pathname[80], *path;
465 
466 	es = EXT4_SB(inode->i_sb)->s_es;
467 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
468 	if (ext4_error_ratelimit(inode->i_sb)) {
469 		path = d_path(&(file->f_path), pathname, sizeof(pathname));
470 		if (IS_ERR(path))
471 			path = "(unknown)";
472 		va_start(args, fmt);
473 		vaf.fmt = fmt;
474 		vaf.va = &args;
475 		if (block)
476 			printk(KERN_CRIT
477 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
478 			       "block %llu: comm %s: path %s: %pV\n",
479 			       inode->i_sb->s_id, function, line, inode->i_ino,
480 			       block, current->comm, path, &vaf);
481 		else
482 			printk(KERN_CRIT
483 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
484 			       "comm %s: path %s: %pV\n",
485 			       inode->i_sb->s_id, function, line, inode->i_ino,
486 			       current->comm, path, &vaf);
487 		va_end(args);
488 	}
489 	save_error_info(inode->i_sb, function, line);
490 	ext4_handle_error(inode->i_sb);
491 }
492 
493 const char *ext4_decode_error(struct super_block *sb, int errno,
494 			      char nbuf[16])
495 {
496 	char *errstr = NULL;
497 
498 	switch (errno) {
499 	case -EIO:
500 		errstr = "IO failure";
501 		break;
502 	case -ENOMEM:
503 		errstr = "Out of memory";
504 		break;
505 	case -EROFS:
506 		if (!sb || (EXT4_SB(sb)->s_journal &&
507 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
508 			errstr = "Journal has aborted";
509 		else
510 			errstr = "Readonly filesystem";
511 		break;
512 	default:
513 		/* If the caller passed in an extra buffer for unknown
514 		 * errors, textualise them now.  Else we just return
515 		 * NULL. */
516 		if (nbuf) {
517 			/* Check for truncated error codes... */
518 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
519 				errstr = nbuf;
520 		}
521 		break;
522 	}
523 
524 	return errstr;
525 }
526 
527 /* __ext4_std_error decodes expected errors from journaling functions
528  * automatically and invokes the appropriate error response.  */
529 
530 void __ext4_std_error(struct super_block *sb, const char *function,
531 		      unsigned int line, int errno)
532 {
533 	char nbuf[16];
534 	const char *errstr;
535 
536 	/* Special case: if the error is EROFS, and we're not already
537 	 * inside a transaction, then there's really no point in logging
538 	 * an error. */
539 	if (errno == -EROFS && journal_current_handle() == NULL &&
540 	    (sb->s_flags & MS_RDONLY))
541 		return;
542 
543 	if (ext4_error_ratelimit(sb)) {
544 		errstr = ext4_decode_error(sb, errno, nbuf);
545 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
546 		       sb->s_id, function, line, errstr);
547 	}
548 
549 	save_error_info(sb, function, line);
550 	ext4_handle_error(sb);
551 }
552 
553 /*
554  * ext4_abort is a much stronger failure handler than ext4_error.  The
555  * abort function may be used to deal with unrecoverable failures such
556  * as journal IO errors or ENOMEM at a critical moment in log management.
557  *
558  * We unconditionally force the filesystem into an ABORT|READONLY state,
559  * unless the error response on the fs has been set to panic in which
560  * case we take the easy way out and panic immediately.
561  */
562 
563 void __ext4_abort(struct super_block *sb, const char *function,
564 		unsigned int line, const char *fmt, ...)
565 {
566 	va_list args;
567 
568 	save_error_info(sb, function, line);
569 	va_start(args, fmt);
570 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
571 	       function, line);
572 	vprintk(fmt, args);
573 	printk("\n");
574 	va_end(args);
575 
576 	if ((sb->s_flags & MS_RDONLY) == 0) {
577 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
578 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
579 		/*
580 		 * Make sure updated value of ->s_mount_flags will be visible
581 		 * before ->s_flags update
582 		 */
583 		smp_wmb();
584 		sb->s_flags |= MS_RDONLY;
585 		if (EXT4_SB(sb)->s_journal)
586 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
587 		save_error_info(sb, function, line);
588 	}
589 	if (test_opt(sb, ERRORS_PANIC))
590 		panic("EXT4-fs panic from previous error\n");
591 }
592 
593 void __ext4_msg(struct super_block *sb,
594 		const char *prefix, const char *fmt, ...)
595 {
596 	struct va_format vaf;
597 	va_list args;
598 
599 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
600 		return;
601 
602 	va_start(args, fmt);
603 	vaf.fmt = fmt;
604 	vaf.va = &args;
605 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
606 	va_end(args);
607 }
608 
609 void __ext4_warning(struct super_block *sb, const char *function,
610 		    unsigned int line, const char *fmt, ...)
611 {
612 	struct va_format vaf;
613 	va_list args;
614 
615 	if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
616 			  "EXT4-fs warning"))
617 		return;
618 
619 	va_start(args, fmt);
620 	vaf.fmt = fmt;
621 	vaf.va = &args;
622 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
623 	       sb->s_id, function, line, &vaf);
624 	va_end(args);
625 }
626 
627 void __ext4_grp_locked_error(const char *function, unsigned int line,
628 			     struct super_block *sb, ext4_group_t grp,
629 			     unsigned long ino, ext4_fsblk_t block,
630 			     const char *fmt, ...)
631 __releases(bitlock)
632 __acquires(bitlock)
633 {
634 	struct va_format vaf;
635 	va_list args;
636 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
637 
638 	es->s_last_error_ino = cpu_to_le32(ino);
639 	es->s_last_error_block = cpu_to_le64(block);
640 	__save_error_info(sb, function, line);
641 
642 	if (ext4_error_ratelimit(sb)) {
643 		va_start(args, fmt);
644 		vaf.fmt = fmt;
645 		vaf.va = &args;
646 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
647 		       sb->s_id, function, line, grp);
648 		if (ino)
649 			printk(KERN_CONT "inode %lu: ", ino);
650 		if (block)
651 			printk(KERN_CONT "block %llu:",
652 			       (unsigned long long) block);
653 		printk(KERN_CONT "%pV\n", &vaf);
654 		va_end(args);
655 	}
656 
657 	if (test_opt(sb, ERRORS_CONT)) {
658 		ext4_commit_super(sb, 0);
659 		return;
660 	}
661 
662 	ext4_unlock_group(sb, grp);
663 	ext4_handle_error(sb);
664 	/*
665 	 * We only get here in the ERRORS_RO case; relocking the group
666 	 * may be dangerous, but nothing bad will happen since the
667 	 * filesystem will have already been marked read/only and the
668 	 * journal has been aborted.  We return 1 as a hint to callers
669 	 * who might what to use the return value from
670 	 * ext4_grp_locked_error() to distinguish between the
671 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
672 	 * aggressively from the ext4 function in question, with a
673 	 * more appropriate error code.
674 	 */
675 	ext4_lock_group(sb, grp);
676 	return;
677 }
678 
679 void ext4_update_dynamic_rev(struct super_block *sb)
680 {
681 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
682 
683 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
684 		return;
685 
686 	ext4_warning(sb,
687 		     "updating to rev %d because of new feature flag, "
688 		     "running e2fsck is recommended",
689 		     EXT4_DYNAMIC_REV);
690 
691 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
692 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
693 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
694 	/* leave es->s_feature_*compat flags alone */
695 	/* es->s_uuid will be set by e2fsck if empty */
696 
697 	/*
698 	 * The rest of the superblock fields should be zero, and if not it
699 	 * means they are likely already in use, so leave them alone.  We
700 	 * can leave it up to e2fsck to clean up any inconsistencies there.
701 	 */
702 }
703 
704 /*
705  * Open the external journal device
706  */
707 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
708 {
709 	struct block_device *bdev;
710 	char b[BDEVNAME_SIZE];
711 
712 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
713 	if (IS_ERR(bdev))
714 		goto fail;
715 	return bdev;
716 
717 fail:
718 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
719 			__bdevname(dev, b), PTR_ERR(bdev));
720 	return NULL;
721 }
722 
723 /*
724  * Release the journal device
725  */
726 static void ext4_blkdev_put(struct block_device *bdev)
727 {
728 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
729 }
730 
731 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
732 {
733 	struct block_device *bdev;
734 	bdev = sbi->journal_bdev;
735 	if (bdev) {
736 		ext4_blkdev_put(bdev);
737 		sbi->journal_bdev = NULL;
738 	}
739 }
740 
741 static inline struct inode *orphan_list_entry(struct list_head *l)
742 {
743 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
744 }
745 
746 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
747 {
748 	struct list_head *l;
749 
750 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
751 		 le32_to_cpu(sbi->s_es->s_last_orphan));
752 
753 	printk(KERN_ERR "sb_info orphan list:\n");
754 	list_for_each(l, &sbi->s_orphan) {
755 		struct inode *inode = orphan_list_entry(l);
756 		printk(KERN_ERR "  "
757 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
758 		       inode->i_sb->s_id, inode->i_ino, inode,
759 		       inode->i_mode, inode->i_nlink,
760 		       NEXT_ORPHAN(inode));
761 	}
762 }
763 
764 static void ext4_put_super(struct super_block *sb)
765 {
766 	struct ext4_sb_info *sbi = EXT4_SB(sb);
767 	struct ext4_super_block *es = sbi->s_es;
768 	int i, err;
769 
770 	ext4_unregister_li_request(sb);
771 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
772 
773 	flush_workqueue(sbi->rsv_conversion_wq);
774 	destroy_workqueue(sbi->rsv_conversion_wq);
775 
776 	if (sbi->s_journal) {
777 		err = jbd2_journal_destroy(sbi->s_journal);
778 		sbi->s_journal = NULL;
779 		if (err < 0)
780 			ext4_abort(sb, "Couldn't clean up the journal");
781 	}
782 
783 	ext4_es_unregister_shrinker(sbi);
784 	del_timer_sync(&sbi->s_err_report);
785 	ext4_release_system_zone(sb);
786 	ext4_mb_release(sb);
787 	ext4_ext_release(sb);
788 	ext4_xattr_put_super(sb);
789 
790 	if (!(sb->s_flags & MS_RDONLY)) {
791 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
792 		es->s_state = cpu_to_le16(sbi->s_mount_state);
793 	}
794 	if (!(sb->s_flags & MS_RDONLY))
795 		ext4_commit_super(sb, 1);
796 
797 	if (sbi->s_proc) {
798 		remove_proc_entry("options", sbi->s_proc);
799 		remove_proc_entry(sb->s_id, ext4_proc_root);
800 	}
801 	kobject_del(&sbi->s_kobj);
802 
803 	for (i = 0; i < sbi->s_gdb_count; i++)
804 		brelse(sbi->s_group_desc[i]);
805 	kvfree(sbi->s_group_desc);
806 	kvfree(sbi->s_flex_groups);
807 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
808 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
809 	percpu_counter_destroy(&sbi->s_dirs_counter);
810 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
811 	brelse(sbi->s_sbh);
812 #ifdef CONFIG_QUOTA
813 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
814 		kfree(sbi->s_qf_names[i]);
815 #endif
816 
817 	/* Debugging code just in case the in-memory inode orphan list
818 	 * isn't empty.  The on-disk one can be non-empty if we've
819 	 * detected an error and taken the fs readonly, but the
820 	 * in-memory list had better be clean by this point. */
821 	if (!list_empty(&sbi->s_orphan))
822 		dump_orphan_list(sb, sbi);
823 	J_ASSERT(list_empty(&sbi->s_orphan));
824 
825 	invalidate_bdev(sb->s_bdev);
826 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
827 		/*
828 		 * Invalidate the journal device's buffers.  We don't want them
829 		 * floating about in memory - the physical journal device may
830 		 * hotswapped, and it breaks the `ro-after' testing code.
831 		 */
832 		sync_blockdev(sbi->journal_bdev);
833 		invalidate_bdev(sbi->journal_bdev);
834 		ext4_blkdev_remove(sbi);
835 	}
836 	if (sbi->s_mb_cache) {
837 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
838 		sbi->s_mb_cache = NULL;
839 	}
840 	if (sbi->s_mmp_tsk)
841 		kthread_stop(sbi->s_mmp_tsk);
842 	sb->s_fs_info = NULL;
843 	/*
844 	 * Now that we are completely done shutting down the
845 	 * superblock, we need to actually destroy the kobject.
846 	 */
847 	kobject_put(&sbi->s_kobj);
848 	wait_for_completion(&sbi->s_kobj_unregister);
849 	if (sbi->s_chksum_driver)
850 		crypto_free_shash(sbi->s_chksum_driver);
851 	kfree(sbi->s_blockgroup_lock);
852 	kfree(sbi);
853 }
854 
855 static struct kmem_cache *ext4_inode_cachep;
856 
857 /*
858  * Called inside transaction, so use GFP_NOFS
859  */
860 static struct inode *ext4_alloc_inode(struct super_block *sb)
861 {
862 	struct ext4_inode_info *ei;
863 
864 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
865 	if (!ei)
866 		return NULL;
867 
868 	ei->vfs_inode.i_version = 1;
869 	spin_lock_init(&ei->i_raw_lock);
870 	INIT_LIST_HEAD(&ei->i_prealloc_list);
871 	spin_lock_init(&ei->i_prealloc_lock);
872 	ext4_es_init_tree(&ei->i_es_tree);
873 	rwlock_init(&ei->i_es_lock);
874 	INIT_LIST_HEAD(&ei->i_es_list);
875 	ei->i_es_all_nr = 0;
876 	ei->i_es_shk_nr = 0;
877 	ei->i_es_shrink_lblk = 0;
878 	ei->i_reserved_data_blocks = 0;
879 	ei->i_reserved_meta_blocks = 0;
880 	ei->i_allocated_meta_blocks = 0;
881 	ei->i_da_metadata_calc_len = 0;
882 	ei->i_da_metadata_calc_last_lblock = 0;
883 	spin_lock_init(&(ei->i_block_reservation_lock));
884 #ifdef CONFIG_QUOTA
885 	ei->i_reserved_quota = 0;
886 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
887 #endif
888 	ei->jinode = NULL;
889 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
890 	spin_lock_init(&ei->i_completed_io_lock);
891 	ei->i_sync_tid = 0;
892 	ei->i_datasync_tid = 0;
893 	atomic_set(&ei->i_ioend_count, 0);
894 	atomic_set(&ei->i_unwritten, 0);
895 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
896 
897 	return &ei->vfs_inode;
898 }
899 
900 static int ext4_drop_inode(struct inode *inode)
901 {
902 	int drop = generic_drop_inode(inode);
903 
904 	trace_ext4_drop_inode(inode, drop);
905 	return drop;
906 }
907 
908 static void ext4_i_callback(struct rcu_head *head)
909 {
910 	struct inode *inode = container_of(head, struct inode, i_rcu);
911 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
912 }
913 
914 static void ext4_destroy_inode(struct inode *inode)
915 {
916 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
917 		ext4_msg(inode->i_sb, KERN_ERR,
918 			 "Inode %lu (%p): orphan list check failed!",
919 			 inode->i_ino, EXT4_I(inode));
920 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
921 				EXT4_I(inode), sizeof(struct ext4_inode_info),
922 				true);
923 		dump_stack();
924 	}
925 	call_rcu(&inode->i_rcu, ext4_i_callback);
926 }
927 
928 static void init_once(void *foo)
929 {
930 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
931 
932 	INIT_LIST_HEAD(&ei->i_orphan);
933 	init_rwsem(&ei->xattr_sem);
934 	init_rwsem(&ei->i_data_sem);
935 	inode_init_once(&ei->vfs_inode);
936 }
937 
938 static int __init init_inodecache(void)
939 {
940 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
941 					     sizeof(struct ext4_inode_info),
942 					     0, (SLAB_RECLAIM_ACCOUNT|
943 						SLAB_MEM_SPREAD),
944 					     init_once);
945 	if (ext4_inode_cachep == NULL)
946 		return -ENOMEM;
947 	return 0;
948 }
949 
950 static void destroy_inodecache(void)
951 {
952 	/*
953 	 * Make sure all delayed rcu free inodes are flushed before we
954 	 * destroy cache.
955 	 */
956 	rcu_barrier();
957 	kmem_cache_destroy(ext4_inode_cachep);
958 }
959 
960 void ext4_clear_inode(struct inode *inode)
961 {
962 	invalidate_inode_buffers(inode);
963 	clear_inode(inode);
964 	dquot_drop(inode);
965 	ext4_discard_preallocations(inode);
966 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
967 	if (EXT4_I(inode)->jinode) {
968 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
969 					       EXT4_I(inode)->jinode);
970 		jbd2_free_inode(EXT4_I(inode)->jinode);
971 		EXT4_I(inode)->jinode = NULL;
972 	}
973 }
974 
975 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
976 					u64 ino, u32 generation)
977 {
978 	struct inode *inode;
979 
980 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
981 		return ERR_PTR(-ESTALE);
982 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
983 		return ERR_PTR(-ESTALE);
984 
985 	/* iget isn't really right if the inode is currently unallocated!!
986 	 *
987 	 * ext4_read_inode will return a bad_inode if the inode had been
988 	 * deleted, so we should be safe.
989 	 *
990 	 * Currently we don't know the generation for parent directory, so
991 	 * a generation of 0 means "accept any"
992 	 */
993 	inode = ext4_iget_normal(sb, ino);
994 	if (IS_ERR(inode))
995 		return ERR_CAST(inode);
996 	if (generation && inode->i_generation != generation) {
997 		iput(inode);
998 		return ERR_PTR(-ESTALE);
999 	}
1000 
1001 	return inode;
1002 }
1003 
1004 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1005 					int fh_len, int fh_type)
1006 {
1007 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1008 				    ext4_nfs_get_inode);
1009 }
1010 
1011 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1012 					int fh_len, int fh_type)
1013 {
1014 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1015 				    ext4_nfs_get_inode);
1016 }
1017 
1018 /*
1019  * Try to release metadata pages (indirect blocks, directories) which are
1020  * mapped via the block device.  Since these pages could have journal heads
1021  * which would prevent try_to_free_buffers() from freeing them, we must use
1022  * jbd2 layer's try_to_free_buffers() function to release them.
1023  */
1024 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1025 				 gfp_t wait)
1026 {
1027 	journal_t *journal = EXT4_SB(sb)->s_journal;
1028 
1029 	WARN_ON(PageChecked(page));
1030 	if (!page_has_buffers(page))
1031 		return 0;
1032 	if (journal)
1033 		return jbd2_journal_try_to_free_buffers(journal, page,
1034 							wait & ~__GFP_WAIT);
1035 	return try_to_free_buffers(page);
1036 }
1037 
1038 #ifdef CONFIG_QUOTA
1039 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1040 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1041 
1042 static int ext4_write_dquot(struct dquot *dquot);
1043 static int ext4_acquire_dquot(struct dquot *dquot);
1044 static int ext4_release_dquot(struct dquot *dquot);
1045 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1046 static int ext4_write_info(struct super_block *sb, int type);
1047 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1048 			 struct path *path);
1049 static int ext4_quota_off(struct super_block *sb, int type);
1050 static int ext4_quota_on_mount(struct super_block *sb, int type);
1051 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1052 			       size_t len, loff_t off);
1053 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1054 				const char *data, size_t len, loff_t off);
1055 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1056 			     unsigned int flags);
1057 static int ext4_enable_quotas(struct super_block *sb);
1058 
1059 static struct dquot **ext4_get_dquots(struct inode *inode)
1060 {
1061 	return EXT4_I(inode)->i_dquot;
1062 }
1063 
1064 static const struct dquot_operations ext4_quota_operations = {
1065 	.get_reserved_space = ext4_get_reserved_space,
1066 	.write_dquot	= ext4_write_dquot,
1067 	.acquire_dquot	= ext4_acquire_dquot,
1068 	.release_dquot	= ext4_release_dquot,
1069 	.mark_dirty	= ext4_mark_dquot_dirty,
1070 	.write_info	= ext4_write_info,
1071 	.alloc_dquot	= dquot_alloc,
1072 	.destroy_dquot	= dquot_destroy,
1073 };
1074 
1075 static const struct quotactl_ops ext4_qctl_operations = {
1076 	.quota_on	= ext4_quota_on,
1077 	.quota_off	= ext4_quota_off,
1078 	.quota_sync	= dquot_quota_sync,
1079 	.get_info	= dquot_get_dqinfo,
1080 	.set_info	= dquot_set_dqinfo,
1081 	.get_dqblk	= dquot_get_dqblk,
1082 	.set_dqblk	= dquot_set_dqblk
1083 };
1084 #endif
1085 
1086 static const struct super_operations ext4_sops = {
1087 	.alloc_inode	= ext4_alloc_inode,
1088 	.destroy_inode	= ext4_destroy_inode,
1089 	.write_inode	= ext4_write_inode,
1090 	.dirty_inode	= ext4_dirty_inode,
1091 	.drop_inode	= ext4_drop_inode,
1092 	.evict_inode	= ext4_evict_inode,
1093 	.put_super	= ext4_put_super,
1094 	.sync_fs	= ext4_sync_fs,
1095 	.freeze_fs	= ext4_freeze,
1096 	.unfreeze_fs	= ext4_unfreeze,
1097 	.statfs		= ext4_statfs,
1098 	.remount_fs	= ext4_remount,
1099 	.show_options	= ext4_show_options,
1100 #ifdef CONFIG_QUOTA
1101 	.quota_read	= ext4_quota_read,
1102 	.quota_write	= ext4_quota_write,
1103 	.get_dquots	= ext4_get_dquots,
1104 #endif
1105 	.bdev_try_to_free_page = bdev_try_to_free_page,
1106 };
1107 
1108 static const struct export_operations ext4_export_ops = {
1109 	.fh_to_dentry = ext4_fh_to_dentry,
1110 	.fh_to_parent = ext4_fh_to_parent,
1111 	.get_parent = ext4_get_parent,
1112 };
1113 
1114 enum {
1115 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1116 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1117 	Opt_nouid32, Opt_debug, Opt_removed,
1118 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1119 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1120 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1121 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1122 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1123 	Opt_data_err_abort, Opt_data_err_ignore,
1124 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1125 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1126 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1127 	Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1128 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1129 	Opt_lazytime, Opt_nolazytime,
1130 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1131 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1132 	Opt_dioread_nolock, Opt_dioread_lock,
1133 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1134 	Opt_max_dir_size_kb, Opt_nojournal_checksum,
1135 };
1136 
1137 static const match_table_t tokens = {
1138 	{Opt_bsd_df, "bsddf"},
1139 	{Opt_minix_df, "minixdf"},
1140 	{Opt_grpid, "grpid"},
1141 	{Opt_grpid, "bsdgroups"},
1142 	{Opt_nogrpid, "nogrpid"},
1143 	{Opt_nogrpid, "sysvgroups"},
1144 	{Opt_resgid, "resgid=%u"},
1145 	{Opt_resuid, "resuid=%u"},
1146 	{Opt_sb, "sb=%u"},
1147 	{Opt_err_cont, "errors=continue"},
1148 	{Opt_err_panic, "errors=panic"},
1149 	{Opt_err_ro, "errors=remount-ro"},
1150 	{Opt_nouid32, "nouid32"},
1151 	{Opt_debug, "debug"},
1152 	{Opt_removed, "oldalloc"},
1153 	{Opt_removed, "orlov"},
1154 	{Opt_user_xattr, "user_xattr"},
1155 	{Opt_nouser_xattr, "nouser_xattr"},
1156 	{Opt_acl, "acl"},
1157 	{Opt_noacl, "noacl"},
1158 	{Opt_noload, "norecovery"},
1159 	{Opt_noload, "noload"},
1160 	{Opt_removed, "nobh"},
1161 	{Opt_removed, "bh"},
1162 	{Opt_commit, "commit=%u"},
1163 	{Opt_min_batch_time, "min_batch_time=%u"},
1164 	{Opt_max_batch_time, "max_batch_time=%u"},
1165 	{Opt_journal_dev, "journal_dev=%u"},
1166 	{Opt_journal_path, "journal_path=%s"},
1167 	{Opt_journal_checksum, "journal_checksum"},
1168 	{Opt_nojournal_checksum, "nojournal_checksum"},
1169 	{Opt_journal_async_commit, "journal_async_commit"},
1170 	{Opt_abort, "abort"},
1171 	{Opt_data_journal, "data=journal"},
1172 	{Opt_data_ordered, "data=ordered"},
1173 	{Opt_data_writeback, "data=writeback"},
1174 	{Opt_data_err_abort, "data_err=abort"},
1175 	{Opt_data_err_ignore, "data_err=ignore"},
1176 	{Opt_offusrjquota, "usrjquota="},
1177 	{Opt_usrjquota, "usrjquota=%s"},
1178 	{Opt_offgrpjquota, "grpjquota="},
1179 	{Opt_grpjquota, "grpjquota=%s"},
1180 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1181 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1182 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1183 	{Opt_grpquota, "grpquota"},
1184 	{Opt_noquota, "noquota"},
1185 	{Opt_quota, "quota"},
1186 	{Opt_usrquota, "usrquota"},
1187 	{Opt_barrier, "barrier=%u"},
1188 	{Opt_barrier, "barrier"},
1189 	{Opt_nobarrier, "nobarrier"},
1190 	{Opt_i_version, "i_version"},
1191 	{Opt_dax, "dax"},
1192 	{Opt_stripe, "stripe=%u"},
1193 	{Opt_delalloc, "delalloc"},
1194 	{Opt_lazytime, "lazytime"},
1195 	{Opt_nolazytime, "nolazytime"},
1196 	{Opt_nodelalloc, "nodelalloc"},
1197 	{Opt_removed, "mblk_io_submit"},
1198 	{Opt_removed, "nomblk_io_submit"},
1199 	{Opt_block_validity, "block_validity"},
1200 	{Opt_noblock_validity, "noblock_validity"},
1201 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1202 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1203 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1204 	{Opt_auto_da_alloc, "auto_da_alloc"},
1205 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1206 	{Opt_dioread_nolock, "dioread_nolock"},
1207 	{Opt_dioread_lock, "dioread_lock"},
1208 	{Opt_discard, "discard"},
1209 	{Opt_nodiscard, "nodiscard"},
1210 	{Opt_init_itable, "init_itable=%u"},
1211 	{Opt_init_itable, "init_itable"},
1212 	{Opt_noinit_itable, "noinit_itable"},
1213 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1214 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1215 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1216 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1217 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1218 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1219 	{Opt_err, NULL},
1220 };
1221 
1222 static ext4_fsblk_t get_sb_block(void **data)
1223 {
1224 	ext4_fsblk_t	sb_block;
1225 	char		*options = (char *) *data;
1226 
1227 	if (!options || strncmp(options, "sb=", 3) != 0)
1228 		return 1;	/* Default location */
1229 
1230 	options += 3;
1231 	/* TODO: use simple_strtoll with >32bit ext4 */
1232 	sb_block = simple_strtoul(options, &options, 0);
1233 	if (*options && *options != ',') {
1234 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1235 		       (char *) *data);
1236 		return 1;
1237 	}
1238 	if (*options == ',')
1239 		options++;
1240 	*data = (void *) options;
1241 
1242 	return sb_block;
1243 }
1244 
1245 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1246 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1247 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1248 
1249 #ifdef CONFIG_QUOTA
1250 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1251 {
1252 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1253 	char *qname;
1254 	int ret = -1;
1255 
1256 	if (sb_any_quota_loaded(sb) &&
1257 		!sbi->s_qf_names[qtype]) {
1258 		ext4_msg(sb, KERN_ERR,
1259 			"Cannot change journaled "
1260 			"quota options when quota turned on");
1261 		return -1;
1262 	}
1263 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1264 		ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1265 			 "when QUOTA feature is enabled");
1266 		return -1;
1267 	}
1268 	qname = match_strdup(args);
1269 	if (!qname) {
1270 		ext4_msg(sb, KERN_ERR,
1271 			"Not enough memory for storing quotafile name");
1272 		return -1;
1273 	}
1274 	if (sbi->s_qf_names[qtype]) {
1275 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1276 			ret = 1;
1277 		else
1278 			ext4_msg(sb, KERN_ERR,
1279 				 "%s quota file already specified",
1280 				 QTYPE2NAME(qtype));
1281 		goto errout;
1282 	}
1283 	if (strchr(qname, '/')) {
1284 		ext4_msg(sb, KERN_ERR,
1285 			"quotafile must be on filesystem root");
1286 		goto errout;
1287 	}
1288 	sbi->s_qf_names[qtype] = qname;
1289 	set_opt(sb, QUOTA);
1290 	return 1;
1291 errout:
1292 	kfree(qname);
1293 	return ret;
1294 }
1295 
1296 static int clear_qf_name(struct super_block *sb, int qtype)
1297 {
1298 
1299 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1300 
1301 	if (sb_any_quota_loaded(sb) &&
1302 		sbi->s_qf_names[qtype]) {
1303 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1304 			" when quota turned on");
1305 		return -1;
1306 	}
1307 	kfree(sbi->s_qf_names[qtype]);
1308 	sbi->s_qf_names[qtype] = NULL;
1309 	return 1;
1310 }
1311 #endif
1312 
1313 #define MOPT_SET	0x0001
1314 #define MOPT_CLEAR	0x0002
1315 #define MOPT_NOSUPPORT	0x0004
1316 #define MOPT_EXPLICIT	0x0008
1317 #define MOPT_CLEAR_ERR	0x0010
1318 #define MOPT_GTE0	0x0020
1319 #ifdef CONFIG_QUOTA
1320 #define MOPT_Q		0
1321 #define MOPT_QFMT	0x0040
1322 #else
1323 #define MOPT_Q		MOPT_NOSUPPORT
1324 #define MOPT_QFMT	MOPT_NOSUPPORT
1325 #endif
1326 #define MOPT_DATAJ	0x0080
1327 #define MOPT_NO_EXT2	0x0100
1328 #define MOPT_NO_EXT3	0x0200
1329 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1330 #define MOPT_STRING	0x0400
1331 
1332 static const struct mount_opts {
1333 	int	token;
1334 	int	mount_opt;
1335 	int	flags;
1336 } ext4_mount_opts[] = {
1337 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1338 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1339 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1340 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1341 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1342 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1343 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1344 	 MOPT_EXT4_ONLY | MOPT_SET},
1345 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1346 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1347 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1348 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1349 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1350 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1351 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1352 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1353 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1354 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1355 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1356 	 MOPT_EXT4_ONLY | MOPT_SET},
1357 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1358 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1359 	 MOPT_EXT4_ONLY | MOPT_SET},
1360 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1361 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1362 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1363 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1364 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1365 	 MOPT_NO_EXT2 | MOPT_SET},
1366 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1367 	 MOPT_NO_EXT2 | MOPT_CLEAR},
1368 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1369 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1370 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1371 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1372 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1373 	{Opt_commit, 0, MOPT_GTE0},
1374 	{Opt_max_batch_time, 0, MOPT_GTE0},
1375 	{Opt_min_batch_time, 0, MOPT_GTE0},
1376 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1377 	{Opt_init_itable, 0, MOPT_GTE0},
1378 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1379 	{Opt_stripe, 0, MOPT_GTE0},
1380 	{Opt_resuid, 0, MOPT_GTE0},
1381 	{Opt_resgid, 0, MOPT_GTE0},
1382 	{Opt_journal_dev, 0, MOPT_GTE0},
1383 	{Opt_journal_path, 0, MOPT_STRING},
1384 	{Opt_journal_ioprio, 0, MOPT_GTE0},
1385 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1386 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1387 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1388 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1389 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1390 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1391 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1392 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1393 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1394 #else
1395 	{Opt_acl, 0, MOPT_NOSUPPORT},
1396 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1397 #endif
1398 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1399 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1400 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1401 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1402 							MOPT_SET | MOPT_Q},
1403 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1404 							MOPT_SET | MOPT_Q},
1405 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1406 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1407 	{Opt_usrjquota, 0, MOPT_Q},
1408 	{Opt_grpjquota, 0, MOPT_Q},
1409 	{Opt_offusrjquota, 0, MOPT_Q},
1410 	{Opt_offgrpjquota, 0, MOPT_Q},
1411 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1412 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1413 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1414 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1415 	{Opt_err, 0, 0}
1416 };
1417 
1418 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1419 			    substring_t *args, unsigned long *journal_devnum,
1420 			    unsigned int *journal_ioprio, int is_remount)
1421 {
1422 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1423 	const struct mount_opts *m;
1424 	kuid_t uid;
1425 	kgid_t gid;
1426 	int arg = 0;
1427 
1428 #ifdef CONFIG_QUOTA
1429 	if (token == Opt_usrjquota)
1430 		return set_qf_name(sb, USRQUOTA, &args[0]);
1431 	else if (token == Opt_grpjquota)
1432 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1433 	else if (token == Opt_offusrjquota)
1434 		return clear_qf_name(sb, USRQUOTA);
1435 	else if (token == Opt_offgrpjquota)
1436 		return clear_qf_name(sb, GRPQUOTA);
1437 #endif
1438 	switch (token) {
1439 	case Opt_noacl:
1440 	case Opt_nouser_xattr:
1441 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1442 		break;
1443 	case Opt_sb:
1444 		return 1;	/* handled by get_sb_block() */
1445 	case Opt_removed:
1446 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1447 		return 1;
1448 	case Opt_abort:
1449 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1450 		return 1;
1451 	case Opt_i_version:
1452 		sb->s_flags |= MS_I_VERSION;
1453 		return 1;
1454 	case Opt_lazytime:
1455 		sb->s_flags |= MS_LAZYTIME;
1456 		return 1;
1457 	case Opt_nolazytime:
1458 		sb->s_flags &= ~MS_LAZYTIME;
1459 		return 1;
1460 	}
1461 
1462 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1463 		if (token == m->token)
1464 			break;
1465 
1466 	if (m->token == Opt_err) {
1467 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1468 			 "or missing value", opt);
1469 		return -1;
1470 	}
1471 
1472 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1473 		ext4_msg(sb, KERN_ERR,
1474 			 "Mount option \"%s\" incompatible with ext2", opt);
1475 		return -1;
1476 	}
1477 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1478 		ext4_msg(sb, KERN_ERR,
1479 			 "Mount option \"%s\" incompatible with ext3", opt);
1480 		return -1;
1481 	}
1482 
1483 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1484 		return -1;
1485 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1486 		return -1;
1487 	if (m->flags & MOPT_EXPLICIT)
1488 		set_opt2(sb, EXPLICIT_DELALLOC);
1489 	if (m->flags & MOPT_CLEAR_ERR)
1490 		clear_opt(sb, ERRORS_MASK);
1491 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1492 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1493 			 "options when quota turned on");
1494 		return -1;
1495 	}
1496 
1497 	if (m->flags & MOPT_NOSUPPORT) {
1498 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1499 	} else if (token == Opt_commit) {
1500 		if (arg == 0)
1501 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1502 		sbi->s_commit_interval = HZ * arg;
1503 	} else if (token == Opt_max_batch_time) {
1504 		sbi->s_max_batch_time = arg;
1505 	} else if (token == Opt_min_batch_time) {
1506 		sbi->s_min_batch_time = arg;
1507 	} else if (token == Opt_inode_readahead_blks) {
1508 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1509 			ext4_msg(sb, KERN_ERR,
1510 				 "EXT4-fs: inode_readahead_blks must be "
1511 				 "0 or a power of 2 smaller than 2^31");
1512 			return -1;
1513 		}
1514 		sbi->s_inode_readahead_blks = arg;
1515 	} else if (token == Opt_init_itable) {
1516 		set_opt(sb, INIT_INODE_TABLE);
1517 		if (!args->from)
1518 			arg = EXT4_DEF_LI_WAIT_MULT;
1519 		sbi->s_li_wait_mult = arg;
1520 	} else if (token == Opt_max_dir_size_kb) {
1521 		sbi->s_max_dir_size_kb = arg;
1522 	} else if (token == Opt_stripe) {
1523 		sbi->s_stripe = arg;
1524 	} else if (token == Opt_resuid) {
1525 		uid = make_kuid(current_user_ns(), arg);
1526 		if (!uid_valid(uid)) {
1527 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1528 			return -1;
1529 		}
1530 		sbi->s_resuid = uid;
1531 	} else if (token == Opt_resgid) {
1532 		gid = make_kgid(current_user_ns(), arg);
1533 		if (!gid_valid(gid)) {
1534 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1535 			return -1;
1536 		}
1537 		sbi->s_resgid = gid;
1538 	} else if (token == Opt_journal_dev) {
1539 		if (is_remount) {
1540 			ext4_msg(sb, KERN_ERR,
1541 				 "Cannot specify journal on remount");
1542 			return -1;
1543 		}
1544 		*journal_devnum = arg;
1545 	} else if (token == Opt_journal_path) {
1546 		char *journal_path;
1547 		struct inode *journal_inode;
1548 		struct path path;
1549 		int error;
1550 
1551 		if (is_remount) {
1552 			ext4_msg(sb, KERN_ERR,
1553 				 "Cannot specify journal on remount");
1554 			return -1;
1555 		}
1556 		journal_path = match_strdup(&args[0]);
1557 		if (!journal_path) {
1558 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1559 				"journal device string");
1560 			return -1;
1561 		}
1562 
1563 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1564 		if (error) {
1565 			ext4_msg(sb, KERN_ERR, "error: could not find "
1566 				"journal device path: error %d", error);
1567 			kfree(journal_path);
1568 			return -1;
1569 		}
1570 
1571 		journal_inode = path.dentry->d_inode;
1572 		if (!S_ISBLK(journal_inode->i_mode)) {
1573 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1574 				"is not a block device", journal_path);
1575 			path_put(&path);
1576 			kfree(journal_path);
1577 			return -1;
1578 		}
1579 
1580 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1581 		path_put(&path);
1582 		kfree(journal_path);
1583 	} else if (token == Opt_journal_ioprio) {
1584 		if (arg > 7) {
1585 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1586 				 " (must be 0-7)");
1587 			return -1;
1588 		}
1589 		*journal_ioprio =
1590 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1591 	} else if (m->flags & MOPT_DATAJ) {
1592 		if (is_remount) {
1593 			if (!sbi->s_journal)
1594 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1595 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1596 				ext4_msg(sb, KERN_ERR,
1597 					 "Cannot change data mode on remount");
1598 				return -1;
1599 			}
1600 		} else {
1601 			clear_opt(sb, DATA_FLAGS);
1602 			sbi->s_mount_opt |= m->mount_opt;
1603 		}
1604 #ifdef CONFIG_QUOTA
1605 	} else if (m->flags & MOPT_QFMT) {
1606 		if (sb_any_quota_loaded(sb) &&
1607 		    sbi->s_jquota_fmt != m->mount_opt) {
1608 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1609 				 "quota options when quota turned on");
1610 			return -1;
1611 		}
1612 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1613 					       EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1614 			ext4_msg(sb, KERN_ERR,
1615 				 "Cannot set journaled quota options "
1616 				 "when QUOTA feature is enabled");
1617 			return -1;
1618 		}
1619 		sbi->s_jquota_fmt = m->mount_opt;
1620 #endif
1621 #ifndef CONFIG_FS_DAX
1622 	} else if (token == Opt_dax) {
1623 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1624 		return -1;
1625 #endif
1626 	} else {
1627 		if (!args->from)
1628 			arg = 1;
1629 		if (m->flags & MOPT_CLEAR)
1630 			arg = !arg;
1631 		else if (unlikely(!(m->flags & MOPT_SET))) {
1632 			ext4_msg(sb, KERN_WARNING,
1633 				 "buggy handling of option %s", opt);
1634 			WARN_ON(1);
1635 			return -1;
1636 		}
1637 		if (arg != 0)
1638 			sbi->s_mount_opt |= m->mount_opt;
1639 		else
1640 			sbi->s_mount_opt &= ~m->mount_opt;
1641 	}
1642 	return 1;
1643 }
1644 
1645 static int parse_options(char *options, struct super_block *sb,
1646 			 unsigned long *journal_devnum,
1647 			 unsigned int *journal_ioprio,
1648 			 int is_remount)
1649 {
1650 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1651 	char *p;
1652 	substring_t args[MAX_OPT_ARGS];
1653 	int token;
1654 
1655 	if (!options)
1656 		return 1;
1657 
1658 	while ((p = strsep(&options, ",")) != NULL) {
1659 		if (!*p)
1660 			continue;
1661 		/*
1662 		 * Initialize args struct so we know whether arg was
1663 		 * found; some options take optional arguments.
1664 		 */
1665 		args[0].to = args[0].from = NULL;
1666 		token = match_token(p, tokens, args);
1667 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1668 				     journal_ioprio, is_remount) < 0)
1669 			return 0;
1670 	}
1671 #ifdef CONFIG_QUOTA
1672 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1673 	    (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1674 		ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1675 			 "feature is enabled");
1676 		return 0;
1677 	}
1678 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1679 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1680 			clear_opt(sb, USRQUOTA);
1681 
1682 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1683 			clear_opt(sb, GRPQUOTA);
1684 
1685 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1686 			ext4_msg(sb, KERN_ERR, "old and new quota "
1687 					"format mixing");
1688 			return 0;
1689 		}
1690 
1691 		if (!sbi->s_jquota_fmt) {
1692 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1693 					"not specified");
1694 			return 0;
1695 		}
1696 	}
1697 #endif
1698 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1699 		int blocksize =
1700 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1701 
1702 		if (blocksize < PAGE_CACHE_SIZE) {
1703 			ext4_msg(sb, KERN_ERR, "can't mount with "
1704 				 "dioread_nolock if block size != PAGE_SIZE");
1705 			return 0;
1706 		}
1707 	}
1708 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1709 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1710 		ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1711 			 "in data=ordered mode");
1712 		return 0;
1713 	}
1714 	return 1;
1715 }
1716 
1717 static inline void ext4_show_quota_options(struct seq_file *seq,
1718 					   struct super_block *sb)
1719 {
1720 #if defined(CONFIG_QUOTA)
1721 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1722 
1723 	if (sbi->s_jquota_fmt) {
1724 		char *fmtname = "";
1725 
1726 		switch (sbi->s_jquota_fmt) {
1727 		case QFMT_VFS_OLD:
1728 			fmtname = "vfsold";
1729 			break;
1730 		case QFMT_VFS_V0:
1731 			fmtname = "vfsv0";
1732 			break;
1733 		case QFMT_VFS_V1:
1734 			fmtname = "vfsv1";
1735 			break;
1736 		}
1737 		seq_printf(seq, ",jqfmt=%s", fmtname);
1738 	}
1739 
1740 	if (sbi->s_qf_names[USRQUOTA])
1741 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1742 
1743 	if (sbi->s_qf_names[GRPQUOTA])
1744 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1745 #endif
1746 }
1747 
1748 static const char *token2str(int token)
1749 {
1750 	const struct match_token *t;
1751 
1752 	for (t = tokens; t->token != Opt_err; t++)
1753 		if (t->token == token && !strchr(t->pattern, '='))
1754 			break;
1755 	return t->pattern;
1756 }
1757 
1758 /*
1759  * Show an option if
1760  *  - it's set to a non-default value OR
1761  *  - if the per-sb default is different from the global default
1762  */
1763 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1764 			      int nodefs)
1765 {
1766 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1767 	struct ext4_super_block *es = sbi->s_es;
1768 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1769 	const struct mount_opts *m;
1770 	char sep = nodefs ? '\n' : ',';
1771 
1772 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1773 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1774 
1775 	if (sbi->s_sb_block != 1)
1776 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1777 
1778 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1779 		int want_set = m->flags & MOPT_SET;
1780 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1781 		    (m->flags & MOPT_CLEAR_ERR))
1782 			continue;
1783 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1784 			continue; /* skip if same as the default */
1785 		if ((want_set &&
1786 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1787 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1788 			continue; /* select Opt_noFoo vs Opt_Foo */
1789 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1790 	}
1791 
1792 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1793 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1794 		SEQ_OPTS_PRINT("resuid=%u",
1795 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1796 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1797 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1798 		SEQ_OPTS_PRINT("resgid=%u",
1799 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1800 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1801 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1802 		SEQ_OPTS_PUTS("errors=remount-ro");
1803 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1804 		SEQ_OPTS_PUTS("errors=continue");
1805 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1806 		SEQ_OPTS_PUTS("errors=panic");
1807 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1808 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1809 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1810 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1811 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1812 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1813 	if (sb->s_flags & MS_I_VERSION)
1814 		SEQ_OPTS_PUTS("i_version");
1815 	if (nodefs || sbi->s_stripe)
1816 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1817 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1818 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1819 			SEQ_OPTS_PUTS("data=journal");
1820 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1821 			SEQ_OPTS_PUTS("data=ordered");
1822 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1823 			SEQ_OPTS_PUTS("data=writeback");
1824 	}
1825 	if (nodefs ||
1826 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1827 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1828 			       sbi->s_inode_readahead_blks);
1829 
1830 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1831 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1832 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1833 	if (nodefs || sbi->s_max_dir_size_kb)
1834 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1835 
1836 	ext4_show_quota_options(seq, sb);
1837 	return 0;
1838 }
1839 
1840 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1841 {
1842 	return _ext4_show_options(seq, root->d_sb, 0);
1843 }
1844 
1845 static int options_seq_show(struct seq_file *seq, void *offset)
1846 {
1847 	struct super_block *sb = seq->private;
1848 	int rc;
1849 
1850 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1851 	rc = _ext4_show_options(seq, sb, 1);
1852 	seq_puts(seq, "\n");
1853 	return rc;
1854 }
1855 
1856 static int options_open_fs(struct inode *inode, struct file *file)
1857 {
1858 	return single_open(file, options_seq_show, PDE_DATA(inode));
1859 }
1860 
1861 static const struct file_operations ext4_seq_options_fops = {
1862 	.owner = THIS_MODULE,
1863 	.open = options_open_fs,
1864 	.read = seq_read,
1865 	.llseek = seq_lseek,
1866 	.release = single_release,
1867 };
1868 
1869 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1870 			    int read_only)
1871 {
1872 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1873 	int res = 0;
1874 
1875 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1876 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1877 			 "forcing read-only mode");
1878 		res = MS_RDONLY;
1879 	}
1880 	if (read_only)
1881 		goto done;
1882 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1883 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1884 			 "running e2fsck is recommended");
1885 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
1886 		ext4_msg(sb, KERN_WARNING,
1887 			 "warning: mounting fs with errors, "
1888 			 "running e2fsck is recommended");
1889 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1890 		 le16_to_cpu(es->s_mnt_count) >=
1891 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1892 		ext4_msg(sb, KERN_WARNING,
1893 			 "warning: maximal mount count reached, "
1894 			 "running e2fsck is recommended");
1895 	else if (le32_to_cpu(es->s_checkinterval) &&
1896 		(le32_to_cpu(es->s_lastcheck) +
1897 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1898 		ext4_msg(sb, KERN_WARNING,
1899 			 "warning: checktime reached, "
1900 			 "running e2fsck is recommended");
1901 	if (!sbi->s_journal)
1902 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1903 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1904 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1905 	le16_add_cpu(&es->s_mnt_count, 1);
1906 	es->s_mtime = cpu_to_le32(get_seconds());
1907 	ext4_update_dynamic_rev(sb);
1908 	if (sbi->s_journal)
1909 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1910 
1911 	ext4_commit_super(sb, 1);
1912 done:
1913 	if (test_opt(sb, DEBUG))
1914 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1915 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1916 			sb->s_blocksize,
1917 			sbi->s_groups_count,
1918 			EXT4_BLOCKS_PER_GROUP(sb),
1919 			EXT4_INODES_PER_GROUP(sb),
1920 			sbi->s_mount_opt, sbi->s_mount_opt2);
1921 
1922 	cleancache_init_fs(sb);
1923 	return res;
1924 }
1925 
1926 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1927 {
1928 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1929 	struct flex_groups *new_groups;
1930 	int size;
1931 
1932 	if (!sbi->s_log_groups_per_flex)
1933 		return 0;
1934 
1935 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
1936 	if (size <= sbi->s_flex_groups_allocated)
1937 		return 0;
1938 
1939 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1940 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1941 	if (!new_groups) {
1942 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1943 			 size / (int) sizeof(struct flex_groups));
1944 		return -ENOMEM;
1945 	}
1946 
1947 	if (sbi->s_flex_groups) {
1948 		memcpy(new_groups, sbi->s_flex_groups,
1949 		       (sbi->s_flex_groups_allocated *
1950 			sizeof(struct flex_groups)));
1951 		kvfree(sbi->s_flex_groups);
1952 	}
1953 	sbi->s_flex_groups = new_groups;
1954 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1955 	return 0;
1956 }
1957 
1958 static int ext4_fill_flex_info(struct super_block *sb)
1959 {
1960 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1961 	struct ext4_group_desc *gdp = NULL;
1962 	ext4_group_t flex_group;
1963 	int i, err;
1964 
1965 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1966 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1967 		sbi->s_log_groups_per_flex = 0;
1968 		return 1;
1969 	}
1970 
1971 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1972 	if (err)
1973 		goto failed;
1974 
1975 	for (i = 0; i < sbi->s_groups_count; i++) {
1976 		gdp = ext4_get_group_desc(sb, i, NULL);
1977 
1978 		flex_group = ext4_flex_group(sbi, i);
1979 		atomic_add(ext4_free_inodes_count(sb, gdp),
1980 			   &sbi->s_flex_groups[flex_group].free_inodes);
1981 		atomic64_add(ext4_free_group_clusters(sb, gdp),
1982 			     &sbi->s_flex_groups[flex_group].free_clusters);
1983 		atomic_add(ext4_used_dirs_count(sb, gdp),
1984 			   &sbi->s_flex_groups[flex_group].used_dirs);
1985 	}
1986 
1987 	return 1;
1988 failed:
1989 	return 0;
1990 }
1991 
1992 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1993 				   struct ext4_group_desc *gdp)
1994 {
1995 	int offset;
1996 	__u16 crc = 0;
1997 	__le32 le_group = cpu_to_le32(block_group);
1998 
1999 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2000 		/* Use new metadata_csum algorithm */
2001 		__le16 save_csum;
2002 		__u32 csum32;
2003 
2004 		save_csum = gdp->bg_checksum;
2005 		gdp->bg_checksum = 0;
2006 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2007 				     sizeof(le_group));
2008 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2009 				     sbi->s_desc_size);
2010 		gdp->bg_checksum = save_csum;
2011 
2012 		crc = csum32 & 0xFFFF;
2013 		goto out;
2014 	}
2015 
2016 	/* old crc16 code */
2017 	if (!(sbi->s_es->s_feature_ro_compat &
2018 	      cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
2019 		return 0;
2020 
2021 	offset = offsetof(struct ext4_group_desc, bg_checksum);
2022 
2023 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2024 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2025 	crc = crc16(crc, (__u8 *)gdp, offset);
2026 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2027 	/* for checksum of struct ext4_group_desc do the rest...*/
2028 	if ((sbi->s_es->s_feature_incompat &
2029 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2030 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2031 		crc = crc16(crc, (__u8 *)gdp + offset,
2032 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2033 				offset);
2034 
2035 out:
2036 	return cpu_to_le16(crc);
2037 }
2038 
2039 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2040 				struct ext4_group_desc *gdp)
2041 {
2042 	if (ext4_has_group_desc_csum(sb) &&
2043 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2044 						      block_group, gdp)))
2045 		return 0;
2046 
2047 	return 1;
2048 }
2049 
2050 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2051 			      struct ext4_group_desc *gdp)
2052 {
2053 	if (!ext4_has_group_desc_csum(sb))
2054 		return;
2055 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2056 }
2057 
2058 /* Called at mount-time, super-block is locked */
2059 static int ext4_check_descriptors(struct super_block *sb,
2060 				  ext4_group_t *first_not_zeroed)
2061 {
2062 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2063 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2064 	ext4_fsblk_t last_block;
2065 	ext4_fsblk_t block_bitmap;
2066 	ext4_fsblk_t inode_bitmap;
2067 	ext4_fsblk_t inode_table;
2068 	int flexbg_flag = 0;
2069 	ext4_group_t i, grp = sbi->s_groups_count;
2070 
2071 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2072 		flexbg_flag = 1;
2073 
2074 	ext4_debug("Checking group descriptors");
2075 
2076 	for (i = 0; i < sbi->s_groups_count; i++) {
2077 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2078 
2079 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2080 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2081 		else
2082 			last_block = first_block +
2083 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2084 
2085 		if ((grp == sbi->s_groups_count) &&
2086 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2087 			grp = i;
2088 
2089 		block_bitmap = ext4_block_bitmap(sb, gdp);
2090 		if (block_bitmap < first_block || block_bitmap > last_block) {
2091 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2092 			       "Block bitmap for group %u not in group "
2093 			       "(block %llu)!", i, block_bitmap);
2094 			return 0;
2095 		}
2096 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2097 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2098 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2099 			       "Inode bitmap for group %u not in group "
2100 			       "(block %llu)!", i, inode_bitmap);
2101 			return 0;
2102 		}
2103 		inode_table = ext4_inode_table(sb, gdp);
2104 		if (inode_table < first_block ||
2105 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2106 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2107 			       "Inode table for group %u not in group "
2108 			       "(block %llu)!", i, inode_table);
2109 			return 0;
2110 		}
2111 		ext4_lock_group(sb, i);
2112 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2113 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2114 				 "Checksum for group %u failed (%u!=%u)",
2115 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2116 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2117 			if (!(sb->s_flags & MS_RDONLY)) {
2118 				ext4_unlock_group(sb, i);
2119 				return 0;
2120 			}
2121 		}
2122 		ext4_unlock_group(sb, i);
2123 		if (!flexbg_flag)
2124 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2125 	}
2126 	if (NULL != first_not_zeroed)
2127 		*first_not_zeroed = grp;
2128 	return 1;
2129 }
2130 
2131 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2132  * the superblock) which were deleted from all directories, but held open by
2133  * a process at the time of a crash.  We walk the list and try to delete these
2134  * inodes at recovery time (only with a read-write filesystem).
2135  *
2136  * In order to keep the orphan inode chain consistent during traversal (in
2137  * case of crash during recovery), we link each inode into the superblock
2138  * orphan list_head and handle it the same way as an inode deletion during
2139  * normal operation (which journals the operations for us).
2140  *
2141  * We only do an iget() and an iput() on each inode, which is very safe if we
2142  * accidentally point at an in-use or already deleted inode.  The worst that
2143  * can happen in this case is that we get a "bit already cleared" message from
2144  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2145  * e2fsck was run on this filesystem, and it must have already done the orphan
2146  * inode cleanup for us, so we can safely abort without any further action.
2147  */
2148 static void ext4_orphan_cleanup(struct super_block *sb,
2149 				struct ext4_super_block *es)
2150 {
2151 	unsigned int s_flags = sb->s_flags;
2152 	int nr_orphans = 0, nr_truncates = 0;
2153 #ifdef CONFIG_QUOTA
2154 	int i;
2155 #endif
2156 	if (!es->s_last_orphan) {
2157 		jbd_debug(4, "no orphan inodes to clean up\n");
2158 		return;
2159 	}
2160 
2161 	if (bdev_read_only(sb->s_bdev)) {
2162 		ext4_msg(sb, KERN_ERR, "write access "
2163 			"unavailable, skipping orphan cleanup");
2164 		return;
2165 	}
2166 
2167 	/* Check if feature set would not allow a r/w mount */
2168 	if (!ext4_feature_set_ok(sb, 0)) {
2169 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2170 			 "unknown ROCOMPAT features");
2171 		return;
2172 	}
2173 
2174 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2175 		/* don't clear list on RO mount w/ errors */
2176 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2177 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2178 				  "clearing orphan list.\n");
2179 			es->s_last_orphan = 0;
2180 		}
2181 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2182 		return;
2183 	}
2184 
2185 	if (s_flags & MS_RDONLY) {
2186 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2187 		sb->s_flags &= ~MS_RDONLY;
2188 	}
2189 #ifdef CONFIG_QUOTA
2190 	/* Needed for iput() to work correctly and not trash data */
2191 	sb->s_flags |= MS_ACTIVE;
2192 	/* Turn on quotas so that they are updated correctly */
2193 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2194 		if (EXT4_SB(sb)->s_qf_names[i]) {
2195 			int ret = ext4_quota_on_mount(sb, i);
2196 			if (ret < 0)
2197 				ext4_msg(sb, KERN_ERR,
2198 					"Cannot turn on journaled "
2199 					"quota: error %d", ret);
2200 		}
2201 	}
2202 #endif
2203 
2204 	while (es->s_last_orphan) {
2205 		struct inode *inode;
2206 
2207 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2208 		if (IS_ERR(inode)) {
2209 			es->s_last_orphan = 0;
2210 			break;
2211 		}
2212 
2213 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2214 		dquot_initialize(inode);
2215 		if (inode->i_nlink) {
2216 			if (test_opt(sb, DEBUG))
2217 				ext4_msg(sb, KERN_DEBUG,
2218 					"%s: truncating inode %lu to %lld bytes",
2219 					__func__, inode->i_ino, inode->i_size);
2220 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2221 				  inode->i_ino, inode->i_size);
2222 			mutex_lock(&inode->i_mutex);
2223 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2224 			ext4_truncate(inode);
2225 			mutex_unlock(&inode->i_mutex);
2226 			nr_truncates++;
2227 		} else {
2228 			if (test_opt(sb, DEBUG))
2229 				ext4_msg(sb, KERN_DEBUG,
2230 					"%s: deleting unreferenced inode %lu",
2231 					__func__, inode->i_ino);
2232 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2233 				  inode->i_ino);
2234 			nr_orphans++;
2235 		}
2236 		iput(inode);  /* The delete magic happens here! */
2237 	}
2238 
2239 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2240 
2241 	if (nr_orphans)
2242 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2243 		       PLURAL(nr_orphans));
2244 	if (nr_truncates)
2245 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2246 		       PLURAL(nr_truncates));
2247 #ifdef CONFIG_QUOTA
2248 	/* Turn quotas off */
2249 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2250 		if (sb_dqopt(sb)->files[i])
2251 			dquot_quota_off(sb, i);
2252 	}
2253 #endif
2254 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2255 }
2256 
2257 /*
2258  * Maximal extent format file size.
2259  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2260  * extent format containers, within a sector_t, and within i_blocks
2261  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2262  * so that won't be a limiting factor.
2263  *
2264  * However there is other limiting factor. We do store extents in the form
2265  * of starting block and length, hence the resulting length of the extent
2266  * covering maximum file size must fit into on-disk format containers as
2267  * well. Given that length is always by 1 unit bigger than max unit (because
2268  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2269  *
2270  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2271  */
2272 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2273 {
2274 	loff_t res;
2275 	loff_t upper_limit = MAX_LFS_FILESIZE;
2276 
2277 	/* small i_blocks in vfs inode? */
2278 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2279 		/*
2280 		 * CONFIG_LBDAF is not enabled implies the inode
2281 		 * i_block represent total blocks in 512 bytes
2282 		 * 32 == size of vfs inode i_blocks * 8
2283 		 */
2284 		upper_limit = (1LL << 32) - 1;
2285 
2286 		/* total blocks in file system block size */
2287 		upper_limit >>= (blkbits - 9);
2288 		upper_limit <<= blkbits;
2289 	}
2290 
2291 	/*
2292 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2293 	 * by one fs block, so ee_len can cover the extent of maximum file
2294 	 * size
2295 	 */
2296 	res = (1LL << 32) - 1;
2297 	res <<= blkbits;
2298 
2299 	/* Sanity check against vm- & vfs- imposed limits */
2300 	if (res > upper_limit)
2301 		res = upper_limit;
2302 
2303 	return res;
2304 }
2305 
2306 /*
2307  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2308  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2309  * We need to be 1 filesystem block less than the 2^48 sector limit.
2310  */
2311 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2312 {
2313 	loff_t res = EXT4_NDIR_BLOCKS;
2314 	int meta_blocks;
2315 	loff_t upper_limit;
2316 	/* This is calculated to be the largest file size for a dense, block
2317 	 * mapped file such that the file's total number of 512-byte sectors,
2318 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2319 	 *
2320 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2321 	 * number of 512-byte sectors of the file.
2322 	 */
2323 
2324 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2325 		/*
2326 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2327 		 * the inode i_block field represents total file blocks in
2328 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2329 		 */
2330 		upper_limit = (1LL << 32) - 1;
2331 
2332 		/* total blocks in file system block size */
2333 		upper_limit >>= (bits - 9);
2334 
2335 	} else {
2336 		/*
2337 		 * We use 48 bit ext4_inode i_blocks
2338 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2339 		 * represent total number of blocks in
2340 		 * file system block size
2341 		 */
2342 		upper_limit = (1LL << 48) - 1;
2343 
2344 	}
2345 
2346 	/* indirect blocks */
2347 	meta_blocks = 1;
2348 	/* double indirect blocks */
2349 	meta_blocks += 1 + (1LL << (bits-2));
2350 	/* tripple indirect blocks */
2351 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2352 
2353 	upper_limit -= meta_blocks;
2354 	upper_limit <<= bits;
2355 
2356 	res += 1LL << (bits-2);
2357 	res += 1LL << (2*(bits-2));
2358 	res += 1LL << (3*(bits-2));
2359 	res <<= bits;
2360 	if (res > upper_limit)
2361 		res = upper_limit;
2362 
2363 	if (res > MAX_LFS_FILESIZE)
2364 		res = MAX_LFS_FILESIZE;
2365 
2366 	return res;
2367 }
2368 
2369 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2370 				   ext4_fsblk_t logical_sb_block, int nr)
2371 {
2372 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2373 	ext4_group_t bg, first_meta_bg;
2374 	int has_super = 0;
2375 
2376 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2377 
2378 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2379 	    nr < first_meta_bg)
2380 		return logical_sb_block + nr + 1;
2381 	bg = sbi->s_desc_per_block * nr;
2382 	if (ext4_bg_has_super(sb, bg))
2383 		has_super = 1;
2384 
2385 	/*
2386 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2387 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2388 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2389 	 * compensate.
2390 	 */
2391 	if (sb->s_blocksize == 1024 && nr == 0 &&
2392 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2393 		has_super++;
2394 
2395 	return (has_super + ext4_group_first_block_no(sb, bg));
2396 }
2397 
2398 /**
2399  * ext4_get_stripe_size: Get the stripe size.
2400  * @sbi: In memory super block info
2401  *
2402  * If we have specified it via mount option, then
2403  * use the mount option value. If the value specified at mount time is
2404  * greater than the blocks per group use the super block value.
2405  * If the super block value is greater than blocks per group return 0.
2406  * Allocator needs it be less than blocks per group.
2407  *
2408  */
2409 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2410 {
2411 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2412 	unsigned long stripe_width =
2413 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2414 	int ret;
2415 
2416 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2417 		ret = sbi->s_stripe;
2418 	else if (stripe_width <= sbi->s_blocks_per_group)
2419 		ret = stripe_width;
2420 	else if (stride <= sbi->s_blocks_per_group)
2421 		ret = stride;
2422 	else
2423 		ret = 0;
2424 
2425 	/*
2426 	 * If the stripe width is 1, this makes no sense and
2427 	 * we set it to 0 to turn off stripe handling code.
2428 	 */
2429 	if (ret <= 1)
2430 		ret = 0;
2431 
2432 	return ret;
2433 }
2434 
2435 /* sysfs supprt */
2436 
2437 struct ext4_attr {
2438 	struct attribute attr;
2439 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2440 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2441 			 const char *, size_t);
2442 	union {
2443 		int offset;
2444 		int deprecated_val;
2445 	} u;
2446 };
2447 
2448 static int parse_strtoull(const char *buf,
2449 		unsigned long long max, unsigned long long *value)
2450 {
2451 	int ret;
2452 
2453 	ret = kstrtoull(skip_spaces(buf), 0, value);
2454 	if (!ret && *value > max)
2455 		ret = -EINVAL;
2456 	return ret;
2457 }
2458 
2459 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2460 					      struct ext4_sb_info *sbi,
2461 					      char *buf)
2462 {
2463 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2464 		(s64) EXT4_C2B(sbi,
2465 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2466 }
2467 
2468 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2469 					 struct ext4_sb_info *sbi, char *buf)
2470 {
2471 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2472 
2473 	if (!sb->s_bdev->bd_part)
2474 		return snprintf(buf, PAGE_SIZE, "0\n");
2475 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2476 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2477 			 sbi->s_sectors_written_start) >> 1);
2478 }
2479 
2480 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2481 					  struct ext4_sb_info *sbi, char *buf)
2482 {
2483 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2484 
2485 	if (!sb->s_bdev->bd_part)
2486 		return snprintf(buf, PAGE_SIZE, "0\n");
2487 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2488 			(unsigned long long)(sbi->s_kbytes_written +
2489 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2490 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2491 }
2492 
2493 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2494 					  struct ext4_sb_info *sbi,
2495 					  const char *buf, size_t count)
2496 {
2497 	unsigned long t;
2498 	int ret;
2499 
2500 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2501 	if (ret)
2502 		return ret;
2503 
2504 	if (t && (!is_power_of_2(t) || t > 0x40000000))
2505 		return -EINVAL;
2506 
2507 	sbi->s_inode_readahead_blks = t;
2508 	return count;
2509 }
2510 
2511 static ssize_t sbi_ui_show(struct ext4_attr *a,
2512 			   struct ext4_sb_info *sbi, char *buf)
2513 {
2514 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2515 
2516 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2517 }
2518 
2519 static ssize_t sbi_ui_store(struct ext4_attr *a,
2520 			    struct ext4_sb_info *sbi,
2521 			    const char *buf, size_t count)
2522 {
2523 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2524 	unsigned long t;
2525 	int ret;
2526 
2527 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2528 	if (ret)
2529 		return ret;
2530 	*ui = t;
2531 	return count;
2532 }
2533 
2534 static ssize_t es_ui_show(struct ext4_attr *a,
2535 			   struct ext4_sb_info *sbi, char *buf)
2536 {
2537 
2538 	unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
2539 			   a->u.offset);
2540 
2541 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2542 }
2543 
2544 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2545 				  struct ext4_sb_info *sbi, char *buf)
2546 {
2547 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2548 		(unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2549 }
2550 
2551 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2552 				   struct ext4_sb_info *sbi,
2553 				   const char *buf, size_t count)
2554 {
2555 	unsigned long long val;
2556 	int ret;
2557 
2558 	if (parse_strtoull(buf, -1ULL, &val))
2559 		return -EINVAL;
2560 	ret = ext4_reserve_clusters(sbi, val);
2561 
2562 	return ret ? ret : count;
2563 }
2564 
2565 static ssize_t trigger_test_error(struct ext4_attr *a,
2566 				  struct ext4_sb_info *sbi,
2567 				  const char *buf, size_t count)
2568 {
2569 	int len = count;
2570 
2571 	if (!capable(CAP_SYS_ADMIN))
2572 		return -EPERM;
2573 
2574 	if (len && buf[len-1] == '\n')
2575 		len--;
2576 
2577 	if (len)
2578 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2579 	return count;
2580 }
2581 
2582 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2583 				   struct ext4_sb_info *sbi, char *buf)
2584 {
2585 	return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2586 }
2587 
2588 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2589 static struct ext4_attr ext4_attr_##_name = {			\
2590 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2591 	.show	= _show,					\
2592 	.store	= _store,					\
2593 	.u = {							\
2594 		.offset = offsetof(struct ext4_sb_info, _elname),\
2595 	},							\
2596 }
2597 
2598 #define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)		\
2599 static struct ext4_attr ext4_attr_##_name = {				\
2600 	.attr = {.name = __stringify(_name), .mode = _mode },		\
2601 	.show	= _show,						\
2602 	.store	= _store,						\
2603 	.u = {								\
2604 		.offset = offsetof(struct ext4_super_block, _elname),	\
2605 	},								\
2606 }
2607 
2608 #define EXT4_ATTR(name, mode, show, store) \
2609 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2610 
2611 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2612 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2613 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2614 
2615 #define EXT4_RO_ATTR_ES_UI(name, elname)	\
2616 	EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
2617 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2618 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2619 
2620 #define ATTR_LIST(name) &ext4_attr_##name.attr
2621 #define EXT4_DEPRECATED_ATTR(_name, _val)	\
2622 static struct ext4_attr ext4_attr_##_name = {			\
2623 	.attr = {.name = __stringify(_name), .mode = 0444 },	\
2624 	.show	= sbi_deprecated_show,				\
2625 	.u = {							\
2626 		.deprecated_val = _val,				\
2627 	},							\
2628 }
2629 
2630 EXT4_RO_ATTR(delayed_allocation_blocks);
2631 EXT4_RO_ATTR(session_write_kbytes);
2632 EXT4_RO_ATTR(lifetime_write_kbytes);
2633 EXT4_RW_ATTR(reserved_clusters);
2634 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2635 		 inode_readahead_blks_store, s_inode_readahead_blks);
2636 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2637 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2638 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2639 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2640 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2641 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2642 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2643 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2644 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2645 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2646 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2647 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2648 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2649 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2650 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2651 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2652 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
2653 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
2654 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
2655 
2656 static struct attribute *ext4_attrs[] = {
2657 	ATTR_LIST(delayed_allocation_blocks),
2658 	ATTR_LIST(session_write_kbytes),
2659 	ATTR_LIST(lifetime_write_kbytes),
2660 	ATTR_LIST(reserved_clusters),
2661 	ATTR_LIST(inode_readahead_blks),
2662 	ATTR_LIST(inode_goal),
2663 	ATTR_LIST(mb_stats),
2664 	ATTR_LIST(mb_max_to_scan),
2665 	ATTR_LIST(mb_min_to_scan),
2666 	ATTR_LIST(mb_order2_req),
2667 	ATTR_LIST(mb_stream_req),
2668 	ATTR_LIST(mb_group_prealloc),
2669 	ATTR_LIST(max_writeback_mb_bump),
2670 	ATTR_LIST(extent_max_zeroout_kb),
2671 	ATTR_LIST(trigger_fs_error),
2672 	ATTR_LIST(err_ratelimit_interval_ms),
2673 	ATTR_LIST(err_ratelimit_burst),
2674 	ATTR_LIST(warning_ratelimit_interval_ms),
2675 	ATTR_LIST(warning_ratelimit_burst),
2676 	ATTR_LIST(msg_ratelimit_interval_ms),
2677 	ATTR_LIST(msg_ratelimit_burst),
2678 	ATTR_LIST(errors_count),
2679 	ATTR_LIST(first_error_time),
2680 	ATTR_LIST(last_error_time),
2681 	NULL,
2682 };
2683 
2684 /* Features this copy of ext4 supports */
2685 EXT4_INFO_ATTR(lazy_itable_init);
2686 EXT4_INFO_ATTR(batched_discard);
2687 EXT4_INFO_ATTR(meta_bg_resize);
2688 
2689 static struct attribute *ext4_feat_attrs[] = {
2690 	ATTR_LIST(lazy_itable_init),
2691 	ATTR_LIST(batched_discard),
2692 	ATTR_LIST(meta_bg_resize),
2693 	NULL,
2694 };
2695 
2696 static ssize_t ext4_attr_show(struct kobject *kobj,
2697 			      struct attribute *attr, char *buf)
2698 {
2699 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2700 						s_kobj);
2701 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2702 
2703 	return a->show ? a->show(a, sbi, buf) : 0;
2704 }
2705 
2706 static ssize_t ext4_attr_store(struct kobject *kobj,
2707 			       struct attribute *attr,
2708 			       const char *buf, size_t len)
2709 {
2710 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2711 						s_kobj);
2712 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2713 
2714 	return a->store ? a->store(a, sbi, buf, len) : 0;
2715 }
2716 
2717 static void ext4_sb_release(struct kobject *kobj)
2718 {
2719 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2720 						s_kobj);
2721 	complete(&sbi->s_kobj_unregister);
2722 }
2723 
2724 static const struct sysfs_ops ext4_attr_ops = {
2725 	.show	= ext4_attr_show,
2726 	.store	= ext4_attr_store,
2727 };
2728 
2729 static struct kobj_type ext4_ktype = {
2730 	.default_attrs	= ext4_attrs,
2731 	.sysfs_ops	= &ext4_attr_ops,
2732 	.release	= ext4_sb_release,
2733 };
2734 
2735 static void ext4_feat_release(struct kobject *kobj)
2736 {
2737 	complete(&ext4_feat->f_kobj_unregister);
2738 }
2739 
2740 static ssize_t ext4_feat_show(struct kobject *kobj,
2741 			      struct attribute *attr, char *buf)
2742 {
2743 	return snprintf(buf, PAGE_SIZE, "supported\n");
2744 }
2745 
2746 /*
2747  * We can not use ext4_attr_show/store because it relies on the kobject
2748  * being embedded in the ext4_sb_info structure which is definitely not
2749  * true in this case.
2750  */
2751 static const struct sysfs_ops ext4_feat_ops = {
2752 	.show	= ext4_feat_show,
2753 	.store	= NULL,
2754 };
2755 
2756 static struct kobj_type ext4_feat_ktype = {
2757 	.default_attrs	= ext4_feat_attrs,
2758 	.sysfs_ops	= &ext4_feat_ops,
2759 	.release	= ext4_feat_release,
2760 };
2761 
2762 /*
2763  * Check whether this filesystem can be mounted based on
2764  * the features present and the RDONLY/RDWR mount requested.
2765  * Returns 1 if this filesystem can be mounted as requested,
2766  * 0 if it cannot be.
2767  */
2768 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2769 {
2770 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2771 		ext4_msg(sb, KERN_ERR,
2772 			"Couldn't mount because of "
2773 			"unsupported optional features (%x)",
2774 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2775 			~EXT4_FEATURE_INCOMPAT_SUPP));
2776 		return 0;
2777 	}
2778 
2779 	if (readonly)
2780 		return 1;
2781 
2782 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_READONLY)) {
2783 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2784 		sb->s_flags |= MS_RDONLY;
2785 		return 1;
2786 	}
2787 
2788 	/* Check that feature set is OK for a read-write mount */
2789 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2790 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2791 			 "unsupported optional features (%x)",
2792 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2793 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2794 		return 0;
2795 	}
2796 	/*
2797 	 * Large file size enabled file system can only be mounted
2798 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2799 	 */
2800 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2801 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2802 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2803 				 "cannot be mounted RDWR without "
2804 				 "CONFIG_LBDAF");
2805 			return 0;
2806 		}
2807 	}
2808 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2809 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2810 		ext4_msg(sb, KERN_ERR,
2811 			 "Can't support bigalloc feature without "
2812 			 "extents feature\n");
2813 		return 0;
2814 	}
2815 
2816 #ifndef CONFIG_QUOTA
2817 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2818 	    !readonly) {
2819 		ext4_msg(sb, KERN_ERR,
2820 			 "Filesystem with quota feature cannot be mounted RDWR "
2821 			 "without CONFIG_QUOTA");
2822 		return 0;
2823 	}
2824 #endif  /* CONFIG_QUOTA */
2825 	return 1;
2826 }
2827 
2828 /*
2829  * This function is called once a day if we have errors logged
2830  * on the file system
2831  */
2832 static void print_daily_error_info(unsigned long arg)
2833 {
2834 	struct super_block *sb = (struct super_block *) arg;
2835 	struct ext4_sb_info *sbi;
2836 	struct ext4_super_block *es;
2837 
2838 	sbi = EXT4_SB(sb);
2839 	es = sbi->s_es;
2840 
2841 	if (es->s_error_count)
2842 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2843 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2844 			 le32_to_cpu(es->s_error_count));
2845 	if (es->s_first_error_time) {
2846 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2847 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2848 		       (int) sizeof(es->s_first_error_func),
2849 		       es->s_first_error_func,
2850 		       le32_to_cpu(es->s_first_error_line));
2851 		if (es->s_first_error_ino)
2852 			printk(": inode %u",
2853 			       le32_to_cpu(es->s_first_error_ino));
2854 		if (es->s_first_error_block)
2855 			printk(": block %llu", (unsigned long long)
2856 			       le64_to_cpu(es->s_first_error_block));
2857 		printk("\n");
2858 	}
2859 	if (es->s_last_error_time) {
2860 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2861 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2862 		       (int) sizeof(es->s_last_error_func),
2863 		       es->s_last_error_func,
2864 		       le32_to_cpu(es->s_last_error_line));
2865 		if (es->s_last_error_ino)
2866 			printk(": inode %u",
2867 			       le32_to_cpu(es->s_last_error_ino));
2868 		if (es->s_last_error_block)
2869 			printk(": block %llu", (unsigned long long)
2870 			       le64_to_cpu(es->s_last_error_block));
2871 		printk("\n");
2872 	}
2873 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2874 }
2875 
2876 /* Find next suitable group and run ext4_init_inode_table */
2877 static int ext4_run_li_request(struct ext4_li_request *elr)
2878 {
2879 	struct ext4_group_desc *gdp = NULL;
2880 	ext4_group_t group, ngroups;
2881 	struct super_block *sb;
2882 	unsigned long timeout = 0;
2883 	int ret = 0;
2884 
2885 	sb = elr->lr_super;
2886 	ngroups = EXT4_SB(sb)->s_groups_count;
2887 
2888 	sb_start_write(sb);
2889 	for (group = elr->lr_next_group; group < ngroups; group++) {
2890 		gdp = ext4_get_group_desc(sb, group, NULL);
2891 		if (!gdp) {
2892 			ret = 1;
2893 			break;
2894 		}
2895 
2896 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2897 			break;
2898 	}
2899 
2900 	if (group >= ngroups)
2901 		ret = 1;
2902 
2903 	if (!ret) {
2904 		timeout = jiffies;
2905 		ret = ext4_init_inode_table(sb, group,
2906 					    elr->lr_timeout ? 0 : 1);
2907 		if (elr->lr_timeout == 0) {
2908 			timeout = (jiffies - timeout) *
2909 				  elr->lr_sbi->s_li_wait_mult;
2910 			elr->lr_timeout = timeout;
2911 		}
2912 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2913 		elr->lr_next_group = group + 1;
2914 	}
2915 	sb_end_write(sb);
2916 
2917 	return ret;
2918 }
2919 
2920 /*
2921  * Remove lr_request from the list_request and free the
2922  * request structure. Should be called with li_list_mtx held
2923  */
2924 static void ext4_remove_li_request(struct ext4_li_request *elr)
2925 {
2926 	struct ext4_sb_info *sbi;
2927 
2928 	if (!elr)
2929 		return;
2930 
2931 	sbi = elr->lr_sbi;
2932 
2933 	list_del(&elr->lr_request);
2934 	sbi->s_li_request = NULL;
2935 	kfree(elr);
2936 }
2937 
2938 static void ext4_unregister_li_request(struct super_block *sb)
2939 {
2940 	mutex_lock(&ext4_li_mtx);
2941 	if (!ext4_li_info) {
2942 		mutex_unlock(&ext4_li_mtx);
2943 		return;
2944 	}
2945 
2946 	mutex_lock(&ext4_li_info->li_list_mtx);
2947 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2948 	mutex_unlock(&ext4_li_info->li_list_mtx);
2949 	mutex_unlock(&ext4_li_mtx);
2950 }
2951 
2952 static struct task_struct *ext4_lazyinit_task;
2953 
2954 /*
2955  * This is the function where ext4lazyinit thread lives. It walks
2956  * through the request list searching for next scheduled filesystem.
2957  * When such a fs is found, run the lazy initialization request
2958  * (ext4_rn_li_request) and keep track of the time spend in this
2959  * function. Based on that time we compute next schedule time of
2960  * the request. When walking through the list is complete, compute
2961  * next waking time and put itself into sleep.
2962  */
2963 static int ext4_lazyinit_thread(void *arg)
2964 {
2965 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2966 	struct list_head *pos, *n;
2967 	struct ext4_li_request *elr;
2968 	unsigned long next_wakeup, cur;
2969 
2970 	BUG_ON(NULL == eli);
2971 
2972 cont_thread:
2973 	while (true) {
2974 		next_wakeup = MAX_JIFFY_OFFSET;
2975 
2976 		mutex_lock(&eli->li_list_mtx);
2977 		if (list_empty(&eli->li_request_list)) {
2978 			mutex_unlock(&eli->li_list_mtx);
2979 			goto exit_thread;
2980 		}
2981 
2982 		list_for_each_safe(pos, n, &eli->li_request_list) {
2983 			elr = list_entry(pos, struct ext4_li_request,
2984 					 lr_request);
2985 
2986 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2987 				if (ext4_run_li_request(elr) != 0) {
2988 					/* error, remove the lazy_init job */
2989 					ext4_remove_li_request(elr);
2990 					continue;
2991 				}
2992 			}
2993 
2994 			if (time_before(elr->lr_next_sched, next_wakeup))
2995 				next_wakeup = elr->lr_next_sched;
2996 		}
2997 		mutex_unlock(&eli->li_list_mtx);
2998 
2999 		try_to_freeze();
3000 
3001 		cur = jiffies;
3002 		if ((time_after_eq(cur, next_wakeup)) ||
3003 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3004 			cond_resched();
3005 			continue;
3006 		}
3007 
3008 		schedule_timeout_interruptible(next_wakeup - cur);
3009 
3010 		if (kthread_should_stop()) {
3011 			ext4_clear_request_list();
3012 			goto exit_thread;
3013 		}
3014 	}
3015 
3016 exit_thread:
3017 	/*
3018 	 * It looks like the request list is empty, but we need
3019 	 * to check it under the li_list_mtx lock, to prevent any
3020 	 * additions into it, and of course we should lock ext4_li_mtx
3021 	 * to atomically free the list and ext4_li_info, because at
3022 	 * this point another ext4 filesystem could be registering
3023 	 * new one.
3024 	 */
3025 	mutex_lock(&ext4_li_mtx);
3026 	mutex_lock(&eli->li_list_mtx);
3027 	if (!list_empty(&eli->li_request_list)) {
3028 		mutex_unlock(&eli->li_list_mtx);
3029 		mutex_unlock(&ext4_li_mtx);
3030 		goto cont_thread;
3031 	}
3032 	mutex_unlock(&eli->li_list_mtx);
3033 	kfree(ext4_li_info);
3034 	ext4_li_info = NULL;
3035 	mutex_unlock(&ext4_li_mtx);
3036 
3037 	return 0;
3038 }
3039 
3040 static void ext4_clear_request_list(void)
3041 {
3042 	struct list_head *pos, *n;
3043 	struct ext4_li_request *elr;
3044 
3045 	mutex_lock(&ext4_li_info->li_list_mtx);
3046 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3047 		elr = list_entry(pos, struct ext4_li_request,
3048 				 lr_request);
3049 		ext4_remove_li_request(elr);
3050 	}
3051 	mutex_unlock(&ext4_li_info->li_list_mtx);
3052 }
3053 
3054 static int ext4_run_lazyinit_thread(void)
3055 {
3056 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3057 					 ext4_li_info, "ext4lazyinit");
3058 	if (IS_ERR(ext4_lazyinit_task)) {
3059 		int err = PTR_ERR(ext4_lazyinit_task);
3060 		ext4_clear_request_list();
3061 		kfree(ext4_li_info);
3062 		ext4_li_info = NULL;
3063 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3064 				 "initialization thread\n",
3065 				 err);
3066 		return err;
3067 	}
3068 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3069 	return 0;
3070 }
3071 
3072 /*
3073  * Check whether it make sense to run itable init. thread or not.
3074  * If there is at least one uninitialized inode table, return
3075  * corresponding group number, else the loop goes through all
3076  * groups and return total number of groups.
3077  */
3078 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3079 {
3080 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3081 	struct ext4_group_desc *gdp = NULL;
3082 
3083 	for (group = 0; group < ngroups; group++) {
3084 		gdp = ext4_get_group_desc(sb, group, NULL);
3085 		if (!gdp)
3086 			continue;
3087 
3088 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3089 			break;
3090 	}
3091 
3092 	return group;
3093 }
3094 
3095 static int ext4_li_info_new(void)
3096 {
3097 	struct ext4_lazy_init *eli = NULL;
3098 
3099 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3100 	if (!eli)
3101 		return -ENOMEM;
3102 
3103 	INIT_LIST_HEAD(&eli->li_request_list);
3104 	mutex_init(&eli->li_list_mtx);
3105 
3106 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3107 
3108 	ext4_li_info = eli;
3109 
3110 	return 0;
3111 }
3112 
3113 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3114 					    ext4_group_t start)
3115 {
3116 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3117 	struct ext4_li_request *elr;
3118 
3119 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3120 	if (!elr)
3121 		return NULL;
3122 
3123 	elr->lr_super = sb;
3124 	elr->lr_sbi = sbi;
3125 	elr->lr_next_group = start;
3126 
3127 	/*
3128 	 * Randomize first schedule time of the request to
3129 	 * spread the inode table initialization requests
3130 	 * better.
3131 	 */
3132 	elr->lr_next_sched = jiffies + (prandom_u32() %
3133 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3134 	return elr;
3135 }
3136 
3137 int ext4_register_li_request(struct super_block *sb,
3138 			     ext4_group_t first_not_zeroed)
3139 {
3140 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3141 	struct ext4_li_request *elr = NULL;
3142 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3143 	int ret = 0;
3144 
3145 	mutex_lock(&ext4_li_mtx);
3146 	if (sbi->s_li_request != NULL) {
3147 		/*
3148 		 * Reset timeout so it can be computed again, because
3149 		 * s_li_wait_mult might have changed.
3150 		 */
3151 		sbi->s_li_request->lr_timeout = 0;
3152 		goto out;
3153 	}
3154 
3155 	if (first_not_zeroed == ngroups ||
3156 	    (sb->s_flags & MS_RDONLY) ||
3157 	    !test_opt(sb, INIT_INODE_TABLE))
3158 		goto out;
3159 
3160 	elr = ext4_li_request_new(sb, first_not_zeroed);
3161 	if (!elr) {
3162 		ret = -ENOMEM;
3163 		goto out;
3164 	}
3165 
3166 	if (NULL == ext4_li_info) {
3167 		ret = ext4_li_info_new();
3168 		if (ret)
3169 			goto out;
3170 	}
3171 
3172 	mutex_lock(&ext4_li_info->li_list_mtx);
3173 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3174 	mutex_unlock(&ext4_li_info->li_list_mtx);
3175 
3176 	sbi->s_li_request = elr;
3177 	/*
3178 	 * set elr to NULL here since it has been inserted to
3179 	 * the request_list and the removal and free of it is
3180 	 * handled by ext4_clear_request_list from now on.
3181 	 */
3182 	elr = NULL;
3183 
3184 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3185 		ret = ext4_run_lazyinit_thread();
3186 		if (ret)
3187 			goto out;
3188 	}
3189 out:
3190 	mutex_unlock(&ext4_li_mtx);
3191 	if (ret)
3192 		kfree(elr);
3193 	return ret;
3194 }
3195 
3196 /*
3197  * We do not need to lock anything since this is called on
3198  * module unload.
3199  */
3200 static void ext4_destroy_lazyinit_thread(void)
3201 {
3202 	/*
3203 	 * If thread exited earlier
3204 	 * there's nothing to be done.
3205 	 */
3206 	if (!ext4_li_info || !ext4_lazyinit_task)
3207 		return;
3208 
3209 	kthread_stop(ext4_lazyinit_task);
3210 }
3211 
3212 static int set_journal_csum_feature_set(struct super_block *sb)
3213 {
3214 	int ret = 1;
3215 	int compat, incompat;
3216 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3217 
3218 	if (ext4_has_metadata_csum(sb)) {
3219 		/* journal checksum v3 */
3220 		compat = 0;
3221 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3222 	} else {
3223 		/* journal checksum v1 */
3224 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3225 		incompat = 0;
3226 	}
3227 
3228 	jbd2_journal_clear_features(sbi->s_journal,
3229 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3230 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3231 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3232 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3233 		ret = jbd2_journal_set_features(sbi->s_journal,
3234 				compat, 0,
3235 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3236 				incompat);
3237 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3238 		ret = jbd2_journal_set_features(sbi->s_journal,
3239 				compat, 0,
3240 				incompat);
3241 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3242 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3243 	} else {
3244 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3245 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3246 	}
3247 
3248 	return ret;
3249 }
3250 
3251 /*
3252  * Note: calculating the overhead so we can be compatible with
3253  * historical BSD practice is quite difficult in the face of
3254  * clusters/bigalloc.  This is because multiple metadata blocks from
3255  * different block group can end up in the same allocation cluster.
3256  * Calculating the exact overhead in the face of clustered allocation
3257  * requires either O(all block bitmaps) in memory or O(number of block
3258  * groups**2) in time.  We will still calculate the superblock for
3259  * older file systems --- and if we come across with a bigalloc file
3260  * system with zero in s_overhead_clusters the estimate will be close to
3261  * correct especially for very large cluster sizes --- but for newer
3262  * file systems, it's better to calculate this figure once at mkfs
3263  * time, and store it in the superblock.  If the superblock value is
3264  * present (even for non-bigalloc file systems), we will use it.
3265  */
3266 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3267 			  char *buf)
3268 {
3269 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3270 	struct ext4_group_desc	*gdp;
3271 	ext4_fsblk_t		first_block, last_block, b;
3272 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3273 	int			s, j, count = 0;
3274 
3275 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3276 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3277 			sbi->s_itb_per_group + 2);
3278 
3279 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3280 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3281 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3282 	for (i = 0; i < ngroups; i++) {
3283 		gdp = ext4_get_group_desc(sb, i, NULL);
3284 		b = ext4_block_bitmap(sb, gdp);
3285 		if (b >= first_block && b <= last_block) {
3286 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3287 			count++;
3288 		}
3289 		b = ext4_inode_bitmap(sb, gdp);
3290 		if (b >= first_block && b <= last_block) {
3291 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3292 			count++;
3293 		}
3294 		b = ext4_inode_table(sb, gdp);
3295 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3296 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3297 				int c = EXT4_B2C(sbi, b - first_block);
3298 				ext4_set_bit(c, buf);
3299 				count++;
3300 			}
3301 		if (i != grp)
3302 			continue;
3303 		s = 0;
3304 		if (ext4_bg_has_super(sb, grp)) {
3305 			ext4_set_bit(s++, buf);
3306 			count++;
3307 		}
3308 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3309 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3310 			count++;
3311 		}
3312 	}
3313 	if (!count)
3314 		return 0;
3315 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3316 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3317 }
3318 
3319 /*
3320  * Compute the overhead and stash it in sbi->s_overhead
3321  */
3322 int ext4_calculate_overhead(struct super_block *sb)
3323 {
3324 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3325 	struct ext4_super_block *es = sbi->s_es;
3326 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3327 	ext4_fsblk_t overhead = 0;
3328 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3329 
3330 	if (!buf)
3331 		return -ENOMEM;
3332 
3333 	/*
3334 	 * Compute the overhead (FS structures).  This is constant
3335 	 * for a given filesystem unless the number of block groups
3336 	 * changes so we cache the previous value until it does.
3337 	 */
3338 
3339 	/*
3340 	 * All of the blocks before first_data_block are overhead
3341 	 */
3342 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3343 
3344 	/*
3345 	 * Add the overhead found in each block group
3346 	 */
3347 	for (i = 0; i < ngroups; i++) {
3348 		int blks;
3349 
3350 		blks = count_overhead(sb, i, buf);
3351 		overhead += blks;
3352 		if (blks)
3353 			memset(buf, 0, PAGE_SIZE);
3354 		cond_resched();
3355 	}
3356 	/* Add the internal journal blocks as well */
3357 	if (sbi->s_journal && !sbi->journal_bdev)
3358 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3359 
3360 	sbi->s_overhead = overhead;
3361 	smp_wmb();
3362 	free_page((unsigned long) buf);
3363 	return 0;
3364 }
3365 
3366 
3367 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3368 {
3369 	ext4_fsblk_t resv_clusters;
3370 
3371 	/*
3372 	 * There's no need to reserve anything when we aren't using extents.
3373 	 * The space estimates are exact, there are no unwritten extents,
3374 	 * hole punching doesn't need new metadata... This is needed especially
3375 	 * to keep ext2/3 backward compatibility.
3376 	 */
3377 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3378 		return 0;
3379 	/*
3380 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3381 	 * This should cover the situations where we can not afford to run
3382 	 * out of space like for example punch hole, or converting
3383 	 * unwritten extents in delalloc path. In most cases such
3384 	 * allocation would require 1, or 2 blocks, higher numbers are
3385 	 * very rare.
3386 	 */
3387 	resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3388 			EXT4_SB(sb)->s_cluster_bits;
3389 
3390 	do_div(resv_clusters, 50);
3391 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3392 
3393 	return resv_clusters;
3394 }
3395 
3396 
3397 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3398 {
3399 	ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3400 				sbi->s_cluster_bits;
3401 
3402 	if (count >= clusters)
3403 		return -EINVAL;
3404 
3405 	atomic64_set(&sbi->s_resv_clusters, count);
3406 	return 0;
3407 }
3408 
3409 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3410 {
3411 	char *orig_data = kstrdup(data, GFP_KERNEL);
3412 	struct buffer_head *bh;
3413 	struct ext4_super_block *es = NULL;
3414 	struct ext4_sb_info *sbi;
3415 	ext4_fsblk_t block;
3416 	ext4_fsblk_t sb_block = get_sb_block(&data);
3417 	ext4_fsblk_t logical_sb_block;
3418 	unsigned long offset = 0;
3419 	unsigned long journal_devnum = 0;
3420 	unsigned long def_mount_opts;
3421 	struct inode *root;
3422 	char *cp;
3423 	const char *descr;
3424 	int ret = -ENOMEM;
3425 	int blocksize, clustersize;
3426 	unsigned int db_count;
3427 	unsigned int i;
3428 	int needs_recovery, has_huge_files, has_bigalloc;
3429 	__u64 blocks_count;
3430 	int err = 0;
3431 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3432 	ext4_group_t first_not_zeroed;
3433 
3434 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3435 	if (!sbi)
3436 		goto out_free_orig;
3437 
3438 	sbi->s_blockgroup_lock =
3439 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3440 	if (!sbi->s_blockgroup_lock) {
3441 		kfree(sbi);
3442 		goto out_free_orig;
3443 	}
3444 	sb->s_fs_info = sbi;
3445 	sbi->s_sb = sb;
3446 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3447 	sbi->s_sb_block = sb_block;
3448 	if (sb->s_bdev->bd_part)
3449 		sbi->s_sectors_written_start =
3450 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3451 
3452 	/* Cleanup superblock name */
3453 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3454 		*cp = '!';
3455 
3456 	/* -EINVAL is default */
3457 	ret = -EINVAL;
3458 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3459 	if (!blocksize) {
3460 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3461 		goto out_fail;
3462 	}
3463 
3464 	/*
3465 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3466 	 * block sizes.  We need to calculate the offset from buffer start.
3467 	 */
3468 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3469 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3470 		offset = do_div(logical_sb_block, blocksize);
3471 	} else {
3472 		logical_sb_block = sb_block;
3473 	}
3474 
3475 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3476 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3477 		goto out_fail;
3478 	}
3479 	/*
3480 	 * Note: s_es must be initialized as soon as possible because
3481 	 *       some ext4 macro-instructions depend on its value
3482 	 */
3483 	es = (struct ext4_super_block *) (bh->b_data + offset);
3484 	sbi->s_es = es;
3485 	sb->s_magic = le16_to_cpu(es->s_magic);
3486 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3487 		goto cantfind_ext4;
3488 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3489 
3490 	/* Warn if metadata_csum and gdt_csum are both set. */
3491 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3492 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3493 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3494 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3495 			     "redundant flags; please run fsck.");
3496 
3497 	/* Check for a known checksum algorithm */
3498 	if (!ext4_verify_csum_type(sb, es)) {
3499 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3500 			 "unknown checksum algorithm.");
3501 		silent = 1;
3502 		goto cantfind_ext4;
3503 	}
3504 
3505 	/* Load the checksum driver */
3506 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3507 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3508 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3509 		if (IS_ERR(sbi->s_chksum_driver)) {
3510 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3511 			ret = PTR_ERR(sbi->s_chksum_driver);
3512 			sbi->s_chksum_driver = NULL;
3513 			goto failed_mount;
3514 		}
3515 	}
3516 
3517 	/* Check superblock checksum */
3518 	if (!ext4_superblock_csum_verify(sb, es)) {
3519 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3520 			 "invalid superblock checksum.  Run e2fsck?");
3521 		silent = 1;
3522 		goto cantfind_ext4;
3523 	}
3524 
3525 	/* Precompute checksum seed for all metadata */
3526 	if (ext4_has_metadata_csum(sb))
3527 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3528 					       sizeof(es->s_uuid));
3529 
3530 	/* Set defaults before we parse the mount options */
3531 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3532 	set_opt(sb, INIT_INODE_TABLE);
3533 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3534 		set_opt(sb, DEBUG);
3535 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3536 		set_opt(sb, GRPID);
3537 	if (def_mount_opts & EXT4_DEFM_UID16)
3538 		set_opt(sb, NO_UID32);
3539 	/* xattr user namespace & acls are now defaulted on */
3540 	set_opt(sb, XATTR_USER);
3541 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3542 	set_opt(sb, POSIX_ACL);
3543 #endif
3544 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3545 	if (ext4_has_metadata_csum(sb))
3546 		set_opt(sb, JOURNAL_CHECKSUM);
3547 
3548 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3549 		set_opt(sb, JOURNAL_DATA);
3550 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3551 		set_opt(sb, ORDERED_DATA);
3552 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3553 		set_opt(sb, WRITEBACK_DATA);
3554 
3555 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3556 		set_opt(sb, ERRORS_PANIC);
3557 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3558 		set_opt(sb, ERRORS_CONT);
3559 	else
3560 		set_opt(sb, ERRORS_RO);
3561 	/* block_validity enabled by default; disable with noblock_validity */
3562 	set_opt(sb, BLOCK_VALIDITY);
3563 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3564 		set_opt(sb, DISCARD);
3565 
3566 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3567 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3568 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3569 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3570 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3571 
3572 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3573 		set_opt(sb, BARRIER);
3574 
3575 	/*
3576 	 * enable delayed allocation by default
3577 	 * Use -o nodelalloc to turn it off
3578 	 */
3579 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3580 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3581 		set_opt(sb, DELALLOC);
3582 
3583 	/*
3584 	 * set default s_li_wait_mult for lazyinit, for the case there is
3585 	 * no mount option specified.
3586 	 */
3587 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3588 
3589 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3590 			   &journal_devnum, &journal_ioprio, 0)) {
3591 		ext4_msg(sb, KERN_WARNING,
3592 			 "failed to parse options in superblock: %s",
3593 			 sbi->s_es->s_mount_opts);
3594 	}
3595 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3596 	if (!parse_options((char *) data, sb, &journal_devnum,
3597 			   &journal_ioprio, 0))
3598 		goto failed_mount;
3599 
3600 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3601 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3602 			    "with data=journal disables delayed "
3603 			    "allocation and O_DIRECT support!\n");
3604 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3605 			ext4_msg(sb, KERN_ERR, "can't mount with "
3606 				 "both data=journal and delalloc");
3607 			goto failed_mount;
3608 		}
3609 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3610 			ext4_msg(sb, KERN_ERR, "can't mount with "
3611 				 "both data=journal and dioread_nolock");
3612 			goto failed_mount;
3613 		}
3614 		if (test_opt(sb, DAX)) {
3615 			ext4_msg(sb, KERN_ERR, "can't mount with "
3616 				 "both data=journal and dax");
3617 			goto failed_mount;
3618 		}
3619 		if (test_opt(sb, DELALLOC))
3620 			clear_opt(sb, DELALLOC);
3621 	}
3622 
3623 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3624 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3625 
3626 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3627 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3628 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3629 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3630 		ext4_msg(sb, KERN_WARNING,
3631 		       "feature flags set on rev 0 fs, "
3632 		       "running e2fsck is recommended");
3633 
3634 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3635 		set_opt2(sb, HURD_COMPAT);
3636 		if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3637 					      EXT4_FEATURE_INCOMPAT_64BIT)) {
3638 			ext4_msg(sb, KERN_ERR,
3639 				 "The Hurd can't support 64-bit file systems");
3640 			goto failed_mount;
3641 		}
3642 	}
3643 
3644 	if (IS_EXT2_SB(sb)) {
3645 		if (ext2_feature_set_ok(sb))
3646 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3647 				 "using the ext4 subsystem");
3648 		else {
3649 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3650 				 "to feature incompatibilities");
3651 			goto failed_mount;
3652 		}
3653 	}
3654 
3655 	if (IS_EXT3_SB(sb)) {
3656 		if (ext3_feature_set_ok(sb))
3657 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3658 				 "using the ext4 subsystem");
3659 		else {
3660 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3661 				 "to feature incompatibilities");
3662 			goto failed_mount;
3663 		}
3664 	}
3665 
3666 	/*
3667 	 * Check feature flags regardless of the revision level, since we
3668 	 * previously didn't change the revision level when setting the flags,
3669 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3670 	 */
3671 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3672 		goto failed_mount;
3673 
3674 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3675 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3676 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3677 		ext4_msg(sb, KERN_ERR,
3678 		       "Unsupported filesystem blocksize %d", blocksize);
3679 		goto failed_mount;
3680 	}
3681 
3682 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3683 		if (blocksize != PAGE_SIZE) {
3684 			ext4_msg(sb, KERN_ERR,
3685 					"error: unsupported blocksize for dax");
3686 			goto failed_mount;
3687 		}
3688 		if (!sb->s_bdev->bd_disk->fops->direct_access) {
3689 			ext4_msg(sb, KERN_ERR,
3690 					"error: device does not support dax");
3691 			goto failed_mount;
3692 		}
3693 	}
3694 
3695 	if (sb->s_blocksize != blocksize) {
3696 		/* Validate the filesystem blocksize */
3697 		if (!sb_set_blocksize(sb, blocksize)) {
3698 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3699 					blocksize);
3700 			goto failed_mount;
3701 		}
3702 
3703 		brelse(bh);
3704 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3705 		offset = do_div(logical_sb_block, blocksize);
3706 		bh = sb_bread_unmovable(sb, logical_sb_block);
3707 		if (!bh) {
3708 			ext4_msg(sb, KERN_ERR,
3709 			       "Can't read superblock on 2nd try");
3710 			goto failed_mount;
3711 		}
3712 		es = (struct ext4_super_block *)(bh->b_data + offset);
3713 		sbi->s_es = es;
3714 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3715 			ext4_msg(sb, KERN_ERR,
3716 			       "Magic mismatch, very weird!");
3717 			goto failed_mount;
3718 		}
3719 	}
3720 
3721 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3722 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3723 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3724 						      has_huge_files);
3725 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3726 
3727 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3728 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3729 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3730 	} else {
3731 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3732 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3733 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3734 		    (!is_power_of_2(sbi->s_inode_size)) ||
3735 		    (sbi->s_inode_size > blocksize)) {
3736 			ext4_msg(sb, KERN_ERR,
3737 			       "unsupported inode size: %d",
3738 			       sbi->s_inode_size);
3739 			goto failed_mount;
3740 		}
3741 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3742 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3743 	}
3744 
3745 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3746 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3747 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3748 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3749 		    !is_power_of_2(sbi->s_desc_size)) {
3750 			ext4_msg(sb, KERN_ERR,
3751 			       "unsupported descriptor size %lu",
3752 			       sbi->s_desc_size);
3753 			goto failed_mount;
3754 		}
3755 	} else
3756 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3757 
3758 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3759 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3760 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3761 		goto cantfind_ext4;
3762 
3763 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3764 	if (sbi->s_inodes_per_block == 0)
3765 		goto cantfind_ext4;
3766 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3767 					sbi->s_inodes_per_block;
3768 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3769 	sbi->s_sbh = bh;
3770 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3771 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3772 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3773 
3774 	for (i = 0; i < 4; i++)
3775 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3776 	sbi->s_def_hash_version = es->s_def_hash_version;
3777 	if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3778 		i = le32_to_cpu(es->s_flags);
3779 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3780 			sbi->s_hash_unsigned = 3;
3781 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3782 #ifdef __CHAR_UNSIGNED__
3783 			if (!(sb->s_flags & MS_RDONLY))
3784 				es->s_flags |=
3785 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3786 			sbi->s_hash_unsigned = 3;
3787 #else
3788 			if (!(sb->s_flags & MS_RDONLY))
3789 				es->s_flags |=
3790 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3791 #endif
3792 		}
3793 	}
3794 
3795 	/* Handle clustersize */
3796 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3797 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3798 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3799 	if (has_bigalloc) {
3800 		if (clustersize < blocksize) {
3801 			ext4_msg(sb, KERN_ERR,
3802 				 "cluster size (%d) smaller than "
3803 				 "block size (%d)", clustersize, blocksize);
3804 			goto failed_mount;
3805 		}
3806 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3807 			le32_to_cpu(es->s_log_block_size);
3808 		sbi->s_clusters_per_group =
3809 			le32_to_cpu(es->s_clusters_per_group);
3810 		if (sbi->s_clusters_per_group > blocksize * 8) {
3811 			ext4_msg(sb, KERN_ERR,
3812 				 "#clusters per group too big: %lu",
3813 				 sbi->s_clusters_per_group);
3814 			goto failed_mount;
3815 		}
3816 		if (sbi->s_blocks_per_group !=
3817 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3818 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3819 				 "clusters per group (%lu) inconsistent",
3820 				 sbi->s_blocks_per_group,
3821 				 sbi->s_clusters_per_group);
3822 			goto failed_mount;
3823 		}
3824 	} else {
3825 		if (clustersize != blocksize) {
3826 			ext4_warning(sb, "fragment/cluster size (%d) != "
3827 				     "block size (%d)", clustersize,
3828 				     blocksize);
3829 			clustersize = blocksize;
3830 		}
3831 		if (sbi->s_blocks_per_group > blocksize * 8) {
3832 			ext4_msg(sb, KERN_ERR,
3833 				 "#blocks per group too big: %lu",
3834 				 sbi->s_blocks_per_group);
3835 			goto failed_mount;
3836 		}
3837 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3838 		sbi->s_cluster_bits = 0;
3839 	}
3840 	sbi->s_cluster_ratio = clustersize / blocksize;
3841 
3842 	if (sbi->s_inodes_per_group > blocksize * 8) {
3843 		ext4_msg(sb, KERN_ERR,
3844 		       "#inodes per group too big: %lu",
3845 		       sbi->s_inodes_per_group);
3846 		goto failed_mount;
3847 	}
3848 
3849 	/* Do we have standard group size of clustersize * 8 blocks ? */
3850 	if (sbi->s_blocks_per_group == clustersize << 3)
3851 		set_opt2(sb, STD_GROUP_SIZE);
3852 
3853 	/*
3854 	 * Test whether we have more sectors than will fit in sector_t,
3855 	 * and whether the max offset is addressable by the page cache.
3856 	 */
3857 	err = generic_check_addressable(sb->s_blocksize_bits,
3858 					ext4_blocks_count(es));
3859 	if (err) {
3860 		ext4_msg(sb, KERN_ERR, "filesystem"
3861 			 " too large to mount safely on this system");
3862 		if (sizeof(sector_t) < 8)
3863 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3864 		goto failed_mount;
3865 	}
3866 
3867 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3868 		goto cantfind_ext4;
3869 
3870 	/* check blocks count against device size */
3871 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3872 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3873 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3874 		       "exceeds size of device (%llu blocks)",
3875 		       ext4_blocks_count(es), blocks_count);
3876 		goto failed_mount;
3877 	}
3878 
3879 	/*
3880 	 * It makes no sense for the first data block to be beyond the end
3881 	 * of the filesystem.
3882 	 */
3883 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3884 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3885 			 "block %u is beyond end of filesystem (%llu)",
3886 			 le32_to_cpu(es->s_first_data_block),
3887 			 ext4_blocks_count(es));
3888 		goto failed_mount;
3889 	}
3890 	blocks_count = (ext4_blocks_count(es) -
3891 			le32_to_cpu(es->s_first_data_block) +
3892 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3893 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3894 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3895 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3896 		       "(block count %llu, first data block %u, "
3897 		       "blocks per group %lu)", sbi->s_groups_count,
3898 		       ext4_blocks_count(es),
3899 		       le32_to_cpu(es->s_first_data_block),
3900 		       EXT4_BLOCKS_PER_GROUP(sb));
3901 		goto failed_mount;
3902 	}
3903 	sbi->s_groups_count = blocks_count;
3904 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3905 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3906 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3907 		   EXT4_DESC_PER_BLOCK(sb);
3908 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3909 					  sizeof(struct buffer_head *),
3910 					  GFP_KERNEL);
3911 	if (sbi->s_group_desc == NULL) {
3912 		ext4_msg(sb, KERN_ERR, "not enough memory");
3913 		ret = -ENOMEM;
3914 		goto failed_mount;
3915 	}
3916 
3917 	if (ext4_proc_root)
3918 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3919 
3920 	if (sbi->s_proc)
3921 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3922 				 &ext4_seq_options_fops, sb);
3923 
3924 	bgl_lock_init(sbi->s_blockgroup_lock);
3925 
3926 	for (i = 0; i < db_count; i++) {
3927 		block = descriptor_loc(sb, logical_sb_block, i);
3928 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3929 		if (!sbi->s_group_desc[i]) {
3930 			ext4_msg(sb, KERN_ERR,
3931 			       "can't read group descriptor %d", i);
3932 			db_count = i;
3933 			goto failed_mount2;
3934 		}
3935 	}
3936 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3937 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3938 		goto failed_mount2;
3939 	}
3940 
3941 	sbi->s_gdb_count = db_count;
3942 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3943 	spin_lock_init(&sbi->s_next_gen_lock);
3944 
3945 	setup_timer(&sbi->s_err_report, print_daily_error_info,
3946 		(unsigned long) sb);
3947 
3948 	/* Register extent status tree shrinker */
3949 	if (ext4_es_register_shrinker(sbi))
3950 		goto failed_mount3;
3951 
3952 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3953 	sbi->s_extent_max_zeroout_kb = 32;
3954 
3955 	/*
3956 	 * set up enough so that it can read an inode
3957 	 */
3958 	sb->s_op = &ext4_sops;
3959 	sb->s_export_op = &ext4_export_ops;
3960 	sb->s_xattr = ext4_xattr_handlers;
3961 #ifdef CONFIG_QUOTA
3962 	sb->dq_op = &ext4_quota_operations;
3963 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3964 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
3965 	else
3966 		sb->s_qcop = &ext4_qctl_operations;
3967 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
3968 #endif
3969 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3970 
3971 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3972 	mutex_init(&sbi->s_orphan_lock);
3973 
3974 	sb->s_root = NULL;
3975 
3976 	needs_recovery = (es->s_last_orphan != 0 ||
3977 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3978 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3979 
3980 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3981 	    !(sb->s_flags & MS_RDONLY))
3982 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3983 			goto failed_mount3a;
3984 
3985 	/*
3986 	 * The first inode we look at is the journal inode.  Don't try
3987 	 * root first: it may be modified in the journal!
3988 	 */
3989 	if (!test_opt(sb, NOLOAD) &&
3990 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3991 		if (ext4_load_journal(sb, es, journal_devnum))
3992 			goto failed_mount3a;
3993 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3994 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3995 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3996 		       "suppressed and not mounted read-only");
3997 		goto failed_mount_wq;
3998 	} else {
3999 		clear_opt(sb, DATA_FLAGS);
4000 		sbi->s_journal = NULL;
4001 		needs_recovery = 0;
4002 		goto no_journal;
4003 	}
4004 
4005 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
4006 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4007 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4008 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4009 		goto failed_mount_wq;
4010 	}
4011 
4012 	if (!set_journal_csum_feature_set(sb)) {
4013 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4014 			 "feature set");
4015 		goto failed_mount_wq;
4016 	}
4017 
4018 	/* We have now updated the journal if required, so we can
4019 	 * validate the data journaling mode. */
4020 	switch (test_opt(sb, DATA_FLAGS)) {
4021 	case 0:
4022 		/* No mode set, assume a default based on the journal
4023 		 * capabilities: ORDERED_DATA if the journal can
4024 		 * cope, else JOURNAL_DATA
4025 		 */
4026 		if (jbd2_journal_check_available_features
4027 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4028 			set_opt(sb, ORDERED_DATA);
4029 		else
4030 			set_opt(sb, JOURNAL_DATA);
4031 		break;
4032 
4033 	case EXT4_MOUNT_ORDERED_DATA:
4034 	case EXT4_MOUNT_WRITEBACK_DATA:
4035 		if (!jbd2_journal_check_available_features
4036 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4037 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4038 			       "requested data journaling mode");
4039 			goto failed_mount_wq;
4040 		}
4041 	default:
4042 		break;
4043 	}
4044 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4045 
4046 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4047 
4048 no_journal:
4049 	if (ext4_mballoc_ready) {
4050 		sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4051 		if (!sbi->s_mb_cache) {
4052 			ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4053 			goto failed_mount_wq;
4054 		}
4055 	}
4056 
4057 	/*
4058 	 * Get the # of file system overhead blocks from the
4059 	 * superblock if present.
4060 	 */
4061 	if (es->s_overhead_clusters)
4062 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4063 	else {
4064 		err = ext4_calculate_overhead(sb);
4065 		if (err)
4066 			goto failed_mount_wq;
4067 	}
4068 
4069 	/*
4070 	 * The maximum number of concurrent works can be high and
4071 	 * concurrency isn't really necessary.  Limit it to 1.
4072 	 */
4073 	EXT4_SB(sb)->rsv_conversion_wq =
4074 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4075 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4076 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4077 		ret = -ENOMEM;
4078 		goto failed_mount4;
4079 	}
4080 
4081 	/*
4082 	 * The jbd2_journal_load will have done any necessary log recovery,
4083 	 * so we can safely mount the rest of the filesystem now.
4084 	 */
4085 
4086 	root = ext4_iget(sb, EXT4_ROOT_INO);
4087 	if (IS_ERR(root)) {
4088 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4089 		ret = PTR_ERR(root);
4090 		root = NULL;
4091 		goto failed_mount4;
4092 	}
4093 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4094 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4095 		iput(root);
4096 		goto failed_mount4;
4097 	}
4098 	sb->s_root = d_make_root(root);
4099 	if (!sb->s_root) {
4100 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4101 		ret = -ENOMEM;
4102 		goto failed_mount4;
4103 	}
4104 
4105 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4106 		sb->s_flags |= MS_RDONLY;
4107 
4108 	/* determine the minimum size of new large inodes, if present */
4109 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4110 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4111 						     EXT4_GOOD_OLD_INODE_SIZE;
4112 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4113 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4114 			if (sbi->s_want_extra_isize <
4115 			    le16_to_cpu(es->s_want_extra_isize))
4116 				sbi->s_want_extra_isize =
4117 					le16_to_cpu(es->s_want_extra_isize);
4118 			if (sbi->s_want_extra_isize <
4119 			    le16_to_cpu(es->s_min_extra_isize))
4120 				sbi->s_want_extra_isize =
4121 					le16_to_cpu(es->s_min_extra_isize);
4122 		}
4123 	}
4124 	/* Check if enough inode space is available */
4125 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4126 							sbi->s_inode_size) {
4127 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4128 						       EXT4_GOOD_OLD_INODE_SIZE;
4129 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4130 			 "available");
4131 	}
4132 
4133 	err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4134 	if (err) {
4135 		ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4136 			 "reserved pool", ext4_calculate_resv_clusters(sb));
4137 		goto failed_mount4a;
4138 	}
4139 
4140 	err = ext4_setup_system_zone(sb);
4141 	if (err) {
4142 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4143 			 "zone (%d)", err);
4144 		goto failed_mount4a;
4145 	}
4146 
4147 	ext4_ext_init(sb);
4148 	err = ext4_mb_init(sb);
4149 	if (err) {
4150 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4151 			 err);
4152 		goto failed_mount5;
4153 	}
4154 
4155 	block = ext4_count_free_clusters(sb);
4156 	ext4_free_blocks_count_set(sbi->s_es,
4157 				   EXT4_C2B(sbi, block));
4158 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4159 				  GFP_KERNEL);
4160 	if (!err) {
4161 		unsigned long freei = ext4_count_free_inodes(sb);
4162 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4163 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4164 					  GFP_KERNEL);
4165 	}
4166 	if (!err)
4167 		err = percpu_counter_init(&sbi->s_dirs_counter,
4168 					  ext4_count_dirs(sb), GFP_KERNEL);
4169 	if (!err)
4170 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4171 					  GFP_KERNEL);
4172 	if (err) {
4173 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4174 		goto failed_mount6;
4175 	}
4176 
4177 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
4178 		if (!ext4_fill_flex_info(sb)) {
4179 			ext4_msg(sb, KERN_ERR,
4180 			       "unable to initialize "
4181 			       "flex_bg meta info!");
4182 			goto failed_mount6;
4183 		}
4184 
4185 	err = ext4_register_li_request(sb, first_not_zeroed);
4186 	if (err)
4187 		goto failed_mount6;
4188 
4189 	sbi->s_kobj.kset = ext4_kset;
4190 	init_completion(&sbi->s_kobj_unregister);
4191 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4192 				   "%s", sb->s_id);
4193 	if (err)
4194 		goto failed_mount7;
4195 
4196 #ifdef CONFIG_QUOTA
4197 	/* Enable quota usage during mount. */
4198 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4199 	    !(sb->s_flags & MS_RDONLY)) {
4200 		err = ext4_enable_quotas(sb);
4201 		if (err)
4202 			goto failed_mount8;
4203 	}
4204 #endif  /* CONFIG_QUOTA */
4205 
4206 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4207 	ext4_orphan_cleanup(sb, es);
4208 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4209 	if (needs_recovery) {
4210 		ext4_msg(sb, KERN_INFO, "recovery complete");
4211 		ext4_mark_recovery_complete(sb, es);
4212 	}
4213 	if (EXT4_SB(sb)->s_journal) {
4214 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4215 			descr = " journalled data mode";
4216 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4217 			descr = " ordered data mode";
4218 		else
4219 			descr = " writeback data mode";
4220 	} else
4221 		descr = "out journal";
4222 
4223 	if (test_opt(sb, DISCARD)) {
4224 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4225 		if (!blk_queue_discard(q))
4226 			ext4_msg(sb, KERN_WARNING,
4227 				 "mounting with \"discard\" option, but "
4228 				 "the device does not support discard");
4229 	}
4230 
4231 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4232 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4233 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4234 
4235 	if (es->s_error_count)
4236 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4237 
4238 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4239 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4240 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4241 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4242 
4243 	kfree(orig_data);
4244 	return 0;
4245 
4246 cantfind_ext4:
4247 	if (!silent)
4248 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4249 	goto failed_mount;
4250 
4251 #ifdef CONFIG_QUOTA
4252 failed_mount8:
4253 	kobject_del(&sbi->s_kobj);
4254 #endif
4255 failed_mount7:
4256 	ext4_unregister_li_request(sb);
4257 failed_mount6:
4258 	ext4_mb_release(sb);
4259 	if (sbi->s_flex_groups)
4260 		kvfree(sbi->s_flex_groups);
4261 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4262 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4263 	percpu_counter_destroy(&sbi->s_dirs_counter);
4264 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4265 failed_mount5:
4266 	ext4_ext_release(sb);
4267 	ext4_release_system_zone(sb);
4268 failed_mount4a:
4269 	dput(sb->s_root);
4270 	sb->s_root = NULL;
4271 failed_mount4:
4272 	ext4_msg(sb, KERN_ERR, "mount failed");
4273 	if (EXT4_SB(sb)->rsv_conversion_wq)
4274 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4275 failed_mount_wq:
4276 	if (sbi->s_journal) {
4277 		jbd2_journal_destroy(sbi->s_journal);
4278 		sbi->s_journal = NULL;
4279 	}
4280 failed_mount3a:
4281 	ext4_es_unregister_shrinker(sbi);
4282 failed_mount3:
4283 	del_timer_sync(&sbi->s_err_report);
4284 	if (sbi->s_mmp_tsk)
4285 		kthread_stop(sbi->s_mmp_tsk);
4286 failed_mount2:
4287 	for (i = 0; i < db_count; i++)
4288 		brelse(sbi->s_group_desc[i]);
4289 	kvfree(sbi->s_group_desc);
4290 failed_mount:
4291 	if (sbi->s_chksum_driver)
4292 		crypto_free_shash(sbi->s_chksum_driver);
4293 	if (sbi->s_proc) {
4294 		remove_proc_entry("options", sbi->s_proc);
4295 		remove_proc_entry(sb->s_id, ext4_proc_root);
4296 	}
4297 #ifdef CONFIG_QUOTA
4298 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4299 		kfree(sbi->s_qf_names[i]);
4300 #endif
4301 	ext4_blkdev_remove(sbi);
4302 	brelse(bh);
4303 out_fail:
4304 	sb->s_fs_info = NULL;
4305 	kfree(sbi->s_blockgroup_lock);
4306 	kfree(sbi);
4307 out_free_orig:
4308 	kfree(orig_data);
4309 	return err ? err : ret;
4310 }
4311 
4312 /*
4313  * Setup any per-fs journal parameters now.  We'll do this both on
4314  * initial mount, once the journal has been initialised but before we've
4315  * done any recovery; and again on any subsequent remount.
4316  */
4317 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4318 {
4319 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4320 
4321 	journal->j_commit_interval = sbi->s_commit_interval;
4322 	journal->j_min_batch_time = sbi->s_min_batch_time;
4323 	journal->j_max_batch_time = sbi->s_max_batch_time;
4324 
4325 	write_lock(&journal->j_state_lock);
4326 	if (test_opt(sb, BARRIER))
4327 		journal->j_flags |= JBD2_BARRIER;
4328 	else
4329 		journal->j_flags &= ~JBD2_BARRIER;
4330 	if (test_opt(sb, DATA_ERR_ABORT))
4331 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4332 	else
4333 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4334 	write_unlock(&journal->j_state_lock);
4335 }
4336 
4337 static journal_t *ext4_get_journal(struct super_block *sb,
4338 				   unsigned int journal_inum)
4339 {
4340 	struct inode *journal_inode;
4341 	journal_t *journal;
4342 
4343 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4344 
4345 	/* First, test for the existence of a valid inode on disk.  Bad
4346 	 * things happen if we iget() an unused inode, as the subsequent
4347 	 * iput() will try to delete it. */
4348 
4349 	journal_inode = ext4_iget(sb, journal_inum);
4350 	if (IS_ERR(journal_inode)) {
4351 		ext4_msg(sb, KERN_ERR, "no journal found");
4352 		return NULL;
4353 	}
4354 	if (!journal_inode->i_nlink) {
4355 		make_bad_inode(journal_inode);
4356 		iput(journal_inode);
4357 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4358 		return NULL;
4359 	}
4360 
4361 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4362 		  journal_inode, journal_inode->i_size);
4363 	if (!S_ISREG(journal_inode->i_mode)) {
4364 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4365 		iput(journal_inode);
4366 		return NULL;
4367 	}
4368 
4369 	journal = jbd2_journal_init_inode(journal_inode);
4370 	if (!journal) {
4371 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4372 		iput(journal_inode);
4373 		return NULL;
4374 	}
4375 	journal->j_private = sb;
4376 	ext4_init_journal_params(sb, journal);
4377 	return journal;
4378 }
4379 
4380 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4381 				       dev_t j_dev)
4382 {
4383 	struct buffer_head *bh;
4384 	journal_t *journal;
4385 	ext4_fsblk_t start;
4386 	ext4_fsblk_t len;
4387 	int hblock, blocksize;
4388 	ext4_fsblk_t sb_block;
4389 	unsigned long offset;
4390 	struct ext4_super_block *es;
4391 	struct block_device *bdev;
4392 
4393 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4394 
4395 	bdev = ext4_blkdev_get(j_dev, sb);
4396 	if (bdev == NULL)
4397 		return NULL;
4398 
4399 	blocksize = sb->s_blocksize;
4400 	hblock = bdev_logical_block_size(bdev);
4401 	if (blocksize < hblock) {
4402 		ext4_msg(sb, KERN_ERR,
4403 			"blocksize too small for journal device");
4404 		goto out_bdev;
4405 	}
4406 
4407 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4408 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4409 	set_blocksize(bdev, blocksize);
4410 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4411 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4412 		       "external journal");
4413 		goto out_bdev;
4414 	}
4415 
4416 	es = (struct ext4_super_block *) (bh->b_data + offset);
4417 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4418 	    !(le32_to_cpu(es->s_feature_incompat) &
4419 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4420 		ext4_msg(sb, KERN_ERR, "external journal has "
4421 					"bad superblock");
4422 		brelse(bh);
4423 		goto out_bdev;
4424 	}
4425 
4426 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4427 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4428 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4429 		ext4_msg(sb, KERN_ERR, "external journal has "
4430 				       "corrupt superblock");
4431 		brelse(bh);
4432 		goto out_bdev;
4433 	}
4434 
4435 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4436 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4437 		brelse(bh);
4438 		goto out_bdev;
4439 	}
4440 
4441 	len = ext4_blocks_count(es);
4442 	start = sb_block + 1;
4443 	brelse(bh);	/* we're done with the superblock */
4444 
4445 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4446 					start, len, blocksize);
4447 	if (!journal) {
4448 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4449 		goto out_bdev;
4450 	}
4451 	journal->j_private = sb;
4452 	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4453 	wait_on_buffer(journal->j_sb_buffer);
4454 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4455 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4456 		goto out_journal;
4457 	}
4458 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4459 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4460 					"user (unsupported) - %d",
4461 			be32_to_cpu(journal->j_superblock->s_nr_users));
4462 		goto out_journal;
4463 	}
4464 	EXT4_SB(sb)->journal_bdev = bdev;
4465 	ext4_init_journal_params(sb, journal);
4466 	return journal;
4467 
4468 out_journal:
4469 	jbd2_journal_destroy(journal);
4470 out_bdev:
4471 	ext4_blkdev_put(bdev);
4472 	return NULL;
4473 }
4474 
4475 static int ext4_load_journal(struct super_block *sb,
4476 			     struct ext4_super_block *es,
4477 			     unsigned long journal_devnum)
4478 {
4479 	journal_t *journal;
4480 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4481 	dev_t journal_dev;
4482 	int err = 0;
4483 	int really_read_only;
4484 
4485 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4486 
4487 	if (journal_devnum &&
4488 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4489 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4490 			"numbers have changed");
4491 		journal_dev = new_decode_dev(journal_devnum);
4492 	} else
4493 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4494 
4495 	really_read_only = bdev_read_only(sb->s_bdev);
4496 
4497 	/*
4498 	 * Are we loading a blank journal or performing recovery after a
4499 	 * crash?  For recovery, we need to check in advance whether we
4500 	 * can get read-write access to the device.
4501 	 */
4502 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4503 		if (sb->s_flags & MS_RDONLY) {
4504 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4505 					"required on readonly filesystem");
4506 			if (really_read_only) {
4507 				ext4_msg(sb, KERN_ERR, "write access "
4508 					"unavailable, cannot proceed");
4509 				return -EROFS;
4510 			}
4511 			ext4_msg(sb, KERN_INFO, "write access will "
4512 			       "be enabled during recovery");
4513 		}
4514 	}
4515 
4516 	if (journal_inum && journal_dev) {
4517 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4518 		       "and inode journals!");
4519 		return -EINVAL;
4520 	}
4521 
4522 	if (journal_inum) {
4523 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4524 			return -EINVAL;
4525 	} else {
4526 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4527 			return -EINVAL;
4528 	}
4529 
4530 	if (!(journal->j_flags & JBD2_BARRIER))
4531 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4532 
4533 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4534 		err = jbd2_journal_wipe(journal, !really_read_only);
4535 	if (!err) {
4536 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4537 		if (save)
4538 			memcpy(save, ((char *) es) +
4539 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4540 		err = jbd2_journal_load(journal);
4541 		if (save)
4542 			memcpy(((char *) es) + EXT4_S_ERR_START,
4543 			       save, EXT4_S_ERR_LEN);
4544 		kfree(save);
4545 	}
4546 
4547 	if (err) {
4548 		ext4_msg(sb, KERN_ERR, "error loading journal");
4549 		jbd2_journal_destroy(journal);
4550 		return err;
4551 	}
4552 
4553 	EXT4_SB(sb)->s_journal = journal;
4554 	ext4_clear_journal_err(sb, es);
4555 
4556 	if (!really_read_only && journal_devnum &&
4557 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4558 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4559 
4560 		/* Make sure we flush the recovery flag to disk. */
4561 		ext4_commit_super(sb, 1);
4562 	}
4563 
4564 	return 0;
4565 }
4566 
4567 static int ext4_commit_super(struct super_block *sb, int sync)
4568 {
4569 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4570 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4571 	int error = 0;
4572 
4573 	if (!sbh || block_device_ejected(sb))
4574 		return error;
4575 	if (buffer_write_io_error(sbh)) {
4576 		/*
4577 		 * Oh, dear.  A previous attempt to write the
4578 		 * superblock failed.  This could happen because the
4579 		 * USB device was yanked out.  Or it could happen to
4580 		 * be a transient write error and maybe the block will
4581 		 * be remapped.  Nothing we can do but to retry the
4582 		 * write and hope for the best.
4583 		 */
4584 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4585 		       "superblock detected");
4586 		clear_buffer_write_io_error(sbh);
4587 		set_buffer_uptodate(sbh);
4588 	}
4589 	/*
4590 	 * If the file system is mounted read-only, don't update the
4591 	 * superblock write time.  This avoids updating the superblock
4592 	 * write time when we are mounting the root file system
4593 	 * read/only but we need to replay the journal; at that point,
4594 	 * for people who are east of GMT and who make their clock
4595 	 * tick in localtime for Windows bug-for-bug compatibility,
4596 	 * the clock is set in the future, and this will cause e2fsck
4597 	 * to complain and force a full file system check.
4598 	 */
4599 	if (!(sb->s_flags & MS_RDONLY))
4600 		es->s_wtime = cpu_to_le32(get_seconds());
4601 	if (sb->s_bdev->bd_part)
4602 		es->s_kbytes_written =
4603 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4604 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4605 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4606 	else
4607 		es->s_kbytes_written =
4608 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4609 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4610 		ext4_free_blocks_count_set(es,
4611 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4612 				&EXT4_SB(sb)->s_freeclusters_counter)));
4613 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4614 		es->s_free_inodes_count =
4615 			cpu_to_le32(percpu_counter_sum_positive(
4616 				&EXT4_SB(sb)->s_freeinodes_counter));
4617 	BUFFER_TRACE(sbh, "marking dirty");
4618 	ext4_superblock_csum_set(sb);
4619 	mark_buffer_dirty(sbh);
4620 	if (sync) {
4621 		error = sync_dirty_buffer(sbh);
4622 		if (error)
4623 			return error;
4624 
4625 		error = buffer_write_io_error(sbh);
4626 		if (error) {
4627 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4628 			       "superblock");
4629 			clear_buffer_write_io_error(sbh);
4630 			set_buffer_uptodate(sbh);
4631 		}
4632 	}
4633 	return error;
4634 }
4635 
4636 /*
4637  * Have we just finished recovery?  If so, and if we are mounting (or
4638  * remounting) the filesystem readonly, then we will end up with a
4639  * consistent fs on disk.  Record that fact.
4640  */
4641 static void ext4_mark_recovery_complete(struct super_block *sb,
4642 					struct ext4_super_block *es)
4643 {
4644 	journal_t *journal = EXT4_SB(sb)->s_journal;
4645 
4646 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4647 		BUG_ON(journal != NULL);
4648 		return;
4649 	}
4650 	jbd2_journal_lock_updates(journal);
4651 	if (jbd2_journal_flush(journal) < 0)
4652 		goto out;
4653 
4654 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4655 	    sb->s_flags & MS_RDONLY) {
4656 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4657 		ext4_commit_super(sb, 1);
4658 	}
4659 
4660 out:
4661 	jbd2_journal_unlock_updates(journal);
4662 }
4663 
4664 /*
4665  * If we are mounting (or read-write remounting) a filesystem whose journal
4666  * has recorded an error from a previous lifetime, move that error to the
4667  * main filesystem now.
4668  */
4669 static void ext4_clear_journal_err(struct super_block *sb,
4670 				   struct ext4_super_block *es)
4671 {
4672 	journal_t *journal;
4673 	int j_errno;
4674 	const char *errstr;
4675 
4676 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4677 
4678 	journal = EXT4_SB(sb)->s_journal;
4679 
4680 	/*
4681 	 * Now check for any error status which may have been recorded in the
4682 	 * journal by a prior ext4_error() or ext4_abort()
4683 	 */
4684 
4685 	j_errno = jbd2_journal_errno(journal);
4686 	if (j_errno) {
4687 		char nbuf[16];
4688 
4689 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4690 		ext4_warning(sb, "Filesystem error recorded "
4691 			     "from previous mount: %s", errstr);
4692 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4693 
4694 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4695 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4696 		ext4_commit_super(sb, 1);
4697 
4698 		jbd2_journal_clear_err(journal);
4699 		jbd2_journal_update_sb_errno(journal);
4700 	}
4701 }
4702 
4703 /*
4704  * Force the running and committing transactions to commit,
4705  * and wait on the commit.
4706  */
4707 int ext4_force_commit(struct super_block *sb)
4708 {
4709 	journal_t *journal;
4710 
4711 	if (sb->s_flags & MS_RDONLY)
4712 		return 0;
4713 
4714 	journal = EXT4_SB(sb)->s_journal;
4715 	return ext4_journal_force_commit(journal);
4716 }
4717 
4718 static int ext4_sync_fs(struct super_block *sb, int wait)
4719 {
4720 	int ret = 0;
4721 	tid_t target;
4722 	bool needs_barrier = false;
4723 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4724 
4725 	trace_ext4_sync_fs(sb, wait);
4726 	flush_workqueue(sbi->rsv_conversion_wq);
4727 	/*
4728 	 * Writeback quota in non-journalled quota case - journalled quota has
4729 	 * no dirty dquots
4730 	 */
4731 	dquot_writeback_dquots(sb, -1);
4732 	/*
4733 	 * Data writeback is possible w/o journal transaction, so barrier must
4734 	 * being sent at the end of the function. But we can skip it if
4735 	 * transaction_commit will do it for us.
4736 	 */
4737 	if (sbi->s_journal) {
4738 		target = jbd2_get_latest_transaction(sbi->s_journal);
4739 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4740 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4741 			needs_barrier = true;
4742 
4743 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4744 			if (wait)
4745 				ret = jbd2_log_wait_commit(sbi->s_journal,
4746 							   target);
4747 		}
4748 	} else if (wait && test_opt(sb, BARRIER))
4749 		needs_barrier = true;
4750 	if (needs_barrier) {
4751 		int err;
4752 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4753 		if (!ret)
4754 			ret = err;
4755 	}
4756 
4757 	return ret;
4758 }
4759 
4760 /*
4761  * LVM calls this function before a (read-only) snapshot is created.  This
4762  * gives us a chance to flush the journal completely and mark the fs clean.
4763  *
4764  * Note that only this function cannot bring a filesystem to be in a clean
4765  * state independently. It relies on upper layer to stop all data & metadata
4766  * modifications.
4767  */
4768 static int ext4_freeze(struct super_block *sb)
4769 {
4770 	int error = 0;
4771 	journal_t *journal;
4772 
4773 	if (sb->s_flags & MS_RDONLY)
4774 		return 0;
4775 
4776 	journal = EXT4_SB(sb)->s_journal;
4777 
4778 	if (journal) {
4779 		/* Now we set up the journal barrier. */
4780 		jbd2_journal_lock_updates(journal);
4781 
4782 		/*
4783 		 * Don't clear the needs_recovery flag if we failed to
4784 		 * flush the journal.
4785 		 */
4786 		error = jbd2_journal_flush(journal);
4787 		if (error < 0)
4788 			goto out;
4789 	}
4790 
4791 	/* Journal blocked and flushed, clear needs_recovery flag. */
4792 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4793 	error = ext4_commit_super(sb, 1);
4794 out:
4795 	if (journal)
4796 		/* we rely on upper layer to stop further updates */
4797 		jbd2_journal_unlock_updates(journal);
4798 	return error;
4799 }
4800 
4801 /*
4802  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4803  * flag here, even though the filesystem is not technically dirty yet.
4804  */
4805 static int ext4_unfreeze(struct super_block *sb)
4806 {
4807 	if (sb->s_flags & MS_RDONLY)
4808 		return 0;
4809 
4810 	/* Reset the needs_recovery flag before the fs is unlocked. */
4811 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4812 	ext4_commit_super(sb, 1);
4813 	return 0;
4814 }
4815 
4816 /*
4817  * Structure to save mount options for ext4_remount's benefit
4818  */
4819 struct ext4_mount_options {
4820 	unsigned long s_mount_opt;
4821 	unsigned long s_mount_opt2;
4822 	kuid_t s_resuid;
4823 	kgid_t s_resgid;
4824 	unsigned long s_commit_interval;
4825 	u32 s_min_batch_time, s_max_batch_time;
4826 #ifdef CONFIG_QUOTA
4827 	int s_jquota_fmt;
4828 	char *s_qf_names[EXT4_MAXQUOTAS];
4829 #endif
4830 };
4831 
4832 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4833 {
4834 	struct ext4_super_block *es;
4835 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4836 	unsigned long old_sb_flags;
4837 	struct ext4_mount_options old_opts;
4838 	int enable_quota = 0;
4839 	ext4_group_t g;
4840 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4841 	int err = 0;
4842 #ifdef CONFIG_QUOTA
4843 	int i, j;
4844 #endif
4845 	char *orig_data = kstrdup(data, GFP_KERNEL);
4846 
4847 	/* Store the original options */
4848 	old_sb_flags = sb->s_flags;
4849 	old_opts.s_mount_opt = sbi->s_mount_opt;
4850 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4851 	old_opts.s_resuid = sbi->s_resuid;
4852 	old_opts.s_resgid = sbi->s_resgid;
4853 	old_opts.s_commit_interval = sbi->s_commit_interval;
4854 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4855 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4856 #ifdef CONFIG_QUOTA
4857 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4858 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4859 		if (sbi->s_qf_names[i]) {
4860 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4861 							 GFP_KERNEL);
4862 			if (!old_opts.s_qf_names[i]) {
4863 				for (j = 0; j < i; j++)
4864 					kfree(old_opts.s_qf_names[j]);
4865 				kfree(orig_data);
4866 				return -ENOMEM;
4867 			}
4868 		} else
4869 			old_opts.s_qf_names[i] = NULL;
4870 #endif
4871 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4872 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4873 
4874 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4875 		err = -EINVAL;
4876 		goto restore_opts;
4877 	}
4878 
4879 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4880 	    test_opt(sb, JOURNAL_CHECKSUM)) {
4881 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4882 			 "during remount not supported; ignoring");
4883 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4884 	}
4885 
4886 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4887 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4888 			ext4_msg(sb, KERN_ERR, "can't mount with "
4889 				 "both data=journal and delalloc");
4890 			err = -EINVAL;
4891 			goto restore_opts;
4892 		}
4893 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4894 			ext4_msg(sb, KERN_ERR, "can't mount with "
4895 				 "both data=journal and dioread_nolock");
4896 			err = -EINVAL;
4897 			goto restore_opts;
4898 		}
4899 		if (test_opt(sb, DAX)) {
4900 			ext4_msg(sb, KERN_ERR, "can't mount with "
4901 				 "both data=journal and dax");
4902 			err = -EINVAL;
4903 			goto restore_opts;
4904 		}
4905 	}
4906 
4907 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4908 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4909 			"dax flag with busy inodes while remounting");
4910 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4911 	}
4912 
4913 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4914 		ext4_abort(sb, "Abort forced by user");
4915 
4916 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4917 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4918 
4919 	es = sbi->s_es;
4920 
4921 	if (sbi->s_journal) {
4922 		ext4_init_journal_params(sb, sbi->s_journal);
4923 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4924 	}
4925 
4926 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4927 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4928 			err = -EROFS;
4929 			goto restore_opts;
4930 		}
4931 
4932 		if (*flags & MS_RDONLY) {
4933 			err = sync_filesystem(sb);
4934 			if (err < 0)
4935 				goto restore_opts;
4936 			err = dquot_suspend(sb, -1);
4937 			if (err < 0)
4938 				goto restore_opts;
4939 
4940 			/*
4941 			 * First of all, the unconditional stuff we have to do
4942 			 * to disable replay of the journal when we next remount
4943 			 */
4944 			sb->s_flags |= MS_RDONLY;
4945 
4946 			/*
4947 			 * OK, test if we are remounting a valid rw partition
4948 			 * readonly, and if so set the rdonly flag and then
4949 			 * mark the partition as valid again.
4950 			 */
4951 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4952 			    (sbi->s_mount_state & EXT4_VALID_FS))
4953 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4954 
4955 			if (sbi->s_journal)
4956 				ext4_mark_recovery_complete(sb, es);
4957 		} else {
4958 			/* Make sure we can mount this feature set readwrite */
4959 			if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4960 					EXT4_FEATURE_RO_COMPAT_READONLY) ||
4961 			    !ext4_feature_set_ok(sb, 0)) {
4962 				err = -EROFS;
4963 				goto restore_opts;
4964 			}
4965 			/*
4966 			 * Make sure the group descriptor checksums
4967 			 * are sane.  If they aren't, refuse to remount r/w.
4968 			 */
4969 			for (g = 0; g < sbi->s_groups_count; g++) {
4970 				struct ext4_group_desc *gdp =
4971 					ext4_get_group_desc(sb, g, NULL);
4972 
4973 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4974 					ext4_msg(sb, KERN_ERR,
4975 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4976 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4977 					       le16_to_cpu(gdp->bg_checksum));
4978 					err = -EINVAL;
4979 					goto restore_opts;
4980 				}
4981 			}
4982 
4983 			/*
4984 			 * If we have an unprocessed orphan list hanging
4985 			 * around from a previously readonly bdev mount,
4986 			 * require a full umount/remount for now.
4987 			 */
4988 			if (es->s_last_orphan) {
4989 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4990 				       "remount RDWR because of unprocessed "
4991 				       "orphan inode list.  Please "
4992 				       "umount/remount instead");
4993 				err = -EINVAL;
4994 				goto restore_opts;
4995 			}
4996 
4997 			/*
4998 			 * Mounting a RDONLY partition read-write, so reread
4999 			 * and store the current valid flag.  (It may have
5000 			 * been changed by e2fsck since we originally mounted
5001 			 * the partition.)
5002 			 */
5003 			if (sbi->s_journal)
5004 				ext4_clear_journal_err(sb, es);
5005 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5006 			if (!ext4_setup_super(sb, es, 0))
5007 				sb->s_flags &= ~MS_RDONLY;
5008 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
5009 						     EXT4_FEATURE_INCOMPAT_MMP))
5010 				if (ext4_multi_mount_protect(sb,
5011 						le64_to_cpu(es->s_mmp_block))) {
5012 					err = -EROFS;
5013 					goto restore_opts;
5014 				}
5015 			enable_quota = 1;
5016 		}
5017 	}
5018 
5019 	/*
5020 	 * Reinitialize lazy itable initialization thread based on
5021 	 * current settings
5022 	 */
5023 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5024 		ext4_unregister_li_request(sb);
5025 	else {
5026 		ext4_group_t first_not_zeroed;
5027 		first_not_zeroed = ext4_has_uninit_itable(sb);
5028 		ext4_register_li_request(sb, first_not_zeroed);
5029 	}
5030 
5031 	ext4_setup_system_zone(sb);
5032 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5033 		ext4_commit_super(sb, 1);
5034 
5035 #ifdef CONFIG_QUOTA
5036 	/* Release old quota file names */
5037 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5038 		kfree(old_opts.s_qf_names[i]);
5039 	if (enable_quota) {
5040 		if (sb_any_quota_suspended(sb))
5041 			dquot_resume(sb, -1);
5042 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5043 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
5044 			err = ext4_enable_quotas(sb);
5045 			if (err)
5046 				goto restore_opts;
5047 		}
5048 	}
5049 #endif
5050 
5051 	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5052 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5053 	kfree(orig_data);
5054 	return 0;
5055 
5056 restore_opts:
5057 	sb->s_flags = old_sb_flags;
5058 	sbi->s_mount_opt = old_opts.s_mount_opt;
5059 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5060 	sbi->s_resuid = old_opts.s_resuid;
5061 	sbi->s_resgid = old_opts.s_resgid;
5062 	sbi->s_commit_interval = old_opts.s_commit_interval;
5063 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5064 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5065 #ifdef CONFIG_QUOTA
5066 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5067 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5068 		kfree(sbi->s_qf_names[i]);
5069 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5070 	}
5071 #endif
5072 	kfree(orig_data);
5073 	return err;
5074 }
5075 
5076 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5077 {
5078 	struct super_block *sb = dentry->d_sb;
5079 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5080 	struct ext4_super_block *es = sbi->s_es;
5081 	ext4_fsblk_t overhead = 0, resv_blocks;
5082 	u64 fsid;
5083 	s64 bfree;
5084 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5085 
5086 	if (!test_opt(sb, MINIX_DF))
5087 		overhead = sbi->s_overhead;
5088 
5089 	buf->f_type = EXT4_SUPER_MAGIC;
5090 	buf->f_bsize = sb->s_blocksize;
5091 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5092 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5093 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5094 	/* prevent underflow in case that few free space is available */
5095 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5096 	buf->f_bavail = buf->f_bfree -
5097 			(ext4_r_blocks_count(es) + resv_blocks);
5098 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5099 		buf->f_bavail = 0;
5100 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5101 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5102 	buf->f_namelen = EXT4_NAME_LEN;
5103 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5104 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5105 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5106 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5107 
5108 	return 0;
5109 }
5110 
5111 /* Helper function for writing quotas on sync - we need to start transaction
5112  * before quota file is locked for write. Otherwise the are possible deadlocks:
5113  * Process 1                         Process 2
5114  * ext4_create()                     quota_sync()
5115  *   jbd2_journal_start()                  write_dquot()
5116  *   dquot_initialize()                         down(dqio_mutex)
5117  *     down(dqio_mutex)                    jbd2_journal_start()
5118  *
5119  */
5120 
5121 #ifdef CONFIG_QUOTA
5122 
5123 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5124 {
5125 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5126 }
5127 
5128 static int ext4_write_dquot(struct dquot *dquot)
5129 {
5130 	int ret, err;
5131 	handle_t *handle;
5132 	struct inode *inode;
5133 
5134 	inode = dquot_to_inode(dquot);
5135 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5136 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5137 	if (IS_ERR(handle))
5138 		return PTR_ERR(handle);
5139 	ret = dquot_commit(dquot);
5140 	err = ext4_journal_stop(handle);
5141 	if (!ret)
5142 		ret = err;
5143 	return ret;
5144 }
5145 
5146 static int ext4_acquire_dquot(struct dquot *dquot)
5147 {
5148 	int ret, err;
5149 	handle_t *handle;
5150 
5151 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5152 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5153 	if (IS_ERR(handle))
5154 		return PTR_ERR(handle);
5155 	ret = dquot_acquire(dquot);
5156 	err = ext4_journal_stop(handle);
5157 	if (!ret)
5158 		ret = err;
5159 	return ret;
5160 }
5161 
5162 static int ext4_release_dquot(struct dquot *dquot)
5163 {
5164 	int ret, err;
5165 	handle_t *handle;
5166 
5167 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5168 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5169 	if (IS_ERR(handle)) {
5170 		/* Release dquot anyway to avoid endless cycle in dqput() */
5171 		dquot_release(dquot);
5172 		return PTR_ERR(handle);
5173 	}
5174 	ret = dquot_release(dquot);
5175 	err = ext4_journal_stop(handle);
5176 	if (!ret)
5177 		ret = err;
5178 	return ret;
5179 }
5180 
5181 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5182 {
5183 	struct super_block *sb = dquot->dq_sb;
5184 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5185 
5186 	/* Are we journaling quotas? */
5187 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5188 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5189 		dquot_mark_dquot_dirty(dquot);
5190 		return ext4_write_dquot(dquot);
5191 	} else {
5192 		return dquot_mark_dquot_dirty(dquot);
5193 	}
5194 }
5195 
5196 static int ext4_write_info(struct super_block *sb, int type)
5197 {
5198 	int ret, err;
5199 	handle_t *handle;
5200 
5201 	/* Data block + inode block */
5202 	handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5203 	if (IS_ERR(handle))
5204 		return PTR_ERR(handle);
5205 	ret = dquot_commit_info(sb, type);
5206 	err = ext4_journal_stop(handle);
5207 	if (!ret)
5208 		ret = err;
5209 	return ret;
5210 }
5211 
5212 /*
5213  * Turn on quotas during mount time - we need to find
5214  * the quota file and such...
5215  */
5216 static int ext4_quota_on_mount(struct super_block *sb, int type)
5217 {
5218 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5219 					EXT4_SB(sb)->s_jquota_fmt, type);
5220 }
5221 
5222 /*
5223  * Standard function to be called on quota_on
5224  */
5225 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5226 			 struct path *path)
5227 {
5228 	int err;
5229 
5230 	if (!test_opt(sb, QUOTA))
5231 		return -EINVAL;
5232 
5233 	/* Quotafile not on the same filesystem? */
5234 	if (path->dentry->d_sb != sb)
5235 		return -EXDEV;
5236 	/* Journaling quota? */
5237 	if (EXT4_SB(sb)->s_qf_names[type]) {
5238 		/* Quotafile not in fs root? */
5239 		if (path->dentry->d_parent != sb->s_root)
5240 			ext4_msg(sb, KERN_WARNING,
5241 				"Quota file not on filesystem root. "
5242 				"Journaled quota will not work");
5243 	}
5244 
5245 	/*
5246 	 * When we journal data on quota file, we have to flush journal to see
5247 	 * all updates to the file when we bypass pagecache...
5248 	 */
5249 	if (EXT4_SB(sb)->s_journal &&
5250 	    ext4_should_journal_data(path->dentry->d_inode)) {
5251 		/*
5252 		 * We don't need to lock updates but journal_flush() could
5253 		 * otherwise be livelocked...
5254 		 */
5255 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5256 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5257 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5258 		if (err)
5259 			return err;
5260 	}
5261 
5262 	return dquot_quota_on(sb, type, format_id, path);
5263 }
5264 
5265 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5266 			     unsigned int flags)
5267 {
5268 	int err;
5269 	struct inode *qf_inode;
5270 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5271 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5272 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5273 	};
5274 
5275 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5276 
5277 	if (!qf_inums[type])
5278 		return -EPERM;
5279 
5280 	qf_inode = ext4_iget(sb, qf_inums[type]);
5281 	if (IS_ERR(qf_inode)) {
5282 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5283 		return PTR_ERR(qf_inode);
5284 	}
5285 
5286 	/* Don't account quota for quota files to avoid recursion */
5287 	qf_inode->i_flags |= S_NOQUOTA;
5288 	err = dquot_enable(qf_inode, type, format_id, flags);
5289 	iput(qf_inode);
5290 
5291 	return err;
5292 }
5293 
5294 /* Enable usage tracking for all quota types. */
5295 static int ext4_enable_quotas(struct super_block *sb)
5296 {
5297 	int type, err = 0;
5298 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5299 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5300 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5301 	};
5302 
5303 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5304 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5305 		if (qf_inums[type]) {
5306 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5307 						DQUOT_USAGE_ENABLED);
5308 			if (err) {
5309 				ext4_warning(sb,
5310 					"Failed to enable quota tracking "
5311 					"(type=%d, err=%d). Please run "
5312 					"e2fsck to fix.", type, err);
5313 				return err;
5314 			}
5315 		}
5316 	}
5317 	return 0;
5318 }
5319 
5320 static int ext4_quota_off(struct super_block *sb, int type)
5321 {
5322 	struct inode *inode = sb_dqopt(sb)->files[type];
5323 	handle_t *handle;
5324 
5325 	/* Force all delayed allocation blocks to be allocated.
5326 	 * Caller already holds s_umount sem */
5327 	if (test_opt(sb, DELALLOC))
5328 		sync_filesystem(sb);
5329 
5330 	if (!inode)
5331 		goto out;
5332 
5333 	/* Update modification times of quota files when userspace can
5334 	 * start looking at them */
5335 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5336 	if (IS_ERR(handle))
5337 		goto out;
5338 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5339 	ext4_mark_inode_dirty(handle, inode);
5340 	ext4_journal_stop(handle);
5341 
5342 out:
5343 	return dquot_quota_off(sb, type);
5344 }
5345 
5346 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5347  * acquiring the locks... As quota files are never truncated and quota code
5348  * itself serializes the operations (and no one else should touch the files)
5349  * we don't have to be afraid of races */
5350 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5351 			       size_t len, loff_t off)
5352 {
5353 	struct inode *inode = sb_dqopt(sb)->files[type];
5354 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5355 	int offset = off & (sb->s_blocksize - 1);
5356 	int tocopy;
5357 	size_t toread;
5358 	struct buffer_head *bh;
5359 	loff_t i_size = i_size_read(inode);
5360 
5361 	if (off > i_size)
5362 		return 0;
5363 	if (off+len > i_size)
5364 		len = i_size-off;
5365 	toread = len;
5366 	while (toread > 0) {
5367 		tocopy = sb->s_blocksize - offset < toread ?
5368 				sb->s_blocksize - offset : toread;
5369 		bh = ext4_bread(NULL, inode, blk, 0);
5370 		if (IS_ERR(bh))
5371 			return PTR_ERR(bh);
5372 		if (!bh)	/* A hole? */
5373 			memset(data, 0, tocopy);
5374 		else
5375 			memcpy(data, bh->b_data+offset, tocopy);
5376 		brelse(bh);
5377 		offset = 0;
5378 		toread -= tocopy;
5379 		data += tocopy;
5380 		blk++;
5381 	}
5382 	return len;
5383 }
5384 
5385 /* Write to quotafile (we know the transaction is already started and has
5386  * enough credits) */
5387 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5388 				const char *data, size_t len, loff_t off)
5389 {
5390 	struct inode *inode = sb_dqopt(sb)->files[type];
5391 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5392 	int err, offset = off & (sb->s_blocksize - 1);
5393 	struct buffer_head *bh;
5394 	handle_t *handle = journal_current_handle();
5395 
5396 	if (EXT4_SB(sb)->s_journal && !handle) {
5397 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5398 			" cancelled because transaction is not started",
5399 			(unsigned long long)off, (unsigned long long)len);
5400 		return -EIO;
5401 	}
5402 	/*
5403 	 * Since we account only one data block in transaction credits,
5404 	 * then it is impossible to cross a block boundary.
5405 	 */
5406 	if (sb->s_blocksize - offset < len) {
5407 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5408 			" cancelled because not block aligned",
5409 			(unsigned long long)off, (unsigned long long)len);
5410 		return -EIO;
5411 	}
5412 
5413 	bh = ext4_bread(handle, inode, blk, 1);
5414 	if (IS_ERR(bh))
5415 		return PTR_ERR(bh);
5416 	if (!bh)
5417 		goto out;
5418 	BUFFER_TRACE(bh, "get write access");
5419 	err = ext4_journal_get_write_access(handle, bh);
5420 	if (err) {
5421 		brelse(bh);
5422 		return err;
5423 	}
5424 	lock_buffer(bh);
5425 	memcpy(bh->b_data+offset, data, len);
5426 	flush_dcache_page(bh->b_page);
5427 	unlock_buffer(bh);
5428 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5429 	brelse(bh);
5430 out:
5431 	if (inode->i_size < off + len) {
5432 		i_size_write(inode, off + len);
5433 		EXT4_I(inode)->i_disksize = inode->i_size;
5434 		ext4_mark_inode_dirty(handle, inode);
5435 	}
5436 	return len;
5437 }
5438 
5439 #endif
5440 
5441 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5442 		       const char *dev_name, void *data)
5443 {
5444 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5445 }
5446 
5447 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5448 static inline void register_as_ext2(void)
5449 {
5450 	int err = register_filesystem(&ext2_fs_type);
5451 	if (err)
5452 		printk(KERN_WARNING
5453 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5454 }
5455 
5456 static inline void unregister_as_ext2(void)
5457 {
5458 	unregister_filesystem(&ext2_fs_type);
5459 }
5460 
5461 static inline int ext2_feature_set_ok(struct super_block *sb)
5462 {
5463 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5464 		return 0;
5465 	if (sb->s_flags & MS_RDONLY)
5466 		return 1;
5467 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5468 		return 0;
5469 	return 1;
5470 }
5471 #else
5472 static inline void register_as_ext2(void) { }
5473 static inline void unregister_as_ext2(void) { }
5474 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5475 #endif
5476 
5477 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5478 static inline void register_as_ext3(void)
5479 {
5480 	int err = register_filesystem(&ext3_fs_type);
5481 	if (err)
5482 		printk(KERN_WARNING
5483 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5484 }
5485 
5486 static inline void unregister_as_ext3(void)
5487 {
5488 	unregister_filesystem(&ext3_fs_type);
5489 }
5490 
5491 static inline int ext3_feature_set_ok(struct super_block *sb)
5492 {
5493 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5494 		return 0;
5495 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5496 		return 0;
5497 	if (sb->s_flags & MS_RDONLY)
5498 		return 1;
5499 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5500 		return 0;
5501 	return 1;
5502 }
5503 #else
5504 static inline void register_as_ext3(void) { }
5505 static inline void unregister_as_ext3(void) { }
5506 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5507 #endif
5508 
5509 static struct file_system_type ext4_fs_type = {
5510 	.owner		= THIS_MODULE,
5511 	.name		= "ext4",
5512 	.mount		= ext4_mount,
5513 	.kill_sb	= kill_block_super,
5514 	.fs_flags	= FS_REQUIRES_DEV,
5515 };
5516 MODULE_ALIAS_FS("ext4");
5517 
5518 static int __init ext4_init_feat_adverts(void)
5519 {
5520 	struct ext4_features *ef;
5521 	int ret = -ENOMEM;
5522 
5523 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5524 	if (!ef)
5525 		goto out;
5526 
5527 	ef->f_kobj.kset = ext4_kset;
5528 	init_completion(&ef->f_kobj_unregister);
5529 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5530 				   "features");
5531 	if (ret) {
5532 		kfree(ef);
5533 		goto out;
5534 	}
5535 
5536 	ext4_feat = ef;
5537 	ret = 0;
5538 out:
5539 	return ret;
5540 }
5541 
5542 static void ext4_exit_feat_adverts(void)
5543 {
5544 	kobject_put(&ext4_feat->f_kobj);
5545 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5546 	kfree(ext4_feat);
5547 }
5548 
5549 /* Shared across all ext4 file systems */
5550 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5551 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5552 
5553 static int __init ext4_init_fs(void)
5554 {
5555 	int i, err;
5556 
5557 	ext4_li_info = NULL;
5558 	mutex_init(&ext4_li_mtx);
5559 
5560 	/* Build-time check for flags consistency */
5561 	ext4_check_flag_values();
5562 
5563 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5564 		mutex_init(&ext4__aio_mutex[i]);
5565 		init_waitqueue_head(&ext4__ioend_wq[i]);
5566 	}
5567 
5568 	err = ext4_init_es();
5569 	if (err)
5570 		return err;
5571 
5572 	err = ext4_init_pageio();
5573 	if (err)
5574 		goto out7;
5575 
5576 	err = ext4_init_system_zone();
5577 	if (err)
5578 		goto out6;
5579 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5580 	if (!ext4_kset) {
5581 		err = -ENOMEM;
5582 		goto out5;
5583 	}
5584 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5585 
5586 	err = ext4_init_feat_adverts();
5587 	if (err)
5588 		goto out4;
5589 
5590 	err = ext4_init_mballoc();
5591 	if (err)
5592 		goto out2;
5593 	else
5594 		ext4_mballoc_ready = 1;
5595 	err = init_inodecache();
5596 	if (err)
5597 		goto out1;
5598 	register_as_ext3();
5599 	register_as_ext2();
5600 	err = register_filesystem(&ext4_fs_type);
5601 	if (err)
5602 		goto out;
5603 
5604 	return 0;
5605 out:
5606 	unregister_as_ext2();
5607 	unregister_as_ext3();
5608 	destroy_inodecache();
5609 out1:
5610 	ext4_mballoc_ready = 0;
5611 	ext4_exit_mballoc();
5612 out2:
5613 	ext4_exit_feat_adverts();
5614 out4:
5615 	if (ext4_proc_root)
5616 		remove_proc_entry("fs/ext4", NULL);
5617 	kset_unregister(ext4_kset);
5618 out5:
5619 	ext4_exit_system_zone();
5620 out6:
5621 	ext4_exit_pageio();
5622 out7:
5623 	ext4_exit_es();
5624 
5625 	return err;
5626 }
5627 
5628 static void __exit ext4_exit_fs(void)
5629 {
5630 	ext4_destroy_lazyinit_thread();
5631 	unregister_as_ext2();
5632 	unregister_as_ext3();
5633 	unregister_filesystem(&ext4_fs_type);
5634 	destroy_inodecache();
5635 	ext4_exit_mballoc();
5636 	ext4_exit_feat_adverts();
5637 	remove_proc_entry("fs/ext4", NULL);
5638 	kset_unregister(ext4_kset);
5639 	ext4_exit_system_zone();
5640 	ext4_exit_pageio();
5641 	ext4_exit_es();
5642 }
5643 
5644 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5645 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5646 MODULE_LICENSE("GPL");
5647 module_init(ext4_init_fs)
5648 module_exit(ext4_exit_fs)
5649