xref: /openbmc/linux/fs/ext4/super.c (revision eb3fcf00)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/slab.h>
25 #include <linux/init.h>
26 #include <linux/blkdev.h>
27 #include <linux/backing-dev.h>
28 #include <linux/parser.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/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 static struct ratelimit_state ext4_mount_msg_ratelimit;
64 
65 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
66 			     unsigned long journal_devnum);
67 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
68 static int ext4_commit_super(struct super_block *sb, int sync);
69 static void ext4_mark_recovery_complete(struct super_block *sb,
70 					struct ext4_super_block *es);
71 static void ext4_clear_journal_err(struct super_block *sb,
72 				   struct ext4_super_block *es);
73 static int ext4_sync_fs(struct super_block *sb, int wait);
74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
76 static int ext4_unfreeze(struct super_block *sb);
77 static int ext4_freeze(struct super_block *sb);
78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
79 		       const char *dev_name, void *data);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
83 static void ext4_destroy_lazyinit_thread(void);
84 static void ext4_unregister_li_request(struct super_block *sb);
85 static void ext4_clear_request_list(void);
86 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
87 
88 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
89 static struct file_system_type ext2_fs_type = {
90 	.owner		= THIS_MODULE,
91 	.name		= "ext2",
92 	.mount		= ext4_mount,
93 	.kill_sb	= kill_block_super,
94 	.fs_flags	= FS_REQUIRES_DEV,
95 };
96 MODULE_ALIAS_FS("ext2");
97 MODULE_ALIAS("ext2");
98 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
99 #else
100 #define IS_EXT2_SB(sb) (0)
101 #endif
102 
103 
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 
115 static int ext4_verify_csum_type(struct super_block *sb,
116 				 struct ext4_super_block *es)
117 {
118 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
119 					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
120 		return 1;
121 
122 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
123 }
124 
125 static __le32 ext4_superblock_csum(struct super_block *sb,
126 				   struct ext4_super_block *es)
127 {
128 	struct ext4_sb_info *sbi = EXT4_SB(sb);
129 	int offset = offsetof(struct ext4_super_block, s_checksum);
130 	__u32 csum;
131 
132 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
133 
134 	return cpu_to_le32(csum);
135 }
136 
137 static int ext4_superblock_csum_verify(struct super_block *sb,
138 				       struct ext4_super_block *es)
139 {
140 	if (!ext4_has_metadata_csum(sb))
141 		return 1;
142 
143 	return es->s_checksum == ext4_superblock_csum(sb, es);
144 }
145 
146 void ext4_superblock_csum_set(struct super_block *sb)
147 {
148 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
149 
150 	if (!ext4_has_metadata_csum(sb))
151 		return;
152 
153 	es->s_checksum = ext4_superblock_csum(sb, es);
154 }
155 
156 void *ext4_kvmalloc(size_t size, gfp_t flags)
157 {
158 	void *ret;
159 
160 	ret = kmalloc(size, flags | __GFP_NOWARN);
161 	if (!ret)
162 		ret = __vmalloc(size, flags, PAGE_KERNEL);
163 	return ret;
164 }
165 
166 void *ext4_kvzalloc(size_t size, gfp_t flags)
167 {
168 	void *ret;
169 
170 	ret = kzalloc(size, flags | __GFP_NOWARN);
171 	if (!ret)
172 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
173 	return ret;
174 }
175 
176 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
177 			       struct ext4_group_desc *bg)
178 {
179 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
180 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
181 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
182 }
183 
184 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
185 			       struct ext4_group_desc *bg)
186 {
187 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
188 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
189 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
190 }
191 
192 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
193 			      struct ext4_group_desc *bg)
194 {
195 	return le32_to_cpu(bg->bg_inode_table_lo) |
196 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
197 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
198 }
199 
200 __u32 ext4_free_group_clusters(struct super_block *sb,
201 			       struct ext4_group_desc *bg)
202 {
203 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
204 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
205 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
206 }
207 
208 __u32 ext4_free_inodes_count(struct super_block *sb,
209 			      struct ext4_group_desc *bg)
210 {
211 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
212 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
213 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
214 }
215 
216 __u32 ext4_used_dirs_count(struct super_block *sb,
217 			      struct ext4_group_desc *bg)
218 {
219 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
220 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
221 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
222 }
223 
224 __u32 ext4_itable_unused_count(struct super_block *sb,
225 			      struct ext4_group_desc *bg)
226 {
227 	return le16_to_cpu(bg->bg_itable_unused_lo) |
228 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
229 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
230 }
231 
232 void ext4_block_bitmap_set(struct super_block *sb,
233 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
234 {
235 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
236 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
237 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
238 }
239 
240 void ext4_inode_bitmap_set(struct super_block *sb,
241 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
242 {
243 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
244 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
245 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
246 }
247 
248 void ext4_inode_table_set(struct super_block *sb,
249 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
250 {
251 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
252 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
253 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
254 }
255 
256 void ext4_free_group_clusters_set(struct super_block *sb,
257 				  struct ext4_group_desc *bg, __u32 count)
258 {
259 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
260 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
261 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
262 }
263 
264 void ext4_free_inodes_set(struct super_block *sb,
265 			  struct ext4_group_desc *bg, __u32 count)
266 {
267 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
268 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
269 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
270 }
271 
272 void ext4_used_dirs_set(struct super_block *sb,
273 			  struct ext4_group_desc *bg, __u32 count)
274 {
275 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
276 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
277 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
278 }
279 
280 void ext4_itable_unused_set(struct super_block *sb,
281 			  struct ext4_group_desc *bg, __u32 count)
282 {
283 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
284 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
285 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
286 }
287 
288 
289 static void __save_error_info(struct super_block *sb, const char *func,
290 			    unsigned int line)
291 {
292 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
293 
294 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
295 	if (bdev_read_only(sb->s_bdev))
296 		return;
297 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
298 	es->s_last_error_time = cpu_to_le32(get_seconds());
299 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
300 	es->s_last_error_line = cpu_to_le32(line);
301 	if (!es->s_first_error_time) {
302 		es->s_first_error_time = es->s_last_error_time;
303 		strncpy(es->s_first_error_func, func,
304 			sizeof(es->s_first_error_func));
305 		es->s_first_error_line = cpu_to_le32(line);
306 		es->s_first_error_ino = es->s_last_error_ino;
307 		es->s_first_error_block = es->s_last_error_block;
308 	}
309 	/*
310 	 * Start the daily error reporting function if it hasn't been
311 	 * started already
312 	 */
313 	if (!es->s_error_count)
314 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
315 	le32_add_cpu(&es->s_error_count, 1);
316 }
317 
318 static void save_error_info(struct super_block *sb, const char *func,
319 			    unsigned int line)
320 {
321 	__save_error_info(sb, func, line);
322 	ext4_commit_super(sb, 1);
323 }
324 
325 /*
326  * The del_gendisk() function uninitializes the disk-specific data
327  * structures, including the bdi structure, without telling anyone
328  * else.  Once this happens, any attempt to call mark_buffer_dirty()
329  * (for example, by ext4_commit_super), will cause a kernel OOPS.
330  * This is a kludge to prevent these oops until we can put in a proper
331  * hook in del_gendisk() to inform the VFS and file system layers.
332  */
333 static int block_device_ejected(struct super_block *sb)
334 {
335 	struct inode *bd_inode = sb->s_bdev->bd_inode;
336 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
337 
338 	return bdi->dev == NULL;
339 }
340 
341 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
342 {
343 	struct super_block		*sb = journal->j_private;
344 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
345 	int				error = is_journal_aborted(journal);
346 	struct ext4_journal_cb_entry	*jce;
347 
348 	BUG_ON(txn->t_state == T_FINISHED);
349 	spin_lock(&sbi->s_md_lock);
350 	while (!list_empty(&txn->t_private_list)) {
351 		jce = list_entry(txn->t_private_list.next,
352 				 struct ext4_journal_cb_entry, jce_list);
353 		list_del_init(&jce->jce_list);
354 		spin_unlock(&sbi->s_md_lock);
355 		jce->jce_func(sb, jce, error);
356 		spin_lock(&sbi->s_md_lock);
357 	}
358 	spin_unlock(&sbi->s_md_lock);
359 }
360 
361 /* Deal with the reporting of failure conditions on a filesystem such as
362  * inconsistencies detected or read IO failures.
363  *
364  * On ext2, we can store the error state of the filesystem in the
365  * superblock.  That is not possible on ext4, because we may have other
366  * write ordering constraints on the superblock which prevent us from
367  * writing it out straight away; and given that the journal is about to
368  * be aborted, we can't rely on the current, or future, transactions to
369  * write out the superblock safely.
370  *
371  * We'll just use the jbd2_journal_abort() error code to record an error in
372  * the journal instead.  On recovery, the journal will complain about
373  * that error until we've noted it down and cleared it.
374  */
375 
376 static void ext4_handle_error(struct super_block *sb)
377 {
378 	if (sb->s_flags & MS_RDONLY)
379 		return;
380 
381 	if (!test_opt(sb, ERRORS_CONT)) {
382 		journal_t *journal = EXT4_SB(sb)->s_journal;
383 
384 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
385 		if (journal)
386 			jbd2_journal_abort(journal, -EIO);
387 	}
388 	if (test_opt(sb, ERRORS_RO)) {
389 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
390 		/*
391 		 * Make sure updated value of ->s_mount_flags will be visible
392 		 * before ->s_flags update
393 		 */
394 		smp_wmb();
395 		sb->s_flags |= MS_RDONLY;
396 	}
397 	if (test_opt(sb, ERRORS_PANIC))
398 		panic("EXT4-fs (device %s): panic forced after error\n",
399 			sb->s_id);
400 }
401 
402 #define ext4_error_ratelimit(sb)					\
403 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
404 			     "EXT4-fs error")
405 
406 void __ext4_error(struct super_block *sb, const char *function,
407 		  unsigned int line, const char *fmt, ...)
408 {
409 	struct va_format vaf;
410 	va_list args;
411 
412 	if (ext4_error_ratelimit(sb)) {
413 		va_start(args, fmt);
414 		vaf.fmt = fmt;
415 		vaf.va = &args;
416 		printk(KERN_CRIT
417 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
418 		       sb->s_id, function, line, current->comm, &vaf);
419 		va_end(args);
420 	}
421 	save_error_info(sb, function, line);
422 	ext4_handle_error(sb);
423 }
424 
425 void __ext4_error_inode(struct inode *inode, const char *function,
426 			unsigned int line, ext4_fsblk_t block,
427 			const char *fmt, ...)
428 {
429 	va_list args;
430 	struct va_format vaf;
431 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
432 
433 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
434 	es->s_last_error_block = cpu_to_le64(block);
435 	if (ext4_error_ratelimit(inode->i_sb)) {
436 		va_start(args, fmt);
437 		vaf.fmt = fmt;
438 		vaf.va = &args;
439 		if (block)
440 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
441 			       "inode #%lu: block %llu: comm %s: %pV\n",
442 			       inode->i_sb->s_id, function, line, inode->i_ino,
443 			       block, current->comm, &vaf);
444 		else
445 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
446 			       "inode #%lu: comm %s: %pV\n",
447 			       inode->i_sb->s_id, function, line, inode->i_ino,
448 			       current->comm, &vaf);
449 		va_end(args);
450 	}
451 	save_error_info(inode->i_sb, function, line);
452 	ext4_handle_error(inode->i_sb);
453 }
454 
455 void __ext4_error_file(struct file *file, const char *function,
456 		       unsigned int line, ext4_fsblk_t block,
457 		       const char *fmt, ...)
458 {
459 	va_list args;
460 	struct va_format vaf;
461 	struct ext4_super_block *es;
462 	struct inode *inode = file_inode(file);
463 	char pathname[80], *path;
464 
465 	es = EXT4_SB(inode->i_sb)->s_es;
466 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
467 	if (ext4_error_ratelimit(inode->i_sb)) {
468 		path = file_path(file, pathname, sizeof(pathname));
469 		if (IS_ERR(path))
470 			path = "(unknown)";
471 		va_start(args, fmt);
472 		vaf.fmt = fmt;
473 		vaf.va = &args;
474 		if (block)
475 			printk(KERN_CRIT
476 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
477 			       "block %llu: comm %s: path %s: %pV\n",
478 			       inode->i_sb->s_id, function, line, inode->i_ino,
479 			       block, current->comm, path, &vaf);
480 		else
481 			printk(KERN_CRIT
482 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
483 			       "comm %s: path %s: %pV\n",
484 			       inode->i_sb->s_id, function, line, inode->i_ino,
485 			       current->comm, path, &vaf);
486 		va_end(args);
487 	}
488 	save_error_info(inode->i_sb, function, line);
489 	ext4_handle_error(inode->i_sb);
490 }
491 
492 const char *ext4_decode_error(struct super_block *sb, int errno,
493 			      char nbuf[16])
494 {
495 	char *errstr = NULL;
496 
497 	switch (errno) {
498 	case -EIO:
499 		errstr = "IO failure";
500 		break;
501 	case -ENOMEM:
502 		errstr = "Out of memory";
503 		break;
504 	case -EROFS:
505 		if (!sb || (EXT4_SB(sb)->s_journal &&
506 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
507 			errstr = "Journal has aborted";
508 		else
509 			errstr = "Readonly filesystem";
510 		break;
511 	default:
512 		/* If the caller passed in an extra buffer for unknown
513 		 * errors, textualise them now.  Else we just return
514 		 * NULL. */
515 		if (nbuf) {
516 			/* Check for truncated error codes... */
517 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
518 				errstr = nbuf;
519 		}
520 		break;
521 	}
522 
523 	return errstr;
524 }
525 
526 /* __ext4_std_error decodes expected errors from journaling functions
527  * automatically and invokes the appropriate error response.  */
528 
529 void __ext4_std_error(struct super_block *sb, const char *function,
530 		      unsigned int line, int errno)
531 {
532 	char nbuf[16];
533 	const char *errstr;
534 
535 	/* Special case: if the error is EROFS, and we're not already
536 	 * inside a transaction, then there's really no point in logging
537 	 * an error. */
538 	if (errno == -EROFS && journal_current_handle() == NULL &&
539 	    (sb->s_flags & MS_RDONLY))
540 		return;
541 
542 	if (ext4_error_ratelimit(sb)) {
543 		errstr = ext4_decode_error(sb, errno, nbuf);
544 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
545 		       sb->s_id, function, line, errstr);
546 	}
547 
548 	save_error_info(sb, function, line);
549 	ext4_handle_error(sb);
550 }
551 
552 /*
553  * ext4_abort is a much stronger failure handler than ext4_error.  The
554  * abort function may be used to deal with unrecoverable failures such
555  * as journal IO errors or ENOMEM at a critical moment in log management.
556  *
557  * We unconditionally force the filesystem into an ABORT|READONLY state,
558  * unless the error response on the fs has been set to panic in which
559  * case we take the easy way out and panic immediately.
560  */
561 
562 void __ext4_abort(struct super_block *sb, const char *function,
563 		unsigned int line, const char *fmt, ...)
564 {
565 	va_list args;
566 
567 	save_error_info(sb, function, line);
568 	va_start(args, fmt);
569 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
570 	       function, line);
571 	vprintk(fmt, args);
572 	printk("\n");
573 	va_end(args);
574 
575 	if ((sb->s_flags & MS_RDONLY) == 0) {
576 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
577 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
578 		/*
579 		 * Make sure updated value of ->s_mount_flags will be visible
580 		 * before ->s_flags update
581 		 */
582 		smp_wmb();
583 		sb->s_flags |= MS_RDONLY;
584 		if (EXT4_SB(sb)->s_journal)
585 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
586 		save_error_info(sb, function, line);
587 	}
588 	if (test_opt(sb, ERRORS_PANIC))
589 		panic("EXT4-fs panic from previous error\n");
590 }
591 
592 void __ext4_msg(struct super_block *sb,
593 		const char *prefix, const char *fmt, ...)
594 {
595 	struct va_format vaf;
596 	va_list args;
597 
598 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
599 		return;
600 
601 	va_start(args, fmt);
602 	vaf.fmt = fmt;
603 	vaf.va = &args;
604 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
605 	va_end(args);
606 }
607 
608 #define ext4_warning_ratelimit(sb)					\
609 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
610 			     "EXT4-fs warning")
611 
612 void __ext4_warning(struct super_block *sb, const char *function,
613 		    unsigned int line, const char *fmt, ...)
614 {
615 	struct va_format vaf;
616 	va_list args;
617 
618 	if (!ext4_warning_ratelimit(sb))
619 		return;
620 
621 	va_start(args, fmt);
622 	vaf.fmt = fmt;
623 	vaf.va = &args;
624 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
625 	       sb->s_id, function, line, &vaf);
626 	va_end(args);
627 }
628 
629 void __ext4_warning_inode(const struct inode *inode, const char *function,
630 			  unsigned int line, const char *fmt, ...)
631 {
632 	struct va_format vaf;
633 	va_list args;
634 
635 	if (!ext4_warning_ratelimit(inode->i_sb))
636 		return;
637 
638 	va_start(args, fmt);
639 	vaf.fmt = fmt;
640 	vaf.va = &args;
641 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
642 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
643 	       function, line, inode->i_ino, current->comm, &vaf);
644 	va_end(args);
645 }
646 
647 void __ext4_grp_locked_error(const char *function, unsigned int line,
648 			     struct super_block *sb, ext4_group_t grp,
649 			     unsigned long ino, ext4_fsblk_t block,
650 			     const char *fmt, ...)
651 __releases(bitlock)
652 __acquires(bitlock)
653 {
654 	struct va_format vaf;
655 	va_list args;
656 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
657 
658 	es->s_last_error_ino = cpu_to_le32(ino);
659 	es->s_last_error_block = cpu_to_le64(block);
660 	__save_error_info(sb, function, line);
661 
662 	if (ext4_error_ratelimit(sb)) {
663 		va_start(args, fmt);
664 		vaf.fmt = fmt;
665 		vaf.va = &args;
666 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
667 		       sb->s_id, function, line, grp);
668 		if (ino)
669 			printk(KERN_CONT "inode %lu: ", ino);
670 		if (block)
671 			printk(KERN_CONT "block %llu:",
672 			       (unsigned long long) block);
673 		printk(KERN_CONT "%pV\n", &vaf);
674 		va_end(args);
675 	}
676 
677 	if (test_opt(sb, ERRORS_CONT)) {
678 		ext4_commit_super(sb, 0);
679 		return;
680 	}
681 
682 	ext4_unlock_group(sb, grp);
683 	ext4_handle_error(sb);
684 	/*
685 	 * We only get here in the ERRORS_RO case; relocking the group
686 	 * may be dangerous, but nothing bad will happen since the
687 	 * filesystem will have already been marked read/only and the
688 	 * journal has been aborted.  We return 1 as a hint to callers
689 	 * who might what to use the return value from
690 	 * ext4_grp_locked_error() to distinguish between the
691 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
692 	 * aggressively from the ext4 function in question, with a
693 	 * more appropriate error code.
694 	 */
695 	ext4_lock_group(sb, grp);
696 	return;
697 }
698 
699 void ext4_update_dynamic_rev(struct super_block *sb)
700 {
701 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
702 
703 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
704 		return;
705 
706 	ext4_warning(sb,
707 		     "updating to rev %d because of new feature flag, "
708 		     "running e2fsck is recommended",
709 		     EXT4_DYNAMIC_REV);
710 
711 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
712 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
713 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
714 	/* leave es->s_feature_*compat flags alone */
715 	/* es->s_uuid will be set by e2fsck if empty */
716 
717 	/*
718 	 * The rest of the superblock fields should be zero, and if not it
719 	 * means they are likely already in use, so leave them alone.  We
720 	 * can leave it up to e2fsck to clean up any inconsistencies there.
721 	 */
722 }
723 
724 /*
725  * Open the external journal device
726  */
727 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
728 {
729 	struct block_device *bdev;
730 	char b[BDEVNAME_SIZE];
731 
732 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
733 	if (IS_ERR(bdev))
734 		goto fail;
735 	return bdev;
736 
737 fail:
738 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
739 			__bdevname(dev, b), PTR_ERR(bdev));
740 	return NULL;
741 }
742 
743 /*
744  * Release the journal device
745  */
746 static void ext4_blkdev_put(struct block_device *bdev)
747 {
748 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
749 }
750 
751 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
752 {
753 	struct block_device *bdev;
754 	bdev = sbi->journal_bdev;
755 	if (bdev) {
756 		ext4_blkdev_put(bdev);
757 		sbi->journal_bdev = NULL;
758 	}
759 }
760 
761 static inline struct inode *orphan_list_entry(struct list_head *l)
762 {
763 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
764 }
765 
766 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
767 {
768 	struct list_head *l;
769 
770 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
771 		 le32_to_cpu(sbi->s_es->s_last_orphan));
772 
773 	printk(KERN_ERR "sb_info orphan list:\n");
774 	list_for_each(l, &sbi->s_orphan) {
775 		struct inode *inode = orphan_list_entry(l);
776 		printk(KERN_ERR "  "
777 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
778 		       inode->i_sb->s_id, inode->i_ino, inode,
779 		       inode->i_mode, inode->i_nlink,
780 		       NEXT_ORPHAN(inode));
781 	}
782 }
783 
784 static void ext4_put_super(struct super_block *sb)
785 {
786 	struct ext4_sb_info *sbi = EXT4_SB(sb);
787 	struct ext4_super_block *es = sbi->s_es;
788 	int i, err;
789 
790 	ext4_unregister_li_request(sb);
791 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
792 
793 	flush_workqueue(sbi->rsv_conversion_wq);
794 	destroy_workqueue(sbi->rsv_conversion_wq);
795 
796 	if (sbi->s_journal) {
797 		err = jbd2_journal_destroy(sbi->s_journal);
798 		sbi->s_journal = NULL;
799 		if (err < 0)
800 			ext4_abort(sb, "Couldn't clean up the journal");
801 	}
802 
803 	ext4_es_unregister_shrinker(sbi);
804 	del_timer_sync(&sbi->s_err_report);
805 	ext4_release_system_zone(sb);
806 	ext4_mb_release(sb);
807 	ext4_ext_release(sb);
808 	ext4_xattr_put_super(sb);
809 
810 	if (!(sb->s_flags & MS_RDONLY)) {
811 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
812 		es->s_state = cpu_to_le16(sbi->s_mount_state);
813 	}
814 	if (!(sb->s_flags & MS_RDONLY))
815 		ext4_commit_super(sb, 1);
816 
817 	if (sbi->s_proc) {
818 		remove_proc_entry("options", sbi->s_proc);
819 		remove_proc_entry(sb->s_id, ext4_proc_root);
820 	}
821 	kobject_del(&sbi->s_kobj);
822 
823 	for (i = 0; i < sbi->s_gdb_count; i++)
824 		brelse(sbi->s_group_desc[i]);
825 	kvfree(sbi->s_group_desc);
826 	kvfree(sbi->s_flex_groups);
827 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
828 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
829 	percpu_counter_destroy(&sbi->s_dirs_counter);
830 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
831 	brelse(sbi->s_sbh);
832 #ifdef CONFIG_QUOTA
833 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
834 		kfree(sbi->s_qf_names[i]);
835 #endif
836 
837 	/* Debugging code just in case the in-memory inode orphan list
838 	 * isn't empty.  The on-disk one can be non-empty if we've
839 	 * detected an error and taken the fs readonly, but the
840 	 * in-memory list had better be clean by this point. */
841 	if (!list_empty(&sbi->s_orphan))
842 		dump_orphan_list(sb, sbi);
843 	J_ASSERT(list_empty(&sbi->s_orphan));
844 
845 	sync_blockdev(sb->s_bdev);
846 	invalidate_bdev(sb->s_bdev);
847 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
848 		/*
849 		 * Invalidate the journal device's buffers.  We don't want them
850 		 * floating about in memory - the physical journal device may
851 		 * hotswapped, and it breaks the `ro-after' testing code.
852 		 */
853 		sync_blockdev(sbi->journal_bdev);
854 		invalidate_bdev(sbi->journal_bdev);
855 		ext4_blkdev_remove(sbi);
856 	}
857 	if (sbi->s_mb_cache) {
858 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
859 		sbi->s_mb_cache = NULL;
860 	}
861 	if (sbi->s_mmp_tsk)
862 		kthread_stop(sbi->s_mmp_tsk);
863 	sb->s_fs_info = NULL;
864 	/*
865 	 * Now that we are completely done shutting down the
866 	 * superblock, we need to actually destroy the kobject.
867 	 */
868 	kobject_put(&sbi->s_kobj);
869 	wait_for_completion(&sbi->s_kobj_unregister);
870 	if (sbi->s_chksum_driver)
871 		crypto_free_shash(sbi->s_chksum_driver);
872 	kfree(sbi->s_blockgroup_lock);
873 	kfree(sbi);
874 }
875 
876 static struct kmem_cache *ext4_inode_cachep;
877 
878 /*
879  * Called inside transaction, so use GFP_NOFS
880  */
881 static struct inode *ext4_alloc_inode(struct super_block *sb)
882 {
883 	struct ext4_inode_info *ei;
884 
885 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
886 	if (!ei)
887 		return NULL;
888 
889 	ei->vfs_inode.i_version = 1;
890 	spin_lock_init(&ei->i_raw_lock);
891 	INIT_LIST_HEAD(&ei->i_prealloc_list);
892 	spin_lock_init(&ei->i_prealloc_lock);
893 	ext4_es_init_tree(&ei->i_es_tree);
894 	rwlock_init(&ei->i_es_lock);
895 	INIT_LIST_HEAD(&ei->i_es_list);
896 	ei->i_es_all_nr = 0;
897 	ei->i_es_shk_nr = 0;
898 	ei->i_es_shrink_lblk = 0;
899 	ei->i_reserved_data_blocks = 0;
900 	ei->i_reserved_meta_blocks = 0;
901 	ei->i_allocated_meta_blocks = 0;
902 	ei->i_da_metadata_calc_len = 0;
903 	ei->i_da_metadata_calc_last_lblock = 0;
904 	spin_lock_init(&(ei->i_block_reservation_lock));
905 #ifdef CONFIG_QUOTA
906 	ei->i_reserved_quota = 0;
907 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
908 #endif
909 	ei->jinode = NULL;
910 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
911 	spin_lock_init(&ei->i_completed_io_lock);
912 	ei->i_sync_tid = 0;
913 	ei->i_datasync_tid = 0;
914 	atomic_set(&ei->i_ioend_count, 0);
915 	atomic_set(&ei->i_unwritten, 0);
916 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
917 #ifdef CONFIG_EXT4_FS_ENCRYPTION
918 	ei->i_crypt_info = NULL;
919 #endif
920 	return &ei->vfs_inode;
921 }
922 
923 static int ext4_drop_inode(struct inode *inode)
924 {
925 	int drop = generic_drop_inode(inode);
926 
927 	trace_ext4_drop_inode(inode, drop);
928 	return drop;
929 }
930 
931 static void ext4_i_callback(struct rcu_head *head)
932 {
933 	struct inode *inode = container_of(head, struct inode, i_rcu);
934 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
935 }
936 
937 static void ext4_destroy_inode(struct inode *inode)
938 {
939 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
940 		ext4_msg(inode->i_sb, KERN_ERR,
941 			 "Inode %lu (%p): orphan list check failed!",
942 			 inode->i_ino, EXT4_I(inode));
943 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
944 				EXT4_I(inode), sizeof(struct ext4_inode_info),
945 				true);
946 		dump_stack();
947 	}
948 	call_rcu(&inode->i_rcu, ext4_i_callback);
949 }
950 
951 static void init_once(void *foo)
952 {
953 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
954 
955 	INIT_LIST_HEAD(&ei->i_orphan);
956 	init_rwsem(&ei->xattr_sem);
957 	init_rwsem(&ei->i_data_sem);
958 	inode_init_once(&ei->vfs_inode);
959 }
960 
961 static int __init init_inodecache(void)
962 {
963 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
964 					     sizeof(struct ext4_inode_info),
965 					     0, (SLAB_RECLAIM_ACCOUNT|
966 						SLAB_MEM_SPREAD),
967 					     init_once);
968 	if (ext4_inode_cachep == NULL)
969 		return -ENOMEM;
970 	return 0;
971 }
972 
973 static void destroy_inodecache(void)
974 {
975 	/*
976 	 * Make sure all delayed rcu free inodes are flushed before we
977 	 * destroy cache.
978 	 */
979 	rcu_barrier();
980 	kmem_cache_destroy(ext4_inode_cachep);
981 }
982 
983 void ext4_clear_inode(struct inode *inode)
984 {
985 	invalidate_inode_buffers(inode);
986 	clear_inode(inode);
987 	dquot_drop(inode);
988 	ext4_discard_preallocations(inode);
989 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
990 	if (EXT4_I(inode)->jinode) {
991 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
992 					       EXT4_I(inode)->jinode);
993 		jbd2_free_inode(EXT4_I(inode)->jinode);
994 		EXT4_I(inode)->jinode = NULL;
995 	}
996 #ifdef CONFIG_EXT4_FS_ENCRYPTION
997 	if (EXT4_I(inode)->i_crypt_info)
998 		ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info);
999 #endif
1000 }
1001 
1002 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1003 					u64 ino, u32 generation)
1004 {
1005 	struct inode *inode;
1006 
1007 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1008 		return ERR_PTR(-ESTALE);
1009 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1010 		return ERR_PTR(-ESTALE);
1011 
1012 	/* iget isn't really right if the inode is currently unallocated!!
1013 	 *
1014 	 * ext4_read_inode will return a bad_inode if the inode had been
1015 	 * deleted, so we should be safe.
1016 	 *
1017 	 * Currently we don't know the generation for parent directory, so
1018 	 * a generation of 0 means "accept any"
1019 	 */
1020 	inode = ext4_iget_normal(sb, ino);
1021 	if (IS_ERR(inode))
1022 		return ERR_CAST(inode);
1023 	if (generation && inode->i_generation != generation) {
1024 		iput(inode);
1025 		return ERR_PTR(-ESTALE);
1026 	}
1027 
1028 	return inode;
1029 }
1030 
1031 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1032 					int fh_len, int fh_type)
1033 {
1034 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1035 				    ext4_nfs_get_inode);
1036 }
1037 
1038 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1039 					int fh_len, int fh_type)
1040 {
1041 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1042 				    ext4_nfs_get_inode);
1043 }
1044 
1045 /*
1046  * Try to release metadata pages (indirect blocks, directories) which are
1047  * mapped via the block device.  Since these pages could have journal heads
1048  * which would prevent try_to_free_buffers() from freeing them, we must use
1049  * jbd2 layer's try_to_free_buffers() function to release them.
1050  */
1051 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1052 				 gfp_t wait)
1053 {
1054 	journal_t *journal = EXT4_SB(sb)->s_journal;
1055 
1056 	WARN_ON(PageChecked(page));
1057 	if (!page_has_buffers(page))
1058 		return 0;
1059 	if (journal)
1060 		return jbd2_journal_try_to_free_buffers(journal, page,
1061 							wait & ~__GFP_WAIT);
1062 	return try_to_free_buffers(page);
1063 }
1064 
1065 #ifdef CONFIG_QUOTA
1066 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1067 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1068 
1069 static int ext4_write_dquot(struct dquot *dquot);
1070 static int ext4_acquire_dquot(struct dquot *dquot);
1071 static int ext4_release_dquot(struct dquot *dquot);
1072 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1073 static int ext4_write_info(struct super_block *sb, int type);
1074 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1075 			 struct path *path);
1076 static int ext4_quota_off(struct super_block *sb, int type);
1077 static int ext4_quota_on_mount(struct super_block *sb, int type);
1078 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1079 			       size_t len, loff_t off);
1080 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1081 				const char *data, size_t len, loff_t off);
1082 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1083 			     unsigned int flags);
1084 static int ext4_enable_quotas(struct super_block *sb);
1085 
1086 static struct dquot **ext4_get_dquots(struct inode *inode)
1087 {
1088 	return EXT4_I(inode)->i_dquot;
1089 }
1090 
1091 static const struct dquot_operations ext4_quota_operations = {
1092 	.get_reserved_space = ext4_get_reserved_space,
1093 	.write_dquot	= ext4_write_dquot,
1094 	.acquire_dquot	= ext4_acquire_dquot,
1095 	.release_dquot	= ext4_release_dquot,
1096 	.mark_dirty	= ext4_mark_dquot_dirty,
1097 	.write_info	= ext4_write_info,
1098 	.alloc_dquot	= dquot_alloc,
1099 	.destroy_dquot	= dquot_destroy,
1100 };
1101 
1102 static const struct quotactl_ops ext4_qctl_operations = {
1103 	.quota_on	= ext4_quota_on,
1104 	.quota_off	= ext4_quota_off,
1105 	.quota_sync	= dquot_quota_sync,
1106 	.get_state	= dquot_get_state,
1107 	.set_info	= dquot_set_dqinfo,
1108 	.get_dqblk	= dquot_get_dqblk,
1109 	.set_dqblk	= dquot_set_dqblk
1110 };
1111 #endif
1112 
1113 static const struct super_operations ext4_sops = {
1114 	.alloc_inode	= ext4_alloc_inode,
1115 	.destroy_inode	= ext4_destroy_inode,
1116 	.write_inode	= ext4_write_inode,
1117 	.dirty_inode	= ext4_dirty_inode,
1118 	.drop_inode	= ext4_drop_inode,
1119 	.evict_inode	= ext4_evict_inode,
1120 	.put_super	= ext4_put_super,
1121 	.sync_fs	= ext4_sync_fs,
1122 	.freeze_fs	= ext4_freeze,
1123 	.unfreeze_fs	= ext4_unfreeze,
1124 	.statfs		= ext4_statfs,
1125 	.remount_fs	= ext4_remount,
1126 	.show_options	= ext4_show_options,
1127 #ifdef CONFIG_QUOTA
1128 	.quota_read	= ext4_quota_read,
1129 	.quota_write	= ext4_quota_write,
1130 	.get_dquots	= ext4_get_dquots,
1131 #endif
1132 	.bdev_try_to_free_page = bdev_try_to_free_page,
1133 };
1134 
1135 static const struct export_operations ext4_export_ops = {
1136 	.fh_to_dentry = ext4_fh_to_dentry,
1137 	.fh_to_parent = ext4_fh_to_parent,
1138 	.get_parent = ext4_get_parent,
1139 };
1140 
1141 enum {
1142 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1143 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1144 	Opt_nouid32, Opt_debug, Opt_removed,
1145 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1146 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1147 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1148 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1149 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1150 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1151 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1152 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1153 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1154 	Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
1155 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1156 	Opt_lazytime, Opt_nolazytime,
1157 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1158 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1159 	Opt_dioread_nolock, Opt_dioread_lock,
1160 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1161 	Opt_max_dir_size_kb, Opt_nojournal_checksum,
1162 };
1163 
1164 static const match_table_t tokens = {
1165 	{Opt_bsd_df, "bsddf"},
1166 	{Opt_minix_df, "minixdf"},
1167 	{Opt_grpid, "grpid"},
1168 	{Opt_grpid, "bsdgroups"},
1169 	{Opt_nogrpid, "nogrpid"},
1170 	{Opt_nogrpid, "sysvgroups"},
1171 	{Opt_resgid, "resgid=%u"},
1172 	{Opt_resuid, "resuid=%u"},
1173 	{Opt_sb, "sb=%u"},
1174 	{Opt_err_cont, "errors=continue"},
1175 	{Opt_err_panic, "errors=panic"},
1176 	{Opt_err_ro, "errors=remount-ro"},
1177 	{Opt_nouid32, "nouid32"},
1178 	{Opt_debug, "debug"},
1179 	{Opt_removed, "oldalloc"},
1180 	{Opt_removed, "orlov"},
1181 	{Opt_user_xattr, "user_xattr"},
1182 	{Opt_nouser_xattr, "nouser_xattr"},
1183 	{Opt_acl, "acl"},
1184 	{Opt_noacl, "noacl"},
1185 	{Opt_noload, "norecovery"},
1186 	{Opt_noload, "noload"},
1187 	{Opt_removed, "nobh"},
1188 	{Opt_removed, "bh"},
1189 	{Opt_commit, "commit=%u"},
1190 	{Opt_min_batch_time, "min_batch_time=%u"},
1191 	{Opt_max_batch_time, "max_batch_time=%u"},
1192 	{Opt_journal_dev, "journal_dev=%u"},
1193 	{Opt_journal_path, "journal_path=%s"},
1194 	{Opt_journal_checksum, "journal_checksum"},
1195 	{Opt_nojournal_checksum, "nojournal_checksum"},
1196 	{Opt_journal_async_commit, "journal_async_commit"},
1197 	{Opt_abort, "abort"},
1198 	{Opt_data_journal, "data=journal"},
1199 	{Opt_data_ordered, "data=ordered"},
1200 	{Opt_data_writeback, "data=writeback"},
1201 	{Opt_data_err_abort, "data_err=abort"},
1202 	{Opt_data_err_ignore, "data_err=ignore"},
1203 	{Opt_offusrjquota, "usrjquota="},
1204 	{Opt_usrjquota, "usrjquota=%s"},
1205 	{Opt_offgrpjquota, "grpjquota="},
1206 	{Opt_grpjquota, "grpjquota=%s"},
1207 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1208 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1209 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1210 	{Opt_grpquota, "grpquota"},
1211 	{Opt_noquota, "noquota"},
1212 	{Opt_quota, "quota"},
1213 	{Opt_usrquota, "usrquota"},
1214 	{Opt_barrier, "barrier=%u"},
1215 	{Opt_barrier, "barrier"},
1216 	{Opt_nobarrier, "nobarrier"},
1217 	{Opt_i_version, "i_version"},
1218 	{Opt_dax, "dax"},
1219 	{Opt_stripe, "stripe=%u"},
1220 	{Opt_delalloc, "delalloc"},
1221 	{Opt_lazytime, "lazytime"},
1222 	{Opt_nolazytime, "nolazytime"},
1223 	{Opt_nodelalloc, "nodelalloc"},
1224 	{Opt_removed, "mblk_io_submit"},
1225 	{Opt_removed, "nomblk_io_submit"},
1226 	{Opt_block_validity, "block_validity"},
1227 	{Opt_noblock_validity, "noblock_validity"},
1228 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1229 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1230 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1231 	{Opt_auto_da_alloc, "auto_da_alloc"},
1232 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1233 	{Opt_dioread_nolock, "dioread_nolock"},
1234 	{Opt_dioread_lock, "dioread_lock"},
1235 	{Opt_discard, "discard"},
1236 	{Opt_nodiscard, "nodiscard"},
1237 	{Opt_init_itable, "init_itable=%u"},
1238 	{Opt_init_itable, "init_itable"},
1239 	{Opt_noinit_itable, "noinit_itable"},
1240 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1241 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1242 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1243 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1244 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1245 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1246 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1247 	{Opt_err, NULL},
1248 };
1249 
1250 static ext4_fsblk_t get_sb_block(void **data)
1251 {
1252 	ext4_fsblk_t	sb_block;
1253 	char		*options = (char *) *data;
1254 
1255 	if (!options || strncmp(options, "sb=", 3) != 0)
1256 		return 1;	/* Default location */
1257 
1258 	options += 3;
1259 	/* TODO: use simple_strtoll with >32bit ext4 */
1260 	sb_block = simple_strtoul(options, &options, 0);
1261 	if (*options && *options != ',') {
1262 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1263 		       (char *) *data);
1264 		return 1;
1265 	}
1266 	if (*options == ',')
1267 		options++;
1268 	*data = (void *) options;
1269 
1270 	return sb_block;
1271 }
1272 
1273 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1274 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1275 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1276 
1277 #ifdef CONFIG_QUOTA
1278 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1279 {
1280 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1281 	char *qname;
1282 	int ret = -1;
1283 
1284 	if (sb_any_quota_loaded(sb) &&
1285 		!sbi->s_qf_names[qtype]) {
1286 		ext4_msg(sb, KERN_ERR,
1287 			"Cannot change journaled "
1288 			"quota options when quota turned on");
1289 		return -1;
1290 	}
1291 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1292 		ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1293 			 "when QUOTA feature is enabled");
1294 		return -1;
1295 	}
1296 	qname = match_strdup(args);
1297 	if (!qname) {
1298 		ext4_msg(sb, KERN_ERR,
1299 			"Not enough memory for storing quotafile name");
1300 		return -1;
1301 	}
1302 	if (sbi->s_qf_names[qtype]) {
1303 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1304 			ret = 1;
1305 		else
1306 			ext4_msg(sb, KERN_ERR,
1307 				 "%s quota file already specified",
1308 				 QTYPE2NAME(qtype));
1309 		goto errout;
1310 	}
1311 	if (strchr(qname, '/')) {
1312 		ext4_msg(sb, KERN_ERR,
1313 			"quotafile must be on filesystem root");
1314 		goto errout;
1315 	}
1316 	sbi->s_qf_names[qtype] = qname;
1317 	set_opt(sb, QUOTA);
1318 	return 1;
1319 errout:
1320 	kfree(qname);
1321 	return ret;
1322 }
1323 
1324 static int clear_qf_name(struct super_block *sb, int qtype)
1325 {
1326 
1327 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1328 
1329 	if (sb_any_quota_loaded(sb) &&
1330 		sbi->s_qf_names[qtype]) {
1331 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1332 			" when quota turned on");
1333 		return -1;
1334 	}
1335 	kfree(sbi->s_qf_names[qtype]);
1336 	sbi->s_qf_names[qtype] = NULL;
1337 	return 1;
1338 }
1339 #endif
1340 
1341 #define MOPT_SET	0x0001
1342 #define MOPT_CLEAR	0x0002
1343 #define MOPT_NOSUPPORT	0x0004
1344 #define MOPT_EXPLICIT	0x0008
1345 #define MOPT_CLEAR_ERR	0x0010
1346 #define MOPT_GTE0	0x0020
1347 #ifdef CONFIG_QUOTA
1348 #define MOPT_Q		0
1349 #define MOPT_QFMT	0x0040
1350 #else
1351 #define MOPT_Q		MOPT_NOSUPPORT
1352 #define MOPT_QFMT	MOPT_NOSUPPORT
1353 #endif
1354 #define MOPT_DATAJ	0x0080
1355 #define MOPT_NO_EXT2	0x0100
1356 #define MOPT_NO_EXT3	0x0200
1357 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1358 #define MOPT_STRING	0x0400
1359 
1360 static const struct mount_opts {
1361 	int	token;
1362 	int	mount_opt;
1363 	int	flags;
1364 } ext4_mount_opts[] = {
1365 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1366 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1367 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1368 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1369 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1370 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1371 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1372 	 MOPT_EXT4_ONLY | MOPT_SET},
1373 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1374 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1375 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1376 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1377 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1378 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1379 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1380 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1381 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1382 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1383 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1384 	 MOPT_EXT4_ONLY | MOPT_SET},
1385 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1386 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1387 	 MOPT_EXT4_ONLY | MOPT_SET},
1388 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1389 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1390 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1391 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1392 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1393 	 MOPT_NO_EXT2 | MOPT_SET},
1394 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1395 	 MOPT_NO_EXT2 | MOPT_CLEAR},
1396 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1397 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1398 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1399 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1400 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1401 	{Opt_commit, 0, MOPT_GTE0},
1402 	{Opt_max_batch_time, 0, MOPT_GTE0},
1403 	{Opt_min_batch_time, 0, MOPT_GTE0},
1404 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1405 	{Opt_init_itable, 0, MOPT_GTE0},
1406 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1407 	{Opt_stripe, 0, MOPT_GTE0},
1408 	{Opt_resuid, 0, MOPT_GTE0},
1409 	{Opt_resgid, 0, MOPT_GTE0},
1410 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1411 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1412 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1413 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1414 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1415 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1416 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1417 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1418 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1419 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1420 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1421 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1422 #else
1423 	{Opt_acl, 0, MOPT_NOSUPPORT},
1424 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1425 #endif
1426 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1427 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1428 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1429 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1430 							MOPT_SET | MOPT_Q},
1431 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1432 							MOPT_SET | MOPT_Q},
1433 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1434 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1435 	{Opt_usrjquota, 0, MOPT_Q},
1436 	{Opt_grpjquota, 0, MOPT_Q},
1437 	{Opt_offusrjquota, 0, MOPT_Q},
1438 	{Opt_offgrpjquota, 0, MOPT_Q},
1439 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1440 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1441 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1442 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1443 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1444 	{Opt_err, 0, 0}
1445 };
1446 
1447 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1448 			    substring_t *args, unsigned long *journal_devnum,
1449 			    unsigned int *journal_ioprio, int is_remount)
1450 {
1451 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1452 	const struct mount_opts *m;
1453 	kuid_t uid;
1454 	kgid_t gid;
1455 	int arg = 0;
1456 
1457 #ifdef CONFIG_QUOTA
1458 	if (token == Opt_usrjquota)
1459 		return set_qf_name(sb, USRQUOTA, &args[0]);
1460 	else if (token == Opt_grpjquota)
1461 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1462 	else if (token == Opt_offusrjquota)
1463 		return clear_qf_name(sb, USRQUOTA);
1464 	else if (token == Opt_offgrpjquota)
1465 		return clear_qf_name(sb, GRPQUOTA);
1466 #endif
1467 	switch (token) {
1468 	case Opt_noacl:
1469 	case Opt_nouser_xattr:
1470 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1471 		break;
1472 	case Opt_sb:
1473 		return 1;	/* handled by get_sb_block() */
1474 	case Opt_removed:
1475 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1476 		return 1;
1477 	case Opt_abort:
1478 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1479 		return 1;
1480 	case Opt_i_version:
1481 		sb->s_flags |= MS_I_VERSION;
1482 		return 1;
1483 	case Opt_lazytime:
1484 		sb->s_flags |= MS_LAZYTIME;
1485 		return 1;
1486 	case Opt_nolazytime:
1487 		sb->s_flags &= ~MS_LAZYTIME;
1488 		return 1;
1489 	}
1490 
1491 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1492 		if (token == m->token)
1493 			break;
1494 
1495 	if (m->token == Opt_err) {
1496 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1497 			 "or missing value", opt);
1498 		return -1;
1499 	}
1500 
1501 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1502 		ext4_msg(sb, KERN_ERR,
1503 			 "Mount option \"%s\" incompatible with ext2", opt);
1504 		return -1;
1505 	}
1506 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1507 		ext4_msg(sb, KERN_ERR,
1508 			 "Mount option \"%s\" incompatible with ext3", opt);
1509 		return -1;
1510 	}
1511 
1512 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1513 		return -1;
1514 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1515 		return -1;
1516 	if (m->flags & MOPT_EXPLICIT)
1517 		set_opt2(sb, EXPLICIT_DELALLOC);
1518 	if (m->flags & MOPT_CLEAR_ERR)
1519 		clear_opt(sb, ERRORS_MASK);
1520 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1521 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1522 			 "options when quota turned on");
1523 		return -1;
1524 	}
1525 
1526 	if (m->flags & MOPT_NOSUPPORT) {
1527 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1528 	} else if (token == Opt_commit) {
1529 		if (arg == 0)
1530 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1531 		sbi->s_commit_interval = HZ * arg;
1532 	} else if (token == Opt_max_batch_time) {
1533 		sbi->s_max_batch_time = arg;
1534 	} else if (token == Opt_min_batch_time) {
1535 		sbi->s_min_batch_time = arg;
1536 	} else if (token == Opt_inode_readahead_blks) {
1537 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1538 			ext4_msg(sb, KERN_ERR,
1539 				 "EXT4-fs: inode_readahead_blks must be "
1540 				 "0 or a power of 2 smaller than 2^31");
1541 			return -1;
1542 		}
1543 		sbi->s_inode_readahead_blks = arg;
1544 	} else if (token == Opt_init_itable) {
1545 		set_opt(sb, INIT_INODE_TABLE);
1546 		if (!args->from)
1547 			arg = EXT4_DEF_LI_WAIT_MULT;
1548 		sbi->s_li_wait_mult = arg;
1549 	} else if (token == Opt_max_dir_size_kb) {
1550 		sbi->s_max_dir_size_kb = arg;
1551 	} else if (token == Opt_stripe) {
1552 		sbi->s_stripe = arg;
1553 	} else if (token == Opt_resuid) {
1554 		uid = make_kuid(current_user_ns(), arg);
1555 		if (!uid_valid(uid)) {
1556 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1557 			return -1;
1558 		}
1559 		sbi->s_resuid = uid;
1560 	} else if (token == Opt_resgid) {
1561 		gid = make_kgid(current_user_ns(), arg);
1562 		if (!gid_valid(gid)) {
1563 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1564 			return -1;
1565 		}
1566 		sbi->s_resgid = gid;
1567 	} else if (token == Opt_journal_dev) {
1568 		if (is_remount) {
1569 			ext4_msg(sb, KERN_ERR,
1570 				 "Cannot specify journal on remount");
1571 			return -1;
1572 		}
1573 		*journal_devnum = arg;
1574 	} else if (token == Opt_journal_path) {
1575 		char *journal_path;
1576 		struct inode *journal_inode;
1577 		struct path path;
1578 		int error;
1579 
1580 		if (is_remount) {
1581 			ext4_msg(sb, KERN_ERR,
1582 				 "Cannot specify journal on remount");
1583 			return -1;
1584 		}
1585 		journal_path = match_strdup(&args[0]);
1586 		if (!journal_path) {
1587 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1588 				"journal device string");
1589 			return -1;
1590 		}
1591 
1592 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1593 		if (error) {
1594 			ext4_msg(sb, KERN_ERR, "error: could not find "
1595 				"journal device path: error %d", error);
1596 			kfree(journal_path);
1597 			return -1;
1598 		}
1599 
1600 		journal_inode = d_inode(path.dentry);
1601 		if (!S_ISBLK(journal_inode->i_mode)) {
1602 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1603 				"is not a block device", journal_path);
1604 			path_put(&path);
1605 			kfree(journal_path);
1606 			return -1;
1607 		}
1608 
1609 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1610 		path_put(&path);
1611 		kfree(journal_path);
1612 	} else if (token == Opt_journal_ioprio) {
1613 		if (arg > 7) {
1614 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1615 				 " (must be 0-7)");
1616 			return -1;
1617 		}
1618 		*journal_ioprio =
1619 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1620 	} else if (token == Opt_test_dummy_encryption) {
1621 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1622 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1623 		ext4_msg(sb, KERN_WARNING,
1624 			 "Test dummy encryption mode enabled");
1625 #else
1626 		ext4_msg(sb, KERN_WARNING,
1627 			 "Test dummy encryption mount option ignored");
1628 #endif
1629 	} else if (m->flags & MOPT_DATAJ) {
1630 		if (is_remount) {
1631 			if (!sbi->s_journal)
1632 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1633 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1634 				ext4_msg(sb, KERN_ERR,
1635 					 "Cannot change data mode on remount");
1636 				return -1;
1637 			}
1638 		} else {
1639 			clear_opt(sb, DATA_FLAGS);
1640 			sbi->s_mount_opt |= m->mount_opt;
1641 		}
1642 #ifdef CONFIG_QUOTA
1643 	} else if (m->flags & MOPT_QFMT) {
1644 		if (sb_any_quota_loaded(sb) &&
1645 		    sbi->s_jquota_fmt != m->mount_opt) {
1646 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1647 				 "quota options when quota turned on");
1648 			return -1;
1649 		}
1650 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1651 					       EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1652 			ext4_msg(sb, KERN_ERR,
1653 				 "Cannot set journaled quota options "
1654 				 "when QUOTA feature is enabled");
1655 			return -1;
1656 		}
1657 		sbi->s_jquota_fmt = m->mount_opt;
1658 #endif
1659 #ifndef CONFIG_FS_DAX
1660 	} else if (token == Opt_dax) {
1661 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1662 		return -1;
1663 #endif
1664 	} else {
1665 		if (!args->from)
1666 			arg = 1;
1667 		if (m->flags & MOPT_CLEAR)
1668 			arg = !arg;
1669 		else if (unlikely(!(m->flags & MOPT_SET))) {
1670 			ext4_msg(sb, KERN_WARNING,
1671 				 "buggy handling of option %s", opt);
1672 			WARN_ON(1);
1673 			return -1;
1674 		}
1675 		if (arg != 0)
1676 			sbi->s_mount_opt |= m->mount_opt;
1677 		else
1678 			sbi->s_mount_opt &= ~m->mount_opt;
1679 	}
1680 	return 1;
1681 }
1682 
1683 static int parse_options(char *options, struct super_block *sb,
1684 			 unsigned long *journal_devnum,
1685 			 unsigned int *journal_ioprio,
1686 			 int is_remount)
1687 {
1688 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1689 	char *p;
1690 	substring_t args[MAX_OPT_ARGS];
1691 	int token;
1692 
1693 	if (!options)
1694 		return 1;
1695 
1696 	while ((p = strsep(&options, ",")) != NULL) {
1697 		if (!*p)
1698 			continue;
1699 		/*
1700 		 * Initialize args struct so we know whether arg was
1701 		 * found; some options take optional arguments.
1702 		 */
1703 		args[0].to = args[0].from = NULL;
1704 		token = match_token(p, tokens, args);
1705 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1706 				     journal_ioprio, is_remount) < 0)
1707 			return 0;
1708 	}
1709 #ifdef CONFIG_QUOTA
1710 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1711 	    (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1712 		ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1713 			 "feature is enabled");
1714 		return 0;
1715 	}
1716 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1717 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1718 			clear_opt(sb, USRQUOTA);
1719 
1720 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1721 			clear_opt(sb, GRPQUOTA);
1722 
1723 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1724 			ext4_msg(sb, KERN_ERR, "old and new quota "
1725 					"format mixing");
1726 			return 0;
1727 		}
1728 
1729 		if (!sbi->s_jquota_fmt) {
1730 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1731 					"not specified");
1732 			return 0;
1733 		}
1734 	}
1735 #endif
1736 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1737 		int blocksize =
1738 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1739 
1740 		if (blocksize < PAGE_CACHE_SIZE) {
1741 			ext4_msg(sb, KERN_ERR, "can't mount with "
1742 				 "dioread_nolock if block size != PAGE_SIZE");
1743 			return 0;
1744 		}
1745 	}
1746 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
1747 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
1748 		ext4_msg(sb, KERN_ERR, "can't mount with journal_async_commit "
1749 			 "in data=ordered mode");
1750 		return 0;
1751 	}
1752 	return 1;
1753 }
1754 
1755 static inline void ext4_show_quota_options(struct seq_file *seq,
1756 					   struct super_block *sb)
1757 {
1758 #if defined(CONFIG_QUOTA)
1759 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1760 
1761 	if (sbi->s_jquota_fmt) {
1762 		char *fmtname = "";
1763 
1764 		switch (sbi->s_jquota_fmt) {
1765 		case QFMT_VFS_OLD:
1766 			fmtname = "vfsold";
1767 			break;
1768 		case QFMT_VFS_V0:
1769 			fmtname = "vfsv0";
1770 			break;
1771 		case QFMT_VFS_V1:
1772 			fmtname = "vfsv1";
1773 			break;
1774 		}
1775 		seq_printf(seq, ",jqfmt=%s", fmtname);
1776 	}
1777 
1778 	if (sbi->s_qf_names[USRQUOTA])
1779 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1780 
1781 	if (sbi->s_qf_names[GRPQUOTA])
1782 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1783 #endif
1784 }
1785 
1786 static const char *token2str(int token)
1787 {
1788 	const struct match_token *t;
1789 
1790 	for (t = tokens; t->token != Opt_err; t++)
1791 		if (t->token == token && !strchr(t->pattern, '='))
1792 			break;
1793 	return t->pattern;
1794 }
1795 
1796 /*
1797  * Show an option if
1798  *  - it's set to a non-default value OR
1799  *  - if the per-sb default is different from the global default
1800  */
1801 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1802 			      int nodefs)
1803 {
1804 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1805 	struct ext4_super_block *es = sbi->s_es;
1806 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1807 	const struct mount_opts *m;
1808 	char sep = nodefs ? '\n' : ',';
1809 
1810 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1811 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1812 
1813 	if (sbi->s_sb_block != 1)
1814 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1815 
1816 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1817 		int want_set = m->flags & MOPT_SET;
1818 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1819 		    (m->flags & MOPT_CLEAR_ERR))
1820 			continue;
1821 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1822 			continue; /* skip if same as the default */
1823 		if ((want_set &&
1824 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1825 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1826 			continue; /* select Opt_noFoo vs Opt_Foo */
1827 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1828 	}
1829 
1830 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1831 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1832 		SEQ_OPTS_PRINT("resuid=%u",
1833 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1834 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1835 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1836 		SEQ_OPTS_PRINT("resgid=%u",
1837 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1838 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1839 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1840 		SEQ_OPTS_PUTS("errors=remount-ro");
1841 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1842 		SEQ_OPTS_PUTS("errors=continue");
1843 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1844 		SEQ_OPTS_PUTS("errors=panic");
1845 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1846 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1847 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1848 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1849 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1850 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1851 	if (sb->s_flags & MS_I_VERSION)
1852 		SEQ_OPTS_PUTS("i_version");
1853 	if (nodefs || sbi->s_stripe)
1854 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1855 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1856 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1857 			SEQ_OPTS_PUTS("data=journal");
1858 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1859 			SEQ_OPTS_PUTS("data=ordered");
1860 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1861 			SEQ_OPTS_PUTS("data=writeback");
1862 	}
1863 	if (nodefs ||
1864 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1865 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1866 			       sbi->s_inode_readahead_blks);
1867 
1868 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1869 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1870 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1871 	if (nodefs || sbi->s_max_dir_size_kb)
1872 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1873 
1874 	ext4_show_quota_options(seq, sb);
1875 	return 0;
1876 }
1877 
1878 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1879 {
1880 	return _ext4_show_options(seq, root->d_sb, 0);
1881 }
1882 
1883 static int options_seq_show(struct seq_file *seq, void *offset)
1884 {
1885 	struct super_block *sb = seq->private;
1886 	int rc;
1887 
1888 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1889 	rc = _ext4_show_options(seq, sb, 1);
1890 	seq_puts(seq, "\n");
1891 	return rc;
1892 }
1893 
1894 static int options_open_fs(struct inode *inode, struct file *file)
1895 {
1896 	return single_open(file, options_seq_show, PDE_DATA(inode));
1897 }
1898 
1899 static const struct file_operations ext4_seq_options_fops = {
1900 	.owner = THIS_MODULE,
1901 	.open = options_open_fs,
1902 	.read = seq_read,
1903 	.llseek = seq_lseek,
1904 	.release = single_release,
1905 };
1906 
1907 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1908 			    int read_only)
1909 {
1910 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1911 	int res = 0;
1912 
1913 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1914 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1915 			 "forcing read-only mode");
1916 		res = MS_RDONLY;
1917 	}
1918 	if (read_only)
1919 		goto done;
1920 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1921 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1922 			 "running e2fsck is recommended");
1923 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
1924 		ext4_msg(sb, KERN_WARNING,
1925 			 "warning: mounting fs with errors, "
1926 			 "running e2fsck is recommended");
1927 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1928 		 le16_to_cpu(es->s_mnt_count) >=
1929 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1930 		ext4_msg(sb, KERN_WARNING,
1931 			 "warning: maximal mount count reached, "
1932 			 "running e2fsck is recommended");
1933 	else if (le32_to_cpu(es->s_checkinterval) &&
1934 		(le32_to_cpu(es->s_lastcheck) +
1935 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1936 		ext4_msg(sb, KERN_WARNING,
1937 			 "warning: checktime reached, "
1938 			 "running e2fsck is recommended");
1939 	if (!sbi->s_journal)
1940 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1941 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1942 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1943 	le16_add_cpu(&es->s_mnt_count, 1);
1944 	es->s_mtime = cpu_to_le32(get_seconds());
1945 	ext4_update_dynamic_rev(sb);
1946 	if (sbi->s_journal)
1947 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1948 
1949 	ext4_commit_super(sb, 1);
1950 done:
1951 	if (test_opt(sb, DEBUG))
1952 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1953 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1954 			sb->s_blocksize,
1955 			sbi->s_groups_count,
1956 			EXT4_BLOCKS_PER_GROUP(sb),
1957 			EXT4_INODES_PER_GROUP(sb),
1958 			sbi->s_mount_opt, sbi->s_mount_opt2);
1959 
1960 	cleancache_init_fs(sb);
1961 	return res;
1962 }
1963 
1964 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1965 {
1966 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1967 	struct flex_groups *new_groups;
1968 	int size;
1969 
1970 	if (!sbi->s_log_groups_per_flex)
1971 		return 0;
1972 
1973 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
1974 	if (size <= sbi->s_flex_groups_allocated)
1975 		return 0;
1976 
1977 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1978 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1979 	if (!new_groups) {
1980 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1981 			 size / (int) sizeof(struct flex_groups));
1982 		return -ENOMEM;
1983 	}
1984 
1985 	if (sbi->s_flex_groups) {
1986 		memcpy(new_groups, sbi->s_flex_groups,
1987 		       (sbi->s_flex_groups_allocated *
1988 			sizeof(struct flex_groups)));
1989 		kvfree(sbi->s_flex_groups);
1990 	}
1991 	sbi->s_flex_groups = new_groups;
1992 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1993 	return 0;
1994 }
1995 
1996 static int ext4_fill_flex_info(struct super_block *sb)
1997 {
1998 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1999 	struct ext4_group_desc *gdp = NULL;
2000 	ext4_group_t flex_group;
2001 	int i, err;
2002 
2003 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2004 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2005 		sbi->s_log_groups_per_flex = 0;
2006 		return 1;
2007 	}
2008 
2009 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2010 	if (err)
2011 		goto failed;
2012 
2013 	for (i = 0; i < sbi->s_groups_count; i++) {
2014 		gdp = ext4_get_group_desc(sb, i, NULL);
2015 
2016 		flex_group = ext4_flex_group(sbi, i);
2017 		atomic_add(ext4_free_inodes_count(sb, gdp),
2018 			   &sbi->s_flex_groups[flex_group].free_inodes);
2019 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2020 			     &sbi->s_flex_groups[flex_group].free_clusters);
2021 		atomic_add(ext4_used_dirs_count(sb, gdp),
2022 			   &sbi->s_flex_groups[flex_group].used_dirs);
2023 	}
2024 
2025 	return 1;
2026 failed:
2027 	return 0;
2028 }
2029 
2030 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2031 				   struct ext4_group_desc *gdp)
2032 {
2033 	int offset;
2034 	__u16 crc = 0;
2035 	__le32 le_group = cpu_to_le32(block_group);
2036 
2037 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2038 		/* Use new metadata_csum algorithm */
2039 		__le16 save_csum;
2040 		__u32 csum32;
2041 
2042 		save_csum = gdp->bg_checksum;
2043 		gdp->bg_checksum = 0;
2044 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2045 				     sizeof(le_group));
2046 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2047 				     sbi->s_desc_size);
2048 		gdp->bg_checksum = save_csum;
2049 
2050 		crc = csum32 & 0xFFFF;
2051 		goto out;
2052 	}
2053 
2054 	/* old crc16 code */
2055 	if (!(sbi->s_es->s_feature_ro_compat &
2056 	      cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)))
2057 		return 0;
2058 
2059 	offset = offsetof(struct ext4_group_desc, bg_checksum);
2060 
2061 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2062 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2063 	crc = crc16(crc, (__u8 *)gdp, offset);
2064 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2065 	/* for checksum of struct ext4_group_desc do the rest...*/
2066 	if ((sbi->s_es->s_feature_incompat &
2067 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2068 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2069 		crc = crc16(crc, (__u8 *)gdp + offset,
2070 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2071 				offset);
2072 
2073 out:
2074 	return cpu_to_le16(crc);
2075 }
2076 
2077 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2078 				struct ext4_group_desc *gdp)
2079 {
2080 	if (ext4_has_group_desc_csum(sb) &&
2081 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2082 						      block_group, gdp)))
2083 		return 0;
2084 
2085 	return 1;
2086 }
2087 
2088 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2089 			      struct ext4_group_desc *gdp)
2090 {
2091 	if (!ext4_has_group_desc_csum(sb))
2092 		return;
2093 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2094 }
2095 
2096 /* Called at mount-time, super-block is locked */
2097 static int ext4_check_descriptors(struct super_block *sb,
2098 				  ext4_group_t *first_not_zeroed)
2099 {
2100 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2101 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2102 	ext4_fsblk_t last_block;
2103 	ext4_fsblk_t block_bitmap;
2104 	ext4_fsblk_t inode_bitmap;
2105 	ext4_fsblk_t inode_table;
2106 	int flexbg_flag = 0;
2107 	ext4_group_t i, grp = sbi->s_groups_count;
2108 
2109 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2110 		flexbg_flag = 1;
2111 
2112 	ext4_debug("Checking group descriptors");
2113 
2114 	for (i = 0; i < sbi->s_groups_count; i++) {
2115 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2116 
2117 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2118 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2119 		else
2120 			last_block = first_block +
2121 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2122 
2123 		if ((grp == sbi->s_groups_count) &&
2124 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2125 			grp = i;
2126 
2127 		block_bitmap = ext4_block_bitmap(sb, gdp);
2128 		if (block_bitmap < first_block || block_bitmap > last_block) {
2129 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2130 			       "Block bitmap for group %u not in group "
2131 			       "(block %llu)!", i, block_bitmap);
2132 			return 0;
2133 		}
2134 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2135 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2136 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2137 			       "Inode bitmap for group %u not in group "
2138 			       "(block %llu)!", i, inode_bitmap);
2139 			return 0;
2140 		}
2141 		inode_table = ext4_inode_table(sb, gdp);
2142 		if (inode_table < first_block ||
2143 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2144 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2145 			       "Inode table for group %u not in group "
2146 			       "(block %llu)!", i, inode_table);
2147 			return 0;
2148 		}
2149 		ext4_lock_group(sb, i);
2150 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2151 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2152 				 "Checksum for group %u failed (%u!=%u)",
2153 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2154 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2155 			if (!(sb->s_flags & MS_RDONLY)) {
2156 				ext4_unlock_group(sb, i);
2157 				return 0;
2158 			}
2159 		}
2160 		ext4_unlock_group(sb, i);
2161 		if (!flexbg_flag)
2162 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2163 	}
2164 	if (NULL != first_not_zeroed)
2165 		*first_not_zeroed = grp;
2166 	return 1;
2167 }
2168 
2169 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2170  * the superblock) which were deleted from all directories, but held open by
2171  * a process at the time of a crash.  We walk the list and try to delete these
2172  * inodes at recovery time (only with a read-write filesystem).
2173  *
2174  * In order to keep the orphan inode chain consistent during traversal (in
2175  * case of crash during recovery), we link each inode into the superblock
2176  * orphan list_head and handle it the same way as an inode deletion during
2177  * normal operation (which journals the operations for us).
2178  *
2179  * We only do an iget() and an iput() on each inode, which is very safe if we
2180  * accidentally point at an in-use or already deleted inode.  The worst that
2181  * can happen in this case is that we get a "bit already cleared" message from
2182  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2183  * e2fsck was run on this filesystem, and it must have already done the orphan
2184  * inode cleanup for us, so we can safely abort without any further action.
2185  */
2186 static void ext4_orphan_cleanup(struct super_block *sb,
2187 				struct ext4_super_block *es)
2188 {
2189 	unsigned int s_flags = sb->s_flags;
2190 	int nr_orphans = 0, nr_truncates = 0;
2191 #ifdef CONFIG_QUOTA
2192 	int i;
2193 #endif
2194 	if (!es->s_last_orphan) {
2195 		jbd_debug(4, "no orphan inodes to clean up\n");
2196 		return;
2197 	}
2198 
2199 	if (bdev_read_only(sb->s_bdev)) {
2200 		ext4_msg(sb, KERN_ERR, "write access "
2201 			"unavailable, skipping orphan cleanup");
2202 		return;
2203 	}
2204 
2205 	/* Check if feature set would not allow a r/w mount */
2206 	if (!ext4_feature_set_ok(sb, 0)) {
2207 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2208 			 "unknown ROCOMPAT features");
2209 		return;
2210 	}
2211 
2212 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2213 		/* don't clear list on RO mount w/ errors */
2214 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2215 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2216 				  "clearing orphan list.\n");
2217 			es->s_last_orphan = 0;
2218 		}
2219 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2220 		return;
2221 	}
2222 
2223 	if (s_flags & MS_RDONLY) {
2224 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2225 		sb->s_flags &= ~MS_RDONLY;
2226 	}
2227 #ifdef CONFIG_QUOTA
2228 	/* Needed for iput() to work correctly and not trash data */
2229 	sb->s_flags |= MS_ACTIVE;
2230 	/* Turn on quotas so that they are updated correctly */
2231 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2232 		if (EXT4_SB(sb)->s_qf_names[i]) {
2233 			int ret = ext4_quota_on_mount(sb, i);
2234 			if (ret < 0)
2235 				ext4_msg(sb, KERN_ERR,
2236 					"Cannot turn on journaled "
2237 					"quota: error %d", ret);
2238 		}
2239 	}
2240 #endif
2241 
2242 	while (es->s_last_orphan) {
2243 		struct inode *inode;
2244 
2245 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2246 		if (IS_ERR(inode)) {
2247 			es->s_last_orphan = 0;
2248 			break;
2249 		}
2250 
2251 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2252 		dquot_initialize(inode);
2253 		if (inode->i_nlink) {
2254 			if (test_opt(sb, DEBUG))
2255 				ext4_msg(sb, KERN_DEBUG,
2256 					"%s: truncating inode %lu to %lld bytes",
2257 					__func__, inode->i_ino, inode->i_size);
2258 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2259 				  inode->i_ino, inode->i_size);
2260 			mutex_lock(&inode->i_mutex);
2261 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2262 			ext4_truncate(inode);
2263 			mutex_unlock(&inode->i_mutex);
2264 			nr_truncates++;
2265 		} else {
2266 			if (test_opt(sb, DEBUG))
2267 				ext4_msg(sb, KERN_DEBUG,
2268 					"%s: deleting unreferenced inode %lu",
2269 					__func__, inode->i_ino);
2270 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2271 				  inode->i_ino);
2272 			nr_orphans++;
2273 		}
2274 		iput(inode);  /* The delete magic happens here! */
2275 	}
2276 
2277 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2278 
2279 	if (nr_orphans)
2280 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2281 		       PLURAL(nr_orphans));
2282 	if (nr_truncates)
2283 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2284 		       PLURAL(nr_truncates));
2285 #ifdef CONFIG_QUOTA
2286 	/* Turn quotas off */
2287 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2288 		if (sb_dqopt(sb)->files[i])
2289 			dquot_quota_off(sb, i);
2290 	}
2291 #endif
2292 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2293 }
2294 
2295 /*
2296  * Maximal extent format file size.
2297  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2298  * extent format containers, within a sector_t, and within i_blocks
2299  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2300  * so that won't be a limiting factor.
2301  *
2302  * However there is other limiting factor. We do store extents in the form
2303  * of starting block and length, hence the resulting length of the extent
2304  * covering maximum file size must fit into on-disk format containers as
2305  * well. Given that length is always by 1 unit bigger than max unit (because
2306  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2307  *
2308  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2309  */
2310 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2311 {
2312 	loff_t res;
2313 	loff_t upper_limit = MAX_LFS_FILESIZE;
2314 
2315 	/* small i_blocks in vfs inode? */
2316 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2317 		/*
2318 		 * CONFIG_LBDAF is not enabled implies the inode
2319 		 * i_block represent total blocks in 512 bytes
2320 		 * 32 == size of vfs inode i_blocks * 8
2321 		 */
2322 		upper_limit = (1LL << 32) - 1;
2323 
2324 		/* total blocks in file system block size */
2325 		upper_limit >>= (blkbits - 9);
2326 		upper_limit <<= blkbits;
2327 	}
2328 
2329 	/*
2330 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2331 	 * by one fs block, so ee_len can cover the extent of maximum file
2332 	 * size
2333 	 */
2334 	res = (1LL << 32) - 1;
2335 	res <<= blkbits;
2336 
2337 	/* Sanity check against vm- & vfs- imposed limits */
2338 	if (res > upper_limit)
2339 		res = upper_limit;
2340 
2341 	return res;
2342 }
2343 
2344 /*
2345  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2346  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2347  * We need to be 1 filesystem block less than the 2^48 sector limit.
2348  */
2349 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2350 {
2351 	loff_t res = EXT4_NDIR_BLOCKS;
2352 	int meta_blocks;
2353 	loff_t upper_limit;
2354 	/* This is calculated to be the largest file size for a dense, block
2355 	 * mapped file such that the file's total number of 512-byte sectors,
2356 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2357 	 *
2358 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2359 	 * number of 512-byte sectors of the file.
2360 	 */
2361 
2362 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2363 		/*
2364 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2365 		 * the inode i_block field represents total file blocks in
2366 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2367 		 */
2368 		upper_limit = (1LL << 32) - 1;
2369 
2370 		/* total blocks in file system block size */
2371 		upper_limit >>= (bits - 9);
2372 
2373 	} else {
2374 		/*
2375 		 * We use 48 bit ext4_inode i_blocks
2376 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2377 		 * represent total number of blocks in
2378 		 * file system block size
2379 		 */
2380 		upper_limit = (1LL << 48) - 1;
2381 
2382 	}
2383 
2384 	/* indirect blocks */
2385 	meta_blocks = 1;
2386 	/* double indirect blocks */
2387 	meta_blocks += 1 + (1LL << (bits-2));
2388 	/* tripple indirect blocks */
2389 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2390 
2391 	upper_limit -= meta_blocks;
2392 	upper_limit <<= bits;
2393 
2394 	res += 1LL << (bits-2);
2395 	res += 1LL << (2*(bits-2));
2396 	res += 1LL << (3*(bits-2));
2397 	res <<= bits;
2398 	if (res > upper_limit)
2399 		res = upper_limit;
2400 
2401 	if (res > MAX_LFS_FILESIZE)
2402 		res = MAX_LFS_FILESIZE;
2403 
2404 	return res;
2405 }
2406 
2407 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2408 				   ext4_fsblk_t logical_sb_block, int nr)
2409 {
2410 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2411 	ext4_group_t bg, first_meta_bg;
2412 	int has_super = 0;
2413 
2414 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2415 
2416 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2417 	    nr < first_meta_bg)
2418 		return logical_sb_block + nr + 1;
2419 	bg = sbi->s_desc_per_block * nr;
2420 	if (ext4_bg_has_super(sb, bg))
2421 		has_super = 1;
2422 
2423 	/*
2424 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2425 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2426 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2427 	 * compensate.
2428 	 */
2429 	if (sb->s_blocksize == 1024 && nr == 0 &&
2430 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2431 		has_super++;
2432 
2433 	return (has_super + ext4_group_first_block_no(sb, bg));
2434 }
2435 
2436 /**
2437  * ext4_get_stripe_size: Get the stripe size.
2438  * @sbi: In memory super block info
2439  *
2440  * If we have specified it via mount option, then
2441  * use the mount option value. If the value specified at mount time is
2442  * greater than the blocks per group use the super block value.
2443  * If the super block value is greater than blocks per group return 0.
2444  * Allocator needs it be less than blocks per group.
2445  *
2446  */
2447 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2448 {
2449 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2450 	unsigned long stripe_width =
2451 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2452 	int ret;
2453 
2454 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2455 		ret = sbi->s_stripe;
2456 	else if (stripe_width <= sbi->s_blocks_per_group)
2457 		ret = stripe_width;
2458 	else if (stride <= sbi->s_blocks_per_group)
2459 		ret = stride;
2460 	else
2461 		ret = 0;
2462 
2463 	/*
2464 	 * If the stripe width is 1, this makes no sense and
2465 	 * we set it to 0 to turn off stripe handling code.
2466 	 */
2467 	if (ret <= 1)
2468 		ret = 0;
2469 
2470 	return ret;
2471 }
2472 
2473 /* sysfs supprt */
2474 
2475 struct ext4_attr {
2476 	struct attribute attr;
2477 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2478 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2479 			 const char *, size_t);
2480 	union {
2481 		int offset;
2482 		int deprecated_val;
2483 	} u;
2484 };
2485 
2486 static int parse_strtoull(const char *buf,
2487 		unsigned long long max, unsigned long long *value)
2488 {
2489 	int ret;
2490 
2491 	ret = kstrtoull(skip_spaces(buf), 0, value);
2492 	if (!ret && *value > max)
2493 		ret = -EINVAL;
2494 	return ret;
2495 }
2496 
2497 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2498 					      struct ext4_sb_info *sbi,
2499 					      char *buf)
2500 {
2501 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2502 		(s64) EXT4_C2B(sbi,
2503 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2504 }
2505 
2506 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2507 					 struct ext4_sb_info *sbi, char *buf)
2508 {
2509 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2510 
2511 	if (!sb->s_bdev->bd_part)
2512 		return snprintf(buf, PAGE_SIZE, "0\n");
2513 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2514 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2515 			 sbi->s_sectors_written_start) >> 1);
2516 }
2517 
2518 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2519 					  struct ext4_sb_info *sbi, char *buf)
2520 {
2521 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2522 
2523 	if (!sb->s_bdev->bd_part)
2524 		return snprintf(buf, PAGE_SIZE, "0\n");
2525 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2526 			(unsigned long long)(sbi->s_kbytes_written +
2527 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2528 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2529 }
2530 
2531 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2532 					  struct ext4_sb_info *sbi,
2533 					  const char *buf, size_t count)
2534 {
2535 	unsigned long t;
2536 	int ret;
2537 
2538 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2539 	if (ret)
2540 		return ret;
2541 
2542 	if (t && (!is_power_of_2(t) || t > 0x40000000))
2543 		return -EINVAL;
2544 
2545 	sbi->s_inode_readahead_blks = t;
2546 	return count;
2547 }
2548 
2549 static ssize_t sbi_ui_show(struct ext4_attr *a,
2550 			   struct ext4_sb_info *sbi, char *buf)
2551 {
2552 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2553 
2554 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2555 }
2556 
2557 static ssize_t sbi_ui_store(struct ext4_attr *a,
2558 			    struct ext4_sb_info *sbi,
2559 			    const char *buf, size_t count)
2560 {
2561 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2562 	unsigned long t;
2563 	int ret;
2564 
2565 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2566 	if (ret)
2567 		return ret;
2568 	*ui = t;
2569 	return count;
2570 }
2571 
2572 static ssize_t es_ui_show(struct ext4_attr *a,
2573 			   struct ext4_sb_info *sbi, char *buf)
2574 {
2575 
2576 	unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
2577 			   a->u.offset);
2578 
2579 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2580 }
2581 
2582 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2583 				  struct ext4_sb_info *sbi, char *buf)
2584 {
2585 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2586 		(unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2587 }
2588 
2589 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2590 				   struct ext4_sb_info *sbi,
2591 				   const char *buf, size_t count)
2592 {
2593 	unsigned long long val;
2594 	int ret;
2595 
2596 	if (parse_strtoull(buf, -1ULL, &val))
2597 		return -EINVAL;
2598 	ret = ext4_reserve_clusters(sbi, val);
2599 
2600 	return ret ? ret : count;
2601 }
2602 
2603 static ssize_t trigger_test_error(struct ext4_attr *a,
2604 				  struct ext4_sb_info *sbi,
2605 				  const char *buf, size_t count)
2606 {
2607 	int len = count;
2608 
2609 	if (!capable(CAP_SYS_ADMIN))
2610 		return -EPERM;
2611 
2612 	if (len && buf[len-1] == '\n')
2613 		len--;
2614 
2615 	if (len)
2616 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2617 	return count;
2618 }
2619 
2620 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2621 				   struct ext4_sb_info *sbi, char *buf)
2622 {
2623 	return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2624 }
2625 
2626 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2627 static struct ext4_attr ext4_attr_##_name = {			\
2628 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2629 	.show	= _show,					\
2630 	.store	= _store,					\
2631 	.u = {							\
2632 		.offset = offsetof(struct ext4_sb_info, _elname),\
2633 	},							\
2634 }
2635 
2636 #define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)		\
2637 static struct ext4_attr ext4_attr_##_name = {				\
2638 	.attr = {.name = __stringify(_name), .mode = _mode },		\
2639 	.show	= _show,						\
2640 	.store	= _store,						\
2641 	.u = {								\
2642 		.offset = offsetof(struct ext4_super_block, _elname),	\
2643 	},								\
2644 }
2645 
2646 #define EXT4_ATTR(name, mode, show, store) \
2647 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2648 
2649 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2650 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2651 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2652 
2653 #define EXT4_RO_ATTR_ES_UI(name, elname)	\
2654 	EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
2655 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2656 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2657 
2658 #define ATTR_LIST(name) &ext4_attr_##name.attr
2659 #define EXT4_DEPRECATED_ATTR(_name, _val)	\
2660 static struct ext4_attr ext4_attr_##_name = {			\
2661 	.attr = {.name = __stringify(_name), .mode = 0444 },	\
2662 	.show	= sbi_deprecated_show,				\
2663 	.u = {							\
2664 		.deprecated_val = _val,				\
2665 	},							\
2666 }
2667 
2668 EXT4_RO_ATTR(delayed_allocation_blocks);
2669 EXT4_RO_ATTR(session_write_kbytes);
2670 EXT4_RO_ATTR(lifetime_write_kbytes);
2671 EXT4_RW_ATTR(reserved_clusters);
2672 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2673 		 inode_readahead_blks_store, s_inode_readahead_blks);
2674 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2675 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2676 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2677 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2678 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2679 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2680 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2681 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2682 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2683 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2684 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2685 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2686 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2687 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2688 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2689 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2690 EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
2691 EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
2692 EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
2693 
2694 static struct attribute *ext4_attrs[] = {
2695 	ATTR_LIST(delayed_allocation_blocks),
2696 	ATTR_LIST(session_write_kbytes),
2697 	ATTR_LIST(lifetime_write_kbytes),
2698 	ATTR_LIST(reserved_clusters),
2699 	ATTR_LIST(inode_readahead_blks),
2700 	ATTR_LIST(inode_goal),
2701 	ATTR_LIST(mb_stats),
2702 	ATTR_LIST(mb_max_to_scan),
2703 	ATTR_LIST(mb_min_to_scan),
2704 	ATTR_LIST(mb_order2_req),
2705 	ATTR_LIST(mb_stream_req),
2706 	ATTR_LIST(mb_group_prealloc),
2707 	ATTR_LIST(max_writeback_mb_bump),
2708 	ATTR_LIST(extent_max_zeroout_kb),
2709 	ATTR_LIST(trigger_fs_error),
2710 	ATTR_LIST(err_ratelimit_interval_ms),
2711 	ATTR_LIST(err_ratelimit_burst),
2712 	ATTR_LIST(warning_ratelimit_interval_ms),
2713 	ATTR_LIST(warning_ratelimit_burst),
2714 	ATTR_LIST(msg_ratelimit_interval_ms),
2715 	ATTR_LIST(msg_ratelimit_burst),
2716 	ATTR_LIST(errors_count),
2717 	ATTR_LIST(first_error_time),
2718 	ATTR_LIST(last_error_time),
2719 	NULL,
2720 };
2721 
2722 /* Features this copy of ext4 supports */
2723 EXT4_INFO_ATTR(lazy_itable_init);
2724 EXT4_INFO_ATTR(batched_discard);
2725 EXT4_INFO_ATTR(meta_bg_resize);
2726 EXT4_INFO_ATTR(encryption);
2727 
2728 static struct attribute *ext4_feat_attrs[] = {
2729 	ATTR_LIST(lazy_itable_init),
2730 	ATTR_LIST(batched_discard),
2731 	ATTR_LIST(meta_bg_resize),
2732 	ATTR_LIST(encryption),
2733 	NULL,
2734 };
2735 
2736 static ssize_t ext4_attr_show(struct kobject *kobj,
2737 			      struct attribute *attr, char *buf)
2738 {
2739 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2740 						s_kobj);
2741 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2742 
2743 	return a->show ? a->show(a, sbi, buf) : 0;
2744 }
2745 
2746 static ssize_t ext4_attr_store(struct kobject *kobj,
2747 			       struct attribute *attr,
2748 			       const char *buf, size_t len)
2749 {
2750 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2751 						s_kobj);
2752 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2753 
2754 	return a->store ? a->store(a, sbi, buf, len) : 0;
2755 }
2756 
2757 static void ext4_sb_release(struct kobject *kobj)
2758 {
2759 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2760 						s_kobj);
2761 	complete(&sbi->s_kobj_unregister);
2762 }
2763 
2764 static const struct sysfs_ops ext4_attr_ops = {
2765 	.show	= ext4_attr_show,
2766 	.store	= ext4_attr_store,
2767 };
2768 
2769 static struct kobj_type ext4_ktype = {
2770 	.default_attrs	= ext4_attrs,
2771 	.sysfs_ops	= &ext4_attr_ops,
2772 	.release	= ext4_sb_release,
2773 };
2774 
2775 static void ext4_feat_release(struct kobject *kobj)
2776 {
2777 	complete(&ext4_feat->f_kobj_unregister);
2778 }
2779 
2780 static ssize_t ext4_feat_show(struct kobject *kobj,
2781 			      struct attribute *attr, char *buf)
2782 {
2783 	return snprintf(buf, PAGE_SIZE, "supported\n");
2784 }
2785 
2786 /*
2787  * We can not use ext4_attr_show/store because it relies on the kobject
2788  * being embedded in the ext4_sb_info structure which is definitely not
2789  * true in this case.
2790  */
2791 static const struct sysfs_ops ext4_feat_ops = {
2792 	.show	= ext4_feat_show,
2793 	.store	= NULL,
2794 };
2795 
2796 static struct kobj_type ext4_feat_ktype = {
2797 	.default_attrs	= ext4_feat_attrs,
2798 	.sysfs_ops	= &ext4_feat_ops,
2799 	.release	= ext4_feat_release,
2800 };
2801 
2802 /*
2803  * Check whether this filesystem can be mounted based on
2804  * the features present and the RDONLY/RDWR mount requested.
2805  * Returns 1 if this filesystem can be mounted as requested,
2806  * 0 if it cannot be.
2807  */
2808 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2809 {
2810 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2811 		ext4_msg(sb, KERN_ERR,
2812 			"Couldn't mount because of "
2813 			"unsupported optional features (%x)",
2814 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2815 			~EXT4_FEATURE_INCOMPAT_SUPP));
2816 		return 0;
2817 	}
2818 
2819 	if (readonly)
2820 		return 1;
2821 
2822 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_READONLY)) {
2823 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2824 		sb->s_flags |= MS_RDONLY;
2825 		return 1;
2826 	}
2827 
2828 	/* Check that feature set is OK for a read-write mount */
2829 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2830 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2831 			 "unsupported optional features (%x)",
2832 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2833 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2834 		return 0;
2835 	}
2836 	/*
2837 	 * Large file size enabled file system can only be mounted
2838 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2839 	 */
2840 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2841 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2842 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2843 				 "cannot be mounted RDWR without "
2844 				 "CONFIG_LBDAF");
2845 			return 0;
2846 		}
2847 	}
2848 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2849 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2850 		ext4_msg(sb, KERN_ERR,
2851 			 "Can't support bigalloc feature without "
2852 			 "extents feature\n");
2853 		return 0;
2854 	}
2855 
2856 #ifndef CONFIG_QUOTA
2857 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2858 	    !readonly) {
2859 		ext4_msg(sb, KERN_ERR,
2860 			 "Filesystem with quota feature cannot be mounted RDWR "
2861 			 "without CONFIG_QUOTA");
2862 		return 0;
2863 	}
2864 #endif  /* CONFIG_QUOTA */
2865 	return 1;
2866 }
2867 
2868 /*
2869  * This function is called once a day if we have errors logged
2870  * on the file system
2871  */
2872 static void print_daily_error_info(unsigned long arg)
2873 {
2874 	struct super_block *sb = (struct super_block *) arg;
2875 	struct ext4_sb_info *sbi;
2876 	struct ext4_super_block *es;
2877 
2878 	sbi = EXT4_SB(sb);
2879 	es = sbi->s_es;
2880 
2881 	if (es->s_error_count)
2882 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2883 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2884 			 le32_to_cpu(es->s_error_count));
2885 	if (es->s_first_error_time) {
2886 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2887 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2888 		       (int) sizeof(es->s_first_error_func),
2889 		       es->s_first_error_func,
2890 		       le32_to_cpu(es->s_first_error_line));
2891 		if (es->s_first_error_ino)
2892 			printk(": inode %u",
2893 			       le32_to_cpu(es->s_first_error_ino));
2894 		if (es->s_first_error_block)
2895 			printk(": block %llu", (unsigned long long)
2896 			       le64_to_cpu(es->s_first_error_block));
2897 		printk("\n");
2898 	}
2899 	if (es->s_last_error_time) {
2900 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2901 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2902 		       (int) sizeof(es->s_last_error_func),
2903 		       es->s_last_error_func,
2904 		       le32_to_cpu(es->s_last_error_line));
2905 		if (es->s_last_error_ino)
2906 			printk(": inode %u",
2907 			       le32_to_cpu(es->s_last_error_ino));
2908 		if (es->s_last_error_block)
2909 			printk(": block %llu", (unsigned long long)
2910 			       le64_to_cpu(es->s_last_error_block));
2911 		printk("\n");
2912 	}
2913 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2914 }
2915 
2916 /* Find next suitable group and run ext4_init_inode_table */
2917 static int ext4_run_li_request(struct ext4_li_request *elr)
2918 {
2919 	struct ext4_group_desc *gdp = NULL;
2920 	ext4_group_t group, ngroups;
2921 	struct super_block *sb;
2922 	unsigned long timeout = 0;
2923 	int ret = 0;
2924 
2925 	sb = elr->lr_super;
2926 	ngroups = EXT4_SB(sb)->s_groups_count;
2927 
2928 	sb_start_write(sb);
2929 	for (group = elr->lr_next_group; group < ngroups; group++) {
2930 		gdp = ext4_get_group_desc(sb, group, NULL);
2931 		if (!gdp) {
2932 			ret = 1;
2933 			break;
2934 		}
2935 
2936 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2937 			break;
2938 	}
2939 
2940 	if (group >= ngroups)
2941 		ret = 1;
2942 
2943 	if (!ret) {
2944 		timeout = jiffies;
2945 		ret = ext4_init_inode_table(sb, group,
2946 					    elr->lr_timeout ? 0 : 1);
2947 		if (elr->lr_timeout == 0) {
2948 			timeout = (jiffies - timeout) *
2949 				  elr->lr_sbi->s_li_wait_mult;
2950 			elr->lr_timeout = timeout;
2951 		}
2952 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2953 		elr->lr_next_group = group + 1;
2954 	}
2955 	sb_end_write(sb);
2956 
2957 	return ret;
2958 }
2959 
2960 /*
2961  * Remove lr_request from the list_request and free the
2962  * request structure. Should be called with li_list_mtx held
2963  */
2964 static void ext4_remove_li_request(struct ext4_li_request *elr)
2965 {
2966 	struct ext4_sb_info *sbi;
2967 
2968 	if (!elr)
2969 		return;
2970 
2971 	sbi = elr->lr_sbi;
2972 
2973 	list_del(&elr->lr_request);
2974 	sbi->s_li_request = NULL;
2975 	kfree(elr);
2976 }
2977 
2978 static void ext4_unregister_li_request(struct super_block *sb)
2979 {
2980 	mutex_lock(&ext4_li_mtx);
2981 	if (!ext4_li_info) {
2982 		mutex_unlock(&ext4_li_mtx);
2983 		return;
2984 	}
2985 
2986 	mutex_lock(&ext4_li_info->li_list_mtx);
2987 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2988 	mutex_unlock(&ext4_li_info->li_list_mtx);
2989 	mutex_unlock(&ext4_li_mtx);
2990 }
2991 
2992 static struct task_struct *ext4_lazyinit_task;
2993 
2994 /*
2995  * This is the function where ext4lazyinit thread lives. It walks
2996  * through the request list searching for next scheduled filesystem.
2997  * When such a fs is found, run the lazy initialization request
2998  * (ext4_rn_li_request) and keep track of the time spend in this
2999  * function. Based on that time we compute next schedule time of
3000  * the request. When walking through the list is complete, compute
3001  * next waking time and put itself into sleep.
3002  */
3003 static int ext4_lazyinit_thread(void *arg)
3004 {
3005 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3006 	struct list_head *pos, *n;
3007 	struct ext4_li_request *elr;
3008 	unsigned long next_wakeup, cur;
3009 
3010 	BUG_ON(NULL == eli);
3011 
3012 cont_thread:
3013 	while (true) {
3014 		next_wakeup = MAX_JIFFY_OFFSET;
3015 
3016 		mutex_lock(&eli->li_list_mtx);
3017 		if (list_empty(&eli->li_request_list)) {
3018 			mutex_unlock(&eli->li_list_mtx);
3019 			goto exit_thread;
3020 		}
3021 
3022 		list_for_each_safe(pos, n, &eli->li_request_list) {
3023 			elr = list_entry(pos, struct ext4_li_request,
3024 					 lr_request);
3025 
3026 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
3027 				if (ext4_run_li_request(elr) != 0) {
3028 					/* error, remove the lazy_init job */
3029 					ext4_remove_li_request(elr);
3030 					continue;
3031 				}
3032 			}
3033 
3034 			if (time_before(elr->lr_next_sched, next_wakeup))
3035 				next_wakeup = elr->lr_next_sched;
3036 		}
3037 		mutex_unlock(&eli->li_list_mtx);
3038 
3039 		try_to_freeze();
3040 
3041 		cur = jiffies;
3042 		if ((time_after_eq(cur, next_wakeup)) ||
3043 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3044 			cond_resched();
3045 			continue;
3046 		}
3047 
3048 		schedule_timeout_interruptible(next_wakeup - cur);
3049 
3050 		if (kthread_should_stop()) {
3051 			ext4_clear_request_list();
3052 			goto exit_thread;
3053 		}
3054 	}
3055 
3056 exit_thread:
3057 	/*
3058 	 * It looks like the request list is empty, but we need
3059 	 * to check it under the li_list_mtx lock, to prevent any
3060 	 * additions into it, and of course we should lock ext4_li_mtx
3061 	 * to atomically free the list and ext4_li_info, because at
3062 	 * this point another ext4 filesystem could be registering
3063 	 * new one.
3064 	 */
3065 	mutex_lock(&ext4_li_mtx);
3066 	mutex_lock(&eli->li_list_mtx);
3067 	if (!list_empty(&eli->li_request_list)) {
3068 		mutex_unlock(&eli->li_list_mtx);
3069 		mutex_unlock(&ext4_li_mtx);
3070 		goto cont_thread;
3071 	}
3072 	mutex_unlock(&eli->li_list_mtx);
3073 	kfree(ext4_li_info);
3074 	ext4_li_info = NULL;
3075 	mutex_unlock(&ext4_li_mtx);
3076 
3077 	return 0;
3078 }
3079 
3080 static void ext4_clear_request_list(void)
3081 {
3082 	struct list_head *pos, *n;
3083 	struct ext4_li_request *elr;
3084 
3085 	mutex_lock(&ext4_li_info->li_list_mtx);
3086 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3087 		elr = list_entry(pos, struct ext4_li_request,
3088 				 lr_request);
3089 		ext4_remove_li_request(elr);
3090 	}
3091 	mutex_unlock(&ext4_li_info->li_list_mtx);
3092 }
3093 
3094 static int ext4_run_lazyinit_thread(void)
3095 {
3096 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3097 					 ext4_li_info, "ext4lazyinit");
3098 	if (IS_ERR(ext4_lazyinit_task)) {
3099 		int err = PTR_ERR(ext4_lazyinit_task);
3100 		ext4_clear_request_list();
3101 		kfree(ext4_li_info);
3102 		ext4_li_info = NULL;
3103 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3104 				 "initialization thread\n",
3105 				 err);
3106 		return err;
3107 	}
3108 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3109 	return 0;
3110 }
3111 
3112 /*
3113  * Check whether it make sense to run itable init. thread or not.
3114  * If there is at least one uninitialized inode table, return
3115  * corresponding group number, else the loop goes through all
3116  * groups and return total number of groups.
3117  */
3118 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3119 {
3120 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3121 	struct ext4_group_desc *gdp = NULL;
3122 
3123 	for (group = 0; group < ngroups; group++) {
3124 		gdp = ext4_get_group_desc(sb, group, NULL);
3125 		if (!gdp)
3126 			continue;
3127 
3128 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3129 			break;
3130 	}
3131 
3132 	return group;
3133 }
3134 
3135 static int ext4_li_info_new(void)
3136 {
3137 	struct ext4_lazy_init *eli = NULL;
3138 
3139 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3140 	if (!eli)
3141 		return -ENOMEM;
3142 
3143 	INIT_LIST_HEAD(&eli->li_request_list);
3144 	mutex_init(&eli->li_list_mtx);
3145 
3146 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3147 
3148 	ext4_li_info = eli;
3149 
3150 	return 0;
3151 }
3152 
3153 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3154 					    ext4_group_t start)
3155 {
3156 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3157 	struct ext4_li_request *elr;
3158 
3159 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3160 	if (!elr)
3161 		return NULL;
3162 
3163 	elr->lr_super = sb;
3164 	elr->lr_sbi = sbi;
3165 	elr->lr_next_group = start;
3166 
3167 	/*
3168 	 * Randomize first schedule time of the request to
3169 	 * spread the inode table initialization requests
3170 	 * better.
3171 	 */
3172 	elr->lr_next_sched = jiffies + (prandom_u32() %
3173 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3174 	return elr;
3175 }
3176 
3177 int ext4_register_li_request(struct super_block *sb,
3178 			     ext4_group_t first_not_zeroed)
3179 {
3180 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3181 	struct ext4_li_request *elr = NULL;
3182 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3183 	int ret = 0;
3184 
3185 	mutex_lock(&ext4_li_mtx);
3186 	if (sbi->s_li_request != NULL) {
3187 		/*
3188 		 * Reset timeout so it can be computed again, because
3189 		 * s_li_wait_mult might have changed.
3190 		 */
3191 		sbi->s_li_request->lr_timeout = 0;
3192 		goto out;
3193 	}
3194 
3195 	if (first_not_zeroed == ngroups ||
3196 	    (sb->s_flags & MS_RDONLY) ||
3197 	    !test_opt(sb, INIT_INODE_TABLE))
3198 		goto out;
3199 
3200 	elr = ext4_li_request_new(sb, first_not_zeroed);
3201 	if (!elr) {
3202 		ret = -ENOMEM;
3203 		goto out;
3204 	}
3205 
3206 	if (NULL == ext4_li_info) {
3207 		ret = ext4_li_info_new();
3208 		if (ret)
3209 			goto out;
3210 	}
3211 
3212 	mutex_lock(&ext4_li_info->li_list_mtx);
3213 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3214 	mutex_unlock(&ext4_li_info->li_list_mtx);
3215 
3216 	sbi->s_li_request = elr;
3217 	/*
3218 	 * set elr to NULL here since it has been inserted to
3219 	 * the request_list and the removal and free of it is
3220 	 * handled by ext4_clear_request_list from now on.
3221 	 */
3222 	elr = NULL;
3223 
3224 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3225 		ret = ext4_run_lazyinit_thread();
3226 		if (ret)
3227 			goto out;
3228 	}
3229 out:
3230 	mutex_unlock(&ext4_li_mtx);
3231 	if (ret)
3232 		kfree(elr);
3233 	return ret;
3234 }
3235 
3236 /*
3237  * We do not need to lock anything since this is called on
3238  * module unload.
3239  */
3240 static void ext4_destroy_lazyinit_thread(void)
3241 {
3242 	/*
3243 	 * If thread exited earlier
3244 	 * there's nothing to be done.
3245 	 */
3246 	if (!ext4_li_info || !ext4_lazyinit_task)
3247 		return;
3248 
3249 	kthread_stop(ext4_lazyinit_task);
3250 }
3251 
3252 static int set_journal_csum_feature_set(struct super_block *sb)
3253 {
3254 	int ret = 1;
3255 	int compat, incompat;
3256 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3257 
3258 	if (ext4_has_metadata_csum(sb)) {
3259 		/* journal checksum v3 */
3260 		compat = 0;
3261 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3262 	} else {
3263 		/* journal checksum v1 */
3264 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3265 		incompat = 0;
3266 	}
3267 
3268 	jbd2_journal_clear_features(sbi->s_journal,
3269 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3270 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3271 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3272 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3273 		ret = jbd2_journal_set_features(sbi->s_journal,
3274 				compat, 0,
3275 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3276 				incompat);
3277 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3278 		ret = jbd2_journal_set_features(sbi->s_journal,
3279 				compat, 0,
3280 				incompat);
3281 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3282 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3283 	} else {
3284 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3285 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3286 	}
3287 
3288 	return ret;
3289 }
3290 
3291 /*
3292  * Note: calculating the overhead so we can be compatible with
3293  * historical BSD practice is quite difficult in the face of
3294  * clusters/bigalloc.  This is because multiple metadata blocks from
3295  * different block group can end up in the same allocation cluster.
3296  * Calculating the exact overhead in the face of clustered allocation
3297  * requires either O(all block bitmaps) in memory or O(number of block
3298  * groups**2) in time.  We will still calculate the superblock for
3299  * older file systems --- and if we come across with a bigalloc file
3300  * system with zero in s_overhead_clusters the estimate will be close to
3301  * correct especially for very large cluster sizes --- but for newer
3302  * file systems, it's better to calculate this figure once at mkfs
3303  * time, and store it in the superblock.  If the superblock value is
3304  * present (even for non-bigalloc file systems), we will use it.
3305  */
3306 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3307 			  char *buf)
3308 {
3309 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3310 	struct ext4_group_desc	*gdp;
3311 	ext4_fsblk_t		first_block, last_block, b;
3312 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3313 	int			s, j, count = 0;
3314 
3315 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3316 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3317 			sbi->s_itb_per_group + 2);
3318 
3319 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3320 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3321 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3322 	for (i = 0; i < ngroups; i++) {
3323 		gdp = ext4_get_group_desc(sb, i, NULL);
3324 		b = ext4_block_bitmap(sb, gdp);
3325 		if (b >= first_block && b <= last_block) {
3326 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3327 			count++;
3328 		}
3329 		b = ext4_inode_bitmap(sb, gdp);
3330 		if (b >= first_block && b <= last_block) {
3331 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3332 			count++;
3333 		}
3334 		b = ext4_inode_table(sb, gdp);
3335 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3336 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3337 				int c = EXT4_B2C(sbi, b - first_block);
3338 				ext4_set_bit(c, buf);
3339 				count++;
3340 			}
3341 		if (i != grp)
3342 			continue;
3343 		s = 0;
3344 		if (ext4_bg_has_super(sb, grp)) {
3345 			ext4_set_bit(s++, buf);
3346 			count++;
3347 		}
3348 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3349 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3350 			count++;
3351 		}
3352 	}
3353 	if (!count)
3354 		return 0;
3355 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3356 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3357 }
3358 
3359 /*
3360  * Compute the overhead and stash it in sbi->s_overhead
3361  */
3362 int ext4_calculate_overhead(struct super_block *sb)
3363 {
3364 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3365 	struct ext4_super_block *es = sbi->s_es;
3366 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3367 	ext4_fsblk_t overhead = 0;
3368 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3369 
3370 	if (!buf)
3371 		return -ENOMEM;
3372 
3373 	/*
3374 	 * Compute the overhead (FS structures).  This is constant
3375 	 * for a given filesystem unless the number of block groups
3376 	 * changes so we cache the previous value until it does.
3377 	 */
3378 
3379 	/*
3380 	 * All of the blocks before first_data_block are overhead
3381 	 */
3382 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3383 
3384 	/*
3385 	 * Add the overhead found in each block group
3386 	 */
3387 	for (i = 0; i < ngroups; i++) {
3388 		int blks;
3389 
3390 		blks = count_overhead(sb, i, buf);
3391 		overhead += blks;
3392 		if (blks)
3393 			memset(buf, 0, PAGE_SIZE);
3394 		cond_resched();
3395 	}
3396 	/* Add the internal journal blocks as well */
3397 	if (sbi->s_journal && !sbi->journal_bdev)
3398 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3399 
3400 	sbi->s_overhead = overhead;
3401 	smp_wmb();
3402 	free_page((unsigned long) buf);
3403 	return 0;
3404 }
3405 
3406 
3407 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3408 {
3409 	ext4_fsblk_t resv_clusters;
3410 
3411 	/*
3412 	 * There's no need to reserve anything when we aren't using extents.
3413 	 * The space estimates are exact, there are no unwritten extents,
3414 	 * hole punching doesn't need new metadata... This is needed especially
3415 	 * to keep ext2/3 backward compatibility.
3416 	 */
3417 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3418 		return 0;
3419 	/*
3420 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3421 	 * This should cover the situations where we can not afford to run
3422 	 * out of space like for example punch hole, or converting
3423 	 * unwritten extents in delalloc path. In most cases such
3424 	 * allocation would require 1, or 2 blocks, higher numbers are
3425 	 * very rare.
3426 	 */
3427 	resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3428 			EXT4_SB(sb)->s_cluster_bits;
3429 
3430 	do_div(resv_clusters, 50);
3431 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3432 
3433 	return resv_clusters;
3434 }
3435 
3436 
3437 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3438 {
3439 	ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3440 				sbi->s_cluster_bits;
3441 
3442 	if (count >= clusters)
3443 		return -EINVAL;
3444 
3445 	atomic64_set(&sbi->s_resv_clusters, count);
3446 	return 0;
3447 }
3448 
3449 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3450 {
3451 	char *orig_data = kstrdup(data, GFP_KERNEL);
3452 	struct buffer_head *bh;
3453 	struct ext4_super_block *es = NULL;
3454 	struct ext4_sb_info *sbi;
3455 	ext4_fsblk_t block;
3456 	ext4_fsblk_t sb_block = get_sb_block(&data);
3457 	ext4_fsblk_t logical_sb_block;
3458 	unsigned long offset = 0;
3459 	unsigned long journal_devnum = 0;
3460 	unsigned long def_mount_opts;
3461 	struct inode *root;
3462 	const char *descr;
3463 	int ret = -ENOMEM;
3464 	int blocksize, clustersize;
3465 	unsigned int db_count;
3466 	unsigned int i;
3467 	int needs_recovery, has_huge_files, has_bigalloc;
3468 	__u64 blocks_count;
3469 	int err = 0;
3470 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3471 	ext4_group_t first_not_zeroed;
3472 
3473 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3474 	if (!sbi)
3475 		goto out_free_orig;
3476 
3477 	sbi->s_blockgroup_lock =
3478 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3479 	if (!sbi->s_blockgroup_lock) {
3480 		kfree(sbi);
3481 		goto out_free_orig;
3482 	}
3483 	sb->s_fs_info = sbi;
3484 	sbi->s_sb = sb;
3485 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3486 	sbi->s_sb_block = sb_block;
3487 	if (sb->s_bdev->bd_part)
3488 		sbi->s_sectors_written_start =
3489 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3490 
3491 	/* Cleanup superblock name */
3492 	strreplace(sb->s_id, '/', '!');
3493 
3494 	/* -EINVAL is default */
3495 	ret = -EINVAL;
3496 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3497 	if (!blocksize) {
3498 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3499 		goto out_fail;
3500 	}
3501 
3502 	/*
3503 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3504 	 * block sizes.  We need to calculate the offset from buffer start.
3505 	 */
3506 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3507 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3508 		offset = do_div(logical_sb_block, blocksize);
3509 	} else {
3510 		logical_sb_block = sb_block;
3511 	}
3512 
3513 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3514 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3515 		goto out_fail;
3516 	}
3517 	/*
3518 	 * Note: s_es must be initialized as soon as possible because
3519 	 *       some ext4 macro-instructions depend on its value
3520 	 */
3521 	es = (struct ext4_super_block *) (bh->b_data + offset);
3522 	sbi->s_es = es;
3523 	sb->s_magic = le16_to_cpu(es->s_magic);
3524 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3525 		goto cantfind_ext4;
3526 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3527 
3528 	/* Warn if metadata_csum and gdt_csum are both set. */
3529 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3530 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3531 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3532 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3533 			     "redundant flags; please run fsck.");
3534 
3535 	/* Check for a known checksum algorithm */
3536 	if (!ext4_verify_csum_type(sb, es)) {
3537 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3538 			 "unknown checksum algorithm.");
3539 		silent = 1;
3540 		goto cantfind_ext4;
3541 	}
3542 
3543 	/* Load the checksum driver */
3544 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3545 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3546 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3547 		if (IS_ERR(sbi->s_chksum_driver)) {
3548 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3549 			ret = PTR_ERR(sbi->s_chksum_driver);
3550 			sbi->s_chksum_driver = NULL;
3551 			goto failed_mount;
3552 		}
3553 	}
3554 
3555 	/* Check superblock checksum */
3556 	if (!ext4_superblock_csum_verify(sb, es)) {
3557 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3558 			 "invalid superblock checksum.  Run e2fsck?");
3559 		silent = 1;
3560 		goto cantfind_ext4;
3561 	}
3562 
3563 	/* Precompute checksum seed for all metadata */
3564 	if (ext4_has_metadata_csum(sb))
3565 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3566 					       sizeof(es->s_uuid));
3567 
3568 	/* Set defaults before we parse the mount options */
3569 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3570 	set_opt(sb, INIT_INODE_TABLE);
3571 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3572 		set_opt(sb, DEBUG);
3573 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3574 		set_opt(sb, GRPID);
3575 	if (def_mount_opts & EXT4_DEFM_UID16)
3576 		set_opt(sb, NO_UID32);
3577 	/* xattr user namespace & acls are now defaulted on */
3578 	set_opt(sb, XATTR_USER);
3579 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3580 	set_opt(sb, POSIX_ACL);
3581 #endif
3582 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3583 	if (ext4_has_metadata_csum(sb))
3584 		set_opt(sb, JOURNAL_CHECKSUM);
3585 
3586 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3587 		set_opt(sb, JOURNAL_DATA);
3588 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3589 		set_opt(sb, ORDERED_DATA);
3590 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3591 		set_opt(sb, WRITEBACK_DATA);
3592 
3593 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3594 		set_opt(sb, ERRORS_PANIC);
3595 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3596 		set_opt(sb, ERRORS_CONT);
3597 	else
3598 		set_opt(sb, ERRORS_RO);
3599 	/* block_validity enabled by default; disable with noblock_validity */
3600 	set_opt(sb, BLOCK_VALIDITY);
3601 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3602 		set_opt(sb, DISCARD);
3603 
3604 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3605 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3606 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3607 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3608 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3609 
3610 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3611 		set_opt(sb, BARRIER);
3612 
3613 	/*
3614 	 * enable delayed allocation by default
3615 	 * Use -o nodelalloc to turn it off
3616 	 */
3617 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3618 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3619 		set_opt(sb, DELALLOC);
3620 
3621 	/*
3622 	 * set default s_li_wait_mult for lazyinit, for the case there is
3623 	 * no mount option specified.
3624 	 */
3625 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3626 
3627 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3628 			   &journal_devnum, &journal_ioprio, 0)) {
3629 		ext4_msg(sb, KERN_WARNING,
3630 			 "failed to parse options in superblock: %s",
3631 			 sbi->s_es->s_mount_opts);
3632 	}
3633 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3634 	if (!parse_options((char *) data, sb, &journal_devnum,
3635 			   &journal_ioprio, 0))
3636 		goto failed_mount;
3637 
3638 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3639 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3640 			    "with data=journal disables delayed "
3641 			    "allocation and O_DIRECT support!\n");
3642 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3643 			ext4_msg(sb, KERN_ERR, "can't mount with "
3644 				 "both data=journal and delalloc");
3645 			goto failed_mount;
3646 		}
3647 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3648 			ext4_msg(sb, KERN_ERR, "can't mount with "
3649 				 "both data=journal and dioread_nolock");
3650 			goto failed_mount;
3651 		}
3652 		if (test_opt(sb, DAX)) {
3653 			ext4_msg(sb, KERN_ERR, "can't mount with "
3654 				 "both data=journal and dax");
3655 			goto failed_mount;
3656 		}
3657 		if (test_opt(sb, DELALLOC))
3658 			clear_opt(sb, DELALLOC);
3659 	} else {
3660 		sb->s_iflags |= SB_I_CGROUPWB;
3661 	}
3662 
3663 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3664 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3665 
3666 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3667 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3668 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3669 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3670 		ext4_msg(sb, KERN_WARNING,
3671 		       "feature flags set on rev 0 fs, "
3672 		       "running e2fsck is recommended");
3673 
3674 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3675 		set_opt2(sb, HURD_COMPAT);
3676 		if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3677 					      EXT4_FEATURE_INCOMPAT_64BIT)) {
3678 			ext4_msg(sb, KERN_ERR,
3679 				 "The Hurd can't support 64-bit file systems");
3680 			goto failed_mount;
3681 		}
3682 	}
3683 
3684 	if (IS_EXT2_SB(sb)) {
3685 		if (ext2_feature_set_ok(sb))
3686 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3687 				 "using the ext4 subsystem");
3688 		else {
3689 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3690 				 "to feature incompatibilities");
3691 			goto failed_mount;
3692 		}
3693 	}
3694 
3695 	if (IS_EXT3_SB(sb)) {
3696 		if (ext3_feature_set_ok(sb))
3697 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3698 				 "using the ext4 subsystem");
3699 		else {
3700 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3701 				 "to feature incompatibilities");
3702 			goto failed_mount;
3703 		}
3704 	}
3705 
3706 	/*
3707 	 * Check feature flags regardless of the revision level, since we
3708 	 * previously didn't change the revision level when setting the flags,
3709 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3710 	 */
3711 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3712 		goto failed_mount;
3713 
3714 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3715 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3716 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3717 		ext4_msg(sb, KERN_ERR,
3718 		       "Unsupported filesystem blocksize %d", blocksize);
3719 		goto failed_mount;
3720 	}
3721 
3722 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3723 		if (blocksize != PAGE_SIZE) {
3724 			ext4_msg(sb, KERN_ERR,
3725 					"error: unsupported blocksize for dax");
3726 			goto failed_mount;
3727 		}
3728 		if (!sb->s_bdev->bd_disk->fops->direct_access) {
3729 			ext4_msg(sb, KERN_ERR,
3730 					"error: device does not support dax");
3731 			goto failed_mount;
3732 		}
3733 	}
3734 
3735 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT) &&
3736 	    es->s_encryption_level) {
3737 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3738 			 es->s_encryption_level);
3739 		goto failed_mount;
3740 	}
3741 
3742 	if (sb->s_blocksize != blocksize) {
3743 		/* Validate the filesystem blocksize */
3744 		if (!sb_set_blocksize(sb, blocksize)) {
3745 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3746 					blocksize);
3747 			goto failed_mount;
3748 		}
3749 
3750 		brelse(bh);
3751 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3752 		offset = do_div(logical_sb_block, blocksize);
3753 		bh = sb_bread_unmovable(sb, logical_sb_block);
3754 		if (!bh) {
3755 			ext4_msg(sb, KERN_ERR,
3756 			       "Can't read superblock on 2nd try");
3757 			goto failed_mount;
3758 		}
3759 		es = (struct ext4_super_block *)(bh->b_data + offset);
3760 		sbi->s_es = es;
3761 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3762 			ext4_msg(sb, KERN_ERR,
3763 			       "Magic mismatch, very weird!");
3764 			goto failed_mount;
3765 		}
3766 	}
3767 
3768 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3769 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3770 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3771 						      has_huge_files);
3772 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3773 
3774 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3775 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3776 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3777 	} else {
3778 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3779 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3780 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3781 		    (!is_power_of_2(sbi->s_inode_size)) ||
3782 		    (sbi->s_inode_size > blocksize)) {
3783 			ext4_msg(sb, KERN_ERR,
3784 			       "unsupported inode size: %d",
3785 			       sbi->s_inode_size);
3786 			goto failed_mount;
3787 		}
3788 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3789 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3790 	}
3791 
3792 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3793 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3794 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3795 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3796 		    !is_power_of_2(sbi->s_desc_size)) {
3797 			ext4_msg(sb, KERN_ERR,
3798 			       "unsupported descriptor size %lu",
3799 			       sbi->s_desc_size);
3800 			goto failed_mount;
3801 		}
3802 	} else
3803 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3804 
3805 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3806 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3807 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3808 		goto cantfind_ext4;
3809 
3810 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3811 	if (sbi->s_inodes_per_block == 0)
3812 		goto cantfind_ext4;
3813 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3814 					sbi->s_inodes_per_block;
3815 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3816 	sbi->s_sbh = bh;
3817 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3818 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3819 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3820 
3821 	for (i = 0; i < 4; i++)
3822 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3823 	sbi->s_def_hash_version = es->s_def_hash_version;
3824 	if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3825 		i = le32_to_cpu(es->s_flags);
3826 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3827 			sbi->s_hash_unsigned = 3;
3828 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3829 #ifdef __CHAR_UNSIGNED__
3830 			if (!(sb->s_flags & MS_RDONLY))
3831 				es->s_flags |=
3832 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3833 			sbi->s_hash_unsigned = 3;
3834 #else
3835 			if (!(sb->s_flags & MS_RDONLY))
3836 				es->s_flags |=
3837 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3838 #endif
3839 		}
3840 	}
3841 
3842 	/* Handle clustersize */
3843 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3844 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3845 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3846 	if (has_bigalloc) {
3847 		if (clustersize < blocksize) {
3848 			ext4_msg(sb, KERN_ERR,
3849 				 "cluster size (%d) smaller than "
3850 				 "block size (%d)", clustersize, blocksize);
3851 			goto failed_mount;
3852 		}
3853 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3854 			le32_to_cpu(es->s_log_block_size);
3855 		sbi->s_clusters_per_group =
3856 			le32_to_cpu(es->s_clusters_per_group);
3857 		if (sbi->s_clusters_per_group > blocksize * 8) {
3858 			ext4_msg(sb, KERN_ERR,
3859 				 "#clusters per group too big: %lu",
3860 				 sbi->s_clusters_per_group);
3861 			goto failed_mount;
3862 		}
3863 		if (sbi->s_blocks_per_group !=
3864 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3865 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3866 				 "clusters per group (%lu) inconsistent",
3867 				 sbi->s_blocks_per_group,
3868 				 sbi->s_clusters_per_group);
3869 			goto failed_mount;
3870 		}
3871 	} else {
3872 		if (clustersize != blocksize) {
3873 			ext4_warning(sb, "fragment/cluster size (%d) != "
3874 				     "block size (%d)", clustersize,
3875 				     blocksize);
3876 			clustersize = blocksize;
3877 		}
3878 		if (sbi->s_blocks_per_group > blocksize * 8) {
3879 			ext4_msg(sb, KERN_ERR,
3880 				 "#blocks per group too big: %lu",
3881 				 sbi->s_blocks_per_group);
3882 			goto failed_mount;
3883 		}
3884 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3885 		sbi->s_cluster_bits = 0;
3886 	}
3887 	sbi->s_cluster_ratio = clustersize / blocksize;
3888 
3889 	if (sbi->s_inodes_per_group > blocksize * 8) {
3890 		ext4_msg(sb, KERN_ERR,
3891 		       "#inodes per group too big: %lu",
3892 		       sbi->s_inodes_per_group);
3893 		goto failed_mount;
3894 	}
3895 
3896 	/* Do we have standard group size of clustersize * 8 blocks ? */
3897 	if (sbi->s_blocks_per_group == clustersize << 3)
3898 		set_opt2(sb, STD_GROUP_SIZE);
3899 
3900 	/*
3901 	 * Test whether we have more sectors than will fit in sector_t,
3902 	 * and whether the max offset is addressable by the page cache.
3903 	 */
3904 	err = generic_check_addressable(sb->s_blocksize_bits,
3905 					ext4_blocks_count(es));
3906 	if (err) {
3907 		ext4_msg(sb, KERN_ERR, "filesystem"
3908 			 " too large to mount safely on this system");
3909 		if (sizeof(sector_t) < 8)
3910 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3911 		goto failed_mount;
3912 	}
3913 
3914 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3915 		goto cantfind_ext4;
3916 
3917 	/* check blocks count against device size */
3918 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3919 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3920 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3921 		       "exceeds size of device (%llu blocks)",
3922 		       ext4_blocks_count(es), blocks_count);
3923 		goto failed_mount;
3924 	}
3925 
3926 	/*
3927 	 * It makes no sense for the first data block to be beyond the end
3928 	 * of the filesystem.
3929 	 */
3930 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3931 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3932 			 "block %u is beyond end of filesystem (%llu)",
3933 			 le32_to_cpu(es->s_first_data_block),
3934 			 ext4_blocks_count(es));
3935 		goto failed_mount;
3936 	}
3937 	blocks_count = (ext4_blocks_count(es) -
3938 			le32_to_cpu(es->s_first_data_block) +
3939 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3940 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3941 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3942 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3943 		       "(block count %llu, first data block %u, "
3944 		       "blocks per group %lu)", sbi->s_groups_count,
3945 		       ext4_blocks_count(es),
3946 		       le32_to_cpu(es->s_first_data_block),
3947 		       EXT4_BLOCKS_PER_GROUP(sb));
3948 		goto failed_mount;
3949 	}
3950 	sbi->s_groups_count = blocks_count;
3951 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3952 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3953 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3954 		   EXT4_DESC_PER_BLOCK(sb);
3955 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3956 					  sizeof(struct buffer_head *),
3957 					  GFP_KERNEL);
3958 	if (sbi->s_group_desc == NULL) {
3959 		ext4_msg(sb, KERN_ERR, "not enough memory");
3960 		ret = -ENOMEM;
3961 		goto failed_mount;
3962 	}
3963 
3964 	if (ext4_proc_root)
3965 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3966 
3967 	if (sbi->s_proc)
3968 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3969 				 &ext4_seq_options_fops, sb);
3970 
3971 	bgl_lock_init(sbi->s_blockgroup_lock);
3972 
3973 	for (i = 0; i < db_count; i++) {
3974 		block = descriptor_loc(sb, logical_sb_block, i);
3975 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3976 		if (!sbi->s_group_desc[i]) {
3977 			ext4_msg(sb, KERN_ERR,
3978 			       "can't read group descriptor %d", i);
3979 			db_count = i;
3980 			goto failed_mount2;
3981 		}
3982 	}
3983 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3984 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3985 		goto failed_mount2;
3986 	}
3987 
3988 	sbi->s_gdb_count = db_count;
3989 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3990 	spin_lock_init(&sbi->s_next_gen_lock);
3991 
3992 	setup_timer(&sbi->s_err_report, print_daily_error_info,
3993 		(unsigned long) sb);
3994 
3995 	/* Register extent status tree shrinker */
3996 	if (ext4_es_register_shrinker(sbi))
3997 		goto failed_mount3;
3998 
3999 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4000 	sbi->s_extent_max_zeroout_kb = 32;
4001 
4002 	/*
4003 	 * set up enough so that it can read an inode
4004 	 */
4005 	sb->s_op = &ext4_sops;
4006 	sb->s_export_op = &ext4_export_ops;
4007 	sb->s_xattr = ext4_xattr_handlers;
4008 #ifdef CONFIG_QUOTA
4009 	sb->dq_op = &ext4_quota_operations;
4010 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
4011 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4012 	else
4013 		sb->s_qcop = &ext4_qctl_operations;
4014 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
4015 #endif
4016 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4017 
4018 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4019 	mutex_init(&sbi->s_orphan_lock);
4020 
4021 	sb->s_root = NULL;
4022 
4023 	needs_recovery = (es->s_last_orphan != 0 ||
4024 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
4025 				    EXT4_FEATURE_INCOMPAT_RECOVER));
4026 
4027 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
4028 	    !(sb->s_flags & MS_RDONLY))
4029 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4030 			goto failed_mount3a;
4031 
4032 	/*
4033 	 * The first inode we look at is the journal inode.  Don't try
4034 	 * root first: it may be modified in the journal!
4035 	 */
4036 	if (!test_opt(sb, NOLOAD) &&
4037 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4038 		if (ext4_load_journal(sb, es, journal_devnum))
4039 			goto failed_mount3a;
4040 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
4041 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4042 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4043 		       "suppressed and not mounted read-only");
4044 		goto failed_mount_wq;
4045 	} else {
4046 		clear_opt(sb, DATA_FLAGS);
4047 		sbi->s_journal = NULL;
4048 		needs_recovery = 0;
4049 		goto no_journal;
4050 	}
4051 
4052 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
4053 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4054 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4055 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4056 		goto failed_mount_wq;
4057 	}
4058 
4059 	if (!set_journal_csum_feature_set(sb)) {
4060 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4061 			 "feature set");
4062 		goto failed_mount_wq;
4063 	}
4064 
4065 	/* We have now updated the journal if required, so we can
4066 	 * validate the data journaling mode. */
4067 	switch (test_opt(sb, DATA_FLAGS)) {
4068 	case 0:
4069 		/* No mode set, assume a default based on the journal
4070 		 * capabilities: ORDERED_DATA if the journal can
4071 		 * cope, else JOURNAL_DATA
4072 		 */
4073 		if (jbd2_journal_check_available_features
4074 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4075 			set_opt(sb, ORDERED_DATA);
4076 		else
4077 			set_opt(sb, JOURNAL_DATA);
4078 		break;
4079 
4080 	case EXT4_MOUNT_ORDERED_DATA:
4081 	case EXT4_MOUNT_WRITEBACK_DATA:
4082 		if (!jbd2_journal_check_available_features
4083 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4084 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4085 			       "requested data journaling mode");
4086 			goto failed_mount_wq;
4087 		}
4088 	default:
4089 		break;
4090 	}
4091 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4092 
4093 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4094 
4095 no_journal:
4096 	if (ext4_mballoc_ready) {
4097 		sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4098 		if (!sbi->s_mb_cache) {
4099 			ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4100 			goto failed_mount_wq;
4101 		}
4102 	}
4103 
4104 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) ||
4105 	     EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT)) &&
4106 	    (blocksize != PAGE_CACHE_SIZE)) {
4107 		ext4_msg(sb, KERN_ERR,
4108 			 "Unsupported blocksize for fs encryption");
4109 		goto failed_mount_wq;
4110 	}
4111 
4112 	if (DUMMY_ENCRYPTION_ENABLED(sbi) &&
4113 	    !(sb->s_flags & MS_RDONLY) &&
4114 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT)) {
4115 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT);
4116 		ext4_commit_super(sb, 1);
4117 	}
4118 
4119 	/*
4120 	 * Get the # of file system overhead blocks from the
4121 	 * superblock if present.
4122 	 */
4123 	if (es->s_overhead_clusters)
4124 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4125 	else {
4126 		err = ext4_calculate_overhead(sb);
4127 		if (err)
4128 			goto failed_mount_wq;
4129 	}
4130 
4131 	/*
4132 	 * The maximum number of concurrent works can be high and
4133 	 * concurrency isn't really necessary.  Limit it to 1.
4134 	 */
4135 	EXT4_SB(sb)->rsv_conversion_wq =
4136 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4137 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4138 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4139 		ret = -ENOMEM;
4140 		goto failed_mount4;
4141 	}
4142 
4143 	/*
4144 	 * The jbd2_journal_load will have done any necessary log recovery,
4145 	 * so we can safely mount the rest of the filesystem now.
4146 	 */
4147 
4148 	root = ext4_iget(sb, EXT4_ROOT_INO);
4149 	if (IS_ERR(root)) {
4150 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4151 		ret = PTR_ERR(root);
4152 		root = NULL;
4153 		goto failed_mount4;
4154 	}
4155 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4156 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4157 		iput(root);
4158 		goto failed_mount4;
4159 	}
4160 	sb->s_root = d_make_root(root);
4161 	if (!sb->s_root) {
4162 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4163 		ret = -ENOMEM;
4164 		goto failed_mount4;
4165 	}
4166 
4167 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4168 		sb->s_flags |= MS_RDONLY;
4169 
4170 	/* determine the minimum size of new large inodes, if present */
4171 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4172 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4173 						     EXT4_GOOD_OLD_INODE_SIZE;
4174 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4175 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4176 			if (sbi->s_want_extra_isize <
4177 			    le16_to_cpu(es->s_want_extra_isize))
4178 				sbi->s_want_extra_isize =
4179 					le16_to_cpu(es->s_want_extra_isize);
4180 			if (sbi->s_want_extra_isize <
4181 			    le16_to_cpu(es->s_min_extra_isize))
4182 				sbi->s_want_extra_isize =
4183 					le16_to_cpu(es->s_min_extra_isize);
4184 		}
4185 	}
4186 	/* Check if enough inode space is available */
4187 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4188 							sbi->s_inode_size) {
4189 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4190 						       EXT4_GOOD_OLD_INODE_SIZE;
4191 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4192 			 "available");
4193 	}
4194 
4195 	err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4196 	if (err) {
4197 		ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4198 			 "reserved pool", ext4_calculate_resv_clusters(sb));
4199 		goto failed_mount4a;
4200 	}
4201 
4202 	err = ext4_setup_system_zone(sb);
4203 	if (err) {
4204 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4205 			 "zone (%d)", err);
4206 		goto failed_mount4a;
4207 	}
4208 
4209 	ext4_ext_init(sb);
4210 	err = ext4_mb_init(sb);
4211 	if (err) {
4212 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4213 			 err);
4214 		goto failed_mount5;
4215 	}
4216 
4217 	block = ext4_count_free_clusters(sb);
4218 	ext4_free_blocks_count_set(sbi->s_es,
4219 				   EXT4_C2B(sbi, block));
4220 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4221 				  GFP_KERNEL);
4222 	if (!err) {
4223 		unsigned long freei = ext4_count_free_inodes(sb);
4224 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4225 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4226 					  GFP_KERNEL);
4227 	}
4228 	if (!err)
4229 		err = percpu_counter_init(&sbi->s_dirs_counter,
4230 					  ext4_count_dirs(sb), GFP_KERNEL);
4231 	if (!err)
4232 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4233 					  GFP_KERNEL);
4234 	if (err) {
4235 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4236 		goto failed_mount6;
4237 	}
4238 
4239 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
4240 		if (!ext4_fill_flex_info(sb)) {
4241 			ext4_msg(sb, KERN_ERR,
4242 			       "unable to initialize "
4243 			       "flex_bg meta info!");
4244 			goto failed_mount6;
4245 		}
4246 
4247 	err = ext4_register_li_request(sb, first_not_zeroed);
4248 	if (err)
4249 		goto failed_mount6;
4250 
4251 	sbi->s_kobj.kset = ext4_kset;
4252 	init_completion(&sbi->s_kobj_unregister);
4253 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4254 				   "%s", sb->s_id);
4255 	if (err)
4256 		goto failed_mount7;
4257 
4258 #ifdef CONFIG_QUOTA
4259 	/* Enable quota usage during mount. */
4260 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4261 	    !(sb->s_flags & MS_RDONLY)) {
4262 		err = ext4_enable_quotas(sb);
4263 		if (err)
4264 			goto failed_mount8;
4265 	}
4266 #endif  /* CONFIG_QUOTA */
4267 
4268 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4269 	ext4_orphan_cleanup(sb, es);
4270 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4271 	if (needs_recovery) {
4272 		ext4_msg(sb, KERN_INFO, "recovery complete");
4273 		ext4_mark_recovery_complete(sb, es);
4274 	}
4275 	if (EXT4_SB(sb)->s_journal) {
4276 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4277 			descr = " journalled data mode";
4278 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4279 			descr = " ordered data mode";
4280 		else
4281 			descr = " writeback data mode";
4282 	} else
4283 		descr = "out journal";
4284 
4285 	if (test_opt(sb, DISCARD)) {
4286 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4287 		if (!blk_queue_discard(q))
4288 			ext4_msg(sb, KERN_WARNING,
4289 				 "mounting with \"discard\" option, but "
4290 				 "the device does not support discard");
4291 	}
4292 
4293 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4294 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4295 			 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4296 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4297 
4298 	if (es->s_error_count)
4299 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4300 
4301 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4302 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4303 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4304 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4305 
4306 	kfree(orig_data);
4307 	return 0;
4308 
4309 cantfind_ext4:
4310 	if (!silent)
4311 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4312 	goto failed_mount;
4313 
4314 #ifdef CONFIG_QUOTA
4315 failed_mount8:
4316 	kobject_del(&sbi->s_kobj);
4317 #endif
4318 failed_mount7:
4319 	ext4_unregister_li_request(sb);
4320 failed_mount6:
4321 	ext4_mb_release(sb);
4322 	if (sbi->s_flex_groups)
4323 		kvfree(sbi->s_flex_groups);
4324 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4325 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4326 	percpu_counter_destroy(&sbi->s_dirs_counter);
4327 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4328 failed_mount5:
4329 	ext4_ext_release(sb);
4330 	ext4_release_system_zone(sb);
4331 failed_mount4a:
4332 	dput(sb->s_root);
4333 	sb->s_root = NULL;
4334 failed_mount4:
4335 	ext4_msg(sb, KERN_ERR, "mount failed");
4336 	if (EXT4_SB(sb)->rsv_conversion_wq)
4337 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4338 failed_mount_wq:
4339 	if (sbi->s_journal) {
4340 		jbd2_journal_destroy(sbi->s_journal);
4341 		sbi->s_journal = NULL;
4342 	}
4343 failed_mount3a:
4344 	ext4_es_unregister_shrinker(sbi);
4345 failed_mount3:
4346 	del_timer_sync(&sbi->s_err_report);
4347 	if (sbi->s_mmp_tsk)
4348 		kthread_stop(sbi->s_mmp_tsk);
4349 failed_mount2:
4350 	for (i = 0; i < db_count; i++)
4351 		brelse(sbi->s_group_desc[i]);
4352 	kvfree(sbi->s_group_desc);
4353 failed_mount:
4354 	if (sbi->s_chksum_driver)
4355 		crypto_free_shash(sbi->s_chksum_driver);
4356 	if (sbi->s_proc) {
4357 		remove_proc_entry("options", sbi->s_proc);
4358 		remove_proc_entry(sb->s_id, ext4_proc_root);
4359 	}
4360 #ifdef CONFIG_QUOTA
4361 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4362 		kfree(sbi->s_qf_names[i]);
4363 #endif
4364 	ext4_blkdev_remove(sbi);
4365 	brelse(bh);
4366 out_fail:
4367 	sb->s_fs_info = NULL;
4368 	kfree(sbi->s_blockgroup_lock);
4369 	kfree(sbi);
4370 out_free_orig:
4371 	kfree(orig_data);
4372 	return err ? err : ret;
4373 }
4374 
4375 /*
4376  * Setup any per-fs journal parameters now.  We'll do this both on
4377  * initial mount, once the journal has been initialised but before we've
4378  * done any recovery; and again on any subsequent remount.
4379  */
4380 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4381 {
4382 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4383 
4384 	journal->j_commit_interval = sbi->s_commit_interval;
4385 	journal->j_min_batch_time = sbi->s_min_batch_time;
4386 	journal->j_max_batch_time = sbi->s_max_batch_time;
4387 
4388 	write_lock(&journal->j_state_lock);
4389 	if (test_opt(sb, BARRIER))
4390 		journal->j_flags |= JBD2_BARRIER;
4391 	else
4392 		journal->j_flags &= ~JBD2_BARRIER;
4393 	if (test_opt(sb, DATA_ERR_ABORT))
4394 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4395 	else
4396 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4397 	write_unlock(&journal->j_state_lock);
4398 }
4399 
4400 static journal_t *ext4_get_journal(struct super_block *sb,
4401 				   unsigned int journal_inum)
4402 {
4403 	struct inode *journal_inode;
4404 	journal_t *journal;
4405 
4406 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4407 
4408 	/* First, test for the existence of a valid inode on disk.  Bad
4409 	 * things happen if we iget() an unused inode, as the subsequent
4410 	 * iput() will try to delete it. */
4411 
4412 	journal_inode = ext4_iget(sb, journal_inum);
4413 	if (IS_ERR(journal_inode)) {
4414 		ext4_msg(sb, KERN_ERR, "no journal found");
4415 		return NULL;
4416 	}
4417 	if (!journal_inode->i_nlink) {
4418 		make_bad_inode(journal_inode);
4419 		iput(journal_inode);
4420 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4421 		return NULL;
4422 	}
4423 
4424 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4425 		  journal_inode, journal_inode->i_size);
4426 	if (!S_ISREG(journal_inode->i_mode)) {
4427 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4428 		iput(journal_inode);
4429 		return NULL;
4430 	}
4431 
4432 	journal = jbd2_journal_init_inode(journal_inode);
4433 	if (!journal) {
4434 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4435 		iput(journal_inode);
4436 		return NULL;
4437 	}
4438 	journal->j_private = sb;
4439 	ext4_init_journal_params(sb, journal);
4440 	return journal;
4441 }
4442 
4443 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4444 				       dev_t j_dev)
4445 {
4446 	struct buffer_head *bh;
4447 	journal_t *journal;
4448 	ext4_fsblk_t start;
4449 	ext4_fsblk_t len;
4450 	int hblock, blocksize;
4451 	ext4_fsblk_t sb_block;
4452 	unsigned long offset;
4453 	struct ext4_super_block *es;
4454 	struct block_device *bdev;
4455 
4456 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4457 
4458 	bdev = ext4_blkdev_get(j_dev, sb);
4459 	if (bdev == NULL)
4460 		return NULL;
4461 
4462 	blocksize = sb->s_blocksize;
4463 	hblock = bdev_logical_block_size(bdev);
4464 	if (blocksize < hblock) {
4465 		ext4_msg(sb, KERN_ERR,
4466 			"blocksize too small for journal device");
4467 		goto out_bdev;
4468 	}
4469 
4470 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4471 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4472 	set_blocksize(bdev, blocksize);
4473 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4474 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4475 		       "external journal");
4476 		goto out_bdev;
4477 	}
4478 
4479 	es = (struct ext4_super_block *) (bh->b_data + offset);
4480 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4481 	    !(le32_to_cpu(es->s_feature_incompat) &
4482 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4483 		ext4_msg(sb, KERN_ERR, "external journal has "
4484 					"bad superblock");
4485 		brelse(bh);
4486 		goto out_bdev;
4487 	}
4488 
4489 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4490 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4491 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4492 		ext4_msg(sb, KERN_ERR, "external journal has "
4493 				       "corrupt superblock");
4494 		brelse(bh);
4495 		goto out_bdev;
4496 	}
4497 
4498 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4499 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4500 		brelse(bh);
4501 		goto out_bdev;
4502 	}
4503 
4504 	len = ext4_blocks_count(es);
4505 	start = sb_block + 1;
4506 	brelse(bh);	/* we're done with the superblock */
4507 
4508 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4509 					start, len, blocksize);
4510 	if (!journal) {
4511 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4512 		goto out_bdev;
4513 	}
4514 	journal->j_private = sb;
4515 	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4516 	wait_on_buffer(journal->j_sb_buffer);
4517 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4518 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4519 		goto out_journal;
4520 	}
4521 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4522 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4523 					"user (unsupported) - %d",
4524 			be32_to_cpu(journal->j_superblock->s_nr_users));
4525 		goto out_journal;
4526 	}
4527 	EXT4_SB(sb)->journal_bdev = bdev;
4528 	ext4_init_journal_params(sb, journal);
4529 	return journal;
4530 
4531 out_journal:
4532 	jbd2_journal_destroy(journal);
4533 out_bdev:
4534 	ext4_blkdev_put(bdev);
4535 	return NULL;
4536 }
4537 
4538 static int ext4_load_journal(struct super_block *sb,
4539 			     struct ext4_super_block *es,
4540 			     unsigned long journal_devnum)
4541 {
4542 	journal_t *journal;
4543 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4544 	dev_t journal_dev;
4545 	int err = 0;
4546 	int really_read_only;
4547 
4548 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4549 
4550 	if (journal_devnum &&
4551 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4552 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4553 			"numbers have changed");
4554 		journal_dev = new_decode_dev(journal_devnum);
4555 	} else
4556 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4557 
4558 	really_read_only = bdev_read_only(sb->s_bdev);
4559 
4560 	/*
4561 	 * Are we loading a blank journal or performing recovery after a
4562 	 * crash?  For recovery, we need to check in advance whether we
4563 	 * can get read-write access to the device.
4564 	 */
4565 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4566 		if (sb->s_flags & MS_RDONLY) {
4567 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4568 					"required on readonly filesystem");
4569 			if (really_read_only) {
4570 				ext4_msg(sb, KERN_ERR, "write access "
4571 					"unavailable, cannot proceed");
4572 				return -EROFS;
4573 			}
4574 			ext4_msg(sb, KERN_INFO, "write access will "
4575 			       "be enabled during recovery");
4576 		}
4577 	}
4578 
4579 	if (journal_inum && journal_dev) {
4580 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4581 		       "and inode journals!");
4582 		return -EINVAL;
4583 	}
4584 
4585 	if (journal_inum) {
4586 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4587 			return -EINVAL;
4588 	} else {
4589 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4590 			return -EINVAL;
4591 	}
4592 
4593 	if (!(journal->j_flags & JBD2_BARRIER))
4594 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4595 
4596 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4597 		err = jbd2_journal_wipe(journal, !really_read_only);
4598 	if (!err) {
4599 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4600 		if (save)
4601 			memcpy(save, ((char *) es) +
4602 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4603 		err = jbd2_journal_load(journal);
4604 		if (save)
4605 			memcpy(((char *) es) + EXT4_S_ERR_START,
4606 			       save, EXT4_S_ERR_LEN);
4607 		kfree(save);
4608 	}
4609 
4610 	if (err) {
4611 		ext4_msg(sb, KERN_ERR, "error loading journal");
4612 		jbd2_journal_destroy(journal);
4613 		return err;
4614 	}
4615 
4616 	EXT4_SB(sb)->s_journal = journal;
4617 	ext4_clear_journal_err(sb, es);
4618 
4619 	if (!really_read_only && journal_devnum &&
4620 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4621 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4622 
4623 		/* Make sure we flush the recovery flag to disk. */
4624 		ext4_commit_super(sb, 1);
4625 	}
4626 
4627 	return 0;
4628 }
4629 
4630 static int ext4_commit_super(struct super_block *sb, int sync)
4631 {
4632 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4633 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4634 	int error = 0;
4635 
4636 	if (!sbh || block_device_ejected(sb))
4637 		return error;
4638 	if (buffer_write_io_error(sbh)) {
4639 		/*
4640 		 * Oh, dear.  A previous attempt to write the
4641 		 * superblock failed.  This could happen because the
4642 		 * USB device was yanked out.  Or it could happen to
4643 		 * be a transient write error and maybe the block will
4644 		 * be remapped.  Nothing we can do but to retry the
4645 		 * write and hope for the best.
4646 		 */
4647 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4648 		       "superblock detected");
4649 		clear_buffer_write_io_error(sbh);
4650 		set_buffer_uptodate(sbh);
4651 	}
4652 	/*
4653 	 * If the file system is mounted read-only, don't update the
4654 	 * superblock write time.  This avoids updating the superblock
4655 	 * write time when we are mounting the root file system
4656 	 * read/only but we need to replay the journal; at that point,
4657 	 * for people who are east of GMT and who make their clock
4658 	 * tick in localtime for Windows bug-for-bug compatibility,
4659 	 * the clock is set in the future, and this will cause e2fsck
4660 	 * to complain and force a full file system check.
4661 	 */
4662 	if (!(sb->s_flags & MS_RDONLY))
4663 		es->s_wtime = cpu_to_le32(get_seconds());
4664 	if (sb->s_bdev->bd_part)
4665 		es->s_kbytes_written =
4666 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4667 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4668 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4669 	else
4670 		es->s_kbytes_written =
4671 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4672 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4673 		ext4_free_blocks_count_set(es,
4674 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4675 				&EXT4_SB(sb)->s_freeclusters_counter)));
4676 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4677 		es->s_free_inodes_count =
4678 			cpu_to_le32(percpu_counter_sum_positive(
4679 				&EXT4_SB(sb)->s_freeinodes_counter));
4680 	BUFFER_TRACE(sbh, "marking dirty");
4681 	ext4_superblock_csum_set(sb);
4682 	mark_buffer_dirty(sbh);
4683 	if (sync) {
4684 		error = __sync_dirty_buffer(sbh,
4685 			test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
4686 		if (error)
4687 			return error;
4688 
4689 		error = buffer_write_io_error(sbh);
4690 		if (error) {
4691 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4692 			       "superblock");
4693 			clear_buffer_write_io_error(sbh);
4694 			set_buffer_uptodate(sbh);
4695 		}
4696 	}
4697 	return error;
4698 }
4699 
4700 /*
4701  * Have we just finished recovery?  If so, and if we are mounting (or
4702  * remounting) the filesystem readonly, then we will end up with a
4703  * consistent fs on disk.  Record that fact.
4704  */
4705 static void ext4_mark_recovery_complete(struct super_block *sb,
4706 					struct ext4_super_block *es)
4707 {
4708 	journal_t *journal = EXT4_SB(sb)->s_journal;
4709 
4710 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4711 		BUG_ON(journal != NULL);
4712 		return;
4713 	}
4714 	jbd2_journal_lock_updates(journal);
4715 	if (jbd2_journal_flush(journal) < 0)
4716 		goto out;
4717 
4718 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4719 	    sb->s_flags & MS_RDONLY) {
4720 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4721 		ext4_commit_super(sb, 1);
4722 	}
4723 
4724 out:
4725 	jbd2_journal_unlock_updates(journal);
4726 }
4727 
4728 /*
4729  * If we are mounting (or read-write remounting) a filesystem whose journal
4730  * has recorded an error from a previous lifetime, move that error to the
4731  * main filesystem now.
4732  */
4733 static void ext4_clear_journal_err(struct super_block *sb,
4734 				   struct ext4_super_block *es)
4735 {
4736 	journal_t *journal;
4737 	int j_errno;
4738 	const char *errstr;
4739 
4740 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4741 
4742 	journal = EXT4_SB(sb)->s_journal;
4743 
4744 	/*
4745 	 * Now check for any error status which may have been recorded in the
4746 	 * journal by a prior ext4_error() or ext4_abort()
4747 	 */
4748 
4749 	j_errno = jbd2_journal_errno(journal);
4750 	if (j_errno) {
4751 		char nbuf[16];
4752 
4753 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4754 		ext4_warning(sb, "Filesystem error recorded "
4755 			     "from previous mount: %s", errstr);
4756 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4757 
4758 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4759 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4760 		ext4_commit_super(sb, 1);
4761 
4762 		jbd2_journal_clear_err(journal);
4763 		jbd2_journal_update_sb_errno(journal);
4764 	}
4765 }
4766 
4767 /*
4768  * Force the running and committing transactions to commit,
4769  * and wait on the commit.
4770  */
4771 int ext4_force_commit(struct super_block *sb)
4772 {
4773 	journal_t *journal;
4774 
4775 	if (sb->s_flags & MS_RDONLY)
4776 		return 0;
4777 
4778 	journal = EXT4_SB(sb)->s_journal;
4779 	return ext4_journal_force_commit(journal);
4780 }
4781 
4782 static int ext4_sync_fs(struct super_block *sb, int wait)
4783 {
4784 	int ret = 0;
4785 	tid_t target;
4786 	bool needs_barrier = false;
4787 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4788 
4789 	trace_ext4_sync_fs(sb, wait);
4790 	flush_workqueue(sbi->rsv_conversion_wq);
4791 	/*
4792 	 * Writeback quota in non-journalled quota case - journalled quota has
4793 	 * no dirty dquots
4794 	 */
4795 	dquot_writeback_dquots(sb, -1);
4796 	/*
4797 	 * Data writeback is possible w/o journal transaction, so barrier must
4798 	 * being sent at the end of the function. But we can skip it if
4799 	 * transaction_commit will do it for us.
4800 	 */
4801 	if (sbi->s_journal) {
4802 		target = jbd2_get_latest_transaction(sbi->s_journal);
4803 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4804 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4805 			needs_barrier = true;
4806 
4807 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4808 			if (wait)
4809 				ret = jbd2_log_wait_commit(sbi->s_journal,
4810 							   target);
4811 		}
4812 	} else if (wait && test_opt(sb, BARRIER))
4813 		needs_barrier = true;
4814 	if (needs_barrier) {
4815 		int err;
4816 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4817 		if (!ret)
4818 			ret = err;
4819 	}
4820 
4821 	return ret;
4822 }
4823 
4824 /*
4825  * LVM calls this function before a (read-only) snapshot is created.  This
4826  * gives us a chance to flush the journal completely and mark the fs clean.
4827  *
4828  * Note that only this function cannot bring a filesystem to be in a clean
4829  * state independently. It relies on upper layer to stop all data & metadata
4830  * modifications.
4831  */
4832 static int ext4_freeze(struct super_block *sb)
4833 {
4834 	int error = 0;
4835 	journal_t *journal;
4836 
4837 	if (sb->s_flags & MS_RDONLY)
4838 		return 0;
4839 
4840 	journal = EXT4_SB(sb)->s_journal;
4841 
4842 	if (journal) {
4843 		/* Now we set up the journal barrier. */
4844 		jbd2_journal_lock_updates(journal);
4845 
4846 		/*
4847 		 * Don't clear the needs_recovery flag if we failed to
4848 		 * flush the journal.
4849 		 */
4850 		error = jbd2_journal_flush(journal);
4851 		if (error < 0)
4852 			goto out;
4853 
4854 		/* Journal blocked and flushed, clear needs_recovery flag. */
4855 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4856 	}
4857 
4858 	error = ext4_commit_super(sb, 1);
4859 out:
4860 	if (journal)
4861 		/* we rely on upper layer to stop further updates */
4862 		jbd2_journal_unlock_updates(journal);
4863 	return error;
4864 }
4865 
4866 /*
4867  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4868  * flag here, even though the filesystem is not technically dirty yet.
4869  */
4870 static int ext4_unfreeze(struct super_block *sb)
4871 {
4872 	if (sb->s_flags & MS_RDONLY)
4873 		return 0;
4874 
4875 	if (EXT4_SB(sb)->s_journal) {
4876 		/* Reset the needs_recovery flag before the fs is unlocked. */
4877 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4878 	}
4879 
4880 	ext4_commit_super(sb, 1);
4881 	return 0;
4882 }
4883 
4884 /*
4885  * Structure to save mount options for ext4_remount's benefit
4886  */
4887 struct ext4_mount_options {
4888 	unsigned long s_mount_opt;
4889 	unsigned long s_mount_opt2;
4890 	kuid_t s_resuid;
4891 	kgid_t s_resgid;
4892 	unsigned long s_commit_interval;
4893 	u32 s_min_batch_time, s_max_batch_time;
4894 #ifdef CONFIG_QUOTA
4895 	int s_jquota_fmt;
4896 	char *s_qf_names[EXT4_MAXQUOTAS];
4897 #endif
4898 };
4899 
4900 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4901 {
4902 	struct ext4_super_block *es;
4903 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4904 	unsigned long old_sb_flags;
4905 	struct ext4_mount_options old_opts;
4906 	int enable_quota = 0;
4907 	ext4_group_t g;
4908 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4909 	int err = 0;
4910 #ifdef CONFIG_QUOTA
4911 	int i, j;
4912 #endif
4913 	char *orig_data = kstrdup(data, GFP_KERNEL);
4914 
4915 	/* Store the original options */
4916 	old_sb_flags = sb->s_flags;
4917 	old_opts.s_mount_opt = sbi->s_mount_opt;
4918 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4919 	old_opts.s_resuid = sbi->s_resuid;
4920 	old_opts.s_resgid = sbi->s_resgid;
4921 	old_opts.s_commit_interval = sbi->s_commit_interval;
4922 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4923 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4924 #ifdef CONFIG_QUOTA
4925 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4926 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4927 		if (sbi->s_qf_names[i]) {
4928 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4929 							 GFP_KERNEL);
4930 			if (!old_opts.s_qf_names[i]) {
4931 				for (j = 0; j < i; j++)
4932 					kfree(old_opts.s_qf_names[j]);
4933 				kfree(orig_data);
4934 				return -ENOMEM;
4935 			}
4936 		} else
4937 			old_opts.s_qf_names[i] = NULL;
4938 #endif
4939 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4940 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4941 
4942 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4943 		err = -EINVAL;
4944 		goto restore_opts;
4945 	}
4946 
4947 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4948 	    test_opt(sb, JOURNAL_CHECKSUM)) {
4949 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4950 			 "during remount not supported; ignoring");
4951 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4952 	}
4953 
4954 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4955 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4956 			ext4_msg(sb, KERN_ERR, "can't mount with "
4957 				 "both data=journal and delalloc");
4958 			err = -EINVAL;
4959 			goto restore_opts;
4960 		}
4961 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4962 			ext4_msg(sb, KERN_ERR, "can't mount with "
4963 				 "both data=journal and dioread_nolock");
4964 			err = -EINVAL;
4965 			goto restore_opts;
4966 		}
4967 		if (test_opt(sb, DAX)) {
4968 			ext4_msg(sb, KERN_ERR, "can't mount with "
4969 				 "both data=journal and dax");
4970 			err = -EINVAL;
4971 			goto restore_opts;
4972 		}
4973 	}
4974 
4975 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4976 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4977 			"dax flag with busy inodes while remounting");
4978 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4979 	}
4980 
4981 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4982 		ext4_abort(sb, "Abort forced by user");
4983 
4984 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4985 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4986 
4987 	es = sbi->s_es;
4988 
4989 	if (sbi->s_journal) {
4990 		ext4_init_journal_params(sb, sbi->s_journal);
4991 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4992 	}
4993 
4994 	if (*flags & MS_LAZYTIME)
4995 		sb->s_flags |= MS_LAZYTIME;
4996 
4997 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4998 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4999 			err = -EROFS;
5000 			goto restore_opts;
5001 		}
5002 
5003 		if (*flags & MS_RDONLY) {
5004 			err = sync_filesystem(sb);
5005 			if (err < 0)
5006 				goto restore_opts;
5007 			err = dquot_suspend(sb, -1);
5008 			if (err < 0)
5009 				goto restore_opts;
5010 
5011 			/*
5012 			 * First of all, the unconditional stuff we have to do
5013 			 * to disable replay of the journal when we next remount
5014 			 */
5015 			sb->s_flags |= MS_RDONLY;
5016 
5017 			/*
5018 			 * OK, test if we are remounting a valid rw partition
5019 			 * readonly, and if so set the rdonly flag and then
5020 			 * mark the partition as valid again.
5021 			 */
5022 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5023 			    (sbi->s_mount_state & EXT4_VALID_FS))
5024 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5025 
5026 			if (sbi->s_journal)
5027 				ext4_mark_recovery_complete(sb, es);
5028 		} else {
5029 			/* Make sure we can mount this feature set readwrite */
5030 			if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5031 					EXT4_FEATURE_RO_COMPAT_READONLY) ||
5032 			    !ext4_feature_set_ok(sb, 0)) {
5033 				err = -EROFS;
5034 				goto restore_opts;
5035 			}
5036 			/*
5037 			 * Make sure the group descriptor checksums
5038 			 * are sane.  If they aren't, refuse to remount r/w.
5039 			 */
5040 			for (g = 0; g < sbi->s_groups_count; g++) {
5041 				struct ext4_group_desc *gdp =
5042 					ext4_get_group_desc(sb, g, NULL);
5043 
5044 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5045 					ext4_msg(sb, KERN_ERR,
5046 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5047 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
5048 					       le16_to_cpu(gdp->bg_checksum));
5049 					err = -EINVAL;
5050 					goto restore_opts;
5051 				}
5052 			}
5053 
5054 			/*
5055 			 * If we have an unprocessed orphan list hanging
5056 			 * around from a previously readonly bdev mount,
5057 			 * require a full umount/remount for now.
5058 			 */
5059 			if (es->s_last_orphan) {
5060 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5061 				       "remount RDWR because of unprocessed "
5062 				       "orphan inode list.  Please "
5063 				       "umount/remount instead");
5064 				err = -EINVAL;
5065 				goto restore_opts;
5066 			}
5067 
5068 			/*
5069 			 * Mounting a RDONLY partition read-write, so reread
5070 			 * and store the current valid flag.  (It may have
5071 			 * been changed by e2fsck since we originally mounted
5072 			 * the partition.)
5073 			 */
5074 			if (sbi->s_journal)
5075 				ext4_clear_journal_err(sb, es);
5076 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5077 			if (!ext4_setup_super(sb, es, 0))
5078 				sb->s_flags &= ~MS_RDONLY;
5079 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
5080 						     EXT4_FEATURE_INCOMPAT_MMP))
5081 				if (ext4_multi_mount_protect(sb,
5082 						le64_to_cpu(es->s_mmp_block))) {
5083 					err = -EROFS;
5084 					goto restore_opts;
5085 				}
5086 			enable_quota = 1;
5087 		}
5088 	}
5089 
5090 	/*
5091 	 * Reinitialize lazy itable initialization thread based on
5092 	 * current settings
5093 	 */
5094 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5095 		ext4_unregister_li_request(sb);
5096 	else {
5097 		ext4_group_t first_not_zeroed;
5098 		first_not_zeroed = ext4_has_uninit_itable(sb);
5099 		ext4_register_li_request(sb, first_not_zeroed);
5100 	}
5101 
5102 	ext4_setup_system_zone(sb);
5103 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5104 		ext4_commit_super(sb, 1);
5105 
5106 #ifdef CONFIG_QUOTA
5107 	/* Release old quota file names */
5108 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5109 		kfree(old_opts.s_qf_names[i]);
5110 	if (enable_quota) {
5111 		if (sb_any_quota_suspended(sb))
5112 			dquot_resume(sb, -1);
5113 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5114 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
5115 			err = ext4_enable_quotas(sb);
5116 			if (err)
5117 				goto restore_opts;
5118 		}
5119 	}
5120 #endif
5121 
5122 	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5123 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5124 	kfree(orig_data);
5125 	return 0;
5126 
5127 restore_opts:
5128 	sb->s_flags = old_sb_flags;
5129 	sbi->s_mount_opt = old_opts.s_mount_opt;
5130 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5131 	sbi->s_resuid = old_opts.s_resuid;
5132 	sbi->s_resgid = old_opts.s_resgid;
5133 	sbi->s_commit_interval = old_opts.s_commit_interval;
5134 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5135 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5136 #ifdef CONFIG_QUOTA
5137 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5138 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5139 		kfree(sbi->s_qf_names[i]);
5140 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5141 	}
5142 #endif
5143 	kfree(orig_data);
5144 	return err;
5145 }
5146 
5147 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5148 {
5149 	struct super_block *sb = dentry->d_sb;
5150 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5151 	struct ext4_super_block *es = sbi->s_es;
5152 	ext4_fsblk_t overhead = 0, resv_blocks;
5153 	u64 fsid;
5154 	s64 bfree;
5155 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5156 
5157 	if (!test_opt(sb, MINIX_DF))
5158 		overhead = sbi->s_overhead;
5159 
5160 	buf->f_type = EXT4_SUPER_MAGIC;
5161 	buf->f_bsize = sb->s_blocksize;
5162 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5163 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5164 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5165 	/* prevent underflow in case that few free space is available */
5166 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5167 	buf->f_bavail = buf->f_bfree -
5168 			(ext4_r_blocks_count(es) + resv_blocks);
5169 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5170 		buf->f_bavail = 0;
5171 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5172 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5173 	buf->f_namelen = EXT4_NAME_LEN;
5174 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5175 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5176 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5177 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5178 
5179 	return 0;
5180 }
5181 
5182 /* Helper function for writing quotas on sync - we need to start transaction
5183  * before quota file is locked for write. Otherwise the are possible deadlocks:
5184  * Process 1                         Process 2
5185  * ext4_create()                     quota_sync()
5186  *   jbd2_journal_start()                  write_dquot()
5187  *   dquot_initialize()                         down(dqio_mutex)
5188  *     down(dqio_mutex)                    jbd2_journal_start()
5189  *
5190  */
5191 
5192 #ifdef CONFIG_QUOTA
5193 
5194 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5195 {
5196 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5197 }
5198 
5199 static int ext4_write_dquot(struct dquot *dquot)
5200 {
5201 	int ret, err;
5202 	handle_t *handle;
5203 	struct inode *inode;
5204 
5205 	inode = dquot_to_inode(dquot);
5206 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5207 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5208 	if (IS_ERR(handle))
5209 		return PTR_ERR(handle);
5210 	ret = dquot_commit(dquot);
5211 	err = ext4_journal_stop(handle);
5212 	if (!ret)
5213 		ret = err;
5214 	return ret;
5215 }
5216 
5217 static int ext4_acquire_dquot(struct dquot *dquot)
5218 {
5219 	int ret, err;
5220 	handle_t *handle;
5221 
5222 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5223 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5224 	if (IS_ERR(handle))
5225 		return PTR_ERR(handle);
5226 	ret = dquot_acquire(dquot);
5227 	err = ext4_journal_stop(handle);
5228 	if (!ret)
5229 		ret = err;
5230 	return ret;
5231 }
5232 
5233 static int ext4_release_dquot(struct dquot *dquot)
5234 {
5235 	int ret, err;
5236 	handle_t *handle;
5237 
5238 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5239 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5240 	if (IS_ERR(handle)) {
5241 		/* Release dquot anyway to avoid endless cycle in dqput() */
5242 		dquot_release(dquot);
5243 		return PTR_ERR(handle);
5244 	}
5245 	ret = dquot_release(dquot);
5246 	err = ext4_journal_stop(handle);
5247 	if (!ret)
5248 		ret = err;
5249 	return ret;
5250 }
5251 
5252 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5253 {
5254 	struct super_block *sb = dquot->dq_sb;
5255 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5256 
5257 	/* Are we journaling quotas? */
5258 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5259 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5260 		dquot_mark_dquot_dirty(dquot);
5261 		return ext4_write_dquot(dquot);
5262 	} else {
5263 		return dquot_mark_dquot_dirty(dquot);
5264 	}
5265 }
5266 
5267 static int ext4_write_info(struct super_block *sb, int type)
5268 {
5269 	int ret, err;
5270 	handle_t *handle;
5271 
5272 	/* Data block + inode block */
5273 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5274 	if (IS_ERR(handle))
5275 		return PTR_ERR(handle);
5276 	ret = dquot_commit_info(sb, type);
5277 	err = ext4_journal_stop(handle);
5278 	if (!ret)
5279 		ret = err;
5280 	return ret;
5281 }
5282 
5283 /*
5284  * Turn on quotas during mount time - we need to find
5285  * the quota file and such...
5286  */
5287 static int ext4_quota_on_mount(struct super_block *sb, int type)
5288 {
5289 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5290 					EXT4_SB(sb)->s_jquota_fmt, type);
5291 }
5292 
5293 /*
5294  * Standard function to be called on quota_on
5295  */
5296 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5297 			 struct path *path)
5298 {
5299 	int err;
5300 
5301 	if (!test_opt(sb, QUOTA))
5302 		return -EINVAL;
5303 
5304 	/* Quotafile not on the same filesystem? */
5305 	if (path->dentry->d_sb != sb)
5306 		return -EXDEV;
5307 	/* Journaling quota? */
5308 	if (EXT4_SB(sb)->s_qf_names[type]) {
5309 		/* Quotafile not in fs root? */
5310 		if (path->dentry->d_parent != sb->s_root)
5311 			ext4_msg(sb, KERN_WARNING,
5312 				"Quota file not on filesystem root. "
5313 				"Journaled quota will not work");
5314 	}
5315 
5316 	/*
5317 	 * When we journal data on quota file, we have to flush journal to see
5318 	 * all updates to the file when we bypass pagecache...
5319 	 */
5320 	if (EXT4_SB(sb)->s_journal &&
5321 	    ext4_should_journal_data(d_inode(path->dentry))) {
5322 		/*
5323 		 * We don't need to lock updates but journal_flush() could
5324 		 * otherwise be livelocked...
5325 		 */
5326 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5327 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5328 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5329 		if (err)
5330 			return err;
5331 	}
5332 
5333 	return dquot_quota_on(sb, type, format_id, path);
5334 }
5335 
5336 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5337 			     unsigned int flags)
5338 {
5339 	int err;
5340 	struct inode *qf_inode;
5341 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5342 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5343 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5344 	};
5345 
5346 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5347 
5348 	if (!qf_inums[type])
5349 		return -EPERM;
5350 
5351 	qf_inode = ext4_iget(sb, qf_inums[type]);
5352 	if (IS_ERR(qf_inode)) {
5353 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5354 		return PTR_ERR(qf_inode);
5355 	}
5356 
5357 	/* Don't account quota for quota files to avoid recursion */
5358 	qf_inode->i_flags |= S_NOQUOTA;
5359 	err = dquot_enable(qf_inode, type, format_id, flags);
5360 	iput(qf_inode);
5361 
5362 	return err;
5363 }
5364 
5365 /* Enable usage tracking for all quota types. */
5366 static int ext4_enable_quotas(struct super_block *sb)
5367 {
5368 	int type, err = 0;
5369 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5370 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5371 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5372 	};
5373 
5374 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5375 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5376 		if (qf_inums[type]) {
5377 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5378 						DQUOT_USAGE_ENABLED);
5379 			if (err) {
5380 				ext4_warning(sb,
5381 					"Failed to enable quota tracking "
5382 					"(type=%d, err=%d). Please run "
5383 					"e2fsck to fix.", type, err);
5384 				return err;
5385 			}
5386 		}
5387 	}
5388 	return 0;
5389 }
5390 
5391 static int ext4_quota_off(struct super_block *sb, int type)
5392 {
5393 	struct inode *inode = sb_dqopt(sb)->files[type];
5394 	handle_t *handle;
5395 
5396 	/* Force all delayed allocation blocks to be allocated.
5397 	 * Caller already holds s_umount sem */
5398 	if (test_opt(sb, DELALLOC))
5399 		sync_filesystem(sb);
5400 
5401 	if (!inode)
5402 		goto out;
5403 
5404 	/* Update modification times of quota files when userspace can
5405 	 * start looking at them */
5406 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5407 	if (IS_ERR(handle))
5408 		goto out;
5409 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5410 	ext4_mark_inode_dirty(handle, inode);
5411 	ext4_journal_stop(handle);
5412 
5413 out:
5414 	return dquot_quota_off(sb, type);
5415 }
5416 
5417 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5418  * acquiring the locks... As quota files are never truncated and quota code
5419  * itself serializes the operations (and no one else should touch the files)
5420  * we don't have to be afraid of races */
5421 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5422 			       size_t len, loff_t off)
5423 {
5424 	struct inode *inode = sb_dqopt(sb)->files[type];
5425 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5426 	int offset = off & (sb->s_blocksize - 1);
5427 	int tocopy;
5428 	size_t toread;
5429 	struct buffer_head *bh;
5430 	loff_t i_size = i_size_read(inode);
5431 
5432 	if (off > i_size)
5433 		return 0;
5434 	if (off+len > i_size)
5435 		len = i_size-off;
5436 	toread = len;
5437 	while (toread > 0) {
5438 		tocopy = sb->s_blocksize - offset < toread ?
5439 				sb->s_blocksize - offset : toread;
5440 		bh = ext4_bread(NULL, inode, blk, 0);
5441 		if (IS_ERR(bh))
5442 			return PTR_ERR(bh);
5443 		if (!bh)	/* A hole? */
5444 			memset(data, 0, tocopy);
5445 		else
5446 			memcpy(data, bh->b_data+offset, tocopy);
5447 		brelse(bh);
5448 		offset = 0;
5449 		toread -= tocopy;
5450 		data += tocopy;
5451 		blk++;
5452 	}
5453 	return len;
5454 }
5455 
5456 /* Write to quotafile (we know the transaction is already started and has
5457  * enough credits) */
5458 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5459 				const char *data, size_t len, loff_t off)
5460 {
5461 	struct inode *inode = sb_dqopt(sb)->files[type];
5462 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5463 	int err, offset = off & (sb->s_blocksize - 1);
5464 	int retries = 0;
5465 	struct buffer_head *bh;
5466 	handle_t *handle = journal_current_handle();
5467 
5468 	if (EXT4_SB(sb)->s_journal && !handle) {
5469 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5470 			" cancelled because transaction is not started",
5471 			(unsigned long long)off, (unsigned long long)len);
5472 		return -EIO;
5473 	}
5474 	/*
5475 	 * Since we account only one data block in transaction credits,
5476 	 * then it is impossible to cross a block boundary.
5477 	 */
5478 	if (sb->s_blocksize - offset < len) {
5479 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5480 			" cancelled because not block aligned",
5481 			(unsigned long long)off, (unsigned long long)len);
5482 		return -EIO;
5483 	}
5484 
5485 	do {
5486 		bh = ext4_bread(handle, inode, blk,
5487 				EXT4_GET_BLOCKS_CREATE |
5488 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5489 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5490 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5491 	if (IS_ERR(bh))
5492 		return PTR_ERR(bh);
5493 	if (!bh)
5494 		goto out;
5495 	BUFFER_TRACE(bh, "get write access");
5496 	err = ext4_journal_get_write_access(handle, bh);
5497 	if (err) {
5498 		brelse(bh);
5499 		return err;
5500 	}
5501 	lock_buffer(bh);
5502 	memcpy(bh->b_data+offset, data, len);
5503 	flush_dcache_page(bh->b_page);
5504 	unlock_buffer(bh);
5505 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5506 	brelse(bh);
5507 out:
5508 	if (inode->i_size < off + len) {
5509 		i_size_write(inode, off + len);
5510 		EXT4_I(inode)->i_disksize = inode->i_size;
5511 		ext4_mark_inode_dirty(handle, inode);
5512 	}
5513 	return len;
5514 }
5515 
5516 #endif
5517 
5518 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5519 		       const char *dev_name, void *data)
5520 {
5521 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5522 }
5523 
5524 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5525 static inline void register_as_ext2(void)
5526 {
5527 	int err = register_filesystem(&ext2_fs_type);
5528 	if (err)
5529 		printk(KERN_WARNING
5530 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5531 }
5532 
5533 static inline void unregister_as_ext2(void)
5534 {
5535 	unregister_filesystem(&ext2_fs_type);
5536 }
5537 
5538 static inline int ext2_feature_set_ok(struct super_block *sb)
5539 {
5540 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5541 		return 0;
5542 	if (sb->s_flags & MS_RDONLY)
5543 		return 1;
5544 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5545 		return 0;
5546 	return 1;
5547 }
5548 #else
5549 static inline void register_as_ext2(void) { }
5550 static inline void unregister_as_ext2(void) { }
5551 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5552 #endif
5553 
5554 static inline void register_as_ext3(void)
5555 {
5556 	int err = register_filesystem(&ext3_fs_type);
5557 	if (err)
5558 		printk(KERN_WARNING
5559 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5560 }
5561 
5562 static inline void unregister_as_ext3(void)
5563 {
5564 	unregister_filesystem(&ext3_fs_type);
5565 }
5566 
5567 static inline int ext3_feature_set_ok(struct super_block *sb)
5568 {
5569 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5570 		return 0;
5571 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5572 		return 0;
5573 	if (sb->s_flags & MS_RDONLY)
5574 		return 1;
5575 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5576 		return 0;
5577 	return 1;
5578 }
5579 
5580 static struct file_system_type ext4_fs_type = {
5581 	.owner		= THIS_MODULE,
5582 	.name		= "ext4",
5583 	.mount		= ext4_mount,
5584 	.kill_sb	= kill_block_super,
5585 	.fs_flags	= FS_REQUIRES_DEV,
5586 };
5587 MODULE_ALIAS_FS("ext4");
5588 
5589 static int __init ext4_init_feat_adverts(void)
5590 {
5591 	struct ext4_features *ef;
5592 	int ret = -ENOMEM;
5593 
5594 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5595 	if (!ef)
5596 		goto out;
5597 
5598 	ef->f_kobj.kset = ext4_kset;
5599 	init_completion(&ef->f_kobj_unregister);
5600 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5601 				   "features");
5602 	if (ret) {
5603 		kfree(ef);
5604 		goto out;
5605 	}
5606 
5607 	ext4_feat = ef;
5608 	ret = 0;
5609 out:
5610 	return ret;
5611 }
5612 
5613 static void ext4_exit_feat_adverts(void)
5614 {
5615 	kobject_put(&ext4_feat->f_kobj);
5616 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5617 	kfree(ext4_feat);
5618 }
5619 
5620 /* Shared across all ext4 file systems */
5621 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5622 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5623 
5624 static int __init ext4_init_fs(void)
5625 {
5626 	int i, err;
5627 
5628 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5629 	ext4_li_info = NULL;
5630 	mutex_init(&ext4_li_mtx);
5631 
5632 	/* Build-time check for flags consistency */
5633 	ext4_check_flag_values();
5634 
5635 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5636 		mutex_init(&ext4__aio_mutex[i]);
5637 		init_waitqueue_head(&ext4__ioend_wq[i]);
5638 	}
5639 
5640 	err = ext4_init_es();
5641 	if (err)
5642 		return err;
5643 
5644 	err = ext4_init_pageio();
5645 	if (err)
5646 		goto out7;
5647 
5648 	err = ext4_init_system_zone();
5649 	if (err)
5650 		goto out6;
5651 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5652 	if (!ext4_kset) {
5653 		err = -ENOMEM;
5654 		goto out5;
5655 	}
5656 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5657 
5658 	err = ext4_init_feat_adverts();
5659 	if (err)
5660 		goto out4;
5661 
5662 	err = ext4_init_mballoc();
5663 	if (err)
5664 		goto out2;
5665 	else
5666 		ext4_mballoc_ready = 1;
5667 	err = init_inodecache();
5668 	if (err)
5669 		goto out1;
5670 	register_as_ext3();
5671 	register_as_ext2();
5672 	err = register_filesystem(&ext4_fs_type);
5673 	if (err)
5674 		goto out;
5675 
5676 	return 0;
5677 out:
5678 	unregister_as_ext2();
5679 	unregister_as_ext3();
5680 	destroy_inodecache();
5681 out1:
5682 	ext4_mballoc_ready = 0;
5683 	ext4_exit_mballoc();
5684 out2:
5685 	ext4_exit_feat_adverts();
5686 out4:
5687 	if (ext4_proc_root)
5688 		remove_proc_entry("fs/ext4", NULL);
5689 	kset_unregister(ext4_kset);
5690 out5:
5691 	ext4_exit_system_zone();
5692 out6:
5693 	ext4_exit_pageio();
5694 out7:
5695 	ext4_exit_es();
5696 
5697 	return err;
5698 }
5699 
5700 static void __exit ext4_exit_fs(void)
5701 {
5702 	ext4_exit_crypto();
5703 	ext4_destroy_lazyinit_thread();
5704 	unregister_as_ext2();
5705 	unregister_as_ext3();
5706 	unregister_filesystem(&ext4_fs_type);
5707 	destroy_inodecache();
5708 	ext4_exit_mballoc();
5709 	ext4_exit_feat_adverts();
5710 	remove_proc_entry("fs/ext4", NULL);
5711 	kset_unregister(ext4_kset);
5712 	ext4_exit_system_zone();
5713 	ext4_exit_pageio();
5714 	ext4_exit_es();
5715 }
5716 
5717 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5718 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5719 MODULE_LICENSE("GPL");
5720 module_init(ext4_init_fs)
5721 module_exit(ext4_exit_fs)
5722