xref: /openbmc/linux/fs/ext4/super.c (revision bc000245)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/jbd2.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/parser.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/proc_fs.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/cleancache.h>
42 #include <asm/uaccess.h>
43 
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46 
47 #include "ext4.h"
48 #include "ext4_extents.h"	/* Needed for trace points definition */
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/ext4.h>
56 
57 static struct proc_dir_entry *ext4_proc_root;
58 static struct kset *ext4_kset;
59 static struct ext4_lazy_init *ext4_li_info;
60 static struct mutex ext4_li_mtx;
61 static struct ext4_features *ext4_feat;
62 
63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
64 			     unsigned long journal_devnum);
65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
66 static int ext4_commit_super(struct super_block *sb, int sync);
67 static void ext4_mark_recovery_complete(struct super_block *sb,
68 					struct ext4_super_block *es);
69 static void ext4_clear_journal_err(struct super_block *sb,
70 				   struct ext4_super_block *es);
71 static int ext4_sync_fs(struct super_block *sb, int wait);
72 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait);
73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
75 static int ext4_unfreeze(struct super_block *sb);
76 static int ext4_freeze(struct super_block *sb);
77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
78 		       const char *dev_name, void *data);
79 static inline int ext2_feature_set_ok(struct super_block *sb);
80 static inline int ext3_feature_set_ok(struct super_block *sb);
81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
86 
87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
88 static struct file_system_type ext2_fs_type = {
89 	.owner		= THIS_MODULE,
90 	.name		= "ext2",
91 	.mount		= ext4_mount,
92 	.kill_sb	= kill_block_super,
93 	.fs_flags	= FS_REQUIRES_DEV,
94 };
95 MODULE_ALIAS_FS("ext2");
96 MODULE_ALIAS("ext2");
97 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
98 #else
99 #define IS_EXT2_SB(sb) (0)
100 #endif
101 
102 
103 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
104 static struct file_system_type ext3_fs_type = {
105 	.owner		= THIS_MODULE,
106 	.name		= "ext3",
107 	.mount		= ext4_mount,
108 	.kill_sb	= kill_block_super,
109 	.fs_flags	= FS_REQUIRES_DEV,
110 };
111 MODULE_ALIAS_FS("ext3");
112 MODULE_ALIAS("ext3");
113 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
114 #else
115 #define IS_EXT3_SB(sb) (0)
116 #endif
117 
118 static int ext4_verify_csum_type(struct super_block *sb,
119 				 struct ext4_super_block *es)
120 {
121 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
122 					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
123 		return 1;
124 
125 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
126 }
127 
128 static __le32 ext4_superblock_csum(struct super_block *sb,
129 				   struct ext4_super_block *es)
130 {
131 	struct ext4_sb_info *sbi = EXT4_SB(sb);
132 	int offset = offsetof(struct ext4_super_block, s_checksum);
133 	__u32 csum;
134 
135 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
136 
137 	return cpu_to_le32(csum);
138 }
139 
140 int ext4_superblock_csum_verify(struct super_block *sb,
141 				struct ext4_super_block *es)
142 {
143 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
144 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
145 		return 1;
146 
147 	return es->s_checksum == ext4_superblock_csum(sb, es);
148 }
149 
150 void ext4_superblock_csum_set(struct super_block *sb)
151 {
152 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
153 
154 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
155 		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
156 		return;
157 
158 	es->s_checksum = ext4_superblock_csum(sb, es);
159 }
160 
161 void *ext4_kvmalloc(size_t size, gfp_t flags)
162 {
163 	void *ret;
164 
165 	ret = kmalloc(size, flags | __GFP_NOWARN);
166 	if (!ret)
167 		ret = __vmalloc(size, flags, PAGE_KERNEL);
168 	return ret;
169 }
170 
171 void *ext4_kvzalloc(size_t size, gfp_t flags)
172 {
173 	void *ret;
174 
175 	ret = kzalloc(size, flags | __GFP_NOWARN);
176 	if (!ret)
177 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
178 	return ret;
179 }
180 
181 void ext4_kvfree(void *ptr)
182 {
183 	if (is_vmalloc_addr(ptr))
184 		vfree(ptr);
185 	else
186 		kfree(ptr);
187 
188 }
189 
190 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
191 			       struct ext4_group_desc *bg)
192 {
193 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
194 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
195 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
196 }
197 
198 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
199 			       struct ext4_group_desc *bg)
200 {
201 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
202 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
203 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
204 }
205 
206 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
207 			      struct ext4_group_desc *bg)
208 {
209 	return le32_to_cpu(bg->bg_inode_table_lo) |
210 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
211 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
212 }
213 
214 __u32 ext4_free_group_clusters(struct super_block *sb,
215 			       struct ext4_group_desc *bg)
216 {
217 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
218 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
219 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
220 }
221 
222 __u32 ext4_free_inodes_count(struct super_block *sb,
223 			      struct ext4_group_desc *bg)
224 {
225 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
226 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
227 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
228 }
229 
230 __u32 ext4_used_dirs_count(struct super_block *sb,
231 			      struct ext4_group_desc *bg)
232 {
233 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
234 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
235 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
236 }
237 
238 __u32 ext4_itable_unused_count(struct super_block *sb,
239 			      struct ext4_group_desc *bg)
240 {
241 	return le16_to_cpu(bg->bg_itable_unused_lo) |
242 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
243 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
244 }
245 
246 void ext4_block_bitmap_set(struct super_block *sb,
247 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
248 {
249 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
250 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
251 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
252 }
253 
254 void ext4_inode_bitmap_set(struct super_block *sb,
255 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
256 {
257 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
258 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
259 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
260 }
261 
262 void ext4_inode_table_set(struct super_block *sb,
263 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
264 {
265 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
266 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
267 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
268 }
269 
270 void ext4_free_group_clusters_set(struct super_block *sb,
271 				  struct ext4_group_desc *bg, __u32 count)
272 {
273 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
274 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
275 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
276 }
277 
278 void ext4_free_inodes_set(struct super_block *sb,
279 			  struct ext4_group_desc *bg, __u32 count)
280 {
281 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
282 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
283 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
284 }
285 
286 void ext4_used_dirs_set(struct super_block *sb,
287 			  struct ext4_group_desc *bg, __u32 count)
288 {
289 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
290 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
291 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
292 }
293 
294 void ext4_itable_unused_set(struct super_block *sb,
295 			  struct ext4_group_desc *bg, __u32 count)
296 {
297 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
298 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
299 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
300 }
301 
302 
303 static void __save_error_info(struct super_block *sb, const char *func,
304 			    unsigned int line)
305 {
306 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
307 
308 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
309 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
310 	es->s_last_error_time = cpu_to_le32(get_seconds());
311 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
312 	es->s_last_error_line = cpu_to_le32(line);
313 	if (!es->s_first_error_time) {
314 		es->s_first_error_time = es->s_last_error_time;
315 		strncpy(es->s_first_error_func, func,
316 			sizeof(es->s_first_error_func));
317 		es->s_first_error_line = cpu_to_le32(line);
318 		es->s_first_error_ino = es->s_last_error_ino;
319 		es->s_first_error_block = es->s_last_error_block;
320 	}
321 	/*
322 	 * Start the daily error reporting function if it hasn't been
323 	 * started already
324 	 */
325 	if (!es->s_error_count)
326 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
327 	le32_add_cpu(&es->s_error_count, 1);
328 }
329 
330 static void save_error_info(struct super_block *sb, const char *func,
331 			    unsigned int line)
332 {
333 	__save_error_info(sb, func, line);
334 	ext4_commit_super(sb, 1);
335 }
336 
337 /*
338  * The del_gendisk() function uninitializes the disk-specific data
339  * structures, including the bdi structure, without telling anyone
340  * else.  Once this happens, any attempt to call mark_buffer_dirty()
341  * (for example, by ext4_commit_super), will cause a kernel OOPS.
342  * This is a kludge to prevent these oops until we can put in a proper
343  * hook in del_gendisk() to inform the VFS and file system layers.
344  */
345 static int block_device_ejected(struct super_block *sb)
346 {
347 	struct inode *bd_inode = sb->s_bdev->bd_inode;
348 	struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
349 
350 	return bdi->dev == NULL;
351 }
352 
353 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
354 {
355 	struct super_block		*sb = journal->j_private;
356 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
357 	int				error = is_journal_aborted(journal);
358 	struct ext4_journal_cb_entry	*jce;
359 
360 	BUG_ON(txn->t_state == T_FINISHED);
361 	spin_lock(&sbi->s_md_lock);
362 	while (!list_empty(&txn->t_private_list)) {
363 		jce = list_entry(txn->t_private_list.next,
364 				 struct ext4_journal_cb_entry, jce_list);
365 		list_del_init(&jce->jce_list);
366 		spin_unlock(&sbi->s_md_lock);
367 		jce->jce_func(sb, jce, error);
368 		spin_lock(&sbi->s_md_lock);
369 	}
370 	spin_unlock(&sbi->s_md_lock);
371 }
372 
373 /* Deal with the reporting of failure conditions on a filesystem such as
374  * inconsistencies detected or read IO failures.
375  *
376  * On ext2, we can store the error state of the filesystem in the
377  * superblock.  That is not possible on ext4, because we may have other
378  * write ordering constraints on the superblock which prevent us from
379  * writing it out straight away; and given that the journal is about to
380  * be aborted, we can't rely on the current, or future, transactions to
381  * write out the superblock safely.
382  *
383  * We'll just use the jbd2_journal_abort() error code to record an error in
384  * the journal instead.  On recovery, the journal will complain about
385  * that error until we've noted it down and cleared it.
386  */
387 
388 static void ext4_handle_error(struct super_block *sb)
389 {
390 	if (sb->s_flags & MS_RDONLY)
391 		return;
392 
393 	if (!test_opt(sb, ERRORS_CONT)) {
394 		journal_t *journal = EXT4_SB(sb)->s_journal;
395 
396 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
397 		if (journal)
398 			jbd2_journal_abort(journal, -EIO);
399 	}
400 	if (test_opt(sb, ERRORS_RO)) {
401 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
402 		/*
403 		 * Make sure updated value of ->s_mount_flags will be visible
404 		 * before ->s_flags update
405 		 */
406 		smp_wmb();
407 		sb->s_flags |= MS_RDONLY;
408 	}
409 	if (test_opt(sb, ERRORS_PANIC))
410 		panic("EXT4-fs (device %s): panic forced after error\n",
411 			sb->s_id);
412 }
413 
414 #define ext4_error_ratelimit(sb)					\
415 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
416 			     "EXT4-fs error")
417 
418 void __ext4_error(struct super_block *sb, const char *function,
419 		  unsigned int line, const char *fmt, ...)
420 {
421 	struct va_format vaf;
422 	va_list args;
423 
424 	if (ext4_error_ratelimit(sb)) {
425 		va_start(args, fmt);
426 		vaf.fmt = fmt;
427 		vaf.va = &args;
428 		printk(KERN_CRIT
429 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
430 		       sb->s_id, function, line, current->comm, &vaf);
431 		va_end(args);
432 	}
433 	save_error_info(sb, function, line);
434 	ext4_handle_error(sb);
435 }
436 
437 void __ext4_error_inode(struct inode *inode, const char *function,
438 			unsigned int line, ext4_fsblk_t block,
439 			const char *fmt, ...)
440 {
441 	va_list args;
442 	struct va_format vaf;
443 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
444 
445 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
446 	es->s_last_error_block = cpu_to_le64(block);
447 	if (ext4_error_ratelimit(inode->i_sb)) {
448 		va_start(args, fmt);
449 		vaf.fmt = fmt;
450 		vaf.va = &args;
451 		if (block)
452 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
453 			       "inode #%lu: block %llu: comm %s: %pV\n",
454 			       inode->i_sb->s_id, function, line, inode->i_ino,
455 			       block, current->comm, &vaf);
456 		else
457 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
458 			       "inode #%lu: comm %s: %pV\n",
459 			       inode->i_sb->s_id, function, line, inode->i_ino,
460 			       current->comm, &vaf);
461 		va_end(args);
462 	}
463 	save_error_info(inode->i_sb, function, line);
464 	ext4_handle_error(inode->i_sb);
465 }
466 
467 void __ext4_error_file(struct file *file, const char *function,
468 		       unsigned int line, ext4_fsblk_t block,
469 		       const char *fmt, ...)
470 {
471 	va_list args;
472 	struct va_format vaf;
473 	struct ext4_super_block *es;
474 	struct inode *inode = file_inode(file);
475 	char pathname[80], *path;
476 
477 	es = EXT4_SB(inode->i_sb)->s_es;
478 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
479 	if (ext4_error_ratelimit(inode->i_sb)) {
480 		path = d_path(&(file->f_path), pathname, sizeof(pathname));
481 		if (IS_ERR(path))
482 			path = "(unknown)";
483 		va_start(args, fmt);
484 		vaf.fmt = fmt;
485 		vaf.va = &args;
486 		if (block)
487 			printk(KERN_CRIT
488 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
489 			       "block %llu: comm %s: path %s: %pV\n",
490 			       inode->i_sb->s_id, function, line, inode->i_ino,
491 			       block, current->comm, path, &vaf);
492 		else
493 			printk(KERN_CRIT
494 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
495 			       "comm %s: path %s: %pV\n",
496 			       inode->i_sb->s_id, function, line, inode->i_ino,
497 			       current->comm, path, &vaf);
498 		va_end(args);
499 	}
500 	save_error_info(inode->i_sb, function, line);
501 	ext4_handle_error(inode->i_sb);
502 }
503 
504 const char *ext4_decode_error(struct super_block *sb, int errno,
505 			      char nbuf[16])
506 {
507 	char *errstr = NULL;
508 
509 	switch (errno) {
510 	case -EIO:
511 		errstr = "IO failure";
512 		break;
513 	case -ENOMEM:
514 		errstr = "Out of memory";
515 		break;
516 	case -EROFS:
517 		if (!sb || (EXT4_SB(sb)->s_journal &&
518 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
519 			errstr = "Journal has aborted";
520 		else
521 			errstr = "Readonly filesystem";
522 		break;
523 	default:
524 		/* If the caller passed in an extra buffer for unknown
525 		 * errors, textualise them now.  Else we just return
526 		 * NULL. */
527 		if (nbuf) {
528 			/* Check for truncated error codes... */
529 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
530 				errstr = nbuf;
531 		}
532 		break;
533 	}
534 
535 	return errstr;
536 }
537 
538 /* __ext4_std_error decodes expected errors from journaling functions
539  * automatically and invokes the appropriate error response.  */
540 
541 void __ext4_std_error(struct super_block *sb, const char *function,
542 		      unsigned int line, int errno)
543 {
544 	char nbuf[16];
545 	const char *errstr;
546 
547 	/* Special case: if the error is EROFS, and we're not already
548 	 * inside a transaction, then there's really no point in logging
549 	 * an error. */
550 	if (errno == -EROFS && journal_current_handle() == NULL &&
551 	    (sb->s_flags & MS_RDONLY))
552 		return;
553 
554 	if (ext4_error_ratelimit(sb)) {
555 		errstr = ext4_decode_error(sb, errno, nbuf);
556 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
557 		       sb->s_id, function, line, errstr);
558 	}
559 
560 	save_error_info(sb, function, line);
561 	ext4_handle_error(sb);
562 }
563 
564 /*
565  * ext4_abort is a much stronger failure handler than ext4_error.  The
566  * abort function may be used to deal with unrecoverable failures such
567  * as journal IO errors or ENOMEM at a critical moment in log management.
568  *
569  * We unconditionally force the filesystem into an ABORT|READONLY state,
570  * unless the error response on the fs has been set to panic in which
571  * case we take the easy way out and panic immediately.
572  */
573 
574 void __ext4_abort(struct super_block *sb, const char *function,
575 		unsigned int line, const char *fmt, ...)
576 {
577 	va_list args;
578 
579 	save_error_info(sb, function, line);
580 	va_start(args, fmt);
581 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
582 	       function, line);
583 	vprintk(fmt, args);
584 	printk("\n");
585 	va_end(args);
586 
587 	if ((sb->s_flags & MS_RDONLY) == 0) {
588 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
589 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
590 		/*
591 		 * Make sure updated value of ->s_mount_flags will be visible
592 		 * before ->s_flags update
593 		 */
594 		smp_wmb();
595 		sb->s_flags |= MS_RDONLY;
596 		if (EXT4_SB(sb)->s_journal)
597 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
598 		save_error_info(sb, function, line);
599 	}
600 	if (test_opt(sb, ERRORS_PANIC))
601 		panic("EXT4-fs panic from previous error\n");
602 }
603 
604 void __ext4_msg(struct super_block *sb,
605 		const char *prefix, const char *fmt, ...)
606 {
607 	struct va_format vaf;
608 	va_list args;
609 
610 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
611 		return;
612 
613 	va_start(args, fmt);
614 	vaf.fmt = fmt;
615 	vaf.va = &args;
616 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
617 	va_end(args);
618 }
619 
620 void __ext4_warning(struct super_block *sb, const char *function,
621 		    unsigned int line, const char *fmt, ...)
622 {
623 	struct va_format vaf;
624 	va_list args;
625 
626 	if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
627 			  "EXT4-fs warning"))
628 		return;
629 
630 	va_start(args, fmt);
631 	vaf.fmt = fmt;
632 	vaf.va = &args;
633 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
634 	       sb->s_id, function, line, &vaf);
635 	va_end(args);
636 }
637 
638 void __ext4_grp_locked_error(const char *function, unsigned int line,
639 			     struct super_block *sb, ext4_group_t grp,
640 			     unsigned long ino, ext4_fsblk_t block,
641 			     const char *fmt, ...)
642 __releases(bitlock)
643 __acquires(bitlock)
644 {
645 	struct va_format vaf;
646 	va_list args;
647 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
648 
649 	es->s_last_error_ino = cpu_to_le32(ino);
650 	es->s_last_error_block = cpu_to_le64(block);
651 	__save_error_info(sb, function, line);
652 
653 	if (ext4_error_ratelimit(sb)) {
654 		va_start(args, fmt);
655 		vaf.fmt = fmt;
656 		vaf.va = &args;
657 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
658 		       sb->s_id, function, line, grp);
659 		if (ino)
660 			printk(KERN_CONT "inode %lu: ", ino);
661 		if (block)
662 			printk(KERN_CONT "block %llu:",
663 			       (unsigned long long) block);
664 		printk(KERN_CONT "%pV\n", &vaf);
665 		va_end(args);
666 	}
667 
668 	if (test_opt(sb, ERRORS_CONT)) {
669 		ext4_commit_super(sb, 0);
670 		return;
671 	}
672 
673 	ext4_unlock_group(sb, grp);
674 	ext4_handle_error(sb);
675 	/*
676 	 * We only get here in the ERRORS_RO case; relocking the group
677 	 * may be dangerous, but nothing bad will happen since the
678 	 * filesystem will have already been marked read/only and the
679 	 * journal has been aborted.  We return 1 as a hint to callers
680 	 * who might what to use the return value from
681 	 * ext4_grp_locked_error() to distinguish between the
682 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
683 	 * aggressively from the ext4 function in question, with a
684 	 * more appropriate error code.
685 	 */
686 	ext4_lock_group(sb, grp);
687 	return;
688 }
689 
690 void ext4_update_dynamic_rev(struct super_block *sb)
691 {
692 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
693 
694 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
695 		return;
696 
697 	ext4_warning(sb,
698 		     "updating to rev %d because of new feature flag, "
699 		     "running e2fsck is recommended",
700 		     EXT4_DYNAMIC_REV);
701 
702 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
703 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
704 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
705 	/* leave es->s_feature_*compat flags alone */
706 	/* es->s_uuid will be set by e2fsck if empty */
707 
708 	/*
709 	 * The rest of the superblock fields should be zero, and if not it
710 	 * means they are likely already in use, so leave them alone.  We
711 	 * can leave it up to e2fsck to clean up any inconsistencies there.
712 	 */
713 }
714 
715 /*
716  * Open the external journal device
717  */
718 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
719 {
720 	struct block_device *bdev;
721 	char b[BDEVNAME_SIZE];
722 
723 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
724 	if (IS_ERR(bdev))
725 		goto fail;
726 	return bdev;
727 
728 fail:
729 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
730 			__bdevname(dev, b), PTR_ERR(bdev));
731 	return NULL;
732 }
733 
734 /*
735  * Release the journal device
736  */
737 static void ext4_blkdev_put(struct block_device *bdev)
738 {
739 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
740 }
741 
742 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
743 {
744 	struct block_device *bdev;
745 	bdev = sbi->journal_bdev;
746 	if (bdev) {
747 		ext4_blkdev_put(bdev);
748 		sbi->journal_bdev = NULL;
749 	}
750 }
751 
752 static inline struct inode *orphan_list_entry(struct list_head *l)
753 {
754 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
755 }
756 
757 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
758 {
759 	struct list_head *l;
760 
761 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
762 		 le32_to_cpu(sbi->s_es->s_last_orphan));
763 
764 	printk(KERN_ERR "sb_info orphan list:\n");
765 	list_for_each(l, &sbi->s_orphan) {
766 		struct inode *inode = orphan_list_entry(l);
767 		printk(KERN_ERR "  "
768 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
769 		       inode->i_sb->s_id, inode->i_ino, inode,
770 		       inode->i_mode, inode->i_nlink,
771 		       NEXT_ORPHAN(inode));
772 	}
773 }
774 
775 static void ext4_put_super(struct super_block *sb)
776 {
777 	struct ext4_sb_info *sbi = EXT4_SB(sb);
778 	struct ext4_super_block *es = sbi->s_es;
779 	int i, err;
780 
781 	ext4_unregister_li_request(sb);
782 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
783 
784 	flush_workqueue(sbi->rsv_conversion_wq);
785 	destroy_workqueue(sbi->rsv_conversion_wq);
786 
787 	if (sbi->s_journal) {
788 		err = jbd2_journal_destroy(sbi->s_journal);
789 		sbi->s_journal = NULL;
790 		if (err < 0)
791 			ext4_abort(sb, "Couldn't clean up the journal");
792 	}
793 
794 	ext4_es_unregister_shrinker(sbi);
795 	del_timer(&sbi->s_err_report);
796 	ext4_release_system_zone(sb);
797 	ext4_mb_release(sb);
798 	ext4_ext_release(sb);
799 	ext4_xattr_put_super(sb);
800 
801 	if (!(sb->s_flags & MS_RDONLY)) {
802 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
803 		es->s_state = cpu_to_le16(sbi->s_mount_state);
804 	}
805 	if (!(sb->s_flags & MS_RDONLY))
806 		ext4_commit_super(sb, 1);
807 
808 	if (sbi->s_proc) {
809 		remove_proc_entry("options", sbi->s_proc);
810 		remove_proc_entry(sb->s_id, ext4_proc_root);
811 	}
812 	kobject_del(&sbi->s_kobj);
813 
814 	for (i = 0; i < sbi->s_gdb_count; i++)
815 		brelse(sbi->s_group_desc[i]);
816 	ext4_kvfree(sbi->s_group_desc);
817 	ext4_kvfree(sbi->s_flex_groups);
818 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
819 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
820 	percpu_counter_destroy(&sbi->s_dirs_counter);
821 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
822 	percpu_counter_destroy(&sbi->s_extent_cache_cnt);
823 	brelse(sbi->s_sbh);
824 #ifdef CONFIG_QUOTA
825 	for (i = 0; i < MAXQUOTAS; i++)
826 		kfree(sbi->s_qf_names[i]);
827 #endif
828 
829 	/* Debugging code just in case the in-memory inode orphan list
830 	 * isn't empty.  The on-disk one can be non-empty if we've
831 	 * detected an error and taken the fs readonly, but the
832 	 * in-memory list had better be clean by this point. */
833 	if (!list_empty(&sbi->s_orphan))
834 		dump_orphan_list(sb, sbi);
835 	J_ASSERT(list_empty(&sbi->s_orphan));
836 
837 	invalidate_bdev(sb->s_bdev);
838 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
839 		/*
840 		 * Invalidate the journal device's buffers.  We don't want them
841 		 * floating about in memory - the physical journal device may
842 		 * hotswapped, and it breaks the `ro-after' testing code.
843 		 */
844 		sync_blockdev(sbi->journal_bdev);
845 		invalidate_bdev(sbi->journal_bdev);
846 		ext4_blkdev_remove(sbi);
847 	}
848 	if (sbi->s_mmp_tsk)
849 		kthread_stop(sbi->s_mmp_tsk);
850 	sb->s_fs_info = NULL;
851 	/*
852 	 * Now that we are completely done shutting down the
853 	 * superblock, we need to actually destroy the kobject.
854 	 */
855 	kobject_put(&sbi->s_kobj);
856 	wait_for_completion(&sbi->s_kobj_unregister);
857 	if (sbi->s_chksum_driver)
858 		crypto_free_shash(sbi->s_chksum_driver);
859 	kfree(sbi->s_blockgroup_lock);
860 	kfree(sbi);
861 }
862 
863 static struct kmem_cache *ext4_inode_cachep;
864 
865 /*
866  * Called inside transaction, so use GFP_NOFS
867  */
868 static struct inode *ext4_alloc_inode(struct super_block *sb)
869 {
870 	struct ext4_inode_info *ei;
871 
872 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
873 	if (!ei)
874 		return NULL;
875 
876 	ei->vfs_inode.i_version = 1;
877 	INIT_LIST_HEAD(&ei->i_prealloc_list);
878 	spin_lock_init(&ei->i_prealloc_lock);
879 	ext4_es_init_tree(&ei->i_es_tree);
880 	rwlock_init(&ei->i_es_lock);
881 	INIT_LIST_HEAD(&ei->i_es_lru);
882 	ei->i_es_lru_nr = 0;
883 	ei->i_touch_when = 0;
884 	ei->i_reserved_data_blocks = 0;
885 	ei->i_reserved_meta_blocks = 0;
886 	ei->i_allocated_meta_blocks = 0;
887 	ei->i_da_metadata_calc_len = 0;
888 	ei->i_da_metadata_calc_last_lblock = 0;
889 	spin_lock_init(&(ei->i_block_reservation_lock));
890 #ifdef CONFIG_QUOTA
891 	ei->i_reserved_quota = 0;
892 #endif
893 	ei->jinode = NULL;
894 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
895 	spin_lock_init(&ei->i_completed_io_lock);
896 	ei->i_sync_tid = 0;
897 	ei->i_datasync_tid = 0;
898 	atomic_set(&ei->i_ioend_count, 0);
899 	atomic_set(&ei->i_unwritten, 0);
900 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
901 
902 	return &ei->vfs_inode;
903 }
904 
905 static int ext4_drop_inode(struct inode *inode)
906 {
907 	int drop = generic_drop_inode(inode);
908 
909 	trace_ext4_drop_inode(inode, drop);
910 	return drop;
911 }
912 
913 static void ext4_i_callback(struct rcu_head *head)
914 {
915 	struct inode *inode = container_of(head, struct inode, i_rcu);
916 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
917 }
918 
919 static void ext4_destroy_inode(struct inode *inode)
920 {
921 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
922 		ext4_msg(inode->i_sb, KERN_ERR,
923 			 "Inode %lu (%p): orphan list check failed!",
924 			 inode->i_ino, EXT4_I(inode));
925 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
926 				EXT4_I(inode), sizeof(struct ext4_inode_info),
927 				true);
928 		dump_stack();
929 	}
930 	call_rcu(&inode->i_rcu, ext4_i_callback);
931 }
932 
933 static void init_once(void *foo)
934 {
935 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
936 
937 	INIT_LIST_HEAD(&ei->i_orphan);
938 	init_rwsem(&ei->xattr_sem);
939 	init_rwsem(&ei->i_data_sem);
940 	inode_init_once(&ei->vfs_inode);
941 }
942 
943 static int init_inodecache(void)
944 {
945 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
946 					     sizeof(struct ext4_inode_info),
947 					     0, (SLAB_RECLAIM_ACCOUNT|
948 						SLAB_MEM_SPREAD),
949 					     init_once);
950 	if (ext4_inode_cachep == NULL)
951 		return -ENOMEM;
952 	return 0;
953 }
954 
955 static void destroy_inodecache(void)
956 {
957 	/*
958 	 * Make sure all delayed rcu free inodes are flushed before we
959 	 * destroy cache.
960 	 */
961 	rcu_barrier();
962 	kmem_cache_destroy(ext4_inode_cachep);
963 }
964 
965 void ext4_clear_inode(struct inode *inode)
966 {
967 	invalidate_inode_buffers(inode);
968 	clear_inode(inode);
969 	dquot_drop(inode);
970 	ext4_discard_preallocations(inode);
971 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
972 	ext4_es_lru_del(inode);
973 	if (EXT4_I(inode)->jinode) {
974 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
975 					       EXT4_I(inode)->jinode);
976 		jbd2_free_inode(EXT4_I(inode)->jinode);
977 		EXT4_I(inode)->jinode = NULL;
978 	}
979 }
980 
981 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
982 					u64 ino, u32 generation)
983 {
984 	struct inode *inode;
985 
986 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
987 		return ERR_PTR(-ESTALE);
988 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
989 		return ERR_PTR(-ESTALE);
990 
991 	/* iget isn't really right if the inode is currently unallocated!!
992 	 *
993 	 * ext4_read_inode will return a bad_inode if the inode had been
994 	 * deleted, so we should be safe.
995 	 *
996 	 * Currently we don't know the generation for parent directory, so
997 	 * a generation of 0 means "accept any"
998 	 */
999 	inode = ext4_iget(sb, ino);
1000 	if (IS_ERR(inode))
1001 		return ERR_CAST(inode);
1002 	if (generation && inode->i_generation != generation) {
1003 		iput(inode);
1004 		return ERR_PTR(-ESTALE);
1005 	}
1006 
1007 	return inode;
1008 }
1009 
1010 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1011 					int fh_len, int fh_type)
1012 {
1013 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1014 				    ext4_nfs_get_inode);
1015 }
1016 
1017 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1018 					int fh_len, int fh_type)
1019 {
1020 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1021 				    ext4_nfs_get_inode);
1022 }
1023 
1024 /*
1025  * Try to release metadata pages (indirect blocks, directories) which are
1026  * mapped via the block device.  Since these pages could have journal heads
1027  * which would prevent try_to_free_buffers() from freeing them, we must use
1028  * jbd2 layer's try_to_free_buffers() function to release them.
1029  */
1030 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1031 				 gfp_t wait)
1032 {
1033 	journal_t *journal = EXT4_SB(sb)->s_journal;
1034 
1035 	WARN_ON(PageChecked(page));
1036 	if (!page_has_buffers(page))
1037 		return 0;
1038 	if (journal)
1039 		return jbd2_journal_try_to_free_buffers(journal, page,
1040 							wait & ~__GFP_WAIT);
1041 	return try_to_free_buffers(page);
1042 }
1043 
1044 #ifdef CONFIG_QUOTA
1045 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1046 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1047 
1048 static int ext4_write_dquot(struct dquot *dquot);
1049 static int ext4_acquire_dquot(struct dquot *dquot);
1050 static int ext4_release_dquot(struct dquot *dquot);
1051 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1052 static int ext4_write_info(struct super_block *sb, int type);
1053 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1054 			 struct path *path);
1055 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1056 				 int format_id);
1057 static int ext4_quota_off(struct super_block *sb, int type);
1058 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1059 static int ext4_quota_on_mount(struct super_block *sb, int type);
1060 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1061 			       size_t len, loff_t off);
1062 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1063 				const char *data, size_t len, loff_t off);
1064 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1065 			     unsigned int flags);
1066 static int ext4_enable_quotas(struct super_block *sb);
1067 
1068 static const struct dquot_operations ext4_quota_operations = {
1069 	.get_reserved_space = ext4_get_reserved_space,
1070 	.write_dquot	= ext4_write_dquot,
1071 	.acquire_dquot	= ext4_acquire_dquot,
1072 	.release_dquot	= ext4_release_dquot,
1073 	.mark_dirty	= ext4_mark_dquot_dirty,
1074 	.write_info	= ext4_write_info,
1075 	.alloc_dquot	= dquot_alloc,
1076 	.destroy_dquot	= dquot_destroy,
1077 };
1078 
1079 static const struct quotactl_ops ext4_qctl_operations = {
1080 	.quota_on	= ext4_quota_on,
1081 	.quota_off	= ext4_quota_off,
1082 	.quota_sync	= dquot_quota_sync,
1083 	.get_info	= dquot_get_dqinfo,
1084 	.set_info	= dquot_set_dqinfo,
1085 	.get_dqblk	= dquot_get_dqblk,
1086 	.set_dqblk	= dquot_set_dqblk
1087 };
1088 
1089 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1090 	.quota_on_meta	= ext4_quota_on_sysfile,
1091 	.quota_off	= ext4_quota_off_sysfile,
1092 	.quota_sync	= dquot_quota_sync,
1093 	.get_info	= dquot_get_dqinfo,
1094 	.set_info	= dquot_set_dqinfo,
1095 	.get_dqblk	= dquot_get_dqblk,
1096 	.set_dqblk	= dquot_set_dqblk
1097 };
1098 #endif
1099 
1100 static const struct super_operations ext4_sops = {
1101 	.alloc_inode	= ext4_alloc_inode,
1102 	.destroy_inode	= ext4_destroy_inode,
1103 	.write_inode	= ext4_write_inode,
1104 	.dirty_inode	= ext4_dirty_inode,
1105 	.drop_inode	= ext4_drop_inode,
1106 	.evict_inode	= ext4_evict_inode,
1107 	.put_super	= ext4_put_super,
1108 	.sync_fs	= ext4_sync_fs,
1109 	.freeze_fs	= ext4_freeze,
1110 	.unfreeze_fs	= ext4_unfreeze,
1111 	.statfs		= ext4_statfs,
1112 	.remount_fs	= ext4_remount,
1113 	.show_options	= ext4_show_options,
1114 #ifdef CONFIG_QUOTA
1115 	.quota_read	= ext4_quota_read,
1116 	.quota_write	= ext4_quota_write,
1117 #endif
1118 	.bdev_try_to_free_page = bdev_try_to_free_page,
1119 };
1120 
1121 static const struct super_operations ext4_nojournal_sops = {
1122 	.alloc_inode	= ext4_alloc_inode,
1123 	.destroy_inode	= ext4_destroy_inode,
1124 	.write_inode	= ext4_write_inode,
1125 	.dirty_inode	= ext4_dirty_inode,
1126 	.drop_inode	= ext4_drop_inode,
1127 	.evict_inode	= ext4_evict_inode,
1128 	.sync_fs	= ext4_sync_fs_nojournal,
1129 	.put_super	= ext4_put_super,
1130 	.statfs		= ext4_statfs,
1131 	.remount_fs	= ext4_remount,
1132 	.show_options	= ext4_show_options,
1133 #ifdef CONFIG_QUOTA
1134 	.quota_read	= ext4_quota_read,
1135 	.quota_write	= ext4_quota_write,
1136 #endif
1137 	.bdev_try_to_free_page = bdev_try_to_free_page,
1138 };
1139 
1140 static const struct export_operations ext4_export_ops = {
1141 	.fh_to_dentry = ext4_fh_to_dentry,
1142 	.fh_to_parent = ext4_fh_to_parent,
1143 	.get_parent = ext4_get_parent,
1144 };
1145 
1146 enum {
1147 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1148 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1149 	Opt_nouid32, Opt_debug, Opt_removed,
1150 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1151 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1152 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1153 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1154 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1155 	Opt_data_err_abort, Opt_data_err_ignore,
1156 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1157 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1158 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1159 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1160 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1161 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1162 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1163 	Opt_dioread_nolock, Opt_dioread_lock,
1164 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1165 	Opt_max_dir_size_kb,
1166 };
1167 
1168 static const match_table_t tokens = {
1169 	{Opt_bsd_df, "bsddf"},
1170 	{Opt_minix_df, "minixdf"},
1171 	{Opt_grpid, "grpid"},
1172 	{Opt_grpid, "bsdgroups"},
1173 	{Opt_nogrpid, "nogrpid"},
1174 	{Opt_nogrpid, "sysvgroups"},
1175 	{Opt_resgid, "resgid=%u"},
1176 	{Opt_resuid, "resuid=%u"},
1177 	{Opt_sb, "sb=%u"},
1178 	{Opt_err_cont, "errors=continue"},
1179 	{Opt_err_panic, "errors=panic"},
1180 	{Opt_err_ro, "errors=remount-ro"},
1181 	{Opt_nouid32, "nouid32"},
1182 	{Opt_debug, "debug"},
1183 	{Opt_removed, "oldalloc"},
1184 	{Opt_removed, "orlov"},
1185 	{Opt_user_xattr, "user_xattr"},
1186 	{Opt_nouser_xattr, "nouser_xattr"},
1187 	{Opt_acl, "acl"},
1188 	{Opt_noacl, "noacl"},
1189 	{Opt_noload, "norecovery"},
1190 	{Opt_noload, "noload"},
1191 	{Opt_removed, "nobh"},
1192 	{Opt_removed, "bh"},
1193 	{Opt_commit, "commit=%u"},
1194 	{Opt_min_batch_time, "min_batch_time=%u"},
1195 	{Opt_max_batch_time, "max_batch_time=%u"},
1196 	{Opt_journal_dev, "journal_dev=%u"},
1197 	{Opt_journal_path, "journal_path=%s"},
1198 	{Opt_journal_checksum, "journal_checksum"},
1199 	{Opt_journal_async_commit, "journal_async_commit"},
1200 	{Opt_abort, "abort"},
1201 	{Opt_data_journal, "data=journal"},
1202 	{Opt_data_ordered, "data=ordered"},
1203 	{Opt_data_writeback, "data=writeback"},
1204 	{Opt_data_err_abort, "data_err=abort"},
1205 	{Opt_data_err_ignore, "data_err=ignore"},
1206 	{Opt_offusrjquota, "usrjquota="},
1207 	{Opt_usrjquota, "usrjquota=%s"},
1208 	{Opt_offgrpjquota, "grpjquota="},
1209 	{Opt_grpjquota, "grpjquota=%s"},
1210 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1211 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1212 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1213 	{Opt_grpquota, "grpquota"},
1214 	{Opt_noquota, "noquota"},
1215 	{Opt_quota, "quota"},
1216 	{Opt_usrquota, "usrquota"},
1217 	{Opt_barrier, "barrier=%u"},
1218 	{Opt_barrier, "barrier"},
1219 	{Opt_nobarrier, "nobarrier"},
1220 	{Opt_i_version, "i_version"},
1221 	{Opt_stripe, "stripe=%u"},
1222 	{Opt_delalloc, "delalloc"},
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_removed, "check=none"},	/* mount option from ext2/3 */
1242 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1243 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1244 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1245 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1246 	{Opt_err, NULL},
1247 };
1248 
1249 static ext4_fsblk_t get_sb_block(void **data)
1250 {
1251 	ext4_fsblk_t	sb_block;
1252 	char		*options = (char *) *data;
1253 
1254 	if (!options || strncmp(options, "sb=", 3) != 0)
1255 		return 1;	/* Default location */
1256 
1257 	options += 3;
1258 	/* TODO: use simple_strtoll with >32bit ext4 */
1259 	sb_block = simple_strtoul(options, &options, 0);
1260 	if (*options && *options != ',') {
1261 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1262 		       (char *) *data);
1263 		return 1;
1264 	}
1265 	if (*options == ',')
1266 		options++;
1267 	*data = (void *) options;
1268 
1269 	return sb_block;
1270 }
1271 
1272 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1273 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1274 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1275 
1276 #ifdef CONFIG_QUOTA
1277 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1278 {
1279 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1280 	char *qname;
1281 	int ret = -1;
1282 
1283 	if (sb_any_quota_loaded(sb) &&
1284 		!sbi->s_qf_names[qtype]) {
1285 		ext4_msg(sb, KERN_ERR,
1286 			"Cannot change journaled "
1287 			"quota options when quota turned on");
1288 		return -1;
1289 	}
1290 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1291 		ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1292 			 "when QUOTA feature is enabled");
1293 		return -1;
1294 	}
1295 	qname = match_strdup(args);
1296 	if (!qname) {
1297 		ext4_msg(sb, KERN_ERR,
1298 			"Not enough memory for storing quotafile name");
1299 		return -1;
1300 	}
1301 	if (sbi->s_qf_names[qtype]) {
1302 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1303 			ret = 1;
1304 		else
1305 			ext4_msg(sb, KERN_ERR,
1306 				 "%s quota file already specified",
1307 				 QTYPE2NAME(qtype));
1308 		goto errout;
1309 	}
1310 	if (strchr(qname, '/')) {
1311 		ext4_msg(sb, KERN_ERR,
1312 			"quotafile must be on filesystem root");
1313 		goto errout;
1314 	}
1315 	sbi->s_qf_names[qtype] = qname;
1316 	set_opt(sb, QUOTA);
1317 	return 1;
1318 errout:
1319 	kfree(qname);
1320 	return ret;
1321 }
1322 
1323 static int clear_qf_name(struct super_block *sb, int qtype)
1324 {
1325 
1326 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1327 
1328 	if (sb_any_quota_loaded(sb) &&
1329 		sbi->s_qf_names[qtype]) {
1330 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1331 			" when quota turned on");
1332 		return -1;
1333 	}
1334 	kfree(sbi->s_qf_names[qtype]);
1335 	sbi->s_qf_names[qtype] = NULL;
1336 	return 1;
1337 }
1338 #endif
1339 
1340 #define MOPT_SET	0x0001
1341 #define MOPT_CLEAR	0x0002
1342 #define MOPT_NOSUPPORT	0x0004
1343 #define MOPT_EXPLICIT	0x0008
1344 #define MOPT_CLEAR_ERR	0x0010
1345 #define MOPT_GTE0	0x0020
1346 #ifdef CONFIG_QUOTA
1347 #define MOPT_Q		0
1348 #define MOPT_QFMT	0x0040
1349 #else
1350 #define MOPT_Q		MOPT_NOSUPPORT
1351 #define MOPT_QFMT	MOPT_NOSUPPORT
1352 #endif
1353 #define MOPT_DATAJ	0x0080
1354 #define MOPT_NO_EXT2	0x0100
1355 #define MOPT_NO_EXT3	0x0200
1356 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1357 #define MOPT_STRING	0x0400
1358 
1359 static const struct mount_opts {
1360 	int	token;
1361 	int	mount_opt;
1362 	int	flags;
1363 } ext4_mount_opts[] = {
1364 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1365 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1366 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1367 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1368 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1369 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1370 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1371 	 MOPT_EXT4_ONLY | MOPT_SET},
1372 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1373 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1374 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1375 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1376 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1377 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1378 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1379 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1380 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1381 	 MOPT_EXT4_ONLY | MOPT_SET},
1382 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1383 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1384 	 MOPT_EXT4_ONLY | MOPT_SET},
1385 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1386 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1387 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1388 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1389 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1390 	 MOPT_NO_EXT2 | MOPT_SET},
1391 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1392 	 MOPT_NO_EXT2 | MOPT_CLEAR},
1393 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1394 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1395 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1396 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1397 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1398 	{Opt_commit, 0, MOPT_GTE0},
1399 	{Opt_max_batch_time, 0, MOPT_GTE0},
1400 	{Opt_min_batch_time, 0, MOPT_GTE0},
1401 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1402 	{Opt_init_itable, 0, MOPT_GTE0},
1403 	{Opt_stripe, 0, MOPT_GTE0},
1404 	{Opt_resuid, 0, MOPT_GTE0},
1405 	{Opt_resgid, 0, MOPT_GTE0},
1406 	{Opt_journal_dev, 0, MOPT_GTE0},
1407 	{Opt_journal_path, 0, MOPT_STRING},
1408 	{Opt_journal_ioprio, 0, MOPT_GTE0},
1409 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1410 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1411 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1412 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1413 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1414 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1415 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1416 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1417 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1418 #else
1419 	{Opt_acl, 0, MOPT_NOSUPPORT},
1420 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1421 #endif
1422 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1423 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1424 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1425 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1426 							MOPT_SET | MOPT_Q},
1427 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1428 							MOPT_SET | MOPT_Q},
1429 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1430 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1431 	{Opt_usrjquota, 0, MOPT_Q},
1432 	{Opt_grpjquota, 0, MOPT_Q},
1433 	{Opt_offusrjquota, 0, MOPT_Q},
1434 	{Opt_offgrpjquota, 0, MOPT_Q},
1435 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1436 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1437 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1438 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1439 	{Opt_err, 0, 0}
1440 };
1441 
1442 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1443 			    substring_t *args, unsigned long *journal_devnum,
1444 			    unsigned int *journal_ioprio, int is_remount)
1445 {
1446 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1447 	const struct mount_opts *m;
1448 	kuid_t uid;
1449 	kgid_t gid;
1450 	int arg = 0;
1451 
1452 #ifdef CONFIG_QUOTA
1453 	if (token == Opt_usrjquota)
1454 		return set_qf_name(sb, USRQUOTA, &args[0]);
1455 	else if (token == Opt_grpjquota)
1456 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1457 	else if (token == Opt_offusrjquota)
1458 		return clear_qf_name(sb, USRQUOTA);
1459 	else if (token == Opt_offgrpjquota)
1460 		return clear_qf_name(sb, GRPQUOTA);
1461 #endif
1462 	switch (token) {
1463 	case Opt_noacl:
1464 	case Opt_nouser_xattr:
1465 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1466 		break;
1467 	case Opt_sb:
1468 		return 1;	/* handled by get_sb_block() */
1469 	case Opt_removed:
1470 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1471 		return 1;
1472 	case Opt_abort:
1473 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1474 		return 1;
1475 	case Opt_i_version:
1476 		sb->s_flags |= MS_I_VERSION;
1477 		return 1;
1478 	}
1479 
1480 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1481 		if (token == m->token)
1482 			break;
1483 
1484 	if (m->token == Opt_err) {
1485 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1486 			 "or missing value", opt);
1487 		return -1;
1488 	}
1489 
1490 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1491 		ext4_msg(sb, KERN_ERR,
1492 			 "Mount option \"%s\" incompatible with ext2", opt);
1493 		return -1;
1494 	}
1495 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1496 		ext4_msg(sb, KERN_ERR,
1497 			 "Mount option \"%s\" incompatible with ext3", opt);
1498 		return -1;
1499 	}
1500 
1501 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1502 		return -1;
1503 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1504 		return -1;
1505 	if (m->flags & MOPT_EXPLICIT)
1506 		set_opt2(sb, EXPLICIT_DELALLOC);
1507 	if (m->flags & MOPT_CLEAR_ERR)
1508 		clear_opt(sb, ERRORS_MASK);
1509 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1510 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1511 			 "options when quota turned on");
1512 		return -1;
1513 	}
1514 
1515 	if (m->flags & MOPT_NOSUPPORT) {
1516 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1517 	} else if (token == Opt_commit) {
1518 		if (arg == 0)
1519 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1520 		sbi->s_commit_interval = HZ * arg;
1521 	} else if (token == Opt_max_batch_time) {
1522 		if (arg == 0)
1523 			arg = EXT4_DEF_MAX_BATCH_TIME;
1524 		sbi->s_max_batch_time = arg;
1525 	} else if (token == Opt_min_batch_time) {
1526 		sbi->s_min_batch_time = arg;
1527 	} else if (token == Opt_inode_readahead_blks) {
1528 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1529 			ext4_msg(sb, KERN_ERR,
1530 				 "EXT4-fs: inode_readahead_blks must be "
1531 				 "0 or a power of 2 smaller than 2^31");
1532 			return -1;
1533 		}
1534 		sbi->s_inode_readahead_blks = arg;
1535 	} else if (token == Opt_init_itable) {
1536 		set_opt(sb, INIT_INODE_TABLE);
1537 		if (!args->from)
1538 			arg = EXT4_DEF_LI_WAIT_MULT;
1539 		sbi->s_li_wait_mult = arg;
1540 	} else if (token == Opt_max_dir_size_kb) {
1541 		sbi->s_max_dir_size_kb = arg;
1542 	} else if (token == Opt_stripe) {
1543 		sbi->s_stripe = arg;
1544 	} else if (token == Opt_resuid) {
1545 		uid = make_kuid(current_user_ns(), arg);
1546 		if (!uid_valid(uid)) {
1547 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1548 			return -1;
1549 		}
1550 		sbi->s_resuid = uid;
1551 	} else if (token == Opt_resgid) {
1552 		gid = make_kgid(current_user_ns(), arg);
1553 		if (!gid_valid(gid)) {
1554 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1555 			return -1;
1556 		}
1557 		sbi->s_resgid = gid;
1558 	} else if (token == Opt_journal_dev) {
1559 		if (is_remount) {
1560 			ext4_msg(sb, KERN_ERR,
1561 				 "Cannot specify journal on remount");
1562 			return -1;
1563 		}
1564 		*journal_devnum = arg;
1565 	} else if (token == Opt_journal_path) {
1566 		char *journal_path;
1567 		struct inode *journal_inode;
1568 		struct path path;
1569 		int error;
1570 
1571 		if (is_remount) {
1572 			ext4_msg(sb, KERN_ERR,
1573 				 "Cannot specify journal on remount");
1574 			return -1;
1575 		}
1576 		journal_path = match_strdup(&args[0]);
1577 		if (!journal_path) {
1578 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1579 				"journal device string");
1580 			return -1;
1581 		}
1582 
1583 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1584 		if (error) {
1585 			ext4_msg(sb, KERN_ERR, "error: could not find "
1586 				"journal device path: error %d", error);
1587 			kfree(journal_path);
1588 			return -1;
1589 		}
1590 
1591 		journal_inode = path.dentry->d_inode;
1592 		if (!S_ISBLK(journal_inode->i_mode)) {
1593 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1594 				"is not a block device", journal_path);
1595 			path_put(&path);
1596 			kfree(journal_path);
1597 			return -1;
1598 		}
1599 
1600 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1601 		path_put(&path);
1602 		kfree(journal_path);
1603 	} else if (token == Opt_journal_ioprio) {
1604 		if (arg > 7) {
1605 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1606 				 " (must be 0-7)");
1607 			return -1;
1608 		}
1609 		*journal_ioprio =
1610 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1611 	} else if (m->flags & MOPT_DATAJ) {
1612 		if (is_remount) {
1613 			if (!sbi->s_journal)
1614 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1615 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1616 				ext4_msg(sb, KERN_ERR,
1617 					 "Cannot change data mode on remount");
1618 				return -1;
1619 			}
1620 		} else {
1621 			clear_opt(sb, DATA_FLAGS);
1622 			sbi->s_mount_opt |= m->mount_opt;
1623 		}
1624 #ifdef CONFIG_QUOTA
1625 	} else if (m->flags & MOPT_QFMT) {
1626 		if (sb_any_quota_loaded(sb) &&
1627 		    sbi->s_jquota_fmt != m->mount_opt) {
1628 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1629 				 "quota options when quota turned on");
1630 			return -1;
1631 		}
1632 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1633 					       EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1634 			ext4_msg(sb, KERN_ERR,
1635 				 "Cannot set journaled quota options "
1636 				 "when QUOTA feature is enabled");
1637 			return -1;
1638 		}
1639 		sbi->s_jquota_fmt = m->mount_opt;
1640 #endif
1641 	} else {
1642 		if (!args->from)
1643 			arg = 1;
1644 		if (m->flags & MOPT_CLEAR)
1645 			arg = !arg;
1646 		else if (unlikely(!(m->flags & MOPT_SET))) {
1647 			ext4_msg(sb, KERN_WARNING,
1648 				 "buggy handling of option %s", opt);
1649 			WARN_ON(1);
1650 			return -1;
1651 		}
1652 		if (arg != 0)
1653 			sbi->s_mount_opt |= m->mount_opt;
1654 		else
1655 			sbi->s_mount_opt &= ~m->mount_opt;
1656 	}
1657 	return 1;
1658 }
1659 
1660 static int parse_options(char *options, struct super_block *sb,
1661 			 unsigned long *journal_devnum,
1662 			 unsigned int *journal_ioprio,
1663 			 int is_remount)
1664 {
1665 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1666 	char *p;
1667 	substring_t args[MAX_OPT_ARGS];
1668 	int token;
1669 
1670 	if (!options)
1671 		return 1;
1672 
1673 	while ((p = strsep(&options, ",")) != NULL) {
1674 		if (!*p)
1675 			continue;
1676 		/*
1677 		 * Initialize args struct so we know whether arg was
1678 		 * found; some options take optional arguments.
1679 		 */
1680 		args[0].to = args[0].from = NULL;
1681 		token = match_token(p, tokens, args);
1682 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1683 				     journal_ioprio, is_remount) < 0)
1684 			return 0;
1685 	}
1686 #ifdef CONFIG_QUOTA
1687 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1688 	    (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1689 		ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1690 			 "feature is enabled");
1691 		return 0;
1692 	}
1693 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1694 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1695 			clear_opt(sb, USRQUOTA);
1696 
1697 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1698 			clear_opt(sb, GRPQUOTA);
1699 
1700 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1701 			ext4_msg(sb, KERN_ERR, "old and new quota "
1702 					"format mixing");
1703 			return 0;
1704 		}
1705 
1706 		if (!sbi->s_jquota_fmt) {
1707 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1708 					"not specified");
1709 			return 0;
1710 		}
1711 	} else {
1712 		if (sbi->s_jquota_fmt) {
1713 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1714 					"specified with no journaling "
1715 					"enabled");
1716 			return 0;
1717 		}
1718 	}
1719 #endif
1720 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1721 		int blocksize =
1722 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1723 
1724 		if (blocksize < PAGE_CACHE_SIZE) {
1725 			ext4_msg(sb, KERN_ERR, "can't mount with "
1726 				 "dioread_nolock if block size != PAGE_SIZE");
1727 			return 0;
1728 		}
1729 	}
1730 	return 1;
1731 }
1732 
1733 static inline void ext4_show_quota_options(struct seq_file *seq,
1734 					   struct super_block *sb)
1735 {
1736 #if defined(CONFIG_QUOTA)
1737 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1738 
1739 	if (sbi->s_jquota_fmt) {
1740 		char *fmtname = "";
1741 
1742 		switch (sbi->s_jquota_fmt) {
1743 		case QFMT_VFS_OLD:
1744 			fmtname = "vfsold";
1745 			break;
1746 		case QFMT_VFS_V0:
1747 			fmtname = "vfsv0";
1748 			break;
1749 		case QFMT_VFS_V1:
1750 			fmtname = "vfsv1";
1751 			break;
1752 		}
1753 		seq_printf(seq, ",jqfmt=%s", fmtname);
1754 	}
1755 
1756 	if (sbi->s_qf_names[USRQUOTA])
1757 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1758 
1759 	if (sbi->s_qf_names[GRPQUOTA])
1760 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1761 #endif
1762 }
1763 
1764 static const char *token2str(int token)
1765 {
1766 	const struct match_token *t;
1767 
1768 	for (t = tokens; t->token != Opt_err; t++)
1769 		if (t->token == token && !strchr(t->pattern, '='))
1770 			break;
1771 	return t->pattern;
1772 }
1773 
1774 /*
1775  * Show an option if
1776  *  - it's set to a non-default value OR
1777  *  - if the per-sb default is different from the global default
1778  */
1779 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1780 			      int nodefs)
1781 {
1782 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1783 	struct ext4_super_block *es = sbi->s_es;
1784 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1785 	const struct mount_opts *m;
1786 	char sep = nodefs ? '\n' : ',';
1787 
1788 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1789 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1790 
1791 	if (sbi->s_sb_block != 1)
1792 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1793 
1794 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1795 		int want_set = m->flags & MOPT_SET;
1796 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1797 		    (m->flags & MOPT_CLEAR_ERR))
1798 			continue;
1799 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1800 			continue; /* skip if same as the default */
1801 		if ((want_set &&
1802 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1803 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1804 			continue; /* select Opt_noFoo vs Opt_Foo */
1805 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1806 	}
1807 
1808 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1809 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1810 		SEQ_OPTS_PRINT("resuid=%u",
1811 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1812 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1813 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1814 		SEQ_OPTS_PRINT("resgid=%u",
1815 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1816 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1817 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1818 		SEQ_OPTS_PUTS("errors=remount-ro");
1819 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1820 		SEQ_OPTS_PUTS("errors=continue");
1821 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1822 		SEQ_OPTS_PUTS("errors=panic");
1823 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1824 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1825 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1826 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1827 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1828 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1829 	if (sb->s_flags & MS_I_VERSION)
1830 		SEQ_OPTS_PUTS("i_version");
1831 	if (nodefs || sbi->s_stripe)
1832 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1833 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1834 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1835 			SEQ_OPTS_PUTS("data=journal");
1836 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1837 			SEQ_OPTS_PUTS("data=ordered");
1838 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1839 			SEQ_OPTS_PUTS("data=writeback");
1840 	}
1841 	if (nodefs ||
1842 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1843 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1844 			       sbi->s_inode_readahead_blks);
1845 
1846 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1847 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1848 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1849 	if (nodefs || sbi->s_max_dir_size_kb)
1850 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1851 
1852 	ext4_show_quota_options(seq, sb);
1853 	return 0;
1854 }
1855 
1856 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1857 {
1858 	return _ext4_show_options(seq, root->d_sb, 0);
1859 }
1860 
1861 static int options_seq_show(struct seq_file *seq, void *offset)
1862 {
1863 	struct super_block *sb = seq->private;
1864 	int rc;
1865 
1866 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1867 	rc = _ext4_show_options(seq, sb, 1);
1868 	seq_puts(seq, "\n");
1869 	return rc;
1870 }
1871 
1872 static int options_open_fs(struct inode *inode, struct file *file)
1873 {
1874 	return single_open(file, options_seq_show, PDE_DATA(inode));
1875 }
1876 
1877 static const struct file_operations ext4_seq_options_fops = {
1878 	.owner = THIS_MODULE,
1879 	.open = options_open_fs,
1880 	.read = seq_read,
1881 	.llseek = seq_lseek,
1882 	.release = single_release,
1883 };
1884 
1885 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1886 			    int read_only)
1887 {
1888 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1889 	int res = 0;
1890 
1891 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1892 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1893 			 "forcing read-only mode");
1894 		res = MS_RDONLY;
1895 	}
1896 	if (read_only)
1897 		goto done;
1898 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1899 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1900 			 "running e2fsck is recommended");
1901 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1902 		ext4_msg(sb, KERN_WARNING,
1903 			 "warning: mounting fs with errors, "
1904 			 "running e2fsck is recommended");
1905 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1906 		 le16_to_cpu(es->s_mnt_count) >=
1907 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1908 		ext4_msg(sb, KERN_WARNING,
1909 			 "warning: maximal mount count reached, "
1910 			 "running e2fsck is recommended");
1911 	else if (le32_to_cpu(es->s_checkinterval) &&
1912 		(le32_to_cpu(es->s_lastcheck) +
1913 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1914 		ext4_msg(sb, KERN_WARNING,
1915 			 "warning: checktime reached, "
1916 			 "running e2fsck is recommended");
1917 	if (!sbi->s_journal)
1918 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1919 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1920 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1921 	le16_add_cpu(&es->s_mnt_count, 1);
1922 	es->s_mtime = cpu_to_le32(get_seconds());
1923 	ext4_update_dynamic_rev(sb);
1924 	if (sbi->s_journal)
1925 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1926 
1927 	ext4_commit_super(sb, 1);
1928 done:
1929 	if (test_opt(sb, DEBUG))
1930 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1931 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1932 			sb->s_blocksize,
1933 			sbi->s_groups_count,
1934 			EXT4_BLOCKS_PER_GROUP(sb),
1935 			EXT4_INODES_PER_GROUP(sb),
1936 			sbi->s_mount_opt, sbi->s_mount_opt2);
1937 
1938 	cleancache_init_fs(sb);
1939 	return res;
1940 }
1941 
1942 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1943 {
1944 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1945 	struct flex_groups *new_groups;
1946 	int size;
1947 
1948 	if (!sbi->s_log_groups_per_flex)
1949 		return 0;
1950 
1951 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
1952 	if (size <= sbi->s_flex_groups_allocated)
1953 		return 0;
1954 
1955 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1956 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1957 	if (!new_groups) {
1958 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1959 			 size / (int) sizeof(struct flex_groups));
1960 		return -ENOMEM;
1961 	}
1962 
1963 	if (sbi->s_flex_groups) {
1964 		memcpy(new_groups, sbi->s_flex_groups,
1965 		       (sbi->s_flex_groups_allocated *
1966 			sizeof(struct flex_groups)));
1967 		ext4_kvfree(sbi->s_flex_groups);
1968 	}
1969 	sbi->s_flex_groups = new_groups;
1970 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1971 	return 0;
1972 }
1973 
1974 static int ext4_fill_flex_info(struct super_block *sb)
1975 {
1976 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1977 	struct ext4_group_desc *gdp = NULL;
1978 	ext4_group_t flex_group;
1979 	int i, err;
1980 
1981 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1982 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1983 		sbi->s_log_groups_per_flex = 0;
1984 		return 1;
1985 	}
1986 
1987 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1988 	if (err)
1989 		goto failed;
1990 
1991 	for (i = 0; i < sbi->s_groups_count; i++) {
1992 		gdp = ext4_get_group_desc(sb, i, NULL);
1993 
1994 		flex_group = ext4_flex_group(sbi, i);
1995 		atomic_add(ext4_free_inodes_count(sb, gdp),
1996 			   &sbi->s_flex_groups[flex_group].free_inodes);
1997 		atomic64_add(ext4_free_group_clusters(sb, gdp),
1998 			     &sbi->s_flex_groups[flex_group].free_clusters);
1999 		atomic_add(ext4_used_dirs_count(sb, gdp),
2000 			   &sbi->s_flex_groups[flex_group].used_dirs);
2001 	}
2002 
2003 	return 1;
2004 failed:
2005 	return 0;
2006 }
2007 
2008 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2009 				   struct ext4_group_desc *gdp)
2010 {
2011 	int offset;
2012 	__u16 crc = 0;
2013 	__le32 le_group = cpu_to_le32(block_group);
2014 
2015 	if ((sbi->s_es->s_feature_ro_compat &
2016 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
2017 		/* Use new metadata_csum algorithm */
2018 		__le16 save_csum;
2019 		__u32 csum32;
2020 
2021 		save_csum = gdp->bg_checksum;
2022 		gdp->bg_checksum = 0;
2023 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2024 				     sizeof(le_group));
2025 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2026 				     sbi->s_desc_size);
2027 		gdp->bg_checksum = save_csum;
2028 
2029 		crc = csum32 & 0xFFFF;
2030 		goto out;
2031 	}
2032 
2033 	/* old crc16 code */
2034 	offset = offsetof(struct ext4_group_desc, bg_checksum);
2035 
2036 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2037 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2038 	crc = crc16(crc, (__u8 *)gdp, offset);
2039 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2040 	/* for checksum of struct ext4_group_desc do the rest...*/
2041 	if ((sbi->s_es->s_feature_incompat &
2042 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2043 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2044 		crc = crc16(crc, (__u8 *)gdp + offset,
2045 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2046 				offset);
2047 
2048 out:
2049 	return cpu_to_le16(crc);
2050 }
2051 
2052 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2053 				struct ext4_group_desc *gdp)
2054 {
2055 	if (ext4_has_group_desc_csum(sb) &&
2056 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2057 						      block_group, gdp)))
2058 		return 0;
2059 
2060 	return 1;
2061 }
2062 
2063 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2064 			      struct ext4_group_desc *gdp)
2065 {
2066 	if (!ext4_has_group_desc_csum(sb))
2067 		return;
2068 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2069 }
2070 
2071 /* Called at mount-time, super-block is locked */
2072 static int ext4_check_descriptors(struct super_block *sb,
2073 				  ext4_group_t *first_not_zeroed)
2074 {
2075 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2076 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2077 	ext4_fsblk_t last_block;
2078 	ext4_fsblk_t block_bitmap;
2079 	ext4_fsblk_t inode_bitmap;
2080 	ext4_fsblk_t inode_table;
2081 	int flexbg_flag = 0;
2082 	ext4_group_t i, grp = sbi->s_groups_count;
2083 
2084 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2085 		flexbg_flag = 1;
2086 
2087 	ext4_debug("Checking group descriptors");
2088 
2089 	for (i = 0; i < sbi->s_groups_count; i++) {
2090 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2091 
2092 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2093 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2094 		else
2095 			last_block = first_block +
2096 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2097 
2098 		if ((grp == sbi->s_groups_count) &&
2099 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2100 			grp = i;
2101 
2102 		block_bitmap = ext4_block_bitmap(sb, gdp);
2103 		if (block_bitmap < first_block || block_bitmap > last_block) {
2104 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2105 			       "Block bitmap for group %u not in group "
2106 			       "(block %llu)!", i, block_bitmap);
2107 			return 0;
2108 		}
2109 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2110 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2111 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2112 			       "Inode bitmap for group %u not in group "
2113 			       "(block %llu)!", i, inode_bitmap);
2114 			return 0;
2115 		}
2116 		inode_table = ext4_inode_table(sb, gdp);
2117 		if (inode_table < first_block ||
2118 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2119 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2120 			       "Inode table for group %u not in group "
2121 			       "(block %llu)!", i, inode_table);
2122 			return 0;
2123 		}
2124 		ext4_lock_group(sb, i);
2125 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2126 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2127 				 "Checksum for group %u failed (%u!=%u)",
2128 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2129 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2130 			if (!(sb->s_flags & MS_RDONLY)) {
2131 				ext4_unlock_group(sb, i);
2132 				return 0;
2133 			}
2134 		}
2135 		ext4_unlock_group(sb, i);
2136 		if (!flexbg_flag)
2137 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2138 	}
2139 	if (NULL != first_not_zeroed)
2140 		*first_not_zeroed = grp;
2141 
2142 	ext4_free_blocks_count_set(sbi->s_es,
2143 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2144 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2145 	return 1;
2146 }
2147 
2148 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2149  * the superblock) which were deleted from all directories, but held open by
2150  * a process at the time of a crash.  We walk the list and try to delete these
2151  * inodes at recovery time (only with a read-write filesystem).
2152  *
2153  * In order to keep the orphan inode chain consistent during traversal (in
2154  * case of crash during recovery), we link each inode into the superblock
2155  * orphan list_head and handle it the same way as an inode deletion during
2156  * normal operation (which journals the operations for us).
2157  *
2158  * We only do an iget() and an iput() on each inode, which is very safe if we
2159  * accidentally point at an in-use or already deleted inode.  The worst that
2160  * can happen in this case is that we get a "bit already cleared" message from
2161  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2162  * e2fsck was run on this filesystem, and it must have already done the orphan
2163  * inode cleanup for us, so we can safely abort without any further action.
2164  */
2165 static void ext4_orphan_cleanup(struct super_block *sb,
2166 				struct ext4_super_block *es)
2167 {
2168 	unsigned int s_flags = sb->s_flags;
2169 	int nr_orphans = 0, nr_truncates = 0;
2170 #ifdef CONFIG_QUOTA
2171 	int i;
2172 #endif
2173 	if (!es->s_last_orphan) {
2174 		jbd_debug(4, "no orphan inodes to clean up\n");
2175 		return;
2176 	}
2177 
2178 	if (bdev_read_only(sb->s_bdev)) {
2179 		ext4_msg(sb, KERN_ERR, "write access "
2180 			"unavailable, skipping orphan cleanup");
2181 		return;
2182 	}
2183 
2184 	/* Check if feature set would not allow a r/w mount */
2185 	if (!ext4_feature_set_ok(sb, 0)) {
2186 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2187 			 "unknown ROCOMPAT features");
2188 		return;
2189 	}
2190 
2191 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2192 		/* don't clear list on RO mount w/ errors */
2193 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2194 			jbd_debug(1, "Errors on filesystem, "
2195 				  "clearing orphan list.\n");
2196 			es->s_last_orphan = 0;
2197 		}
2198 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2199 		return;
2200 	}
2201 
2202 	if (s_flags & MS_RDONLY) {
2203 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2204 		sb->s_flags &= ~MS_RDONLY;
2205 	}
2206 #ifdef CONFIG_QUOTA
2207 	/* Needed for iput() to work correctly and not trash data */
2208 	sb->s_flags |= MS_ACTIVE;
2209 	/* Turn on quotas so that they are updated correctly */
2210 	for (i = 0; i < MAXQUOTAS; i++) {
2211 		if (EXT4_SB(sb)->s_qf_names[i]) {
2212 			int ret = ext4_quota_on_mount(sb, i);
2213 			if (ret < 0)
2214 				ext4_msg(sb, KERN_ERR,
2215 					"Cannot turn on journaled "
2216 					"quota: error %d", ret);
2217 		}
2218 	}
2219 #endif
2220 
2221 	while (es->s_last_orphan) {
2222 		struct inode *inode;
2223 
2224 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2225 		if (IS_ERR(inode)) {
2226 			es->s_last_orphan = 0;
2227 			break;
2228 		}
2229 
2230 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2231 		dquot_initialize(inode);
2232 		if (inode->i_nlink) {
2233 			if (test_opt(sb, DEBUG))
2234 				ext4_msg(sb, KERN_DEBUG,
2235 					"%s: truncating inode %lu to %lld bytes",
2236 					__func__, inode->i_ino, inode->i_size);
2237 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2238 				  inode->i_ino, inode->i_size);
2239 			mutex_lock(&inode->i_mutex);
2240 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2241 			ext4_truncate(inode);
2242 			mutex_unlock(&inode->i_mutex);
2243 			nr_truncates++;
2244 		} else {
2245 			if (test_opt(sb, DEBUG))
2246 				ext4_msg(sb, KERN_DEBUG,
2247 					"%s: deleting unreferenced inode %lu",
2248 					__func__, inode->i_ino);
2249 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2250 				  inode->i_ino);
2251 			nr_orphans++;
2252 		}
2253 		iput(inode);  /* The delete magic happens here! */
2254 	}
2255 
2256 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2257 
2258 	if (nr_orphans)
2259 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2260 		       PLURAL(nr_orphans));
2261 	if (nr_truncates)
2262 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2263 		       PLURAL(nr_truncates));
2264 #ifdef CONFIG_QUOTA
2265 	/* Turn quotas off */
2266 	for (i = 0; i < MAXQUOTAS; i++) {
2267 		if (sb_dqopt(sb)->files[i])
2268 			dquot_quota_off(sb, i);
2269 	}
2270 #endif
2271 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2272 }
2273 
2274 /*
2275  * Maximal extent format file size.
2276  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2277  * extent format containers, within a sector_t, and within i_blocks
2278  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2279  * so that won't be a limiting factor.
2280  *
2281  * However there is other limiting factor. We do store extents in the form
2282  * of starting block and length, hence the resulting length of the extent
2283  * covering maximum file size must fit into on-disk format containers as
2284  * well. Given that length is always by 1 unit bigger than max unit (because
2285  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2286  *
2287  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2288  */
2289 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2290 {
2291 	loff_t res;
2292 	loff_t upper_limit = MAX_LFS_FILESIZE;
2293 
2294 	/* small i_blocks in vfs inode? */
2295 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2296 		/*
2297 		 * CONFIG_LBDAF is not enabled implies the inode
2298 		 * i_block represent total blocks in 512 bytes
2299 		 * 32 == size of vfs inode i_blocks * 8
2300 		 */
2301 		upper_limit = (1LL << 32) - 1;
2302 
2303 		/* total blocks in file system block size */
2304 		upper_limit >>= (blkbits - 9);
2305 		upper_limit <<= blkbits;
2306 	}
2307 
2308 	/*
2309 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2310 	 * by one fs block, so ee_len can cover the extent of maximum file
2311 	 * size
2312 	 */
2313 	res = (1LL << 32) - 1;
2314 	res <<= blkbits;
2315 
2316 	/* Sanity check against vm- & vfs- imposed limits */
2317 	if (res > upper_limit)
2318 		res = upper_limit;
2319 
2320 	return res;
2321 }
2322 
2323 /*
2324  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2325  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2326  * We need to be 1 filesystem block less than the 2^48 sector limit.
2327  */
2328 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2329 {
2330 	loff_t res = EXT4_NDIR_BLOCKS;
2331 	int meta_blocks;
2332 	loff_t upper_limit;
2333 	/* This is calculated to be the largest file size for a dense, block
2334 	 * mapped file such that the file's total number of 512-byte sectors,
2335 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2336 	 *
2337 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2338 	 * number of 512-byte sectors of the file.
2339 	 */
2340 
2341 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2342 		/*
2343 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2344 		 * the inode i_block field represents total file blocks in
2345 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2346 		 */
2347 		upper_limit = (1LL << 32) - 1;
2348 
2349 		/* total blocks in file system block size */
2350 		upper_limit >>= (bits - 9);
2351 
2352 	} else {
2353 		/*
2354 		 * We use 48 bit ext4_inode i_blocks
2355 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2356 		 * represent total number of blocks in
2357 		 * file system block size
2358 		 */
2359 		upper_limit = (1LL << 48) - 1;
2360 
2361 	}
2362 
2363 	/* indirect blocks */
2364 	meta_blocks = 1;
2365 	/* double indirect blocks */
2366 	meta_blocks += 1 + (1LL << (bits-2));
2367 	/* tripple indirect blocks */
2368 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2369 
2370 	upper_limit -= meta_blocks;
2371 	upper_limit <<= bits;
2372 
2373 	res += 1LL << (bits-2);
2374 	res += 1LL << (2*(bits-2));
2375 	res += 1LL << (3*(bits-2));
2376 	res <<= bits;
2377 	if (res > upper_limit)
2378 		res = upper_limit;
2379 
2380 	if (res > MAX_LFS_FILESIZE)
2381 		res = MAX_LFS_FILESIZE;
2382 
2383 	return res;
2384 }
2385 
2386 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2387 				   ext4_fsblk_t logical_sb_block, int nr)
2388 {
2389 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2390 	ext4_group_t bg, first_meta_bg;
2391 	int has_super = 0;
2392 
2393 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2394 
2395 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2396 	    nr < first_meta_bg)
2397 		return logical_sb_block + nr + 1;
2398 	bg = sbi->s_desc_per_block * nr;
2399 	if (ext4_bg_has_super(sb, bg))
2400 		has_super = 1;
2401 
2402 	return (has_super + ext4_group_first_block_no(sb, bg));
2403 }
2404 
2405 /**
2406  * ext4_get_stripe_size: Get the stripe size.
2407  * @sbi: In memory super block info
2408  *
2409  * If we have specified it via mount option, then
2410  * use the mount option value. If the value specified at mount time is
2411  * greater than the blocks per group use the super block value.
2412  * If the super block value is greater than blocks per group return 0.
2413  * Allocator needs it be less than blocks per group.
2414  *
2415  */
2416 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2417 {
2418 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2419 	unsigned long stripe_width =
2420 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2421 	int ret;
2422 
2423 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2424 		ret = sbi->s_stripe;
2425 	else if (stripe_width <= sbi->s_blocks_per_group)
2426 		ret = stripe_width;
2427 	else if (stride <= sbi->s_blocks_per_group)
2428 		ret = stride;
2429 	else
2430 		ret = 0;
2431 
2432 	/*
2433 	 * If the stripe width is 1, this makes no sense and
2434 	 * we set it to 0 to turn off stripe handling code.
2435 	 */
2436 	if (ret <= 1)
2437 		ret = 0;
2438 
2439 	return ret;
2440 }
2441 
2442 /* sysfs supprt */
2443 
2444 struct ext4_attr {
2445 	struct attribute attr;
2446 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2447 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2448 			 const char *, size_t);
2449 	union {
2450 		int offset;
2451 		int deprecated_val;
2452 	} u;
2453 };
2454 
2455 static int parse_strtoull(const char *buf,
2456 		unsigned long long max, unsigned long long *value)
2457 {
2458 	int ret;
2459 
2460 	ret = kstrtoull(skip_spaces(buf), 0, value);
2461 	if (!ret && *value > max)
2462 		ret = -EINVAL;
2463 	return ret;
2464 }
2465 
2466 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2467 					      struct ext4_sb_info *sbi,
2468 					      char *buf)
2469 {
2470 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2471 		(s64) EXT4_C2B(sbi,
2472 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2473 }
2474 
2475 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2476 					 struct ext4_sb_info *sbi, char *buf)
2477 {
2478 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2479 
2480 	if (!sb->s_bdev->bd_part)
2481 		return snprintf(buf, PAGE_SIZE, "0\n");
2482 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2483 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2484 			 sbi->s_sectors_written_start) >> 1);
2485 }
2486 
2487 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2488 					  struct ext4_sb_info *sbi, char *buf)
2489 {
2490 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2491 
2492 	if (!sb->s_bdev->bd_part)
2493 		return snprintf(buf, PAGE_SIZE, "0\n");
2494 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2495 			(unsigned long long)(sbi->s_kbytes_written +
2496 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2497 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2498 }
2499 
2500 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2501 					  struct ext4_sb_info *sbi,
2502 					  const char *buf, size_t count)
2503 {
2504 	unsigned long t;
2505 	int ret;
2506 
2507 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2508 	if (ret)
2509 		return ret;
2510 
2511 	if (t && (!is_power_of_2(t) || t > 0x40000000))
2512 		return -EINVAL;
2513 
2514 	sbi->s_inode_readahead_blks = t;
2515 	return count;
2516 }
2517 
2518 static ssize_t sbi_ui_show(struct ext4_attr *a,
2519 			   struct ext4_sb_info *sbi, char *buf)
2520 {
2521 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2522 
2523 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2524 }
2525 
2526 static ssize_t sbi_ui_store(struct ext4_attr *a,
2527 			    struct ext4_sb_info *sbi,
2528 			    const char *buf, size_t count)
2529 {
2530 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2531 	unsigned long t;
2532 	int ret;
2533 
2534 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2535 	if (ret)
2536 		return ret;
2537 	*ui = t;
2538 	return count;
2539 }
2540 
2541 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2542 				  struct ext4_sb_info *sbi, char *buf)
2543 {
2544 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2545 		(unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2546 }
2547 
2548 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2549 				   struct ext4_sb_info *sbi,
2550 				   const char *buf, size_t count)
2551 {
2552 	unsigned long long val;
2553 	int ret;
2554 
2555 	if (parse_strtoull(buf, -1ULL, &val))
2556 		return -EINVAL;
2557 	ret = ext4_reserve_clusters(sbi, val);
2558 
2559 	return ret ? ret : count;
2560 }
2561 
2562 static ssize_t trigger_test_error(struct ext4_attr *a,
2563 				  struct ext4_sb_info *sbi,
2564 				  const char *buf, size_t count)
2565 {
2566 	int len = count;
2567 
2568 	if (!capable(CAP_SYS_ADMIN))
2569 		return -EPERM;
2570 
2571 	if (len && buf[len-1] == '\n')
2572 		len--;
2573 
2574 	if (len)
2575 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2576 	return count;
2577 }
2578 
2579 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2580 				   struct ext4_sb_info *sbi, char *buf)
2581 {
2582 	return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2583 }
2584 
2585 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2586 static struct ext4_attr ext4_attr_##_name = {			\
2587 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2588 	.show	= _show,					\
2589 	.store	= _store,					\
2590 	.u = {							\
2591 		.offset = offsetof(struct ext4_sb_info, _elname),\
2592 	},							\
2593 }
2594 #define EXT4_ATTR(name, mode, show, store) \
2595 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2596 
2597 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2598 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2599 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2600 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2601 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2602 #define ATTR_LIST(name) &ext4_attr_##name.attr
2603 #define EXT4_DEPRECATED_ATTR(_name, _val)	\
2604 static struct ext4_attr ext4_attr_##_name = {			\
2605 	.attr = {.name = __stringify(_name), .mode = 0444 },	\
2606 	.show	= sbi_deprecated_show,				\
2607 	.u = {							\
2608 		.deprecated_val = _val,				\
2609 	},							\
2610 }
2611 
2612 EXT4_RO_ATTR(delayed_allocation_blocks);
2613 EXT4_RO_ATTR(session_write_kbytes);
2614 EXT4_RO_ATTR(lifetime_write_kbytes);
2615 EXT4_RW_ATTR(reserved_clusters);
2616 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2617 		 inode_readahead_blks_store, s_inode_readahead_blks);
2618 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2619 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2620 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2621 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2622 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2623 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2624 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2625 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2626 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2627 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2628 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2629 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2630 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2631 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2632 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2633 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2634 
2635 static struct attribute *ext4_attrs[] = {
2636 	ATTR_LIST(delayed_allocation_blocks),
2637 	ATTR_LIST(session_write_kbytes),
2638 	ATTR_LIST(lifetime_write_kbytes),
2639 	ATTR_LIST(reserved_clusters),
2640 	ATTR_LIST(inode_readahead_blks),
2641 	ATTR_LIST(inode_goal),
2642 	ATTR_LIST(mb_stats),
2643 	ATTR_LIST(mb_max_to_scan),
2644 	ATTR_LIST(mb_min_to_scan),
2645 	ATTR_LIST(mb_order2_req),
2646 	ATTR_LIST(mb_stream_req),
2647 	ATTR_LIST(mb_group_prealloc),
2648 	ATTR_LIST(max_writeback_mb_bump),
2649 	ATTR_LIST(extent_max_zeroout_kb),
2650 	ATTR_LIST(trigger_fs_error),
2651 	ATTR_LIST(err_ratelimit_interval_ms),
2652 	ATTR_LIST(err_ratelimit_burst),
2653 	ATTR_LIST(warning_ratelimit_interval_ms),
2654 	ATTR_LIST(warning_ratelimit_burst),
2655 	ATTR_LIST(msg_ratelimit_interval_ms),
2656 	ATTR_LIST(msg_ratelimit_burst),
2657 	NULL,
2658 };
2659 
2660 /* Features this copy of ext4 supports */
2661 EXT4_INFO_ATTR(lazy_itable_init);
2662 EXT4_INFO_ATTR(batched_discard);
2663 EXT4_INFO_ATTR(meta_bg_resize);
2664 
2665 static struct attribute *ext4_feat_attrs[] = {
2666 	ATTR_LIST(lazy_itable_init),
2667 	ATTR_LIST(batched_discard),
2668 	ATTR_LIST(meta_bg_resize),
2669 	NULL,
2670 };
2671 
2672 static ssize_t ext4_attr_show(struct kobject *kobj,
2673 			      struct attribute *attr, char *buf)
2674 {
2675 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2676 						s_kobj);
2677 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2678 
2679 	return a->show ? a->show(a, sbi, buf) : 0;
2680 }
2681 
2682 static ssize_t ext4_attr_store(struct kobject *kobj,
2683 			       struct attribute *attr,
2684 			       const char *buf, size_t len)
2685 {
2686 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2687 						s_kobj);
2688 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2689 
2690 	return a->store ? a->store(a, sbi, buf, len) : 0;
2691 }
2692 
2693 static void ext4_sb_release(struct kobject *kobj)
2694 {
2695 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2696 						s_kobj);
2697 	complete(&sbi->s_kobj_unregister);
2698 }
2699 
2700 static const struct sysfs_ops ext4_attr_ops = {
2701 	.show	= ext4_attr_show,
2702 	.store	= ext4_attr_store,
2703 };
2704 
2705 static struct kobj_type ext4_ktype = {
2706 	.default_attrs	= ext4_attrs,
2707 	.sysfs_ops	= &ext4_attr_ops,
2708 	.release	= ext4_sb_release,
2709 };
2710 
2711 static void ext4_feat_release(struct kobject *kobj)
2712 {
2713 	complete(&ext4_feat->f_kobj_unregister);
2714 }
2715 
2716 static struct kobj_type ext4_feat_ktype = {
2717 	.default_attrs	= ext4_feat_attrs,
2718 	.sysfs_ops	= &ext4_attr_ops,
2719 	.release	= ext4_feat_release,
2720 };
2721 
2722 /*
2723  * Check whether this filesystem can be mounted based on
2724  * the features present and the RDONLY/RDWR mount requested.
2725  * Returns 1 if this filesystem can be mounted as requested,
2726  * 0 if it cannot be.
2727  */
2728 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2729 {
2730 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2731 		ext4_msg(sb, KERN_ERR,
2732 			"Couldn't mount because of "
2733 			"unsupported optional features (%x)",
2734 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2735 			~EXT4_FEATURE_INCOMPAT_SUPP));
2736 		return 0;
2737 	}
2738 
2739 	if (readonly)
2740 		return 1;
2741 
2742 	/* Check that feature set is OK for a read-write mount */
2743 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2744 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2745 			 "unsupported optional features (%x)",
2746 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2747 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2748 		return 0;
2749 	}
2750 	/*
2751 	 * Large file size enabled file system can only be mounted
2752 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2753 	 */
2754 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2755 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2756 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2757 				 "cannot be mounted RDWR without "
2758 				 "CONFIG_LBDAF");
2759 			return 0;
2760 		}
2761 	}
2762 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2763 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2764 		ext4_msg(sb, KERN_ERR,
2765 			 "Can't support bigalloc feature without "
2766 			 "extents feature\n");
2767 		return 0;
2768 	}
2769 
2770 #ifndef CONFIG_QUOTA
2771 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2772 	    !readonly) {
2773 		ext4_msg(sb, KERN_ERR,
2774 			 "Filesystem with quota feature cannot be mounted RDWR "
2775 			 "without CONFIG_QUOTA");
2776 		return 0;
2777 	}
2778 #endif  /* CONFIG_QUOTA */
2779 	return 1;
2780 }
2781 
2782 /*
2783  * This function is called once a day if we have errors logged
2784  * on the file system
2785  */
2786 static void print_daily_error_info(unsigned long arg)
2787 {
2788 	struct super_block *sb = (struct super_block *) arg;
2789 	struct ext4_sb_info *sbi;
2790 	struct ext4_super_block *es;
2791 
2792 	sbi = EXT4_SB(sb);
2793 	es = sbi->s_es;
2794 
2795 	if (es->s_error_count)
2796 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2797 			 le32_to_cpu(es->s_error_count));
2798 	if (es->s_first_error_time) {
2799 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2800 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2801 		       (int) sizeof(es->s_first_error_func),
2802 		       es->s_first_error_func,
2803 		       le32_to_cpu(es->s_first_error_line));
2804 		if (es->s_first_error_ino)
2805 			printk(": inode %u",
2806 			       le32_to_cpu(es->s_first_error_ino));
2807 		if (es->s_first_error_block)
2808 			printk(": block %llu", (unsigned long long)
2809 			       le64_to_cpu(es->s_first_error_block));
2810 		printk("\n");
2811 	}
2812 	if (es->s_last_error_time) {
2813 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2814 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2815 		       (int) sizeof(es->s_last_error_func),
2816 		       es->s_last_error_func,
2817 		       le32_to_cpu(es->s_last_error_line));
2818 		if (es->s_last_error_ino)
2819 			printk(": inode %u",
2820 			       le32_to_cpu(es->s_last_error_ino));
2821 		if (es->s_last_error_block)
2822 			printk(": block %llu", (unsigned long long)
2823 			       le64_to_cpu(es->s_last_error_block));
2824 		printk("\n");
2825 	}
2826 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2827 }
2828 
2829 /* Find next suitable group and run ext4_init_inode_table */
2830 static int ext4_run_li_request(struct ext4_li_request *elr)
2831 {
2832 	struct ext4_group_desc *gdp = NULL;
2833 	ext4_group_t group, ngroups;
2834 	struct super_block *sb;
2835 	unsigned long timeout = 0;
2836 	int ret = 0;
2837 
2838 	sb = elr->lr_super;
2839 	ngroups = EXT4_SB(sb)->s_groups_count;
2840 
2841 	sb_start_write(sb);
2842 	for (group = elr->lr_next_group; group < ngroups; group++) {
2843 		gdp = ext4_get_group_desc(sb, group, NULL);
2844 		if (!gdp) {
2845 			ret = 1;
2846 			break;
2847 		}
2848 
2849 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2850 			break;
2851 	}
2852 
2853 	if (group >= ngroups)
2854 		ret = 1;
2855 
2856 	if (!ret) {
2857 		timeout = jiffies;
2858 		ret = ext4_init_inode_table(sb, group,
2859 					    elr->lr_timeout ? 0 : 1);
2860 		if (elr->lr_timeout == 0) {
2861 			timeout = (jiffies - timeout) *
2862 				  elr->lr_sbi->s_li_wait_mult;
2863 			elr->lr_timeout = timeout;
2864 		}
2865 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2866 		elr->lr_next_group = group + 1;
2867 	}
2868 	sb_end_write(sb);
2869 
2870 	return ret;
2871 }
2872 
2873 /*
2874  * Remove lr_request from the list_request and free the
2875  * request structure. Should be called with li_list_mtx held
2876  */
2877 static void ext4_remove_li_request(struct ext4_li_request *elr)
2878 {
2879 	struct ext4_sb_info *sbi;
2880 
2881 	if (!elr)
2882 		return;
2883 
2884 	sbi = elr->lr_sbi;
2885 
2886 	list_del(&elr->lr_request);
2887 	sbi->s_li_request = NULL;
2888 	kfree(elr);
2889 }
2890 
2891 static void ext4_unregister_li_request(struct super_block *sb)
2892 {
2893 	mutex_lock(&ext4_li_mtx);
2894 	if (!ext4_li_info) {
2895 		mutex_unlock(&ext4_li_mtx);
2896 		return;
2897 	}
2898 
2899 	mutex_lock(&ext4_li_info->li_list_mtx);
2900 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2901 	mutex_unlock(&ext4_li_info->li_list_mtx);
2902 	mutex_unlock(&ext4_li_mtx);
2903 }
2904 
2905 static struct task_struct *ext4_lazyinit_task;
2906 
2907 /*
2908  * This is the function where ext4lazyinit thread lives. It walks
2909  * through the request list searching for next scheduled filesystem.
2910  * When such a fs is found, run the lazy initialization request
2911  * (ext4_rn_li_request) and keep track of the time spend in this
2912  * function. Based on that time we compute next schedule time of
2913  * the request. When walking through the list is complete, compute
2914  * next waking time and put itself into sleep.
2915  */
2916 static int ext4_lazyinit_thread(void *arg)
2917 {
2918 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2919 	struct list_head *pos, *n;
2920 	struct ext4_li_request *elr;
2921 	unsigned long next_wakeup, cur;
2922 
2923 	BUG_ON(NULL == eli);
2924 
2925 cont_thread:
2926 	while (true) {
2927 		next_wakeup = MAX_JIFFY_OFFSET;
2928 
2929 		mutex_lock(&eli->li_list_mtx);
2930 		if (list_empty(&eli->li_request_list)) {
2931 			mutex_unlock(&eli->li_list_mtx);
2932 			goto exit_thread;
2933 		}
2934 
2935 		list_for_each_safe(pos, n, &eli->li_request_list) {
2936 			elr = list_entry(pos, struct ext4_li_request,
2937 					 lr_request);
2938 
2939 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2940 				if (ext4_run_li_request(elr) != 0) {
2941 					/* error, remove the lazy_init job */
2942 					ext4_remove_li_request(elr);
2943 					continue;
2944 				}
2945 			}
2946 
2947 			if (time_before(elr->lr_next_sched, next_wakeup))
2948 				next_wakeup = elr->lr_next_sched;
2949 		}
2950 		mutex_unlock(&eli->li_list_mtx);
2951 
2952 		try_to_freeze();
2953 
2954 		cur = jiffies;
2955 		if ((time_after_eq(cur, next_wakeup)) ||
2956 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2957 			cond_resched();
2958 			continue;
2959 		}
2960 
2961 		schedule_timeout_interruptible(next_wakeup - cur);
2962 
2963 		if (kthread_should_stop()) {
2964 			ext4_clear_request_list();
2965 			goto exit_thread;
2966 		}
2967 	}
2968 
2969 exit_thread:
2970 	/*
2971 	 * It looks like the request list is empty, but we need
2972 	 * to check it under the li_list_mtx lock, to prevent any
2973 	 * additions into it, and of course we should lock ext4_li_mtx
2974 	 * to atomically free the list and ext4_li_info, because at
2975 	 * this point another ext4 filesystem could be registering
2976 	 * new one.
2977 	 */
2978 	mutex_lock(&ext4_li_mtx);
2979 	mutex_lock(&eli->li_list_mtx);
2980 	if (!list_empty(&eli->li_request_list)) {
2981 		mutex_unlock(&eli->li_list_mtx);
2982 		mutex_unlock(&ext4_li_mtx);
2983 		goto cont_thread;
2984 	}
2985 	mutex_unlock(&eli->li_list_mtx);
2986 	kfree(ext4_li_info);
2987 	ext4_li_info = NULL;
2988 	mutex_unlock(&ext4_li_mtx);
2989 
2990 	return 0;
2991 }
2992 
2993 static void ext4_clear_request_list(void)
2994 {
2995 	struct list_head *pos, *n;
2996 	struct ext4_li_request *elr;
2997 
2998 	mutex_lock(&ext4_li_info->li_list_mtx);
2999 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3000 		elr = list_entry(pos, struct ext4_li_request,
3001 				 lr_request);
3002 		ext4_remove_li_request(elr);
3003 	}
3004 	mutex_unlock(&ext4_li_info->li_list_mtx);
3005 }
3006 
3007 static int ext4_run_lazyinit_thread(void)
3008 {
3009 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3010 					 ext4_li_info, "ext4lazyinit");
3011 	if (IS_ERR(ext4_lazyinit_task)) {
3012 		int err = PTR_ERR(ext4_lazyinit_task);
3013 		ext4_clear_request_list();
3014 		kfree(ext4_li_info);
3015 		ext4_li_info = NULL;
3016 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3017 				 "initialization thread\n",
3018 				 err);
3019 		return err;
3020 	}
3021 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3022 	return 0;
3023 }
3024 
3025 /*
3026  * Check whether it make sense to run itable init. thread or not.
3027  * If there is at least one uninitialized inode table, return
3028  * corresponding group number, else the loop goes through all
3029  * groups and return total number of groups.
3030  */
3031 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3032 {
3033 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3034 	struct ext4_group_desc *gdp = NULL;
3035 
3036 	for (group = 0; group < ngroups; group++) {
3037 		gdp = ext4_get_group_desc(sb, group, NULL);
3038 		if (!gdp)
3039 			continue;
3040 
3041 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3042 			break;
3043 	}
3044 
3045 	return group;
3046 }
3047 
3048 static int ext4_li_info_new(void)
3049 {
3050 	struct ext4_lazy_init *eli = NULL;
3051 
3052 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3053 	if (!eli)
3054 		return -ENOMEM;
3055 
3056 	INIT_LIST_HEAD(&eli->li_request_list);
3057 	mutex_init(&eli->li_list_mtx);
3058 
3059 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3060 
3061 	ext4_li_info = eli;
3062 
3063 	return 0;
3064 }
3065 
3066 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3067 					    ext4_group_t start)
3068 {
3069 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3070 	struct ext4_li_request *elr;
3071 
3072 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3073 	if (!elr)
3074 		return NULL;
3075 
3076 	elr->lr_super = sb;
3077 	elr->lr_sbi = sbi;
3078 	elr->lr_next_group = start;
3079 
3080 	/*
3081 	 * Randomize first schedule time of the request to
3082 	 * spread the inode table initialization requests
3083 	 * better.
3084 	 */
3085 	elr->lr_next_sched = jiffies + (prandom_u32() %
3086 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3087 	return elr;
3088 }
3089 
3090 int ext4_register_li_request(struct super_block *sb,
3091 			     ext4_group_t first_not_zeroed)
3092 {
3093 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3094 	struct ext4_li_request *elr = NULL;
3095 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3096 	int ret = 0;
3097 
3098 	mutex_lock(&ext4_li_mtx);
3099 	if (sbi->s_li_request != NULL) {
3100 		/*
3101 		 * Reset timeout so it can be computed again, because
3102 		 * s_li_wait_mult might have changed.
3103 		 */
3104 		sbi->s_li_request->lr_timeout = 0;
3105 		goto out;
3106 	}
3107 
3108 	if (first_not_zeroed == ngroups ||
3109 	    (sb->s_flags & MS_RDONLY) ||
3110 	    !test_opt(sb, INIT_INODE_TABLE))
3111 		goto out;
3112 
3113 	elr = ext4_li_request_new(sb, first_not_zeroed);
3114 	if (!elr) {
3115 		ret = -ENOMEM;
3116 		goto out;
3117 	}
3118 
3119 	if (NULL == ext4_li_info) {
3120 		ret = ext4_li_info_new();
3121 		if (ret)
3122 			goto out;
3123 	}
3124 
3125 	mutex_lock(&ext4_li_info->li_list_mtx);
3126 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3127 	mutex_unlock(&ext4_li_info->li_list_mtx);
3128 
3129 	sbi->s_li_request = elr;
3130 	/*
3131 	 * set elr to NULL here since it has been inserted to
3132 	 * the request_list and the removal and free of it is
3133 	 * handled by ext4_clear_request_list from now on.
3134 	 */
3135 	elr = NULL;
3136 
3137 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3138 		ret = ext4_run_lazyinit_thread();
3139 		if (ret)
3140 			goto out;
3141 	}
3142 out:
3143 	mutex_unlock(&ext4_li_mtx);
3144 	if (ret)
3145 		kfree(elr);
3146 	return ret;
3147 }
3148 
3149 /*
3150  * We do not need to lock anything since this is called on
3151  * module unload.
3152  */
3153 static void ext4_destroy_lazyinit_thread(void)
3154 {
3155 	/*
3156 	 * If thread exited earlier
3157 	 * there's nothing to be done.
3158 	 */
3159 	if (!ext4_li_info || !ext4_lazyinit_task)
3160 		return;
3161 
3162 	kthread_stop(ext4_lazyinit_task);
3163 }
3164 
3165 static int set_journal_csum_feature_set(struct super_block *sb)
3166 {
3167 	int ret = 1;
3168 	int compat, incompat;
3169 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3170 
3171 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3172 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3173 		/* journal checksum v2 */
3174 		compat = 0;
3175 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3176 	} else {
3177 		/* journal checksum v1 */
3178 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3179 		incompat = 0;
3180 	}
3181 
3182 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3183 		ret = jbd2_journal_set_features(sbi->s_journal,
3184 				compat, 0,
3185 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3186 				incompat);
3187 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3188 		ret = jbd2_journal_set_features(sbi->s_journal,
3189 				compat, 0,
3190 				incompat);
3191 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3192 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3193 	} else {
3194 		jbd2_journal_clear_features(sbi->s_journal,
3195 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3196 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3197 				JBD2_FEATURE_INCOMPAT_CSUM_V2);
3198 	}
3199 
3200 	return ret;
3201 }
3202 
3203 /*
3204  * Note: calculating the overhead so we can be compatible with
3205  * historical BSD practice is quite difficult in the face of
3206  * clusters/bigalloc.  This is because multiple metadata blocks from
3207  * different block group can end up in the same allocation cluster.
3208  * Calculating the exact overhead in the face of clustered allocation
3209  * requires either O(all block bitmaps) in memory or O(number of block
3210  * groups**2) in time.  We will still calculate the superblock for
3211  * older file systems --- and if we come across with a bigalloc file
3212  * system with zero in s_overhead_clusters the estimate will be close to
3213  * correct especially for very large cluster sizes --- but for newer
3214  * file systems, it's better to calculate this figure once at mkfs
3215  * time, and store it in the superblock.  If the superblock value is
3216  * present (even for non-bigalloc file systems), we will use it.
3217  */
3218 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3219 			  char *buf)
3220 {
3221 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3222 	struct ext4_group_desc	*gdp;
3223 	ext4_fsblk_t		first_block, last_block, b;
3224 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3225 	int			s, j, count = 0;
3226 
3227 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3228 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3229 			sbi->s_itb_per_group + 2);
3230 
3231 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3232 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3233 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3234 	for (i = 0; i < ngroups; i++) {
3235 		gdp = ext4_get_group_desc(sb, i, NULL);
3236 		b = ext4_block_bitmap(sb, gdp);
3237 		if (b >= first_block && b <= last_block) {
3238 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3239 			count++;
3240 		}
3241 		b = ext4_inode_bitmap(sb, gdp);
3242 		if (b >= first_block && b <= last_block) {
3243 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3244 			count++;
3245 		}
3246 		b = ext4_inode_table(sb, gdp);
3247 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3248 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3249 				int c = EXT4_B2C(sbi, b - first_block);
3250 				ext4_set_bit(c, buf);
3251 				count++;
3252 			}
3253 		if (i != grp)
3254 			continue;
3255 		s = 0;
3256 		if (ext4_bg_has_super(sb, grp)) {
3257 			ext4_set_bit(s++, buf);
3258 			count++;
3259 		}
3260 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3261 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3262 			count++;
3263 		}
3264 	}
3265 	if (!count)
3266 		return 0;
3267 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3268 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3269 }
3270 
3271 /*
3272  * Compute the overhead and stash it in sbi->s_overhead
3273  */
3274 int ext4_calculate_overhead(struct super_block *sb)
3275 {
3276 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3277 	struct ext4_super_block *es = sbi->s_es;
3278 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3279 	ext4_fsblk_t overhead = 0;
3280 	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3281 
3282 	if (!buf)
3283 		return -ENOMEM;
3284 
3285 	/*
3286 	 * Compute the overhead (FS structures).  This is constant
3287 	 * for a given filesystem unless the number of block groups
3288 	 * changes so we cache the previous value until it does.
3289 	 */
3290 
3291 	/*
3292 	 * All of the blocks before first_data_block are overhead
3293 	 */
3294 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3295 
3296 	/*
3297 	 * Add the overhead found in each block group
3298 	 */
3299 	for (i = 0; i < ngroups; i++) {
3300 		int blks;
3301 
3302 		blks = count_overhead(sb, i, buf);
3303 		overhead += blks;
3304 		if (blks)
3305 			memset(buf, 0, PAGE_SIZE);
3306 		cond_resched();
3307 	}
3308 	/* Add the journal blocks as well */
3309 	if (sbi->s_journal)
3310 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3311 
3312 	sbi->s_overhead = overhead;
3313 	smp_wmb();
3314 	free_page((unsigned long) buf);
3315 	return 0;
3316 }
3317 
3318 
3319 static ext4_fsblk_t ext4_calculate_resv_clusters(struct ext4_sb_info *sbi)
3320 {
3321 	ext4_fsblk_t resv_clusters;
3322 
3323 	/*
3324 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3325 	 * This should cover the situations where we can not afford to run
3326 	 * out of space like for example punch hole, or converting
3327 	 * uninitialized extents in delalloc path. In most cases such
3328 	 * allocation would require 1, or 2 blocks, higher numbers are
3329 	 * very rare.
3330 	 */
3331 	resv_clusters = ext4_blocks_count(sbi->s_es) >> sbi->s_cluster_bits;
3332 
3333 	do_div(resv_clusters, 50);
3334 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3335 
3336 	return resv_clusters;
3337 }
3338 
3339 
3340 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3341 {
3342 	ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3343 				sbi->s_cluster_bits;
3344 
3345 	if (count >= clusters)
3346 		return -EINVAL;
3347 
3348 	atomic64_set(&sbi->s_resv_clusters, count);
3349 	return 0;
3350 }
3351 
3352 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3353 {
3354 	char *orig_data = kstrdup(data, GFP_KERNEL);
3355 	struct buffer_head *bh;
3356 	struct ext4_super_block *es = NULL;
3357 	struct ext4_sb_info *sbi;
3358 	ext4_fsblk_t block;
3359 	ext4_fsblk_t sb_block = get_sb_block(&data);
3360 	ext4_fsblk_t logical_sb_block;
3361 	unsigned long offset = 0;
3362 	unsigned long journal_devnum = 0;
3363 	unsigned long def_mount_opts;
3364 	struct inode *root;
3365 	char *cp;
3366 	const char *descr;
3367 	int ret = -ENOMEM;
3368 	int blocksize, clustersize;
3369 	unsigned int db_count;
3370 	unsigned int i;
3371 	int needs_recovery, has_huge_files, has_bigalloc;
3372 	__u64 blocks_count;
3373 	int err = 0;
3374 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3375 	ext4_group_t first_not_zeroed;
3376 
3377 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3378 	if (!sbi)
3379 		goto out_free_orig;
3380 
3381 	sbi->s_blockgroup_lock =
3382 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3383 	if (!sbi->s_blockgroup_lock) {
3384 		kfree(sbi);
3385 		goto out_free_orig;
3386 	}
3387 	sb->s_fs_info = sbi;
3388 	sbi->s_sb = sb;
3389 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3390 	sbi->s_sb_block = sb_block;
3391 	if (sb->s_bdev->bd_part)
3392 		sbi->s_sectors_written_start =
3393 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3394 
3395 	/* Cleanup superblock name */
3396 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3397 		*cp = '!';
3398 
3399 	/* -EINVAL is default */
3400 	ret = -EINVAL;
3401 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3402 	if (!blocksize) {
3403 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3404 		goto out_fail;
3405 	}
3406 
3407 	/*
3408 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3409 	 * block sizes.  We need to calculate the offset from buffer start.
3410 	 */
3411 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3412 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3413 		offset = do_div(logical_sb_block, blocksize);
3414 	} else {
3415 		logical_sb_block = sb_block;
3416 	}
3417 
3418 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3419 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3420 		goto out_fail;
3421 	}
3422 	/*
3423 	 * Note: s_es must be initialized as soon as possible because
3424 	 *       some ext4 macro-instructions depend on its value
3425 	 */
3426 	es = (struct ext4_super_block *) (bh->b_data + offset);
3427 	sbi->s_es = es;
3428 	sb->s_magic = le16_to_cpu(es->s_magic);
3429 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3430 		goto cantfind_ext4;
3431 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3432 
3433 	/* Warn if metadata_csum and gdt_csum are both set. */
3434 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3435 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3436 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3437 		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3438 			     "redundant flags; please run fsck.");
3439 
3440 	/* Check for a known checksum algorithm */
3441 	if (!ext4_verify_csum_type(sb, es)) {
3442 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3443 			 "unknown checksum algorithm.");
3444 		silent = 1;
3445 		goto cantfind_ext4;
3446 	}
3447 
3448 	/* Load the checksum driver */
3449 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3450 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3451 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3452 		if (IS_ERR(sbi->s_chksum_driver)) {
3453 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3454 			ret = PTR_ERR(sbi->s_chksum_driver);
3455 			sbi->s_chksum_driver = NULL;
3456 			goto failed_mount;
3457 		}
3458 	}
3459 
3460 	/* Check superblock checksum */
3461 	if (!ext4_superblock_csum_verify(sb, es)) {
3462 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3463 			 "invalid superblock checksum.  Run e2fsck?");
3464 		silent = 1;
3465 		goto cantfind_ext4;
3466 	}
3467 
3468 	/* Precompute checksum seed for all metadata */
3469 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3470 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3471 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3472 					       sizeof(es->s_uuid));
3473 
3474 	/* Set defaults before we parse the mount options */
3475 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3476 	set_opt(sb, INIT_INODE_TABLE);
3477 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3478 		set_opt(sb, DEBUG);
3479 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3480 		set_opt(sb, GRPID);
3481 	if (def_mount_opts & EXT4_DEFM_UID16)
3482 		set_opt(sb, NO_UID32);
3483 	/* xattr user namespace & acls are now defaulted on */
3484 	set_opt(sb, XATTR_USER);
3485 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3486 	set_opt(sb, POSIX_ACL);
3487 #endif
3488 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3489 		set_opt(sb, JOURNAL_DATA);
3490 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3491 		set_opt(sb, ORDERED_DATA);
3492 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3493 		set_opt(sb, WRITEBACK_DATA);
3494 
3495 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3496 		set_opt(sb, ERRORS_PANIC);
3497 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3498 		set_opt(sb, ERRORS_CONT);
3499 	else
3500 		set_opt(sb, ERRORS_RO);
3501 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3502 		set_opt(sb, BLOCK_VALIDITY);
3503 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3504 		set_opt(sb, DISCARD);
3505 
3506 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3507 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3508 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3509 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3510 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3511 
3512 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3513 		set_opt(sb, BARRIER);
3514 
3515 	/*
3516 	 * enable delayed allocation by default
3517 	 * Use -o nodelalloc to turn it off
3518 	 */
3519 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3520 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3521 		set_opt(sb, DELALLOC);
3522 
3523 	/*
3524 	 * set default s_li_wait_mult for lazyinit, for the case there is
3525 	 * no mount option specified.
3526 	 */
3527 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3528 
3529 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3530 			   &journal_devnum, &journal_ioprio, 0)) {
3531 		ext4_msg(sb, KERN_WARNING,
3532 			 "failed to parse options in superblock: %s",
3533 			 sbi->s_es->s_mount_opts);
3534 	}
3535 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3536 	if (!parse_options((char *) data, sb, &journal_devnum,
3537 			   &journal_ioprio, 0))
3538 		goto failed_mount;
3539 
3540 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3541 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3542 			    "with data=journal disables delayed "
3543 			    "allocation and O_DIRECT support!\n");
3544 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3545 			ext4_msg(sb, KERN_ERR, "can't mount with "
3546 				 "both data=journal and delalloc");
3547 			goto failed_mount;
3548 		}
3549 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3550 			ext4_msg(sb, KERN_ERR, "can't mount with "
3551 				 "both data=journal and dioread_nolock");
3552 			goto failed_mount;
3553 		}
3554 		if (test_opt(sb, DELALLOC))
3555 			clear_opt(sb, DELALLOC);
3556 	}
3557 
3558 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3559 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3560 
3561 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3562 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3563 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3564 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3565 		ext4_msg(sb, KERN_WARNING,
3566 		       "feature flags set on rev 0 fs, "
3567 		       "running e2fsck is recommended");
3568 
3569 	if (IS_EXT2_SB(sb)) {
3570 		if (ext2_feature_set_ok(sb))
3571 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3572 				 "using the ext4 subsystem");
3573 		else {
3574 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3575 				 "to feature incompatibilities");
3576 			goto failed_mount;
3577 		}
3578 	}
3579 
3580 	if (IS_EXT3_SB(sb)) {
3581 		if (ext3_feature_set_ok(sb))
3582 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3583 				 "using the ext4 subsystem");
3584 		else {
3585 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3586 				 "to feature incompatibilities");
3587 			goto failed_mount;
3588 		}
3589 	}
3590 
3591 	/*
3592 	 * Check feature flags regardless of the revision level, since we
3593 	 * previously didn't change the revision level when setting the flags,
3594 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3595 	 */
3596 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3597 		goto failed_mount;
3598 
3599 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3600 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3601 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3602 		ext4_msg(sb, KERN_ERR,
3603 		       "Unsupported filesystem blocksize %d", blocksize);
3604 		goto failed_mount;
3605 	}
3606 
3607 	if (sb->s_blocksize != blocksize) {
3608 		/* Validate the filesystem blocksize */
3609 		if (!sb_set_blocksize(sb, blocksize)) {
3610 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3611 					blocksize);
3612 			goto failed_mount;
3613 		}
3614 
3615 		brelse(bh);
3616 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3617 		offset = do_div(logical_sb_block, blocksize);
3618 		bh = sb_bread(sb, logical_sb_block);
3619 		if (!bh) {
3620 			ext4_msg(sb, KERN_ERR,
3621 			       "Can't read superblock on 2nd try");
3622 			goto failed_mount;
3623 		}
3624 		es = (struct ext4_super_block *)(bh->b_data + offset);
3625 		sbi->s_es = es;
3626 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3627 			ext4_msg(sb, KERN_ERR,
3628 			       "Magic mismatch, very weird!");
3629 			goto failed_mount;
3630 		}
3631 	}
3632 
3633 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3634 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3635 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3636 						      has_huge_files);
3637 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3638 
3639 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3640 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3641 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3642 	} else {
3643 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3644 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3645 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3646 		    (!is_power_of_2(sbi->s_inode_size)) ||
3647 		    (sbi->s_inode_size > blocksize)) {
3648 			ext4_msg(sb, KERN_ERR,
3649 			       "unsupported inode size: %d",
3650 			       sbi->s_inode_size);
3651 			goto failed_mount;
3652 		}
3653 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3654 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3655 	}
3656 
3657 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3658 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3659 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3660 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3661 		    !is_power_of_2(sbi->s_desc_size)) {
3662 			ext4_msg(sb, KERN_ERR,
3663 			       "unsupported descriptor size %lu",
3664 			       sbi->s_desc_size);
3665 			goto failed_mount;
3666 		}
3667 	} else
3668 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3669 
3670 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3671 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3672 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3673 		goto cantfind_ext4;
3674 
3675 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3676 	if (sbi->s_inodes_per_block == 0)
3677 		goto cantfind_ext4;
3678 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3679 					sbi->s_inodes_per_block;
3680 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3681 	sbi->s_sbh = bh;
3682 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3683 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3684 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3685 
3686 	for (i = 0; i < 4; i++)
3687 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3688 	sbi->s_def_hash_version = es->s_def_hash_version;
3689 	i = le32_to_cpu(es->s_flags);
3690 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3691 		sbi->s_hash_unsigned = 3;
3692 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3693 #ifdef __CHAR_UNSIGNED__
3694 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3695 		sbi->s_hash_unsigned = 3;
3696 #else
3697 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3698 #endif
3699 	}
3700 
3701 	/* Handle clustersize */
3702 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3703 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3704 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3705 	if (has_bigalloc) {
3706 		if (clustersize < blocksize) {
3707 			ext4_msg(sb, KERN_ERR,
3708 				 "cluster size (%d) smaller than "
3709 				 "block size (%d)", clustersize, blocksize);
3710 			goto failed_mount;
3711 		}
3712 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3713 			le32_to_cpu(es->s_log_block_size);
3714 		sbi->s_clusters_per_group =
3715 			le32_to_cpu(es->s_clusters_per_group);
3716 		if (sbi->s_clusters_per_group > blocksize * 8) {
3717 			ext4_msg(sb, KERN_ERR,
3718 				 "#clusters per group too big: %lu",
3719 				 sbi->s_clusters_per_group);
3720 			goto failed_mount;
3721 		}
3722 		if (sbi->s_blocks_per_group !=
3723 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3724 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3725 				 "clusters per group (%lu) inconsistent",
3726 				 sbi->s_blocks_per_group,
3727 				 sbi->s_clusters_per_group);
3728 			goto failed_mount;
3729 		}
3730 	} else {
3731 		if (clustersize != blocksize) {
3732 			ext4_warning(sb, "fragment/cluster size (%d) != "
3733 				     "block size (%d)", clustersize,
3734 				     blocksize);
3735 			clustersize = blocksize;
3736 		}
3737 		if (sbi->s_blocks_per_group > blocksize * 8) {
3738 			ext4_msg(sb, KERN_ERR,
3739 				 "#blocks per group too big: %lu",
3740 				 sbi->s_blocks_per_group);
3741 			goto failed_mount;
3742 		}
3743 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3744 		sbi->s_cluster_bits = 0;
3745 	}
3746 	sbi->s_cluster_ratio = clustersize / blocksize;
3747 
3748 	if (sbi->s_inodes_per_group > blocksize * 8) {
3749 		ext4_msg(sb, KERN_ERR,
3750 		       "#inodes per group too big: %lu",
3751 		       sbi->s_inodes_per_group);
3752 		goto failed_mount;
3753 	}
3754 
3755 	/* Do we have standard group size of clustersize * 8 blocks ? */
3756 	if (sbi->s_blocks_per_group == clustersize << 3)
3757 		set_opt2(sb, STD_GROUP_SIZE);
3758 
3759 	/*
3760 	 * Test whether we have more sectors than will fit in sector_t,
3761 	 * and whether the max offset is addressable by the page cache.
3762 	 */
3763 	err = generic_check_addressable(sb->s_blocksize_bits,
3764 					ext4_blocks_count(es));
3765 	if (err) {
3766 		ext4_msg(sb, KERN_ERR, "filesystem"
3767 			 " too large to mount safely on this system");
3768 		if (sizeof(sector_t) < 8)
3769 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3770 		goto failed_mount;
3771 	}
3772 
3773 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3774 		goto cantfind_ext4;
3775 
3776 	/* check blocks count against device size */
3777 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3778 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3779 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3780 		       "exceeds size of device (%llu blocks)",
3781 		       ext4_blocks_count(es), blocks_count);
3782 		goto failed_mount;
3783 	}
3784 
3785 	/*
3786 	 * It makes no sense for the first data block to be beyond the end
3787 	 * of the filesystem.
3788 	 */
3789 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3790 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3791 			 "block %u is beyond end of filesystem (%llu)",
3792 			 le32_to_cpu(es->s_first_data_block),
3793 			 ext4_blocks_count(es));
3794 		goto failed_mount;
3795 	}
3796 	blocks_count = (ext4_blocks_count(es) -
3797 			le32_to_cpu(es->s_first_data_block) +
3798 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3799 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3800 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3801 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3802 		       "(block count %llu, first data block %u, "
3803 		       "blocks per group %lu)", sbi->s_groups_count,
3804 		       ext4_blocks_count(es),
3805 		       le32_to_cpu(es->s_first_data_block),
3806 		       EXT4_BLOCKS_PER_GROUP(sb));
3807 		goto failed_mount;
3808 	}
3809 	sbi->s_groups_count = blocks_count;
3810 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3811 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3812 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3813 		   EXT4_DESC_PER_BLOCK(sb);
3814 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3815 					  sizeof(struct buffer_head *),
3816 					  GFP_KERNEL);
3817 	if (sbi->s_group_desc == NULL) {
3818 		ext4_msg(sb, KERN_ERR, "not enough memory");
3819 		ret = -ENOMEM;
3820 		goto failed_mount;
3821 	}
3822 
3823 	if (ext4_proc_root)
3824 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3825 
3826 	if (sbi->s_proc)
3827 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3828 				 &ext4_seq_options_fops, sb);
3829 
3830 	bgl_lock_init(sbi->s_blockgroup_lock);
3831 
3832 	for (i = 0; i < db_count; i++) {
3833 		block = descriptor_loc(sb, logical_sb_block, i);
3834 		sbi->s_group_desc[i] = sb_bread(sb, block);
3835 		if (!sbi->s_group_desc[i]) {
3836 			ext4_msg(sb, KERN_ERR,
3837 			       "can't read group descriptor %d", i);
3838 			db_count = i;
3839 			goto failed_mount2;
3840 		}
3841 	}
3842 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3843 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3844 		goto failed_mount2;
3845 	}
3846 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3847 		if (!ext4_fill_flex_info(sb)) {
3848 			ext4_msg(sb, KERN_ERR,
3849 			       "unable to initialize "
3850 			       "flex_bg meta info!");
3851 			goto failed_mount2;
3852 		}
3853 
3854 	sbi->s_gdb_count = db_count;
3855 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3856 	spin_lock_init(&sbi->s_next_gen_lock);
3857 
3858 	init_timer(&sbi->s_err_report);
3859 	sbi->s_err_report.function = print_daily_error_info;
3860 	sbi->s_err_report.data = (unsigned long) sb;
3861 
3862 	/* Register extent status tree shrinker */
3863 	ext4_es_register_shrinker(sbi);
3864 
3865 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3866 			ext4_count_free_clusters(sb));
3867 	if (!err) {
3868 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3869 				ext4_count_free_inodes(sb));
3870 	}
3871 	if (!err) {
3872 		err = percpu_counter_init(&sbi->s_dirs_counter,
3873 				ext4_count_dirs(sb));
3874 	}
3875 	if (!err) {
3876 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3877 	}
3878 	if (!err) {
3879 		err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3880 	}
3881 	if (err) {
3882 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3883 		goto failed_mount3;
3884 	}
3885 
3886 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3887 	sbi->s_extent_max_zeroout_kb = 32;
3888 
3889 	/*
3890 	 * set up enough so that it can read an inode
3891 	 */
3892 	if (!test_opt(sb, NOLOAD) &&
3893 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3894 		sb->s_op = &ext4_sops;
3895 	else
3896 		sb->s_op = &ext4_nojournal_sops;
3897 	sb->s_export_op = &ext4_export_ops;
3898 	sb->s_xattr = ext4_xattr_handlers;
3899 #ifdef CONFIG_QUOTA
3900 	sb->dq_op = &ext4_quota_operations;
3901 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3902 		sb->s_qcop = &ext4_qctl_sysfile_operations;
3903 	else
3904 		sb->s_qcop = &ext4_qctl_operations;
3905 #endif
3906 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3907 
3908 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3909 	mutex_init(&sbi->s_orphan_lock);
3910 
3911 	sb->s_root = NULL;
3912 
3913 	needs_recovery = (es->s_last_orphan != 0 ||
3914 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3915 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3916 
3917 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3918 	    !(sb->s_flags & MS_RDONLY))
3919 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3920 			goto failed_mount3;
3921 
3922 	/*
3923 	 * The first inode we look at is the journal inode.  Don't try
3924 	 * root first: it may be modified in the journal!
3925 	 */
3926 	if (!test_opt(sb, NOLOAD) &&
3927 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3928 		if (ext4_load_journal(sb, es, journal_devnum))
3929 			goto failed_mount3;
3930 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3931 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3932 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3933 		       "suppressed and not mounted read-only");
3934 		goto failed_mount_wq;
3935 	} else {
3936 		clear_opt(sb, DATA_FLAGS);
3937 		sbi->s_journal = NULL;
3938 		needs_recovery = 0;
3939 		goto no_journal;
3940 	}
3941 
3942 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3943 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3944 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3945 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3946 		goto failed_mount_wq;
3947 	}
3948 
3949 	if (!set_journal_csum_feature_set(sb)) {
3950 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3951 			 "feature set");
3952 		goto failed_mount_wq;
3953 	}
3954 
3955 	/* We have now updated the journal if required, so we can
3956 	 * validate the data journaling mode. */
3957 	switch (test_opt(sb, DATA_FLAGS)) {
3958 	case 0:
3959 		/* No mode set, assume a default based on the journal
3960 		 * capabilities: ORDERED_DATA if the journal can
3961 		 * cope, else JOURNAL_DATA
3962 		 */
3963 		if (jbd2_journal_check_available_features
3964 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3965 			set_opt(sb, ORDERED_DATA);
3966 		else
3967 			set_opt(sb, JOURNAL_DATA);
3968 		break;
3969 
3970 	case EXT4_MOUNT_ORDERED_DATA:
3971 	case EXT4_MOUNT_WRITEBACK_DATA:
3972 		if (!jbd2_journal_check_available_features
3973 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3974 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3975 			       "requested data journaling mode");
3976 			goto failed_mount_wq;
3977 		}
3978 	default:
3979 		break;
3980 	}
3981 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3982 
3983 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3984 
3985 	/*
3986 	 * The journal may have updated the bg summary counts, so we
3987 	 * need to update the global counters.
3988 	 */
3989 	percpu_counter_set(&sbi->s_freeclusters_counter,
3990 			   ext4_count_free_clusters(sb));
3991 	percpu_counter_set(&sbi->s_freeinodes_counter,
3992 			   ext4_count_free_inodes(sb));
3993 	percpu_counter_set(&sbi->s_dirs_counter,
3994 			   ext4_count_dirs(sb));
3995 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3996 
3997 no_journal:
3998 	/*
3999 	 * Get the # of file system overhead blocks from the
4000 	 * superblock if present.
4001 	 */
4002 	if (es->s_overhead_clusters)
4003 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4004 	else {
4005 		err = ext4_calculate_overhead(sb);
4006 		if (err)
4007 			goto failed_mount_wq;
4008 	}
4009 
4010 	/*
4011 	 * The maximum number of concurrent works can be high and
4012 	 * concurrency isn't really necessary.  Limit it to 1.
4013 	 */
4014 	EXT4_SB(sb)->rsv_conversion_wq =
4015 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4016 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4017 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4018 		ret = -ENOMEM;
4019 		goto failed_mount4;
4020 	}
4021 
4022 	/*
4023 	 * The jbd2_journal_load will have done any necessary log recovery,
4024 	 * so we can safely mount the rest of the filesystem now.
4025 	 */
4026 
4027 	root = ext4_iget(sb, EXT4_ROOT_INO);
4028 	if (IS_ERR(root)) {
4029 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4030 		ret = PTR_ERR(root);
4031 		root = NULL;
4032 		goto failed_mount4;
4033 	}
4034 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4035 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4036 		iput(root);
4037 		goto failed_mount4;
4038 	}
4039 	sb->s_root = d_make_root(root);
4040 	if (!sb->s_root) {
4041 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4042 		ret = -ENOMEM;
4043 		goto failed_mount4;
4044 	}
4045 
4046 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4047 		sb->s_flags |= MS_RDONLY;
4048 
4049 	/* determine the minimum size of new large inodes, if present */
4050 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4051 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4052 						     EXT4_GOOD_OLD_INODE_SIZE;
4053 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4054 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4055 			if (sbi->s_want_extra_isize <
4056 			    le16_to_cpu(es->s_want_extra_isize))
4057 				sbi->s_want_extra_isize =
4058 					le16_to_cpu(es->s_want_extra_isize);
4059 			if (sbi->s_want_extra_isize <
4060 			    le16_to_cpu(es->s_min_extra_isize))
4061 				sbi->s_want_extra_isize =
4062 					le16_to_cpu(es->s_min_extra_isize);
4063 		}
4064 	}
4065 	/* Check if enough inode space is available */
4066 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4067 							sbi->s_inode_size) {
4068 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4069 						       EXT4_GOOD_OLD_INODE_SIZE;
4070 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4071 			 "available");
4072 	}
4073 
4074 	err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sbi));
4075 	if (err) {
4076 		ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4077 			 "reserved pool", ext4_calculate_resv_clusters(sbi));
4078 		goto failed_mount4a;
4079 	}
4080 
4081 	err = ext4_setup_system_zone(sb);
4082 	if (err) {
4083 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4084 			 "zone (%d)", err);
4085 		goto failed_mount4a;
4086 	}
4087 
4088 	ext4_ext_init(sb);
4089 	err = ext4_mb_init(sb);
4090 	if (err) {
4091 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4092 			 err);
4093 		goto failed_mount5;
4094 	}
4095 
4096 	err = ext4_register_li_request(sb, first_not_zeroed);
4097 	if (err)
4098 		goto failed_mount6;
4099 
4100 	sbi->s_kobj.kset = ext4_kset;
4101 	init_completion(&sbi->s_kobj_unregister);
4102 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4103 				   "%s", sb->s_id);
4104 	if (err)
4105 		goto failed_mount7;
4106 
4107 #ifdef CONFIG_QUOTA
4108 	/* Enable quota usage during mount. */
4109 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4110 	    !(sb->s_flags & MS_RDONLY)) {
4111 		err = ext4_enable_quotas(sb);
4112 		if (err)
4113 			goto failed_mount8;
4114 	}
4115 #endif  /* CONFIG_QUOTA */
4116 
4117 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4118 	ext4_orphan_cleanup(sb, es);
4119 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4120 	if (needs_recovery) {
4121 		ext4_msg(sb, KERN_INFO, "recovery complete");
4122 		ext4_mark_recovery_complete(sb, es);
4123 	}
4124 	if (EXT4_SB(sb)->s_journal) {
4125 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4126 			descr = " journalled data mode";
4127 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4128 			descr = " ordered data mode";
4129 		else
4130 			descr = " writeback data mode";
4131 	} else
4132 		descr = "out journal";
4133 
4134 	if (test_opt(sb, DISCARD)) {
4135 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4136 		if (!blk_queue_discard(q))
4137 			ext4_msg(sb, KERN_WARNING,
4138 				 "mounting with \"discard\" option, but "
4139 				 "the device does not support discard");
4140 	}
4141 
4142 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4143 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4144 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4145 
4146 	if (es->s_error_count)
4147 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4148 
4149 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4150 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4151 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4152 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4153 
4154 	kfree(orig_data);
4155 	return 0;
4156 
4157 cantfind_ext4:
4158 	if (!silent)
4159 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4160 	goto failed_mount;
4161 
4162 #ifdef CONFIG_QUOTA
4163 failed_mount8:
4164 	kobject_del(&sbi->s_kobj);
4165 #endif
4166 failed_mount7:
4167 	ext4_unregister_li_request(sb);
4168 failed_mount6:
4169 	ext4_mb_release(sb);
4170 failed_mount5:
4171 	ext4_ext_release(sb);
4172 	ext4_release_system_zone(sb);
4173 failed_mount4a:
4174 	dput(sb->s_root);
4175 	sb->s_root = NULL;
4176 failed_mount4:
4177 	ext4_msg(sb, KERN_ERR, "mount failed");
4178 	if (EXT4_SB(sb)->rsv_conversion_wq)
4179 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4180 failed_mount_wq:
4181 	if (sbi->s_journal) {
4182 		jbd2_journal_destroy(sbi->s_journal);
4183 		sbi->s_journal = NULL;
4184 	}
4185 failed_mount3:
4186 	ext4_es_unregister_shrinker(sbi);
4187 	del_timer(&sbi->s_err_report);
4188 	if (sbi->s_flex_groups)
4189 		ext4_kvfree(sbi->s_flex_groups);
4190 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4191 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4192 	percpu_counter_destroy(&sbi->s_dirs_counter);
4193 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4194 	percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4195 	if (sbi->s_mmp_tsk)
4196 		kthread_stop(sbi->s_mmp_tsk);
4197 failed_mount2:
4198 	for (i = 0; i < db_count; i++)
4199 		brelse(sbi->s_group_desc[i]);
4200 	ext4_kvfree(sbi->s_group_desc);
4201 failed_mount:
4202 	if (sbi->s_chksum_driver)
4203 		crypto_free_shash(sbi->s_chksum_driver);
4204 	if (sbi->s_proc) {
4205 		remove_proc_entry("options", sbi->s_proc);
4206 		remove_proc_entry(sb->s_id, ext4_proc_root);
4207 	}
4208 #ifdef CONFIG_QUOTA
4209 	for (i = 0; i < MAXQUOTAS; i++)
4210 		kfree(sbi->s_qf_names[i]);
4211 #endif
4212 	ext4_blkdev_remove(sbi);
4213 	brelse(bh);
4214 out_fail:
4215 	sb->s_fs_info = NULL;
4216 	kfree(sbi->s_blockgroup_lock);
4217 	kfree(sbi);
4218 out_free_orig:
4219 	kfree(orig_data);
4220 	return err ? err : ret;
4221 }
4222 
4223 /*
4224  * Setup any per-fs journal parameters now.  We'll do this both on
4225  * initial mount, once the journal has been initialised but before we've
4226  * done any recovery; and again on any subsequent remount.
4227  */
4228 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4229 {
4230 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4231 
4232 	journal->j_commit_interval = sbi->s_commit_interval;
4233 	journal->j_min_batch_time = sbi->s_min_batch_time;
4234 	journal->j_max_batch_time = sbi->s_max_batch_time;
4235 
4236 	write_lock(&journal->j_state_lock);
4237 	if (test_opt(sb, BARRIER))
4238 		journal->j_flags |= JBD2_BARRIER;
4239 	else
4240 		journal->j_flags &= ~JBD2_BARRIER;
4241 	if (test_opt(sb, DATA_ERR_ABORT))
4242 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4243 	else
4244 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4245 	write_unlock(&journal->j_state_lock);
4246 }
4247 
4248 static journal_t *ext4_get_journal(struct super_block *sb,
4249 				   unsigned int journal_inum)
4250 {
4251 	struct inode *journal_inode;
4252 	journal_t *journal;
4253 
4254 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4255 
4256 	/* First, test for the existence of a valid inode on disk.  Bad
4257 	 * things happen if we iget() an unused inode, as the subsequent
4258 	 * iput() will try to delete it. */
4259 
4260 	journal_inode = ext4_iget(sb, journal_inum);
4261 	if (IS_ERR(journal_inode)) {
4262 		ext4_msg(sb, KERN_ERR, "no journal found");
4263 		return NULL;
4264 	}
4265 	if (!journal_inode->i_nlink) {
4266 		make_bad_inode(journal_inode);
4267 		iput(journal_inode);
4268 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4269 		return NULL;
4270 	}
4271 
4272 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4273 		  journal_inode, journal_inode->i_size);
4274 	if (!S_ISREG(journal_inode->i_mode)) {
4275 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4276 		iput(journal_inode);
4277 		return NULL;
4278 	}
4279 
4280 	journal = jbd2_journal_init_inode(journal_inode);
4281 	if (!journal) {
4282 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4283 		iput(journal_inode);
4284 		return NULL;
4285 	}
4286 	journal->j_private = sb;
4287 	ext4_init_journal_params(sb, journal);
4288 	return journal;
4289 }
4290 
4291 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4292 				       dev_t j_dev)
4293 {
4294 	struct buffer_head *bh;
4295 	journal_t *journal;
4296 	ext4_fsblk_t start;
4297 	ext4_fsblk_t len;
4298 	int hblock, blocksize;
4299 	ext4_fsblk_t sb_block;
4300 	unsigned long offset;
4301 	struct ext4_super_block *es;
4302 	struct block_device *bdev;
4303 
4304 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4305 
4306 	bdev = ext4_blkdev_get(j_dev, sb);
4307 	if (bdev == NULL)
4308 		return NULL;
4309 
4310 	blocksize = sb->s_blocksize;
4311 	hblock = bdev_logical_block_size(bdev);
4312 	if (blocksize < hblock) {
4313 		ext4_msg(sb, KERN_ERR,
4314 			"blocksize too small for journal device");
4315 		goto out_bdev;
4316 	}
4317 
4318 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4319 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4320 	set_blocksize(bdev, blocksize);
4321 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4322 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4323 		       "external journal");
4324 		goto out_bdev;
4325 	}
4326 
4327 	es = (struct ext4_super_block *) (bh->b_data + offset);
4328 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4329 	    !(le32_to_cpu(es->s_feature_incompat) &
4330 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4331 		ext4_msg(sb, KERN_ERR, "external journal has "
4332 					"bad superblock");
4333 		brelse(bh);
4334 		goto out_bdev;
4335 	}
4336 
4337 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4338 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4339 		brelse(bh);
4340 		goto out_bdev;
4341 	}
4342 
4343 	len = ext4_blocks_count(es);
4344 	start = sb_block + 1;
4345 	brelse(bh);	/* we're done with the superblock */
4346 
4347 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4348 					start, len, blocksize);
4349 	if (!journal) {
4350 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4351 		goto out_bdev;
4352 	}
4353 	journal->j_private = sb;
4354 	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4355 	wait_on_buffer(journal->j_sb_buffer);
4356 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4357 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4358 		goto out_journal;
4359 	}
4360 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4361 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4362 					"user (unsupported) - %d",
4363 			be32_to_cpu(journal->j_superblock->s_nr_users));
4364 		goto out_journal;
4365 	}
4366 	EXT4_SB(sb)->journal_bdev = bdev;
4367 	ext4_init_journal_params(sb, journal);
4368 	return journal;
4369 
4370 out_journal:
4371 	jbd2_journal_destroy(journal);
4372 out_bdev:
4373 	ext4_blkdev_put(bdev);
4374 	return NULL;
4375 }
4376 
4377 static int ext4_load_journal(struct super_block *sb,
4378 			     struct ext4_super_block *es,
4379 			     unsigned long journal_devnum)
4380 {
4381 	journal_t *journal;
4382 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4383 	dev_t journal_dev;
4384 	int err = 0;
4385 	int really_read_only;
4386 
4387 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4388 
4389 	if (journal_devnum &&
4390 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4391 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4392 			"numbers have changed");
4393 		journal_dev = new_decode_dev(journal_devnum);
4394 	} else
4395 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4396 
4397 	really_read_only = bdev_read_only(sb->s_bdev);
4398 
4399 	/*
4400 	 * Are we loading a blank journal or performing recovery after a
4401 	 * crash?  For recovery, we need to check in advance whether we
4402 	 * can get read-write access to the device.
4403 	 */
4404 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4405 		if (sb->s_flags & MS_RDONLY) {
4406 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4407 					"required on readonly filesystem");
4408 			if (really_read_only) {
4409 				ext4_msg(sb, KERN_ERR, "write access "
4410 					"unavailable, cannot proceed");
4411 				return -EROFS;
4412 			}
4413 			ext4_msg(sb, KERN_INFO, "write access will "
4414 			       "be enabled during recovery");
4415 		}
4416 	}
4417 
4418 	if (journal_inum && journal_dev) {
4419 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4420 		       "and inode journals!");
4421 		return -EINVAL;
4422 	}
4423 
4424 	if (journal_inum) {
4425 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4426 			return -EINVAL;
4427 	} else {
4428 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4429 			return -EINVAL;
4430 	}
4431 
4432 	if (!(journal->j_flags & JBD2_BARRIER))
4433 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4434 
4435 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4436 		err = jbd2_journal_wipe(journal, !really_read_only);
4437 	if (!err) {
4438 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4439 		if (save)
4440 			memcpy(save, ((char *) es) +
4441 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4442 		err = jbd2_journal_load(journal);
4443 		if (save)
4444 			memcpy(((char *) es) + EXT4_S_ERR_START,
4445 			       save, EXT4_S_ERR_LEN);
4446 		kfree(save);
4447 	}
4448 
4449 	if (err) {
4450 		ext4_msg(sb, KERN_ERR, "error loading journal");
4451 		jbd2_journal_destroy(journal);
4452 		return err;
4453 	}
4454 
4455 	EXT4_SB(sb)->s_journal = journal;
4456 	ext4_clear_journal_err(sb, es);
4457 
4458 	if (!really_read_only && journal_devnum &&
4459 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4460 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4461 
4462 		/* Make sure we flush the recovery flag to disk. */
4463 		ext4_commit_super(sb, 1);
4464 	}
4465 
4466 	return 0;
4467 }
4468 
4469 static int ext4_commit_super(struct super_block *sb, int sync)
4470 {
4471 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4472 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4473 	int error = 0;
4474 
4475 	if (!sbh || block_device_ejected(sb))
4476 		return error;
4477 	if (buffer_write_io_error(sbh)) {
4478 		/*
4479 		 * Oh, dear.  A previous attempt to write the
4480 		 * superblock failed.  This could happen because the
4481 		 * USB device was yanked out.  Or it could happen to
4482 		 * be a transient write error and maybe the block will
4483 		 * be remapped.  Nothing we can do but to retry the
4484 		 * write and hope for the best.
4485 		 */
4486 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4487 		       "superblock detected");
4488 		clear_buffer_write_io_error(sbh);
4489 		set_buffer_uptodate(sbh);
4490 	}
4491 	/*
4492 	 * If the file system is mounted read-only, don't update the
4493 	 * superblock write time.  This avoids updating the superblock
4494 	 * write time when we are mounting the root file system
4495 	 * read/only but we need to replay the journal; at that point,
4496 	 * for people who are east of GMT and who make their clock
4497 	 * tick in localtime for Windows bug-for-bug compatibility,
4498 	 * the clock is set in the future, and this will cause e2fsck
4499 	 * to complain and force a full file system check.
4500 	 */
4501 	if (!(sb->s_flags & MS_RDONLY))
4502 		es->s_wtime = cpu_to_le32(get_seconds());
4503 	if (sb->s_bdev->bd_part)
4504 		es->s_kbytes_written =
4505 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4506 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4507 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4508 	else
4509 		es->s_kbytes_written =
4510 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4511 	ext4_free_blocks_count_set(es,
4512 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4513 				&EXT4_SB(sb)->s_freeclusters_counter)));
4514 	es->s_free_inodes_count =
4515 		cpu_to_le32(percpu_counter_sum_positive(
4516 				&EXT4_SB(sb)->s_freeinodes_counter));
4517 	BUFFER_TRACE(sbh, "marking dirty");
4518 	ext4_superblock_csum_set(sb);
4519 	mark_buffer_dirty(sbh);
4520 	if (sync) {
4521 		error = sync_dirty_buffer(sbh);
4522 		if (error)
4523 			return error;
4524 
4525 		error = buffer_write_io_error(sbh);
4526 		if (error) {
4527 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4528 			       "superblock");
4529 			clear_buffer_write_io_error(sbh);
4530 			set_buffer_uptodate(sbh);
4531 		}
4532 	}
4533 	return error;
4534 }
4535 
4536 /*
4537  * Have we just finished recovery?  If so, and if we are mounting (or
4538  * remounting) the filesystem readonly, then we will end up with a
4539  * consistent fs on disk.  Record that fact.
4540  */
4541 static void ext4_mark_recovery_complete(struct super_block *sb,
4542 					struct ext4_super_block *es)
4543 {
4544 	journal_t *journal = EXT4_SB(sb)->s_journal;
4545 
4546 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4547 		BUG_ON(journal != NULL);
4548 		return;
4549 	}
4550 	jbd2_journal_lock_updates(journal);
4551 	if (jbd2_journal_flush(journal) < 0)
4552 		goto out;
4553 
4554 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4555 	    sb->s_flags & MS_RDONLY) {
4556 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4557 		ext4_commit_super(sb, 1);
4558 	}
4559 
4560 out:
4561 	jbd2_journal_unlock_updates(journal);
4562 }
4563 
4564 /*
4565  * If we are mounting (or read-write remounting) a filesystem whose journal
4566  * has recorded an error from a previous lifetime, move that error to the
4567  * main filesystem now.
4568  */
4569 static void ext4_clear_journal_err(struct super_block *sb,
4570 				   struct ext4_super_block *es)
4571 {
4572 	journal_t *journal;
4573 	int j_errno;
4574 	const char *errstr;
4575 
4576 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4577 
4578 	journal = EXT4_SB(sb)->s_journal;
4579 
4580 	/*
4581 	 * Now check for any error status which may have been recorded in the
4582 	 * journal by a prior ext4_error() or ext4_abort()
4583 	 */
4584 
4585 	j_errno = jbd2_journal_errno(journal);
4586 	if (j_errno) {
4587 		char nbuf[16];
4588 
4589 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4590 		ext4_warning(sb, "Filesystem error recorded "
4591 			     "from previous mount: %s", errstr);
4592 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4593 
4594 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4595 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4596 		ext4_commit_super(sb, 1);
4597 
4598 		jbd2_journal_clear_err(journal);
4599 		jbd2_journal_update_sb_errno(journal);
4600 	}
4601 }
4602 
4603 /*
4604  * Force the running and committing transactions to commit,
4605  * and wait on the commit.
4606  */
4607 int ext4_force_commit(struct super_block *sb)
4608 {
4609 	journal_t *journal;
4610 
4611 	if (sb->s_flags & MS_RDONLY)
4612 		return 0;
4613 
4614 	journal = EXT4_SB(sb)->s_journal;
4615 	return ext4_journal_force_commit(journal);
4616 }
4617 
4618 static int ext4_sync_fs(struct super_block *sb, int wait)
4619 {
4620 	int ret = 0;
4621 	tid_t target;
4622 	bool needs_barrier = false;
4623 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4624 
4625 	trace_ext4_sync_fs(sb, wait);
4626 	flush_workqueue(sbi->rsv_conversion_wq);
4627 	/*
4628 	 * Writeback quota in non-journalled quota case - journalled quota has
4629 	 * no dirty dquots
4630 	 */
4631 	dquot_writeback_dquots(sb, -1);
4632 	/*
4633 	 * Data writeback is possible w/o journal transaction, so barrier must
4634 	 * being sent at the end of the function. But we can skip it if
4635 	 * transaction_commit will do it for us.
4636 	 */
4637 	target = jbd2_get_latest_transaction(sbi->s_journal);
4638 	if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4639 	    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4640 		needs_barrier = true;
4641 
4642 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4643 		if (wait)
4644 			ret = jbd2_log_wait_commit(sbi->s_journal, target);
4645 	}
4646 	if (needs_barrier) {
4647 		int err;
4648 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4649 		if (!ret)
4650 			ret = err;
4651 	}
4652 
4653 	return ret;
4654 }
4655 
4656 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4657 {
4658 	int ret = 0;
4659 
4660 	trace_ext4_sync_fs(sb, wait);
4661 	flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4662 	dquot_writeback_dquots(sb, -1);
4663 	if (wait && test_opt(sb, BARRIER))
4664 		ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4665 
4666 	return ret;
4667 }
4668 
4669 /*
4670  * LVM calls this function before a (read-only) snapshot is created.  This
4671  * gives us a chance to flush the journal completely and mark the fs clean.
4672  *
4673  * Note that only this function cannot bring a filesystem to be in a clean
4674  * state independently. It relies on upper layer to stop all data & metadata
4675  * modifications.
4676  */
4677 static int ext4_freeze(struct super_block *sb)
4678 {
4679 	int error = 0;
4680 	journal_t *journal;
4681 
4682 	if (sb->s_flags & MS_RDONLY)
4683 		return 0;
4684 
4685 	journal = EXT4_SB(sb)->s_journal;
4686 
4687 	/* Now we set up the journal barrier. */
4688 	jbd2_journal_lock_updates(journal);
4689 
4690 	/*
4691 	 * Don't clear the needs_recovery flag if we failed to flush
4692 	 * the journal.
4693 	 */
4694 	error = jbd2_journal_flush(journal);
4695 	if (error < 0)
4696 		goto out;
4697 
4698 	/* Journal blocked and flushed, clear needs_recovery flag. */
4699 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4700 	error = ext4_commit_super(sb, 1);
4701 out:
4702 	/* we rely on upper layer to stop further updates */
4703 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4704 	return error;
4705 }
4706 
4707 /*
4708  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4709  * flag here, even though the filesystem is not technically dirty yet.
4710  */
4711 static int ext4_unfreeze(struct super_block *sb)
4712 {
4713 	if (sb->s_flags & MS_RDONLY)
4714 		return 0;
4715 
4716 	/* Reset the needs_recovery flag before the fs is unlocked. */
4717 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4718 	ext4_commit_super(sb, 1);
4719 	return 0;
4720 }
4721 
4722 /*
4723  * Structure to save mount options for ext4_remount's benefit
4724  */
4725 struct ext4_mount_options {
4726 	unsigned long s_mount_opt;
4727 	unsigned long s_mount_opt2;
4728 	kuid_t s_resuid;
4729 	kgid_t s_resgid;
4730 	unsigned long s_commit_interval;
4731 	u32 s_min_batch_time, s_max_batch_time;
4732 #ifdef CONFIG_QUOTA
4733 	int s_jquota_fmt;
4734 	char *s_qf_names[MAXQUOTAS];
4735 #endif
4736 };
4737 
4738 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4739 {
4740 	struct ext4_super_block *es;
4741 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4742 	unsigned long old_sb_flags;
4743 	struct ext4_mount_options old_opts;
4744 	int enable_quota = 0;
4745 	ext4_group_t g;
4746 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4747 	int err = 0;
4748 #ifdef CONFIG_QUOTA
4749 	int i, j;
4750 #endif
4751 	char *orig_data = kstrdup(data, GFP_KERNEL);
4752 
4753 	/* Store the original options */
4754 	old_sb_flags = sb->s_flags;
4755 	old_opts.s_mount_opt = sbi->s_mount_opt;
4756 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4757 	old_opts.s_resuid = sbi->s_resuid;
4758 	old_opts.s_resgid = sbi->s_resgid;
4759 	old_opts.s_commit_interval = sbi->s_commit_interval;
4760 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4761 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4762 #ifdef CONFIG_QUOTA
4763 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4764 	for (i = 0; i < MAXQUOTAS; i++)
4765 		if (sbi->s_qf_names[i]) {
4766 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4767 							 GFP_KERNEL);
4768 			if (!old_opts.s_qf_names[i]) {
4769 				for (j = 0; j < i; j++)
4770 					kfree(old_opts.s_qf_names[j]);
4771 				kfree(orig_data);
4772 				return -ENOMEM;
4773 			}
4774 		} else
4775 			old_opts.s_qf_names[i] = NULL;
4776 #endif
4777 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4778 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4779 
4780 	/*
4781 	 * Allow the "check" option to be passed as a remount option.
4782 	 */
4783 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4784 		err = -EINVAL;
4785 		goto restore_opts;
4786 	}
4787 
4788 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4789 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4790 			ext4_msg(sb, KERN_ERR, "can't mount with "
4791 				 "both data=journal and delalloc");
4792 			err = -EINVAL;
4793 			goto restore_opts;
4794 		}
4795 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4796 			ext4_msg(sb, KERN_ERR, "can't mount with "
4797 				 "both data=journal and dioread_nolock");
4798 			err = -EINVAL;
4799 			goto restore_opts;
4800 		}
4801 	}
4802 
4803 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4804 		ext4_abort(sb, "Abort forced by user");
4805 
4806 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4807 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4808 
4809 	es = sbi->s_es;
4810 
4811 	if (sbi->s_journal) {
4812 		ext4_init_journal_params(sb, sbi->s_journal);
4813 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4814 	}
4815 
4816 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4817 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4818 			err = -EROFS;
4819 			goto restore_opts;
4820 		}
4821 
4822 		if (*flags & MS_RDONLY) {
4823 			err = dquot_suspend(sb, -1);
4824 			if (err < 0)
4825 				goto restore_opts;
4826 
4827 			/*
4828 			 * First of all, the unconditional stuff we have to do
4829 			 * to disable replay of the journal when we next remount
4830 			 */
4831 			sb->s_flags |= MS_RDONLY;
4832 
4833 			/*
4834 			 * OK, test if we are remounting a valid rw partition
4835 			 * readonly, and if so set the rdonly flag and then
4836 			 * mark the partition as valid again.
4837 			 */
4838 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4839 			    (sbi->s_mount_state & EXT4_VALID_FS))
4840 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4841 
4842 			if (sbi->s_journal)
4843 				ext4_mark_recovery_complete(sb, es);
4844 		} else {
4845 			/* Make sure we can mount this feature set readwrite */
4846 			if (!ext4_feature_set_ok(sb, 0)) {
4847 				err = -EROFS;
4848 				goto restore_opts;
4849 			}
4850 			/*
4851 			 * Make sure the group descriptor checksums
4852 			 * are sane.  If they aren't, refuse to remount r/w.
4853 			 */
4854 			for (g = 0; g < sbi->s_groups_count; g++) {
4855 				struct ext4_group_desc *gdp =
4856 					ext4_get_group_desc(sb, g, NULL);
4857 
4858 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4859 					ext4_msg(sb, KERN_ERR,
4860 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4861 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4862 					       le16_to_cpu(gdp->bg_checksum));
4863 					err = -EINVAL;
4864 					goto restore_opts;
4865 				}
4866 			}
4867 
4868 			/*
4869 			 * If we have an unprocessed orphan list hanging
4870 			 * around from a previously readonly bdev mount,
4871 			 * require a full umount/remount for now.
4872 			 */
4873 			if (es->s_last_orphan) {
4874 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4875 				       "remount RDWR because of unprocessed "
4876 				       "orphan inode list.  Please "
4877 				       "umount/remount instead");
4878 				err = -EINVAL;
4879 				goto restore_opts;
4880 			}
4881 
4882 			/*
4883 			 * Mounting a RDONLY partition read-write, so reread
4884 			 * and store the current valid flag.  (It may have
4885 			 * been changed by e2fsck since we originally mounted
4886 			 * the partition.)
4887 			 */
4888 			if (sbi->s_journal)
4889 				ext4_clear_journal_err(sb, es);
4890 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4891 			if (!ext4_setup_super(sb, es, 0))
4892 				sb->s_flags &= ~MS_RDONLY;
4893 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4894 						     EXT4_FEATURE_INCOMPAT_MMP))
4895 				if (ext4_multi_mount_protect(sb,
4896 						le64_to_cpu(es->s_mmp_block))) {
4897 					err = -EROFS;
4898 					goto restore_opts;
4899 				}
4900 			enable_quota = 1;
4901 		}
4902 	}
4903 
4904 	/*
4905 	 * Reinitialize lazy itable initialization thread based on
4906 	 * current settings
4907 	 */
4908 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4909 		ext4_unregister_li_request(sb);
4910 	else {
4911 		ext4_group_t first_not_zeroed;
4912 		first_not_zeroed = ext4_has_uninit_itable(sb);
4913 		ext4_register_li_request(sb, first_not_zeroed);
4914 	}
4915 
4916 	ext4_setup_system_zone(sb);
4917 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4918 		ext4_commit_super(sb, 1);
4919 
4920 #ifdef CONFIG_QUOTA
4921 	/* Release old quota file names */
4922 	for (i = 0; i < MAXQUOTAS; i++)
4923 		kfree(old_opts.s_qf_names[i]);
4924 	if (enable_quota) {
4925 		if (sb_any_quota_suspended(sb))
4926 			dquot_resume(sb, -1);
4927 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4928 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4929 			err = ext4_enable_quotas(sb);
4930 			if (err)
4931 				goto restore_opts;
4932 		}
4933 	}
4934 #endif
4935 
4936 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4937 	kfree(orig_data);
4938 	return 0;
4939 
4940 restore_opts:
4941 	sb->s_flags = old_sb_flags;
4942 	sbi->s_mount_opt = old_opts.s_mount_opt;
4943 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4944 	sbi->s_resuid = old_opts.s_resuid;
4945 	sbi->s_resgid = old_opts.s_resgid;
4946 	sbi->s_commit_interval = old_opts.s_commit_interval;
4947 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4948 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4949 #ifdef CONFIG_QUOTA
4950 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4951 	for (i = 0; i < MAXQUOTAS; i++) {
4952 		kfree(sbi->s_qf_names[i]);
4953 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4954 	}
4955 #endif
4956 	kfree(orig_data);
4957 	return err;
4958 }
4959 
4960 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4961 {
4962 	struct super_block *sb = dentry->d_sb;
4963 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4964 	struct ext4_super_block *es = sbi->s_es;
4965 	ext4_fsblk_t overhead = 0, resv_blocks;
4966 	u64 fsid;
4967 	s64 bfree;
4968 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4969 
4970 	if (!test_opt(sb, MINIX_DF))
4971 		overhead = sbi->s_overhead;
4972 
4973 	buf->f_type = EXT4_SUPER_MAGIC;
4974 	buf->f_bsize = sb->s_blocksize;
4975 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4976 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4977 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4978 	/* prevent underflow in case that few free space is available */
4979 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4980 	buf->f_bavail = buf->f_bfree -
4981 			(ext4_r_blocks_count(es) + resv_blocks);
4982 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4983 		buf->f_bavail = 0;
4984 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4985 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4986 	buf->f_namelen = EXT4_NAME_LEN;
4987 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4988 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4989 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4990 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4991 
4992 	return 0;
4993 }
4994 
4995 /* Helper function for writing quotas on sync - we need to start transaction
4996  * before quota file is locked for write. Otherwise the are possible deadlocks:
4997  * Process 1                         Process 2
4998  * ext4_create()                     quota_sync()
4999  *   jbd2_journal_start()                  write_dquot()
5000  *   dquot_initialize()                         down(dqio_mutex)
5001  *     down(dqio_mutex)                    jbd2_journal_start()
5002  *
5003  */
5004 
5005 #ifdef CONFIG_QUOTA
5006 
5007 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5008 {
5009 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5010 }
5011 
5012 static int ext4_write_dquot(struct dquot *dquot)
5013 {
5014 	int ret, err;
5015 	handle_t *handle;
5016 	struct inode *inode;
5017 
5018 	inode = dquot_to_inode(dquot);
5019 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5020 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5021 	if (IS_ERR(handle))
5022 		return PTR_ERR(handle);
5023 	ret = dquot_commit(dquot);
5024 	err = ext4_journal_stop(handle);
5025 	if (!ret)
5026 		ret = err;
5027 	return ret;
5028 }
5029 
5030 static int ext4_acquire_dquot(struct dquot *dquot)
5031 {
5032 	int ret, err;
5033 	handle_t *handle;
5034 
5035 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5036 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5037 	if (IS_ERR(handle))
5038 		return PTR_ERR(handle);
5039 	ret = dquot_acquire(dquot);
5040 	err = ext4_journal_stop(handle);
5041 	if (!ret)
5042 		ret = err;
5043 	return ret;
5044 }
5045 
5046 static int ext4_release_dquot(struct dquot *dquot)
5047 {
5048 	int ret, err;
5049 	handle_t *handle;
5050 
5051 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5052 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5053 	if (IS_ERR(handle)) {
5054 		/* Release dquot anyway to avoid endless cycle in dqput() */
5055 		dquot_release(dquot);
5056 		return PTR_ERR(handle);
5057 	}
5058 	ret = dquot_release(dquot);
5059 	err = ext4_journal_stop(handle);
5060 	if (!ret)
5061 		ret = err;
5062 	return ret;
5063 }
5064 
5065 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5066 {
5067 	struct super_block *sb = dquot->dq_sb;
5068 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5069 
5070 	/* Are we journaling quotas? */
5071 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5072 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5073 		dquot_mark_dquot_dirty(dquot);
5074 		return ext4_write_dquot(dquot);
5075 	} else {
5076 		return dquot_mark_dquot_dirty(dquot);
5077 	}
5078 }
5079 
5080 static int ext4_write_info(struct super_block *sb, int type)
5081 {
5082 	int ret, err;
5083 	handle_t *handle;
5084 
5085 	/* Data block + inode block */
5086 	handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5087 	if (IS_ERR(handle))
5088 		return PTR_ERR(handle);
5089 	ret = dquot_commit_info(sb, type);
5090 	err = ext4_journal_stop(handle);
5091 	if (!ret)
5092 		ret = err;
5093 	return ret;
5094 }
5095 
5096 /*
5097  * Turn on quotas during mount time - we need to find
5098  * the quota file and such...
5099  */
5100 static int ext4_quota_on_mount(struct super_block *sb, int type)
5101 {
5102 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5103 					EXT4_SB(sb)->s_jquota_fmt, type);
5104 }
5105 
5106 /*
5107  * Standard function to be called on quota_on
5108  */
5109 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5110 			 struct path *path)
5111 {
5112 	int err;
5113 
5114 	if (!test_opt(sb, QUOTA))
5115 		return -EINVAL;
5116 
5117 	/* Quotafile not on the same filesystem? */
5118 	if (path->dentry->d_sb != sb)
5119 		return -EXDEV;
5120 	/* Journaling quota? */
5121 	if (EXT4_SB(sb)->s_qf_names[type]) {
5122 		/* Quotafile not in fs root? */
5123 		if (path->dentry->d_parent != sb->s_root)
5124 			ext4_msg(sb, KERN_WARNING,
5125 				"Quota file not on filesystem root. "
5126 				"Journaled quota will not work");
5127 	}
5128 
5129 	/*
5130 	 * When we journal data on quota file, we have to flush journal to see
5131 	 * all updates to the file when we bypass pagecache...
5132 	 */
5133 	if (EXT4_SB(sb)->s_journal &&
5134 	    ext4_should_journal_data(path->dentry->d_inode)) {
5135 		/*
5136 		 * We don't need to lock updates but journal_flush() could
5137 		 * otherwise be livelocked...
5138 		 */
5139 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5140 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5141 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5142 		if (err)
5143 			return err;
5144 	}
5145 
5146 	return dquot_quota_on(sb, type, format_id, path);
5147 }
5148 
5149 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5150 			     unsigned int flags)
5151 {
5152 	int err;
5153 	struct inode *qf_inode;
5154 	unsigned long qf_inums[MAXQUOTAS] = {
5155 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5156 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5157 	};
5158 
5159 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5160 
5161 	if (!qf_inums[type])
5162 		return -EPERM;
5163 
5164 	qf_inode = ext4_iget(sb, qf_inums[type]);
5165 	if (IS_ERR(qf_inode)) {
5166 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5167 		return PTR_ERR(qf_inode);
5168 	}
5169 
5170 	/* Don't account quota for quota files to avoid recursion */
5171 	qf_inode->i_flags |= S_NOQUOTA;
5172 	err = dquot_enable(qf_inode, type, format_id, flags);
5173 	iput(qf_inode);
5174 
5175 	return err;
5176 }
5177 
5178 /* Enable usage tracking for all quota types. */
5179 static int ext4_enable_quotas(struct super_block *sb)
5180 {
5181 	int type, err = 0;
5182 	unsigned long qf_inums[MAXQUOTAS] = {
5183 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5184 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5185 	};
5186 
5187 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5188 	for (type = 0; type < MAXQUOTAS; type++) {
5189 		if (qf_inums[type]) {
5190 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5191 						DQUOT_USAGE_ENABLED);
5192 			if (err) {
5193 				ext4_warning(sb,
5194 					"Failed to enable quota tracking "
5195 					"(type=%d, err=%d). Please run "
5196 					"e2fsck to fix.", type, err);
5197 				return err;
5198 			}
5199 		}
5200 	}
5201 	return 0;
5202 }
5203 
5204 /*
5205  * quota_on function that is used when QUOTA feature is set.
5206  */
5207 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5208 				 int format_id)
5209 {
5210 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5211 		return -EINVAL;
5212 
5213 	/*
5214 	 * USAGE was enabled at mount time. Only need to enable LIMITS now.
5215 	 */
5216 	return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5217 }
5218 
5219 static int ext4_quota_off(struct super_block *sb, int type)
5220 {
5221 	struct inode *inode = sb_dqopt(sb)->files[type];
5222 	handle_t *handle;
5223 
5224 	/* Force all delayed allocation blocks to be allocated.
5225 	 * Caller already holds s_umount sem */
5226 	if (test_opt(sb, DELALLOC))
5227 		sync_filesystem(sb);
5228 
5229 	if (!inode)
5230 		goto out;
5231 
5232 	/* Update modification times of quota files when userspace can
5233 	 * start looking at them */
5234 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5235 	if (IS_ERR(handle))
5236 		goto out;
5237 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5238 	ext4_mark_inode_dirty(handle, inode);
5239 	ext4_journal_stop(handle);
5240 
5241 out:
5242 	return dquot_quota_off(sb, type);
5243 }
5244 
5245 /*
5246  * quota_off function that is used when QUOTA feature is set.
5247  */
5248 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5249 {
5250 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5251 		return -EINVAL;
5252 
5253 	/* Disable only the limits. */
5254 	return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5255 }
5256 
5257 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5258  * acquiring the locks... As quota files are never truncated and quota code
5259  * itself serializes the operations (and no one else should touch the files)
5260  * we don't have to be afraid of races */
5261 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5262 			       size_t len, loff_t off)
5263 {
5264 	struct inode *inode = sb_dqopt(sb)->files[type];
5265 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5266 	int err = 0;
5267 	int offset = off & (sb->s_blocksize - 1);
5268 	int tocopy;
5269 	size_t toread;
5270 	struct buffer_head *bh;
5271 	loff_t i_size = i_size_read(inode);
5272 
5273 	if (off > i_size)
5274 		return 0;
5275 	if (off+len > i_size)
5276 		len = i_size-off;
5277 	toread = len;
5278 	while (toread > 0) {
5279 		tocopy = sb->s_blocksize - offset < toread ?
5280 				sb->s_blocksize - offset : toread;
5281 		bh = ext4_bread(NULL, inode, blk, 0, &err);
5282 		if (err)
5283 			return err;
5284 		if (!bh)	/* A hole? */
5285 			memset(data, 0, tocopy);
5286 		else
5287 			memcpy(data, bh->b_data+offset, tocopy);
5288 		brelse(bh);
5289 		offset = 0;
5290 		toread -= tocopy;
5291 		data += tocopy;
5292 		blk++;
5293 	}
5294 	return len;
5295 }
5296 
5297 /* Write to quotafile (we know the transaction is already started and has
5298  * enough credits) */
5299 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5300 				const char *data, size_t len, loff_t off)
5301 {
5302 	struct inode *inode = sb_dqopt(sb)->files[type];
5303 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5304 	int err = 0;
5305 	int offset = off & (sb->s_blocksize - 1);
5306 	struct buffer_head *bh;
5307 	handle_t *handle = journal_current_handle();
5308 
5309 	if (EXT4_SB(sb)->s_journal && !handle) {
5310 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5311 			" cancelled because transaction is not started",
5312 			(unsigned long long)off, (unsigned long long)len);
5313 		return -EIO;
5314 	}
5315 	/*
5316 	 * Since we account only one data block in transaction credits,
5317 	 * then it is impossible to cross a block boundary.
5318 	 */
5319 	if (sb->s_blocksize - offset < len) {
5320 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5321 			" cancelled because not block aligned",
5322 			(unsigned long long)off, (unsigned long long)len);
5323 		return -EIO;
5324 	}
5325 
5326 	bh = ext4_bread(handle, inode, blk, 1, &err);
5327 	if (!bh)
5328 		goto out;
5329 	err = ext4_journal_get_write_access(handle, bh);
5330 	if (err) {
5331 		brelse(bh);
5332 		goto out;
5333 	}
5334 	lock_buffer(bh);
5335 	memcpy(bh->b_data+offset, data, len);
5336 	flush_dcache_page(bh->b_page);
5337 	unlock_buffer(bh);
5338 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5339 	brelse(bh);
5340 out:
5341 	if (err)
5342 		return err;
5343 	if (inode->i_size < off + len) {
5344 		i_size_write(inode, off + len);
5345 		EXT4_I(inode)->i_disksize = inode->i_size;
5346 		ext4_mark_inode_dirty(handle, inode);
5347 	}
5348 	return len;
5349 }
5350 
5351 #endif
5352 
5353 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5354 		       const char *dev_name, void *data)
5355 {
5356 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5357 }
5358 
5359 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5360 static inline void register_as_ext2(void)
5361 {
5362 	int err = register_filesystem(&ext2_fs_type);
5363 	if (err)
5364 		printk(KERN_WARNING
5365 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5366 }
5367 
5368 static inline void unregister_as_ext2(void)
5369 {
5370 	unregister_filesystem(&ext2_fs_type);
5371 }
5372 
5373 static inline int ext2_feature_set_ok(struct super_block *sb)
5374 {
5375 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5376 		return 0;
5377 	if (sb->s_flags & MS_RDONLY)
5378 		return 1;
5379 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5380 		return 0;
5381 	return 1;
5382 }
5383 #else
5384 static inline void register_as_ext2(void) { }
5385 static inline void unregister_as_ext2(void) { }
5386 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5387 #endif
5388 
5389 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5390 static inline void register_as_ext3(void)
5391 {
5392 	int err = register_filesystem(&ext3_fs_type);
5393 	if (err)
5394 		printk(KERN_WARNING
5395 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5396 }
5397 
5398 static inline void unregister_as_ext3(void)
5399 {
5400 	unregister_filesystem(&ext3_fs_type);
5401 }
5402 
5403 static inline int ext3_feature_set_ok(struct super_block *sb)
5404 {
5405 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5406 		return 0;
5407 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5408 		return 0;
5409 	if (sb->s_flags & MS_RDONLY)
5410 		return 1;
5411 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5412 		return 0;
5413 	return 1;
5414 }
5415 #else
5416 static inline void register_as_ext3(void) { }
5417 static inline void unregister_as_ext3(void) { }
5418 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5419 #endif
5420 
5421 static struct file_system_type ext4_fs_type = {
5422 	.owner		= THIS_MODULE,
5423 	.name		= "ext4",
5424 	.mount		= ext4_mount,
5425 	.kill_sb	= kill_block_super,
5426 	.fs_flags	= FS_REQUIRES_DEV,
5427 };
5428 MODULE_ALIAS_FS("ext4");
5429 
5430 static int __init ext4_init_feat_adverts(void)
5431 {
5432 	struct ext4_features *ef;
5433 	int ret = -ENOMEM;
5434 
5435 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5436 	if (!ef)
5437 		goto out;
5438 
5439 	ef->f_kobj.kset = ext4_kset;
5440 	init_completion(&ef->f_kobj_unregister);
5441 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5442 				   "features");
5443 	if (ret) {
5444 		kfree(ef);
5445 		goto out;
5446 	}
5447 
5448 	ext4_feat = ef;
5449 	ret = 0;
5450 out:
5451 	return ret;
5452 }
5453 
5454 static void ext4_exit_feat_adverts(void)
5455 {
5456 	kobject_put(&ext4_feat->f_kobj);
5457 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5458 	kfree(ext4_feat);
5459 }
5460 
5461 /* Shared across all ext4 file systems */
5462 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5463 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5464 
5465 static int __init ext4_init_fs(void)
5466 {
5467 	int i, err;
5468 
5469 	ext4_li_info = NULL;
5470 	mutex_init(&ext4_li_mtx);
5471 
5472 	/* Build-time check for flags consistency */
5473 	ext4_check_flag_values();
5474 
5475 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5476 		mutex_init(&ext4__aio_mutex[i]);
5477 		init_waitqueue_head(&ext4__ioend_wq[i]);
5478 	}
5479 
5480 	err = ext4_init_es();
5481 	if (err)
5482 		return err;
5483 
5484 	err = ext4_init_pageio();
5485 	if (err)
5486 		goto out7;
5487 
5488 	err = ext4_init_system_zone();
5489 	if (err)
5490 		goto out6;
5491 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5492 	if (!ext4_kset) {
5493 		err = -ENOMEM;
5494 		goto out5;
5495 	}
5496 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5497 
5498 	err = ext4_init_feat_adverts();
5499 	if (err)
5500 		goto out4;
5501 
5502 	err = ext4_init_mballoc();
5503 	if (err)
5504 		goto out3;
5505 
5506 	err = ext4_init_xattr();
5507 	if (err)
5508 		goto out2;
5509 	err = init_inodecache();
5510 	if (err)
5511 		goto out1;
5512 	register_as_ext3();
5513 	register_as_ext2();
5514 	err = register_filesystem(&ext4_fs_type);
5515 	if (err)
5516 		goto out;
5517 
5518 	return 0;
5519 out:
5520 	unregister_as_ext2();
5521 	unregister_as_ext3();
5522 	destroy_inodecache();
5523 out1:
5524 	ext4_exit_xattr();
5525 out2:
5526 	ext4_exit_mballoc();
5527 out3:
5528 	ext4_exit_feat_adverts();
5529 out4:
5530 	if (ext4_proc_root)
5531 		remove_proc_entry("fs/ext4", NULL);
5532 	kset_unregister(ext4_kset);
5533 out5:
5534 	ext4_exit_system_zone();
5535 out6:
5536 	ext4_exit_pageio();
5537 out7:
5538 	ext4_exit_es();
5539 
5540 	return err;
5541 }
5542 
5543 static void __exit ext4_exit_fs(void)
5544 {
5545 	ext4_destroy_lazyinit_thread();
5546 	unregister_as_ext2();
5547 	unregister_as_ext3();
5548 	unregister_filesystem(&ext4_fs_type);
5549 	destroy_inodecache();
5550 	ext4_exit_xattr();
5551 	ext4_exit_mballoc();
5552 	ext4_exit_feat_adverts();
5553 	remove_proc_entry("fs/ext4", NULL);
5554 	kset_unregister(ext4_kset);
5555 	ext4_exit_system_zone();
5556 	ext4_exit_pageio();
5557 	ext4_exit_es();
5558 }
5559 
5560 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5561 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5562 MODULE_LICENSE("GPL");
5563 module_init(ext4_init_fs)
5564 module_exit(ext4_exit_fs)
5565