xref: /linux/fs/ext4/super.c (revision 026dadad6b44f0469a475efb4cae48269d8848bd)
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);
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);
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 void __ext4_error(struct super_block *sb, const char *function,
415 		  unsigned int line, const char *fmt, ...)
416 {
417 	struct va_format vaf;
418 	va_list args;
419 
420 	va_start(args, fmt);
421 	vaf.fmt = fmt;
422 	vaf.va = &args;
423 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
424 	       sb->s_id, function, line, current->comm, &vaf);
425 	va_end(args);
426 	save_error_info(sb, function, line);
427 
428 	ext4_handle_error(sb);
429 }
430 
431 void __ext4_error_inode(struct inode *inode, const char *function,
432 			unsigned int line, ext4_fsblk_t block,
433 			const char *fmt, ...)
434 {
435 	va_list args;
436 	struct va_format vaf;
437 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
438 
439 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
440 	es->s_last_error_block = cpu_to_le64(block);
441 	save_error_info(inode->i_sb, function, line);
442 	va_start(args, fmt);
443 	vaf.fmt = fmt;
444 	vaf.va = &args;
445 	if (block)
446 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
447 		       "inode #%lu: block %llu: comm %s: %pV\n",
448 		       inode->i_sb->s_id, function, line, inode->i_ino,
449 		       block, current->comm, &vaf);
450 	else
451 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
452 		       "inode #%lu: comm %s: %pV\n",
453 		       inode->i_sb->s_id, function, line, inode->i_ino,
454 		       current->comm, &vaf);
455 	va_end(args);
456 
457 	ext4_handle_error(inode->i_sb);
458 }
459 
460 void __ext4_error_file(struct file *file, const char *function,
461 		       unsigned int line, ext4_fsblk_t block,
462 		       const char *fmt, ...)
463 {
464 	va_list args;
465 	struct va_format vaf;
466 	struct ext4_super_block *es;
467 	struct inode *inode = file_inode(file);
468 	char pathname[80], *path;
469 
470 	es = EXT4_SB(inode->i_sb)->s_es;
471 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
472 	save_error_info(inode->i_sb, function, line);
473 	path = d_path(&(file->f_path), pathname, sizeof(pathname));
474 	if (IS_ERR(path))
475 		path = "(unknown)";
476 	va_start(args, fmt);
477 	vaf.fmt = fmt;
478 	vaf.va = &args;
479 	if (block)
480 		printk(KERN_CRIT
481 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
482 		       "block %llu: comm %s: path %s: %pV\n",
483 		       inode->i_sb->s_id, function, line, inode->i_ino,
484 		       block, current->comm, path, &vaf);
485 	else
486 		printk(KERN_CRIT
487 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
488 		       "comm %s: path %s: %pV\n",
489 		       inode->i_sb->s_id, function, line, inode->i_ino,
490 		       current->comm, path, &vaf);
491 	va_end(args);
492 
493 	ext4_handle_error(inode->i_sb);
494 }
495 
496 const char *ext4_decode_error(struct super_block *sb, int errno,
497 			      char nbuf[16])
498 {
499 	char *errstr = NULL;
500 
501 	switch (errno) {
502 	case -EIO:
503 		errstr = "IO failure";
504 		break;
505 	case -ENOMEM:
506 		errstr = "Out of memory";
507 		break;
508 	case -EROFS:
509 		if (!sb || (EXT4_SB(sb)->s_journal &&
510 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
511 			errstr = "Journal has aborted";
512 		else
513 			errstr = "Readonly filesystem";
514 		break;
515 	default:
516 		/* If the caller passed in an extra buffer for unknown
517 		 * errors, textualise them now.  Else we just return
518 		 * NULL. */
519 		if (nbuf) {
520 			/* Check for truncated error codes... */
521 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
522 				errstr = nbuf;
523 		}
524 		break;
525 	}
526 
527 	return errstr;
528 }
529 
530 /* __ext4_std_error decodes expected errors from journaling functions
531  * automatically and invokes the appropriate error response.  */
532 
533 void __ext4_std_error(struct super_block *sb, const char *function,
534 		      unsigned int line, int errno)
535 {
536 	char nbuf[16];
537 	const char *errstr;
538 
539 	/* Special case: if the error is EROFS, and we're not already
540 	 * inside a transaction, then there's really no point in logging
541 	 * an error. */
542 	if (errno == -EROFS && journal_current_handle() == NULL &&
543 	    (sb->s_flags & MS_RDONLY))
544 		return;
545 
546 	errstr = ext4_decode_error(sb, errno, nbuf);
547 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
548 	       sb->s_id, function, line, errstr);
549 	save_error_info(sb, function, line);
550 
551 	ext4_handle_error(sb);
552 }
553 
554 /*
555  * ext4_abort is a much stronger failure handler than ext4_error.  The
556  * abort function may be used to deal with unrecoverable failures such
557  * as journal IO errors or ENOMEM at a critical moment in log management.
558  *
559  * We unconditionally force the filesystem into an ABORT|READONLY state,
560  * unless the error response on the fs has been set to panic in which
561  * case we take the easy way out and panic immediately.
562  */
563 
564 void __ext4_abort(struct super_block *sb, const char *function,
565 		unsigned int line, const char *fmt, ...)
566 {
567 	va_list args;
568 
569 	save_error_info(sb, function, line);
570 	va_start(args, fmt);
571 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
572 	       function, line);
573 	vprintk(fmt, args);
574 	printk("\n");
575 	va_end(args);
576 
577 	if ((sb->s_flags & MS_RDONLY) == 0) {
578 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
579 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
580 		/*
581 		 * Make sure updated value of ->s_mount_flags will be visible
582 		 * before ->s_flags update
583 		 */
584 		smp_wmb();
585 		sb->s_flags |= MS_RDONLY;
586 		if (EXT4_SB(sb)->s_journal)
587 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
588 		save_error_info(sb, function, line);
589 	}
590 	if (test_opt(sb, ERRORS_PANIC))
591 		panic("EXT4-fs panic from previous error\n");
592 }
593 
594 void __ext4_msg(struct super_block *sb,
595 		const char *prefix, const char *fmt, ...)
596 {
597 	struct va_format vaf;
598 	va_list args;
599 
600 	va_start(args, fmt);
601 	vaf.fmt = fmt;
602 	vaf.va = &args;
603 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
604 	va_end(args);
605 }
606 
607 void __ext4_warning(struct super_block *sb, const char *function,
608 		    unsigned int line, const char *fmt, ...)
609 {
610 	struct va_format vaf;
611 	va_list args;
612 
613 	va_start(args, fmt);
614 	vaf.fmt = fmt;
615 	vaf.va = &args;
616 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
617 	       sb->s_id, function, line, &vaf);
618 	va_end(args);
619 }
620 
621 void __ext4_grp_locked_error(const char *function, unsigned int line,
622 			     struct super_block *sb, ext4_group_t grp,
623 			     unsigned long ino, ext4_fsblk_t block,
624 			     const char *fmt, ...)
625 __releases(bitlock)
626 __acquires(bitlock)
627 {
628 	struct va_format vaf;
629 	va_list args;
630 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
631 
632 	es->s_last_error_ino = cpu_to_le32(ino);
633 	es->s_last_error_block = cpu_to_le64(block);
634 	__save_error_info(sb, function, line);
635 
636 	va_start(args, fmt);
637 
638 	vaf.fmt = fmt;
639 	vaf.va = &args;
640 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
641 	       sb->s_id, function, line, grp);
642 	if (ino)
643 		printk(KERN_CONT "inode %lu: ", ino);
644 	if (block)
645 		printk(KERN_CONT "block %llu:", (unsigned long long) block);
646 	printk(KERN_CONT "%pV\n", &vaf);
647 	va_end(args);
648 
649 	if (test_opt(sb, ERRORS_CONT)) {
650 		ext4_commit_super(sb, 0);
651 		return;
652 	}
653 
654 	ext4_unlock_group(sb, grp);
655 	ext4_handle_error(sb);
656 	/*
657 	 * We only get here in the ERRORS_RO case; relocking the group
658 	 * may be dangerous, but nothing bad will happen since the
659 	 * filesystem will have already been marked read/only and the
660 	 * journal has been aborted.  We return 1 as a hint to callers
661 	 * who might what to use the return value from
662 	 * ext4_grp_locked_error() to distinguish between the
663 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
664 	 * aggressively from the ext4 function in question, with a
665 	 * more appropriate error code.
666 	 */
667 	ext4_lock_group(sb, grp);
668 	return;
669 }
670 
671 void ext4_update_dynamic_rev(struct super_block *sb)
672 {
673 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
674 
675 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
676 		return;
677 
678 	ext4_warning(sb,
679 		     "updating to rev %d because of new feature flag, "
680 		     "running e2fsck is recommended",
681 		     EXT4_DYNAMIC_REV);
682 
683 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
684 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
685 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
686 	/* leave es->s_feature_*compat flags alone */
687 	/* es->s_uuid will be set by e2fsck if empty */
688 
689 	/*
690 	 * The rest of the superblock fields should be zero, and if not it
691 	 * means they are likely already in use, so leave them alone.  We
692 	 * can leave it up to e2fsck to clean up any inconsistencies there.
693 	 */
694 }
695 
696 /*
697  * Open the external journal device
698  */
699 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
700 {
701 	struct block_device *bdev;
702 	char b[BDEVNAME_SIZE];
703 
704 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
705 	if (IS_ERR(bdev))
706 		goto fail;
707 	return bdev;
708 
709 fail:
710 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
711 			__bdevname(dev, b), PTR_ERR(bdev));
712 	return NULL;
713 }
714 
715 /*
716  * Release the journal device
717  */
718 static void ext4_blkdev_put(struct block_device *bdev)
719 {
720 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
721 }
722 
723 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
724 {
725 	struct block_device *bdev;
726 	bdev = sbi->journal_bdev;
727 	if (bdev) {
728 		ext4_blkdev_put(bdev);
729 		sbi->journal_bdev = NULL;
730 	}
731 }
732 
733 static inline struct inode *orphan_list_entry(struct list_head *l)
734 {
735 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
736 }
737 
738 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
739 {
740 	struct list_head *l;
741 
742 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
743 		 le32_to_cpu(sbi->s_es->s_last_orphan));
744 
745 	printk(KERN_ERR "sb_info orphan list:\n");
746 	list_for_each(l, &sbi->s_orphan) {
747 		struct inode *inode = orphan_list_entry(l);
748 		printk(KERN_ERR "  "
749 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
750 		       inode->i_sb->s_id, inode->i_ino, inode,
751 		       inode->i_mode, inode->i_nlink,
752 		       NEXT_ORPHAN(inode));
753 	}
754 }
755 
756 static void ext4_put_super(struct super_block *sb)
757 {
758 	struct ext4_sb_info *sbi = EXT4_SB(sb);
759 	struct ext4_super_block *es = sbi->s_es;
760 	int i, err;
761 
762 	ext4_unregister_li_request(sb);
763 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
764 
765 	flush_workqueue(sbi->unrsv_conversion_wq);
766 	flush_workqueue(sbi->rsv_conversion_wq);
767 	destroy_workqueue(sbi->unrsv_conversion_wq);
768 	destroy_workqueue(sbi->rsv_conversion_wq);
769 
770 	if (sbi->s_journal) {
771 		err = jbd2_journal_destroy(sbi->s_journal);
772 		sbi->s_journal = NULL;
773 		if (err < 0)
774 			ext4_abort(sb, "Couldn't clean up the journal");
775 	}
776 
777 	ext4_es_unregister_shrinker(sbi);
778 	del_timer(&sbi->s_err_report);
779 	ext4_release_system_zone(sb);
780 	ext4_mb_release(sb);
781 	ext4_ext_release(sb);
782 	ext4_xattr_put_super(sb);
783 
784 	if (!(sb->s_flags & MS_RDONLY)) {
785 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
786 		es->s_state = cpu_to_le16(sbi->s_mount_state);
787 	}
788 	if (!(sb->s_flags & MS_RDONLY))
789 		ext4_commit_super(sb, 1);
790 
791 	if (sbi->s_proc) {
792 		remove_proc_entry("options", sbi->s_proc);
793 		remove_proc_entry(sb->s_id, ext4_proc_root);
794 	}
795 	kobject_del(&sbi->s_kobj);
796 
797 	for (i = 0; i < sbi->s_gdb_count; i++)
798 		brelse(sbi->s_group_desc[i]);
799 	ext4_kvfree(sbi->s_group_desc);
800 	ext4_kvfree(sbi->s_flex_groups);
801 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
802 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
803 	percpu_counter_destroy(&sbi->s_dirs_counter);
804 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
805 	percpu_counter_destroy(&sbi->s_extent_cache_cnt);
806 	brelse(sbi->s_sbh);
807 #ifdef CONFIG_QUOTA
808 	for (i = 0; i < MAXQUOTAS; i++)
809 		kfree(sbi->s_qf_names[i]);
810 #endif
811 
812 	/* Debugging code just in case the in-memory inode orphan list
813 	 * isn't empty.  The on-disk one can be non-empty if we've
814 	 * detected an error and taken the fs readonly, but the
815 	 * in-memory list had better be clean by this point. */
816 	if (!list_empty(&sbi->s_orphan))
817 		dump_orphan_list(sb, sbi);
818 	J_ASSERT(list_empty(&sbi->s_orphan));
819 
820 	invalidate_bdev(sb->s_bdev);
821 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
822 		/*
823 		 * Invalidate the journal device's buffers.  We don't want them
824 		 * floating about in memory - the physical journal device may
825 		 * hotswapped, and it breaks the `ro-after' testing code.
826 		 */
827 		sync_blockdev(sbi->journal_bdev);
828 		invalidate_bdev(sbi->journal_bdev);
829 		ext4_blkdev_remove(sbi);
830 	}
831 	if (sbi->s_mmp_tsk)
832 		kthread_stop(sbi->s_mmp_tsk);
833 	sb->s_fs_info = NULL;
834 	/*
835 	 * Now that we are completely done shutting down the
836 	 * superblock, we need to actually destroy the kobject.
837 	 */
838 	kobject_put(&sbi->s_kobj);
839 	wait_for_completion(&sbi->s_kobj_unregister);
840 	if (sbi->s_chksum_driver)
841 		crypto_free_shash(sbi->s_chksum_driver);
842 	kfree(sbi->s_blockgroup_lock);
843 	kfree(sbi);
844 }
845 
846 static struct kmem_cache *ext4_inode_cachep;
847 
848 /*
849  * Called inside transaction, so use GFP_NOFS
850  */
851 static struct inode *ext4_alloc_inode(struct super_block *sb)
852 {
853 	struct ext4_inode_info *ei;
854 
855 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
856 	if (!ei)
857 		return NULL;
858 
859 	ei->vfs_inode.i_version = 1;
860 	INIT_LIST_HEAD(&ei->i_prealloc_list);
861 	spin_lock_init(&ei->i_prealloc_lock);
862 	ext4_es_init_tree(&ei->i_es_tree);
863 	rwlock_init(&ei->i_es_lock);
864 	INIT_LIST_HEAD(&ei->i_es_lru);
865 	ei->i_es_lru_nr = 0;
866 	ei->i_touch_when = 0;
867 	ei->i_reserved_data_blocks = 0;
868 	ei->i_reserved_meta_blocks = 0;
869 	ei->i_allocated_meta_blocks = 0;
870 	ei->i_da_metadata_calc_len = 0;
871 	ei->i_da_metadata_calc_last_lblock = 0;
872 	spin_lock_init(&(ei->i_block_reservation_lock));
873 #ifdef CONFIG_QUOTA
874 	ei->i_reserved_quota = 0;
875 #endif
876 	ei->jinode = NULL;
877 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
878 	INIT_LIST_HEAD(&ei->i_unrsv_conversion_list);
879 	spin_lock_init(&ei->i_completed_io_lock);
880 	ei->i_sync_tid = 0;
881 	ei->i_datasync_tid = 0;
882 	atomic_set(&ei->i_ioend_count, 0);
883 	atomic_set(&ei->i_unwritten, 0);
884 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
885 	INIT_WORK(&ei->i_unrsv_conversion_work, ext4_end_io_unrsv_work);
886 
887 	return &ei->vfs_inode;
888 }
889 
890 static int ext4_drop_inode(struct inode *inode)
891 {
892 	int drop = generic_drop_inode(inode);
893 
894 	trace_ext4_drop_inode(inode, drop);
895 	return drop;
896 }
897 
898 static void ext4_i_callback(struct rcu_head *head)
899 {
900 	struct inode *inode = container_of(head, struct inode, i_rcu);
901 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
902 }
903 
904 static void ext4_destroy_inode(struct inode *inode)
905 {
906 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
907 		ext4_msg(inode->i_sb, KERN_ERR,
908 			 "Inode %lu (%p): orphan list check failed!",
909 			 inode->i_ino, EXT4_I(inode));
910 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
911 				EXT4_I(inode), sizeof(struct ext4_inode_info),
912 				true);
913 		dump_stack();
914 	}
915 	call_rcu(&inode->i_rcu, ext4_i_callback);
916 }
917 
918 static void init_once(void *foo)
919 {
920 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
921 
922 	INIT_LIST_HEAD(&ei->i_orphan);
923 	init_rwsem(&ei->xattr_sem);
924 	init_rwsem(&ei->i_data_sem);
925 	inode_init_once(&ei->vfs_inode);
926 }
927 
928 static int init_inodecache(void)
929 {
930 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
931 					     sizeof(struct ext4_inode_info),
932 					     0, (SLAB_RECLAIM_ACCOUNT|
933 						SLAB_MEM_SPREAD),
934 					     init_once);
935 	if (ext4_inode_cachep == NULL)
936 		return -ENOMEM;
937 	return 0;
938 }
939 
940 static void destroy_inodecache(void)
941 {
942 	/*
943 	 * Make sure all delayed rcu free inodes are flushed before we
944 	 * destroy cache.
945 	 */
946 	rcu_barrier();
947 	kmem_cache_destroy(ext4_inode_cachep);
948 }
949 
950 void ext4_clear_inode(struct inode *inode)
951 {
952 	invalidate_inode_buffers(inode);
953 	clear_inode(inode);
954 	dquot_drop(inode);
955 	ext4_discard_preallocations(inode);
956 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
957 	ext4_es_lru_del(inode);
958 	if (EXT4_I(inode)->jinode) {
959 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
960 					       EXT4_I(inode)->jinode);
961 		jbd2_free_inode(EXT4_I(inode)->jinode);
962 		EXT4_I(inode)->jinode = NULL;
963 	}
964 }
965 
966 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
967 					u64 ino, u32 generation)
968 {
969 	struct inode *inode;
970 
971 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
972 		return ERR_PTR(-ESTALE);
973 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
974 		return ERR_PTR(-ESTALE);
975 
976 	/* iget isn't really right if the inode is currently unallocated!!
977 	 *
978 	 * ext4_read_inode will return a bad_inode if the inode had been
979 	 * deleted, so we should be safe.
980 	 *
981 	 * Currently we don't know the generation for parent directory, so
982 	 * a generation of 0 means "accept any"
983 	 */
984 	inode = ext4_iget(sb, ino);
985 	if (IS_ERR(inode))
986 		return ERR_CAST(inode);
987 	if (generation && inode->i_generation != generation) {
988 		iput(inode);
989 		return ERR_PTR(-ESTALE);
990 	}
991 
992 	return inode;
993 }
994 
995 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
996 					int fh_len, int fh_type)
997 {
998 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
999 				    ext4_nfs_get_inode);
1000 }
1001 
1002 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1003 					int fh_len, int fh_type)
1004 {
1005 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1006 				    ext4_nfs_get_inode);
1007 }
1008 
1009 /*
1010  * Try to release metadata pages (indirect blocks, directories) which are
1011  * mapped via the block device.  Since these pages could have journal heads
1012  * which would prevent try_to_free_buffers() from freeing them, we must use
1013  * jbd2 layer's try_to_free_buffers() function to release them.
1014  */
1015 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1016 				 gfp_t wait)
1017 {
1018 	journal_t *journal = EXT4_SB(sb)->s_journal;
1019 
1020 	WARN_ON(PageChecked(page));
1021 	if (!page_has_buffers(page))
1022 		return 0;
1023 	if (journal)
1024 		return jbd2_journal_try_to_free_buffers(journal, page,
1025 							wait & ~__GFP_WAIT);
1026 	return try_to_free_buffers(page);
1027 }
1028 
1029 #ifdef CONFIG_QUOTA
1030 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1031 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1032 
1033 static int ext4_write_dquot(struct dquot *dquot);
1034 static int ext4_acquire_dquot(struct dquot *dquot);
1035 static int ext4_release_dquot(struct dquot *dquot);
1036 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1037 static int ext4_write_info(struct super_block *sb, int type);
1038 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1039 			 struct path *path);
1040 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1041 				 int format_id);
1042 static int ext4_quota_off(struct super_block *sb, int type);
1043 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1044 static int ext4_quota_on_mount(struct super_block *sb, int type);
1045 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1046 			       size_t len, loff_t off);
1047 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1048 				const char *data, size_t len, loff_t off);
1049 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1050 			     unsigned int flags);
1051 static int ext4_enable_quotas(struct super_block *sb);
1052 
1053 static const struct dquot_operations ext4_quota_operations = {
1054 	.get_reserved_space = ext4_get_reserved_space,
1055 	.write_dquot	= ext4_write_dquot,
1056 	.acquire_dquot	= ext4_acquire_dquot,
1057 	.release_dquot	= ext4_release_dquot,
1058 	.mark_dirty	= ext4_mark_dquot_dirty,
1059 	.write_info	= ext4_write_info,
1060 	.alloc_dquot	= dquot_alloc,
1061 	.destroy_dquot	= dquot_destroy,
1062 };
1063 
1064 static const struct quotactl_ops ext4_qctl_operations = {
1065 	.quota_on	= ext4_quota_on,
1066 	.quota_off	= ext4_quota_off,
1067 	.quota_sync	= dquot_quota_sync,
1068 	.get_info	= dquot_get_dqinfo,
1069 	.set_info	= dquot_set_dqinfo,
1070 	.get_dqblk	= dquot_get_dqblk,
1071 	.set_dqblk	= dquot_set_dqblk
1072 };
1073 
1074 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1075 	.quota_on_meta	= ext4_quota_on_sysfile,
1076 	.quota_off	= ext4_quota_off_sysfile,
1077 	.quota_sync	= dquot_quota_sync,
1078 	.get_info	= dquot_get_dqinfo,
1079 	.set_info	= dquot_set_dqinfo,
1080 	.get_dqblk	= dquot_get_dqblk,
1081 	.set_dqblk	= dquot_set_dqblk
1082 };
1083 #endif
1084 
1085 static const struct super_operations ext4_sops = {
1086 	.alloc_inode	= ext4_alloc_inode,
1087 	.destroy_inode	= ext4_destroy_inode,
1088 	.write_inode	= ext4_write_inode,
1089 	.dirty_inode	= ext4_dirty_inode,
1090 	.drop_inode	= ext4_drop_inode,
1091 	.evict_inode	= ext4_evict_inode,
1092 	.put_super	= ext4_put_super,
1093 	.sync_fs	= ext4_sync_fs,
1094 	.freeze_fs	= ext4_freeze,
1095 	.unfreeze_fs	= ext4_unfreeze,
1096 	.statfs		= ext4_statfs,
1097 	.remount_fs	= ext4_remount,
1098 	.show_options	= ext4_show_options,
1099 #ifdef CONFIG_QUOTA
1100 	.quota_read	= ext4_quota_read,
1101 	.quota_write	= ext4_quota_write,
1102 #endif
1103 	.bdev_try_to_free_page = bdev_try_to_free_page,
1104 };
1105 
1106 static const struct super_operations ext4_nojournal_sops = {
1107 	.alloc_inode	= ext4_alloc_inode,
1108 	.destroy_inode	= ext4_destroy_inode,
1109 	.write_inode	= ext4_write_inode,
1110 	.dirty_inode	= ext4_dirty_inode,
1111 	.drop_inode	= ext4_drop_inode,
1112 	.evict_inode	= ext4_evict_inode,
1113 	.sync_fs	= ext4_sync_fs_nojournal,
1114 	.put_super	= ext4_put_super,
1115 	.statfs		= ext4_statfs,
1116 	.remount_fs	= ext4_remount,
1117 	.show_options	= ext4_show_options,
1118 #ifdef CONFIG_QUOTA
1119 	.quota_read	= ext4_quota_read,
1120 	.quota_write	= ext4_quota_write,
1121 #endif
1122 	.bdev_try_to_free_page = bdev_try_to_free_page,
1123 };
1124 
1125 static const struct export_operations ext4_export_ops = {
1126 	.fh_to_dentry = ext4_fh_to_dentry,
1127 	.fh_to_parent = ext4_fh_to_parent,
1128 	.get_parent = ext4_get_parent,
1129 };
1130 
1131 enum {
1132 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1133 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1134 	Opt_nouid32, Opt_debug, Opt_removed,
1135 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1136 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1137 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1138 	Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1139 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1140 	Opt_data_err_abort, Opt_data_err_ignore,
1141 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1142 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1143 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1144 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1145 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1146 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1147 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1148 	Opt_dioread_nolock, Opt_dioread_lock,
1149 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1150 	Opt_max_dir_size_kb,
1151 };
1152 
1153 static const match_table_t tokens = {
1154 	{Opt_bsd_df, "bsddf"},
1155 	{Opt_minix_df, "minixdf"},
1156 	{Opt_grpid, "grpid"},
1157 	{Opt_grpid, "bsdgroups"},
1158 	{Opt_nogrpid, "nogrpid"},
1159 	{Opt_nogrpid, "sysvgroups"},
1160 	{Opt_resgid, "resgid=%u"},
1161 	{Opt_resuid, "resuid=%u"},
1162 	{Opt_sb, "sb=%u"},
1163 	{Opt_err_cont, "errors=continue"},
1164 	{Opt_err_panic, "errors=panic"},
1165 	{Opt_err_ro, "errors=remount-ro"},
1166 	{Opt_nouid32, "nouid32"},
1167 	{Opt_debug, "debug"},
1168 	{Opt_removed, "oldalloc"},
1169 	{Opt_removed, "orlov"},
1170 	{Opt_user_xattr, "user_xattr"},
1171 	{Opt_nouser_xattr, "nouser_xattr"},
1172 	{Opt_acl, "acl"},
1173 	{Opt_noacl, "noacl"},
1174 	{Opt_noload, "norecovery"},
1175 	{Opt_noload, "noload"},
1176 	{Opt_removed, "nobh"},
1177 	{Opt_removed, "bh"},
1178 	{Opt_commit, "commit=%u"},
1179 	{Opt_min_batch_time, "min_batch_time=%u"},
1180 	{Opt_max_batch_time, "max_batch_time=%u"},
1181 	{Opt_journal_dev, "journal_dev=%u"},
1182 	{Opt_journal_checksum, "journal_checksum"},
1183 	{Opt_journal_async_commit, "journal_async_commit"},
1184 	{Opt_abort, "abort"},
1185 	{Opt_data_journal, "data=journal"},
1186 	{Opt_data_ordered, "data=ordered"},
1187 	{Opt_data_writeback, "data=writeback"},
1188 	{Opt_data_err_abort, "data_err=abort"},
1189 	{Opt_data_err_ignore, "data_err=ignore"},
1190 	{Opt_offusrjquota, "usrjquota="},
1191 	{Opt_usrjquota, "usrjquota=%s"},
1192 	{Opt_offgrpjquota, "grpjquota="},
1193 	{Opt_grpjquota, "grpjquota=%s"},
1194 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1195 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1196 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1197 	{Opt_grpquota, "grpquota"},
1198 	{Opt_noquota, "noquota"},
1199 	{Opt_quota, "quota"},
1200 	{Opt_usrquota, "usrquota"},
1201 	{Opt_barrier, "barrier=%u"},
1202 	{Opt_barrier, "barrier"},
1203 	{Opt_nobarrier, "nobarrier"},
1204 	{Opt_i_version, "i_version"},
1205 	{Opt_stripe, "stripe=%u"},
1206 	{Opt_delalloc, "delalloc"},
1207 	{Opt_nodelalloc, "nodelalloc"},
1208 	{Opt_removed, "mblk_io_submit"},
1209 	{Opt_removed, "nomblk_io_submit"},
1210 	{Opt_block_validity, "block_validity"},
1211 	{Opt_noblock_validity, "noblock_validity"},
1212 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1213 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1214 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1215 	{Opt_auto_da_alloc, "auto_da_alloc"},
1216 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1217 	{Opt_dioread_nolock, "dioread_nolock"},
1218 	{Opt_dioread_lock, "dioread_lock"},
1219 	{Opt_discard, "discard"},
1220 	{Opt_nodiscard, "nodiscard"},
1221 	{Opt_init_itable, "init_itable=%u"},
1222 	{Opt_init_itable, "init_itable"},
1223 	{Opt_noinit_itable, "noinit_itable"},
1224 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1225 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1226 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1227 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1228 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1229 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1230 	{Opt_err, NULL},
1231 };
1232 
1233 static ext4_fsblk_t get_sb_block(void **data)
1234 {
1235 	ext4_fsblk_t	sb_block;
1236 	char		*options = (char *) *data;
1237 
1238 	if (!options || strncmp(options, "sb=", 3) != 0)
1239 		return 1;	/* Default location */
1240 
1241 	options += 3;
1242 	/* TODO: use simple_strtoll with >32bit ext4 */
1243 	sb_block = simple_strtoul(options, &options, 0);
1244 	if (*options && *options != ',') {
1245 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1246 		       (char *) *data);
1247 		return 1;
1248 	}
1249 	if (*options == ',')
1250 		options++;
1251 	*data = (void *) options;
1252 
1253 	return sb_block;
1254 }
1255 
1256 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1257 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1258 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1259 
1260 #ifdef CONFIG_QUOTA
1261 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1262 {
1263 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1264 	char *qname;
1265 	int ret = -1;
1266 
1267 	if (sb_any_quota_loaded(sb) &&
1268 		!sbi->s_qf_names[qtype]) {
1269 		ext4_msg(sb, KERN_ERR,
1270 			"Cannot change journaled "
1271 			"quota options when quota turned on");
1272 		return -1;
1273 	}
1274 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1275 		ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1276 			 "when QUOTA feature is enabled");
1277 		return -1;
1278 	}
1279 	qname = match_strdup(args);
1280 	if (!qname) {
1281 		ext4_msg(sb, KERN_ERR,
1282 			"Not enough memory for storing quotafile name");
1283 		return -1;
1284 	}
1285 	if (sbi->s_qf_names[qtype]) {
1286 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1287 			ret = 1;
1288 		else
1289 			ext4_msg(sb, KERN_ERR,
1290 				 "%s quota file already specified",
1291 				 QTYPE2NAME(qtype));
1292 		goto errout;
1293 	}
1294 	if (strchr(qname, '/')) {
1295 		ext4_msg(sb, KERN_ERR,
1296 			"quotafile must be on filesystem root");
1297 		goto errout;
1298 	}
1299 	sbi->s_qf_names[qtype] = qname;
1300 	set_opt(sb, QUOTA);
1301 	return 1;
1302 errout:
1303 	kfree(qname);
1304 	return ret;
1305 }
1306 
1307 static int clear_qf_name(struct super_block *sb, int qtype)
1308 {
1309 
1310 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1311 
1312 	if (sb_any_quota_loaded(sb) &&
1313 		sbi->s_qf_names[qtype]) {
1314 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1315 			" when quota turned on");
1316 		return -1;
1317 	}
1318 	kfree(sbi->s_qf_names[qtype]);
1319 	sbi->s_qf_names[qtype] = NULL;
1320 	return 1;
1321 }
1322 #endif
1323 
1324 #define MOPT_SET	0x0001
1325 #define MOPT_CLEAR	0x0002
1326 #define MOPT_NOSUPPORT	0x0004
1327 #define MOPT_EXPLICIT	0x0008
1328 #define MOPT_CLEAR_ERR	0x0010
1329 #define MOPT_GTE0	0x0020
1330 #ifdef CONFIG_QUOTA
1331 #define MOPT_Q		0
1332 #define MOPT_QFMT	0x0040
1333 #else
1334 #define MOPT_Q		MOPT_NOSUPPORT
1335 #define MOPT_QFMT	MOPT_NOSUPPORT
1336 #endif
1337 #define MOPT_DATAJ	0x0080
1338 #define MOPT_NO_EXT2	0x0100
1339 #define MOPT_NO_EXT3	0x0200
1340 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1341 
1342 static const struct mount_opts {
1343 	int	token;
1344 	int	mount_opt;
1345 	int	flags;
1346 } ext4_mount_opts[] = {
1347 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1348 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1349 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1350 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1351 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1352 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1353 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1354 	 MOPT_EXT4_ONLY | MOPT_SET},
1355 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1356 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1357 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1358 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1359 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1360 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1361 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1362 	 MOPT_EXT4_ONLY | MOPT_CLEAR | MOPT_EXPLICIT},
1363 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1364 	 MOPT_EXT4_ONLY | MOPT_SET},
1365 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1366 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1367 	 MOPT_EXT4_ONLY | MOPT_SET},
1368 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1369 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1370 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1371 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1372 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1373 	 MOPT_NO_EXT2 | MOPT_SET},
1374 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1375 	 MOPT_NO_EXT2 | MOPT_CLEAR},
1376 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1377 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1378 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1379 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1380 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1381 	{Opt_commit, 0, MOPT_GTE0},
1382 	{Opt_max_batch_time, 0, MOPT_GTE0},
1383 	{Opt_min_batch_time, 0, MOPT_GTE0},
1384 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1385 	{Opt_init_itable, 0, MOPT_GTE0},
1386 	{Opt_stripe, 0, MOPT_GTE0},
1387 	{Opt_resuid, 0, MOPT_GTE0},
1388 	{Opt_resgid, 0, MOPT_GTE0},
1389 	{Opt_journal_dev, 0, MOPT_GTE0},
1390 	{Opt_journal_ioprio, 0, MOPT_GTE0},
1391 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1392 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1393 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1394 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1395 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1396 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1397 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1398 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1399 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1400 #else
1401 	{Opt_acl, 0, MOPT_NOSUPPORT},
1402 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1403 #endif
1404 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1405 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1406 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1407 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1408 							MOPT_SET | MOPT_Q},
1409 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1410 							MOPT_SET | MOPT_Q},
1411 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1412 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1413 	{Opt_usrjquota, 0, MOPT_Q},
1414 	{Opt_grpjquota, 0, MOPT_Q},
1415 	{Opt_offusrjquota, 0, MOPT_Q},
1416 	{Opt_offgrpjquota, 0, MOPT_Q},
1417 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1418 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1419 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1420 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1421 	{Opt_err, 0, 0}
1422 };
1423 
1424 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1425 			    substring_t *args, unsigned long *journal_devnum,
1426 			    unsigned int *journal_ioprio, int is_remount)
1427 {
1428 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1429 	const struct mount_opts *m;
1430 	kuid_t uid;
1431 	kgid_t gid;
1432 	int arg = 0;
1433 
1434 #ifdef CONFIG_QUOTA
1435 	if (token == Opt_usrjquota)
1436 		return set_qf_name(sb, USRQUOTA, &args[0]);
1437 	else if (token == Opt_grpjquota)
1438 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1439 	else if (token == Opt_offusrjquota)
1440 		return clear_qf_name(sb, USRQUOTA);
1441 	else if (token == Opt_offgrpjquota)
1442 		return clear_qf_name(sb, GRPQUOTA);
1443 #endif
1444 	switch (token) {
1445 	case Opt_noacl:
1446 	case Opt_nouser_xattr:
1447 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1448 		break;
1449 	case Opt_sb:
1450 		return 1;	/* handled by get_sb_block() */
1451 	case Opt_removed:
1452 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1453 		return 1;
1454 	case Opt_abort:
1455 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1456 		return 1;
1457 	case Opt_i_version:
1458 		sb->s_flags |= MS_I_VERSION;
1459 		return 1;
1460 	}
1461 
1462 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1463 		if (token == m->token)
1464 			break;
1465 
1466 	if (m->token == Opt_err) {
1467 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1468 			 "or missing value", opt);
1469 		return -1;
1470 	}
1471 
1472 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1473 		ext4_msg(sb, KERN_ERR,
1474 			 "Mount option \"%s\" incompatible with ext2", opt);
1475 		return -1;
1476 	}
1477 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1478 		ext4_msg(sb, KERN_ERR,
1479 			 "Mount option \"%s\" incompatible with ext3", opt);
1480 		return -1;
1481 	}
1482 
1483 	if (args->from && match_int(args, &arg))
1484 		return -1;
1485 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1486 		return -1;
1487 	if (m->flags & MOPT_EXPLICIT)
1488 		set_opt2(sb, EXPLICIT_DELALLOC);
1489 	if (m->flags & MOPT_CLEAR_ERR)
1490 		clear_opt(sb, ERRORS_MASK);
1491 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1492 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1493 			 "options when quota turned on");
1494 		return -1;
1495 	}
1496 
1497 	if (m->flags & MOPT_NOSUPPORT) {
1498 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1499 	} else if (token == Opt_commit) {
1500 		if (arg == 0)
1501 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1502 		sbi->s_commit_interval = HZ * arg;
1503 	} else if (token == Opt_max_batch_time) {
1504 		if (arg == 0)
1505 			arg = EXT4_DEF_MAX_BATCH_TIME;
1506 		sbi->s_max_batch_time = arg;
1507 	} else if (token == Opt_min_batch_time) {
1508 		sbi->s_min_batch_time = arg;
1509 	} else if (token == Opt_inode_readahead_blks) {
1510 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1511 			ext4_msg(sb, KERN_ERR,
1512 				 "EXT4-fs: inode_readahead_blks must be "
1513 				 "0 or a power of 2 smaller than 2^31");
1514 			return -1;
1515 		}
1516 		sbi->s_inode_readahead_blks = arg;
1517 	} else if (token == Opt_init_itable) {
1518 		set_opt(sb, INIT_INODE_TABLE);
1519 		if (!args->from)
1520 			arg = EXT4_DEF_LI_WAIT_MULT;
1521 		sbi->s_li_wait_mult = arg;
1522 	} else if (token == Opt_max_dir_size_kb) {
1523 		sbi->s_max_dir_size_kb = arg;
1524 	} else if (token == Opt_stripe) {
1525 		sbi->s_stripe = arg;
1526 	} else if (token == Opt_resuid) {
1527 		uid = make_kuid(current_user_ns(), arg);
1528 		if (!uid_valid(uid)) {
1529 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1530 			return -1;
1531 		}
1532 		sbi->s_resuid = uid;
1533 	} else if (token == Opt_resgid) {
1534 		gid = make_kgid(current_user_ns(), arg);
1535 		if (!gid_valid(gid)) {
1536 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1537 			return -1;
1538 		}
1539 		sbi->s_resgid = gid;
1540 	} else if (token == Opt_journal_dev) {
1541 		if (is_remount) {
1542 			ext4_msg(sb, KERN_ERR,
1543 				 "Cannot specify journal on remount");
1544 			return -1;
1545 		}
1546 		*journal_devnum = arg;
1547 	} else if (token == Opt_journal_ioprio) {
1548 		if (arg > 7) {
1549 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1550 				 " (must be 0-7)");
1551 			return -1;
1552 		}
1553 		*journal_ioprio =
1554 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1555 	} else if (m->flags & MOPT_DATAJ) {
1556 		if (is_remount) {
1557 			if (!sbi->s_journal)
1558 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1559 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1560 				ext4_msg(sb, KERN_ERR,
1561 					 "Cannot change data mode on remount");
1562 				return -1;
1563 			}
1564 		} else {
1565 			clear_opt(sb, DATA_FLAGS);
1566 			sbi->s_mount_opt |= m->mount_opt;
1567 		}
1568 #ifdef CONFIG_QUOTA
1569 	} else if (m->flags & MOPT_QFMT) {
1570 		if (sb_any_quota_loaded(sb) &&
1571 		    sbi->s_jquota_fmt != m->mount_opt) {
1572 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1573 				 "quota options when quota turned on");
1574 			return -1;
1575 		}
1576 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1577 					       EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1578 			ext4_msg(sb, KERN_ERR,
1579 				 "Cannot set journaled quota options "
1580 				 "when QUOTA feature is enabled");
1581 			return -1;
1582 		}
1583 		sbi->s_jquota_fmt = m->mount_opt;
1584 #endif
1585 	} else {
1586 		if (!args->from)
1587 			arg = 1;
1588 		if (m->flags & MOPT_CLEAR)
1589 			arg = !arg;
1590 		else if (unlikely(!(m->flags & MOPT_SET))) {
1591 			ext4_msg(sb, KERN_WARNING,
1592 				 "buggy handling of option %s", opt);
1593 			WARN_ON(1);
1594 			return -1;
1595 		}
1596 		if (arg != 0)
1597 			sbi->s_mount_opt |= m->mount_opt;
1598 		else
1599 			sbi->s_mount_opt &= ~m->mount_opt;
1600 	}
1601 	return 1;
1602 }
1603 
1604 static int parse_options(char *options, struct super_block *sb,
1605 			 unsigned long *journal_devnum,
1606 			 unsigned int *journal_ioprio,
1607 			 int is_remount)
1608 {
1609 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1610 	char *p;
1611 	substring_t args[MAX_OPT_ARGS];
1612 	int token;
1613 
1614 	if (!options)
1615 		return 1;
1616 
1617 	while ((p = strsep(&options, ",")) != NULL) {
1618 		if (!*p)
1619 			continue;
1620 		/*
1621 		 * Initialize args struct so we know whether arg was
1622 		 * found; some options take optional arguments.
1623 		 */
1624 		args[0].to = args[0].from = NULL;
1625 		token = match_token(p, tokens, args);
1626 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1627 				     journal_ioprio, is_remount) < 0)
1628 			return 0;
1629 	}
1630 #ifdef CONFIG_QUOTA
1631 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1632 	    (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1633 		ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1634 			 "feature is enabled");
1635 		return 0;
1636 	}
1637 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1638 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1639 			clear_opt(sb, USRQUOTA);
1640 
1641 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1642 			clear_opt(sb, GRPQUOTA);
1643 
1644 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1645 			ext4_msg(sb, KERN_ERR, "old and new quota "
1646 					"format mixing");
1647 			return 0;
1648 		}
1649 
1650 		if (!sbi->s_jquota_fmt) {
1651 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1652 					"not specified");
1653 			return 0;
1654 		}
1655 	} else {
1656 		if (sbi->s_jquota_fmt) {
1657 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1658 					"specified with no journaling "
1659 					"enabled");
1660 			return 0;
1661 		}
1662 	}
1663 #endif
1664 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1665 		int blocksize =
1666 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1667 
1668 		if (blocksize < PAGE_CACHE_SIZE) {
1669 			ext4_msg(sb, KERN_ERR, "can't mount with "
1670 				 "dioread_nolock if block size != PAGE_SIZE");
1671 			return 0;
1672 		}
1673 	}
1674 	return 1;
1675 }
1676 
1677 static inline void ext4_show_quota_options(struct seq_file *seq,
1678 					   struct super_block *sb)
1679 {
1680 #if defined(CONFIG_QUOTA)
1681 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1682 
1683 	if (sbi->s_jquota_fmt) {
1684 		char *fmtname = "";
1685 
1686 		switch (sbi->s_jquota_fmt) {
1687 		case QFMT_VFS_OLD:
1688 			fmtname = "vfsold";
1689 			break;
1690 		case QFMT_VFS_V0:
1691 			fmtname = "vfsv0";
1692 			break;
1693 		case QFMT_VFS_V1:
1694 			fmtname = "vfsv1";
1695 			break;
1696 		}
1697 		seq_printf(seq, ",jqfmt=%s", fmtname);
1698 	}
1699 
1700 	if (sbi->s_qf_names[USRQUOTA])
1701 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1702 
1703 	if (sbi->s_qf_names[GRPQUOTA])
1704 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1705 
1706 	if (test_opt(sb, USRQUOTA))
1707 		seq_puts(seq, ",usrquota");
1708 
1709 	if (test_opt(sb, GRPQUOTA))
1710 		seq_puts(seq, ",grpquota");
1711 #endif
1712 }
1713 
1714 static const char *token2str(int token)
1715 {
1716 	const struct match_token *t;
1717 
1718 	for (t = tokens; t->token != Opt_err; t++)
1719 		if (t->token == token && !strchr(t->pattern, '='))
1720 			break;
1721 	return t->pattern;
1722 }
1723 
1724 /*
1725  * Show an option if
1726  *  - it's set to a non-default value OR
1727  *  - if the per-sb default is different from the global default
1728  */
1729 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1730 			      int nodefs)
1731 {
1732 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1733 	struct ext4_super_block *es = sbi->s_es;
1734 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1735 	const struct mount_opts *m;
1736 	char sep = nodefs ? '\n' : ',';
1737 
1738 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1739 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1740 
1741 	if (sbi->s_sb_block != 1)
1742 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1743 
1744 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1745 		int want_set = m->flags & MOPT_SET;
1746 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1747 		    (m->flags & MOPT_CLEAR_ERR))
1748 			continue;
1749 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1750 			continue; /* skip if same as the default */
1751 		if ((want_set &&
1752 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1753 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1754 			continue; /* select Opt_noFoo vs Opt_Foo */
1755 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1756 	}
1757 
1758 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1759 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1760 		SEQ_OPTS_PRINT("resuid=%u",
1761 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1762 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1763 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1764 		SEQ_OPTS_PRINT("resgid=%u",
1765 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1766 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1767 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1768 		SEQ_OPTS_PUTS("errors=remount-ro");
1769 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1770 		SEQ_OPTS_PUTS("errors=continue");
1771 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1772 		SEQ_OPTS_PUTS("errors=panic");
1773 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1774 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1775 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1776 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1777 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1778 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1779 	if (sb->s_flags & MS_I_VERSION)
1780 		SEQ_OPTS_PUTS("i_version");
1781 	if (nodefs || sbi->s_stripe)
1782 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1783 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1784 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1785 			SEQ_OPTS_PUTS("data=journal");
1786 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1787 			SEQ_OPTS_PUTS("data=ordered");
1788 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1789 			SEQ_OPTS_PUTS("data=writeback");
1790 	}
1791 	if (nodefs ||
1792 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1793 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1794 			       sbi->s_inode_readahead_blks);
1795 
1796 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1797 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1798 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1799 	if (nodefs || sbi->s_max_dir_size_kb)
1800 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1801 
1802 	ext4_show_quota_options(seq, sb);
1803 	return 0;
1804 }
1805 
1806 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1807 {
1808 	return _ext4_show_options(seq, root->d_sb, 0);
1809 }
1810 
1811 static int options_seq_show(struct seq_file *seq, void *offset)
1812 {
1813 	struct super_block *sb = seq->private;
1814 	int rc;
1815 
1816 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1817 	rc = _ext4_show_options(seq, sb, 1);
1818 	seq_puts(seq, "\n");
1819 	return rc;
1820 }
1821 
1822 static int options_open_fs(struct inode *inode, struct file *file)
1823 {
1824 	return single_open(file, options_seq_show, PDE_DATA(inode));
1825 }
1826 
1827 static const struct file_operations ext4_seq_options_fops = {
1828 	.owner = THIS_MODULE,
1829 	.open = options_open_fs,
1830 	.read = seq_read,
1831 	.llseek = seq_lseek,
1832 	.release = single_release,
1833 };
1834 
1835 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1836 			    int read_only)
1837 {
1838 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1839 	int res = 0;
1840 
1841 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1842 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1843 			 "forcing read-only mode");
1844 		res = MS_RDONLY;
1845 	}
1846 	if (read_only)
1847 		goto done;
1848 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1849 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1850 			 "running e2fsck is recommended");
1851 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1852 		ext4_msg(sb, KERN_WARNING,
1853 			 "warning: mounting fs with errors, "
1854 			 "running e2fsck is recommended");
1855 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1856 		 le16_to_cpu(es->s_mnt_count) >=
1857 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1858 		ext4_msg(sb, KERN_WARNING,
1859 			 "warning: maximal mount count reached, "
1860 			 "running e2fsck is recommended");
1861 	else if (le32_to_cpu(es->s_checkinterval) &&
1862 		(le32_to_cpu(es->s_lastcheck) +
1863 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1864 		ext4_msg(sb, KERN_WARNING,
1865 			 "warning: checktime reached, "
1866 			 "running e2fsck is recommended");
1867 	if (!sbi->s_journal)
1868 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1869 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1870 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1871 	le16_add_cpu(&es->s_mnt_count, 1);
1872 	es->s_mtime = cpu_to_le32(get_seconds());
1873 	ext4_update_dynamic_rev(sb);
1874 	if (sbi->s_journal)
1875 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1876 
1877 	ext4_commit_super(sb, 1);
1878 done:
1879 	if (test_opt(sb, DEBUG))
1880 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1881 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1882 			sb->s_blocksize,
1883 			sbi->s_groups_count,
1884 			EXT4_BLOCKS_PER_GROUP(sb),
1885 			EXT4_INODES_PER_GROUP(sb),
1886 			sbi->s_mount_opt, sbi->s_mount_opt2);
1887 
1888 	cleancache_init_fs(sb);
1889 	return res;
1890 }
1891 
1892 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1893 {
1894 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1895 	struct flex_groups *new_groups;
1896 	int size;
1897 
1898 	if (!sbi->s_log_groups_per_flex)
1899 		return 0;
1900 
1901 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
1902 	if (size <= sbi->s_flex_groups_allocated)
1903 		return 0;
1904 
1905 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1906 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1907 	if (!new_groups) {
1908 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1909 			 size / (int) sizeof(struct flex_groups));
1910 		return -ENOMEM;
1911 	}
1912 
1913 	if (sbi->s_flex_groups) {
1914 		memcpy(new_groups, sbi->s_flex_groups,
1915 		       (sbi->s_flex_groups_allocated *
1916 			sizeof(struct flex_groups)));
1917 		ext4_kvfree(sbi->s_flex_groups);
1918 	}
1919 	sbi->s_flex_groups = new_groups;
1920 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1921 	return 0;
1922 }
1923 
1924 static int ext4_fill_flex_info(struct super_block *sb)
1925 {
1926 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1927 	struct ext4_group_desc *gdp = NULL;
1928 	ext4_group_t flex_group;
1929 	int i, err;
1930 
1931 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1932 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1933 		sbi->s_log_groups_per_flex = 0;
1934 		return 1;
1935 	}
1936 
1937 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1938 	if (err)
1939 		goto failed;
1940 
1941 	for (i = 0; i < sbi->s_groups_count; i++) {
1942 		gdp = ext4_get_group_desc(sb, i, NULL);
1943 
1944 		flex_group = ext4_flex_group(sbi, i);
1945 		atomic_add(ext4_free_inodes_count(sb, gdp),
1946 			   &sbi->s_flex_groups[flex_group].free_inodes);
1947 		atomic64_add(ext4_free_group_clusters(sb, gdp),
1948 			     &sbi->s_flex_groups[flex_group].free_clusters);
1949 		atomic_add(ext4_used_dirs_count(sb, gdp),
1950 			   &sbi->s_flex_groups[flex_group].used_dirs);
1951 	}
1952 
1953 	return 1;
1954 failed:
1955 	return 0;
1956 }
1957 
1958 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1959 				   struct ext4_group_desc *gdp)
1960 {
1961 	int offset;
1962 	__u16 crc = 0;
1963 	__le32 le_group = cpu_to_le32(block_group);
1964 
1965 	if ((sbi->s_es->s_feature_ro_compat &
1966 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1967 		/* Use new metadata_csum algorithm */
1968 		__le16 save_csum;
1969 		__u32 csum32;
1970 
1971 		save_csum = gdp->bg_checksum;
1972 		gdp->bg_checksum = 0;
1973 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
1974 				     sizeof(le_group));
1975 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
1976 				     sbi->s_desc_size);
1977 		gdp->bg_checksum = save_csum;
1978 
1979 		crc = csum32 & 0xFFFF;
1980 		goto out;
1981 	}
1982 
1983 	/* old crc16 code */
1984 	offset = offsetof(struct ext4_group_desc, bg_checksum);
1985 
1986 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1987 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1988 	crc = crc16(crc, (__u8 *)gdp, offset);
1989 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
1990 	/* for checksum of struct ext4_group_desc do the rest...*/
1991 	if ((sbi->s_es->s_feature_incompat &
1992 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1993 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
1994 		crc = crc16(crc, (__u8 *)gdp + offset,
1995 			    le16_to_cpu(sbi->s_es->s_desc_size) -
1996 				offset);
1997 
1998 out:
1999 	return cpu_to_le16(crc);
2000 }
2001 
2002 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2003 				struct ext4_group_desc *gdp)
2004 {
2005 	if (ext4_has_group_desc_csum(sb) &&
2006 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2007 						      block_group, gdp)))
2008 		return 0;
2009 
2010 	return 1;
2011 }
2012 
2013 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2014 			      struct ext4_group_desc *gdp)
2015 {
2016 	if (!ext4_has_group_desc_csum(sb))
2017 		return;
2018 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2019 }
2020 
2021 /* Called at mount-time, super-block is locked */
2022 static int ext4_check_descriptors(struct super_block *sb,
2023 				  ext4_group_t *first_not_zeroed)
2024 {
2025 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2026 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2027 	ext4_fsblk_t last_block;
2028 	ext4_fsblk_t block_bitmap;
2029 	ext4_fsblk_t inode_bitmap;
2030 	ext4_fsblk_t inode_table;
2031 	int flexbg_flag = 0;
2032 	ext4_group_t i, grp = sbi->s_groups_count;
2033 
2034 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2035 		flexbg_flag = 1;
2036 
2037 	ext4_debug("Checking group descriptors");
2038 
2039 	for (i = 0; i < sbi->s_groups_count; i++) {
2040 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2041 
2042 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2043 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2044 		else
2045 			last_block = first_block +
2046 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2047 
2048 		if ((grp == sbi->s_groups_count) &&
2049 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2050 			grp = i;
2051 
2052 		block_bitmap = ext4_block_bitmap(sb, gdp);
2053 		if (block_bitmap < first_block || block_bitmap > last_block) {
2054 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2055 			       "Block bitmap for group %u not in group "
2056 			       "(block %llu)!", i, block_bitmap);
2057 			return 0;
2058 		}
2059 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2060 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2061 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2062 			       "Inode bitmap for group %u not in group "
2063 			       "(block %llu)!", i, inode_bitmap);
2064 			return 0;
2065 		}
2066 		inode_table = ext4_inode_table(sb, gdp);
2067 		if (inode_table < first_block ||
2068 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2069 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2070 			       "Inode table for group %u not in group "
2071 			       "(block %llu)!", i, inode_table);
2072 			return 0;
2073 		}
2074 		ext4_lock_group(sb, i);
2075 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2076 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2077 				 "Checksum for group %u failed (%u!=%u)",
2078 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2079 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2080 			if (!(sb->s_flags & MS_RDONLY)) {
2081 				ext4_unlock_group(sb, i);
2082 				return 0;
2083 			}
2084 		}
2085 		ext4_unlock_group(sb, i);
2086 		if (!flexbg_flag)
2087 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2088 	}
2089 	if (NULL != first_not_zeroed)
2090 		*first_not_zeroed = grp;
2091 
2092 	ext4_free_blocks_count_set(sbi->s_es,
2093 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2094 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2095 	return 1;
2096 }
2097 
2098 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2099  * the superblock) which were deleted from all directories, but held open by
2100  * a process at the time of a crash.  We walk the list and try to delete these
2101  * inodes at recovery time (only with a read-write filesystem).
2102  *
2103  * In order to keep the orphan inode chain consistent during traversal (in
2104  * case of crash during recovery), we link each inode into the superblock
2105  * orphan list_head and handle it the same way as an inode deletion during
2106  * normal operation (which journals the operations for us).
2107  *
2108  * We only do an iget() and an iput() on each inode, which is very safe if we
2109  * accidentally point at an in-use or already deleted inode.  The worst that
2110  * can happen in this case is that we get a "bit already cleared" message from
2111  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2112  * e2fsck was run on this filesystem, and it must have already done the orphan
2113  * inode cleanup for us, so we can safely abort without any further action.
2114  */
2115 static void ext4_orphan_cleanup(struct super_block *sb,
2116 				struct ext4_super_block *es)
2117 {
2118 	unsigned int s_flags = sb->s_flags;
2119 	int nr_orphans = 0, nr_truncates = 0;
2120 #ifdef CONFIG_QUOTA
2121 	int i;
2122 #endif
2123 	if (!es->s_last_orphan) {
2124 		jbd_debug(4, "no orphan inodes to clean up\n");
2125 		return;
2126 	}
2127 
2128 	if (bdev_read_only(sb->s_bdev)) {
2129 		ext4_msg(sb, KERN_ERR, "write access "
2130 			"unavailable, skipping orphan cleanup");
2131 		return;
2132 	}
2133 
2134 	/* Check if feature set would not allow a r/w mount */
2135 	if (!ext4_feature_set_ok(sb, 0)) {
2136 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2137 			 "unknown ROCOMPAT features");
2138 		return;
2139 	}
2140 
2141 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2142 		/* don't clear list on RO mount w/ errors */
2143 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2144 			jbd_debug(1, "Errors on filesystem, "
2145 				  "clearing orphan list.\n");
2146 			es->s_last_orphan = 0;
2147 		}
2148 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2149 		return;
2150 	}
2151 
2152 	if (s_flags & MS_RDONLY) {
2153 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2154 		sb->s_flags &= ~MS_RDONLY;
2155 	}
2156 #ifdef CONFIG_QUOTA
2157 	/* Needed for iput() to work correctly and not trash data */
2158 	sb->s_flags |= MS_ACTIVE;
2159 	/* Turn on quotas so that they are updated correctly */
2160 	for (i = 0; i < MAXQUOTAS; i++) {
2161 		if (EXT4_SB(sb)->s_qf_names[i]) {
2162 			int ret = ext4_quota_on_mount(sb, i);
2163 			if (ret < 0)
2164 				ext4_msg(sb, KERN_ERR,
2165 					"Cannot turn on journaled "
2166 					"quota: error %d", ret);
2167 		}
2168 	}
2169 #endif
2170 
2171 	while (es->s_last_orphan) {
2172 		struct inode *inode;
2173 
2174 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2175 		if (IS_ERR(inode)) {
2176 			es->s_last_orphan = 0;
2177 			break;
2178 		}
2179 
2180 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2181 		dquot_initialize(inode);
2182 		if (inode->i_nlink) {
2183 			if (test_opt(sb, DEBUG))
2184 				ext4_msg(sb, KERN_DEBUG,
2185 					"%s: truncating inode %lu to %lld bytes",
2186 					__func__, inode->i_ino, inode->i_size);
2187 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2188 				  inode->i_ino, inode->i_size);
2189 			mutex_lock(&inode->i_mutex);
2190 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2191 			ext4_truncate(inode);
2192 			mutex_unlock(&inode->i_mutex);
2193 			nr_truncates++;
2194 		} else {
2195 			if (test_opt(sb, DEBUG))
2196 				ext4_msg(sb, KERN_DEBUG,
2197 					"%s: deleting unreferenced inode %lu",
2198 					__func__, inode->i_ino);
2199 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2200 				  inode->i_ino);
2201 			nr_orphans++;
2202 		}
2203 		iput(inode);  /* The delete magic happens here! */
2204 	}
2205 
2206 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2207 
2208 	if (nr_orphans)
2209 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2210 		       PLURAL(nr_orphans));
2211 	if (nr_truncates)
2212 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2213 		       PLURAL(nr_truncates));
2214 #ifdef CONFIG_QUOTA
2215 	/* Turn quotas off */
2216 	for (i = 0; i < MAXQUOTAS; i++) {
2217 		if (sb_dqopt(sb)->files[i])
2218 			dquot_quota_off(sb, i);
2219 	}
2220 #endif
2221 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2222 }
2223 
2224 /*
2225  * Maximal extent format file size.
2226  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2227  * extent format containers, within a sector_t, and within i_blocks
2228  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2229  * so that won't be a limiting factor.
2230  *
2231  * However there is other limiting factor. We do store extents in the form
2232  * of starting block and length, hence the resulting length of the extent
2233  * covering maximum file size must fit into on-disk format containers as
2234  * well. Given that length is always by 1 unit bigger than max unit (because
2235  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2236  *
2237  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2238  */
2239 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2240 {
2241 	loff_t res;
2242 	loff_t upper_limit = MAX_LFS_FILESIZE;
2243 
2244 	/* small i_blocks in vfs inode? */
2245 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2246 		/*
2247 		 * CONFIG_LBDAF is not enabled implies the inode
2248 		 * i_block represent total blocks in 512 bytes
2249 		 * 32 == size of vfs inode i_blocks * 8
2250 		 */
2251 		upper_limit = (1LL << 32) - 1;
2252 
2253 		/* total blocks in file system block size */
2254 		upper_limit >>= (blkbits - 9);
2255 		upper_limit <<= blkbits;
2256 	}
2257 
2258 	/*
2259 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2260 	 * by one fs block, so ee_len can cover the extent of maximum file
2261 	 * size
2262 	 */
2263 	res = (1LL << 32) - 1;
2264 	res <<= blkbits;
2265 
2266 	/* Sanity check against vm- & vfs- imposed limits */
2267 	if (res > upper_limit)
2268 		res = upper_limit;
2269 
2270 	return res;
2271 }
2272 
2273 /*
2274  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2275  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2276  * We need to be 1 filesystem block less than the 2^48 sector limit.
2277  */
2278 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2279 {
2280 	loff_t res = EXT4_NDIR_BLOCKS;
2281 	int meta_blocks;
2282 	loff_t upper_limit;
2283 	/* This is calculated to be the largest file size for a dense, block
2284 	 * mapped file such that the file's total number of 512-byte sectors,
2285 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2286 	 *
2287 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2288 	 * number of 512-byte sectors of the file.
2289 	 */
2290 
2291 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2292 		/*
2293 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2294 		 * the inode i_block field represents total file blocks in
2295 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2296 		 */
2297 		upper_limit = (1LL << 32) - 1;
2298 
2299 		/* total blocks in file system block size */
2300 		upper_limit >>= (bits - 9);
2301 
2302 	} else {
2303 		/*
2304 		 * We use 48 bit ext4_inode i_blocks
2305 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2306 		 * represent total number of blocks in
2307 		 * file system block size
2308 		 */
2309 		upper_limit = (1LL << 48) - 1;
2310 
2311 	}
2312 
2313 	/* indirect blocks */
2314 	meta_blocks = 1;
2315 	/* double indirect blocks */
2316 	meta_blocks += 1 + (1LL << (bits-2));
2317 	/* tripple indirect blocks */
2318 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2319 
2320 	upper_limit -= meta_blocks;
2321 	upper_limit <<= bits;
2322 
2323 	res += 1LL << (bits-2);
2324 	res += 1LL << (2*(bits-2));
2325 	res += 1LL << (3*(bits-2));
2326 	res <<= bits;
2327 	if (res > upper_limit)
2328 		res = upper_limit;
2329 
2330 	if (res > MAX_LFS_FILESIZE)
2331 		res = MAX_LFS_FILESIZE;
2332 
2333 	return res;
2334 }
2335 
2336 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2337 				   ext4_fsblk_t logical_sb_block, int nr)
2338 {
2339 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2340 	ext4_group_t bg, first_meta_bg;
2341 	int has_super = 0;
2342 
2343 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2344 
2345 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2346 	    nr < first_meta_bg)
2347 		return logical_sb_block + nr + 1;
2348 	bg = sbi->s_desc_per_block * nr;
2349 	if (ext4_bg_has_super(sb, bg))
2350 		has_super = 1;
2351 
2352 	return (has_super + ext4_group_first_block_no(sb, bg));
2353 }
2354 
2355 /**
2356  * ext4_get_stripe_size: Get the stripe size.
2357  * @sbi: In memory super block info
2358  *
2359  * If we have specified it via mount option, then
2360  * use the mount option value. If the value specified at mount time is
2361  * greater than the blocks per group use the super block value.
2362  * If the super block value is greater than blocks per group return 0.
2363  * Allocator needs it be less than blocks per group.
2364  *
2365  */
2366 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2367 {
2368 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2369 	unsigned long stripe_width =
2370 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2371 	int ret;
2372 
2373 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2374 		ret = sbi->s_stripe;
2375 	else if (stripe_width <= sbi->s_blocks_per_group)
2376 		ret = stripe_width;
2377 	else if (stride <= sbi->s_blocks_per_group)
2378 		ret = stride;
2379 	else
2380 		ret = 0;
2381 
2382 	/*
2383 	 * If the stripe width is 1, this makes no sense and
2384 	 * we set it to 0 to turn off stripe handling code.
2385 	 */
2386 	if (ret <= 1)
2387 		ret = 0;
2388 
2389 	return ret;
2390 }
2391 
2392 /* sysfs supprt */
2393 
2394 struct ext4_attr {
2395 	struct attribute attr;
2396 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2397 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2398 			 const char *, size_t);
2399 	union {
2400 		int offset;
2401 		int deprecated_val;
2402 	} u;
2403 };
2404 
2405 static int parse_strtoull(const char *buf,
2406 		unsigned long long max, unsigned long long *value)
2407 {
2408 	int ret;
2409 
2410 	ret = kstrtoull(skip_spaces(buf), 0, value);
2411 	if (!ret && *value > max)
2412 		ret = -EINVAL;
2413 	return ret;
2414 }
2415 
2416 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2417 					      struct ext4_sb_info *sbi,
2418 					      char *buf)
2419 {
2420 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2421 		(s64) EXT4_C2B(sbi,
2422 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2423 }
2424 
2425 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2426 					 struct ext4_sb_info *sbi, char *buf)
2427 {
2428 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2429 
2430 	if (!sb->s_bdev->bd_part)
2431 		return snprintf(buf, PAGE_SIZE, "0\n");
2432 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2433 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2434 			 sbi->s_sectors_written_start) >> 1);
2435 }
2436 
2437 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2438 					  struct ext4_sb_info *sbi, char *buf)
2439 {
2440 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2441 
2442 	if (!sb->s_bdev->bd_part)
2443 		return snprintf(buf, PAGE_SIZE, "0\n");
2444 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2445 			(unsigned long long)(sbi->s_kbytes_written +
2446 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2447 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2448 }
2449 
2450 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2451 					  struct ext4_sb_info *sbi,
2452 					  const char *buf, size_t count)
2453 {
2454 	unsigned long t;
2455 	int ret;
2456 
2457 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2458 	if (ret)
2459 		return ret;
2460 
2461 	if (t && (!is_power_of_2(t) || t > 0x40000000))
2462 		return -EINVAL;
2463 
2464 	sbi->s_inode_readahead_blks = t;
2465 	return count;
2466 }
2467 
2468 static ssize_t sbi_ui_show(struct ext4_attr *a,
2469 			   struct ext4_sb_info *sbi, char *buf)
2470 {
2471 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2472 
2473 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2474 }
2475 
2476 static ssize_t sbi_ui_store(struct ext4_attr *a,
2477 			    struct ext4_sb_info *sbi,
2478 			    const char *buf, size_t count)
2479 {
2480 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2481 	unsigned long t;
2482 	int ret;
2483 
2484 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2485 	if (ret)
2486 		return ret;
2487 	*ui = t;
2488 	return count;
2489 }
2490 
2491 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2492 				  struct ext4_sb_info *sbi, char *buf)
2493 {
2494 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2495 		(unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2496 }
2497 
2498 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2499 				   struct ext4_sb_info *sbi,
2500 				   const char *buf, size_t count)
2501 {
2502 	unsigned long long val;
2503 	int ret;
2504 
2505 	if (parse_strtoull(buf, -1ULL, &val))
2506 		return -EINVAL;
2507 	ret = ext4_reserve_clusters(sbi, val);
2508 
2509 	return ret ? ret : count;
2510 }
2511 
2512 static ssize_t trigger_test_error(struct ext4_attr *a,
2513 				  struct ext4_sb_info *sbi,
2514 				  const char *buf, size_t count)
2515 {
2516 	int len = count;
2517 
2518 	if (!capable(CAP_SYS_ADMIN))
2519 		return -EPERM;
2520 
2521 	if (len && buf[len-1] == '\n')
2522 		len--;
2523 
2524 	if (len)
2525 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2526 	return count;
2527 }
2528 
2529 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2530 				   struct ext4_sb_info *sbi, char *buf)
2531 {
2532 	return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2533 }
2534 
2535 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2536 static struct ext4_attr ext4_attr_##_name = {			\
2537 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2538 	.show	= _show,					\
2539 	.store	= _store,					\
2540 	.u = {							\
2541 		.offset = offsetof(struct ext4_sb_info, _elname),\
2542 	},							\
2543 }
2544 #define EXT4_ATTR(name, mode, show, store) \
2545 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2546 
2547 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2548 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2549 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2550 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2551 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2552 #define ATTR_LIST(name) &ext4_attr_##name.attr
2553 #define EXT4_DEPRECATED_ATTR(_name, _val)	\
2554 static struct ext4_attr ext4_attr_##_name = {			\
2555 	.attr = {.name = __stringify(_name), .mode = 0444 },	\
2556 	.show	= sbi_deprecated_show,				\
2557 	.u = {							\
2558 		.deprecated_val = _val,				\
2559 	},							\
2560 }
2561 
2562 EXT4_RO_ATTR(delayed_allocation_blocks);
2563 EXT4_RO_ATTR(session_write_kbytes);
2564 EXT4_RO_ATTR(lifetime_write_kbytes);
2565 EXT4_RW_ATTR(reserved_clusters);
2566 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2567 		 inode_readahead_blks_store, s_inode_readahead_blks);
2568 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2569 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2570 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2571 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2572 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2573 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2574 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2575 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2576 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2577 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2578 
2579 static struct attribute *ext4_attrs[] = {
2580 	ATTR_LIST(delayed_allocation_blocks),
2581 	ATTR_LIST(session_write_kbytes),
2582 	ATTR_LIST(lifetime_write_kbytes),
2583 	ATTR_LIST(reserved_clusters),
2584 	ATTR_LIST(inode_readahead_blks),
2585 	ATTR_LIST(inode_goal),
2586 	ATTR_LIST(mb_stats),
2587 	ATTR_LIST(mb_max_to_scan),
2588 	ATTR_LIST(mb_min_to_scan),
2589 	ATTR_LIST(mb_order2_req),
2590 	ATTR_LIST(mb_stream_req),
2591 	ATTR_LIST(mb_group_prealloc),
2592 	ATTR_LIST(max_writeback_mb_bump),
2593 	ATTR_LIST(extent_max_zeroout_kb),
2594 	ATTR_LIST(trigger_fs_error),
2595 	NULL,
2596 };
2597 
2598 /* Features this copy of ext4 supports */
2599 EXT4_INFO_ATTR(lazy_itable_init);
2600 EXT4_INFO_ATTR(batched_discard);
2601 EXT4_INFO_ATTR(meta_bg_resize);
2602 
2603 static struct attribute *ext4_feat_attrs[] = {
2604 	ATTR_LIST(lazy_itable_init),
2605 	ATTR_LIST(batched_discard),
2606 	ATTR_LIST(meta_bg_resize),
2607 	NULL,
2608 };
2609 
2610 static ssize_t ext4_attr_show(struct kobject *kobj,
2611 			      struct attribute *attr, char *buf)
2612 {
2613 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2614 						s_kobj);
2615 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2616 
2617 	return a->show ? a->show(a, sbi, buf) : 0;
2618 }
2619 
2620 static ssize_t ext4_attr_store(struct kobject *kobj,
2621 			       struct attribute *attr,
2622 			       const char *buf, size_t len)
2623 {
2624 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2625 						s_kobj);
2626 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2627 
2628 	return a->store ? a->store(a, sbi, buf, len) : 0;
2629 }
2630 
2631 static void ext4_sb_release(struct kobject *kobj)
2632 {
2633 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2634 						s_kobj);
2635 	complete(&sbi->s_kobj_unregister);
2636 }
2637 
2638 static const struct sysfs_ops ext4_attr_ops = {
2639 	.show	= ext4_attr_show,
2640 	.store	= ext4_attr_store,
2641 };
2642 
2643 static struct kobj_type ext4_ktype = {
2644 	.default_attrs	= ext4_attrs,
2645 	.sysfs_ops	= &ext4_attr_ops,
2646 	.release	= ext4_sb_release,
2647 };
2648 
2649 static void ext4_feat_release(struct kobject *kobj)
2650 {
2651 	complete(&ext4_feat->f_kobj_unregister);
2652 }
2653 
2654 static struct kobj_type ext4_feat_ktype = {
2655 	.default_attrs	= ext4_feat_attrs,
2656 	.sysfs_ops	= &ext4_attr_ops,
2657 	.release	= ext4_feat_release,
2658 };
2659 
2660 /*
2661  * Check whether this filesystem can be mounted based on
2662  * the features present and the RDONLY/RDWR mount requested.
2663  * Returns 1 if this filesystem can be mounted as requested,
2664  * 0 if it cannot be.
2665  */
2666 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2667 {
2668 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2669 		ext4_msg(sb, KERN_ERR,
2670 			"Couldn't mount because of "
2671 			"unsupported optional features (%x)",
2672 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2673 			~EXT4_FEATURE_INCOMPAT_SUPP));
2674 		return 0;
2675 	}
2676 
2677 	if (readonly)
2678 		return 1;
2679 
2680 	/* Check that feature set is OK for a read-write mount */
2681 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2682 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2683 			 "unsupported optional features (%x)",
2684 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2685 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2686 		return 0;
2687 	}
2688 	/*
2689 	 * Large file size enabled file system can only be mounted
2690 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2691 	 */
2692 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2693 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2694 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2695 				 "cannot be mounted RDWR without "
2696 				 "CONFIG_LBDAF");
2697 			return 0;
2698 		}
2699 	}
2700 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2701 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2702 		ext4_msg(sb, KERN_ERR,
2703 			 "Can't support bigalloc feature without "
2704 			 "extents feature\n");
2705 		return 0;
2706 	}
2707 
2708 #ifndef CONFIG_QUOTA
2709 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2710 	    !readonly) {
2711 		ext4_msg(sb, KERN_ERR,
2712 			 "Filesystem with quota feature cannot be mounted RDWR "
2713 			 "without CONFIG_QUOTA");
2714 		return 0;
2715 	}
2716 #endif  /* CONFIG_QUOTA */
2717 	return 1;
2718 }
2719 
2720 /*
2721  * This function is called once a day if we have errors logged
2722  * on the file system
2723  */
2724 static void print_daily_error_info(unsigned long arg)
2725 {
2726 	struct super_block *sb = (struct super_block *) arg;
2727 	struct ext4_sb_info *sbi;
2728 	struct ext4_super_block *es;
2729 
2730 	sbi = EXT4_SB(sb);
2731 	es = sbi->s_es;
2732 
2733 	if (es->s_error_count)
2734 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2735 			 le32_to_cpu(es->s_error_count));
2736 	if (es->s_first_error_time) {
2737 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2738 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2739 		       (int) sizeof(es->s_first_error_func),
2740 		       es->s_first_error_func,
2741 		       le32_to_cpu(es->s_first_error_line));
2742 		if (es->s_first_error_ino)
2743 			printk(": inode %u",
2744 			       le32_to_cpu(es->s_first_error_ino));
2745 		if (es->s_first_error_block)
2746 			printk(": block %llu", (unsigned long long)
2747 			       le64_to_cpu(es->s_first_error_block));
2748 		printk("\n");
2749 	}
2750 	if (es->s_last_error_time) {
2751 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2752 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2753 		       (int) sizeof(es->s_last_error_func),
2754 		       es->s_last_error_func,
2755 		       le32_to_cpu(es->s_last_error_line));
2756 		if (es->s_last_error_ino)
2757 			printk(": inode %u",
2758 			       le32_to_cpu(es->s_last_error_ino));
2759 		if (es->s_last_error_block)
2760 			printk(": block %llu", (unsigned long long)
2761 			       le64_to_cpu(es->s_last_error_block));
2762 		printk("\n");
2763 	}
2764 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2765 }
2766 
2767 /* Find next suitable group and run ext4_init_inode_table */
2768 static int ext4_run_li_request(struct ext4_li_request *elr)
2769 {
2770 	struct ext4_group_desc *gdp = NULL;
2771 	ext4_group_t group, ngroups;
2772 	struct super_block *sb;
2773 	unsigned long timeout = 0;
2774 	int ret = 0;
2775 
2776 	sb = elr->lr_super;
2777 	ngroups = EXT4_SB(sb)->s_groups_count;
2778 
2779 	sb_start_write(sb);
2780 	for (group = elr->lr_next_group; group < ngroups; group++) {
2781 		gdp = ext4_get_group_desc(sb, group, NULL);
2782 		if (!gdp) {
2783 			ret = 1;
2784 			break;
2785 		}
2786 
2787 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2788 			break;
2789 	}
2790 
2791 	if (group >= ngroups)
2792 		ret = 1;
2793 
2794 	if (!ret) {
2795 		timeout = jiffies;
2796 		ret = ext4_init_inode_table(sb, group,
2797 					    elr->lr_timeout ? 0 : 1);
2798 		if (elr->lr_timeout == 0) {
2799 			timeout = (jiffies - timeout) *
2800 				  elr->lr_sbi->s_li_wait_mult;
2801 			elr->lr_timeout = timeout;
2802 		}
2803 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2804 		elr->lr_next_group = group + 1;
2805 	}
2806 	sb_end_write(sb);
2807 
2808 	return ret;
2809 }
2810 
2811 /*
2812  * Remove lr_request from the list_request and free the
2813  * request structure. Should be called with li_list_mtx held
2814  */
2815 static void ext4_remove_li_request(struct ext4_li_request *elr)
2816 {
2817 	struct ext4_sb_info *sbi;
2818 
2819 	if (!elr)
2820 		return;
2821 
2822 	sbi = elr->lr_sbi;
2823 
2824 	list_del(&elr->lr_request);
2825 	sbi->s_li_request = NULL;
2826 	kfree(elr);
2827 }
2828 
2829 static void ext4_unregister_li_request(struct super_block *sb)
2830 {
2831 	mutex_lock(&ext4_li_mtx);
2832 	if (!ext4_li_info) {
2833 		mutex_unlock(&ext4_li_mtx);
2834 		return;
2835 	}
2836 
2837 	mutex_lock(&ext4_li_info->li_list_mtx);
2838 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2839 	mutex_unlock(&ext4_li_info->li_list_mtx);
2840 	mutex_unlock(&ext4_li_mtx);
2841 }
2842 
2843 static struct task_struct *ext4_lazyinit_task;
2844 
2845 /*
2846  * This is the function where ext4lazyinit thread lives. It walks
2847  * through the request list searching for next scheduled filesystem.
2848  * When such a fs is found, run the lazy initialization request
2849  * (ext4_rn_li_request) and keep track of the time spend in this
2850  * function. Based on that time we compute next schedule time of
2851  * the request. When walking through the list is complete, compute
2852  * next waking time and put itself into sleep.
2853  */
2854 static int ext4_lazyinit_thread(void *arg)
2855 {
2856 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2857 	struct list_head *pos, *n;
2858 	struct ext4_li_request *elr;
2859 	unsigned long next_wakeup, cur;
2860 
2861 	BUG_ON(NULL == eli);
2862 
2863 cont_thread:
2864 	while (true) {
2865 		next_wakeup = MAX_JIFFY_OFFSET;
2866 
2867 		mutex_lock(&eli->li_list_mtx);
2868 		if (list_empty(&eli->li_request_list)) {
2869 			mutex_unlock(&eli->li_list_mtx);
2870 			goto exit_thread;
2871 		}
2872 
2873 		list_for_each_safe(pos, n, &eli->li_request_list) {
2874 			elr = list_entry(pos, struct ext4_li_request,
2875 					 lr_request);
2876 
2877 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2878 				if (ext4_run_li_request(elr) != 0) {
2879 					/* error, remove the lazy_init job */
2880 					ext4_remove_li_request(elr);
2881 					continue;
2882 				}
2883 			}
2884 
2885 			if (time_before(elr->lr_next_sched, next_wakeup))
2886 				next_wakeup = elr->lr_next_sched;
2887 		}
2888 		mutex_unlock(&eli->li_list_mtx);
2889 
2890 		try_to_freeze();
2891 
2892 		cur = jiffies;
2893 		if ((time_after_eq(cur, next_wakeup)) ||
2894 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2895 			cond_resched();
2896 			continue;
2897 		}
2898 
2899 		schedule_timeout_interruptible(next_wakeup - cur);
2900 
2901 		if (kthread_should_stop()) {
2902 			ext4_clear_request_list();
2903 			goto exit_thread;
2904 		}
2905 	}
2906 
2907 exit_thread:
2908 	/*
2909 	 * It looks like the request list is empty, but we need
2910 	 * to check it under the li_list_mtx lock, to prevent any
2911 	 * additions into it, and of course we should lock ext4_li_mtx
2912 	 * to atomically free the list and ext4_li_info, because at
2913 	 * this point another ext4 filesystem could be registering
2914 	 * new one.
2915 	 */
2916 	mutex_lock(&ext4_li_mtx);
2917 	mutex_lock(&eli->li_list_mtx);
2918 	if (!list_empty(&eli->li_request_list)) {
2919 		mutex_unlock(&eli->li_list_mtx);
2920 		mutex_unlock(&ext4_li_mtx);
2921 		goto cont_thread;
2922 	}
2923 	mutex_unlock(&eli->li_list_mtx);
2924 	kfree(ext4_li_info);
2925 	ext4_li_info = NULL;
2926 	mutex_unlock(&ext4_li_mtx);
2927 
2928 	return 0;
2929 }
2930 
2931 static void ext4_clear_request_list(void)
2932 {
2933 	struct list_head *pos, *n;
2934 	struct ext4_li_request *elr;
2935 
2936 	mutex_lock(&ext4_li_info->li_list_mtx);
2937 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2938 		elr = list_entry(pos, struct ext4_li_request,
2939 				 lr_request);
2940 		ext4_remove_li_request(elr);
2941 	}
2942 	mutex_unlock(&ext4_li_info->li_list_mtx);
2943 }
2944 
2945 static int ext4_run_lazyinit_thread(void)
2946 {
2947 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2948 					 ext4_li_info, "ext4lazyinit");
2949 	if (IS_ERR(ext4_lazyinit_task)) {
2950 		int err = PTR_ERR(ext4_lazyinit_task);
2951 		ext4_clear_request_list();
2952 		kfree(ext4_li_info);
2953 		ext4_li_info = NULL;
2954 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2955 				 "initialization thread\n",
2956 				 err);
2957 		return err;
2958 	}
2959 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2960 	return 0;
2961 }
2962 
2963 /*
2964  * Check whether it make sense to run itable init. thread or not.
2965  * If there is at least one uninitialized inode table, return
2966  * corresponding group number, else the loop goes through all
2967  * groups and return total number of groups.
2968  */
2969 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2970 {
2971 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2972 	struct ext4_group_desc *gdp = NULL;
2973 
2974 	for (group = 0; group < ngroups; group++) {
2975 		gdp = ext4_get_group_desc(sb, group, NULL);
2976 		if (!gdp)
2977 			continue;
2978 
2979 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2980 			break;
2981 	}
2982 
2983 	return group;
2984 }
2985 
2986 static int ext4_li_info_new(void)
2987 {
2988 	struct ext4_lazy_init *eli = NULL;
2989 
2990 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2991 	if (!eli)
2992 		return -ENOMEM;
2993 
2994 	INIT_LIST_HEAD(&eli->li_request_list);
2995 	mutex_init(&eli->li_list_mtx);
2996 
2997 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2998 
2999 	ext4_li_info = eli;
3000 
3001 	return 0;
3002 }
3003 
3004 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3005 					    ext4_group_t start)
3006 {
3007 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3008 	struct ext4_li_request *elr;
3009 	unsigned long rnd;
3010 
3011 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3012 	if (!elr)
3013 		return NULL;
3014 
3015 	elr->lr_super = sb;
3016 	elr->lr_sbi = sbi;
3017 	elr->lr_next_group = start;
3018 
3019 	/*
3020 	 * Randomize first schedule time of the request to
3021 	 * spread the inode table initialization requests
3022 	 * better.
3023 	 */
3024 	get_random_bytes(&rnd, sizeof(rnd));
3025 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
3026 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3027 
3028 	return elr;
3029 }
3030 
3031 int ext4_register_li_request(struct super_block *sb,
3032 			     ext4_group_t first_not_zeroed)
3033 {
3034 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3035 	struct ext4_li_request *elr = NULL;
3036 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3037 	int ret = 0;
3038 
3039 	mutex_lock(&ext4_li_mtx);
3040 	if (sbi->s_li_request != NULL) {
3041 		/*
3042 		 * Reset timeout so it can be computed again, because
3043 		 * s_li_wait_mult might have changed.
3044 		 */
3045 		sbi->s_li_request->lr_timeout = 0;
3046 		goto out;
3047 	}
3048 
3049 	if (first_not_zeroed == ngroups ||
3050 	    (sb->s_flags & MS_RDONLY) ||
3051 	    !test_opt(sb, INIT_INODE_TABLE))
3052 		goto out;
3053 
3054 	elr = ext4_li_request_new(sb, first_not_zeroed);
3055 	if (!elr) {
3056 		ret = -ENOMEM;
3057 		goto out;
3058 	}
3059 
3060 	if (NULL == ext4_li_info) {
3061 		ret = ext4_li_info_new();
3062 		if (ret)
3063 			goto out;
3064 	}
3065 
3066 	mutex_lock(&ext4_li_info->li_list_mtx);
3067 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3068 	mutex_unlock(&ext4_li_info->li_list_mtx);
3069 
3070 	sbi->s_li_request = elr;
3071 	/*
3072 	 * set elr to NULL here since it has been inserted to
3073 	 * the request_list and the removal and free of it is
3074 	 * handled by ext4_clear_request_list from now on.
3075 	 */
3076 	elr = NULL;
3077 
3078 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3079 		ret = ext4_run_lazyinit_thread();
3080 		if (ret)
3081 			goto out;
3082 	}
3083 out:
3084 	mutex_unlock(&ext4_li_mtx);
3085 	if (ret)
3086 		kfree(elr);
3087 	return ret;
3088 }
3089 
3090 /*
3091  * We do not need to lock anything since this is called on
3092  * module unload.
3093  */
3094 static void ext4_destroy_lazyinit_thread(void)
3095 {
3096 	/*
3097 	 * If thread exited earlier
3098 	 * there's nothing to be done.
3099 	 */
3100 	if (!ext4_li_info || !ext4_lazyinit_task)
3101 		return;
3102 
3103 	kthread_stop(ext4_lazyinit_task);
3104 }
3105 
3106 static int set_journal_csum_feature_set(struct super_block *sb)
3107 {
3108 	int ret = 1;
3109 	int compat, incompat;
3110 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3111 
3112 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3113 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3114 		/* journal checksum v2 */
3115 		compat = 0;
3116 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3117 	} else {
3118 		/* journal checksum v1 */
3119 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3120 		incompat = 0;
3121 	}
3122 
3123 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3124 		ret = jbd2_journal_set_features(sbi->s_journal,
3125 				compat, 0,
3126 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3127 				incompat);
3128 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3129 		ret = jbd2_journal_set_features(sbi->s_journal,
3130 				compat, 0,
3131 				incompat);
3132 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3133 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3134 	} else {
3135 		jbd2_journal_clear_features(sbi->s_journal,
3136 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3137 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3138 				JBD2_FEATURE_INCOMPAT_CSUM_V2);
3139 	}
3140 
3141 	return ret;
3142 }
3143 
3144 /*
3145  * Note: calculating the overhead so we can be compatible with
3146  * historical BSD practice is quite difficult in the face of
3147  * clusters/bigalloc.  This is because multiple metadata blocks from
3148  * different block group can end up in the same allocation cluster.
3149  * Calculating the exact overhead in the face of clustered allocation
3150  * requires either O(all block bitmaps) in memory or O(number of block
3151  * groups**2) in time.  We will still calculate the superblock for
3152  * older file systems --- and if we come across with a bigalloc file
3153  * system with zero in s_overhead_clusters the estimate will be close to
3154  * correct especially for very large cluster sizes --- but for newer
3155  * file systems, it's better to calculate this figure once at mkfs
3156  * time, and store it in the superblock.  If the superblock value is
3157  * present (even for non-bigalloc file systems), we will use it.
3158  */
3159 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3160 			  char *buf)
3161 {
3162 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3163 	struct ext4_group_desc	*gdp;
3164 	ext4_fsblk_t		first_block, last_block, b;
3165 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3166 	int			s, j, count = 0;
3167 
3168 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3169 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3170 			sbi->s_itb_per_group + 2);
3171 
3172 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3173 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3174 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3175 	for (i = 0; i < ngroups; i++) {
3176 		gdp = ext4_get_group_desc(sb, i, NULL);
3177 		b = ext4_block_bitmap(sb, gdp);
3178 		if (b >= first_block && b <= last_block) {
3179 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3180 			count++;
3181 		}
3182 		b = ext4_inode_bitmap(sb, gdp);
3183 		if (b >= first_block && b <= last_block) {
3184 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3185 			count++;
3186 		}
3187 		b = ext4_inode_table(sb, gdp);
3188 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3189 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3190 				int c = EXT4_B2C(sbi, b - first_block);
3191 				ext4_set_bit(c, buf);
3192 				count++;
3193 			}
3194 		if (i != grp)
3195 			continue;
3196 		s = 0;
3197 		if (ext4_bg_has_super(sb, grp)) {
3198 			ext4_set_bit(s++, buf);
3199 			count++;
3200 		}
3201 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3202 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3203 			count++;
3204 		}
3205 	}
3206 	if (!count)
3207 		return 0;
3208 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3209 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3210 }
3211 
3212 /*
3213  * Compute the overhead and stash it in sbi->s_overhead
3214  */
3215 int ext4_calculate_overhead(struct super_block *sb)
3216 {
3217 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3218 	struct ext4_super_block *es = sbi->s_es;
3219 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3220 	ext4_fsblk_t overhead = 0;
3221 	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3222 
3223 	if (!buf)
3224 		return -ENOMEM;
3225 
3226 	/*
3227 	 * Compute the overhead (FS structures).  This is constant
3228 	 * for a given filesystem unless the number of block groups
3229 	 * changes so we cache the previous value until it does.
3230 	 */
3231 
3232 	/*
3233 	 * All of the blocks before first_data_block are overhead
3234 	 */
3235 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3236 
3237 	/*
3238 	 * Add the overhead found in each block group
3239 	 */
3240 	for (i = 0; i < ngroups; i++) {
3241 		int blks;
3242 
3243 		blks = count_overhead(sb, i, buf);
3244 		overhead += blks;
3245 		if (blks)
3246 			memset(buf, 0, PAGE_SIZE);
3247 		cond_resched();
3248 	}
3249 	/* Add the journal blocks as well */
3250 	if (sbi->s_journal)
3251 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3252 
3253 	sbi->s_overhead = overhead;
3254 	smp_wmb();
3255 	free_page((unsigned long) buf);
3256 	return 0;
3257 }
3258 
3259 
3260 static ext4_fsblk_t ext4_calculate_resv_clusters(struct ext4_sb_info *sbi)
3261 {
3262 	ext4_fsblk_t resv_clusters;
3263 
3264 	/*
3265 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3266 	 * This should cover the situations where we can not afford to run
3267 	 * out of space like for example punch hole, or converting
3268 	 * uninitialized extents in delalloc path. In most cases such
3269 	 * allocation would require 1, or 2 blocks, higher numbers are
3270 	 * very rare.
3271 	 */
3272 	resv_clusters = ext4_blocks_count(sbi->s_es) >> sbi->s_cluster_bits;
3273 
3274 	do_div(resv_clusters, 50);
3275 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3276 
3277 	return resv_clusters;
3278 }
3279 
3280 
3281 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3282 {
3283 	ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3284 				sbi->s_cluster_bits;
3285 
3286 	if (count >= clusters)
3287 		return -EINVAL;
3288 
3289 	atomic64_set(&sbi->s_resv_clusters, count);
3290 	return 0;
3291 }
3292 
3293 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3294 {
3295 	char *orig_data = kstrdup(data, GFP_KERNEL);
3296 	struct buffer_head *bh;
3297 	struct ext4_super_block *es = NULL;
3298 	struct ext4_sb_info *sbi;
3299 	ext4_fsblk_t block;
3300 	ext4_fsblk_t sb_block = get_sb_block(&data);
3301 	ext4_fsblk_t logical_sb_block;
3302 	unsigned long offset = 0;
3303 	unsigned long journal_devnum = 0;
3304 	unsigned long def_mount_opts;
3305 	struct inode *root;
3306 	char *cp;
3307 	const char *descr;
3308 	int ret = -ENOMEM;
3309 	int blocksize, clustersize;
3310 	unsigned int db_count;
3311 	unsigned int i;
3312 	int needs_recovery, has_huge_files, has_bigalloc;
3313 	__u64 blocks_count;
3314 	int err = 0;
3315 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3316 	ext4_group_t first_not_zeroed;
3317 
3318 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3319 	if (!sbi)
3320 		goto out_free_orig;
3321 
3322 	sbi->s_blockgroup_lock =
3323 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3324 	if (!sbi->s_blockgroup_lock) {
3325 		kfree(sbi);
3326 		goto out_free_orig;
3327 	}
3328 	sb->s_fs_info = sbi;
3329 	sbi->s_sb = sb;
3330 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3331 	sbi->s_sb_block = sb_block;
3332 	if (sb->s_bdev->bd_part)
3333 		sbi->s_sectors_written_start =
3334 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3335 
3336 	/* Cleanup superblock name */
3337 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3338 		*cp = '!';
3339 
3340 	/* -EINVAL is default */
3341 	ret = -EINVAL;
3342 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3343 	if (!blocksize) {
3344 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3345 		goto out_fail;
3346 	}
3347 
3348 	/*
3349 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3350 	 * block sizes.  We need to calculate the offset from buffer start.
3351 	 */
3352 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3353 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3354 		offset = do_div(logical_sb_block, blocksize);
3355 	} else {
3356 		logical_sb_block = sb_block;
3357 	}
3358 
3359 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3360 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3361 		goto out_fail;
3362 	}
3363 	/*
3364 	 * Note: s_es must be initialized as soon as possible because
3365 	 *       some ext4 macro-instructions depend on its value
3366 	 */
3367 	es = (struct ext4_super_block *) (bh->b_data + offset);
3368 	sbi->s_es = es;
3369 	sb->s_magic = le16_to_cpu(es->s_magic);
3370 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3371 		goto cantfind_ext4;
3372 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3373 
3374 	/* Warn if metadata_csum and gdt_csum are both set. */
3375 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3376 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3377 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3378 		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3379 			     "redundant flags; please run fsck.");
3380 
3381 	/* Check for a known checksum algorithm */
3382 	if (!ext4_verify_csum_type(sb, es)) {
3383 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3384 			 "unknown checksum algorithm.");
3385 		silent = 1;
3386 		goto cantfind_ext4;
3387 	}
3388 
3389 	/* Load the checksum driver */
3390 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3391 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3392 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3393 		if (IS_ERR(sbi->s_chksum_driver)) {
3394 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3395 			ret = PTR_ERR(sbi->s_chksum_driver);
3396 			sbi->s_chksum_driver = NULL;
3397 			goto failed_mount;
3398 		}
3399 	}
3400 
3401 	/* Check superblock checksum */
3402 	if (!ext4_superblock_csum_verify(sb, es)) {
3403 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3404 			 "invalid superblock checksum.  Run e2fsck?");
3405 		silent = 1;
3406 		goto cantfind_ext4;
3407 	}
3408 
3409 	/* Precompute checksum seed for all metadata */
3410 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3411 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3412 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3413 					       sizeof(es->s_uuid));
3414 
3415 	/* Set defaults before we parse the mount options */
3416 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3417 	set_opt(sb, INIT_INODE_TABLE);
3418 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3419 		set_opt(sb, DEBUG);
3420 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3421 		set_opt(sb, GRPID);
3422 	if (def_mount_opts & EXT4_DEFM_UID16)
3423 		set_opt(sb, NO_UID32);
3424 	/* xattr user namespace & acls are now defaulted on */
3425 	set_opt(sb, XATTR_USER);
3426 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3427 	set_opt(sb, POSIX_ACL);
3428 #endif
3429 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3430 		set_opt(sb, JOURNAL_DATA);
3431 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3432 		set_opt(sb, ORDERED_DATA);
3433 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3434 		set_opt(sb, WRITEBACK_DATA);
3435 
3436 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3437 		set_opt(sb, ERRORS_PANIC);
3438 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3439 		set_opt(sb, ERRORS_CONT);
3440 	else
3441 		set_opt(sb, ERRORS_RO);
3442 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3443 		set_opt(sb, BLOCK_VALIDITY);
3444 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3445 		set_opt(sb, DISCARD);
3446 
3447 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3448 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3449 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3450 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3451 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3452 
3453 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3454 		set_opt(sb, BARRIER);
3455 
3456 	/*
3457 	 * enable delayed allocation by default
3458 	 * Use -o nodelalloc to turn it off
3459 	 */
3460 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3461 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3462 		set_opt(sb, DELALLOC);
3463 
3464 	/*
3465 	 * set default s_li_wait_mult for lazyinit, for the case there is
3466 	 * no mount option specified.
3467 	 */
3468 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3469 
3470 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3471 			   &journal_devnum, &journal_ioprio, 0)) {
3472 		ext4_msg(sb, KERN_WARNING,
3473 			 "failed to parse options in superblock: %s",
3474 			 sbi->s_es->s_mount_opts);
3475 	}
3476 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3477 	if (!parse_options((char *) data, sb, &journal_devnum,
3478 			   &journal_ioprio, 0))
3479 		goto failed_mount;
3480 
3481 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3482 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3483 			    "with data=journal disables delayed "
3484 			    "allocation and O_DIRECT support!\n");
3485 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3486 			ext4_msg(sb, KERN_ERR, "can't mount with "
3487 				 "both data=journal and delalloc");
3488 			goto failed_mount;
3489 		}
3490 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3491 			ext4_msg(sb, KERN_ERR, "can't mount with "
3492 				 "both data=journal and delalloc");
3493 			goto failed_mount;
3494 		}
3495 		if (test_opt(sb, DELALLOC))
3496 			clear_opt(sb, DELALLOC);
3497 	}
3498 
3499 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3500 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3501 
3502 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3503 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3504 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3505 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3506 		ext4_msg(sb, KERN_WARNING,
3507 		       "feature flags set on rev 0 fs, "
3508 		       "running e2fsck is recommended");
3509 
3510 	if (IS_EXT2_SB(sb)) {
3511 		if (ext2_feature_set_ok(sb))
3512 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3513 				 "using the ext4 subsystem");
3514 		else {
3515 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3516 				 "to feature incompatibilities");
3517 			goto failed_mount;
3518 		}
3519 	}
3520 
3521 	if (IS_EXT3_SB(sb)) {
3522 		if (ext3_feature_set_ok(sb))
3523 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3524 				 "using the ext4 subsystem");
3525 		else {
3526 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3527 				 "to feature incompatibilities");
3528 			goto failed_mount;
3529 		}
3530 	}
3531 
3532 	/*
3533 	 * Check feature flags regardless of the revision level, since we
3534 	 * previously didn't change the revision level when setting the flags,
3535 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3536 	 */
3537 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3538 		goto failed_mount;
3539 
3540 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3541 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3542 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3543 		ext4_msg(sb, KERN_ERR,
3544 		       "Unsupported filesystem blocksize %d", blocksize);
3545 		goto failed_mount;
3546 	}
3547 
3548 	if (sb->s_blocksize != blocksize) {
3549 		/* Validate the filesystem blocksize */
3550 		if (!sb_set_blocksize(sb, blocksize)) {
3551 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3552 					blocksize);
3553 			goto failed_mount;
3554 		}
3555 
3556 		brelse(bh);
3557 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3558 		offset = do_div(logical_sb_block, blocksize);
3559 		bh = sb_bread(sb, logical_sb_block);
3560 		if (!bh) {
3561 			ext4_msg(sb, KERN_ERR,
3562 			       "Can't read superblock on 2nd try");
3563 			goto failed_mount;
3564 		}
3565 		es = (struct ext4_super_block *)(bh->b_data + offset);
3566 		sbi->s_es = es;
3567 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3568 			ext4_msg(sb, KERN_ERR,
3569 			       "Magic mismatch, very weird!");
3570 			goto failed_mount;
3571 		}
3572 	}
3573 
3574 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3575 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3576 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3577 						      has_huge_files);
3578 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3579 
3580 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3581 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3582 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3583 	} else {
3584 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3585 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3586 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3587 		    (!is_power_of_2(sbi->s_inode_size)) ||
3588 		    (sbi->s_inode_size > blocksize)) {
3589 			ext4_msg(sb, KERN_ERR,
3590 			       "unsupported inode size: %d",
3591 			       sbi->s_inode_size);
3592 			goto failed_mount;
3593 		}
3594 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3595 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3596 	}
3597 
3598 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3599 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3600 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3601 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3602 		    !is_power_of_2(sbi->s_desc_size)) {
3603 			ext4_msg(sb, KERN_ERR,
3604 			       "unsupported descriptor size %lu",
3605 			       sbi->s_desc_size);
3606 			goto failed_mount;
3607 		}
3608 	} else
3609 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3610 
3611 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3612 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3613 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3614 		goto cantfind_ext4;
3615 
3616 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3617 	if (sbi->s_inodes_per_block == 0)
3618 		goto cantfind_ext4;
3619 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3620 					sbi->s_inodes_per_block;
3621 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3622 	sbi->s_sbh = bh;
3623 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3624 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3625 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3626 
3627 	/* Do we have standard group size of blocksize * 8 blocks ? */
3628 	if (sbi->s_blocks_per_group == blocksize << 3)
3629 		set_opt2(sb, STD_GROUP_SIZE);
3630 
3631 	for (i = 0; i < 4; i++)
3632 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3633 	sbi->s_def_hash_version = es->s_def_hash_version;
3634 	i = le32_to_cpu(es->s_flags);
3635 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3636 		sbi->s_hash_unsigned = 3;
3637 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3638 #ifdef __CHAR_UNSIGNED__
3639 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3640 		sbi->s_hash_unsigned = 3;
3641 #else
3642 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3643 #endif
3644 	}
3645 
3646 	/* Handle clustersize */
3647 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3648 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3649 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3650 	if (has_bigalloc) {
3651 		if (clustersize < blocksize) {
3652 			ext4_msg(sb, KERN_ERR,
3653 				 "cluster size (%d) smaller than "
3654 				 "block size (%d)", clustersize, blocksize);
3655 			goto failed_mount;
3656 		}
3657 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3658 			le32_to_cpu(es->s_log_block_size);
3659 		sbi->s_clusters_per_group =
3660 			le32_to_cpu(es->s_clusters_per_group);
3661 		if (sbi->s_clusters_per_group > blocksize * 8) {
3662 			ext4_msg(sb, KERN_ERR,
3663 				 "#clusters per group too big: %lu",
3664 				 sbi->s_clusters_per_group);
3665 			goto failed_mount;
3666 		}
3667 		if (sbi->s_blocks_per_group !=
3668 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3669 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3670 				 "clusters per group (%lu) inconsistent",
3671 				 sbi->s_blocks_per_group,
3672 				 sbi->s_clusters_per_group);
3673 			goto failed_mount;
3674 		}
3675 	} else {
3676 		if (clustersize != blocksize) {
3677 			ext4_warning(sb, "fragment/cluster size (%d) != "
3678 				     "block size (%d)", clustersize,
3679 				     blocksize);
3680 			clustersize = blocksize;
3681 		}
3682 		if (sbi->s_blocks_per_group > blocksize * 8) {
3683 			ext4_msg(sb, KERN_ERR,
3684 				 "#blocks per group too big: %lu",
3685 				 sbi->s_blocks_per_group);
3686 			goto failed_mount;
3687 		}
3688 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3689 		sbi->s_cluster_bits = 0;
3690 	}
3691 	sbi->s_cluster_ratio = clustersize / blocksize;
3692 
3693 	if (sbi->s_inodes_per_group > blocksize * 8) {
3694 		ext4_msg(sb, KERN_ERR,
3695 		       "#inodes per group too big: %lu",
3696 		       sbi->s_inodes_per_group);
3697 		goto failed_mount;
3698 	}
3699 
3700 	/*
3701 	 * Test whether we have more sectors than will fit in sector_t,
3702 	 * and whether the max offset is addressable by the page cache.
3703 	 */
3704 	err = generic_check_addressable(sb->s_blocksize_bits,
3705 					ext4_blocks_count(es));
3706 	if (err) {
3707 		ext4_msg(sb, KERN_ERR, "filesystem"
3708 			 " too large to mount safely on this system");
3709 		if (sizeof(sector_t) < 8)
3710 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3711 		goto failed_mount;
3712 	}
3713 
3714 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3715 		goto cantfind_ext4;
3716 
3717 	/* check blocks count against device size */
3718 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3719 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3720 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3721 		       "exceeds size of device (%llu blocks)",
3722 		       ext4_blocks_count(es), blocks_count);
3723 		goto failed_mount;
3724 	}
3725 
3726 	/*
3727 	 * It makes no sense for the first data block to be beyond the end
3728 	 * of the filesystem.
3729 	 */
3730 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3731 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3732 			 "block %u is beyond end of filesystem (%llu)",
3733 			 le32_to_cpu(es->s_first_data_block),
3734 			 ext4_blocks_count(es));
3735 		goto failed_mount;
3736 	}
3737 	blocks_count = (ext4_blocks_count(es) -
3738 			le32_to_cpu(es->s_first_data_block) +
3739 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3740 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3741 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3742 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3743 		       "(block count %llu, first data block %u, "
3744 		       "blocks per group %lu)", sbi->s_groups_count,
3745 		       ext4_blocks_count(es),
3746 		       le32_to_cpu(es->s_first_data_block),
3747 		       EXT4_BLOCKS_PER_GROUP(sb));
3748 		goto failed_mount;
3749 	}
3750 	sbi->s_groups_count = blocks_count;
3751 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3752 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3753 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3754 		   EXT4_DESC_PER_BLOCK(sb);
3755 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3756 					  sizeof(struct buffer_head *),
3757 					  GFP_KERNEL);
3758 	if (sbi->s_group_desc == NULL) {
3759 		ext4_msg(sb, KERN_ERR, "not enough memory");
3760 		ret = -ENOMEM;
3761 		goto failed_mount;
3762 	}
3763 
3764 	if (ext4_proc_root)
3765 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3766 
3767 	if (sbi->s_proc)
3768 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3769 				 &ext4_seq_options_fops, sb);
3770 
3771 	bgl_lock_init(sbi->s_blockgroup_lock);
3772 
3773 	for (i = 0; i < db_count; i++) {
3774 		block = descriptor_loc(sb, logical_sb_block, i);
3775 		sbi->s_group_desc[i] = sb_bread(sb, block);
3776 		if (!sbi->s_group_desc[i]) {
3777 			ext4_msg(sb, KERN_ERR,
3778 			       "can't read group descriptor %d", i);
3779 			db_count = i;
3780 			goto failed_mount2;
3781 		}
3782 	}
3783 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3784 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3785 		goto failed_mount2;
3786 	}
3787 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3788 		if (!ext4_fill_flex_info(sb)) {
3789 			ext4_msg(sb, KERN_ERR,
3790 			       "unable to initialize "
3791 			       "flex_bg meta info!");
3792 			goto failed_mount2;
3793 		}
3794 
3795 	sbi->s_gdb_count = db_count;
3796 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3797 	spin_lock_init(&sbi->s_next_gen_lock);
3798 
3799 	init_timer(&sbi->s_err_report);
3800 	sbi->s_err_report.function = print_daily_error_info;
3801 	sbi->s_err_report.data = (unsigned long) sb;
3802 
3803 	/* Register extent status tree shrinker */
3804 	ext4_es_register_shrinker(sbi);
3805 
3806 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3807 			ext4_count_free_clusters(sb));
3808 	if (!err) {
3809 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3810 				ext4_count_free_inodes(sb));
3811 	}
3812 	if (!err) {
3813 		err = percpu_counter_init(&sbi->s_dirs_counter,
3814 				ext4_count_dirs(sb));
3815 	}
3816 	if (!err) {
3817 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3818 	}
3819 	if (!err) {
3820 		err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3821 	}
3822 	if (err) {
3823 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3824 		goto failed_mount3;
3825 	}
3826 
3827 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3828 	sbi->s_extent_max_zeroout_kb = 32;
3829 
3830 	/*
3831 	 * set up enough so that it can read an inode
3832 	 */
3833 	if (!test_opt(sb, NOLOAD) &&
3834 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3835 		sb->s_op = &ext4_sops;
3836 	else
3837 		sb->s_op = &ext4_nojournal_sops;
3838 	sb->s_export_op = &ext4_export_ops;
3839 	sb->s_xattr = ext4_xattr_handlers;
3840 #ifdef CONFIG_QUOTA
3841 	sb->dq_op = &ext4_quota_operations;
3842 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3843 		sb->s_qcop = &ext4_qctl_sysfile_operations;
3844 	else
3845 		sb->s_qcop = &ext4_qctl_operations;
3846 #endif
3847 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3848 
3849 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3850 	mutex_init(&sbi->s_orphan_lock);
3851 
3852 	sb->s_root = NULL;
3853 
3854 	needs_recovery = (es->s_last_orphan != 0 ||
3855 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3856 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3857 
3858 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3859 	    !(sb->s_flags & MS_RDONLY))
3860 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3861 			goto failed_mount3;
3862 
3863 	/*
3864 	 * The first inode we look at is the journal inode.  Don't try
3865 	 * root first: it may be modified in the journal!
3866 	 */
3867 	if (!test_opt(sb, NOLOAD) &&
3868 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3869 		if (ext4_load_journal(sb, es, journal_devnum))
3870 			goto failed_mount3;
3871 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3872 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3873 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3874 		       "suppressed and not mounted read-only");
3875 		goto failed_mount_wq;
3876 	} else {
3877 		clear_opt(sb, DATA_FLAGS);
3878 		sbi->s_journal = NULL;
3879 		needs_recovery = 0;
3880 		goto no_journal;
3881 	}
3882 
3883 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3884 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3885 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3886 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3887 		goto failed_mount_wq;
3888 	}
3889 
3890 	if (!set_journal_csum_feature_set(sb)) {
3891 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3892 			 "feature set");
3893 		goto failed_mount_wq;
3894 	}
3895 
3896 	/* We have now updated the journal if required, so we can
3897 	 * validate the data journaling mode. */
3898 	switch (test_opt(sb, DATA_FLAGS)) {
3899 	case 0:
3900 		/* No mode set, assume a default based on the journal
3901 		 * capabilities: ORDERED_DATA if the journal can
3902 		 * cope, else JOURNAL_DATA
3903 		 */
3904 		if (jbd2_journal_check_available_features
3905 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3906 			set_opt(sb, ORDERED_DATA);
3907 		else
3908 			set_opt(sb, JOURNAL_DATA);
3909 		break;
3910 
3911 	case EXT4_MOUNT_ORDERED_DATA:
3912 	case EXT4_MOUNT_WRITEBACK_DATA:
3913 		if (!jbd2_journal_check_available_features
3914 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3915 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3916 			       "requested data journaling mode");
3917 			goto failed_mount_wq;
3918 		}
3919 	default:
3920 		break;
3921 	}
3922 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3923 
3924 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3925 
3926 	/*
3927 	 * The journal may have updated the bg summary counts, so we
3928 	 * need to update the global counters.
3929 	 */
3930 	percpu_counter_set(&sbi->s_freeclusters_counter,
3931 			   ext4_count_free_clusters(sb));
3932 	percpu_counter_set(&sbi->s_freeinodes_counter,
3933 			   ext4_count_free_inodes(sb));
3934 	percpu_counter_set(&sbi->s_dirs_counter,
3935 			   ext4_count_dirs(sb));
3936 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3937 
3938 no_journal:
3939 	/*
3940 	 * Get the # of file system overhead blocks from the
3941 	 * superblock if present.
3942 	 */
3943 	if (es->s_overhead_clusters)
3944 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3945 	else {
3946 		err = ext4_calculate_overhead(sb);
3947 		if (err)
3948 			goto failed_mount_wq;
3949 	}
3950 
3951 	/*
3952 	 * The maximum number of concurrent works can be high and
3953 	 * concurrency isn't really necessary.  Limit it to 1.
3954 	 */
3955 	EXT4_SB(sb)->rsv_conversion_wq =
3956 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3957 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
3958 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3959 		ret = -ENOMEM;
3960 		goto failed_mount4;
3961 	}
3962 
3963 	EXT4_SB(sb)->unrsv_conversion_wq =
3964 		alloc_workqueue("ext4-unrsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3965 	if (!EXT4_SB(sb)->unrsv_conversion_wq) {
3966 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3967 		ret = -ENOMEM;
3968 		goto failed_mount4;
3969 	}
3970 
3971 	/*
3972 	 * The jbd2_journal_load will have done any necessary log recovery,
3973 	 * so we can safely mount the rest of the filesystem now.
3974 	 */
3975 
3976 	root = ext4_iget(sb, EXT4_ROOT_INO);
3977 	if (IS_ERR(root)) {
3978 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3979 		ret = PTR_ERR(root);
3980 		root = NULL;
3981 		goto failed_mount4;
3982 	}
3983 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3984 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3985 		iput(root);
3986 		goto failed_mount4;
3987 	}
3988 	sb->s_root = d_make_root(root);
3989 	if (!sb->s_root) {
3990 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3991 		ret = -ENOMEM;
3992 		goto failed_mount4;
3993 	}
3994 
3995 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3996 		sb->s_flags |= MS_RDONLY;
3997 
3998 	/* determine the minimum size of new large inodes, if present */
3999 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4000 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4001 						     EXT4_GOOD_OLD_INODE_SIZE;
4002 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4003 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4004 			if (sbi->s_want_extra_isize <
4005 			    le16_to_cpu(es->s_want_extra_isize))
4006 				sbi->s_want_extra_isize =
4007 					le16_to_cpu(es->s_want_extra_isize);
4008 			if (sbi->s_want_extra_isize <
4009 			    le16_to_cpu(es->s_min_extra_isize))
4010 				sbi->s_want_extra_isize =
4011 					le16_to_cpu(es->s_min_extra_isize);
4012 		}
4013 	}
4014 	/* Check if enough inode space is available */
4015 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4016 							sbi->s_inode_size) {
4017 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4018 						       EXT4_GOOD_OLD_INODE_SIZE;
4019 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4020 			 "available");
4021 	}
4022 
4023 	err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sbi));
4024 	if (err) {
4025 		ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4026 			 "reserved pool", ext4_calculate_resv_clusters(sbi));
4027 		goto failed_mount4a;
4028 	}
4029 
4030 	err = ext4_setup_system_zone(sb);
4031 	if (err) {
4032 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4033 			 "zone (%d)", err);
4034 		goto failed_mount4a;
4035 	}
4036 
4037 	ext4_ext_init(sb);
4038 	err = ext4_mb_init(sb);
4039 	if (err) {
4040 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4041 			 err);
4042 		goto failed_mount5;
4043 	}
4044 
4045 	err = ext4_register_li_request(sb, first_not_zeroed);
4046 	if (err)
4047 		goto failed_mount6;
4048 
4049 	sbi->s_kobj.kset = ext4_kset;
4050 	init_completion(&sbi->s_kobj_unregister);
4051 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4052 				   "%s", sb->s_id);
4053 	if (err)
4054 		goto failed_mount7;
4055 
4056 #ifdef CONFIG_QUOTA
4057 	/* Enable quota usage during mount. */
4058 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4059 	    !(sb->s_flags & MS_RDONLY)) {
4060 		err = ext4_enable_quotas(sb);
4061 		if (err)
4062 			goto failed_mount8;
4063 	}
4064 #endif  /* CONFIG_QUOTA */
4065 
4066 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4067 	ext4_orphan_cleanup(sb, es);
4068 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4069 	if (needs_recovery) {
4070 		ext4_msg(sb, KERN_INFO, "recovery complete");
4071 		ext4_mark_recovery_complete(sb, es);
4072 	}
4073 	if (EXT4_SB(sb)->s_journal) {
4074 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4075 			descr = " journalled data mode";
4076 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4077 			descr = " ordered data mode";
4078 		else
4079 			descr = " writeback data mode";
4080 	} else
4081 		descr = "out journal";
4082 
4083 	if (test_opt(sb, DISCARD)) {
4084 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4085 		if (!blk_queue_discard(q))
4086 			ext4_msg(sb, KERN_WARNING,
4087 				 "mounting with \"discard\" option, but "
4088 				 "the device does not support discard");
4089 	}
4090 
4091 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4092 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4093 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4094 
4095 	if (es->s_error_count)
4096 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4097 
4098 	kfree(orig_data);
4099 	return 0;
4100 
4101 cantfind_ext4:
4102 	if (!silent)
4103 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4104 	goto failed_mount;
4105 
4106 #ifdef CONFIG_QUOTA
4107 failed_mount8:
4108 	kobject_del(&sbi->s_kobj);
4109 #endif
4110 failed_mount7:
4111 	ext4_unregister_li_request(sb);
4112 failed_mount6:
4113 	ext4_mb_release(sb);
4114 failed_mount5:
4115 	ext4_ext_release(sb);
4116 	ext4_release_system_zone(sb);
4117 failed_mount4a:
4118 	dput(sb->s_root);
4119 	sb->s_root = NULL;
4120 failed_mount4:
4121 	ext4_msg(sb, KERN_ERR, "mount failed");
4122 	if (EXT4_SB(sb)->rsv_conversion_wq)
4123 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4124 	if (EXT4_SB(sb)->unrsv_conversion_wq)
4125 		destroy_workqueue(EXT4_SB(sb)->unrsv_conversion_wq);
4126 failed_mount_wq:
4127 	if (sbi->s_journal) {
4128 		jbd2_journal_destroy(sbi->s_journal);
4129 		sbi->s_journal = NULL;
4130 	}
4131 failed_mount3:
4132 	ext4_es_unregister_shrinker(sbi);
4133 	del_timer(&sbi->s_err_report);
4134 	if (sbi->s_flex_groups)
4135 		ext4_kvfree(sbi->s_flex_groups);
4136 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4137 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4138 	percpu_counter_destroy(&sbi->s_dirs_counter);
4139 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4140 	percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4141 	if (sbi->s_mmp_tsk)
4142 		kthread_stop(sbi->s_mmp_tsk);
4143 failed_mount2:
4144 	for (i = 0; i < db_count; i++)
4145 		brelse(sbi->s_group_desc[i]);
4146 	ext4_kvfree(sbi->s_group_desc);
4147 failed_mount:
4148 	if (sbi->s_chksum_driver)
4149 		crypto_free_shash(sbi->s_chksum_driver);
4150 	if (sbi->s_proc) {
4151 		remove_proc_entry("options", sbi->s_proc);
4152 		remove_proc_entry(sb->s_id, ext4_proc_root);
4153 	}
4154 #ifdef CONFIG_QUOTA
4155 	for (i = 0; i < MAXQUOTAS; i++)
4156 		kfree(sbi->s_qf_names[i]);
4157 #endif
4158 	ext4_blkdev_remove(sbi);
4159 	brelse(bh);
4160 out_fail:
4161 	sb->s_fs_info = NULL;
4162 	kfree(sbi->s_blockgroup_lock);
4163 	kfree(sbi);
4164 out_free_orig:
4165 	kfree(orig_data);
4166 	return err ? err : ret;
4167 }
4168 
4169 /*
4170  * Setup any per-fs journal parameters now.  We'll do this both on
4171  * initial mount, once the journal has been initialised but before we've
4172  * done any recovery; and again on any subsequent remount.
4173  */
4174 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4175 {
4176 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4177 
4178 	journal->j_commit_interval = sbi->s_commit_interval;
4179 	journal->j_min_batch_time = sbi->s_min_batch_time;
4180 	journal->j_max_batch_time = sbi->s_max_batch_time;
4181 
4182 	write_lock(&journal->j_state_lock);
4183 	if (test_opt(sb, BARRIER))
4184 		journal->j_flags |= JBD2_BARRIER;
4185 	else
4186 		journal->j_flags &= ~JBD2_BARRIER;
4187 	if (test_opt(sb, DATA_ERR_ABORT))
4188 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4189 	else
4190 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4191 	write_unlock(&journal->j_state_lock);
4192 }
4193 
4194 static journal_t *ext4_get_journal(struct super_block *sb,
4195 				   unsigned int journal_inum)
4196 {
4197 	struct inode *journal_inode;
4198 	journal_t *journal;
4199 
4200 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4201 
4202 	/* First, test for the existence of a valid inode on disk.  Bad
4203 	 * things happen if we iget() an unused inode, as the subsequent
4204 	 * iput() will try to delete it. */
4205 
4206 	journal_inode = ext4_iget(sb, journal_inum);
4207 	if (IS_ERR(journal_inode)) {
4208 		ext4_msg(sb, KERN_ERR, "no journal found");
4209 		return NULL;
4210 	}
4211 	if (!journal_inode->i_nlink) {
4212 		make_bad_inode(journal_inode);
4213 		iput(journal_inode);
4214 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4215 		return NULL;
4216 	}
4217 
4218 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4219 		  journal_inode, journal_inode->i_size);
4220 	if (!S_ISREG(journal_inode->i_mode)) {
4221 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4222 		iput(journal_inode);
4223 		return NULL;
4224 	}
4225 
4226 	journal = jbd2_journal_init_inode(journal_inode);
4227 	if (!journal) {
4228 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4229 		iput(journal_inode);
4230 		return NULL;
4231 	}
4232 	journal->j_private = sb;
4233 	ext4_init_journal_params(sb, journal);
4234 	return journal;
4235 }
4236 
4237 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4238 				       dev_t j_dev)
4239 {
4240 	struct buffer_head *bh;
4241 	journal_t *journal;
4242 	ext4_fsblk_t start;
4243 	ext4_fsblk_t len;
4244 	int hblock, blocksize;
4245 	ext4_fsblk_t sb_block;
4246 	unsigned long offset;
4247 	struct ext4_super_block *es;
4248 	struct block_device *bdev;
4249 
4250 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4251 
4252 	bdev = ext4_blkdev_get(j_dev, sb);
4253 	if (bdev == NULL)
4254 		return NULL;
4255 
4256 	blocksize = sb->s_blocksize;
4257 	hblock = bdev_logical_block_size(bdev);
4258 	if (blocksize < hblock) {
4259 		ext4_msg(sb, KERN_ERR,
4260 			"blocksize too small for journal device");
4261 		goto out_bdev;
4262 	}
4263 
4264 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4265 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4266 	set_blocksize(bdev, blocksize);
4267 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4268 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4269 		       "external journal");
4270 		goto out_bdev;
4271 	}
4272 
4273 	es = (struct ext4_super_block *) (bh->b_data + offset);
4274 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4275 	    !(le32_to_cpu(es->s_feature_incompat) &
4276 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4277 		ext4_msg(sb, KERN_ERR, "external journal has "
4278 					"bad superblock");
4279 		brelse(bh);
4280 		goto out_bdev;
4281 	}
4282 
4283 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4284 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4285 		brelse(bh);
4286 		goto out_bdev;
4287 	}
4288 
4289 	len = ext4_blocks_count(es);
4290 	start = sb_block + 1;
4291 	brelse(bh);	/* we're done with the superblock */
4292 
4293 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4294 					start, len, blocksize);
4295 	if (!journal) {
4296 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4297 		goto out_bdev;
4298 	}
4299 	journal->j_private = sb;
4300 	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4301 	wait_on_buffer(journal->j_sb_buffer);
4302 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4303 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4304 		goto out_journal;
4305 	}
4306 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4307 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4308 					"user (unsupported) - %d",
4309 			be32_to_cpu(journal->j_superblock->s_nr_users));
4310 		goto out_journal;
4311 	}
4312 	EXT4_SB(sb)->journal_bdev = bdev;
4313 	ext4_init_journal_params(sb, journal);
4314 	return journal;
4315 
4316 out_journal:
4317 	jbd2_journal_destroy(journal);
4318 out_bdev:
4319 	ext4_blkdev_put(bdev);
4320 	return NULL;
4321 }
4322 
4323 static int ext4_load_journal(struct super_block *sb,
4324 			     struct ext4_super_block *es,
4325 			     unsigned long journal_devnum)
4326 {
4327 	journal_t *journal;
4328 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4329 	dev_t journal_dev;
4330 	int err = 0;
4331 	int really_read_only;
4332 
4333 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4334 
4335 	if (journal_devnum &&
4336 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4337 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4338 			"numbers have changed");
4339 		journal_dev = new_decode_dev(journal_devnum);
4340 	} else
4341 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4342 
4343 	really_read_only = bdev_read_only(sb->s_bdev);
4344 
4345 	/*
4346 	 * Are we loading a blank journal or performing recovery after a
4347 	 * crash?  For recovery, we need to check in advance whether we
4348 	 * can get read-write access to the device.
4349 	 */
4350 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4351 		if (sb->s_flags & MS_RDONLY) {
4352 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4353 					"required on readonly filesystem");
4354 			if (really_read_only) {
4355 				ext4_msg(sb, KERN_ERR, "write access "
4356 					"unavailable, cannot proceed");
4357 				return -EROFS;
4358 			}
4359 			ext4_msg(sb, KERN_INFO, "write access will "
4360 			       "be enabled during recovery");
4361 		}
4362 	}
4363 
4364 	if (journal_inum && journal_dev) {
4365 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4366 		       "and inode journals!");
4367 		return -EINVAL;
4368 	}
4369 
4370 	if (journal_inum) {
4371 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4372 			return -EINVAL;
4373 	} else {
4374 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4375 			return -EINVAL;
4376 	}
4377 
4378 	if (!(journal->j_flags & JBD2_BARRIER))
4379 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4380 
4381 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4382 		err = jbd2_journal_wipe(journal, !really_read_only);
4383 	if (!err) {
4384 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4385 		if (save)
4386 			memcpy(save, ((char *) es) +
4387 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4388 		err = jbd2_journal_load(journal);
4389 		if (save)
4390 			memcpy(((char *) es) + EXT4_S_ERR_START,
4391 			       save, EXT4_S_ERR_LEN);
4392 		kfree(save);
4393 	}
4394 
4395 	if (err) {
4396 		ext4_msg(sb, KERN_ERR, "error loading journal");
4397 		jbd2_journal_destroy(journal);
4398 		return err;
4399 	}
4400 
4401 	EXT4_SB(sb)->s_journal = journal;
4402 	ext4_clear_journal_err(sb, es);
4403 
4404 	if (!really_read_only && journal_devnum &&
4405 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4406 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4407 
4408 		/* Make sure we flush the recovery flag to disk. */
4409 		ext4_commit_super(sb, 1);
4410 	}
4411 
4412 	return 0;
4413 }
4414 
4415 static int ext4_commit_super(struct super_block *sb, int sync)
4416 {
4417 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4418 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4419 	int error = 0;
4420 
4421 	if (!sbh || block_device_ejected(sb))
4422 		return error;
4423 	if (buffer_write_io_error(sbh)) {
4424 		/*
4425 		 * Oh, dear.  A previous attempt to write the
4426 		 * superblock failed.  This could happen because the
4427 		 * USB device was yanked out.  Or it could happen to
4428 		 * be a transient write error and maybe the block will
4429 		 * be remapped.  Nothing we can do but to retry the
4430 		 * write and hope for the best.
4431 		 */
4432 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4433 		       "superblock detected");
4434 		clear_buffer_write_io_error(sbh);
4435 		set_buffer_uptodate(sbh);
4436 	}
4437 	/*
4438 	 * If the file system is mounted read-only, don't update the
4439 	 * superblock write time.  This avoids updating the superblock
4440 	 * write time when we are mounting the root file system
4441 	 * read/only but we need to replay the journal; at that point,
4442 	 * for people who are east of GMT and who make their clock
4443 	 * tick in localtime for Windows bug-for-bug compatibility,
4444 	 * the clock is set in the future, and this will cause e2fsck
4445 	 * to complain and force a full file system check.
4446 	 */
4447 	if (!(sb->s_flags & MS_RDONLY))
4448 		es->s_wtime = cpu_to_le32(get_seconds());
4449 	if (sb->s_bdev->bd_part)
4450 		es->s_kbytes_written =
4451 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4452 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4453 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4454 	else
4455 		es->s_kbytes_written =
4456 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4457 	ext4_free_blocks_count_set(es,
4458 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4459 				&EXT4_SB(sb)->s_freeclusters_counter)));
4460 	es->s_free_inodes_count =
4461 		cpu_to_le32(percpu_counter_sum_positive(
4462 				&EXT4_SB(sb)->s_freeinodes_counter));
4463 	BUFFER_TRACE(sbh, "marking dirty");
4464 	ext4_superblock_csum_set(sb);
4465 	mark_buffer_dirty(sbh);
4466 	if (sync) {
4467 		error = sync_dirty_buffer(sbh);
4468 		if (error)
4469 			return error;
4470 
4471 		error = buffer_write_io_error(sbh);
4472 		if (error) {
4473 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4474 			       "superblock");
4475 			clear_buffer_write_io_error(sbh);
4476 			set_buffer_uptodate(sbh);
4477 		}
4478 	}
4479 	return error;
4480 }
4481 
4482 /*
4483  * Have we just finished recovery?  If so, and if we are mounting (or
4484  * remounting) the filesystem readonly, then we will end up with a
4485  * consistent fs on disk.  Record that fact.
4486  */
4487 static void ext4_mark_recovery_complete(struct super_block *sb,
4488 					struct ext4_super_block *es)
4489 {
4490 	journal_t *journal = EXT4_SB(sb)->s_journal;
4491 
4492 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4493 		BUG_ON(journal != NULL);
4494 		return;
4495 	}
4496 	jbd2_journal_lock_updates(journal);
4497 	if (jbd2_journal_flush(journal) < 0)
4498 		goto out;
4499 
4500 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4501 	    sb->s_flags & MS_RDONLY) {
4502 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4503 		ext4_commit_super(sb, 1);
4504 	}
4505 
4506 out:
4507 	jbd2_journal_unlock_updates(journal);
4508 }
4509 
4510 /*
4511  * If we are mounting (or read-write remounting) a filesystem whose journal
4512  * has recorded an error from a previous lifetime, move that error to the
4513  * main filesystem now.
4514  */
4515 static void ext4_clear_journal_err(struct super_block *sb,
4516 				   struct ext4_super_block *es)
4517 {
4518 	journal_t *journal;
4519 	int j_errno;
4520 	const char *errstr;
4521 
4522 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4523 
4524 	journal = EXT4_SB(sb)->s_journal;
4525 
4526 	/*
4527 	 * Now check for any error status which may have been recorded in the
4528 	 * journal by a prior ext4_error() or ext4_abort()
4529 	 */
4530 
4531 	j_errno = jbd2_journal_errno(journal);
4532 	if (j_errno) {
4533 		char nbuf[16];
4534 
4535 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4536 		ext4_warning(sb, "Filesystem error recorded "
4537 			     "from previous mount: %s", errstr);
4538 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4539 
4540 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4541 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4542 		ext4_commit_super(sb, 1);
4543 
4544 		jbd2_journal_clear_err(journal);
4545 		jbd2_journal_update_sb_errno(journal);
4546 	}
4547 }
4548 
4549 /*
4550  * Force the running and committing transactions to commit,
4551  * and wait on the commit.
4552  */
4553 int ext4_force_commit(struct super_block *sb)
4554 {
4555 	journal_t *journal;
4556 
4557 	if (sb->s_flags & MS_RDONLY)
4558 		return 0;
4559 
4560 	journal = EXT4_SB(sb)->s_journal;
4561 	return ext4_journal_force_commit(journal);
4562 }
4563 
4564 static int ext4_sync_fs(struct super_block *sb, int wait)
4565 {
4566 	int ret = 0;
4567 	tid_t target;
4568 	bool needs_barrier = false;
4569 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4570 
4571 	trace_ext4_sync_fs(sb, wait);
4572 	flush_workqueue(sbi->rsv_conversion_wq);
4573 	flush_workqueue(sbi->unrsv_conversion_wq);
4574 	/*
4575 	 * Writeback quota in non-journalled quota case - journalled quota has
4576 	 * no dirty dquots
4577 	 */
4578 	dquot_writeback_dquots(sb, -1);
4579 	/*
4580 	 * Data writeback is possible w/o journal transaction, so barrier must
4581 	 * being sent at the end of the function. But we can skip it if
4582 	 * transaction_commit will do it for us.
4583 	 */
4584 	target = jbd2_get_latest_transaction(sbi->s_journal);
4585 	if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4586 	    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4587 		needs_barrier = true;
4588 
4589 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4590 		if (wait)
4591 			ret = jbd2_log_wait_commit(sbi->s_journal, target);
4592 	}
4593 	if (needs_barrier) {
4594 		int err;
4595 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4596 		if (!ret)
4597 			ret = err;
4598 	}
4599 
4600 	return ret;
4601 }
4602 
4603 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4604 {
4605 	int ret = 0;
4606 
4607 	trace_ext4_sync_fs(sb, wait);
4608 	flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4609 	flush_workqueue(EXT4_SB(sb)->unrsv_conversion_wq);
4610 	dquot_writeback_dquots(sb, -1);
4611 	if (wait && test_opt(sb, BARRIER))
4612 		ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4613 
4614 	return ret;
4615 }
4616 
4617 /*
4618  * LVM calls this function before a (read-only) snapshot is created.  This
4619  * gives us a chance to flush the journal completely and mark the fs clean.
4620  *
4621  * Note that only this function cannot bring a filesystem to be in a clean
4622  * state independently. It relies on upper layer to stop all data & metadata
4623  * modifications.
4624  */
4625 static int ext4_freeze(struct super_block *sb)
4626 {
4627 	int error = 0;
4628 	journal_t *journal;
4629 
4630 	if (sb->s_flags & MS_RDONLY)
4631 		return 0;
4632 
4633 	journal = EXT4_SB(sb)->s_journal;
4634 
4635 	/* Now we set up the journal barrier. */
4636 	jbd2_journal_lock_updates(journal);
4637 
4638 	/*
4639 	 * Don't clear the needs_recovery flag if we failed to flush
4640 	 * the journal.
4641 	 */
4642 	error = jbd2_journal_flush(journal);
4643 	if (error < 0)
4644 		goto out;
4645 
4646 	/* Journal blocked and flushed, clear needs_recovery flag. */
4647 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4648 	error = ext4_commit_super(sb, 1);
4649 out:
4650 	/* we rely on upper layer to stop further updates */
4651 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4652 	return error;
4653 }
4654 
4655 /*
4656  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4657  * flag here, even though the filesystem is not technically dirty yet.
4658  */
4659 static int ext4_unfreeze(struct super_block *sb)
4660 {
4661 	if (sb->s_flags & MS_RDONLY)
4662 		return 0;
4663 
4664 	/* Reset the needs_recovery flag before the fs is unlocked. */
4665 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4666 	ext4_commit_super(sb, 1);
4667 	return 0;
4668 }
4669 
4670 /*
4671  * Structure to save mount options for ext4_remount's benefit
4672  */
4673 struct ext4_mount_options {
4674 	unsigned long s_mount_opt;
4675 	unsigned long s_mount_opt2;
4676 	kuid_t s_resuid;
4677 	kgid_t s_resgid;
4678 	unsigned long s_commit_interval;
4679 	u32 s_min_batch_time, s_max_batch_time;
4680 #ifdef CONFIG_QUOTA
4681 	int s_jquota_fmt;
4682 	char *s_qf_names[MAXQUOTAS];
4683 #endif
4684 };
4685 
4686 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4687 {
4688 	struct ext4_super_block *es;
4689 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4690 	unsigned long old_sb_flags;
4691 	struct ext4_mount_options old_opts;
4692 	int enable_quota = 0;
4693 	ext4_group_t g;
4694 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4695 	int err = 0;
4696 #ifdef CONFIG_QUOTA
4697 	int i, j;
4698 #endif
4699 	char *orig_data = kstrdup(data, GFP_KERNEL);
4700 
4701 	/* Store the original options */
4702 	old_sb_flags = sb->s_flags;
4703 	old_opts.s_mount_opt = sbi->s_mount_opt;
4704 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4705 	old_opts.s_resuid = sbi->s_resuid;
4706 	old_opts.s_resgid = sbi->s_resgid;
4707 	old_opts.s_commit_interval = sbi->s_commit_interval;
4708 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4709 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4710 #ifdef CONFIG_QUOTA
4711 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4712 	for (i = 0; i < MAXQUOTAS; i++)
4713 		if (sbi->s_qf_names[i]) {
4714 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4715 							 GFP_KERNEL);
4716 			if (!old_opts.s_qf_names[i]) {
4717 				for (j = 0; j < i; j++)
4718 					kfree(old_opts.s_qf_names[j]);
4719 				kfree(orig_data);
4720 				return -ENOMEM;
4721 			}
4722 		} else
4723 			old_opts.s_qf_names[i] = NULL;
4724 #endif
4725 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4726 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4727 
4728 	/*
4729 	 * Allow the "check" option to be passed as a remount option.
4730 	 */
4731 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4732 		err = -EINVAL;
4733 		goto restore_opts;
4734 	}
4735 
4736 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4737 		ext4_abort(sb, "Abort forced by user");
4738 
4739 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4740 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4741 
4742 	es = sbi->s_es;
4743 
4744 	if (sbi->s_journal) {
4745 		ext4_init_journal_params(sb, sbi->s_journal);
4746 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4747 	}
4748 
4749 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4750 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4751 			err = -EROFS;
4752 			goto restore_opts;
4753 		}
4754 
4755 		if (*flags & MS_RDONLY) {
4756 			err = dquot_suspend(sb, -1);
4757 			if (err < 0)
4758 				goto restore_opts;
4759 
4760 			/*
4761 			 * First of all, the unconditional stuff we have to do
4762 			 * to disable replay of the journal when we next remount
4763 			 */
4764 			sb->s_flags |= MS_RDONLY;
4765 
4766 			/*
4767 			 * OK, test if we are remounting a valid rw partition
4768 			 * readonly, and if so set the rdonly flag and then
4769 			 * mark the partition as valid again.
4770 			 */
4771 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4772 			    (sbi->s_mount_state & EXT4_VALID_FS))
4773 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4774 
4775 			if (sbi->s_journal)
4776 				ext4_mark_recovery_complete(sb, es);
4777 		} else {
4778 			/* Make sure we can mount this feature set readwrite */
4779 			if (!ext4_feature_set_ok(sb, 0)) {
4780 				err = -EROFS;
4781 				goto restore_opts;
4782 			}
4783 			/*
4784 			 * Make sure the group descriptor checksums
4785 			 * are sane.  If they aren't, refuse to remount r/w.
4786 			 */
4787 			for (g = 0; g < sbi->s_groups_count; g++) {
4788 				struct ext4_group_desc *gdp =
4789 					ext4_get_group_desc(sb, g, NULL);
4790 
4791 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4792 					ext4_msg(sb, KERN_ERR,
4793 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4794 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4795 					       le16_to_cpu(gdp->bg_checksum));
4796 					err = -EINVAL;
4797 					goto restore_opts;
4798 				}
4799 			}
4800 
4801 			/*
4802 			 * If we have an unprocessed orphan list hanging
4803 			 * around from a previously readonly bdev mount,
4804 			 * require a full umount/remount for now.
4805 			 */
4806 			if (es->s_last_orphan) {
4807 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4808 				       "remount RDWR because of unprocessed "
4809 				       "orphan inode list.  Please "
4810 				       "umount/remount instead");
4811 				err = -EINVAL;
4812 				goto restore_opts;
4813 			}
4814 
4815 			/*
4816 			 * Mounting a RDONLY partition read-write, so reread
4817 			 * and store the current valid flag.  (It may have
4818 			 * been changed by e2fsck since we originally mounted
4819 			 * the partition.)
4820 			 */
4821 			if (sbi->s_journal)
4822 				ext4_clear_journal_err(sb, es);
4823 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4824 			if (!ext4_setup_super(sb, es, 0))
4825 				sb->s_flags &= ~MS_RDONLY;
4826 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4827 						     EXT4_FEATURE_INCOMPAT_MMP))
4828 				if (ext4_multi_mount_protect(sb,
4829 						le64_to_cpu(es->s_mmp_block))) {
4830 					err = -EROFS;
4831 					goto restore_opts;
4832 				}
4833 			enable_quota = 1;
4834 		}
4835 	}
4836 
4837 	/*
4838 	 * Reinitialize lazy itable initialization thread based on
4839 	 * current settings
4840 	 */
4841 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4842 		ext4_unregister_li_request(sb);
4843 	else {
4844 		ext4_group_t first_not_zeroed;
4845 		first_not_zeroed = ext4_has_uninit_itable(sb);
4846 		ext4_register_li_request(sb, first_not_zeroed);
4847 	}
4848 
4849 	ext4_setup_system_zone(sb);
4850 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4851 		ext4_commit_super(sb, 1);
4852 
4853 #ifdef CONFIG_QUOTA
4854 	/* Release old quota file names */
4855 	for (i = 0; i < MAXQUOTAS; i++)
4856 		kfree(old_opts.s_qf_names[i]);
4857 	if (enable_quota) {
4858 		if (sb_any_quota_suspended(sb))
4859 			dquot_resume(sb, -1);
4860 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4861 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4862 			err = ext4_enable_quotas(sb);
4863 			if (err)
4864 				goto restore_opts;
4865 		}
4866 	}
4867 #endif
4868 
4869 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4870 	kfree(orig_data);
4871 	return 0;
4872 
4873 restore_opts:
4874 	sb->s_flags = old_sb_flags;
4875 	sbi->s_mount_opt = old_opts.s_mount_opt;
4876 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4877 	sbi->s_resuid = old_opts.s_resuid;
4878 	sbi->s_resgid = old_opts.s_resgid;
4879 	sbi->s_commit_interval = old_opts.s_commit_interval;
4880 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4881 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4882 #ifdef CONFIG_QUOTA
4883 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4884 	for (i = 0; i < MAXQUOTAS; i++) {
4885 		kfree(sbi->s_qf_names[i]);
4886 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4887 	}
4888 #endif
4889 	kfree(orig_data);
4890 	return err;
4891 }
4892 
4893 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4894 {
4895 	struct super_block *sb = dentry->d_sb;
4896 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4897 	struct ext4_super_block *es = sbi->s_es;
4898 	ext4_fsblk_t overhead = 0, resv_blocks;
4899 	u64 fsid;
4900 	s64 bfree;
4901 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4902 
4903 	if (!test_opt(sb, MINIX_DF))
4904 		overhead = sbi->s_overhead;
4905 
4906 	buf->f_type = EXT4_SUPER_MAGIC;
4907 	buf->f_bsize = sb->s_blocksize;
4908 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4909 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4910 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4911 	/* prevent underflow in case that few free space is available */
4912 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4913 	buf->f_bavail = buf->f_bfree -
4914 			(ext4_r_blocks_count(es) + resv_blocks);
4915 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4916 		buf->f_bavail = 0;
4917 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4918 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4919 	buf->f_namelen = EXT4_NAME_LEN;
4920 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4921 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4922 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4923 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4924 
4925 	return 0;
4926 }
4927 
4928 /* Helper function for writing quotas on sync - we need to start transaction
4929  * before quota file is locked for write. Otherwise the are possible deadlocks:
4930  * Process 1                         Process 2
4931  * ext4_create()                     quota_sync()
4932  *   jbd2_journal_start()                  write_dquot()
4933  *   dquot_initialize()                         down(dqio_mutex)
4934  *     down(dqio_mutex)                    jbd2_journal_start()
4935  *
4936  */
4937 
4938 #ifdef CONFIG_QUOTA
4939 
4940 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4941 {
4942 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4943 }
4944 
4945 static int ext4_write_dquot(struct dquot *dquot)
4946 {
4947 	int ret, err;
4948 	handle_t *handle;
4949 	struct inode *inode;
4950 
4951 	inode = dquot_to_inode(dquot);
4952 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4953 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4954 	if (IS_ERR(handle))
4955 		return PTR_ERR(handle);
4956 	ret = dquot_commit(dquot);
4957 	err = ext4_journal_stop(handle);
4958 	if (!ret)
4959 		ret = err;
4960 	return ret;
4961 }
4962 
4963 static int ext4_acquire_dquot(struct dquot *dquot)
4964 {
4965 	int ret, err;
4966 	handle_t *handle;
4967 
4968 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4969 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4970 	if (IS_ERR(handle))
4971 		return PTR_ERR(handle);
4972 	ret = dquot_acquire(dquot);
4973 	err = ext4_journal_stop(handle);
4974 	if (!ret)
4975 		ret = err;
4976 	return ret;
4977 }
4978 
4979 static int ext4_release_dquot(struct dquot *dquot)
4980 {
4981 	int ret, err;
4982 	handle_t *handle;
4983 
4984 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4985 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4986 	if (IS_ERR(handle)) {
4987 		/* Release dquot anyway to avoid endless cycle in dqput() */
4988 		dquot_release(dquot);
4989 		return PTR_ERR(handle);
4990 	}
4991 	ret = dquot_release(dquot);
4992 	err = ext4_journal_stop(handle);
4993 	if (!ret)
4994 		ret = err;
4995 	return ret;
4996 }
4997 
4998 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4999 {
5000 	struct super_block *sb = dquot->dq_sb;
5001 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5002 
5003 	/* Are we journaling quotas? */
5004 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5005 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5006 		dquot_mark_dquot_dirty(dquot);
5007 		return ext4_write_dquot(dquot);
5008 	} else {
5009 		return dquot_mark_dquot_dirty(dquot);
5010 	}
5011 }
5012 
5013 static int ext4_write_info(struct super_block *sb, int type)
5014 {
5015 	int ret, err;
5016 	handle_t *handle;
5017 
5018 	/* Data block + inode block */
5019 	handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5020 	if (IS_ERR(handle))
5021 		return PTR_ERR(handle);
5022 	ret = dquot_commit_info(sb, type);
5023 	err = ext4_journal_stop(handle);
5024 	if (!ret)
5025 		ret = err;
5026 	return ret;
5027 }
5028 
5029 /*
5030  * Turn on quotas during mount time - we need to find
5031  * the quota file and such...
5032  */
5033 static int ext4_quota_on_mount(struct super_block *sb, int type)
5034 {
5035 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5036 					EXT4_SB(sb)->s_jquota_fmt, type);
5037 }
5038 
5039 /*
5040  * Standard function to be called on quota_on
5041  */
5042 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5043 			 struct path *path)
5044 {
5045 	int err;
5046 
5047 	if (!test_opt(sb, QUOTA))
5048 		return -EINVAL;
5049 
5050 	/* Quotafile not on the same filesystem? */
5051 	if (path->dentry->d_sb != sb)
5052 		return -EXDEV;
5053 	/* Journaling quota? */
5054 	if (EXT4_SB(sb)->s_qf_names[type]) {
5055 		/* Quotafile not in fs root? */
5056 		if (path->dentry->d_parent != sb->s_root)
5057 			ext4_msg(sb, KERN_WARNING,
5058 				"Quota file not on filesystem root. "
5059 				"Journaled quota will not work");
5060 	}
5061 
5062 	/*
5063 	 * When we journal data on quota file, we have to flush journal to see
5064 	 * all updates to the file when we bypass pagecache...
5065 	 */
5066 	if (EXT4_SB(sb)->s_journal &&
5067 	    ext4_should_journal_data(path->dentry->d_inode)) {
5068 		/*
5069 		 * We don't need to lock updates but journal_flush() could
5070 		 * otherwise be livelocked...
5071 		 */
5072 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5073 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5074 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5075 		if (err)
5076 			return err;
5077 	}
5078 
5079 	return dquot_quota_on(sb, type, format_id, path);
5080 }
5081 
5082 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5083 			     unsigned int flags)
5084 {
5085 	int err;
5086 	struct inode *qf_inode;
5087 	unsigned long qf_inums[MAXQUOTAS] = {
5088 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5089 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5090 	};
5091 
5092 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5093 
5094 	if (!qf_inums[type])
5095 		return -EPERM;
5096 
5097 	qf_inode = ext4_iget(sb, qf_inums[type]);
5098 	if (IS_ERR(qf_inode)) {
5099 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5100 		return PTR_ERR(qf_inode);
5101 	}
5102 
5103 	/* Don't account quota for quota files to avoid recursion */
5104 	qf_inode->i_flags |= S_NOQUOTA;
5105 	err = dquot_enable(qf_inode, type, format_id, flags);
5106 	iput(qf_inode);
5107 
5108 	return err;
5109 }
5110 
5111 /* Enable usage tracking for all quota types. */
5112 static int ext4_enable_quotas(struct super_block *sb)
5113 {
5114 	int type, err = 0;
5115 	unsigned long qf_inums[MAXQUOTAS] = {
5116 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5117 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5118 	};
5119 
5120 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5121 	for (type = 0; type < MAXQUOTAS; type++) {
5122 		if (qf_inums[type]) {
5123 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5124 						DQUOT_USAGE_ENABLED);
5125 			if (err) {
5126 				ext4_warning(sb,
5127 					"Failed to enable quota tracking "
5128 					"(type=%d, err=%d). Please run "
5129 					"e2fsck to fix.", type, err);
5130 				return err;
5131 			}
5132 		}
5133 	}
5134 	return 0;
5135 }
5136 
5137 /*
5138  * quota_on function that is used when QUOTA feature is set.
5139  */
5140 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5141 				 int format_id)
5142 {
5143 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5144 		return -EINVAL;
5145 
5146 	/*
5147 	 * USAGE was enabled at mount time. Only need to enable LIMITS now.
5148 	 */
5149 	return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5150 }
5151 
5152 static int ext4_quota_off(struct super_block *sb, int type)
5153 {
5154 	struct inode *inode = sb_dqopt(sb)->files[type];
5155 	handle_t *handle;
5156 
5157 	/* Force all delayed allocation blocks to be allocated.
5158 	 * Caller already holds s_umount sem */
5159 	if (test_opt(sb, DELALLOC))
5160 		sync_filesystem(sb);
5161 
5162 	if (!inode)
5163 		goto out;
5164 
5165 	/* Update modification times of quota files when userspace can
5166 	 * start looking at them */
5167 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5168 	if (IS_ERR(handle))
5169 		goto out;
5170 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5171 	ext4_mark_inode_dirty(handle, inode);
5172 	ext4_journal_stop(handle);
5173 
5174 out:
5175 	return dquot_quota_off(sb, type);
5176 }
5177 
5178 /*
5179  * quota_off function that is used when QUOTA feature is set.
5180  */
5181 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5182 {
5183 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5184 		return -EINVAL;
5185 
5186 	/* Disable only the limits. */
5187 	return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5188 }
5189 
5190 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5191  * acquiring the locks... As quota files are never truncated and quota code
5192  * itself serializes the operations (and no one else should touch the files)
5193  * we don't have to be afraid of races */
5194 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5195 			       size_t len, loff_t off)
5196 {
5197 	struct inode *inode = sb_dqopt(sb)->files[type];
5198 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5199 	int err = 0;
5200 	int offset = off & (sb->s_blocksize - 1);
5201 	int tocopy;
5202 	size_t toread;
5203 	struct buffer_head *bh;
5204 	loff_t i_size = i_size_read(inode);
5205 
5206 	if (off > i_size)
5207 		return 0;
5208 	if (off+len > i_size)
5209 		len = i_size-off;
5210 	toread = len;
5211 	while (toread > 0) {
5212 		tocopy = sb->s_blocksize - offset < toread ?
5213 				sb->s_blocksize - offset : toread;
5214 		bh = ext4_bread(NULL, inode, blk, 0, &err);
5215 		if (err)
5216 			return err;
5217 		if (!bh)	/* A hole? */
5218 			memset(data, 0, tocopy);
5219 		else
5220 			memcpy(data, bh->b_data+offset, tocopy);
5221 		brelse(bh);
5222 		offset = 0;
5223 		toread -= tocopy;
5224 		data += tocopy;
5225 		blk++;
5226 	}
5227 	return len;
5228 }
5229 
5230 /* Write to quotafile (we know the transaction is already started and has
5231  * enough credits) */
5232 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5233 				const char *data, size_t len, loff_t off)
5234 {
5235 	struct inode *inode = sb_dqopt(sb)->files[type];
5236 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5237 	int err = 0;
5238 	int offset = off & (sb->s_blocksize - 1);
5239 	struct buffer_head *bh;
5240 	handle_t *handle = journal_current_handle();
5241 
5242 	if (EXT4_SB(sb)->s_journal && !handle) {
5243 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5244 			" cancelled because transaction is not started",
5245 			(unsigned long long)off, (unsigned long long)len);
5246 		return -EIO;
5247 	}
5248 	/*
5249 	 * Since we account only one data block in transaction credits,
5250 	 * then it is impossible to cross a block boundary.
5251 	 */
5252 	if (sb->s_blocksize - offset < len) {
5253 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5254 			" cancelled because not block aligned",
5255 			(unsigned long long)off, (unsigned long long)len);
5256 		return -EIO;
5257 	}
5258 
5259 	bh = ext4_bread(handle, inode, blk, 1, &err);
5260 	if (!bh)
5261 		goto out;
5262 	err = ext4_journal_get_write_access(handle, bh);
5263 	if (err) {
5264 		brelse(bh);
5265 		goto out;
5266 	}
5267 	lock_buffer(bh);
5268 	memcpy(bh->b_data+offset, data, len);
5269 	flush_dcache_page(bh->b_page);
5270 	unlock_buffer(bh);
5271 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5272 	brelse(bh);
5273 out:
5274 	if (err)
5275 		return err;
5276 	if (inode->i_size < off + len) {
5277 		i_size_write(inode, off + len);
5278 		EXT4_I(inode)->i_disksize = inode->i_size;
5279 		ext4_mark_inode_dirty(handle, inode);
5280 	}
5281 	return len;
5282 }
5283 
5284 #endif
5285 
5286 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5287 		       const char *dev_name, void *data)
5288 {
5289 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5290 }
5291 
5292 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5293 static inline void register_as_ext2(void)
5294 {
5295 	int err = register_filesystem(&ext2_fs_type);
5296 	if (err)
5297 		printk(KERN_WARNING
5298 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5299 }
5300 
5301 static inline void unregister_as_ext2(void)
5302 {
5303 	unregister_filesystem(&ext2_fs_type);
5304 }
5305 
5306 static inline int ext2_feature_set_ok(struct super_block *sb)
5307 {
5308 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5309 		return 0;
5310 	if (sb->s_flags & MS_RDONLY)
5311 		return 1;
5312 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5313 		return 0;
5314 	return 1;
5315 }
5316 #else
5317 static inline void register_as_ext2(void) { }
5318 static inline void unregister_as_ext2(void) { }
5319 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5320 #endif
5321 
5322 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5323 static inline void register_as_ext3(void)
5324 {
5325 	int err = register_filesystem(&ext3_fs_type);
5326 	if (err)
5327 		printk(KERN_WARNING
5328 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5329 }
5330 
5331 static inline void unregister_as_ext3(void)
5332 {
5333 	unregister_filesystem(&ext3_fs_type);
5334 }
5335 
5336 static inline int ext3_feature_set_ok(struct super_block *sb)
5337 {
5338 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5339 		return 0;
5340 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5341 		return 0;
5342 	if (sb->s_flags & MS_RDONLY)
5343 		return 1;
5344 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5345 		return 0;
5346 	return 1;
5347 }
5348 #else
5349 static inline void register_as_ext3(void) { }
5350 static inline void unregister_as_ext3(void) { }
5351 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5352 #endif
5353 
5354 static struct file_system_type ext4_fs_type = {
5355 	.owner		= THIS_MODULE,
5356 	.name		= "ext4",
5357 	.mount		= ext4_mount,
5358 	.kill_sb	= kill_block_super,
5359 	.fs_flags	= FS_REQUIRES_DEV,
5360 };
5361 MODULE_ALIAS_FS("ext4");
5362 
5363 static int __init ext4_init_feat_adverts(void)
5364 {
5365 	struct ext4_features *ef;
5366 	int ret = -ENOMEM;
5367 
5368 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5369 	if (!ef)
5370 		goto out;
5371 
5372 	ef->f_kobj.kset = ext4_kset;
5373 	init_completion(&ef->f_kobj_unregister);
5374 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5375 				   "features");
5376 	if (ret) {
5377 		kfree(ef);
5378 		goto out;
5379 	}
5380 
5381 	ext4_feat = ef;
5382 	ret = 0;
5383 out:
5384 	return ret;
5385 }
5386 
5387 static void ext4_exit_feat_adverts(void)
5388 {
5389 	kobject_put(&ext4_feat->f_kobj);
5390 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5391 	kfree(ext4_feat);
5392 }
5393 
5394 /* Shared across all ext4 file systems */
5395 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5396 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5397 
5398 static int __init ext4_init_fs(void)
5399 {
5400 	int i, err;
5401 
5402 	ext4_li_info = NULL;
5403 	mutex_init(&ext4_li_mtx);
5404 
5405 	/* Build-time check for flags consistency */
5406 	ext4_check_flag_values();
5407 
5408 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5409 		mutex_init(&ext4__aio_mutex[i]);
5410 		init_waitqueue_head(&ext4__ioend_wq[i]);
5411 	}
5412 
5413 	err = ext4_init_es();
5414 	if (err)
5415 		return err;
5416 
5417 	err = ext4_init_pageio();
5418 	if (err)
5419 		goto out7;
5420 
5421 	err = ext4_init_system_zone();
5422 	if (err)
5423 		goto out6;
5424 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5425 	if (!ext4_kset) {
5426 		err = -ENOMEM;
5427 		goto out5;
5428 	}
5429 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5430 
5431 	err = ext4_init_feat_adverts();
5432 	if (err)
5433 		goto out4;
5434 
5435 	err = ext4_init_mballoc();
5436 	if (err)
5437 		goto out3;
5438 
5439 	err = ext4_init_xattr();
5440 	if (err)
5441 		goto out2;
5442 	err = init_inodecache();
5443 	if (err)
5444 		goto out1;
5445 	register_as_ext3();
5446 	register_as_ext2();
5447 	err = register_filesystem(&ext4_fs_type);
5448 	if (err)
5449 		goto out;
5450 
5451 	return 0;
5452 out:
5453 	unregister_as_ext2();
5454 	unregister_as_ext3();
5455 	destroy_inodecache();
5456 out1:
5457 	ext4_exit_xattr();
5458 out2:
5459 	ext4_exit_mballoc();
5460 out3:
5461 	ext4_exit_feat_adverts();
5462 out4:
5463 	if (ext4_proc_root)
5464 		remove_proc_entry("fs/ext4", NULL);
5465 	kset_unregister(ext4_kset);
5466 out5:
5467 	ext4_exit_system_zone();
5468 out6:
5469 	ext4_exit_pageio();
5470 out7:
5471 	ext4_exit_es();
5472 
5473 	return err;
5474 }
5475 
5476 static void __exit ext4_exit_fs(void)
5477 {
5478 	ext4_destroy_lazyinit_thread();
5479 	unregister_as_ext2();
5480 	unregister_as_ext3();
5481 	unregister_filesystem(&ext4_fs_type);
5482 	destroy_inodecache();
5483 	ext4_exit_xattr();
5484 	ext4_exit_mballoc();
5485 	ext4_exit_feat_adverts();
5486 	remove_proc_entry("fs/ext4", NULL);
5487 	kset_unregister(ext4_kset);
5488 	ext4_exit_system_zone();
5489 	ext4_exit_pageio();
5490 }
5491 
5492 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5493 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5494 MODULE_LICENSE("GPL");
5495 module_init(ext4_init_fs)
5496 module_exit(ext4_exit_fs)
5497