xref: /openbmc/linux/fs/ext4/super.c (revision 62e7ca52)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/jbd2.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/parser.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/proc_fs.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/cleancache.h>
42 #include <asm/uaccess.h>
43 
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46 
47 #include "ext4.h"
48 #include "ext4_extents.h"	/* Needed for trace points definition */
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/ext4.h>
56 
57 static struct proc_dir_entry *ext4_proc_root;
58 static struct kset *ext4_kset;
59 static struct ext4_lazy_init *ext4_li_info;
60 static struct mutex ext4_li_mtx;
61 static struct ext4_features *ext4_feat;
62 static int ext4_mballoc_ready;
63 
64 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
65 			     unsigned long journal_devnum);
66 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
67 static int ext4_commit_super(struct super_block *sb, int sync);
68 static void ext4_mark_recovery_complete(struct super_block *sb,
69 					struct ext4_super_block *es);
70 static void ext4_clear_journal_err(struct super_block *sb,
71 				   struct ext4_super_block *es);
72 static int ext4_sync_fs(struct super_block *sb, int wait);
73 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait);
74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
76 static int ext4_unfreeze(struct super_block *sb);
77 static int ext4_freeze(struct super_block *sb);
78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
79 		       const char *dev_name, void *data);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
83 static void ext4_destroy_lazyinit_thread(void);
84 static void ext4_unregister_li_request(struct super_block *sb);
85 static void ext4_clear_request_list(void);
86 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
87 
88 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
89 static struct file_system_type ext2_fs_type = {
90 	.owner		= THIS_MODULE,
91 	.name		= "ext2",
92 	.mount		= ext4_mount,
93 	.kill_sb	= kill_block_super,
94 	.fs_flags	= FS_REQUIRES_DEV,
95 };
96 MODULE_ALIAS_FS("ext2");
97 MODULE_ALIAS("ext2");
98 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
99 #else
100 #define IS_EXT2_SB(sb) (0)
101 #endif
102 
103 
104 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
105 static struct file_system_type ext3_fs_type = {
106 	.owner		= THIS_MODULE,
107 	.name		= "ext3",
108 	.mount		= ext4_mount,
109 	.kill_sb	= kill_block_super,
110 	.fs_flags	= FS_REQUIRES_DEV,
111 };
112 MODULE_ALIAS_FS("ext3");
113 MODULE_ALIAS("ext3");
114 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
115 #else
116 #define IS_EXT3_SB(sb) (0)
117 #endif
118 
119 static int ext4_verify_csum_type(struct super_block *sb,
120 				 struct ext4_super_block *es)
121 {
122 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
123 					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
124 		return 1;
125 
126 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
127 }
128 
129 static __le32 ext4_superblock_csum(struct super_block *sb,
130 				   struct ext4_super_block *es)
131 {
132 	struct ext4_sb_info *sbi = EXT4_SB(sb);
133 	int offset = offsetof(struct ext4_super_block, s_checksum);
134 	__u32 csum;
135 
136 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
137 
138 	return cpu_to_le32(csum);
139 }
140 
141 static int ext4_superblock_csum_verify(struct super_block *sb,
142 				       struct ext4_super_block *es)
143 {
144 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
145 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
146 		return 1;
147 
148 	return es->s_checksum == ext4_superblock_csum(sb, es);
149 }
150 
151 void ext4_superblock_csum_set(struct super_block *sb)
152 {
153 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
154 
155 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
156 		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
157 		return;
158 
159 	es->s_checksum = ext4_superblock_csum(sb, es);
160 }
161 
162 void *ext4_kvmalloc(size_t size, gfp_t flags)
163 {
164 	void *ret;
165 
166 	ret = kmalloc(size, flags | __GFP_NOWARN);
167 	if (!ret)
168 		ret = __vmalloc(size, flags, PAGE_KERNEL);
169 	return ret;
170 }
171 
172 void *ext4_kvzalloc(size_t size, gfp_t flags)
173 {
174 	void *ret;
175 
176 	ret = kzalloc(size, flags | __GFP_NOWARN);
177 	if (!ret)
178 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
179 	return ret;
180 }
181 
182 void ext4_kvfree(void *ptr)
183 {
184 	if (is_vmalloc_addr(ptr))
185 		vfree(ptr);
186 	else
187 		kfree(ptr);
188 
189 }
190 
191 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
192 			       struct ext4_group_desc *bg)
193 {
194 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
195 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
196 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
197 }
198 
199 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
200 			       struct ext4_group_desc *bg)
201 {
202 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
203 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
204 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
205 }
206 
207 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
208 			      struct ext4_group_desc *bg)
209 {
210 	return le32_to_cpu(bg->bg_inode_table_lo) |
211 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
212 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
213 }
214 
215 __u32 ext4_free_group_clusters(struct super_block *sb,
216 			       struct ext4_group_desc *bg)
217 {
218 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
219 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
220 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
221 }
222 
223 __u32 ext4_free_inodes_count(struct super_block *sb,
224 			      struct ext4_group_desc *bg)
225 {
226 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
227 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
228 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
229 }
230 
231 __u32 ext4_used_dirs_count(struct super_block *sb,
232 			      struct ext4_group_desc *bg)
233 {
234 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
235 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
236 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
237 }
238 
239 __u32 ext4_itable_unused_count(struct super_block *sb,
240 			      struct ext4_group_desc *bg)
241 {
242 	return le16_to_cpu(bg->bg_itable_unused_lo) |
243 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
244 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
245 }
246 
247 void ext4_block_bitmap_set(struct super_block *sb,
248 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
249 {
250 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
251 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
252 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
253 }
254 
255 void ext4_inode_bitmap_set(struct super_block *sb,
256 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
257 {
258 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
259 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
260 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
261 }
262 
263 void ext4_inode_table_set(struct super_block *sb,
264 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
265 {
266 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
267 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
268 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
269 }
270 
271 void ext4_free_group_clusters_set(struct super_block *sb,
272 				  struct ext4_group_desc *bg, __u32 count)
273 {
274 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
275 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
276 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
277 }
278 
279 void ext4_free_inodes_set(struct super_block *sb,
280 			  struct ext4_group_desc *bg, __u32 count)
281 {
282 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
283 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
284 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
285 }
286 
287 void ext4_used_dirs_set(struct super_block *sb,
288 			  struct ext4_group_desc *bg, __u32 count)
289 {
290 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
291 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
292 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
293 }
294 
295 void ext4_itable_unused_set(struct super_block *sb,
296 			  struct ext4_group_desc *bg, __u32 count)
297 {
298 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
299 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
300 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
301 }
302 
303 
304 static void __save_error_info(struct super_block *sb, const char *func,
305 			    unsigned int line)
306 {
307 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
308 
309 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
310 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
311 	es->s_last_error_time = cpu_to_le32(get_seconds());
312 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
313 	es->s_last_error_line = cpu_to_le32(line);
314 	if (!es->s_first_error_time) {
315 		es->s_first_error_time = es->s_last_error_time;
316 		strncpy(es->s_first_error_func, func,
317 			sizeof(es->s_first_error_func));
318 		es->s_first_error_line = cpu_to_le32(line);
319 		es->s_first_error_ino = es->s_last_error_ino;
320 		es->s_first_error_block = es->s_last_error_block;
321 	}
322 	/*
323 	 * Start the daily error reporting function if it hasn't been
324 	 * started already
325 	 */
326 	if (!es->s_error_count)
327 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
328 	le32_add_cpu(&es->s_error_count, 1);
329 }
330 
331 static void save_error_info(struct super_block *sb, const char *func,
332 			    unsigned int line)
333 {
334 	__save_error_info(sb, func, line);
335 	ext4_commit_super(sb, 1);
336 }
337 
338 /*
339  * The del_gendisk() function uninitializes the disk-specific data
340  * structures, including the bdi structure, without telling anyone
341  * else.  Once this happens, any attempt to call mark_buffer_dirty()
342  * (for example, by ext4_commit_super), will cause a kernel OOPS.
343  * This is a kludge to prevent these oops until we can put in a proper
344  * hook in del_gendisk() to inform the VFS and file system layers.
345  */
346 static int block_device_ejected(struct super_block *sb)
347 {
348 	struct inode *bd_inode = sb->s_bdev->bd_inode;
349 	struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
350 
351 	return bdi->dev == NULL;
352 }
353 
354 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
355 {
356 	struct super_block		*sb = journal->j_private;
357 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
358 	int				error = is_journal_aborted(journal);
359 	struct ext4_journal_cb_entry	*jce;
360 
361 	BUG_ON(txn->t_state == T_FINISHED);
362 	spin_lock(&sbi->s_md_lock);
363 	while (!list_empty(&txn->t_private_list)) {
364 		jce = list_entry(txn->t_private_list.next,
365 				 struct ext4_journal_cb_entry, jce_list);
366 		list_del_init(&jce->jce_list);
367 		spin_unlock(&sbi->s_md_lock);
368 		jce->jce_func(sb, jce, error);
369 		spin_lock(&sbi->s_md_lock);
370 	}
371 	spin_unlock(&sbi->s_md_lock);
372 }
373 
374 /* Deal with the reporting of failure conditions on a filesystem such as
375  * inconsistencies detected or read IO failures.
376  *
377  * On ext2, we can store the error state of the filesystem in the
378  * superblock.  That is not possible on ext4, because we may have other
379  * write ordering constraints on the superblock which prevent us from
380  * writing it out straight away; and given that the journal is about to
381  * be aborted, we can't rely on the current, or future, transactions to
382  * write out the superblock safely.
383  *
384  * We'll just use the jbd2_journal_abort() error code to record an error in
385  * the journal instead.  On recovery, the journal will complain about
386  * that error until we've noted it down and cleared it.
387  */
388 
389 static void ext4_handle_error(struct super_block *sb)
390 {
391 	if (sb->s_flags & MS_RDONLY)
392 		return;
393 
394 	if (!test_opt(sb, ERRORS_CONT)) {
395 		journal_t *journal = EXT4_SB(sb)->s_journal;
396 
397 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
398 		if (journal)
399 			jbd2_journal_abort(journal, -EIO);
400 	}
401 	if (test_opt(sb, ERRORS_RO)) {
402 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
403 		/*
404 		 * Make sure updated value of ->s_mount_flags will be visible
405 		 * before ->s_flags update
406 		 */
407 		smp_wmb();
408 		sb->s_flags |= MS_RDONLY;
409 	}
410 	if (test_opt(sb, ERRORS_PANIC))
411 		panic("EXT4-fs (device %s): panic forced after error\n",
412 			sb->s_id);
413 }
414 
415 #define ext4_error_ratelimit(sb)					\
416 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
417 			     "EXT4-fs error")
418 
419 void __ext4_error(struct super_block *sb, const char *function,
420 		  unsigned int line, const char *fmt, ...)
421 {
422 	struct va_format vaf;
423 	va_list args;
424 
425 	if (ext4_error_ratelimit(sb)) {
426 		va_start(args, fmt);
427 		vaf.fmt = fmt;
428 		vaf.va = &args;
429 		printk(KERN_CRIT
430 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
431 		       sb->s_id, function, line, current->comm, &vaf);
432 		va_end(args);
433 	}
434 	save_error_info(sb, function, line);
435 	ext4_handle_error(sb);
436 }
437 
438 void __ext4_error_inode(struct inode *inode, const char *function,
439 			unsigned int line, ext4_fsblk_t block,
440 			const char *fmt, ...)
441 {
442 	va_list args;
443 	struct va_format vaf;
444 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
445 
446 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
447 	es->s_last_error_block = cpu_to_le64(block);
448 	if (ext4_error_ratelimit(inode->i_sb)) {
449 		va_start(args, fmt);
450 		vaf.fmt = fmt;
451 		vaf.va = &args;
452 		if (block)
453 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
454 			       "inode #%lu: block %llu: comm %s: %pV\n",
455 			       inode->i_sb->s_id, function, line, inode->i_ino,
456 			       block, current->comm, &vaf);
457 		else
458 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
459 			       "inode #%lu: comm %s: %pV\n",
460 			       inode->i_sb->s_id, function, line, inode->i_ino,
461 			       current->comm, &vaf);
462 		va_end(args);
463 	}
464 	save_error_info(inode->i_sb, function, line);
465 	ext4_handle_error(inode->i_sb);
466 }
467 
468 void __ext4_error_file(struct file *file, const char *function,
469 		       unsigned int line, ext4_fsblk_t block,
470 		       const char *fmt, ...)
471 {
472 	va_list args;
473 	struct va_format vaf;
474 	struct ext4_super_block *es;
475 	struct inode *inode = file_inode(file);
476 	char pathname[80], *path;
477 
478 	es = EXT4_SB(inode->i_sb)->s_es;
479 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
480 	if (ext4_error_ratelimit(inode->i_sb)) {
481 		path = d_path(&(file->f_path), pathname, sizeof(pathname));
482 		if (IS_ERR(path))
483 			path = "(unknown)";
484 		va_start(args, fmt);
485 		vaf.fmt = fmt;
486 		vaf.va = &args;
487 		if (block)
488 			printk(KERN_CRIT
489 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
490 			       "block %llu: comm %s: path %s: %pV\n",
491 			       inode->i_sb->s_id, function, line, inode->i_ino,
492 			       block, current->comm, path, &vaf);
493 		else
494 			printk(KERN_CRIT
495 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
496 			       "comm %s: path %s: %pV\n",
497 			       inode->i_sb->s_id, function, line, inode->i_ino,
498 			       current->comm, path, &vaf);
499 		va_end(args);
500 	}
501 	save_error_info(inode->i_sb, function, line);
502 	ext4_handle_error(inode->i_sb);
503 }
504 
505 const char *ext4_decode_error(struct super_block *sb, int errno,
506 			      char nbuf[16])
507 {
508 	char *errstr = NULL;
509 
510 	switch (errno) {
511 	case -EIO:
512 		errstr = "IO failure";
513 		break;
514 	case -ENOMEM:
515 		errstr = "Out of memory";
516 		break;
517 	case -EROFS:
518 		if (!sb || (EXT4_SB(sb)->s_journal &&
519 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
520 			errstr = "Journal has aborted";
521 		else
522 			errstr = "Readonly filesystem";
523 		break;
524 	default:
525 		/* If the caller passed in an extra buffer for unknown
526 		 * errors, textualise them now.  Else we just return
527 		 * NULL. */
528 		if (nbuf) {
529 			/* Check for truncated error codes... */
530 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
531 				errstr = nbuf;
532 		}
533 		break;
534 	}
535 
536 	return errstr;
537 }
538 
539 /* __ext4_std_error decodes expected errors from journaling functions
540  * automatically and invokes the appropriate error response.  */
541 
542 void __ext4_std_error(struct super_block *sb, const char *function,
543 		      unsigned int line, int errno)
544 {
545 	char nbuf[16];
546 	const char *errstr;
547 
548 	/* Special case: if the error is EROFS, and we're not already
549 	 * inside a transaction, then there's really no point in logging
550 	 * an error. */
551 	if (errno == -EROFS && journal_current_handle() == NULL &&
552 	    (sb->s_flags & MS_RDONLY))
553 		return;
554 
555 	if (ext4_error_ratelimit(sb)) {
556 		errstr = ext4_decode_error(sb, errno, nbuf);
557 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
558 		       sb->s_id, function, line, errstr);
559 	}
560 
561 	save_error_info(sb, function, line);
562 	ext4_handle_error(sb);
563 }
564 
565 /*
566  * ext4_abort is a much stronger failure handler than ext4_error.  The
567  * abort function may be used to deal with unrecoverable failures such
568  * as journal IO errors or ENOMEM at a critical moment in log management.
569  *
570  * We unconditionally force the filesystem into an ABORT|READONLY state,
571  * unless the error response on the fs has been set to panic in which
572  * case we take the easy way out and panic immediately.
573  */
574 
575 void __ext4_abort(struct super_block *sb, const char *function,
576 		unsigned int line, const char *fmt, ...)
577 {
578 	va_list args;
579 
580 	save_error_info(sb, function, line);
581 	va_start(args, fmt);
582 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
583 	       function, line);
584 	vprintk(fmt, args);
585 	printk("\n");
586 	va_end(args);
587 
588 	if ((sb->s_flags & MS_RDONLY) == 0) {
589 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
590 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
591 		/*
592 		 * Make sure updated value of ->s_mount_flags will be visible
593 		 * before ->s_flags update
594 		 */
595 		smp_wmb();
596 		sb->s_flags |= MS_RDONLY;
597 		if (EXT4_SB(sb)->s_journal)
598 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
599 		save_error_info(sb, function, line);
600 	}
601 	if (test_opt(sb, ERRORS_PANIC))
602 		panic("EXT4-fs panic from previous error\n");
603 }
604 
605 void __ext4_msg(struct super_block *sb,
606 		const char *prefix, const char *fmt, ...)
607 {
608 	struct va_format vaf;
609 	va_list args;
610 
611 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
612 		return;
613 
614 	va_start(args, fmt);
615 	vaf.fmt = fmt;
616 	vaf.va = &args;
617 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
618 	va_end(args);
619 }
620 
621 void __ext4_warning(struct super_block *sb, const char *function,
622 		    unsigned int line, const char *fmt, ...)
623 {
624 	struct va_format vaf;
625 	va_list args;
626 
627 	if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
628 			  "EXT4-fs warning"))
629 		return;
630 
631 	va_start(args, fmt);
632 	vaf.fmt = fmt;
633 	vaf.va = &args;
634 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
635 	       sb->s_id, function, line, &vaf);
636 	va_end(args);
637 }
638 
639 void __ext4_grp_locked_error(const char *function, unsigned int line,
640 			     struct super_block *sb, ext4_group_t grp,
641 			     unsigned long ino, ext4_fsblk_t block,
642 			     const char *fmt, ...)
643 __releases(bitlock)
644 __acquires(bitlock)
645 {
646 	struct va_format vaf;
647 	va_list args;
648 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
649 
650 	es->s_last_error_ino = cpu_to_le32(ino);
651 	es->s_last_error_block = cpu_to_le64(block);
652 	__save_error_info(sb, function, line);
653 
654 	if (ext4_error_ratelimit(sb)) {
655 		va_start(args, fmt);
656 		vaf.fmt = fmt;
657 		vaf.va = &args;
658 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
659 		       sb->s_id, function, line, grp);
660 		if (ino)
661 			printk(KERN_CONT "inode %lu: ", ino);
662 		if (block)
663 			printk(KERN_CONT "block %llu:",
664 			       (unsigned long long) block);
665 		printk(KERN_CONT "%pV\n", &vaf);
666 		va_end(args);
667 	}
668 
669 	if (test_opt(sb, ERRORS_CONT)) {
670 		ext4_commit_super(sb, 0);
671 		return;
672 	}
673 
674 	ext4_unlock_group(sb, grp);
675 	ext4_handle_error(sb);
676 	/*
677 	 * We only get here in the ERRORS_RO case; relocking the group
678 	 * may be dangerous, but nothing bad will happen since the
679 	 * filesystem will have already been marked read/only and the
680 	 * journal has been aborted.  We return 1 as a hint to callers
681 	 * who might what to use the return value from
682 	 * ext4_grp_locked_error() to distinguish between the
683 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
684 	 * aggressively from the ext4 function in question, with a
685 	 * more appropriate error code.
686 	 */
687 	ext4_lock_group(sb, grp);
688 	return;
689 }
690 
691 void ext4_update_dynamic_rev(struct super_block *sb)
692 {
693 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
694 
695 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
696 		return;
697 
698 	ext4_warning(sb,
699 		     "updating to rev %d because of new feature flag, "
700 		     "running e2fsck is recommended",
701 		     EXT4_DYNAMIC_REV);
702 
703 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
704 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
705 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
706 	/* leave es->s_feature_*compat flags alone */
707 	/* es->s_uuid will be set by e2fsck if empty */
708 
709 	/*
710 	 * The rest of the superblock fields should be zero, and if not it
711 	 * means they are likely already in use, so leave them alone.  We
712 	 * can leave it up to e2fsck to clean up any inconsistencies there.
713 	 */
714 }
715 
716 /*
717  * Open the external journal device
718  */
719 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
720 {
721 	struct block_device *bdev;
722 	char b[BDEVNAME_SIZE];
723 
724 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
725 	if (IS_ERR(bdev))
726 		goto fail;
727 	return bdev;
728 
729 fail:
730 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
731 			__bdevname(dev, b), PTR_ERR(bdev));
732 	return NULL;
733 }
734 
735 /*
736  * Release the journal device
737  */
738 static void ext4_blkdev_put(struct block_device *bdev)
739 {
740 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
741 }
742 
743 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
744 {
745 	struct block_device *bdev;
746 	bdev = sbi->journal_bdev;
747 	if (bdev) {
748 		ext4_blkdev_put(bdev);
749 		sbi->journal_bdev = NULL;
750 	}
751 }
752 
753 static inline struct inode *orphan_list_entry(struct list_head *l)
754 {
755 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
756 }
757 
758 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
759 {
760 	struct list_head *l;
761 
762 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
763 		 le32_to_cpu(sbi->s_es->s_last_orphan));
764 
765 	printk(KERN_ERR "sb_info orphan list:\n");
766 	list_for_each(l, &sbi->s_orphan) {
767 		struct inode *inode = orphan_list_entry(l);
768 		printk(KERN_ERR "  "
769 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
770 		       inode->i_sb->s_id, inode->i_ino, inode,
771 		       inode->i_mode, inode->i_nlink,
772 		       NEXT_ORPHAN(inode));
773 	}
774 }
775 
776 static void ext4_put_super(struct super_block *sb)
777 {
778 	struct ext4_sb_info *sbi = EXT4_SB(sb);
779 	struct ext4_super_block *es = sbi->s_es;
780 	int i, err;
781 
782 	ext4_unregister_li_request(sb);
783 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
784 
785 	flush_workqueue(sbi->rsv_conversion_wq);
786 	destroy_workqueue(sbi->rsv_conversion_wq);
787 
788 	if (sbi->s_journal) {
789 		err = jbd2_journal_destroy(sbi->s_journal);
790 		sbi->s_journal = NULL;
791 		if (err < 0)
792 			ext4_abort(sb, "Couldn't clean up the journal");
793 	}
794 
795 	ext4_es_unregister_shrinker(sbi);
796 	del_timer_sync(&sbi->s_err_report);
797 	ext4_release_system_zone(sb);
798 	ext4_mb_release(sb);
799 	ext4_ext_release(sb);
800 	ext4_xattr_put_super(sb);
801 
802 	if (!(sb->s_flags & MS_RDONLY)) {
803 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
804 		es->s_state = cpu_to_le16(sbi->s_mount_state);
805 	}
806 	if (!(sb->s_flags & MS_RDONLY))
807 		ext4_commit_super(sb, 1);
808 
809 	if (sbi->s_proc) {
810 		remove_proc_entry("options", sbi->s_proc);
811 		remove_proc_entry(sb->s_id, ext4_proc_root);
812 	}
813 	kobject_del(&sbi->s_kobj);
814 
815 	for (i = 0; i < sbi->s_gdb_count; i++)
816 		brelse(sbi->s_group_desc[i]);
817 	ext4_kvfree(sbi->s_group_desc);
818 	ext4_kvfree(sbi->s_flex_groups);
819 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
820 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
821 	percpu_counter_destroy(&sbi->s_dirs_counter);
822 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
823 	percpu_counter_destroy(&sbi->s_extent_cache_cnt);
824 	brelse(sbi->s_sbh);
825 #ifdef CONFIG_QUOTA
826 	for (i = 0; i < MAXQUOTAS; i++)
827 		kfree(sbi->s_qf_names[i]);
828 #endif
829 
830 	/* Debugging code just in case the in-memory inode orphan list
831 	 * isn't empty.  The on-disk one can be non-empty if we've
832 	 * detected an error and taken the fs readonly, but the
833 	 * in-memory list had better be clean by this point. */
834 	if (!list_empty(&sbi->s_orphan))
835 		dump_orphan_list(sb, sbi);
836 	J_ASSERT(list_empty(&sbi->s_orphan));
837 
838 	invalidate_bdev(sb->s_bdev);
839 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
840 		/*
841 		 * Invalidate the journal device's buffers.  We don't want them
842 		 * floating about in memory - the physical journal device may
843 		 * hotswapped, and it breaks the `ro-after' testing code.
844 		 */
845 		sync_blockdev(sbi->journal_bdev);
846 		invalidate_bdev(sbi->journal_bdev);
847 		ext4_blkdev_remove(sbi);
848 	}
849 	if (sbi->s_mb_cache) {
850 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
851 		sbi->s_mb_cache = NULL;
852 	}
853 	if (sbi->s_mmp_tsk)
854 		kthread_stop(sbi->s_mmp_tsk);
855 	sb->s_fs_info = NULL;
856 	/*
857 	 * Now that we are completely done shutting down the
858 	 * superblock, we need to actually destroy the kobject.
859 	 */
860 	kobject_put(&sbi->s_kobj);
861 	wait_for_completion(&sbi->s_kobj_unregister);
862 	if (sbi->s_chksum_driver)
863 		crypto_free_shash(sbi->s_chksum_driver);
864 	kfree(sbi->s_blockgroup_lock);
865 	kfree(sbi);
866 }
867 
868 static struct kmem_cache *ext4_inode_cachep;
869 
870 /*
871  * Called inside transaction, so use GFP_NOFS
872  */
873 static struct inode *ext4_alloc_inode(struct super_block *sb)
874 {
875 	struct ext4_inode_info *ei;
876 
877 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
878 	if (!ei)
879 		return NULL;
880 
881 	ei->vfs_inode.i_version = 1;
882 	spin_lock_init(&ei->i_raw_lock);
883 	INIT_LIST_HEAD(&ei->i_prealloc_list);
884 	spin_lock_init(&ei->i_prealloc_lock);
885 	ext4_es_init_tree(&ei->i_es_tree);
886 	rwlock_init(&ei->i_es_lock);
887 	INIT_LIST_HEAD(&ei->i_es_lru);
888 	ei->i_es_lru_nr = 0;
889 	ei->i_touch_when = 0;
890 	ei->i_reserved_data_blocks = 0;
891 	ei->i_reserved_meta_blocks = 0;
892 	ei->i_allocated_meta_blocks = 0;
893 	ei->i_da_metadata_calc_len = 0;
894 	ei->i_da_metadata_calc_last_lblock = 0;
895 	spin_lock_init(&(ei->i_block_reservation_lock));
896 #ifdef CONFIG_QUOTA
897 	ei->i_reserved_quota = 0;
898 #endif
899 	ei->jinode = NULL;
900 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
901 	spin_lock_init(&ei->i_completed_io_lock);
902 	ei->i_sync_tid = 0;
903 	ei->i_datasync_tid = 0;
904 	atomic_set(&ei->i_ioend_count, 0);
905 	atomic_set(&ei->i_unwritten, 0);
906 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
907 
908 	return &ei->vfs_inode;
909 }
910 
911 static int ext4_drop_inode(struct inode *inode)
912 {
913 	int drop = generic_drop_inode(inode);
914 
915 	trace_ext4_drop_inode(inode, drop);
916 	return drop;
917 }
918 
919 static void ext4_i_callback(struct rcu_head *head)
920 {
921 	struct inode *inode = container_of(head, struct inode, i_rcu);
922 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
923 }
924 
925 static void ext4_destroy_inode(struct inode *inode)
926 {
927 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
928 		ext4_msg(inode->i_sb, KERN_ERR,
929 			 "Inode %lu (%p): orphan list check failed!",
930 			 inode->i_ino, EXT4_I(inode));
931 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
932 				EXT4_I(inode), sizeof(struct ext4_inode_info),
933 				true);
934 		dump_stack();
935 	}
936 	call_rcu(&inode->i_rcu, ext4_i_callback);
937 }
938 
939 static void init_once(void *foo)
940 {
941 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
942 
943 	INIT_LIST_HEAD(&ei->i_orphan);
944 	init_rwsem(&ei->xattr_sem);
945 	init_rwsem(&ei->i_data_sem);
946 	inode_init_once(&ei->vfs_inode);
947 }
948 
949 static int __init init_inodecache(void)
950 {
951 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
952 					     sizeof(struct ext4_inode_info),
953 					     0, (SLAB_RECLAIM_ACCOUNT|
954 						SLAB_MEM_SPREAD),
955 					     init_once);
956 	if (ext4_inode_cachep == NULL)
957 		return -ENOMEM;
958 	return 0;
959 }
960 
961 static void destroy_inodecache(void)
962 {
963 	/*
964 	 * Make sure all delayed rcu free inodes are flushed before we
965 	 * destroy cache.
966 	 */
967 	rcu_barrier();
968 	kmem_cache_destroy(ext4_inode_cachep);
969 }
970 
971 void ext4_clear_inode(struct inode *inode)
972 {
973 	invalidate_inode_buffers(inode);
974 	clear_inode(inode);
975 	dquot_drop(inode);
976 	ext4_discard_preallocations(inode);
977 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
978 	ext4_es_lru_del(inode);
979 	if (EXT4_I(inode)->jinode) {
980 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
981 					       EXT4_I(inode)->jinode);
982 		jbd2_free_inode(EXT4_I(inode)->jinode);
983 		EXT4_I(inode)->jinode = NULL;
984 	}
985 }
986 
987 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
988 					u64 ino, u32 generation)
989 {
990 	struct inode *inode;
991 
992 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
993 		return ERR_PTR(-ESTALE);
994 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
995 		return ERR_PTR(-ESTALE);
996 
997 	/* iget isn't really right if the inode is currently unallocated!!
998 	 *
999 	 * ext4_read_inode will return a bad_inode if the inode had been
1000 	 * deleted, so we should be safe.
1001 	 *
1002 	 * Currently we don't know the generation for parent directory, so
1003 	 * a generation of 0 means "accept any"
1004 	 */
1005 	inode = ext4_iget(sb, ino);
1006 	if (IS_ERR(inode))
1007 		return ERR_CAST(inode);
1008 	if (generation && inode->i_generation != generation) {
1009 		iput(inode);
1010 		return ERR_PTR(-ESTALE);
1011 	}
1012 
1013 	return inode;
1014 }
1015 
1016 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1017 					int fh_len, int fh_type)
1018 {
1019 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1020 				    ext4_nfs_get_inode);
1021 }
1022 
1023 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1024 					int fh_len, int fh_type)
1025 {
1026 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1027 				    ext4_nfs_get_inode);
1028 }
1029 
1030 /*
1031  * Try to release metadata pages (indirect blocks, directories) which are
1032  * mapped via the block device.  Since these pages could have journal heads
1033  * which would prevent try_to_free_buffers() from freeing them, we must use
1034  * jbd2 layer's try_to_free_buffers() function to release them.
1035  */
1036 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1037 				 gfp_t wait)
1038 {
1039 	journal_t *journal = EXT4_SB(sb)->s_journal;
1040 
1041 	WARN_ON(PageChecked(page));
1042 	if (!page_has_buffers(page))
1043 		return 0;
1044 	if (journal)
1045 		return jbd2_journal_try_to_free_buffers(journal, page,
1046 							wait & ~__GFP_WAIT);
1047 	return try_to_free_buffers(page);
1048 }
1049 
1050 #ifdef CONFIG_QUOTA
1051 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1052 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1053 
1054 static int ext4_write_dquot(struct dquot *dquot);
1055 static int ext4_acquire_dquot(struct dquot *dquot);
1056 static int ext4_release_dquot(struct dquot *dquot);
1057 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1058 static int ext4_write_info(struct super_block *sb, int type);
1059 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1060 			 struct path *path);
1061 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1062 				 int format_id);
1063 static int ext4_quota_off(struct super_block *sb, int type);
1064 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1065 static int ext4_quota_on_mount(struct super_block *sb, int type);
1066 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1067 			       size_t len, loff_t off);
1068 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1069 				const char *data, size_t len, loff_t off);
1070 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1071 			     unsigned int flags);
1072 static int ext4_enable_quotas(struct super_block *sb);
1073 
1074 static const struct dquot_operations ext4_quota_operations = {
1075 	.get_reserved_space = ext4_get_reserved_space,
1076 	.write_dquot	= ext4_write_dquot,
1077 	.acquire_dquot	= ext4_acquire_dquot,
1078 	.release_dquot	= ext4_release_dquot,
1079 	.mark_dirty	= ext4_mark_dquot_dirty,
1080 	.write_info	= ext4_write_info,
1081 	.alloc_dquot	= dquot_alloc,
1082 	.destroy_dquot	= dquot_destroy,
1083 };
1084 
1085 static const struct quotactl_ops ext4_qctl_operations = {
1086 	.quota_on	= ext4_quota_on,
1087 	.quota_off	= ext4_quota_off,
1088 	.quota_sync	= dquot_quota_sync,
1089 	.get_info	= dquot_get_dqinfo,
1090 	.set_info	= dquot_set_dqinfo,
1091 	.get_dqblk	= dquot_get_dqblk,
1092 	.set_dqblk	= dquot_set_dqblk
1093 };
1094 
1095 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1096 	.quota_on_meta	= ext4_quota_on_sysfile,
1097 	.quota_off	= ext4_quota_off_sysfile,
1098 	.quota_sync	= dquot_quota_sync,
1099 	.get_info	= dquot_get_dqinfo,
1100 	.set_info	= dquot_set_dqinfo,
1101 	.get_dqblk	= dquot_get_dqblk,
1102 	.set_dqblk	= dquot_set_dqblk
1103 };
1104 #endif
1105 
1106 static const struct super_operations ext4_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 	.put_super	= ext4_put_super,
1114 	.sync_fs	= ext4_sync_fs,
1115 	.freeze_fs	= ext4_freeze,
1116 	.unfreeze_fs	= ext4_unfreeze,
1117 	.statfs		= ext4_statfs,
1118 	.remount_fs	= ext4_remount,
1119 	.show_options	= ext4_show_options,
1120 #ifdef CONFIG_QUOTA
1121 	.quota_read	= ext4_quota_read,
1122 	.quota_write	= ext4_quota_write,
1123 #endif
1124 	.bdev_try_to_free_page = bdev_try_to_free_page,
1125 };
1126 
1127 static const struct super_operations ext4_nojournal_sops = {
1128 	.alloc_inode	= ext4_alloc_inode,
1129 	.destroy_inode	= ext4_destroy_inode,
1130 	.write_inode	= ext4_write_inode,
1131 	.dirty_inode	= ext4_dirty_inode,
1132 	.drop_inode	= ext4_drop_inode,
1133 	.evict_inode	= ext4_evict_inode,
1134 	.sync_fs	= ext4_sync_fs_nojournal,
1135 	.put_super	= ext4_put_super,
1136 	.statfs		= ext4_statfs,
1137 	.remount_fs	= ext4_remount,
1138 	.show_options	= ext4_show_options,
1139 #ifdef CONFIG_QUOTA
1140 	.quota_read	= ext4_quota_read,
1141 	.quota_write	= ext4_quota_write,
1142 #endif
1143 	.bdev_try_to_free_page = bdev_try_to_free_page,
1144 };
1145 
1146 static const struct export_operations ext4_export_ops = {
1147 	.fh_to_dentry = ext4_fh_to_dentry,
1148 	.fh_to_parent = ext4_fh_to_parent,
1149 	.get_parent = ext4_get_parent,
1150 };
1151 
1152 enum {
1153 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1154 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1155 	Opt_nouid32, Opt_debug, Opt_removed,
1156 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1157 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1158 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1159 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1160 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1161 	Opt_data_err_abort, Opt_data_err_ignore,
1162 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1163 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1164 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1165 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1166 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1167 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1168 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1169 	Opt_dioread_nolock, Opt_dioread_lock,
1170 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1171 	Opt_max_dir_size_kb,
1172 };
1173 
1174 static const match_table_t tokens = {
1175 	{Opt_bsd_df, "bsddf"},
1176 	{Opt_minix_df, "minixdf"},
1177 	{Opt_grpid, "grpid"},
1178 	{Opt_grpid, "bsdgroups"},
1179 	{Opt_nogrpid, "nogrpid"},
1180 	{Opt_nogrpid, "sysvgroups"},
1181 	{Opt_resgid, "resgid=%u"},
1182 	{Opt_resuid, "resuid=%u"},
1183 	{Opt_sb, "sb=%u"},
1184 	{Opt_err_cont, "errors=continue"},
1185 	{Opt_err_panic, "errors=panic"},
1186 	{Opt_err_ro, "errors=remount-ro"},
1187 	{Opt_nouid32, "nouid32"},
1188 	{Opt_debug, "debug"},
1189 	{Opt_removed, "oldalloc"},
1190 	{Opt_removed, "orlov"},
1191 	{Opt_user_xattr, "user_xattr"},
1192 	{Opt_nouser_xattr, "nouser_xattr"},
1193 	{Opt_acl, "acl"},
1194 	{Opt_noacl, "noacl"},
1195 	{Opt_noload, "norecovery"},
1196 	{Opt_noload, "noload"},
1197 	{Opt_removed, "nobh"},
1198 	{Opt_removed, "bh"},
1199 	{Opt_commit, "commit=%u"},
1200 	{Opt_min_batch_time, "min_batch_time=%u"},
1201 	{Opt_max_batch_time, "max_batch_time=%u"},
1202 	{Opt_journal_dev, "journal_dev=%u"},
1203 	{Opt_journal_path, "journal_path=%s"},
1204 	{Opt_journal_checksum, "journal_checksum"},
1205 	{Opt_journal_async_commit, "journal_async_commit"},
1206 	{Opt_abort, "abort"},
1207 	{Opt_data_journal, "data=journal"},
1208 	{Opt_data_ordered, "data=ordered"},
1209 	{Opt_data_writeback, "data=writeback"},
1210 	{Opt_data_err_abort, "data_err=abort"},
1211 	{Opt_data_err_ignore, "data_err=ignore"},
1212 	{Opt_offusrjquota, "usrjquota="},
1213 	{Opt_usrjquota, "usrjquota=%s"},
1214 	{Opt_offgrpjquota, "grpjquota="},
1215 	{Opt_grpjquota, "grpjquota=%s"},
1216 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1217 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1218 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1219 	{Opt_grpquota, "grpquota"},
1220 	{Opt_noquota, "noquota"},
1221 	{Opt_quota, "quota"},
1222 	{Opt_usrquota, "usrquota"},
1223 	{Opt_barrier, "barrier=%u"},
1224 	{Opt_barrier, "barrier"},
1225 	{Opt_nobarrier, "nobarrier"},
1226 	{Opt_i_version, "i_version"},
1227 	{Opt_stripe, "stripe=%u"},
1228 	{Opt_delalloc, "delalloc"},
1229 	{Opt_nodelalloc, "nodelalloc"},
1230 	{Opt_removed, "mblk_io_submit"},
1231 	{Opt_removed, "nomblk_io_submit"},
1232 	{Opt_block_validity, "block_validity"},
1233 	{Opt_noblock_validity, "noblock_validity"},
1234 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1235 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1236 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1237 	{Opt_auto_da_alloc, "auto_da_alloc"},
1238 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1239 	{Opt_dioread_nolock, "dioread_nolock"},
1240 	{Opt_dioread_lock, "dioread_lock"},
1241 	{Opt_discard, "discard"},
1242 	{Opt_nodiscard, "nodiscard"},
1243 	{Opt_init_itable, "init_itable=%u"},
1244 	{Opt_init_itable, "init_itable"},
1245 	{Opt_noinit_itable, "noinit_itable"},
1246 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1247 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1248 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1249 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1250 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1251 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1252 	{Opt_err, NULL},
1253 };
1254 
1255 static ext4_fsblk_t get_sb_block(void **data)
1256 {
1257 	ext4_fsblk_t	sb_block;
1258 	char		*options = (char *) *data;
1259 
1260 	if (!options || strncmp(options, "sb=", 3) != 0)
1261 		return 1;	/* Default location */
1262 
1263 	options += 3;
1264 	/* TODO: use simple_strtoll with >32bit ext4 */
1265 	sb_block = simple_strtoul(options, &options, 0);
1266 	if (*options && *options != ',') {
1267 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1268 		       (char *) *data);
1269 		return 1;
1270 	}
1271 	if (*options == ',')
1272 		options++;
1273 	*data = (void *) options;
1274 
1275 	return sb_block;
1276 }
1277 
1278 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1279 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1280 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1281 
1282 #ifdef CONFIG_QUOTA
1283 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1284 {
1285 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1286 	char *qname;
1287 	int ret = -1;
1288 
1289 	if (sb_any_quota_loaded(sb) &&
1290 		!sbi->s_qf_names[qtype]) {
1291 		ext4_msg(sb, KERN_ERR,
1292 			"Cannot change journaled "
1293 			"quota options when quota turned on");
1294 		return -1;
1295 	}
1296 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1297 		ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1298 			 "when QUOTA feature is enabled");
1299 		return -1;
1300 	}
1301 	qname = match_strdup(args);
1302 	if (!qname) {
1303 		ext4_msg(sb, KERN_ERR,
1304 			"Not enough memory for storing quotafile name");
1305 		return -1;
1306 	}
1307 	if (sbi->s_qf_names[qtype]) {
1308 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1309 			ret = 1;
1310 		else
1311 			ext4_msg(sb, KERN_ERR,
1312 				 "%s quota file already specified",
1313 				 QTYPE2NAME(qtype));
1314 		goto errout;
1315 	}
1316 	if (strchr(qname, '/')) {
1317 		ext4_msg(sb, KERN_ERR,
1318 			"quotafile must be on filesystem root");
1319 		goto errout;
1320 	}
1321 	sbi->s_qf_names[qtype] = qname;
1322 	set_opt(sb, QUOTA);
1323 	return 1;
1324 errout:
1325 	kfree(qname);
1326 	return ret;
1327 }
1328 
1329 static int clear_qf_name(struct super_block *sb, int qtype)
1330 {
1331 
1332 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1333 
1334 	if (sb_any_quota_loaded(sb) &&
1335 		sbi->s_qf_names[qtype]) {
1336 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1337 			" when quota turned on");
1338 		return -1;
1339 	}
1340 	kfree(sbi->s_qf_names[qtype]);
1341 	sbi->s_qf_names[qtype] = NULL;
1342 	return 1;
1343 }
1344 #endif
1345 
1346 #define MOPT_SET	0x0001
1347 #define MOPT_CLEAR	0x0002
1348 #define MOPT_NOSUPPORT	0x0004
1349 #define MOPT_EXPLICIT	0x0008
1350 #define MOPT_CLEAR_ERR	0x0010
1351 #define MOPT_GTE0	0x0020
1352 #ifdef CONFIG_QUOTA
1353 #define MOPT_Q		0
1354 #define MOPT_QFMT	0x0040
1355 #else
1356 #define MOPT_Q		MOPT_NOSUPPORT
1357 #define MOPT_QFMT	MOPT_NOSUPPORT
1358 #endif
1359 #define MOPT_DATAJ	0x0080
1360 #define MOPT_NO_EXT2	0x0100
1361 #define MOPT_NO_EXT3	0x0200
1362 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1363 #define MOPT_STRING	0x0400
1364 
1365 static const struct mount_opts {
1366 	int	token;
1367 	int	mount_opt;
1368 	int	flags;
1369 } ext4_mount_opts[] = {
1370 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1371 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1372 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1373 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1374 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1375 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1376 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1377 	 MOPT_EXT4_ONLY | MOPT_SET},
1378 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1379 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1380 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1381 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1382 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1383 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1384 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1385 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1386 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1387 	 MOPT_EXT4_ONLY | MOPT_SET},
1388 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1389 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1390 	 MOPT_EXT4_ONLY | MOPT_SET},
1391 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1392 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1393 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1394 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1395 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1396 	 MOPT_NO_EXT2 | MOPT_SET},
1397 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1398 	 MOPT_NO_EXT2 | MOPT_CLEAR},
1399 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1400 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1401 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1402 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1403 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1404 	{Opt_commit, 0, MOPT_GTE0},
1405 	{Opt_max_batch_time, 0, MOPT_GTE0},
1406 	{Opt_min_batch_time, 0, MOPT_GTE0},
1407 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1408 	{Opt_init_itable, 0, MOPT_GTE0},
1409 	{Opt_stripe, 0, MOPT_GTE0},
1410 	{Opt_resuid, 0, MOPT_GTE0},
1411 	{Opt_resgid, 0, MOPT_GTE0},
1412 	{Opt_journal_dev, 0, MOPT_GTE0},
1413 	{Opt_journal_path, 0, MOPT_STRING},
1414 	{Opt_journal_ioprio, 0, MOPT_GTE0},
1415 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1416 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1417 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1418 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1419 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1420 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1421 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1422 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1423 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1424 #else
1425 	{Opt_acl, 0, MOPT_NOSUPPORT},
1426 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1427 #endif
1428 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1429 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1430 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1431 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1432 							MOPT_SET | MOPT_Q},
1433 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1434 							MOPT_SET | MOPT_Q},
1435 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1436 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1437 	{Opt_usrjquota, 0, MOPT_Q},
1438 	{Opt_grpjquota, 0, MOPT_Q},
1439 	{Opt_offusrjquota, 0, MOPT_Q},
1440 	{Opt_offgrpjquota, 0, MOPT_Q},
1441 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1442 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1443 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1444 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1445 	{Opt_err, 0, 0}
1446 };
1447 
1448 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1449 			    substring_t *args, unsigned long *journal_devnum,
1450 			    unsigned int *journal_ioprio, int is_remount)
1451 {
1452 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1453 	const struct mount_opts *m;
1454 	kuid_t uid;
1455 	kgid_t gid;
1456 	int arg = 0;
1457 
1458 #ifdef CONFIG_QUOTA
1459 	if (token == Opt_usrjquota)
1460 		return set_qf_name(sb, USRQUOTA, &args[0]);
1461 	else if (token == Opt_grpjquota)
1462 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1463 	else if (token == Opt_offusrjquota)
1464 		return clear_qf_name(sb, USRQUOTA);
1465 	else if (token == Opt_offgrpjquota)
1466 		return clear_qf_name(sb, GRPQUOTA);
1467 #endif
1468 	switch (token) {
1469 	case Opt_noacl:
1470 	case Opt_nouser_xattr:
1471 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1472 		break;
1473 	case Opt_sb:
1474 		return 1;	/* handled by get_sb_block() */
1475 	case Opt_removed:
1476 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1477 		return 1;
1478 	case Opt_abort:
1479 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1480 		return 1;
1481 	case Opt_i_version:
1482 		sb->s_flags |= MS_I_VERSION;
1483 		return 1;
1484 	}
1485 
1486 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1487 		if (token == m->token)
1488 			break;
1489 
1490 	if (m->token == Opt_err) {
1491 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1492 			 "or missing value", opt);
1493 		return -1;
1494 	}
1495 
1496 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1497 		ext4_msg(sb, KERN_ERR,
1498 			 "Mount option \"%s\" incompatible with ext2", opt);
1499 		return -1;
1500 	}
1501 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1502 		ext4_msg(sb, KERN_ERR,
1503 			 "Mount option \"%s\" incompatible with ext3", opt);
1504 		return -1;
1505 	}
1506 
1507 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1508 		return -1;
1509 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1510 		return -1;
1511 	if (m->flags & MOPT_EXPLICIT)
1512 		set_opt2(sb, EXPLICIT_DELALLOC);
1513 	if (m->flags & MOPT_CLEAR_ERR)
1514 		clear_opt(sb, ERRORS_MASK);
1515 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1516 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1517 			 "options when quota turned on");
1518 		return -1;
1519 	}
1520 
1521 	if (m->flags & MOPT_NOSUPPORT) {
1522 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1523 	} else if (token == Opt_commit) {
1524 		if (arg == 0)
1525 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1526 		sbi->s_commit_interval = HZ * arg;
1527 	} else if (token == Opt_max_batch_time) {
1528 		sbi->s_max_batch_time = arg;
1529 	} else if (token == Opt_min_batch_time) {
1530 		sbi->s_min_batch_time = arg;
1531 	} else if (token == Opt_inode_readahead_blks) {
1532 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1533 			ext4_msg(sb, KERN_ERR,
1534 				 "EXT4-fs: inode_readahead_blks must be "
1535 				 "0 or a power of 2 smaller than 2^31");
1536 			return -1;
1537 		}
1538 		sbi->s_inode_readahead_blks = arg;
1539 	} else if (token == Opt_init_itable) {
1540 		set_opt(sb, INIT_INODE_TABLE);
1541 		if (!args->from)
1542 			arg = EXT4_DEF_LI_WAIT_MULT;
1543 		sbi->s_li_wait_mult = arg;
1544 	} else if (token == Opt_max_dir_size_kb) {
1545 		sbi->s_max_dir_size_kb = arg;
1546 	} else if (token == Opt_stripe) {
1547 		sbi->s_stripe = arg;
1548 	} else if (token == Opt_resuid) {
1549 		uid = make_kuid(current_user_ns(), arg);
1550 		if (!uid_valid(uid)) {
1551 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1552 			return -1;
1553 		}
1554 		sbi->s_resuid = uid;
1555 	} else if (token == Opt_resgid) {
1556 		gid = make_kgid(current_user_ns(), arg);
1557 		if (!gid_valid(gid)) {
1558 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1559 			return -1;
1560 		}
1561 		sbi->s_resgid = gid;
1562 	} else if (token == Opt_journal_dev) {
1563 		if (is_remount) {
1564 			ext4_msg(sb, KERN_ERR,
1565 				 "Cannot specify journal on remount");
1566 			return -1;
1567 		}
1568 		*journal_devnum = arg;
1569 	} else if (token == Opt_journal_path) {
1570 		char *journal_path;
1571 		struct inode *journal_inode;
1572 		struct path path;
1573 		int error;
1574 
1575 		if (is_remount) {
1576 			ext4_msg(sb, KERN_ERR,
1577 				 "Cannot specify journal on remount");
1578 			return -1;
1579 		}
1580 		journal_path = match_strdup(&args[0]);
1581 		if (!journal_path) {
1582 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1583 				"journal device string");
1584 			return -1;
1585 		}
1586 
1587 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1588 		if (error) {
1589 			ext4_msg(sb, KERN_ERR, "error: could not find "
1590 				"journal device path: error %d", error);
1591 			kfree(journal_path);
1592 			return -1;
1593 		}
1594 
1595 		journal_inode = path.dentry->d_inode;
1596 		if (!S_ISBLK(journal_inode->i_mode)) {
1597 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1598 				"is not a block device", journal_path);
1599 			path_put(&path);
1600 			kfree(journal_path);
1601 			return -1;
1602 		}
1603 
1604 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1605 		path_put(&path);
1606 		kfree(journal_path);
1607 	} else if (token == Opt_journal_ioprio) {
1608 		if (arg > 7) {
1609 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1610 				 " (must be 0-7)");
1611 			return -1;
1612 		}
1613 		*journal_ioprio =
1614 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1615 	} else if (m->flags & MOPT_DATAJ) {
1616 		if (is_remount) {
1617 			if (!sbi->s_journal)
1618 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1619 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1620 				ext4_msg(sb, KERN_ERR,
1621 					 "Cannot change data mode on remount");
1622 				return -1;
1623 			}
1624 		} else {
1625 			clear_opt(sb, DATA_FLAGS);
1626 			sbi->s_mount_opt |= m->mount_opt;
1627 		}
1628 #ifdef CONFIG_QUOTA
1629 	} else if (m->flags & MOPT_QFMT) {
1630 		if (sb_any_quota_loaded(sb) &&
1631 		    sbi->s_jquota_fmt != m->mount_opt) {
1632 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1633 				 "quota options when quota turned on");
1634 			return -1;
1635 		}
1636 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1637 					       EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1638 			ext4_msg(sb, KERN_ERR,
1639 				 "Cannot set journaled quota options "
1640 				 "when QUOTA feature is enabled");
1641 			return -1;
1642 		}
1643 		sbi->s_jquota_fmt = m->mount_opt;
1644 #endif
1645 	} else {
1646 		if (!args->from)
1647 			arg = 1;
1648 		if (m->flags & MOPT_CLEAR)
1649 			arg = !arg;
1650 		else if (unlikely(!(m->flags & MOPT_SET))) {
1651 			ext4_msg(sb, KERN_WARNING,
1652 				 "buggy handling of option %s", opt);
1653 			WARN_ON(1);
1654 			return -1;
1655 		}
1656 		if (arg != 0)
1657 			sbi->s_mount_opt |= m->mount_opt;
1658 		else
1659 			sbi->s_mount_opt &= ~m->mount_opt;
1660 	}
1661 	return 1;
1662 }
1663 
1664 static int parse_options(char *options, struct super_block *sb,
1665 			 unsigned long *journal_devnum,
1666 			 unsigned int *journal_ioprio,
1667 			 int is_remount)
1668 {
1669 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1670 	char *p;
1671 	substring_t args[MAX_OPT_ARGS];
1672 	int token;
1673 
1674 	if (!options)
1675 		return 1;
1676 
1677 	while ((p = strsep(&options, ",")) != NULL) {
1678 		if (!*p)
1679 			continue;
1680 		/*
1681 		 * Initialize args struct so we know whether arg was
1682 		 * found; some options take optional arguments.
1683 		 */
1684 		args[0].to = args[0].from = NULL;
1685 		token = match_token(p, tokens, args);
1686 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1687 				     journal_ioprio, is_remount) < 0)
1688 			return 0;
1689 	}
1690 #ifdef CONFIG_QUOTA
1691 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1692 	    (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1693 		ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1694 			 "feature is enabled");
1695 		return 0;
1696 	}
1697 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1698 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1699 			clear_opt(sb, USRQUOTA);
1700 
1701 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1702 			clear_opt(sb, GRPQUOTA);
1703 
1704 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1705 			ext4_msg(sb, KERN_ERR, "old and new quota "
1706 					"format mixing");
1707 			return 0;
1708 		}
1709 
1710 		if (!sbi->s_jquota_fmt) {
1711 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1712 					"not specified");
1713 			return 0;
1714 		}
1715 	} else {
1716 		if (sbi->s_jquota_fmt) {
1717 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1718 					"specified with no journaling "
1719 					"enabled");
1720 			return 0;
1721 		}
1722 	}
1723 #endif
1724 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1725 		int blocksize =
1726 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1727 
1728 		if (blocksize < PAGE_CACHE_SIZE) {
1729 			ext4_msg(sb, KERN_ERR, "can't mount with "
1730 				 "dioread_nolock if block size != PAGE_SIZE");
1731 			return 0;
1732 		}
1733 	}
1734 	return 1;
1735 }
1736 
1737 static inline void ext4_show_quota_options(struct seq_file *seq,
1738 					   struct super_block *sb)
1739 {
1740 #if defined(CONFIG_QUOTA)
1741 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1742 
1743 	if (sbi->s_jquota_fmt) {
1744 		char *fmtname = "";
1745 
1746 		switch (sbi->s_jquota_fmt) {
1747 		case QFMT_VFS_OLD:
1748 			fmtname = "vfsold";
1749 			break;
1750 		case QFMT_VFS_V0:
1751 			fmtname = "vfsv0";
1752 			break;
1753 		case QFMT_VFS_V1:
1754 			fmtname = "vfsv1";
1755 			break;
1756 		}
1757 		seq_printf(seq, ",jqfmt=%s", fmtname);
1758 	}
1759 
1760 	if (sbi->s_qf_names[USRQUOTA])
1761 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1762 
1763 	if (sbi->s_qf_names[GRPQUOTA])
1764 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1765 #endif
1766 }
1767 
1768 static const char *token2str(int token)
1769 {
1770 	const struct match_token *t;
1771 
1772 	for (t = tokens; t->token != Opt_err; t++)
1773 		if (t->token == token && !strchr(t->pattern, '='))
1774 			break;
1775 	return t->pattern;
1776 }
1777 
1778 /*
1779  * Show an option if
1780  *  - it's set to a non-default value OR
1781  *  - if the per-sb default is different from the global default
1782  */
1783 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1784 			      int nodefs)
1785 {
1786 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1787 	struct ext4_super_block *es = sbi->s_es;
1788 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1789 	const struct mount_opts *m;
1790 	char sep = nodefs ? '\n' : ',';
1791 
1792 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1793 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1794 
1795 	if (sbi->s_sb_block != 1)
1796 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1797 
1798 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1799 		int want_set = m->flags & MOPT_SET;
1800 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1801 		    (m->flags & MOPT_CLEAR_ERR))
1802 			continue;
1803 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1804 			continue; /* skip if same as the default */
1805 		if ((want_set &&
1806 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1807 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1808 			continue; /* select Opt_noFoo vs Opt_Foo */
1809 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1810 	}
1811 
1812 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1813 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1814 		SEQ_OPTS_PRINT("resuid=%u",
1815 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1816 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1817 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1818 		SEQ_OPTS_PRINT("resgid=%u",
1819 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1820 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1821 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1822 		SEQ_OPTS_PUTS("errors=remount-ro");
1823 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1824 		SEQ_OPTS_PUTS("errors=continue");
1825 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1826 		SEQ_OPTS_PUTS("errors=panic");
1827 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1828 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1829 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1830 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1831 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1832 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1833 	if (sb->s_flags & MS_I_VERSION)
1834 		SEQ_OPTS_PUTS("i_version");
1835 	if (nodefs || sbi->s_stripe)
1836 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1837 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1838 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1839 			SEQ_OPTS_PUTS("data=journal");
1840 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1841 			SEQ_OPTS_PUTS("data=ordered");
1842 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1843 			SEQ_OPTS_PUTS("data=writeback");
1844 	}
1845 	if (nodefs ||
1846 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1847 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1848 			       sbi->s_inode_readahead_blks);
1849 
1850 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1851 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1852 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1853 	if (nodefs || sbi->s_max_dir_size_kb)
1854 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1855 
1856 	ext4_show_quota_options(seq, sb);
1857 	return 0;
1858 }
1859 
1860 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1861 {
1862 	return _ext4_show_options(seq, root->d_sb, 0);
1863 }
1864 
1865 static int options_seq_show(struct seq_file *seq, void *offset)
1866 {
1867 	struct super_block *sb = seq->private;
1868 	int rc;
1869 
1870 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1871 	rc = _ext4_show_options(seq, sb, 1);
1872 	seq_puts(seq, "\n");
1873 	return rc;
1874 }
1875 
1876 static int options_open_fs(struct inode *inode, struct file *file)
1877 {
1878 	return single_open(file, options_seq_show, PDE_DATA(inode));
1879 }
1880 
1881 static const struct file_operations ext4_seq_options_fops = {
1882 	.owner = THIS_MODULE,
1883 	.open = options_open_fs,
1884 	.read = seq_read,
1885 	.llseek = seq_lseek,
1886 	.release = single_release,
1887 };
1888 
1889 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1890 			    int read_only)
1891 {
1892 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1893 	int res = 0;
1894 
1895 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1896 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1897 			 "forcing read-only mode");
1898 		res = MS_RDONLY;
1899 	}
1900 	if (read_only)
1901 		goto done;
1902 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1903 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1904 			 "running e2fsck is recommended");
1905 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
1906 		ext4_msg(sb, KERN_WARNING,
1907 			 "warning: mounting fs with errors, "
1908 			 "running e2fsck is recommended");
1909 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1910 		 le16_to_cpu(es->s_mnt_count) >=
1911 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1912 		ext4_msg(sb, KERN_WARNING,
1913 			 "warning: maximal mount count reached, "
1914 			 "running e2fsck is recommended");
1915 	else if (le32_to_cpu(es->s_checkinterval) &&
1916 		(le32_to_cpu(es->s_lastcheck) +
1917 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1918 		ext4_msg(sb, KERN_WARNING,
1919 			 "warning: checktime reached, "
1920 			 "running e2fsck is recommended");
1921 	if (!sbi->s_journal)
1922 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1923 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1924 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1925 	le16_add_cpu(&es->s_mnt_count, 1);
1926 	es->s_mtime = cpu_to_le32(get_seconds());
1927 	ext4_update_dynamic_rev(sb);
1928 	if (sbi->s_journal)
1929 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1930 
1931 	ext4_commit_super(sb, 1);
1932 done:
1933 	if (test_opt(sb, DEBUG))
1934 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1935 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1936 			sb->s_blocksize,
1937 			sbi->s_groups_count,
1938 			EXT4_BLOCKS_PER_GROUP(sb),
1939 			EXT4_INODES_PER_GROUP(sb),
1940 			sbi->s_mount_opt, sbi->s_mount_opt2);
1941 
1942 	cleancache_init_fs(sb);
1943 	return res;
1944 }
1945 
1946 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1947 {
1948 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1949 	struct flex_groups *new_groups;
1950 	int size;
1951 
1952 	if (!sbi->s_log_groups_per_flex)
1953 		return 0;
1954 
1955 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
1956 	if (size <= sbi->s_flex_groups_allocated)
1957 		return 0;
1958 
1959 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1960 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1961 	if (!new_groups) {
1962 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1963 			 size / (int) sizeof(struct flex_groups));
1964 		return -ENOMEM;
1965 	}
1966 
1967 	if (sbi->s_flex_groups) {
1968 		memcpy(new_groups, sbi->s_flex_groups,
1969 		       (sbi->s_flex_groups_allocated *
1970 			sizeof(struct flex_groups)));
1971 		ext4_kvfree(sbi->s_flex_groups);
1972 	}
1973 	sbi->s_flex_groups = new_groups;
1974 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1975 	return 0;
1976 }
1977 
1978 static int ext4_fill_flex_info(struct super_block *sb)
1979 {
1980 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1981 	struct ext4_group_desc *gdp = NULL;
1982 	ext4_group_t flex_group;
1983 	int i, err;
1984 
1985 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1986 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1987 		sbi->s_log_groups_per_flex = 0;
1988 		return 1;
1989 	}
1990 
1991 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1992 	if (err)
1993 		goto failed;
1994 
1995 	for (i = 0; i < sbi->s_groups_count; i++) {
1996 		gdp = ext4_get_group_desc(sb, i, NULL);
1997 
1998 		flex_group = ext4_flex_group(sbi, i);
1999 		atomic_add(ext4_free_inodes_count(sb, gdp),
2000 			   &sbi->s_flex_groups[flex_group].free_inodes);
2001 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2002 			     &sbi->s_flex_groups[flex_group].free_clusters);
2003 		atomic_add(ext4_used_dirs_count(sb, gdp),
2004 			   &sbi->s_flex_groups[flex_group].used_dirs);
2005 	}
2006 
2007 	return 1;
2008 failed:
2009 	return 0;
2010 }
2011 
2012 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2013 				   struct ext4_group_desc *gdp)
2014 {
2015 	int offset;
2016 	__u16 crc = 0;
2017 	__le32 le_group = cpu_to_le32(block_group);
2018 
2019 	if ((sbi->s_es->s_feature_ro_compat &
2020 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
2021 		/* Use new metadata_csum algorithm */
2022 		__le16 save_csum;
2023 		__u32 csum32;
2024 
2025 		save_csum = gdp->bg_checksum;
2026 		gdp->bg_checksum = 0;
2027 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2028 				     sizeof(le_group));
2029 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2030 				     sbi->s_desc_size);
2031 		gdp->bg_checksum = save_csum;
2032 
2033 		crc = csum32 & 0xFFFF;
2034 		goto out;
2035 	}
2036 
2037 	/* old crc16 code */
2038 	offset = offsetof(struct ext4_group_desc, bg_checksum);
2039 
2040 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2041 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2042 	crc = crc16(crc, (__u8 *)gdp, offset);
2043 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2044 	/* for checksum of struct ext4_group_desc do the rest...*/
2045 	if ((sbi->s_es->s_feature_incompat &
2046 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2047 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2048 		crc = crc16(crc, (__u8 *)gdp + offset,
2049 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2050 				offset);
2051 
2052 out:
2053 	return cpu_to_le16(crc);
2054 }
2055 
2056 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2057 				struct ext4_group_desc *gdp)
2058 {
2059 	if (ext4_has_group_desc_csum(sb) &&
2060 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2061 						      block_group, gdp)))
2062 		return 0;
2063 
2064 	return 1;
2065 }
2066 
2067 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2068 			      struct ext4_group_desc *gdp)
2069 {
2070 	if (!ext4_has_group_desc_csum(sb))
2071 		return;
2072 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2073 }
2074 
2075 /* Called at mount-time, super-block is locked */
2076 static int ext4_check_descriptors(struct super_block *sb,
2077 				  ext4_group_t *first_not_zeroed)
2078 {
2079 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2080 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2081 	ext4_fsblk_t last_block;
2082 	ext4_fsblk_t block_bitmap;
2083 	ext4_fsblk_t inode_bitmap;
2084 	ext4_fsblk_t inode_table;
2085 	int flexbg_flag = 0;
2086 	ext4_group_t i, grp = sbi->s_groups_count;
2087 
2088 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2089 		flexbg_flag = 1;
2090 
2091 	ext4_debug("Checking group descriptors");
2092 
2093 	for (i = 0; i < sbi->s_groups_count; i++) {
2094 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2095 
2096 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2097 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2098 		else
2099 			last_block = first_block +
2100 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2101 
2102 		if ((grp == sbi->s_groups_count) &&
2103 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2104 			grp = i;
2105 
2106 		block_bitmap = ext4_block_bitmap(sb, gdp);
2107 		if (block_bitmap < first_block || block_bitmap > last_block) {
2108 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2109 			       "Block bitmap for group %u not in group "
2110 			       "(block %llu)!", i, block_bitmap);
2111 			return 0;
2112 		}
2113 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2114 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2115 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2116 			       "Inode bitmap for group %u not in group "
2117 			       "(block %llu)!", i, inode_bitmap);
2118 			return 0;
2119 		}
2120 		inode_table = ext4_inode_table(sb, gdp);
2121 		if (inode_table < first_block ||
2122 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2123 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2124 			       "Inode table for group %u not in group "
2125 			       "(block %llu)!", i, inode_table);
2126 			return 0;
2127 		}
2128 		ext4_lock_group(sb, i);
2129 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2130 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2131 				 "Checksum for group %u failed (%u!=%u)",
2132 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2133 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2134 			if (!(sb->s_flags & MS_RDONLY)) {
2135 				ext4_unlock_group(sb, i);
2136 				return 0;
2137 			}
2138 		}
2139 		ext4_unlock_group(sb, i);
2140 		if (!flexbg_flag)
2141 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2142 	}
2143 	if (NULL != first_not_zeroed)
2144 		*first_not_zeroed = grp;
2145 	return 1;
2146 }
2147 
2148 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2149  * the superblock) which were deleted from all directories, but held open by
2150  * a process at the time of a crash.  We walk the list and try to delete these
2151  * inodes at recovery time (only with a read-write filesystem).
2152  *
2153  * In order to keep the orphan inode chain consistent during traversal (in
2154  * case of crash during recovery), we link each inode into the superblock
2155  * orphan list_head and handle it the same way as an inode deletion during
2156  * normal operation (which journals the operations for us).
2157  *
2158  * We only do an iget() and an iput() on each inode, which is very safe if we
2159  * accidentally point at an in-use or already deleted inode.  The worst that
2160  * can happen in this case is that we get a "bit already cleared" message from
2161  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2162  * e2fsck was run on this filesystem, and it must have already done the orphan
2163  * inode cleanup for us, so we can safely abort without any further action.
2164  */
2165 static void ext4_orphan_cleanup(struct super_block *sb,
2166 				struct ext4_super_block *es)
2167 {
2168 	unsigned int s_flags = sb->s_flags;
2169 	int nr_orphans = 0, nr_truncates = 0;
2170 #ifdef CONFIG_QUOTA
2171 	int i;
2172 #endif
2173 	if (!es->s_last_orphan) {
2174 		jbd_debug(4, "no orphan inodes to clean up\n");
2175 		return;
2176 	}
2177 
2178 	if (bdev_read_only(sb->s_bdev)) {
2179 		ext4_msg(sb, KERN_ERR, "write access "
2180 			"unavailable, skipping orphan cleanup");
2181 		return;
2182 	}
2183 
2184 	/* Check if feature set would not allow a r/w mount */
2185 	if (!ext4_feature_set_ok(sb, 0)) {
2186 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2187 			 "unknown ROCOMPAT features");
2188 		return;
2189 	}
2190 
2191 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2192 		/* don't clear list on RO mount w/ errors */
2193 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2194 			jbd_debug(1, "Errors on filesystem, "
2195 				  "clearing orphan list.\n");
2196 			es->s_last_orphan = 0;
2197 		}
2198 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2199 		return;
2200 	}
2201 
2202 	if (s_flags & MS_RDONLY) {
2203 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2204 		sb->s_flags &= ~MS_RDONLY;
2205 	}
2206 #ifdef CONFIG_QUOTA
2207 	/* Needed for iput() to work correctly and not trash data */
2208 	sb->s_flags |= MS_ACTIVE;
2209 	/* Turn on quotas so that they are updated correctly */
2210 	for (i = 0; i < MAXQUOTAS; i++) {
2211 		if (EXT4_SB(sb)->s_qf_names[i]) {
2212 			int ret = ext4_quota_on_mount(sb, i);
2213 			if (ret < 0)
2214 				ext4_msg(sb, KERN_ERR,
2215 					"Cannot turn on journaled "
2216 					"quota: error %d", ret);
2217 		}
2218 	}
2219 #endif
2220 
2221 	while (es->s_last_orphan) {
2222 		struct inode *inode;
2223 
2224 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2225 		if (IS_ERR(inode)) {
2226 			es->s_last_orphan = 0;
2227 			break;
2228 		}
2229 
2230 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2231 		dquot_initialize(inode);
2232 		if (inode->i_nlink) {
2233 			if (test_opt(sb, DEBUG))
2234 				ext4_msg(sb, KERN_DEBUG,
2235 					"%s: truncating inode %lu to %lld bytes",
2236 					__func__, inode->i_ino, inode->i_size);
2237 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2238 				  inode->i_ino, inode->i_size);
2239 			mutex_lock(&inode->i_mutex);
2240 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2241 			ext4_truncate(inode);
2242 			mutex_unlock(&inode->i_mutex);
2243 			nr_truncates++;
2244 		} else {
2245 			if (test_opt(sb, DEBUG))
2246 				ext4_msg(sb, KERN_DEBUG,
2247 					"%s: deleting unreferenced inode %lu",
2248 					__func__, inode->i_ino);
2249 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2250 				  inode->i_ino);
2251 			nr_orphans++;
2252 		}
2253 		iput(inode);  /* The delete magic happens here! */
2254 	}
2255 
2256 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2257 
2258 	if (nr_orphans)
2259 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2260 		       PLURAL(nr_orphans));
2261 	if (nr_truncates)
2262 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2263 		       PLURAL(nr_truncates));
2264 #ifdef CONFIG_QUOTA
2265 	/* Turn quotas off */
2266 	for (i = 0; i < MAXQUOTAS; i++) {
2267 		if (sb_dqopt(sb)->files[i])
2268 			dquot_quota_off(sb, i);
2269 	}
2270 #endif
2271 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2272 }
2273 
2274 /*
2275  * Maximal extent format file size.
2276  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2277  * extent format containers, within a sector_t, and within i_blocks
2278  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2279  * so that won't be a limiting factor.
2280  *
2281  * However there is other limiting factor. We do store extents in the form
2282  * of starting block and length, hence the resulting length of the extent
2283  * covering maximum file size must fit into on-disk format containers as
2284  * well. Given that length is always by 1 unit bigger than max unit (because
2285  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2286  *
2287  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2288  */
2289 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2290 {
2291 	loff_t res;
2292 	loff_t upper_limit = MAX_LFS_FILESIZE;
2293 
2294 	/* small i_blocks in vfs inode? */
2295 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2296 		/*
2297 		 * CONFIG_LBDAF is not enabled implies the inode
2298 		 * i_block represent total blocks in 512 bytes
2299 		 * 32 == size of vfs inode i_blocks * 8
2300 		 */
2301 		upper_limit = (1LL << 32) - 1;
2302 
2303 		/* total blocks in file system block size */
2304 		upper_limit >>= (blkbits - 9);
2305 		upper_limit <<= blkbits;
2306 	}
2307 
2308 	/*
2309 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2310 	 * by one fs block, so ee_len can cover the extent of maximum file
2311 	 * size
2312 	 */
2313 	res = (1LL << 32) - 1;
2314 	res <<= blkbits;
2315 
2316 	/* Sanity check against vm- & vfs- imposed limits */
2317 	if (res > upper_limit)
2318 		res = upper_limit;
2319 
2320 	return res;
2321 }
2322 
2323 /*
2324  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2325  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2326  * We need to be 1 filesystem block less than the 2^48 sector limit.
2327  */
2328 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2329 {
2330 	loff_t res = EXT4_NDIR_BLOCKS;
2331 	int meta_blocks;
2332 	loff_t upper_limit;
2333 	/* This is calculated to be the largest file size for a dense, block
2334 	 * mapped file such that the file's total number of 512-byte sectors,
2335 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2336 	 *
2337 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2338 	 * number of 512-byte sectors of the file.
2339 	 */
2340 
2341 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2342 		/*
2343 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2344 		 * the inode i_block field represents total file blocks in
2345 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2346 		 */
2347 		upper_limit = (1LL << 32) - 1;
2348 
2349 		/* total blocks in file system block size */
2350 		upper_limit >>= (bits - 9);
2351 
2352 	} else {
2353 		/*
2354 		 * We use 48 bit ext4_inode i_blocks
2355 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2356 		 * represent total number of blocks in
2357 		 * file system block size
2358 		 */
2359 		upper_limit = (1LL << 48) - 1;
2360 
2361 	}
2362 
2363 	/* indirect blocks */
2364 	meta_blocks = 1;
2365 	/* double indirect blocks */
2366 	meta_blocks += 1 + (1LL << (bits-2));
2367 	/* tripple indirect blocks */
2368 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2369 
2370 	upper_limit -= meta_blocks;
2371 	upper_limit <<= bits;
2372 
2373 	res += 1LL << (bits-2);
2374 	res += 1LL << (2*(bits-2));
2375 	res += 1LL << (3*(bits-2));
2376 	res <<= bits;
2377 	if (res > upper_limit)
2378 		res = upper_limit;
2379 
2380 	if (res > MAX_LFS_FILESIZE)
2381 		res = MAX_LFS_FILESIZE;
2382 
2383 	return res;
2384 }
2385 
2386 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2387 				   ext4_fsblk_t logical_sb_block, int nr)
2388 {
2389 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2390 	ext4_group_t bg, first_meta_bg;
2391 	int has_super = 0;
2392 
2393 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2394 
2395 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2396 	    nr < first_meta_bg)
2397 		return logical_sb_block + nr + 1;
2398 	bg = sbi->s_desc_per_block * nr;
2399 	if (ext4_bg_has_super(sb, bg))
2400 		has_super = 1;
2401 
2402 	/*
2403 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2404 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2405 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2406 	 * compensate.
2407 	 */
2408 	if (sb->s_blocksize == 1024 && nr == 0 &&
2409 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2410 		has_super++;
2411 
2412 	return (has_super + ext4_group_first_block_no(sb, bg));
2413 }
2414 
2415 /**
2416  * ext4_get_stripe_size: Get the stripe size.
2417  * @sbi: In memory super block info
2418  *
2419  * If we have specified it via mount option, then
2420  * use the mount option value. If the value specified at mount time is
2421  * greater than the blocks per group use the super block value.
2422  * If the super block value is greater than blocks per group return 0.
2423  * Allocator needs it be less than blocks per group.
2424  *
2425  */
2426 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2427 {
2428 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2429 	unsigned long stripe_width =
2430 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2431 	int ret;
2432 
2433 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2434 		ret = sbi->s_stripe;
2435 	else if (stripe_width <= sbi->s_blocks_per_group)
2436 		ret = stripe_width;
2437 	else if (stride <= sbi->s_blocks_per_group)
2438 		ret = stride;
2439 	else
2440 		ret = 0;
2441 
2442 	/*
2443 	 * If the stripe width is 1, this makes no sense and
2444 	 * we set it to 0 to turn off stripe handling code.
2445 	 */
2446 	if (ret <= 1)
2447 		ret = 0;
2448 
2449 	return ret;
2450 }
2451 
2452 /* sysfs supprt */
2453 
2454 struct ext4_attr {
2455 	struct attribute attr;
2456 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2457 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2458 			 const char *, size_t);
2459 	union {
2460 		int offset;
2461 		int deprecated_val;
2462 	} u;
2463 };
2464 
2465 static int parse_strtoull(const char *buf,
2466 		unsigned long long max, unsigned long long *value)
2467 {
2468 	int ret;
2469 
2470 	ret = kstrtoull(skip_spaces(buf), 0, value);
2471 	if (!ret && *value > max)
2472 		ret = -EINVAL;
2473 	return ret;
2474 }
2475 
2476 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2477 					      struct ext4_sb_info *sbi,
2478 					      char *buf)
2479 {
2480 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2481 		(s64) EXT4_C2B(sbi,
2482 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2483 }
2484 
2485 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2486 					 struct ext4_sb_info *sbi, char *buf)
2487 {
2488 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2489 
2490 	if (!sb->s_bdev->bd_part)
2491 		return snprintf(buf, PAGE_SIZE, "0\n");
2492 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2493 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2494 			 sbi->s_sectors_written_start) >> 1);
2495 }
2496 
2497 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2498 					  struct ext4_sb_info *sbi, char *buf)
2499 {
2500 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2501 
2502 	if (!sb->s_bdev->bd_part)
2503 		return snprintf(buf, PAGE_SIZE, "0\n");
2504 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2505 			(unsigned long long)(sbi->s_kbytes_written +
2506 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2507 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2508 }
2509 
2510 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2511 					  struct ext4_sb_info *sbi,
2512 					  const char *buf, size_t count)
2513 {
2514 	unsigned long t;
2515 	int ret;
2516 
2517 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2518 	if (ret)
2519 		return ret;
2520 
2521 	if (t && (!is_power_of_2(t) || t > 0x40000000))
2522 		return -EINVAL;
2523 
2524 	sbi->s_inode_readahead_blks = t;
2525 	return count;
2526 }
2527 
2528 static ssize_t sbi_ui_show(struct ext4_attr *a,
2529 			   struct ext4_sb_info *sbi, char *buf)
2530 {
2531 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2532 
2533 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2534 }
2535 
2536 static ssize_t sbi_ui_store(struct ext4_attr *a,
2537 			    struct ext4_sb_info *sbi,
2538 			    const char *buf, size_t count)
2539 {
2540 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2541 	unsigned long t;
2542 	int ret;
2543 
2544 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2545 	if (ret)
2546 		return ret;
2547 	*ui = t;
2548 	return count;
2549 }
2550 
2551 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2552 				  struct ext4_sb_info *sbi, char *buf)
2553 {
2554 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2555 		(unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2556 }
2557 
2558 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2559 				   struct ext4_sb_info *sbi,
2560 				   const char *buf, size_t count)
2561 {
2562 	unsigned long long val;
2563 	int ret;
2564 
2565 	if (parse_strtoull(buf, -1ULL, &val))
2566 		return -EINVAL;
2567 	ret = ext4_reserve_clusters(sbi, val);
2568 
2569 	return ret ? ret : count;
2570 }
2571 
2572 static ssize_t trigger_test_error(struct ext4_attr *a,
2573 				  struct ext4_sb_info *sbi,
2574 				  const char *buf, size_t count)
2575 {
2576 	int len = count;
2577 
2578 	if (!capable(CAP_SYS_ADMIN))
2579 		return -EPERM;
2580 
2581 	if (len && buf[len-1] == '\n')
2582 		len--;
2583 
2584 	if (len)
2585 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2586 	return count;
2587 }
2588 
2589 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2590 				   struct ext4_sb_info *sbi, char *buf)
2591 {
2592 	return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2593 }
2594 
2595 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2596 static struct ext4_attr ext4_attr_##_name = {			\
2597 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2598 	.show	= _show,					\
2599 	.store	= _store,					\
2600 	.u = {							\
2601 		.offset = offsetof(struct ext4_sb_info, _elname),\
2602 	},							\
2603 }
2604 #define EXT4_ATTR(name, mode, show, store) \
2605 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2606 
2607 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2608 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2609 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2610 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2611 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2612 #define ATTR_LIST(name) &ext4_attr_##name.attr
2613 #define EXT4_DEPRECATED_ATTR(_name, _val)	\
2614 static struct ext4_attr ext4_attr_##_name = {			\
2615 	.attr = {.name = __stringify(_name), .mode = 0444 },	\
2616 	.show	= sbi_deprecated_show,				\
2617 	.u = {							\
2618 		.deprecated_val = _val,				\
2619 	},							\
2620 }
2621 
2622 EXT4_RO_ATTR(delayed_allocation_blocks);
2623 EXT4_RO_ATTR(session_write_kbytes);
2624 EXT4_RO_ATTR(lifetime_write_kbytes);
2625 EXT4_RW_ATTR(reserved_clusters);
2626 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2627 		 inode_readahead_blks_store, s_inode_readahead_blks);
2628 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2629 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2630 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2631 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2632 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2633 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2634 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2635 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2636 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2637 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2638 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2639 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2640 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2641 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2642 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2643 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2644 
2645 static struct attribute *ext4_attrs[] = {
2646 	ATTR_LIST(delayed_allocation_blocks),
2647 	ATTR_LIST(session_write_kbytes),
2648 	ATTR_LIST(lifetime_write_kbytes),
2649 	ATTR_LIST(reserved_clusters),
2650 	ATTR_LIST(inode_readahead_blks),
2651 	ATTR_LIST(inode_goal),
2652 	ATTR_LIST(mb_stats),
2653 	ATTR_LIST(mb_max_to_scan),
2654 	ATTR_LIST(mb_min_to_scan),
2655 	ATTR_LIST(mb_order2_req),
2656 	ATTR_LIST(mb_stream_req),
2657 	ATTR_LIST(mb_group_prealloc),
2658 	ATTR_LIST(max_writeback_mb_bump),
2659 	ATTR_LIST(extent_max_zeroout_kb),
2660 	ATTR_LIST(trigger_fs_error),
2661 	ATTR_LIST(err_ratelimit_interval_ms),
2662 	ATTR_LIST(err_ratelimit_burst),
2663 	ATTR_LIST(warning_ratelimit_interval_ms),
2664 	ATTR_LIST(warning_ratelimit_burst),
2665 	ATTR_LIST(msg_ratelimit_interval_ms),
2666 	ATTR_LIST(msg_ratelimit_burst),
2667 	NULL,
2668 };
2669 
2670 /* Features this copy of ext4 supports */
2671 EXT4_INFO_ATTR(lazy_itable_init);
2672 EXT4_INFO_ATTR(batched_discard);
2673 EXT4_INFO_ATTR(meta_bg_resize);
2674 
2675 static struct attribute *ext4_feat_attrs[] = {
2676 	ATTR_LIST(lazy_itable_init),
2677 	ATTR_LIST(batched_discard),
2678 	ATTR_LIST(meta_bg_resize),
2679 	NULL,
2680 };
2681 
2682 static ssize_t ext4_attr_show(struct kobject *kobj,
2683 			      struct attribute *attr, char *buf)
2684 {
2685 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2686 						s_kobj);
2687 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2688 
2689 	return a->show ? a->show(a, sbi, buf) : 0;
2690 }
2691 
2692 static ssize_t ext4_attr_store(struct kobject *kobj,
2693 			       struct attribute *attr,
2694 			       const char *buf, size_t len)
2695 {
2696 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2697 						s_kobj);
2698 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2699 
2700 	return a->store ? a->store(a, sbi, buf, len) : 0;
2701 }
2702 
2703 static void ext4_sb_release(struct kobject *kobj)
2704 {
2705 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2706 						s_kobj);
2707 	complete(&sbi->s_kobj_unregister);
2708 }
2709 
2710 static const struct sysfs_ops ext4_attr_ops = {
2711 	.show	= ext4_attr_show,
2712 	.store	= ext4_attr_store,
2713 };
2714 
2715 static struct kobj_type ext4_ktype = {
2716 	.default_attrs	= ext4_attrs,
2717 	.sysfs_ops	= &ext4_attr_ops,
2718 	.release	= ext4_sb_release,
2719 };
2720 
2721 static void ext4_feat_release(struct kobject *kobj)
2722 {
2723 	complete(&ext4_feat->f_kobj_unregister);
2724 }
2725 
2726 static struct kobj_type ext4_feat_ktype = {
2727 	.default_attrs	= ext4_feat_attrs,
2728 	.sysfs_ops	= &ext4_attr_ops,
2729 	.release	= ext4_feat_release,
2730 };
2731 
2732 /*
2733  * Check whether this filesystem can be mounted based on
2734  * the features present and the RDONLY/RDWR mount requested.
2735  * Returns 1 if this filesystem can be mounted as requested,
2736  * 0 if it cannot be.
2737  */
2738 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2739 {
2740 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2741 		ext4_msg(sb, KERN_ERR,
2742 			"Couldn't mount because of "
2743 			"unsupported optional features (%x)",
2744 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2745 			~EXT4_FEATURE_INCOMPAT_SUPP));
2746 		return 0;
2747 	}
2748 
2749 	if (readonly)
2750 		return 1;
2751 
2752 	/* Check that feature set is OK for a read-write mount */
2753 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2754 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2755 			 "unsupported optional features (%x)",
2756 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2757 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2758 		return 0;
2759 	}
2760 	/*
2761 	 * Large file size enabled file system can only be mounted
2762 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2763 	 */
2764 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2765 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2766 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2767 				 "cannot be mounted RDWR without "
2768 				 "CONFIG_LBDAF");
2769 			return 0;
2770 		}
2771 	}
2772 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2773 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2774 		ext4_msg(sb, KERN_ERR,
2775 			 "Can't support bigalloc feature without "
2776 			 "extents feature\n");
2777 		return 0;
2778 	}
2779 
2780 #ifndef CONFIG_QUOTA
2781 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2782 	    !readonly) {
2783 		ext4_msg(sb, KERN_ERR,
2784 			 "Filesystem with quota feature cannot be mounted RDWR "
2785 			 "without CONFIG_QUOTA");
2786 		return 0;
2787 	}
2788 #endif  /* CONFIG_QUOTA */
2789 	return 1;
2790 }
2791 
2792 /*
2793  * This function is called once a day if we have errors logged
2794  * on the file system
2795  */
2796 static void print_daily_error_info(unsigned long arg)
2797 {
2798 	struct super_block *sb = (struct super_block *) arg;
2799 	struct ext4_sb_info *sbi;
2800 	struct ext4_super_block *es;
2801 
2802 	sbi = EXT4_SB(sb);
2803 	es = sbi->s_es;
2804 
2805 	if (es->s_error_count)
2806 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2807 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2808 			 le32_to_cpu(es->s_error_count));
2809 	if (es->s_first_error_time) {
2810 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2811 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2812 		       (int) sizeof(es->s_first_error_func),
2813 		       es->s_first_error_func,
2814 		       le32_to_cpu(es->s_first_error_line));
2815 		if (es->s_first_error_ino)
2816 			printk(": inode %u",
2817 			       le32_to_cpu(es->s_first_error_ino));
2818 		if (es->s_first_error_block)
2819 			printk(": block %llu", (unsigned long long)
2820 			       le64_to_cpu(es->s_first_error_block));
2821 		printk("\n");
2822 	}
2823 	if (es->s_last_error_time) {
2824 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2825 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2826 		       (int) sizeof(es->s_last_error_func),
2827 		       es->s_last_error_func,
2828 		       le32_to_cpu(es->s_last_error_line));
2829 		if (es->s_last_error_ino)
2830 			printk(": inode %u",
2831 			       le32_to_cpu(es->s_last_error_ino));
2832 		if (es->s_last_error_block)
2833 			printk(": block %llu", (unsigned long long)
2834 			       le64_to_cpu(es->s_last_error_block));
2835 		printk("\n");
2836 	}
2837 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2838 }
2839 
2840 /* Find next suitable group and run ext4_init_inode_table */
2841 static int ext4_run_li_request(struct ext4_li_request *elr)
2842 {
2843 	struct ext4_group_desc *gdp = NULL;
2844 	ext4_group_t group, ngroups;
2845 	struct super_block *sb;
2846 	unsigned long timeout = 0;
2847 	int ret = 0;
2848 
2849 	sb = elr->lr_super;
2850 	ngroups = EXT4_SB(sb)->s_groups_count;
2851 
2852 	sb_start_write(sb);
2853 	for (group = elr->lr_next_group; group < ngroups; group++) {
2854 		gdp = ext4_get_group_desc(sb, group, NULL);
2855 		if (!gdp) {
2856 			ret = 1;
2857 			break;
2858 		}
2859 
2860 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2861 			break;
2862 	}
2863 
2864 	if (group >= ngroups)
2865 		ret = 1;
2866 
2867 	if (!ret) {
2868 		timeout = jiffies;
2869 		ret = ext4_init_inode_table(sb, group,
2870 					    elr->lr_timeout ? 0 : 1);
2871 		if (elr->lr_timeout == 0) {
2872 			timeout = (jiffies - timeout) *
2873 				  elr->lr_sbi->s_li_wait_mult;
2874 			elr->lr_timeout = timeout;
2875 		}
2876 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2877 		elr->lr_next_group = group + 1;
2878 	}
2879 	sb_end_write(sb);
2880 
2881 	return ret;
2882 }
2883 
2884 /*
2885  * Remove lr_request from the list_request and free the
2886  * request structure. Should be called with li_list_mtx held
2887  */
2888 static void ext4_remove_li_request(struct ext4_li_request *elr)
2889 {
2890 	struct ext4_sb_info *sbi;
2891 
2892 	if (!elr)
2893 		return;
2894 
2895 	sbi = elr->lr_sbi;
2896 
2897 	list_del(&elr->lr_request);
2898 	sbi->s_li_request = NULL;
2899 	kfree(elr);
2900 }
2901 
2902 static void ext4_unregister_li_request(struct super_block *sb)
2903 {
2904 	mutex_lock(&ext4_li_mtx);
2905 	if (!ext4_li_info) {
2906 		mutex_unlock(&ext4_li_mtx);
2907 		return;
2908 	}
2909 
2910 	mutex_lock(&ext4_li_info->li_list_mtx);
2911 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2912 	mutex_unlock(&ext4_li_info->li_list_mtx);
2913 	mutex_unlock(&ext4_li_mtx);
2914 }
2915 
2916 static struct task_struct *ext4_lazyinit_task;
2917 
2918 /*
2919  * This is the function where ext4lazyinit thread lives. It walks
2920  * through the request list searching for next scheduled filesystem.
2921  * When such a fs is found, run the lazy initialization request
2922  * (ext4_rn_li_request) and keep track of the time spend in this
2923  * function. Based on that time we compute next schedule time of
2924  * the request. When walking through the list is complete, compute
2925  * next waking time and put itself into sleep.
2926  */
2927 static int ext4_lazyinit_thread(void *arg)
2928 {
2929 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2930 	struct list_head *pos, *n;
2931 	struct ext4_li_request *elr;
2932 	unsigned long next_wakeup, cur;
2933 
2934 	BUG_ON(NULL == eli);
2935 
2936 cont_thread:
2937 	while (true) {
2938 		next_wakeup = MAX_JIFFY_OFFSET;
2939 
2940 		mutex_lock(&eli->li_list_mtx);
2941 		if (list_empty(&eli->li_request_list)) {
2942 			mutex_unlock(&eli->li_list_mtx);
2943 			goto exit_thread;
2944 		}
2945 
2946 		list_for_each_safe(pos, n, &eli->li_request_list) {
2947 			elr = list_entry(pos, struct ext4_li_request,
2948 					 lr_request);
2949 
2950 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2951 				if (ext4_run_li_request(elr) != 0) {
2952 					/* error, remove the lazy_init job */
2953 					ext4_remove_li_request(elr);
2954 					continue;
2955 				}
2956 			}
2957 
2958 			if (time_before(elr->lr_next_sched, next_wakeup))
2959 				next_wakeup = elr->lr_next_sched;
2960 		}
2961 		mutex_unlock(&eli->li_list_mtx);
2962 
2963 		try_to_freeze();
2964 
2965 		cur = jiffies;
2966 		if ((time_after_eq(cur, next_wakeup)) ||
2967 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2968 			cond_resched();
2969 			continue;
2970 		}
2971 
2972 		schedule_timeout_interruptible(next_wakeup - cur);
2973 
2974 		if (kthread_should_stop()) {
2975 			ext4_clear_request_list();
2976 			goto exit_thread;
2977 		}
2978 	}
2979 
2980 exit_thread:
2981 	/*
2982 	 * It looks like the request list is empty, but we need
2983 	 * to check it under the li_list_mtx lock, to prevent any
2984 	 * additions into it, and of course we should lock ext4_li_mtx
2985 	 * to atomically free the list and ext4_li_info, because at
2986 	 * this point another ext4 filesystem could be registering
2987 	 * new one.
2988 	 */
2989 	mutex_lock(&ext4_li_mtx);
2990 	mutex_lock(&eli->li_list_mtx);
2991 	if (!list_empty(&eli->li_request_list)) {
2992 		mutex_unlock(&eli->li_list_mtx);
2993 		mutex_unlock(&ext4_li_mtx);
2994 		goto cont_thread;
2995 	}
2996 	mutex_unlock(&eli->li_list_mtx);
2997 	kfree(ext4_li_info);
2998 	ext4_li_info = NULL;
2999 	mutex_unlock(&ext4_li_mtx);
3000 
3001 	return 0;
3002 }
3003 
3004 static void ext4_clear_request_list(void)
3005 {
3006 	struct list_head *pos, *n;
3007 	struct ext4_li_request *elr;
3008 
3009 	mutex_lock(&ext4_li_info->li_list_mtx);
3010 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3011 		elr = list_entry(pos, struct ext4_li_request,
3012 				 lr_request);
3013 		ext4_remove_li_request(elr);
3014 	}
3015 	mutex_unlock(&ext4_li_info->li_list_mtx);
3016 }
3017 
3018 static int ext4_run_lazyinit_thread(void)
3019 {
3020 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3021 					 ext4_li_info, "ext4lazyinit");
3022 	if (IS_ERR(ext4_lazyinit_task)) {
3023 		int err = PTR_ERR(ext4_lazyinit_task);
3024 		ext4_clear_request_list();
3025 		kfree(ext4_li_info);
3026 		ext4_li_info = NULL;
3027 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3028 				 "initialization thread\n",
3029 				 err);
3030 		return err;
3031 	}
3032 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3033 	return 0;
3034 }
3035 
3036 /*
3037  * Check whether it make sense to run itable init. thread or not.
3038  * If there is at least one uninitialized inode table, return
3039  * corresponding group number, else the loop goes through all
3040  * groups and return total number of groups.
3041  */
3042 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3043 {
3044 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3045 	struct ext4_group_desc *gdp = NULL;
3046 
3047 	for (group = 0; group < ngroups; group++) {
3048 		gdp = ext4_get_group_desc(sb, group, NULL);
3049 		if (!gdp)
3050 			continue;
3051 
3052 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3053 			break;
3054 	}
3055 
3056 	return group;
3057 }
3058 
3059 static int ext4_li_info_new(void)
3060 {
3061 	struct ext4_lazy_init *eli = NULL;
3062 
3063 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3064 	if (!eli)
3065 		return -ENOMEM;
3066 
3067 	INIT_LIST_HEAD(&eli->li_request_list);
3068 	mutex_init(&eli->li_list_mtx);
3069 
3070 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3071 
3072 	ext4_li_info = eli;
3073 
3074 	return 0;
3075 }
3076 
3077 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3078 					    ext4_group_t start)
3079 {
3080 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3081 	struct ext4_li_request *elr;
3082 
3083 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3084 	if (!elr)
3085 		return NULL;
3086 
3087 	elr->lr_super = sb;
3088 	elr->lr_sbi = sbi;
3089 	elr->lr_next_group = start;
3090 
3091 	/*
3092 	 * Randomize first schedule time of the request to
3093 	 * spread the inode table initialization requests
3094 	 * better.
3095 	 */
3096 	elr->lr_next_sched = jiffies + (prandom_u32() %
3097 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3098 	return elr;
3099 }
3100 
3101 int ext4_register_li_request(struct super_block *sb,
3102 			     ext4_group_t first_not_zeroed)
3103 {
3104 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3105 	struct ext4_li_request *elr = NULL;
3106 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3107 	int ret = 0;
3108 
3109 	mutex_lock(&ext4_li_mtx);
3110 	if (sbi->s_li_request != NULL) {
3111 		/*
3112 		 * Reset timeout so it can be computed again, because
3113 		 * s_li_wait_mult might have changed.
3114 		 */
3115 		sbi->s_li_request->lr_timeout = 0;
3116 		goto out;
3117 	}
3118 
3119 	if (first_not_zeroed == ngroups ||
3120 	    (sb->s_flags & MS_RDONLY) ||
3121 	    !test_opt(sb, INIT_INODE_TABLE))
3122 		goto out;
3123 
3124 	elr = ext4_li_request_new(sb, first_not_zeroed);
3125 	if (!elr) {
3126 		ret = -ENOMEM;
3127 		goto out;
3128 	}
3129 
3130 	if (NULL == ext4_li_info) {
3131 		ret = ext4_li_info_new();
3132 		if (ret)
3133 			goto out;
3134 	}
3135 
3136 	mutex_lock(&ext4_li_info->li_list_mtx);
3137 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3138 	mutex_unlock(&ext4_li_info->li_list_mtx);
3139 
3140 	sbi->s_li_request = elr;
3141 	/*
3142 	 * set elr to NULL here since it has been inserted to
3143 	 * the request_list and the removal and free of it is
3144 	 * handled by ext4_clear_request_list from now on.
3145 	 */
3146 	elr = NULL;
3147 
3148 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3149 		ret = ext4_run_lazyinit_thread();
3150 		if (ret)
3151 			goto out;
3152 	}
3153 out:
3154 	mutex_unlock(&ext4_li_mtx);
3155 	if (ret)
3156 		kfree(elr);
3157 	return ret;
3158 }
3159 
3160 /*
3161  * We do not need to lock anything since this is called on
3162  * module unload.
3163  */
3164 static void ext4_destroy_lazyinit_thread(void)
3165 {
3166 	/*
3167 	 * If thread exited earlier
3168 	 * there's nothing to be done.
3169 	 */
3170 	if (!ext4_li_info || !ext4_lazyinit_task)
3171 		return;
3172 
3173 	kthread_stop(ext4_lazyinit_task);
3174 }
3175 
3176 static int set_journal_csum_feature_set(struct super_block *sb)
3177 {
3178 	int ret = 1;
3179 	int compat, incompat;
3180 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3181 
3182 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3183 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3184 		/* journal checksum v2 */
3185 		compat = 0;
3186 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3187 	} else {
3188 		/* journal checksum v1 */
3189 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3190 		incompat = 0;
3191 	}
3192 
3193 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3194 		ret = jbd2_journal_set_features(sbi->s_journal,
3195 				compat, 0,
3196 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3197 				incompat);
3198 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3199 		ret = jbd2_journal_set_features(sbi->s_journal,
3200 				compat, 0,
3201 				incompat);
3202 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3203 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3204 	} else {
3205 		jbd2_journal_clear_features(sbi->s_journal,
3206 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3207 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3208 				JBD2_FEATURE_INCOMPAT_CSUM_V2);
3209 	}
3210 
3211 	return ret;
3212 }
3213 
3214 /*
3215  * Note: calculating the overhead so we can be compatible with
3216  * historical BSD practice is quite difficult in the face of
3217  * clusters/bigalloc.  This is because multiple metadata blocks from
3218  * different block group can end up in the same allocation cluster.
3219  * Calculating the exact overhead in the face of clustered allocation
3220  * requires either O(all block bitmaps) in memory or O(number of block
3221  * groups**2) in time.  We will still calculate the superblock for
3222  * older file systems --- and if we come across with a bigalloc file
3223  * system with zero in s_overhead_clusters the estimate will be close to
3224  * correct especially for very large cluster sizes --- but for newer
3225  * file systems, it's better to calculate this figure once at mkfs
3226  * time, and store it in the superblock.  If the superblock value is
3227  * present (even for non-bigalloc file systems), we will use it.
3228  */
3229 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3230 			  char *buf)
3231 {
3232 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3233 	struct ext4_group_desc	*gdp;
3234 	ext4_fsblk_t		first_block, last_block, b;
3235 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3236 	int			s, j, count = 0;
3237 
3238 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3239 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3240 			sbi->s_itb_per_group + 2);
3241 
3242 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3243 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3244 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3245 	for (i = 0; i < ngroups; i++) {
3246 		gdp = ext4_get_group_desc(sb, i, NULL);
3247 		b = ext4_block_bitmap(sb, gdp);
3248 		if (b >= first_block && b <= last_block) {
3249 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3250 			count++;
3251 		}
3252 		b = ext4_inode_bitmap(sb, gdp);
3253 		if (b >= first_block && b <= last_block) {
3254 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3255 			count++;
3256 		}
3257 		b = ext4_inode_table(sb, gdp);
3258 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3259 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3260 				int c = EXT4_B2C(sbi, b - first_block);
3261 				ext4_set_bit(c, buf);
3262 				count++;
3263 			}
3264 		if (i != grp)
3265 			continue;
3266 		s = 0;
3267 		if (ext4_bg_has_super(sb, grp)) {
3268 			ext4_set_bit(s++, buf);
3269 			count++;
3270 		}
3271 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3272 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3273 			count++;
3274 		}
3275 	}
3276 	if (!count)
3277 		return 0;
3278 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3279 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3280 }
3281 
3282 /*
3283  * Compute the overhead and stash it in sbi->s_overhead
3284  */
3285 int ext4_calculate_overhead(struct super_block *sb)
3286 {
3287 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3288 	struct ext4_super_block *es = sbi->s_es;
3289 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3290 	ext4_fsblk_t overhead = 0;
3291 	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3292 
3293 	if (!buf)
3294 		return -ENOMEM;
3295 
3296 	/*
3297 	 * Compute the overhead (FS structures).  This is constant
3298 	 * for a given filesystem unless the number of block groups
3299 	 * changes so we cache the previous value until it does.
3300 	 */
3301 
3302 	/*
3303 	 * All of the blocks before first_data_block are overhead
3304 	 */
3305 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3306 
3307 	/*
3308 	 * Add the overhead found in each block group
3309 	 */
3310 	for (i = 0; i < ngroups; i++) {
3311 		int blks;
3312 
3313 		blks = count_overhead(sb, i, buf);
3314 		overhead += blks;
3315 		if (blks)
3316 			memset(buf, 0, PAGE_SIZE);
3317 		cond_resched();
3318 	}
3319 	/* Add the journal blocks as well */
3320 	if (sbi->s_journal)
3321 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3322 
3323 	sbi->s_overhead = overhead;
3324 	smp_wmb();
3325 	free_page((unsigned long) buf);
3326 	return 0;
3327 }
3328 
3329 
3330 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3331 {
3332 	ext4_fsblk_t resv_clusters;
3333 
3334 	/*
3335 	 * There's no need to reserve anything when we aren't using extents.
3336 	 * The space estimates are exact, there are no unwritten extents,
3337 	 * hole punching doesn't need new metadata... This is needed especially
3338 	 * to keep ext2/3 backward compatibility.
3339 	 */
3340 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3341 		return 0;
3342 	/*
3343 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3344 	 * This should cover the situations where we can not afford to run
3345 	 * out of space like for example punch hole, or converting
3346 	 * unwritten extents in delalloc path. In most cases such
3347 	 * allocation would require 1, or 2 blocks, higher numbers are
3348 	 * very rare.
3349 	 */
3350 	resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3351 			EXT4_SB(sb)->s_cluster_bits;
3352 
3353 	do_div(resv_clusters, 50);
3354 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3355 
3356 	return resv_clusters;
3357 }
3358 
3359 
3360 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3361 {
3362 	ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3363 				sbi->s_cluster_bits;
3364 
3365 	if (count >= clusters)
3366 		return -EINVAL;
3367 
3368 	atomic64_set(&sbi->s_resv_clusters, count);
3369 	return 0;
3370 }
3371 
3372 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3373 {
3374 	char *orig_data = kstrdup(data, GFP_KERNEL);
3375 	struct buffer_head *bh;
3376 	struct ext4_super_block *es = NULL;
3377 	struct ext4_sb_info *sbi;
3378 	ext4_fsblk_t block;
3379 	ext4_fsblk_t sb_block = get_sb_block(&data);
3380 	ext4_fsblk_t logical_sb_block;
3381 	unsigned long offset = 0;
3382 	unsigned long journal_devnum = 0;
3383 	unsigned long def_mount_opts;
3384 	struct inode *root;
3385 	char *cp;
3386 	const char *descr;
3387 	int ret = -ENOMEM;
3388 	int blocksize, clustersize;
3389 	unsigned int db_count;
3390 	unsigned int i;
3391 	int needs_recovery, has_huge_files, has_bigalloc;
3392 	__u64 blocks_count;
3393 	int err = 0;
3394 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3395 	ext4_group_t first_not_zeroed;
3396 
3397 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3398 	if (!sbi)
3399 		goto out_free_orig;
3400 
3401 	sbi->s_blockgroup_lock =
3402 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3403 	if (!sbi->s_blockgroup_lock) {
3404 		kfree(sbi);
3405 		goto out_free_orig;
3406 	}
3407 	sb->s_fs_info = sbi;
3408 	sbi->s_sb = sb;
3409 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3410 	sbi->s_sb_block = sb_block;
3411 	if (sb->s_bdev->bd_part)
3412 		sbi->s_sectors_written_start =
3413 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3414 
3415 	/* Cleanup superblock name */
3416 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3417 		*cp = '!';
3418 
3419 	/* -EINVAL is default */
3420 	ret = -EINVAL;
3421 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3422 	if (!blocksize) {
3423 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3424 		goto out_fail;
3425 	}
3426 
3427 	/*
3428 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3429 	 * block sizes.  We need to calculate the offset from buffer start.
3430 	 */
3431 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3432 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3433 		offset = do_div(logical_sb_block, blocksize);
3434 	} else {
3435 		logical_sb_block = sb_block;
3436 	}
3437 
3438 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3439 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3440 		goto out_fail;
3441 	}
3442 	/*
3443 	 * Note: s_es must be initialized as soon as possible because
3444 	 *       some ext4 macro-instructions depend on its value
3445 	 */
3446 	es = (struct ext4_super_block *) (bh->b_data + offset);
3447 	sbi->s_es = es;
3448 	sb->s_magic = le16_to_cpu(es->s_magic);
3449 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3450 		goto cantfind_ext4;
3451 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3452 
3453 	/* Warn if metadata_csum and gdt_csum are both set. */
3454 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3455 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3456 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3457 		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3458 			     "redundant flags; please run fsck.");
3459 
3460 	/* Check for a known checksum algorithm */
3461 	if (!ext4_verify_csum_type(sb, es)) {
3462 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3463 			 "unknown checksum algorithm.");
3464 		silent = 1;
3465 		goto cantfind_ext4;
3466 	}
3467 
3468 	/* Load the checksum driver */
3469 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3470 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3471 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3472 		if (IS_ERR(sbi->s_chksum_driver)) {
3473 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3474 			ret = PTR_ERR(sbi->s_chksum_driver);
3475 			sbi->s_chksum_driver = NULL;
3476 			goto failed_mount;
3477 		}
3478 	}
3479 
3480 	/* Check superblock checksum */
3481 	if (!ext4_superblock_csum_verify(sb, es)) {
3482 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3483 			 "invalid superblock checksum.  Run e2fsck?");
3484 		silent = 1;
3485 		goto cantfind_ext4;
3486 	}
3487 
3488 	/* Precompute checksum seed for all metadata */
3489 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3490 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3491 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3492 					       sizeof(es->s_uuid));
3493 
3494 	/* Set defaults before we parse the mount options */
3495 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3496 	set_opt(sb, INIT_INODE_TABLE);
3497 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3498 		set_opt(sb, DEBUG);
3499 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3500 		set_opt(sb, GRPID);
3501 	if (def_mount_opts & EXT4_DEFM_UID16)
3502 		set_opt(sb, NO_UID32);
3503 	/* xattr user namespace & acls are now defaulted on */
3504 	set_opt(sb, XATTR_USER);
3505 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3506 	set_opt(sb, POSIX_ACL);
3507 #endif
3508 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3509 		set_opt(sb, JOURNAL_DATA);
3510 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3511 		set_opt(sb, ORDERED_DATA);
3512 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3513 		set_opt(sb, WRITEBACK_DATA);
3514 
3515 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3516 		set_opt(sb, ERRORS_PANIC);
3517 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3518 		set_opt(sb, ERRORS_CONT);
3519 	else
3520 		set_opt(sb, ERRORS_RO);
3521 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3522 		set_opt(sb, BLOCK_VALIDITY);
3523 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3524 		set_opt(sb, DISCARD);
3525 
3526 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3527 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3528 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3529 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3530 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3531 
3532 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3533 		set_opt(sb, BARRIER);
3534 
3535 	/*
3536 	 * enable delayed allocation by default
3537 	 * Use -o nodelalloc to turn it off
3538 	 */
3539 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3540 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3541 		set_opt(sb, DELALLOC);
3542 
3543 	/*
3544 	 * set default s_li_wait_mult for lazyinit, for the case there is
3545 	 * no mount option specified.
3546 	 */
3547 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3548 
3549 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3550 			   &journal_devnum, &journal_ioprio, 0)) {
3551 		ext4_msg(sb, KERN_WARNING,
3552 			 "failed to parse options in superblock: %s",
3553 			 sbi->s_es->s_mount_opts);
3554 	}
3555 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3556 	if (!parse_options((char *) data, sb, &journal_devnum,
3557 			   &journal_ioprio, 0))
3558 		goto failed_mount;
3559 
3560 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3561 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3562 			    "with data=journal disables delayed "
3563 			    "allocation and O_DIRECT support!\n");
3564 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3565 			ext4_msg(sb, KERN_ERR, "can't mount with "
3566 				 "both data=journal and delalloc");
3567 			goto failed_mount;
3568 		}
3569 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3570 			ext4_msg(sb, KERN_ERR, "can't mount with "
3571 				 "both data=journal and dioread_nolock");
3572 			goto failed_mount;
3573 		}
3574 		if (test_opt(sb, DELALLOC))
3575 			clear_opt(sb, DELALLOC);
3576 	}
3577 
3578 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3579 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3580 
3581 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3582 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3583 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3584 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3585 		ext4_msg(sb, KERN_WARNING,
3586 		       "feature flags set on rev 0 fs, "
3587 		       "running e2fsck is recommended");
3588 
3589 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3590 		set_opt2(sb, HURD_COMPAT);
3591 		if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3592 					      EXT4_FEATURE_INCOMPAT_64BIT)) {
3593 			ext4_msg(sb, KERN_ERR,
3594 				 "The Hurd can't support 64-bit file systems");
3595 			goto failed_mount;
3596 		}
3597 	}
3598 
3599 	if (IS_EXT2_SB(sb)) {
3600 		if (ext2_feature_set_ok(sb))
3601 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3602 				 "using the ext4 subsystem");
3603 		else {
3604 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3605 				 "to feature incompatibilities");
3606 			goto failed_mount;
3607 		}
3608 	}
3609 
3610 	if (IS_EXT3_SB(sb)) {
3611 		if (ext3_feature_set_ok(sb))
3612 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3613 				 "using the ext4 subsystem");
3614 		else {
3615 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3616 				 "to feature incompatibilities");
3617 			goto failed_mount;
3618 		}
3619 	}
3620 
3621 	/*
3622 	 * Check feature flags regardless of the revision level, since we
3623 	 * previously didn't change the revision level when setting the flags,
3624 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3625 	 */
3626 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3627 		goto failed_mount;
3628 
3629 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3630 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3631 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3632 		ext4_msg(sb, KERN_ERR,
3633 		       "Unsupported filesystem blocksize %d", blocksize);
3634 		goto failed_mount;
3635 	}
3636 
3637 	if (sb->s_blocksize != blocksize) {
3638 		/* Validate the filesystem blocksize */
3639 		if (!sb_set_blocksize(sb, blocksize)) {
3640 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3641 					blocksize);
3642 			goto failed_mount;
3643 		}
3644 
3645 		brelse(bh);
3646 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3647 		offset = do_div(logical_sb_block, blocksize);
3648 		bh = sb_bread(sb, logical_sb_block);
3649 		if (!bh) {
3650 			ext4_msg(sb, KERN_ERR,
3651 			       "Can't read superblock on 2nd try");
3652 			goto failed_mount;
3653 		}
3654 		es = (struct ext4_super_block *)(bh->b_data + offset);
3655 		sbi->s_es = es;
3656 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3657 			ext4_msg(sb, KERN_ERR,
3658 			       "Magic mismatch, very weird!");
3659 			goto failed_mount;
3660 		}
3661 	}
3662 
3663 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3664 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3665 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3666 						      has_huge_files);
3667 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3668 
3669 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3670 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3671 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3672 	} else {
3673 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3674 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3675 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3676 		    (!is_power_of_2(sbi->s_inode_size)) ||
3677 		    (sbi->s_inode_size > blocksize)) {
3678 			ext4_msg(sb, KERN_ERR,
3679 			       "unsupported inode size: %d",
3680 			       sbi->s_inode_size);
3681 			goto failed_mount;
3682 		}
3683 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3684 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3685 	}
3686 
3687 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3688 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3689 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3690 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3691 		    !is_power_of_2(sbi->s_desc_size)) {
3692 			ext4_msg(sb, KERN_ERR,
3693 			       "unsupported descriptor size %lu",
3694 			       sbi->s_desc_size);
3695 			goto failed_mount;
3696 		}
3697 	} else
3698 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3699 
3700 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3701 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3702 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3703 		goto cantfind_ext4;
3704 
3705 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3706 	if (sbi->s_inodes_per_block == 0)
3707 		goto cantfind_ext4;
3708 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3709 					sbi->s_inodes_per_block;
3710 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3711 	sbi->s_sbh = bh;
3712 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3713 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3714 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3715 
3716 	for (i = 0; i < 4; i++)
3717 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3718 	sbi->s_def_hash_version = es->s_def_hash_version;
3719 	if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3720 		i = le32_to_cpu(es->s_flags);
3721 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3722 			sbi->s_hash_unsigned = 3;
3723 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3724 #ifdef __CHAR_UNSIGNED__
3725 			if (!(sb->s_flags & MS_RDONLY))
3726 				es->s_flags |=
3727 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3728 			sbi->s_hash_unsigned = 3;
3729 #else
3730 			if (!(sb->s_flags & MS_RDONLY))
3731 				es->s_flags |=
3732 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3733 #endif
3734 		}
3735 	}
3736 
3737 	/* Handle clustersize */
3738 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3739 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3740 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3741 	if (has_bigalloc) {
3742 		if (clustersize < blocksize) {
3743 			ext4_msg(sb, KERN_ERR,
3744 				 "cluster size (%d) smaller than "
3745 				 "block size (%d)", clustersize, blocksize);
3746 			goto failed_mount;
3747 		}
3748 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3749 			le32_to_cpu(es->s_log_block_size);
3750 		sbi->s_clusters_per_group =
3751 			le32_to_cpu(es->s_clusters_per_group);
3752 		if (sbi->s_clusters_per_group > blocksize * 8) {
3753 			ext4_msg(sb, KERN_ERR,
3754 				 "#clusters per group too big: %lu",
3755 				 sbi->s_clusters_per_group);
3756 			goto failed_mount;
3757 		}
3758 		if (sbi->s_blocks_per_group !=
3759 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3760 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3761 				 "clusters per group (%lu) inconsistent",
3762 				 sbi->s_blocks_per_group,
3763 				 sbi->s_clusters_per_group);
3764 			goto failed_mount;
3765 		}
3766 	} else {
3767 		if (clustersize != blocksize) {
3768 			ext4_warning(sb, "fragment/cluster size (%d) != "
3769 				     "block size (%d)", clustersize,
3770 				     blocksize);
3771 			clustersize = blocksize;
3772 		}
3773 		if (sbi->s_blocks_per_group > blocksize * 8) {
3774 			ext4_msg(sb, KERN_ERR,
3775 				 "#blocks per group too big: %lu",
3776 				 sbi->s_blocks_per_group);
3777 			goto failed_mount;
3778 		}
3779 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3780 		sbi->s_cluster_bits = 0;
3781 	}
3782 	sbi->s_cluster_ratio = clustersize / blocksize;
3783 
3784 	if (sbi->s_inodes_per_group > blocksize * 8) {
3785 		ext4_msg(sb, KERN_ERR,
3786 		       "#inodes per group too big: %lu",
3787 		       sbi->s_inodes_per_group);
3788 		goto failed_mount;
3789 	}
3790 
3791 	/* Do we have standard group size of clustersize * 8 blocks ? */
3792 	if (sbi->s_blocks_per_group == clustersize << 3)
3793 		set_opt2(sb, STD_GROUP_SIZE);
3794 
3795 	/*
3796 	 * Test whether we have more sectors than will fit in sector_t,
3797 	 * and whether the max offset is addressable by the page cache.
3798 	 */
3799 	err = generic_check_addressable(sb->s_blocksize_bits,
3800 					ext4_blocks_count(es));
3801 	if (err) {
3802 		ext4_msg(sb, KERN_ERR, "filesystem"
3803 			 " too large to mount safely on this system");
3804 		if (sizeof(sector_t) < 8)
3805 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3806 		goto failed_mount;
3807 	}
3808 
3809 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3810 		goto cantfind_ext4;
3811 
3812 	/* check blocks count against device size */
3813 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3814 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3815 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3816 		       "exceeds size of device (%llu blocks)",
3817 		       ext4_blocks_count(es), blocks_count);
3818 		goto failed_mount;
3819 	}
3820 
3821 	/*
3822 	 * It makes no sense for the first data block to be beyond the end
3823 	 * of the filesystem.
3824 	 */
3825 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3826 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3827 			 "block %u is beyond end of filesystem (%llu)",
3828 			 le32_to_cpu(es->s_first_data_block),
3829 			 ext4_blocks_count(es));
3830 		goto failed_mount;
3831 	}
3832 	blocks_count = (ext4_blocks_count(es) -
3833 			le32_to_cpu(es->s_first_data_block) +
3834 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3835 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3836 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3837 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3838 		       "(block count %llu, first data block %u, "
3839 		       "blocks per group %lu)", sbi->s_groups_count,
3840 		       ext4_blocks_count(es),
3841 		       le32_to_cpu(es->s_first_data_block),
3842 		       EXT4_BLOCKS_PER_GROUP(sb));
3843 		goto failed_mount;
3844 	}
3845 	sbi->s_groups_count = blocks_count;
3846 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3847 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3848 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3849 		   EXT4_DESC_PER_BLOCK(sb);
3850 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3851 					  sizeof(struct buffer_head *),
3852 					  GFP_KERNEL);
3853 	if (sbi->s_group_desc == NULL) {
3854 		ext4_msg(sb, KERN_ERR, "not enough memory");
3855 		ret = -ENOMEM;
3856 		goto failed_mount;
3857 	}
3858 
3859 	if (ext4_proc_root)
3860 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3861 
3862 	if (sbi->s_proc)
3863 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3864 				 &ext4_seq_options_fops, sb);
3865 
3866 	bgl_lock_init(sbi->s_blockgroup_lock);
3867 
3868 	for (i = 0; i < db_count; i++) {
3869 		block = descriptor_loc(sb, logical_sb_block, i);
3870 		sbi->s_group_desc[i] = sb_bread(sb, block);
3871 		if (!sbi->s_group_desc[i]) {
3872 			ext4_msg(sb, KERN_ERR,
3873 			       "can't read group descriptor %d", i);
3874 			db_count = i;
3875 			goto failed_mount2;
3876 		}
3877 	}
3878 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3879 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3880 		goto failed_mount2;
3881 	}
3882 
3883 	sbi->s_gdb_count = db_count;
3884 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3885 	spin_lock_init(&sbi->s_next_gen_lock);
3886 
3887 	init_timer(&sbi->s_err_report);
3888 	sbi->s_err_report.function = print_daily_error_info;
3889 	sbi->s_err_report.data = (unsigned long) sb;
3890 
3891 	/* Register extent status tree shrinker */
3892 	ext4_es_register_shrinker(sbi);
3893 
3894 	if ((err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0)) != 0) {
3895 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3896 		goto failed_mount3;
3897 	}
3898 
3899 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3900 	sbi->s_extent_max_zeroout_kb = 32;
3901 
3902 	/*
3903 	 * set up enough so that it can read an inode
3904 	 */
3905 	if (!test_opt(sb, NOLOAD) &&
3906 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3907 		sb->s_op = &ext4_sops;
3908 	else
3909 		sb->s_op = &ext4_nojournal_sops;
3910 	sb->s_export_op = &ext4_export_ops;
3911 	sb->s_xattr = ext4_xattr_handlers;
3912 #ifdef CONFIG_QUOTA
3913 	sb->dq_op = &ext4_quota_operations;
3914 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3915 		sb->s_qcop = &ext4_qctl_sysfile_operations;
3916 	else
3917 		sb->s_qcop = &ext4_qctl_operations;
3918 #endif
3919 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3920 
3921 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3922 	mutex_init(&sbi->s_orphan_lock);
3923 
3924 	sb->s_root = NULL;
3925 
3926 	needs_recovery = (es->s_last_orphan != 0 ||
3927 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3928 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3929 
3930 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3931 	    !(sb->s_flags & MS_RDONLY))
3932 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3933 			goto failed_mount3;
3934 
3935 	/*
3936 	 * The first inode we look at is the journal inode.  Don't try
3937 	 * root first: it may be modified in the journal!
3938 	 */
3939 	if (!test_opt(sb, NOLOAD) &&
3940 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3941 		if (ext4_load_journal(sb, es, journal_devnum))
3942 			goto failed_mount3;
3943 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3944 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3945 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3946 		       "suppressed and not mounted read-only");
3947 		goto failed_mount_wq;
3948 	} else {
3949 		clear_opt(sb, DATA_FLAGS);
3950 		sbi->s_journal = NULL;
3951 		needs_recovery = 0;
3952 		goto no_journal;
3953 	}
3954 
3955 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3956 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3957 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3958 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3959 		goto failed_mount_wq;
3960 	}
3961 
3962 	if (!set_journal_csum_feature_set(sb)) {
3963 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3964 			 "feature set");
3965 		goto failed_mount_wq;
3966 	}
3967 
3968 	/* We have now updated the journal if required, so we can
3969 	 * validate the data journaling mode. */
3970 	switch (test_opt(sb, DATA_FLAGS)) {
3971 	case 0:
3972 		/* No mode set, assume a default based on the journal
3973 		 * capabilities: ORDERED_DATA if the journal can
3974 		 * cope, else JOURNAL_DATA
3975 		 */
3976 		if (jbd2_journal_check_available_features
3977 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3978 			set_opt(sb, ORDERED_DATA);
3979 		else
3980 			set_opt(sb, JOURNAL_DATA);
3981 		break;
3982 
3983 	case EXT4_MOUNT_ORDERED_DATA:
3984 	case EXT4_MOUNT_WRITEBACK_DATA:
3985 		if (!jbd2_journal_check_available_features
3986 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3987 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3988 			       "requested data journaling mode");
3989 			goto failed_mount_wq;
3990 		}
3991 	default:
3992 		break;
3993 	}
3994 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3995 
3996 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3997 
3998 no_journal:
3999 	if (ext4_mballoc_ready) {
4000 		sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4001 		if (!sbi->s_mb_cache) {
4002 			ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4003 			goto failed_mount_wq;
4004 		}
4005 	}
4006 
4007 	/*
4008 	 * Get the # of file system overhead blocks from the
4009 	 * superblock if present.
4010 	 */
4011 	if (es->s_overhead_clusters)
4012 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4013 	else {
4014 		err = ext4_calculate_overhead(sb);
4015 		if (err)
4016 			goto failed_mount_wq;
4017 	}
4018 
4019 	/*
4020 	 * The maximum number of concurrent works can be high and
4021 	 * concurrency isn't really necessary.  Limit it to 1.
4022 	 */
4023 	EXT4_SB(sb)->rsv_conversion_wq =
4024 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4025 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4026 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4027 		ret = -ENOMEM;
4028 		goto failed_mount4;
4029 	}
4030 
4031 	/*
4032 	 * The jbd2_journal_load will have done any necessary log recovery,
4033 	 * so we can safely mount the rest of the filesystem now.
4034 	 */
4035 
4036 	root = ext4_iget(sb, EXT4_ROOT_INO);
4037 	if (IS_ERR(root)) {
4038 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4039 		ret = PTR_ERR(root);
4040 		root = NULL;
4041 		goto failed_mount4;
4042 	}
4043 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4044 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4045 		iput(root);
4046 		goto failed_mount4;
4047 	}
4048 	sb->s_root = d_make_root(root);
4049 	if (!sb->s_root) {
4050 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4051 		ret = -ENOMEM;
4052 		goto failed_mount4;
4053 	}
4054 
4055 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4056 		sb->s_flags |= MS_RDONLY;
4057 
4058 	/* determine the minimum size of new large inodes, if present */
4059 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4060 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4061 						     EXT4_GOOD_OLD_INODE_SIZE;
4062 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4063 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4064 			if (sbi->s_want_extra_isize <
4065 			    le16_to_cpu(es->s_want_extra_isize))
4066 				sbi->s_want_extra_isize =
4067 					le16_to_cpu(es->s_want_extra_isize);
4068 			if (sbi->s_want_extra_isize <
4069 			    le16_to_cpu(es->s_min_extra_isize))
4070 				sbi->s_want_extra_isize =
4071 					le16_to_cpu(es->s_min_extra_isize);
4072 		}
4073 	}
4074 	/* Check if enough inode space is available */
4075 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4076 							sbi->s_inode_size) {
4077 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4078 						       EXT4_GOOD_OLD_INODE_SIZE;
4079 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4080 			 "available");
4081 	}
4082 
4083 	err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4084 	if (err) {
4085 		ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4086 			 "reserved pool", ext4_calculate_resv_clusters(sb));
4087 		goto failed_mount4a;
4088 	}
4089 
4090 	err = ext4_setup_system_zone(sb);
4091 	if (err) {
4092 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4093 			 "zone (%d)", err);
4094 		goto failed_mount4a;
4095 	}
4096 
4097 	ext4_ext_init(sb);
4098 	err = ext4_mb_init(sb);
4099 	if (err) {
4100 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4101 			 err);
4102 		goto failed_mount5;
4103 	}
4104 
4105 	block = ext4_count_free_clusters(sb);
4106 	ext4_free_blocks_count_set(sbi->s_es,
4107 				   EXT4_C2B(sbi, block));
4108 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block);
4109 	if (!err) {
4110 		unsigned long freei = ext4_count_free_inodes(sb);
4111 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4112 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei);
4113 	}
4114 	if (!err)
4115 		err = percpu_counter_init(&sbi->s_dirs_counter,
4116 					  ext4_count_dirs(sb));
4117 	if (!err)
4118 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
4119 	if (err) {
4120 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4121 		goto failed_mount6;
4122 	}
4123 
4124 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
4125 		if (!ext4_fill_flex_info(sb)) {
4126 			ext4_msg(sb, KERN_ERR,
4127 			       "unable to initialize "
4128 			       "flex_bg meta info!");
4129 			goto failed_mount6;
4130 		}
4131 
4132 	err = ext4_register_li_request(sb, first_not_zeroed);
4133 	if (err)
4134 		goto failed_mount6;
4135 
4136 	sbi->s_kobj.kset = ext4_kset;
4137 	init_completion(&sbi->s_kobj_unregister);
4138 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4139 				   "%s", sb->s_id);
4140 	if (err)
4141 		goto failed_mount7;
4142 
4143 #ifdef CONFIG_QUOTA
4144 	/* Enable quota usage during mount. */
4145 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4146 	    !(sb->s_flags & MS_RDONLY)) {
4147 		err = ext4_enable_quotas(sb);
4148 		if (err)
4149 			goto failed_mount8;
4150 	}
4151 #endif  /* CONFIG_QUOTA */
4152 
4153 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4154 	ext4_orphan_cleanup(sb, es);
4155 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4156 	if (needs_recovery) {
4157 		ext4_msg(sb, KERN_INFO, "recovery complete");
4158 		ext4_mark_recovery_complete(sb, es);
4159 	}
4160 	if (EXT4_SB(sb)->s_journal) {
4161 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4162 			descr = " journalled data mode";
4163 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4164 			descr = " ordered data mode";
4165 		else
4166 			descr = " writeback data mode";
4167 	} else
4168 		descr = "out journal";
4169 
4170 	if (test_opt(sb, DISCARD)) {
4171 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4172 		if (!blk_queue_discard(q))
4173 			ext4_msg(sb, KERN_WARNING,
4174 				 "mounting with \"discard\" option, but "
4175 				 "the device does not support discard");
4176 	}
4177 
4178 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4179 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4180 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4181 
4182 	if (es->s_error_count)
4183 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4184 
4185 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4186 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4187 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4188 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4189 
4190 	kfree(orig_data);
4191 	return 0;
4192 
4193 cantfind_ext4:
4194 	if (!silent)
4195 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4196 	goto failed_mount;
4197 
4198 #ifdef CONFIG_QUOTA
4199 failed_mount8:
4200 	kobject_del(&sbi->s_kobj);
4201 #endif
4202 failed_mount7:
4203 	ext4_unregister_li_request(sb);
4204 failed_mount6:
4205 	ext4_mb_release(sb);
4206 	if (sbi->s_flex_groups)
4207 		ext4_kvfree(sbi->s_flex_groups);
4208 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4209 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4210 	percpu_counter_destroy(&sbi->s_dirs_counter);
4211 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4212 failed_mount5:
4213 	ext4_ext_release(sb);
4214 	ext4_release_system_zone(sb);
4215 failed_mount4a:
4216 	dput(sb->s_root);
4217 	sb->s_root = NULL;
4218 failed_mount4:
4219 	ext4_msg(sb, KERN_ERR, "mount failed");
4220 	if (EXT4_SB(sb)->rsv_conversion_wq)
4221 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4222 failed_mount_wq:
4223 	if (sbi->s_journal) {
4224 		jbd2_journal_destroy(sbi->s_journal);
4225 		sbi->s_journal = NULL;
4226 	}
4227 failed_mount3:
4228 	ext4_es_unregister_shrinker(sbi);
4229 	del_timer_sync(&sbi->s_err_report);
4230 	percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4231 	if (sbi->s_mmp_tsk)
4232 		kthread_stop(sbi->s_mmp_tsk);
4233 failed_mount2:
4234 	for (i = 0; i < db_count; i++)
4235 		brelse(sbi->s_group_desc[i]);
4236 	ext4_kvfree(sbi->s_group_desc);
4237 failed_mount:
4238 	if (sbi->s_chksum_driver)
4239 		crypto_free_shash(sbi->s_chksum_driver);
4240 	if (sbi->s_proc) {
4241 		remove_proc_entry("options", sbi->s_proc);
4242 		remove_proc_entry(sb->s_id, ext4_proc_root);
4243 	}
4244 #ifdef CONFIG_QUOTA
4245 	for (i = 0; i < MAXQUOTAS; i++)
4246 		kfree(sbi->s_qf_names[i]);
4247 #endif
4248 	ext4_blkdev_remove(sbi);
4249 	brelse(bh);
4250 out_fail:
4251 	sb->s_fs_info = NULL;
4252 	kfree(sbi->s_blockgroup_lock);
4253 	kfree(sbi);
4254 out_free_orig:
4255 	kfree(orig_data);
4256 	return err ? err : ret;
4257 }
4258 
4259 /*
4260  * Setup any per-fs journal parameters now.  We'll do this both on
4261  * initial mount, once the journal has been initialised but before we've
4262  * done any recovery; and again on any subsequent remount.
4263  */
4264 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4265 {
4266 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4267 
4268 	journal->j_commit_interval = sbi->s_commit_interval;
4269 	journal->j_min_batch_time = sbi->s_min_batch_time;
4270 	journal->j_max_batch_time = sbi->s_max_batch_time;
4271 
4272 	write_lock(&journal->j_state_lock);
4273 	if (test_opt(sb, BARRIER))
4274 		journal->j_flags |= JBD2_BARRIER;
4275 	else
4276 		journal->j_flags &= ~JBD2_BARRIER;
4277 	if (test_opt(sb, DATA_ERR_ABORT))
4278 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4279 	else
4280 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4281 	write_unlock(&journal->j_state_lock);
4282 }
4283 
4284 static journal_t *ext4_get_journal(struct super_block *sb,
4285 				   unsigned int journal_inum)
4286 {
4287 	struct inode *journal_inode;
4288 	journal_t *journal;
4289 
4290 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4291 
4292 	/* First, test for the existence of a valid inode on disk.  Bad
4293 	 * things happen if we iget() an unused inode, as the subsequent
4294 	 * iput() will try to delete it. */
4295 
4296 	journal_inode = ext4_iget(sb, journal_inum);
4297 	if (IS_ERR(journal_inode)) {
4298 		ext4_msg(sb, KERN_ERR, "no journal found");
4299 		return NULL;
4300 	}
4301 	if (!journal_inode->i_nlink) {
4302 		make_bad_inode(journal_inode);
4303 		iput(journal_inode);
4304 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4305 		return NULL;
4306 	}
4307 
4308 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4309 		  journal_inode, journal_inode->i_size);
4310 	if (!S_ISREG(journal_inode->i_mode)) {
4311 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4312 		iput(journal_inode);
4313 		return NULL;
4314 	}
4315 
4316 	journal = jbd2_journal_init_inode(journal_inode);
4317 	if (!journal) {
4318 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4319 		iput(journal_inode);
4320 		return NULL;
4321 	}
4322 	journal->j_private = sb;
4323 	ext4_init_journal_params(sb, journal);
4324 	return journal;
4325 }
4326 
4327 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4328 				       dev_t j_dev)
4329 {
4330 	struct buffer_head *bh;
4331 	journal_t *journal;
4332 	ext4_fsblk_t start;
4333 	ext4_fsblk_t len;
4334 	int hblock, blocksize;
4335 	ext4_fsblk_t sb_block;
4336 	unsigned long offset;
4337 	struct ext4_super_block *es;
4338 	struct block_device *bdev;
4339 
4340 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4341 
4342 	bdev = ext4_blkdev_get(j_dev, sb);
4343 	if (bdev == NULL)
4344 		return NULL;
4345 
4346 	blocksize = sb->s_blocksize;
4347 	hblock = bdev_logical_block_size(bdev);
4348 	if (blocksize < hblock) {
4349 		ext4_msg(sb, KERN_ERR,
4350 			"blocksize too small for journal device");
4351 		goto out_bdev;
4352 	}
4353 
4354 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4355 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4356 	set_blocksize(bdev, blocksize);
4357 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4358 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4359 		       "external journal");
4360 		goto out_bdev;
4361 	}
4362 
4363 	es = (struct ext4_super_block *) (bh->b_data + offset);
4364 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4365 	    !(le32_to_cpu(es->s_feature_incompat) &
4366 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4367 		ext4_msg(sb, KERN_ERR, "external journal has "
4368 					"bad superblock");
4369 		brelse(bh);
4370 		goto out_bdev;
4371 	}
4372 
4373 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4374 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4375 		brelse(bh);
4376 		goto out_bdev;
4377 	}
4378 
4379 	len = ext4_blocks_count(es);
4380 	start = sb_block + 1;
4381 	brelse(bh);	/* we're done with the superblock */
4382 
4383 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4384 					start, len, blocksize);
4385 	if (!journal) {
4386 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4387 		goto out_bdev;
4388 	}
4389 	journal->j_private = sb;
4390 	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4391 	wait_on_buffer(journal->j_sb_buffer);
4392 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4393 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4394 		goto out_journal;
4395 	}
4396 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4397 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4398 					"user (unsupported) - %d",
4399 			be32_to_cpu(journal->j_superblock->s_nr_users));
4400 		goto out_journal;
4401 	}
4402 	EXT4_SB(sb)->journal_bdev = bdev;
4403 	ext4_init_journal_params(sb, journal);
4404 	return journal;
4405 
4406 out_journal:
4407 	jbd2_journal_destroy(journal);
4408 out_bdev:
4409 	ext4_blkdev_put(bdev);
4410 	return NULL;
4411 }
4412 
4413 static int ext4_load_journal(struct super_block *sb,
4414 			     struct ext4_super_block *es,
4415 			     unsigned long journal_devnum)
4416 {
4417 	journal_t *journal;
4418 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4419 	dev_t journal_dev;
4420 	int err = 0;
4421 	int really_read_only;
4422 
4423 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4424 
4425 	if (journal_devnum &&
4426 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4427 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4428 			"numbers have changed");
4429 		journal_dev = new_decode_dev(journal_devnum);
4430 	} else
4431 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4432 
4433 	really_read_only = bdev_read_only(sb->s_bdev);
4434 
4435 	/*
4436 	 * Are we loading a blank journal or performing recovery after a
4437 	 * crash?  For recovery, we need to check in advance whether we
4438 	 * can get read-write access to the device.
4439 	 */
4440 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4441 		if (sb->s_flags & MS_RDONLY) {
4442 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4443 					"required on readonly filesystem");
4444 			if (really_read_only) {
4445 				ext4_msg(sb, KERN_ERR, "write access "
4446 					"unavailable, cannot proceed");
4447 				return -EROFS;
4448 			}
4449 			ext4_msg(sb, KERN_INFO, "write access will "
4450 			       "be enabled during recovery");
4451 		}
4452 	}
4453 
4454 	if (journal_inum && journal_dev) {
4455 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4456 		       "and inode journals!");
4457 		return -EINVAL;
4458 	}
4459 
4460 	if (journal_inum) {
4461 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4462 			return -EINVAL;
4463 	} else {
4464 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4465 			return -EINVAL;
4466 	}
4467 
4468 	if (!(journal->j_flags & JBD2_BARRIER))
4469 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4470 
4471 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4472 		err = jbd2_journal_wipe(journal, !really_read_only);
4473 	if (!err) {
4474 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4475 		if (save)
4476 			memcpy(save, ((char *) es) +
4477 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4478 		err = jbd2_journal_load(journal);
4479 		if (save)
4480 			memcpy(((char *) es) + EXT4_S_ERR_START,
4481 			       save, EXT4_S_ERR_LEN);
4482 		kfree(save);
4483 	}
4484 
4485 	if (err) {
4486 		ext4_msg(sb, KERN_ERR, "error loading journal");
4487 		jbd2_journal_destroy(journal);
4488 		return err;
4489 	}
4490 
4491 	EXT4_SB(sb)->s_journal = journal;
4492 	ext4_clear_journal_err(sb, es);
4493 
4494 	if (!really_read_only && journal_devnum &&
4495 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4496 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4497 
4498 		/* Make sure we flush the recovery flag to disk. */
4499 		ext4_commit_super(sb, 1);
4500 	}
4501 
4502 	return 0;
4503 }
4504 
4505 static int ext4_commit_super(struct super_block *sb, int sync)
4506 {
4507 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4508 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4509 	int error = 0;
4510 
4511 	if (!sbh || block_device_ejected(sb))
4512 		return error;
4513 	if (buffer_write_io_error(sbh)) {
4514 		/*
4515 		 * Oh, dear.  A previous attempt to write the
4516 		 * superblock failed.  This could happen because the
4517 		 * USB device was yanked out.  Or it could happen to
4518 		 * be a transient write error and maybe the block will
4519 		 * be remapped.  Nothing we can do but to retry the
4520 		 * write and hope for the best.
4521 		 */
4522 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4523 		       "superblock detected");
4524 		clear_buffer_write_io_error(sbh);
4525 		set_buffer_uptodate(sbh);
4526 	}
4527 	/*
4528 	 * If the file system is mounted read-only, don't update the
4529 	 * superblock write time.  This avoids updating the superblock
4530 	 * write time when we are mounting the root file system
4531 	 * read/only but we need to replay the journal; at that point,
4532 	 * for people who are east of GMT and who make their clock
4533 	 * tick in localtime for Windows bug-for-bug compatibility,
4534 	 * the clock is set in the future, and this will cause e2fsck
4535 	 * to complain and force a full file system check.
4536 	 */
4537 	if (!(sb->s_flags & MS_RDONLY))
4538 		es->s_wtime = cpu_to_le32(get_seconds());
4539 	if (sb->s_bdev->bd_part)
4540 		es->s_kbytes_written =
4541 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4542 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4543 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4544 	else
4545 		es->s_kbytes_written =
4546 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4547 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4548 		ext4_free_blocks_count_set(es,
4549 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4550 				&EXT4_SB(sb)->s_freeclusters_counter)));
4551 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4552 		es->s_free_inodes_count =
4553 			cpu_to_le32(percpu_counter_sum_positive(
4554 				&EXT4_SB(sb)->s_freeinodes_counter));
4555 	BUFFER_TRACE(sbh, "marking dirty");
4556 	ext4_superblock_csum_set(sb);
4557 	mark_buffer_dirty(sbh);
4558 	if (sync) {
4559 		error = sync_dirty_buffer(sbh);
4560 		if (error)
4561 			return error;
4562 
4563 		error = buffer_write_io_error(sbh);
4564 		if (error) {
4565 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4566 			       "superblock");
4567 			clear_buffer_write_io_error(sbh);
4568 			set_buffer_uptodate(sbh);
4569 		}
4570 	}
4571 	return error;
4572 }
4573 
4574 /*
4575  * Have we just finished recovery?  If so, and if we are mounting (or
4576  * remounting) the filesystem readonly, then we will end up with a
4577  * consistent fs on disk.  Record that fact.
4578  */
4579 static void ext4_mark_recovery_complete(struct super_block *sb,
4580 					struct ext4_super_block *es)
4581 {
4582 	journal_t *journal = EXT4_SB(sb)->s_journal;
4583 
4584 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4585 		BUG_ON(journal != NULL);
4586 		return;
4587 	}
4588 	jbd2_journal_lock_updates(journal);
4589 	if (jbd2_journal_flush(journal) < 0)
4590 		goto out;
4591 
4592 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4593 	    sb->s_flags & MS_RDONLY) {
4594 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4595 		ext4_commit_super(sb, 1);
4596 	}
4597 
4598 out:
4599 	jbd2_journal_unlock_updates(journal);
4600 }
4601 
4602 /*
4603  * If we are mounting (or read-write remounting) a filesystem whose journal
4604  * has recorded an error from a previous lifetime, move that error to the
4605  * main filesystem now.
4606  */
4607 static void ext4_clear_journal_err(struct super_block *sb,
4608 				   struct ext4_super_block *es)
4609 {
4610 	journal_t *journal;
4611 	int j_errno;
4612 	const char *errstr;
4613 
4614 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4615 
4616 	journal = EXT4_SB(sb)->s_journal;
4617 
4618 	/*
4619 	 * Now check for any error status which may have been recorded in the
4620 	 * journal by a prior ext4_error() or ext4_abort()
4621 	 */
4622 
4623 	j_errno = jbd2_journal_errno(journal);
4624 	if (j_errno) {
4625 		char nbuf[16];
4626 
4627 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4628 		ext4_warning(sb, "Filesystem error recorded "
4629 			     "from previous mount: %s", errstr);
4630 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4631 
4632 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4633 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4634 		ext4_commit_super(sb, 1);
4635 
4636 		jbd2_journal_clear_err(journal);
4637 		jbd2_journal_update_sb_errno(journal);
4638 	}
4639 }
4640 
4641 /*
4642  * Force the running and committing transactions to commit,
4643  * and wait on the commit.
4644  */
4645 int ext4_force_commit(struct super_block *sb)
4646 {
4647 	journal_t *journal;
4648 
4649 	if (sb->s_flags & MS_RDONLY)
4650 		return 0;
4651 
4652 	journal = EXT4_SB(sb)->s_journal;
4653 	return ext4_journal_force_commit(journal);
4654 }
4655 
4656 static int ext4_sync_fs(struct super_block *sb, int wait)
4657 {
4658 	int ret = 0;
4659 	tid_t target;
4660 	bool needs_barrier = false;
4661 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4662 
4663 	trace_ext4_sync_fs(sb, wait);
4664 	flush_workqueue(sbi->rsv_conversion_wq);
4665 	/*
4666 	 * Writeback quota in non-journalled quota case - journalled quota has
4667 	 * no dirty dquots
4668 	 */
4669 	dquot_writeback_dquots(sb, -1);
4670 	/*
4671 	 * Data writeback is possible w/o journal transaction, so barrier must
4672 	 * being sent at the end of the function. But we can skip it if
4673 	 * transaction_commit will do it for us.
4674 	 */
4675 	target = jbd2_get_latest_transaction(sbi->s_journal);
4676 	if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4677 	    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4678 		needs_barrier = true;
4679 
4680 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4681 		if (wait)
4682 			ret = jbd2_log_wait_commit(sbi->s_journal, target);
4683 	}
4684 	if (needs_barrier) {
4685 		int err;
4686 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4687 		if (!ret)
4688 			ret = err;
4689 	}
4690 
4691 	return ret;
4692 }
4693 
4694 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4695 {
4696 	int ret = 0;
4697 
4698 	trace_ext4_sync_fs(sb, wait);
4699 	flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4700 	dquot_writeback_dquots(sb, -1);
4701 	if (wait && test_opt(sb, BARRIER))
4702 		ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4703 
4704 	return ret;
4705 }
4706 
4707 /*
4708  * LVM calls this function before a (read-only) snapshot is created.  This
4709  * gives us a chance to flush the journal completely and mark the fs clean.
4710  *
4711  * Note that only this function cannot bring a filesystem to be in a clean
4712  * state independently. It relies on upper layer to stop all data & metadata
4713  * modifications.
4714  */
4715 static int ext4_freeze(struct super_block *sb)
4716 {
4717 	int error = 0;
4718 	journal_t *journal;
4719 
4720 	if (sb->s_flags & MS_RDONLY)
4721 		return 0;
4722 
4723 	journal = EXT4_SB(sb)->s_journal;
4724 
4725 	/* Now we set up the journal barrier. */
4726 	jbd2_journal_lock_updates(journal);
4727 
4728 	/*
4729 	 * Don't clear the needs_recovery flag if we failed to flush
4730 	 * the journal.
4731 	 */
4732 	error = jbd2_journal_flush(journal);
4733 	if (error < 0)
4734 		goto out;
4735 
4736 	/* Journal blocked and flushed, clear needs_recovery flag. */
4737 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4738 	error = ext4_commit_super(sb, 1);
4739 out:
4740 	/* we rely on upper layer to stop further updates */
4741 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4742 	return error;
4743 }
4744 
4745 /*
4746  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4747  * flag here, even though the filesystem is not technically dirty yet.
4748  */
4749 static int ext4_unfreeze(struct super_block *sb)
4750 {
4751 	if (sb->s_flags & MS_RDONLY)
4752 		return 0;
4753 
4754 	/* Reset the needs_recovery flag before the fs is unlocked. */
4755 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4756 	ext4_commit_super(sb, 1);
4757 	return 0;
4758 }
4759 
4760 /*
4761  * Structure to save mount options for ext4_remount's benefit
4762  */
4763 struct ext4_mount_options {
4764 	unsigned long s_mount_opt;
4765 	unsigned long s_mount_opt2;
4766 	kuid_t s_resuid;
4767 	kgid_t s_resgid;
4768 	unsigned long s_commit_interval;
4769 	u32 s_min_batch_time, s_max_batch_time;
4770 #ifdef CONFIG_QUOTA
4771 	int s_jquota_fmt;
4772 	char *s_qf_names[MAXQUOTAS];
4773 #endif
4774 };
4775 
4776 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4777 {
4778 	struct ext4_super_block *es;
4779 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4780 	unsigned long old_sb_flags;
4781 	struct ext4_mount_options old_opts;
4782 	int enable_quota = 0;
4783 	ext4_group_t g;
4784 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4785 	int err = 0;
4786 #ifdef CONFIG_QUOTA
4787 	int i, j;
4788 #endif
4789 	char *orig_data = kstrdup(data, GFP_KERNEL);
4790 
4791 	/* Store the original options */
4792 	old_sb_flags = sb->s_flags;
4793 	old_opts.s_mount_opt = sbi->s_mount_opt;
4794 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4795 	old_opts.s_resuid = sbi->s_resuid;
4796 	old_opts.s_resgid = sbi->s_resgid;
4797 	old_opts.s_commit_interval = sbi->s_commit_interval;
4798 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4799 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4800 #ifdef CONFIG_QUOTA
4801 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4802 	for (i = 0; i < MAXQUOTAS; i++)
4803 		if (sbi->s_qf_names[i]) {
4804 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4805 							 GFP_KERNEL);
4806 			if (!old_opts.s_qf_names[i]) {
4807 				for (j = 0; j < i; j++)
4808 					kfree(old_opts.s_qf_names[j]);
4809 				kfree(orig_data);
4810 				return -ENOMEM;
4811 			}
4812 		} else
4813 			old_opts.s_qf_names[i] = NULL;
4814 #endif
4815 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4816 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4817 
4818 	/*
4819 	 * Allow the "check" option to be passed as a remount option.
4820 	 */
4821 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4822 		err = -EINVAL;
4823 		goto restore_opts;
4824 	}
4825 
4826 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4827 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4828 			ext4_msg(sb, KERN_ERR, "can't mount with "
4829 				 "both data=journal and delalloc");
4830 			err = -EINVAL;
4831 			goto restore_opts;
4832 		}
4833 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4834 			ext4_msg(sb, KERN_ERR, "can't mount with "
4835 				 "both data=journal and dioread_nolock");
4836 			err = -EINVAL;
4837 			goto restore_opts;
4838 		}
4839 	}
4840 
4841 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4842 		ext4_abort(sb, "Abort forced by user");
4843 
4844 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4845 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4846 
4847 	es = sbi->s_es;
4848 
4849 	if (sbi->s_journal) {
4850 		ext4_init_journal_params(sb, sbi->s_journal);
4851 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4852 	}
4853 
4854 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4855 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4856 			err = -EROFS;
4857 			goto restore_opts;
4858 		}
4859 
4860 		if (*flags & MS_RDONLY) {
4861 			err = sync_filesystem(sb);
4862 			if (err < 0)
4863 				goto restore_opts;
4864 			err = dquot_suspend(sb, -1);
4865 			if (err < 0)
4866 				goto restore_opts;
4867 
4868 			/*
4869 			 * First of all, the unconditional stuff we have to do
4870 			 * to disable replay of the journal when we next remount
4871 			 */
4872 			sb->s_flags |= MS_RDONLY;
4873 
4874 			/*
4875 			 * OK, test if we are remounting a valid rw partition
4876 			 * readonly, and if so set the rdonly flag and then
4877 			 * mark the partition as valid again.
4878 			 */
4879 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4880 			    (sbi->s_mount_state & EXT4_VALID_FS))
4881 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4882 
4883 			if (sbi->s_journal)
4884 				ext4_mark_recovery_complete(sb, es);
4885 		} else {
4886 			/* Make sure we can mount this feature set readwrite */
4887 			if (!ext4_feature_set_ok(sb, 0)) {
4888 				err = -EROFS;
4889 				goto restore_opts;
4890 			}
4891 			/*
4892 			 * Make sure the group descriptor checksums
4893 			 * are sane.  If they aren't, refuse to remount r/w.
4894 			 */
4895 			for (g = 0; g < sbi->s_groups_count; g++) {
4896 				struct ext4_group_desc *gdp =
4897 					ext4_get_group_desc(sb, g, NULL);
4898 
4899 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4900 					ext4_msg(sb, KERN_ERR,
4901 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4902 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4903 					       le16_to_cpu(gdp->bg_checksum));
4904 					err = -EINVAL;
4905 					goto restore_opts;
4906 				}
4907 			}
4908 
4909 			/*
4910 			 * If we have an unprocessed orphan list hanging
4911 			 * around from a previously readonly bdev mount,
4912 			 * require a full umount/remount for now.
4913 			 */
4914 			if (es->s_last_orphan) {
4915 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4916 				       "remount RDWR because of unprocessed "
4917 				       "orphan inode list.  Please "
4918 				       "umount/remount instead");
4919 				err = -EINVAL;
4920 				goto restore_opts;
4921 			}
4922 
4923 			/*
4924 			 * Mounting a RDONLY partition read-write, so reread
4925 			 * and store the current valid flag.  (It may have
4926 			 * been changed by e2fsck since we originally mounted
4927 			 * the partition.)
4928 			 */
4929 			if (sbi->s_journal)
4930 				ext4_clear_journal_err(sb, es);
4931 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4932 			if (!ext4_setup_super(sb, es, 0))
4933 				sb->s_flags &= ~MS_RDONLY;
4934 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4935 						     EXT4_FEATURE_INCOMPAT_MMP))
4936 				if (ext4_multi_mount_protect(sb,
4937 						le64_to_cpu(es->s_mmp_block))) {
4938 					err = -EROFS;
4939 					goto restore_opts;
4940 				}
4941 			enable_quota = 1;
4942 		}
4943 	}
4944 
4945 	/*
4946 	 * Reinitialize lazy itable initialization thread based on
4947 	 * current settings
4948 	 */
4949 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4950 		ext4_unregister_li_request(sb);
4951 	else {
4952 		ext4_group_t first_not_zeroed;
4953 		first_not_zeroed = ext4_has_uninit_itable(sb);
4954 		ext4_register_li_request(sb, first_not_zeroed);
4955 	}
4956 
4957 	ext4_setup_system_zone(sb);
4958 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4959 		ext4_commit_super(sb, 1);
4960 
4961 #ifdef CONFIG_QUOTA
4962 	/* Release old quota file names */
4963 	for (i = 0; i < MAXQUOTAS; i++)
4964 		kfree(old_opts.s_qf_names[i]);
4965 	if (enable_quota) {
4966 		if (sb_any_quota_suspended(sb))
4967 			dquot_resume(sb, -1);
4968 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4969 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4970 			err = ext4_enable_quotas(sb);
4971 			if (err)
4972 				goto restore_opts;
4973 		}
4974 	}
4975 #endif
4976 
4977 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4978 	kfree(orig_data);
4979 	return 0;
4980 
4981 restore_opts:
4982 	sb->s_flags = old_sb_flags;
4983 	sbi->s_mount_opt = old_opts.s_mount_opt;
4984 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4985 	sbi->s_resuid = old_opts.s_resuid;
4986 	sbi->s_resgid = old_opts.s_resgid;
4987 	sbi->s_commit_interval = old_opts.s_commit_interval;
4988 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4989 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4990 #ifdef CONFIG_QUOTA
4991 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4992 	for (i = 0; i < MAXQUOTAS; i++) {
4993 		kfree(sbi->s_qf_names[i]);
4994 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4995 	}
4996 #endif
4997 	kfree(orig_data);
4998 	return err;
4999 }
5000 
5001 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5002 {
5003 	struct super_block *sb = dentry->d_sb;
5004 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5005 	struct ext4_super_block *es = sbi->s_es;
5006 	ext4_fsblk_t overhead = 0, resv_blocks;
5007 	u64 fsid;
5008 	s64 bfree;
5009 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5010 
5011 	if (!test_opt(sb, MINIX_DF))
5012 		overhead = sbi->s_overhead;
5013 
5014 	buf->f_type = EXT4_SUPER_MAGIC;
5015 	buf->f_bsize = sb->s_blocksize;
5016 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5017 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5018 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5019 	/* prevent underflow in case that few free space is available */
5020 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5021 	buf->f_bavail = buf->f_bfree -
5022 			(ext4_r_blocks_count(es) + resv_blocks);
5023 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5024 		buf->f_bavail = 0;
5025 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5026 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5027 	buf->f_namelen = EXT4_NAME_LEN;
5028 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5029 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5030 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5031 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5032 
5033 	return 0;
5034 }
5035 
5036 /* Helper function for writing quotas on sync - we need to start transaction
5037  * before quota file is locked for write. Otherwise the are possible deadlocks:
5038  * Process 1                         Process 2
5039  * ext4_create()                     quota_sync()
5040  *   jbd2_journal_start()                  write_dquot()
5041  *   dquot_initialize()                         down(dqio_mutex)
5042  *     down(dqio_mutex)                    jbd2_journal_start()
5043  *
5044  */
5045 
5046 #ifdef CONFIG_QUOTA
5047 
5048 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5049 {
5050 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5051 }
5052 
5053 static int ext4_write_dquot(struct dquot *dquot)
5054 {
5055 	int ret, err;
5056 	handle_t *handle;
5057 	struct inode *inode;
5058 
5059 	inode = dquot_to_inode(dquot);
5060 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5061 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5062 	if (IS_ERR(handle))
5063 		return PTR_ERR(handle);
5064 	ret = dquot_commit(dquot);
5065 	err = ext4_journal_stop(handle);
5066 	if (!ret)
5067 		ret = err;
5068 	return ret;
5069 }
5070 
5071 static int ext4_acquire_dquot(struct dquot *dquot)
5072 {
5073 	int ret, err;
5074 	handle_t *handle;
5075 
5076 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5077 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5078 	if (IS_ERR(handle))
5079 		return PTR_ERR(handle);
5080 	ret = dquot_acquire(dquot);
5081 	err = ext4_journal_stop(handle);
5082 	if (!ret)
5083 		ret = err;
5084 	return ret;
5085 }
5086 
5087 static int ext4_release_dquot(struct dquot *dquot)
5088 {
5089 	int ret, err;
5090 	handle_t *handle;
5091 
5092 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5093 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5094 	if (IS_ERR(handle)) {
5095 		/* Release dquot anyway to avoid endless cycle in dqput() */
5096 		dquot_release(dquot);
5097 		return PTR_ERR(handle);
5098 	}
5099 	ret = dquot_release(dquot);
5100 	err = ext4_journal_stop(handle);
5101 	if (!ret)
5102 		ret = err;
5103 	return ret;
5104 }
5105 
5106 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5107 {
5108 	struct super_block *sb = dquot->dq_sb;
5109 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5110 
5111 	/* Are we journaling quotas? */
5112 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5113 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5114 		dquot_mark_dquot_dirty(dquot);
5115 		return ext4_write_dquot(dquot);
5116 	} else {
5117 		return dquot_mark_dquot_dirty(dquot);
5118 	}
5119 }
5120 
5121 static int ext4_write_info(struct super_block *sb, int type)
5122 {
5123 	int ret, err;
5124 	handle_t *handle;
5125 
5126 	/* Data block + inode block */
5127 	handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5128 	if (IS_ERR(handle))
5129 		return PTR_ERR(handle);
5130 	ret = dquot_commit_info(sb, type);
5131 	err = ext4_journal_stop(handle);
5132 	if (!ret)
5133 		ret = err;
5134 	return ret;
5135 }
5136 
5137 /*
5138  * Turn on quotas during mount time - we need to find
5139  * the quota file and such...
5140  */
5141 static int ext4_quota_on_mount(struct super_block *sb, int type)
5142 {
5143 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5144 					EXT4_SB(sb)->s_jquota_fmt, type);
5145 }
5146 
5147 /*
5148  * Standard function to be called on quota_on
5149  */
5150 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5151 			 struct path *path)
5152 {
5153 	int err;
5154 
5155 	if (!test_opt(sb, QUOTA))
5156 		return -EINVAL;
5157 
5158 	/* Quotafile not on the same filesystem? */
5159 	if (path->dentry->d_sb != sb)
5160 		return -EXDEV;
5161 	/* Journaling quota? */
5162 	if (EXT4_SB(sb)->s_qf_names[type]) {
5163 		/* Quotafile not in fs root? */
5164 		if (path->dentry->d_parent != sb->s_root)
5165 			ext4_msg(sb, KERN_WARNING,
5166 				"Quota file not on filesystem root. "
5167 				"Journaled quota will not work");
5168 	}
5169 
5170 	/*
5171 	 * When we journal data on quota file, we have to flush journal to see
5172 	 * all updates to the file when we bypass pagecache...
5173 	 */
5174 	if (EXT4_SB(sb)->s_journal &&
5175 	    ext4_should_journal_data(path->dentry->d_inode)) {
5176 		/*
5177 		 * We don't need to lock updates but journal_flush() could
5178 		 * otherwise be livelocked...
5179 		 */
5180 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5181 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5182 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5183 		if (err)
5184 			return err;
5185 	}
5186 
5187 	return dquot_quota_on(sb, type, format_id, path);
5188 }
5189 
5190 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5191 			     unsigned int flags)
5192 {
5193 	int err;
5194 	struct inode *qf_inode;
5195 	unsigned long qf_inums[MAXQUOTAS] = {
5196 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5197 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5198 	};
5199 
5200 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5201 
5202 	if (!qf_inums[type])
5203 		return -EPERM;
5204 
5205 	qf_inode = ext4_iget(sb, qf_inums[type]);
5206 	if (IS_ERR(qf_inode)) {
5207 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5208 		return PTR_ERR(qf_inode);
5209 	}
5210 
5211 	/* Don't account quota for quota files to avoid recursion */
5212 	qf_inode->i_flags |= S_NOQUOTA;
5213 	err = dquot_enable(qf_inode, type, format_id, flags);
5214 	iput(qf_inode);
5215 
5216 	return err;
5217 }
5218 
5219 /* Enable usage tracking for all quota types. */
5220 static int ext4_enable_quotas(struct super_block *sb)
5221 {
5222 	int type, err = 0;
5223 	unsigned long qf_inums[MAXQUOTAS] = {
5224 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5225 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5226 	};
5227 
5228 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5229 	for (type = 0; type < MAXQUOTAS; type++) {
5230 		if (qf_inums[type]) {
5231 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5232 						DQUOT_USAGE_ENABLED);
5233 			if (err) {
5234 				ext4_warning(sb,
5235 					"Failed to enable quota tracking "
5236 					"(type=%d, err=%d). Please run "
5237 					"e2fsck to fix.", type, err);
5238 				return err;
5239 			}
5240 		}
5241 	}
5242 	return 0;
5243 }
5244 
5245 /*
5246  * quota_on function that is used when QUOTA feature is set.
5247  */
5248 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5249 				 int format_id)
5250 {
5251 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5252 		return -EINVAL;
5253 
5254 	/*
5255 	 * USAGE was enabled at mount time. Only need to enable LIMITS now.
5256 	 */
5257 	return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5258 }
5259 
5260 static int ext4_quota_off(struct super_block *sb, int type)
5261 {
5262 	struct inode *inode = sb_dqopt(sb)->files[type];
5263 	handle_t *handle;
5264 
5265 	/* Force all delayed allocation blocks to be allocated.
5266 	 * Caller already holds s_umount sem */
5267 	if (test_opt(sb, DELALLOC))
5268 		sync_filesystem(sb);
5269 
5270 	if (!inode)
5271 		goto out;
5272 
5273 	/* Update modification times of quota files when userspace can
5274 	 * start looking at them */
5275 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5276 	if (IS_ERR(handle))
5277 		goto out;
5278 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5279 	ext4_mark_inode_dirty(handle, inode);
5280 	ext4_journal_stop(handle);
5281 
5282 out:
5283 	return dquot_quota_off(sb, type);
5284 }
5285 
5286 /*
5287  * quota_off function that is used when QUOTA feature is set.
5288  */
5289 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5290 {
5291 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5292 		return -EINVAL;
5293 
5294 	/* Disable only the limits. */
5295 	return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5296 }
5297 
5298 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5299  * acquiring the locks... As quota files are never truncated and quota code
5300  * itself serializes the operations (and no one else should touch the files)
5301  * we don't have to be afraid of races */
5302 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5303 			       size_t len, loff_t off)
5304 {
5305 	struct inode *inode = sb_dqopt(sb)->files[type];
5306 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5307 	int err = 0;
5308 	int offset = off & (sb->s_blocksize - 1);
5309 	int tocopy;
5310 	size_t toread;
5311 	struct buffer_head *bh;
5312 	loff_t i_size = i_size_read(inode);
5313 
5314 	if (off > i_size)
5315 		return 0;
5316 	if (off+len > i_size)
5317 		len = i_size-off;
5318 	toread = len;
5319 	while (toread > 0) {
5320 		tocopy = sb->s_blocksize - offset < toread ?
5321 				sb->s_blocksize - offset : toread;
5322 		bh = ext4_bread(NULL, inode, blk, 0, &err);
5323 		if (err)
5324 			return err;
5325 		if (!bh)	/* A hole? */
5326 			memset(data, 0, tocopy);
5327 		else
5328 			memcpy(data, bh->b_data+offset, tocopy);
5329 		brelse(bh);
5330 		offset = 0;
5331 		toread -= tocopy;
5332 		data += tocopy;
5333 		blk++;
5334 	}
5335 	return len;
5336 }
5337 
5338 /* Write to quotafile (we know the transaction is already started and has
5339  * enough credits) */
5340 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5341 				const char *data, size_t len, loff_t off)
5342 {
5343 	struct inode *inode = sb_dqopt(sb)->files[type];
5344 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5345 	int err = 0;
5346 	int offset = off & (sb->s_blocksize - 1);
5347 	struct buffer_head *bh;
5348 	handle_t *handle = journal_current_handle();
5349 
5350 	if (EXT4_SB(sb)->s_journal && !handle) {
5351 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5352 			" cancelled because transaction is not started",
5353 			(unsigned long long)off, (unsigned long long)len);
5354 		return -EIO;
5355 	}
5356 	/*
5357 	 * Since we account only one data block in transaction credits,
5358 	 * then it is impossible to cross a block boundary.
5359 	 */
5360 	if (sb->s_blocksize - offset < len) {
5361 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5362 			" cancelled because not block aligned",
5363 			(unsigned long long)off, (unsigned long long)len);
5364 		return -EIO;
5365 	}
5366 
5367 	bh = ext4_bread(handle, inode, blk, 1, &err);
5368 	if (!bh)
5369 		goto out;
5370 	BUFFER_TRACE(bh, "get write access");
5371 	err = ext4_journal_get_write_access(handle, bh);
5372 	if (err) {
5373 		brelse(bh);
5374 		goto out;
5375 	}
5376 	lock_buffer(bh);
5377 	memcpy(bh->b_data+offset, data, len);
5378 	flush_dcache_page(bh->b_page);
5379 	unlock_buffer(bh);
5380 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5381 	brelse(bh);
5382 out:
5383 	if (err)
5384 		return err;
5385 	if (inode->i_size < off + len) {
5386 		i_size_write(inode, off + len);
5387 		EXT4_I(inode)->i_disksize = inode->i_size;
5388 		ext4_mark_inode_dirty(handle, inode);
5389 	}
5390 	return len;
5391 }
5392 
5393 #endif
5394 
5395 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5396 		       const char *dev_name, void *data)
5397 {
5398 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5399 }
5400 
5401 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5402 static inline void register_as_ext2(void)
5403 {
5404 	int err = register_filesystem(&ext2_fs_type);
5405 	if (err)
5406 		printk(KERN_WARNING
5407 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5408 }
5409 
5410 static inline void unregister_as_ext2(void)
5411 {
5412 	unregister_filesystem(&ext2_fs_type);
5413 }
5414 
5415 static inline int ext2_feature_set_ok(struct super_block *sb)
5416 {
5417 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5418 		return 0;
5419 	if (sb->s_flags & MS_RDONLY)
5420 		return 1;
5421 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5422 		return 0;
5423 	return 1;
5424 }
5425 #else
5426 static inline void register_as_ext2(void) { }
5427 static inline void unregister_as_ext2(void) { }
5428 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5429 #endif
5430 
5431 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5432 static inline void register_as_ext3(void)
5433 {
5434 	int err = register_filesystem(&ext3_fs_type);
5435 	if (err)
5436 		printk(KERN_WARNING
5437 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5438 }
5439 
5440 static inline void unregister_as_ext3(void)
5441 {
5442 	unregister_filesystem(&ext3_fs_type);
5443 }
5444 
5445 static inline int ext3_feature_set_ok(struct super_block *sb)
5446 {
5447 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5448 		return 0;
5449 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5450 		return 0;
5451 	if (sb->s_flags & MS_RDONLY)
5452 		return 1;
5453 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5454 		return 0;
5455 	return 1;
5456 }
5457 #else
5458 static inline void register_as_ext3(void) { }
5459 static inline void unregister_as_ext3(void) { }
5460 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5461 #endif
5462 
5463 static struct file_system_type ext4_fs_type = {
5464 	.owner		= THIS_MODULE,
5465 	.name		= "ext4",
5466 	.mount		= ext4_mount,
5467 	.kill_sb	= kill_block_super,
5468 	.fs_flags	= FS_REQUIRES_DEV,
5469 };
5470 MODULE_ALIAS_FS("ext4");
5471 
5472 static int __init ext4_init_feat_adverts(void)
5473 {
5474 	struct ext4_features *ef;
5475 	int ret = -ENOMEM;
5476 
5477 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5478 	if (!ef)
5479 		goto out;
5480 
5481 	ef->f_kobj.kset = ext4_kset;
5482 	init_completion(&ef->f_kobj_unregister);
5483 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5484 				   "features");
5485 	if (ret) {
5486 		kfree(ef);
5487 		goto out;
5488 	}
5489 
5490 	ext4_feat = ef;
5491 	ret = 0;
5492 out:
5493 	return ret;
5494 }
5495 
5496 static void ext4_exit_feat_adverts(void)
5497 {
5498 	kobject_put(&ext4_feat->f_kobj);
5499 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5500 	kfree(ext4_feat);
5501 }
5502 
5503 /* Shared across all ext4 file systems */
5504 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5505 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5506 
5507 static int __init ext4_init_fs(void)
5508 {
5509 	int i, err;
5510 
5511 	ext4_li_info = NULL;
5512 	mutex_init(&ext4_li_mtx);
5513 
5514 	/* Build-time check for flags consistency */
5515 	ext4_check_flag_values();
5516 
5517 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5518 		mutex_init(&ext4__aio_mutex[i]);
5519 		init_waitqueue_head(&ext4__ioend_wq[i]);
5520 	}
5521 
5522 	err = ext4_init_es();
5523 	if (err)
5524 		return err;
5525 
5526 	err = ext4_init_pageio();
5527 	if (err)
5528 		goto out7;
5529 
5530 	err = ext4_init_system_zone();
5531 	if (err)
5532 		goto out6;
5533 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5534 	if (!ext4_kset) {
5535 		err = -ENOMEM;
5536 		goto out5;
5537 	}
5538 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5539 
5540 	err = ext4_init_feat_adverts();
5541 	if (err)
5542 		goto out4;
5543 
5544 	err = ext4_init_mballoc();
5545 	if (err)
5546 		goto out2;
5547 	else
5548 		ext4_mballoc_ready = 1;
5549 	err = init_inodecache();
5550 	if (err)
5551 		goto out1;
5552 	register_as_ext3();
5553 	register_as_ext2();
5554 	err = register_filesystem(&ext4_fs_type);
5555 	if (err)
5556 		goto out;
5557 
5558 	return 0;
5559 out:
5560 	unregister_as_ext2();
5561 	unregister_as_ext3();
5562 	destroy_inodecache();
5563 out1:
5564 	ext4_mballoc_ready = 0;
5565 	ext4_exit_mballoc();
5566 out2:
5567 	ext4_exit_feat_adverts();
5568 out4:
5569 	if (ext4_proc_root)
5570 		remove_proc_entry("fs/ext4", NULL);
5571 	kset_unregister(ext4_kset);
5572 out5:
5573 	ext4_exit_system_zone();
5574 out6:
5575 	ext4_exit_pageio();
5576 out7:
5577 	ext4_exit_es();
5578 
5579 	return err;
5580 }
5581 
5582 static void __exit ext4_exit_fs(void)
5583 {
5584 	ext4_destroy_lazyinit_thread();
5585 	unregister_as_ext2();
5586 	unregister_as_ext3();
5587 	unregister_filesystem(&ext4_fs_type);
5588 	destroy_inodecache();
5589 	ext4_exit_mballoc();
5590 	ext4_exit_feat_adverts();
5591 	remove_proc_entry("fs/ext4", NULL);
5592 	kset_unregister(ext4_kset);
5593 	ext4_exit_system_zone();
5594 	ext4_exit_pageio();
5595 	ext4_exit_es();
5596 }
5597 
5598 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5599 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5600 MODULE_LICENSE("GPL");
5601 module_init(ext4_init_fs)
5602 module_exit(ext4_exit_fs)
5603