xref: /openbmc/linux/fs/ext4/super.c (revision f7018c21)
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 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 	INIT_LIST_HEAD(&ei->i_prealloc_list);
883 	spin_lock_init(&ei->i_prealloc_lock);
884 	ext4_es_init_tree(&ei->i_es_tree);
885 	rwlock_init(&ei->i_es_lock);
886 	INIT_LIST_HEAD(&ei->i_es_lru);
887 	ei->i_es_lru_nr = 0;
888 	ei->i_touch_when = 0;
889 	ei->i_reserved_data_blocks = 0;
890 	ei->i_reserved_meta_blocks = 0;
891 	ei->i_allocated_meta_blocks = 0;
892 	ei->i_da_metadata_calc_len = 0;
893 	ei->i_da_metadata_calc_last_lblock = 0;
894 	spin_lock_init(&(ei->i_block_reservation_lock));
895 #ifdef CONFIG_QUOTA
896 	ei->i_reserved_quota = 0;
897 #endif
898 	ei->jinode = NULL;
899 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
900 	spin_lock_init(&ei->i_completed_io_lock);
901 	ei->i_sync_tid = 0;
902 	ei->i_datasync_tid = 0;
903 	atomic_set(&ei->i_ioend_count, 0);
904 	atomic_set(&ei->i_unwritten, 0);
905 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
906 
907 	return &ei->vfs_inode;
908 }
909 
910 static int ext4_drop_inode(struct inode *inode)
911 {
912 	int drop = generic_drop_inode(inode);
913 
914 	trace_ext4_drop_inode(inode, drop);
915 	return drop;
916 }
917 
918 static void ext4_i_callback(struct rcu_head *head)
919 {
920 	struct inode *inode = container_of(head, struct inode, i_rcu);
921 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
922 }
923 
924 static void ext4_destroy_inode(struct inode *inode)
925 {
926 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
927 		ext4_msg(inode->i_sb, KERN_ERR,
928 			 "Inode %lu (%p): orphan list check failed!",
929 			 inode->i_ino, EXT4_I(inode));
930 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
931 				EXT4_I(inode), sizeof(struct ext4_inode_info),
932 				true);
933 		dump_stack();
934 	}
935 	call_rcu(&inode->i_rcu, ext4_i_callback);
936 }
937 
938 static void init_once(void *foo)
939 {
940 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
941 
942 	INIT_LIST_HEAD(&ei->i_orphan);
943 	init_rwsem(&ei->xattr_sem);
944 	init_rwsem(&ei->i_data_sem);
945 	inode_init_once(&ei->vfs_inode);
946 }
947 
948 static int __init init_inodecache(void)
949 {
950 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
951 					     sizeof(struct ext4_inode_info),
952 					     0, (SLAB_RECLAIM_ACCOUNT|
953 						SLAB_MEM_SPREAD),
954 					     init_once);
955 	if (ext4_inode_cachep == NULL)
956 		return -ENOMEM;
957 	return 0;
958 }
959 
960 static void destroy_inodecache(void)
961 {
962 	/*
963 	 * Make sure all delayed rcu free inodes are flushed before we
964 	 * destroy cache.
965 	 */
966 	rcu_barrier();
967 	kmem_cache_destroy(ext4_inode_cachep);
968 }
969 
970 void ext4_clear_inode(struct inode *inode)
971 {
972 	invalidate_inode_buffers(inode);
973 	clear_inode(inode);
974 	dquot_drop(inode);
975 	ext4_discard_preallocations(inode);
976 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
977 	ext4_es_lru_del(inode);
978 	if (EXT4_I(inode)->jinode) {
979 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
980 					       EXT4_I(inode)->jinode);
981 		jbd2_free_inode(EXT4_I(inode)->jinode);
982 		EXT4_I(inode)->jinode = NULL;
983 	}
984 }
985 
986 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
987 					u64 ino, u32 generation)
988 {
989 	struct inode *inode;
990 
991 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
992 		return ERR_PTR(-ESTALE);
993 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
994 		return ERR_PTR(-ESTALE);
995 
996 	/* iget isn't really right if the inode is currently unallocated!!
997 	 *
998 	 * ext4_read_inode will return a bad_inode if the inode had been
999 	 * deleted, so we should be safe.
1000 	 *
1001 	 * Currently we don't know the generation for parent directory, so
1002 	 * a generation of 0 means "accept any"
1003 	 */
1004 	inode = ext4_iget(sb, ino);
1005 	if (IS_ERR(inode))
1006 		return ERR_CAST(inode);
1007 	if (generation && inode->i_generation != generation) {
1008 		iput(inode);
1009 		return ERR_PTR(-ESTALE);
1010 	}
1011 
1012 	return inode;
1013 }
1014 
1015 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1016 					int fh_len, int fh_type)
1017 {
1018 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1019 				    ext4_nfs_get_inode);
1020 }
1021 
1022 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1023 					int fh_len, int fh_type)
1024 {
1025 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1026 				    ext4_nfs_get_inode);
1027 }
1028 
1029 /*
1030  * Try to release metadata pages (indirect blocks, directories) which are
1031  * mapped via the block device.  Since these pages could have journal heads
1032  * which would prevent try_to_free_buffers() from freeing them, we must use
1033  * jbd2 layer's try_to_free_buffers() function to release them.
1034  */
1035 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1036 				 gfp_t wait)
1037 {
1038 	journal_t *journal = EXT4_SB(sb)->s_journal;
1039 
1040 	WARN_ON(PageChecked(page));
1041 	if (!page_has_buffers(page))
1042 		return 0;
1043 	if (journal)
1044 		return jbd2_journal_try_to_free_buffers(journal, page,
1045 							wait & ~__GFP_WAIT);
1046 	return try_to_free_buffers(page);
1047 }
1048 
1049 #ifdef CONFIG_QUOTA
1050 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1051 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1052 
1053 static int ext4_write_dquot(struct dquot *dquot);
1054 static int ext4_acquire_dquot(struct dquot *dquot);
1055 static int ext4_release_dquot(struct dquot *dquot);
1056 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1057 static int ext4_write_info(struct super_block *sb, int type);
1058 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1059 			 struct path *path);
1060 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1061 				 int format_id);
1062 static int ext4_quota_off(struct super_block *sb, int type);
1063 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1064 static int ext4_quota_on_mount(struct super_block *sb, int type);
1065 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1066 			       size_t len, loff_t off);
1067 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1068 				const char *data, size_t len, loff_t off);
1069 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1070 			     unsigned int flags);
1071 static int ext4_enable_quotas(struct super_block *sb);
1072 
1073 static const struct dquot_operations ext4_quota_operations = {
1074 	.get_reserved_space = ext4_get_reserved_space,
1075 	.write_dquot	= ext4_write_dquot,
1076 	.acquire_dquot	= ext4_acquire_dquot,
1077 	.release_dquot	= ext4_release_dquot,
1078 	.mark_dirty	= ext4_mark_dquot_dirty,
1079 	.write_info	= ext4_write_info,
1080 	.alloc_dquot	= dquot_alloc,
1081 	.destroy_dquot	= dquot_destroy,
1082 };
1083 
1084 static const struct quotactl_ops ext4_qctl_operations = {
1085 	.quota_on	= ext4_quota_on,
1086 	.quota_off	= ext4_quota_off,
1087 	.quota_sync	= dquot_quota_sync,
1088 	.get_info	= dquot_get_dqinfo,
1089 	.set_info	= dquot_set_dqinfo,
1090 	.get_dqblk	= dquot_get_dqblk,
1091 	.set_dqblk	= dquot_set_dqblk
1092 };
1093 
1094 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1095 	.quota_on_meta	= ext4_quota_on_sysfile,
1096 	.quota_off	= ext4_quota_off_sysfile,
1097 	.quota_sync	= dquot_quota_sync,
1098 	.get_info	= dquot_get_dqinfo,
1099 	.set_info	= dquot_set_dqinfo,
1100 	.get_dqblk	= dquot_get_dqblk,
1101 	.set_dqblk	= dquot_set_dqblk
1102 };
1103 #endif
1104 
1105 static const struct super_operations ext4_sops = {
1106 	.alloc_inode	= ext4_alloc_inode,
1107 	.destroy_inode	= ext4_destroy_inode,
1108 	.write_inode	= ext4_write_inode,
1109 	.dirty_inode	= ext4_dirty_inode,
1110 	.drop_inode	= ext4_drop_inode,
1111 	.evict_inode	= ext4_evict_inode,
1112 	.put_super	= ext4_put_super,
1113 	.sync_fs	= ext4_sync_fs,
1114 	.freeze_fs	= ext4_freeze,
1115 	.unfreeze_fs	= ext4_unfreeze,
1116 	.statfs		= ext4_statfs,
1117 	.remount_fs	= ext4_remount,
1118 	.show_options	= ext4_show_options,
1119 #ifdef CONFIG_QUOTA
1120 	.quota_read	= ext4_quota_read,
1121 	.quota_write	= ext4_quota_write,
1122 #endif
1123 	.bdev_try_to_free_page = bdev_try_to_free_page,
1124 };
1125 
1126 static const struct super_operations ext4_nojournal_sops = {
1127 	.alloc_inode	= ext4_alloc_inode,
1128 	.destroy_inode	= ext4_destroy_inode,
1129 	.write_inode	= ext4_write_inode,
1130 	.dirty_inode	= ext4_dirty_inode,
1131 	.drop_inode	= ext4_drop_inode,
1132 	.evict_inode	= ext4_evict_inode,
1133 	.sync_fs	= ext4_sync_fs_nojournal,
1134 	.put_super	= ext4_put_super,
1135 	.statfs		= ext4_statfs,
1136 	.remount_fs	= ext4_remount,
1137 	.show_options	= ext4_show_options,
1138 #ifdef CONFIG_QUOTA
1139 	.quota_read	= ext4_quota_read,
1140 	.quota_write	= ext4_quota_write,
1141 #endif
1142 	.bdev_try_to_free_page = bdev_try_to_free_page,
1143 };
1144 
1145 static const struct export_operations ext4_export_ops = {
1146 	.fh_to_dentry = ext4_fh_to_dentry,
1147 	.fh_to_parent = ext4_fh_to_parent,
1148 	.get_parent = ext4_get_parent,
1149 };
1150 
1151 enum {
1152 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1153 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1154 	Opt_nouid32, Opt_debug, Opt_removed,
1155 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1156 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1157 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1158 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1159 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1160 	Opt_data_err_abort, Opt_data_err_ignore,
1161 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1162 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1163 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1164 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1165 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1166 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1167 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1168 	Opt_dioread_nolock, Opt_dioread_lock,
1169 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1170 	Opt_max_dir_size_kb,
1171 };
1172 
1173 static const match_table_t tokens = {
1174 	{Opt_bsd_df, "bsddf"},
1175 	{Opt_minix_df, "minixdf"},
1176 	{Opt_grpid, "grpid"},
1177 	{Opt_grpid, "bsdgroups"},
1178 	{Opt_nogrpid, "nogrpid"},
1179 	{Opt_nogrpid, "sysvgroups"},
1180 	{Opt_resgid, "resgid=%u"},
1181 	{Opt_resuid, "resuid=%u"},
1182 	{Opt_sb, "sb=%u"},
1183 	{Opt_err_cont, "errors=continue"},
1184 	{Opt_err_panic, "errors=panic"},
1185 	{Opt_err_ro, "errors=remount-ro"},
1186 	{Opt_nouid32, "nouid32"},
1187 	{Opt_debug, "debug"},
1188 	{Opt_removed, "oldalloc"},
1189 	{Opt_removed, "orlov"},
1190 	{Opt_user_xattr, "user_xattr"},
1191 	{Opt_nouser_xattr, "nouser_xattr"},
1192 	{Opt_acl, "acl"},
1193 	{Opt_noacl, "noacl"},
1194 	{Opt_noload, "norecovery"},
1195 	{Opt_noload, "noload"},
1196 	{Opt_removed, "nobh"},
1197 	{Opt_removed, "bh"},
1198 	{Opt_commit, "commit=%u"},
1199 	{Opt_min_batch_time, "min_batch_time=%u"},
1200 	{Opt_max_batch_time, "max_batch_time=%u"},
1201 	{Opt_journal_dev, "journal_dev=%u"},
1202 	{Opt_journal_path, "journal_path=%s"},
1203 	{Opt_journal_checksum, "journal_checksum"},
1204 	{Opt_journal_async_commit, "journal_async_commit"},
1205 	{Opt_abort, "abort"},
1206 	{Opt_data_journal, "data=journal"},
1207 	{Opt_data_ordered, "data=ordered"},
1208 	{Opt_data_writeback, "data=writeback"},
1209 	{Opt_data_err_abort, "data_err=abort"},
1210 	{Opt_data_err_ignore, "data_err=ignore"},
1211 	{Opt_offusrjquota, "usrjquota="},
1212 	{Opt_usrjquota, "usrjquota=%s"},
1213 	{Opt_offgrpjquota, "grpjquota="},
1214 	{Opt_grpjquota, "grpjquota=%s"},
1215 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1216 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1217 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1218 	{Opt_grpquota, "grpquota"},
1219 	{Opt_noquota, "noquota"},
1220 	{Opt_quota, "quota"},
1221 	{Opt_usrquota, "usrquota"},
1222 	{Opt_barrier, "barrier=%u"},
1223 	{Opt_barrier, "barrier"},
1224 	{Opt_nobarrier, "nobarrier"},
1225 	{Opt_i_version, "i_version"},
1226 	{Opt_stripe, "stripe=%u"},
1227 	{Opt_delalloc, "delalloc"},
1228 	{Opt_nodelalloc, "nodelalloc"},
1229 	{Opt_removed, "mblk_io_submit"},
1230 	{Opt_removed, "nomblk_io_submit"},
1231 	{Opt_block_validity, "block_validity"},
1232 	{Opt_noblock_validity, "noblock_validity"},
1233 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1234 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1235 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1236 	{Opt_auto_da_alloc, "auto_da_alloc"},
1237 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1238 	{Opt_dioread_nolock, "dioread_nolock"},
1239 	{Opt_dioread_lock, "dioread_lock"},
1240 	{Opt_discard, "discard"},
1241 	{Opt_nodiscard, "nodiscard"},
1242 	{Opt_init_itable, "init_itable=%u"},
1243 	{Opt_init_itable, "init_itable"},
1244 	{Opt_noinit_itable, "noinit_itable"},
1245 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1246 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1247 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1248 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1249 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1250 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1251 	{Opt_err, NULL},
1252 };
1253 
1254 static ext4_fsblk_t get_sb_block(void **data)
1255 {
1256 	ext4_fsblk_t	sb_block;
1257 	char		*options = (char *) *data;
1258 
1259 	if (!options || strncmp(options, "sb=", 3) != 0)
1260 		return 1;	/* Default location */
1261 
1262 	options += 3;
1263 	/* TODO: use simple_strtoll with >32bit ext4 */
1264 	sb_block = simple_strtoul(options, &options, 0);
1265 	if (*options && *options != ',') {
1266 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1267 		       (char *) *data);
1268 		return 1;
1269 	}
1270 	if (*options == ',')
1271 		options++;
1272 	*data = (void *) options;
1273 
1274 	return sb_block;
1275 }
1276 
1277 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1278 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1279 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1280 
1281 #ifdef CONFIG_QUOTA
1282 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1283 {
1284 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1285 	char *qname;
1286 	int ret = -1;
1287 
1288 	if (sb_any_quota_loaded(sb) &&
1289 		!sbi->s_qf_names[qtype]) {
1290 		ext4_msg(sb, KERN_ERR,
1291 			"Cannot change journaled "
1292 			"quota options when quota turned on");
1293 		return -1;
1294 	}
1295 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1296 		ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1297 			 "when QUOTA feature is enabled");
1298 		return -1;
1299 	}
1300 	qname = match_strdup(args);
1301 	if (!qname) {
1302 		ext4_msg(sb, KERN_ERR,
1303 			"Not enough memory for storing quotafile name");
1304 		return -1;
1305 	}
1306 	if (sbi->s_qf_names[qtype]) {
1307 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1308 			ret = 1;
1309 		else
1310 			ext4_msg(sb, KERN_ERR,
1311 				 "%s quota file already specified",
1312 				 QTYPE2NAME(qtype));
1313 		goto errout;
1314 	}
1315 	if (strchr(qname, '/')) {
1316 		ext4_msg(sb, KERN_ERR,
1317 			"quotafile must be on filesystem root");
1318 		goto errout;
1319 	}
1320 	sbi->s_qf_names[qtype] = qname;
1321 	set_opt(sb, QUOTA);
1322 	return 1;
1323 errout:
1324 	kfree(qname);
1325 	return ret;
1326 }
1327 
1328 static int clear_qf_name(struct super_block *sb, int qtype)
1329 {
1330 
1331 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1332 
1333 	if (sb_any_quota_loaded(sb) &&
1334 		sbi->s_qf_names[qtype]) {
1335 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1336 			" when quota turned on");
1337 		return -1;
1338 	}
1339 	kfree(sbi->s_qf_names[qtype]);
1340 	sbi->s_qf_names[qtype] = NULL;
1341 	return 1;
1342 }
1343 #endif
1344 
1345 #define MOPT_SET	0x0001
1346 #define MOPT_CLEAR	0x0002
1347 #define MOPT_NOSUPPORT	0x0004
1348 #define MOPT_EXPLICIT	0x0008
1349 #define MOPT_CLEAR_ERR	0x0010
1350 #define MOPT_GTE0	0x0020
1351 #ifdef CONFIG_QUOTA
1352 #define MOPT_Q		0
1353 #define MOPT_QFMT	0x0040
1354 #else
1355 #define MOPT_Q		MOPT_NOSUPPORT
1356 #define MOPT_QFMT	MOPT_NOSUPPORT
1357 #endif
1358 #define MOPT_DATAJ	0x0080
1359 #define MOPT_NO_EXT2	0x0100
1360 #define MOPT_NO_EXT3	0x0200
1361 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1362 #define MOPT_STRING	0x0400
1363 
1364 static const struct mount_opts {
1365 	int	token;
1366 	int	mount_opt;
1367 	int	flags;
1368 } ext4_mount_opts[] = {
1369 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1370 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1371 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1372 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1373 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1374 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1375 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1376 	 MOPT_EXT4_ONLY | MOPT_SET},
1377 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1378 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1379 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1380 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1381 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1382 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1383 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1384 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1385 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1386 	 MOPT_EXT4_ONLY | MOPT_SET},
1387 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1388 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1389 	 MOPT_EXT4_ONLY | MOPT_SET},
1390 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1391 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1392 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1393 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1394 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1395 	 MOPT_NO_EXT2 | MOPT_SET},
1396 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1397 	 MOPT_NO_EXT2 | MOPT_CLEAR},
1398 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1399 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1400 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1401 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1402 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1403 	{Opt_commit, 0, MOPT_GTE0},
1404 	{Opt_max_batch_time, 0, MOPT_GTE0},
1405 	{Opt_min_batch_time, 0, MOPT_GTE0},
1406 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1407 	{Opt_init_itable, 0, MOPT_GTE0},
1408 	{Opt_stripe, 0, MOPT_GTE0},
1409 	{Opt_resuid, 0, MOPT_GTE0},
1410 	{Opt_resgid, 0, MOPT_GTE0},
1411 	{Opt_journal_dev, 0, MOPT_GTE0},
1412 	{Opt_journal_path, 0, MOPT_STRING},
1413 	{Opt_journal_ioprio, 0, MOPT_GTE0},
1414 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1415 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1416 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1417 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1418 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1419 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1420 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1421 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1422 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1423 #else
1424 	{Opt_acl, 0, MOPT_NOSUPPORT},
1425 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1426 #endif
1427 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1428 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1429 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1430 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1431 							MOPT_SET | MOPT_Q},
1432 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1433 							MOPT_SET | MOPT_Q},
1434 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1435 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1436 	{Opt_usrjquota, 0, MOPT_Q},
1437 	{Opt_grpjquota, 0, MOPT_Q},
1438 	{Opt_offusrjquota, 0, MOPT_Q},
1439 	{Opt_offgrpjquota, 0, MOPT_Q},
1440 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1441 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1442 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1443 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1444 	{Opt_err, 0, 0}
1445 };
1446 
1447 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1448 			    substring_t *args, unsigned long *journal_devnum,
1449 			    unsigned int *journal_ioprio, int is_remount)
1450 {
1451 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1452 	const struct mount_opts *m;
1453 	kuid_t uid;
1454 	kgid_t gid;
1455 	int arg = 0;
1456 
1457 #ifdef CONFIG_QUOTA
1458 	if (token == Opt_usrjquota)
1459 		return set_qf_name(sb, USRQUOTA, &args[0]);
1460 	else if (token == Opt_grpjquota)
1461 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1462 	else if (token == Opt_offusrjquota)
1463 		return clear_qf_name(sb, USRQUOTA);
1464 	else if (token == Opt_offgrpjquota)
1465 		return clear_qf_name(sb, GRPQUOTA);
1466 #endif
1467 	switch (token) {
1468 	case Opt_noacl:
1469 	case Opt_nouser_xattr:
1470 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1471 		break;
1472 	case Opt_sb:
1473 		return 1;	/* handled by get_sb_block() */
1474 	case Opt_removed:
1475 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1476 		return 1;
1477 	case Opt_abort:
1478 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1479 		return 1;
1480 	case Opt_i_version:
1481 		sb->s_flags |= MS_I_VERSION;
1482 		return 1;
1483 	}
1484 
1485 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1486 		if (token == m->token)
1487 			break;
1488 
1489 	if (m->token == Opt_err) {
1490 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1491 			 "or missing value", opt);
1492 		return -1;
1493 	}
1494 
1495 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1496 		ext4_msg(sb, KERN_ERR,
1497 			 "Mount option \"%s\" incompatible with ext2", opt);
1498 		return -1;
1499 	}
1500 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1501 		ext4_msg(sb, KERN_ERR,
1502 			 "Mount option \"%s\" incompatible with ext3", opt);
1503 		return -1;
1504 	}
1505 
1506 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1507 		return -1;
1508 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1509 		return -1;
1510 	if (m->flags & MOPT_EXPLICIT)
1511 		set_opt2(sb, EXPLICIT_DELALLOC);
1512 	if (m->flags & MOPT_CLEAR_ERR)
1513 		clear_opt(sb, ERRORS_MASK);
1514 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1515 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1516 			 "options when quota turned on");
1517 		return -1;
1518 	}
1519 
1520 	if (m->flags & MOPT_NOSUPPORT) {
1521 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1522 	} else if (token == Opt_commit) {
1523 		if (arg == 0)
1524 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1525 		sbi->s_commit_interval = HZ * arg;
1526 	} else if (token == Opt_max_batch_time) {
1527 		if (arg == 0)
1528 			arg = EXT4_DEF_MAX_BATCH_TIME;
1529 		sbi->s_max_batch_time = arg;
1530 	} else if (token == Opt_min_batch_time) {
1531 		sbi->s_min_batch_time = arg;
1532 	} else if (token == Opt_inode_readahead_blks) {
1533 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1534 			ext4_msg(sb, KERN_ERR,
1535 				 "EXT4-fs: inode_readahead_blks must be "
1536 				 "0 or a power of 2 smaller than 2^31");
1537 			return -1;
1538 		}
1539 		sbi->s_inode_readahead_blks = arg;
1540 	} else if (token == Opt_init_itable) {
1541 		set_opt(sb, INIT_INODE_TABLE);
1542 		if (!args->from)
1543 			arg = EXT4_DEF_LI_WAIT_MULT;
1544 		sbi->s_li_wait_mult = arg;
1545 	} else if (token == Opt_max_dir_size_kb) {
1546 		sbi->s_max_dir_size_kb = arg;
1547 	} else if (token == Opt_stripe) {
1548 		sbi->s_stripe = arg;
1549 	} else if (token == Opt_resuid) {
1550 		uid = make_kuid(current_user_ns(), arg);
1551 		if (!uid_valid(uid)) {
1552 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1553 			return -1;
1554 		}
1555 		sbi->s_resuid = uid;
1556 	} else if (token == Opt_resgid) {
1557 		gid = make_kgid(current_user_ns(), arg);
1558 		if (!gid_valid(gid)) {
1559 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1560 			return -1;
1561 		}
1562 		sbi->s_resgid = gid;
1563 	} else if (token == Opt_journal_dev) {
1564 		if (is_remount) {
1565 			ext4_msg(sb, KERN_ERR,
1566 				 "Cannot specify journal on remount");
1567 			return -1;
1568 		}
1569 		*journal_devnum = arg;
1570 	} else if (token == Opt_journal_path) {
1571 		char *journal_path;
1572 		struct inode *journal_inode;
1573 		struct path path;
1574 		int error;
1575 
1576 		if (is_remount) {
1577 			ext4_msg(sb, KERN_ERR,
1578 				 "Cannot specify journal on remount");
1579 			return -1;
1580 		}
1581 		journal_path = match_strdup(&args[0]);
1582 		if (!journal_path) {
1583 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1584 				"journal device string");
1585 			return -1;
1586 		}
1587 
1588 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1589 		if (error) {
1590 			ext4_msg(sb, KERN_ERR, "error: could not find "
1591 				"journal device path: error %d", error);
1592 			kfree(journal_path);
1593 			return -1;
1594 		}
1595 
1596 		journal_inode = path.dentry->d_inode;
1597 		if (!S_ISBLK(journal_inode->i_mode)) {
1598 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1599 				"is not a block device", journal_path);
1600 			path_put(&path);
1601 			kfree(journal_path);
1602 			return -1;
1603 		}
1604 
1605 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1606 		path_put(&path);
1607 		kfree(journal_path);
1608 	} else if (token == Opt_journal_ioprio) {
1609 		if (arg > 7) {
1610 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1611 				 " (must be 0-7)");
1612 			return -1;
1613 		}
1614 		*journal_ioprio =
1615 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1616 	} else if (m->flags & MOPT_DATAJ) {
1617 		if (is_remount) {
1618 			if (!sbi->s_journal)
1619 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1620 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1621 				ext4_msg(sb, KERN_ERR,
1622 					 "Cannot change data mode on remount");
1623 				return -1;
1624 			}
1625 		} else {
1626 			clear_opt(sb, DATA_FLAGS);
1627 			sbi->s_mount_opt |= m->mount_opt;
1628 		}
1629 #ifdef CONFIG_QUOTA
1630 	} else if (m->flags & MOPT_QFMT) {
1631 		if (sb_any_quota_loaded(sb) &&
1632 		    sbi->s_jquota_fmt != m->mount_opt) {
1633 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1634 				 "quota options when quota turned on");
1635 			return -1;
1636 		}
1637 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1638 					       EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1639 			ext4_msg(sb, KERN_ERR,
1640 				 "Cannot set journaled quota options "
1641 				 "when QUOTA feature is enabled");
1642 			return -1;
1643 		}
1644 		sbi->s_jquota_fmt = m->mount_opt;
1645 #endif
1646 	} else {
1647 		if (!args->from)
1648 			arg = 1;
1649 		if (m->flags & MOPT_CLEAR)
1650 			arg = !arg;
1651 		else if (unlikely(!(m->flags & MOPT_SET))) {
1652 			ext4_msg(sb, KERN_WARNING,
1653 				 "buggy handling of option %s", opt);
1654 			WARN_ON(1);
1655 			return -1;
1656 		}
1657 		if (arg != 0)
1658 			sbi->s_mount_opt |= m->mount_opt;
1659 		else
1660 			sbi->s_mount_opt &= ~m->mount_opt;
1661 	}
1662 	return 1;
1663 }
1664 
1665 static int parse_options(char *options, struct super_block *sb,
1666 			 unsigned long *journal_devnum,
1667 			 unsigned int *journal_ioprio,
1668 			 int is_remount)
1669 {
1670 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1671 	char *p;
1672 	substring_t args[MAX_OPT_ARGS];
1673 	int token;
1674 
1675 	if (!options)
1676 		return 1;
1677 
1678 	while ((p = strsep(&options, ",")) != NULL) {
1679 		if (!*p)
1680 			continue;
1681 		/*
1682 		 * Initialize args struct so we know whether arg was
1683 		 * found; some options take optional arguments.
1684 		 */
1685 		args[0].to = args[0].from = NULL;
1686 		token = match_token(p, tokens, args);
1687 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1688 				     journal_ioprio, is_remount) < 0)
1689 			return 0;
1690 	}
1691 #ifdef CONFIG_QUOTA
1692 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1693 	    (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1694 		ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1695 			 "feature is enabled");
1696 		return 0;
1697 	}
1698 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1699 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1700 			clear_opt(sb, USRQUOTA);
1701 
1702 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1703 			clear_opt(sb, GRPQUOTA);
1704 
1705 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1706 			ext4_msg(sb, KERN_ERR, "old and new quota "
1707 					"format mixing");
1708 			return 0;
1709 		}
1710 
1711 		if (!sbi->s_jquota_fmt) {
1712 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1713 					"not specified");
1714 			return 0;
1715 		}
1716 	} else {
1717 		if (sbi->s_jquota_fmt) {
1718 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1719 					"specified with no journaling "
1720 					"enabled");
1721 			return 0;
1722 		}
1723 	}
1724 #endif
1725 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1726 		int blocksize =
1727 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1728 
1729 		if (blocksize < PAGE_CACHE_SIZE) {
1730 			ext4_msg(sb, KERN_ERR, "can't mount with "
1731 				 "dioread_nolock if block size != PAGE_SIZE");
1732 			return 0;
1733 		}
1734 	}
1735 	return 1;
1736 }
1737 
1738 static inline void ext4_show_quota_options(struct seq_file *seq,
1739 					   struct super_block *sb)
1740 {
1741 #if defined(CONFIG_QUOTA)
1742 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1743 
1744 	if (sbi->s_jquota_fmt) {
1745 		char *fmtname = "";
1746 
1747 		switch (sbi->s_jquota_fmt) {
1748 		case QFMT_VFS_OLD:
1749 			fmtname = "vfsold";
1750 			break;
1751 		case QFMT_VFS_V0:
1752 			fmtname = "vfsv0";
1753 			break;
1754 		case QFMT_VFS_V1:
1755 			fmtname = "vfsv1";
1756 			break;
1757 		}
1758 		seq_printf(seq, ",jqfmt=%s", fmtname);
1759 	}
1760 
1761 	if (sbi->s_qf_names[USRQUOTA])
1762 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1763 
1764 	if (sbi->s_qf_names[GRPQUOTA])
1765 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1766 #endif
1767 }
1768 
1769 static const char *token2str(int token)
1770 {
1771 	const struct match_token *t;
1772 
1773 	for (t = tokens; t->token != Opt_err; t++)
1774 		if (t->token == token && !strchr(t->pattern, '='))
1775 			break;
1776 	return t->pattern;
1777 }
1778 
1779 /*
1780  * Show an option if
1781  *  - it's set to a non-default value OR
1782  *  - if the per-sb default is different from the global default
1783  */
1784 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1785 			      int nodefs)
1786 {
1787 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1788 	struct ext4_super_block *es = sbi->s_es;
1789 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1790 	const struct mount_opts *m;
1791 	char sep = nodefs ? '\n' : ',';
1792 
1793 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1794 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1795 
1796 	if (sbi->s_sb_block != 1)
1797 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1798 
1799 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1800 		int want_set = m->flags & MOPT_SET;
1801 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1802 		    (m->flags & MOPT_CLEAR_ERR))
1803 			continue;
1804 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1805 			continue; /* skip if same as the default */
1806 		if ((want_set &&
1807 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1808 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1809 			continue; /* select Opt_noFoo vs Opt_Foo */
1810 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1811 	}
1812 
1813 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1814 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1815 		SEQ_OPTS_PRINT("resuid=%u",
1816 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1817 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1818 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1819 		SEQ_OPTS_PRINT("resgid=%u",
1820 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1821 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1822 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1823 		SEQ_OPTS_PUTS("errors=remount-ro");
1824 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1825 		SEQ_OPTS_PUTS("errors=continue");
1826 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1827 		SEQ_OPTS_PUTS("errors=panic");
1828 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1829 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1830 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1831 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1832 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1833 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1834 	if (sb->s_flags & MS_I_VERSION)
1835 		SEQ_OPTS_PUTS("i_version");
1836 	if (nodefs || sbi->s_stripe)
1837 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1838 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1839 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1840 			SEQ_OPTS_PUTS("data=journal");
1841 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1842 			SEQ_OPTS_PUTS("data=ordered");
1843 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1844 			SEQ_OPTS_PUTS("data=writeback");
1845 	}
1846 	if (nodefs ||
1847 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1848 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1849 			       sbi->s_inode_readahead_blks);
1850 
1851 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1852 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1853 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1854 	if (nodefs || sbi->s_max_dir_size_kb)
1855 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1856 
1857 	ext4_show_quota_options(seq, sb);
1858 	return 0;
1859 }
1860 
1861 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1862 {
1863 	return _ext4_show_options(seq, root->d_sb, 0);
1864 }
1865 
1866 static int options_seq_show(struct seq_file *seq, void *offset)
1867 {
1868 	struct super_block *sb = seq->private;
1869 	int rc;
1870 
1871 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1872 	rc = _ext4_show_options(seq, sb, 1);
1873 	seq_puts(seq, "\n");
1874 	return rc;
1875 }
1876 
1877 static int options_open_fs(struct inode *inode, struct file *file)
1878 {
1879 	return single_open(file, options_seq_show, PDE_DATA(inode));
1880 }
1881 
1882 static const struct file_operations ext4_seq_options_fops = {
1883 	.owner = THIS_MODULE,
1884 	.open = options_open_fs,
1885 	.read = seq_read,
1886 	.llseek = seq_lseek,
1887 	.release = single_release,
1888 };
1889 
1890 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1891 			    int read_only)
1892 {
1893 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1894 	int res = 0;
1895 
1896 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1897 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1898 			 "forcing read-only mode");
1899 		res = MS_RDONLY;
1900 	}
1901 	if (read_only)
1902 		goto done;
1903 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1904 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1905 			 "running e2fsck is recommended");
1906 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1907 		ext4_msg(sb, KERN_WARNING,
1908 			 "warning: mounting fs with errors, "
1909 			 "running e2fsck is recommended");
1910 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1911 		 le16_to_cpu(es->s_mnt_count) >=
1912 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1913 		ext4_msg(sb, KERN_WARNING,
1914 			 "warning: maximal mount count reached, "
1915 			 "running e2fsck is recommended");
1916 	else if (le32_to_cpu(es->s_checkinterval) &&
1917 		(le32_to_cpu(es->s_lastcheck) +
1918 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1919 		ext4_msg(sb, KERN_WARNING,
1920 			 "warning: checktime reached, "
1921 			 "running e2fsck is recommended");
1922 	if (!sbi->s_journal)
1923 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1924 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1925 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1926 	le16_add_cpu(&es->s_mnt_count, 1);
1927 	es->s_mtime = cpu_to_le32(get_seconds());
1928 	ext4_update_dynamic_rev(sb);
1929 	if (sbi->s_journal)
1930 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1931 
1932 	ext4_commit_super(sb, 1);
1933 done:
1934 	if (test_opt(sb, DEBUG))
1935 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1936 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1937 			sb->s_blocksize,
1938 			sbi->s_groups_count,
1939 			EXT4_BLOCKS_PER_GROUP(sb),
1940 			EXT4_INODES_PER_GROUP(sb),
1941 			sbi->s_mount_opt, sbi->s_mount_opt2);
1942 
1943 	cleancache_init_fs(sb);
1944 	return res;
1945 }
1946 
1947 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1948 {
1949 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1950 	struct flex_groups *new_groups;
1951 	int size;
1952 
1953 	if (!sbi->s_log_groups_per_flex)
1954 		return 0;
1955 
1956 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
1957 	if (size <= sbi->s_flex_groups_allocated)
1958 		return 0;
1959 
1960 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1961 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1962 	if (!new_groups) {
1963 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1964 			 size / (int) sizeof(struct flex_groups));
1965 		return -ENOMEM;
1966 	}
1967 
1968 	if (sbi->s_flex_groups) {
1969 		memcpy(new_groups, sbi->s_flex_groups,
1970 		       (sbi->s_flex_groups_allocated *
1971 			sizeof(struct flex_groups)));
1972 		ext4_kvfree(sbi->s_flex_groups);
1973 	}
1974 	sbi->s_flex_groups = new_groups;
1975 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1976 	return 0;
1977 }
1978 
1979 static int ext4_fill_flex_info(struct super_block *sb)
1980 {
1981 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1982 	struct ext4_group_desc *gdp = NULL;
1983 	ext4_group_t flex_group;
1984 	int i, err;
1985 
1986 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1987 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1988 		sbi->s_log_groups_per_flex = 0;
1989 		return 1;
1990 	}
1991 
1992 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1993 	if (err)
1994 		goto failed;
1995 
1996 	for (i = 0; i < sbi->s_groups_count; i++) {
1997 		gdp = ext4_get_group_desc(sb, i, NULL);
1998 
1999 		flex_group = ext4_flex_group(sbi, i);
2000 		atomic_add(ext4_free_inodes_count(sb, gdp),
2001 			   &sbi->s_flex_groups[flex_group].free_inodes);
2002 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2003 			     &sbi->s_flex_groups[flex_group].free_clusters);
2004 		atomic_add(ext4_used_dirs_count(sb, gdp),
2005 			   &sbi->s_flex_groups[flex_group].used_dirs);
2006 	}
2007 
2008 	return 1;
2009 failed:
2010 	return 0;
2011 }
2012 
2013 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2014 				   struct ext4_group_desc *gdp)
2015 {
2016 	int offset;
2017 	__u16 crc = 0;
2018 	__le32 le_group = cpu_to_le32(block_group);
2019 
2020 	if ((sbi->s_es->s_feature_ro_compat &
2021 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
2022 		/* Use new metadata_csum algorithm */
2023 		__le16 save_csum;
2024 		__u32 csum32;
2025 
2026 		save_csum = gdp->bg_checksum;
2027 		gdp->bg_checksum = 0;
2028 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2029 				     sizeof(le_group));
2030 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2031 				     sbi->s_desc_size);
2032 		gdp->bg_checksum = save_csum;
2033 
2034 		crc = csum32 & 0xFFFF;
2035 		goto out;
2036 	}
2037 
2038 	/* old crc16 code */
2039 	offset = offsetof(struct ext4_group_desc, bg_checksum);
2040 
2041 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2042 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2043 	crc = crc16(crc, (__u8 *)gdp, offset);
2044 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2045 	/* for checksum of struct ext4_group_desc do the rest...*/
2046 	if ((sbi->s_es->s_feature_incompat &
2047 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2048 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2049 		crc = crc16(crc, (__u8 *)gdp + offset,
2050 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2051 				offset);
2052 
2053 out:
2054 	return cpu_to_le16(crc);
2055 }
2056 
2057 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2058 				struct ext4_group_desc *gdp)
2059 {
2060 	if (ext4_has_group_desc_csum(sb) &&
2061 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2062 						      block_group, gdp)))
2063 		return 0;
2064 
2065 	return 1;
2066 }
2067 
2068 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2069 			      struct ext4_group_desc *gdp)
2070 {
2071 	if (!ext4_has_group_desc_csum(sb))
2072 		return;
2073 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2074 }
2075 
2076 /* Called at mount-time, super-block is locked */
2077 static int ext4_check_descriptors(struct super_block *sb,
2078 				  ext4_group_t *first_not_zeroed)
2079 {
2080 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2081 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2082 	ext4_fsblk_t last_block;
2083 	ext4_fsblk_t block_bitmap;
2084 	ext4_fsblk_t inode_bitmap;
2085 	ext4_fsblk_t inode_table;
2086 	int flexbg_flag = 0;
2087 	ext4_group_t i, grp = sbi->s_groups_count;
2088 
2089 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2090 		flexbg_flag = 1;
2091 
2092 	ext4_debug("Checking group descriptors");
2093 
2094 	for (i = 0; i < sbi->s_groups_count; i++) {
2095 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2096 
2097 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2098 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2099 		else
2100 			last_block = first_block +
2101 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2102 
2103 		if ((grp == sbi->s_groups_count) &&
2104 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2105 			grp = i;
2106 
2107 		block_bitmap = ext4_block_bitmap(sb, gdp);
2108 		if (block_bitmap < first_block || block_bitmap > last_block) {
2109 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2110 			       "Block bitmap for group %u not in group "
2111 			       "(block %llu)!", i, block_bitmap);
2112 			return 0;
2113 		}
2114 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2115 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2116 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2117 			       "Inode bitmap for group %u not in group "
2118 			       "(block %llu)!", i, inode_bitmap);
2119 			return 0;
2120 		}
2121 		inode_table = ext4_inode_table(sb, gdp);
2122 		if (inode_table < first_block ||
2123 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2124 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2125 			       "Inode table for group %u not in group "
2126 			       "(block %llu)!", i, inode_table);
2127 			return 0;
2128 		}
2129 		ext4_lock_group(sb, i);
2130 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2131 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2132 				 "Checksum for group %u failed (%u!=%u)",
2133 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2134 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2135 			if (!(sb->s_flags & MS_RDONLY)) {
2136 				ext4_unlock_group(sb, i);
2137 				return 0;
2138 			}
2139 		}
2140 		ext4_unlock_group(sb, i);
2141 		if (!flexbg_flag)
2142 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2143 	}
2144 	if (NULL != first_not_zeroed)
2145 		*first_not_zeroed = grp;
2146 
2147 	ext4_free_blocks_count_set(sbi->s_es,
2148 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2149 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2150 	return 1;
2151 }
2152 
2153 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2154  * the superblock) which were deleted from all directories, but held open by
2155  * a process at the time of a crash.  We walk the list and try to delete these
2156  * inodes at recovery time (only with a read-write filesystem).
2157  *
2158  * In order to keep the orphan inode chain consistent during traversal (in
2159  * case of crash during recovery), we link each inode into the superblock
2160  * orphan list_head and handle it the same way as an inode deletion during
2161  * normal operation (which journals the operations for us).
2162  *
2163  * We only do an iget() and an iput() on each inode, which is very safe if we
2164  * accidentally point at an in-use or already deleted inode.  The worst that
2165  * can happen in this case is that we get a "bit already cleared" message from
2166  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2167  * e2fsck was run on this filesystem, and it must have already done the orphan
2168  * inode cleanup for us, so we can safely abort without any further action.
2169  */
2170 static void ext4_orphan_cleanup(struct super_block *sb,
2171 				struct ext4_super_block *es)
2172 {
2173 	unsigned int s_flags = sb->s_flags;
2174 	int nr_orphans = 0, nr_truncates = 0;
2175 #ifdef CONFIG_QUOTA
2176 	int i;
2177 #endif
2178 	if (!es->s_last_orphan) {
2179 		jbd_debug(4, "no orphan inodes to clean up\n");
2180 		return;
2181 	}
2182 
2183 	if (bdev_read_only(sb->s_bdev)) {
2184 		ext4_msg(sb, KERN_ERR, "write access "
2185 			"unavailable, skipping orphan cleanup");
2186 		return;
2187 	}
2188 
2189 	/* Check if feature set would not allow a r/w mount */
2190 	if (!ext4_feature_set_ok(sb, 0)) {
2191 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2192 			 "unknown ROCOMPAT features");
2193 		return;
2194 	}
2195 
2196 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2197 		/* don't clear list on RO mount w/ errors */
2198 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2199 			jbd_debug(1, "Errors on filesystem, "
2200 				  "clearing orphan list.\n");
2201 			es->s_last_orphan = 0;
2202 		}
2203 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2204 		return;
2205 	}
2206 
2207 	if (s_flags & MS_RDONLY) {
2208 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2209 		sb->s_flags &= ~MS_RDONLY;
2210 	}
2211 #ifdef CONFIG_QUOTA
2212 	/* Needed for iput() to work correctly and not trash data */
2213 	sb->s_flags |= MS_ACTIVE;
2214 	/* Turn on quotas so that they are updated correctly */
2215 	for (i = 0; i < MAXQUOTAS; i++) {
2216 		if (EXT4_SB(sb)->s_qf_names[i]) {
2217 			int ret = ext4_quota_on_mount(sb, i);
2218 			if (ret < 0)
2219 				ext4_msg(sb, KERN_ERR,
2220 					"Cannot turn on journaled "
2221 					"quota: error %d", ret);
2222 		}
2223 	}
2224 #endif
2225 
2226 	while (es->s_last_orphan) {
2227 		struct inode *inode;
2228 
2229 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2230 		if (IS_ERR(inode)) {
2231 			es->s_last_orphan = 0;
2232 			break;
2233 		}
2234 
2235 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2236 		dquot_initialize(inode);
2237 		if (inode->i_nlink) {
2238 			if (test_opt(sb, DEBUG))
2239 				ext4_msg(sb, KERN_DEBUG,
2240 					"%s: truncating inode %lu to %lld bytes",
2241 					__func__, inode->i_ino, inode->i_size);
2242 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2243 				  inode->i_ino, inode->i_size);
2244 			mutex_lock(&inode->i_mutex);
2245 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2246 			ext4_truncate(inode);
2247 			mutex_unlock(&inode->i_mutex);
2248 			nr_truncates++;
2249 		} else {
2250 			if (test_opt(sb, DEBUG))
2251 				ext4_msg(sb, KERN_DEBUG,
2252 					"%s: deleting unreferenced inode %lu",
2253 					__func__, inode->i_ino);
2254 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2255 				  inode->i_ino);
2256 			nr_orphans++;
2257 		}
2258 		iput(inode);  /* The delete magic happens here! */
2259 	}
2260 
2261 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2262 
2263 	if (nr_orphans)
2264 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2265 		       PLURAL(nr_orphans));
2266 	if (nr_truncates)
2267 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2268 		       PLURAL(nr_truncates));
2269 #ifdef CONFIG_QUOTA
2270 	/* Turn quotas off */
2271 	for (i = 0; i < MAXQUOTAS; i++) {
2272 		if (sb_dqopt(sb)->files[i])
2273 			dquot_quota_off(sb, i);
2274 	}
2275 #endif
2276 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2277 }
2278 
2279 /*
2280  * Maximal extent format file size.
2281  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2282  * extent format containers, within a sector_t, and within i_blocks
2283  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2284  * so that won't be a limiting factor.
2285  *
2286  * However there is other limiting factor. We do store extents in the form
2287  * of starting block and length, hence the resulting length of the extent
2288  * covering maximum file size must fit into on-disk format containers as
2289  * well. Given that length is always by 1 unit bigger than max unit (because
2290  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2291  *
2292  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2293  */
2294 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2295 {
2296 	loff_t res;
2297 	loff_t upper_limit = MAX_LFS_FILESIZE;
2298 
2299 	/* small i_blocks in vfs inode? */
2300 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2301 		/*
2302 		 * CONFIG_LBDAF is not enabled implies the inode
2303 		 * i_block represent total blocks in 512 bytes
2304 		 * 32 == size of vfs inode i_blocks * 8
2305 		 */
2306 		upper_limit = (1LL << 32) - 1;
2307 
2308 		/* total blocks in file system block size */
2309 		upper_limit >>= (blkbits - 9);
2310 		upper_limit <<= blkbits;
2311 	}
2312 
2313 	/*
2314 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2315 	 * by one fs block, so ee_len can cover the extent of maximum file
2316 	 * size
2317 	 */
2318 	res = (1LL << 32) - 1;
2319 	res <<= blkbits;
2320 
2321 	/* Sanity check against vm- & vfs- imposed limits */
2322 	if (res > upper_limit)
2323 		res = upper_limit;
2324 
2325 	return res;
2326 }
2327 
2328 /*
2329  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2330  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2331  * We need to be 1 filesystem block less than the 2^48 sector limit.
2332  */
2333 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2334 {
2335 	loff_t res = EXT4_NDIR_BLOCKS;
2336 	int meta_blocks;
2337 	loff_t upper_limit;
2338 	/* This is calculated to be the largest file size for a dense, block
2339 	 * mapped file such that the file's total number of 512-byte sectors,
2340 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2341 	 *
2342 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2343 	 * number of 512-byte sectors of the file.
2344 	 */
2345 
2346 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2347 		/*
2348 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2349 		 * the inode i_block field represents total file blocks in
2350 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2351 		 */
2352 		upper_limit = (1LL << 32) - 1;
2353 
2354 		/* total blocks in file system block size */
2355 		upper_limit >>= (bits - 9);
2356 
2357 	} else {
2358 		/*
2359 		 * We use 48 bit ext4_inode i_blocks
2360 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2361 		 * represent total number of blocks in
2362 		 * file system block size
2363 		 */
2364 		upper_limit = (1LL << 48) - 1;
2365 
2366 	}
2367 
2368 	/* indirect blocks */
2369 	meta_blocks = 1;
2370 	/* double indirect blocks */
2371 	meta_blocks += 1 + (1LL << (bits-2));
2372 	/* tripple indirect blocks */
2373 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2374 
2375 	upper_limit -= meta_blocks;
2376 	upper_limit <<= bits;
2377 
2378 	res += 1LL << (bits-2);
2379 	res += 1LL << (2*(bits-2));
2380 	res += 1LL << (3*(bits-2));
2381 	res <<= bits;
2382 	if (res > upper_limit)
2383 		res = upper_limit;
2384 
2385 	if (res > MAX_LFS_FILESIZE)
2386 		res = MAX_LFS_FILESIZE;
2387 
2388 	return res;
2389 }
2390 
2391 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2392 				   ext4_fsblk_t logical_sb_block, int nr)
2393 {
2394 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2395 	ext4_group_t bg, first_meta_bg;
2396 	int has_super = 0;
2397 
2398 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2399 
2400 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2401 	    nr < first_meta_bg)
2402 		return logical_sb_block + nr + 1;
2403 	bg = sbi->s_desc_per_block * nr;
2404 	if (ext4_bg_has_super(sb, bg))
2405 		has_super = 1;
2406 
2407 	return (has_super + ext4_group_first_block_no(sb, bg));
2408 }
2409 
2410 /**
2411  * ext4_get_stripe_size: Get the stripe size.
2412  * @sbi: In memory super block info
2413  *
2414  * If we have specified it via mount option, then
2415  * use the mount option value. If the value specified at mount time is
2416  * greater than the blocks per group use the super block value.
2417  * If the super block value is greater than blocks per group return 0.
2418  * Allocator needs it be less than blocks per group.
2419  *
2420  */
2421 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2422 {
2423 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2424 	unsigned long stripe_width =
2425 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2426 	int ret;
2427 
2428 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2429 		ret = sbi->s_stripe;
2430 	else if (stripe_width <= sbi->s_blocks_per_group)
2431 		ret = stripe_width;
2432 	else if (stride <= sbi->s_blocks_per_group)
2433 		ret = stride;
2434 	else
2435 		ret = 0;
2436 
2437 	/*
2438 	 * If the stripe width is 1, this makes no sense and
2439 	 * we set it to 0 to turn off stripe handling code.
2440 	 */
2441 	if (ret <= 1)
2442 		ret = 0;
2443 
2444 	return ret;
2445 }
2446 
2447 /* sysfs supprt */
2448 
2449 struct ext4_attr {
2450 	struct attribute attr;
2451 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2452 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2453 			 const char *, size_t);
2454 	union {
2455 		int offset;
2456 		int deprecated_val;
2457 	} u;
2458 };
2459 
2460 static int parse_strtoull(const char *buf,
2461 		unsigned long long max, unsigned long long *value)
2462 {
2463 	int ret;
2464 
2465 	ret = kstrtoull(skip_spaces(buf), 0, value);
2466 	if (!ret && *value > max)
2467 		ret = -EINVAL;
2468 	return ret;
2469 }
2470 
2471 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2472 					      struct ext4_sb_info *sbi,
2473 					      char *buf)
2474 {
2475 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2476 		(s64) EXT4_C2B(sbi,
2477 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2478 }
2479 
2480 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2481 					 struct ext4_sb_info *sbi, char *buf)
2482 {
2483 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2484 
2485 	if (!sb->s_bdev->bd_part)
2486 		return snprintf(buf, PAGE_SIZE, "0\n");
2487 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2488 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2489 			 sbi->s_sectors_written_start) >> 1);
2490 }
2491 
2492 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2493 					  struct ext4_sb_info *sbi, char *buf)
2494 {
2495 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2496 
2497 	if (!sb->s_bdev->bd_part)
2498 		return snprintf(buf, PAGE_SIZE, "0\n");
2499 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2500 			(unsigned long long)(sbi->s_kbytes_written +
2501 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2502 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2503 }
2504 
2505 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2506 					  struct ext4_sb_info *sbi,
2507 					  const char *buf, size_t count)
2508 {
2509 	unsigned long t;
2510 	int ret;
2511 
2512 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2513 	if (ret)
2514 		return ret;
2515 
2516 	if (t && (!is_power_of_2(t) || t > 0x40000000))
2517 		return -EINVAL;
2518 
2519 	sbi->s_inode_readahead_blks = t;
2520 	return count;
2521 }
2522 
2523 static ssize_t sbi_ui_show(struct ext4_attr *a,
2524 			   struct ext4_sb_info *sbi, char *buf)
2525 {
2526 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2527 
2528 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2529 }
2530 
2531 static ssize_t sbi_ui_store(struct ext4_attr *a,
2532 			    struct ext4_sb_info *sbi,
2533 			    const char *buf, size_t count)
2534 {
2535 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2536 	unsigned long t;
2537 	int ret;
2538 
2539 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2540 	if (ret)
2541 		return ret;
2542 	*ui = t;
2543 	return count;
2544 }
2545 
2546 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2547 				  struct ext4_sb_info *sbi, char *buf)
2548 {
2549 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2550 		(unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2551 }
2552 
2553 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2554 				   struct ext4_sb_info *sbi,
2555 				   const char *buf, size_t count)
2556 {
2557 	unsigned long long val;
2558 	int ret;
2559 
2560 	if (parse_strtoull(buf, -1ULL, &val))
2561 		return -EINVAL;
2562 	ret = ext4_reserve_clusters(sbi, val);
2563 
2564 	return ret ? ret : count;
2565 }
2566 
2567 static ssize_t trigger_test_error(struct ext4_attr *a,
2568 				  struct ext4_sb_info *sbi,
2569 				  const char *buf, size_t count)
2570 {
2571 	int len = count;
2572 
2573 	if (!capable(CAP_SYS_ADMIN))
2574 		return -EPERM;
2575 
2576 	if (len && buf[len-1] == '\n')
2577 		len--;
2578 
2579 	if (len)
2580 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2581 	return count;
2582 }
2583 
2584 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2585 				   struct ext4_sb_info *sbi, char *buf)
2586 {
2587 	return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2588 }
2589 
2590 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2591 static struct ext4_attr ext4_attr_##_name = {			\
2592 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2593 	.show	= _show,					\
2594 	.store	= _store,					\
2595 	.u = {							\
2596 		.offset = offsetof(struct ext4_sb_info, _elname),\
2597 	},							\
2598 }
2599 #define EXT4_ATTR(name, mode, show, store) \
2600 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2601 
2602 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2603 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2604 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2605 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2606 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2607 #define ATTR_LIST(name) &ext4_attr_##name.attr
2608 #define EXT4_DEPRECATED_ATTR(_name, _val)	\
2609 static struct ext4_attr ext4_attr_##_name = {			\
2610 	.attr = {.name = __stringify(_name), .mode = 0444 },	\
2611 	.show	= sbi_deprecated_show,				\
2612 	.u = {							\
2613 		.deprecated_val = _val,				\
2614 	},							\
2615 }
2616 
2617 EXT4_RO_ATTR(delayed_allocation_blocks);
2618 EXT4_RO_ATTR(session_write_kbytes);
2619 EXT4_RO_ATTR(lifetime_write_kbytes);
2620 EXT4_RW_ATTR(reserved_clusters);
2621 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2622 		 inode_readahead_blks_store, s_inode_readahead_blks);
2623 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2624 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2625 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2626 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2627 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2628 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2629 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2630 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2631 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2632 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2633 EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
2634 EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
2635 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
2636 EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
2637 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
2638 EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
2639 
2640 static struct attribute *ext4_attrs[] = {
2641 	ATTR_LIST(delayed_allocation_blocks),
2642 	ATTR_LIST(session_write_kbytes),
2643 	ATTR_LIST(lifetime_write_kbytes),
2644 	ATTR_LIST(reserved_clusters),
2645 	ATTR_LIST(inode_readahead_blks),
2646 	ATTR_LIST(inode_goal),
2647 	ATTR_LIST(mb_stats),
2648 	ATTR_LIST(mb_max_to_scan),
2649 	ATTR_LIST(mb_min_to_scan),
2650 	ATTR_LIST(mb_order2_req),
2651 	ATTR_LIST(mb_stream_req),
2652 	ATTR_LIST(mb_group_prealloc),
2653 	ATTR_LIST(max_writeback_mb_bump),
2654 	ATTR_LIST(extent_max_zeroout_kb),
2655 	ATTR_LIST(trigger_fs_error),
2656 	ATTR_LIST(err_ratelimit_interval_ms),
2657 	ATTR_LIST(err_ratelimit_burst),
2658 	ATTR_LIST(warning_ratelimit_interval_ms),
2659 	ATTR_LIST(warning_ratelimit_burst),
2660 	ATTR_LIST(msg_ratelimit_interval_ms),
2661 	ATTR_LIST(msg_ratelimit_burst),
2662 	NULL,
2663 };
2664 
2665 /* Features this copy of ext4 supports */
2666 EXT4_INFO_ATTR(lazy_itable_init);
2667 EXT4_INFO_ATTR(batched_discard);
2668 EXT4_INFO_ATTR(meta_bg_resize);
2669 
2670 static struct attribute *ext4_feat_attrs[] = {
2671 	ATTR_LIST(lazy_itable_init),
2672 	ATTR_LIST(batched_discard),
2673 	ATTR_LIST(meta_bg_resize),
2674 	NULL,
2675 };
2676 
2677 static ssize_t ext4_attr_show(struct kobject *kobj,
2678 			      struct attribute *attr, char *buf)
2679 {
2680 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2681 						s_kobj);
2682 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2683 
2684 	return a->show ? a->show(a, sbi, buf) : 0;
2685 }
2686 
2687 static ssize_t ext4_attr_store(struct kobject *kobj,
2688 			       struct attribute *attr,
2689 			       const char *buf, size_t len)
2690 {
2691 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2692 						s_kobj);
2693 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2694 
2695 	return a->store ? a->store(a, sbi, buf, len) : 0;
2696 }
2697 
2698 static void ext4_sb_release(struct kobject *kobj)
2699 {
2700 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2701 						s_kobj);
2702 	complete(&sbi->s_kobj_unregister);
2703 }
2704 
2705 static const struct sysfs_ops ext4_attr_ops = {
2706 	.show	= ext4_attr_show,
2707 	.store	= ext4_attr_store,
2708 };
2709 
2710 static struct kobj_type ext4_ktype = {
2711 	.default_attrs	= ext4_attrs,
2712 	.sysfs_ops	= &ext4_attr_ops,
2713 	.release	= ext4_sb_release,
2714 };
2715 
2716 static void ext4_feat_release(struct kobject *kobj)
2717 {
2718 	complete(&ext4_feat->f_kobj_unregister);
2719 }
2720 
2721 static struct kobj_type ext4_feat_ktype = {
2722 	.default_attrs	= ext4_feat_attrs,
2723 	.sysfs_ops	= &ext4_attr_ops,
2724 	.release	= ext4_feat_release,
2725 };
2726 
2727 /*
2728  * Check whether this filesystem can be mounted based on
2729  * the features present and the RDONLY/RDWR mount requested.
2730  * Returns 1 if this filesystem can be mounted as requested,
2731  * 0 if it cannot be.
2732  */
2733 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2734 {
2735 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2736 		ext4_msg(sb, KERN_ERR,
2737 			"Couldn't mount because of "
2738 			"unsupported optional features (%x)",
2739 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2740 			~EXT4_FEATURE_INCOMPAT_SUPP));
2741 		return 0;
2742 	}
2743 
2744 	if (readonly)
2745 		return 1;
2746 
2747 	/* Check that feature set is OK for a read-write mount */
2748 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2749 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2750 			 "unsupported optional features (%x)",
2751 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2752 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2753 		return 0;
2754 	}
2755 	/*
2756 	 * Large file size enabled file system can only be mounted
2757 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2758 	 */
2759 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2760 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2761 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2762 				 "cannot be mounted RDWR without "
2763 				 "CONFIG_LBDAF");
2764 			return 0;
2765 		}
2766 	}
2767 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2768 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2769 		ext4_msg(sb, KERN_ERR,
2770 			 "Can't support bigalloc feature without "
2771 			 "extents feature\n");
2772 		return 0;
2773 	}
2774 
2775 #ifndef CONFIG_QUOTA
2776 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2777 	    !readonly) {
2778 		ext4_msg(sb, KERN_ERR,
2779 			 "Filesystem with quota feature cannot be mounted RDWR "
2780 			 "without CONFIG_QUOTA");
2781 		return 0;
2782 	}
2783 #endif  /* CONFIG_QUOTA */
2784 	return 1;
2785 }
2786 
2787 /*
2788  * This function is called once a day if we have errors logged
2789  * on the file system
2790  */
2791 static void print_daily_error_info(unsigned long arg)
2792 {
2793 	struct super_block *sb = (struct super_block *) arg;
2794 	struct ext4_sb_info *sbi;
2795 	struct ext4_super_block *es;
2796 
2797 	sbi = EXT4_SB(sb);
2798 	es = sbi->s_es;
2799 
2800 	if (es->s_error_count)
2801 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2802 			 le32_to_cpu(es->s_error_count));
2803 	if (es->s_first_error_time) {
2804 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2805 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2806 		       (int) sizeof(es->s_first_error_func),
2807 		       es->s_first_error_func,
2808 		       le32_to_cpu(es->s_first_error_line));
2809 		if (es->s_first_error_ino)
2810 			printk(": inode %u",
2811 			       le32_to_cpu(es->s_first_error_ino));
2812 		if (es->s_first_error_block)
2813 			printk(": block %llu", (unsigned long long)
2814 			       le64_to_cpu(es->s_first_error_block));
2815 		printk("\n");
2816 	}
2817 	if (es->s_last_error_time) {
2818 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2819 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2820 		       (int) sizeof(es->s_last_error_func),
2821 		       es->s_last_error_func,
2822 		       le32_to_cpu(es->s_last_error_line));
2823 		if (es->s_last_error_ino)
2824 			printk(": inode %u",
2825 			       le32_to_cpu(es->s_last_error_ino));
2826 		if (es->s_last_error_block)
2827 			printk(": block %llu", (unsigned long long)
2828 			       le64_to_cpu(es->s_last_error_block));
2829 		printk("\n");
2830 	}
2831 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2832 }
2833 
2834 /* Find next suitable group and run ext4_init_inode_table */
2835 static int ext4_run_li_request(struct ext4_li_request *elr)
2836 {
2837 	struct ext4_group_desc *gdp = NULL;
2838 	ext4_group_t group, ngroups;
2839 	struct super_block *sb;
2840 	unsigned long timeout = 0;
2841 	int ret = 0;
2842 
2843 	sb = elr->lr_super;
2844 	ngroups = EXT4_SB(sb)->s_groups_count;
2845 
2846 	sb_start_write(sb);
2847 	for (group = elr->lr_next_group; group < ngroups; group++) {
2848 		gdp = ext4_get_group_desc(sb, group, NULL);
2849 		if (!gdp) {
2850 			ret = 1;
2851 			break;
2852 		}
2853 
2854 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2855 			break;
2856 	}
2857 
2858 	if (group >= ngroups)
2859 		ret = 1;
2860 
2861 	if (!ret) {
2862 		timeout = jiffies;
2863 		ret = ext4_init_inode_table(sb, group,
2864 					    elr->lr_timeout ? 0 : 1);
2865 		if (elr->lr_timeout == 0) {
2866 			timeout = (jiffies - timeout) *
2867 				  elr->lr_sbi->s_li_wait_mult;
2868 			elr->lr_timeout = timeout;
2869 		}
2870 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2871 		elr->lr_next_group = group + 1;
2872 	}
2873 	sb_end_write(sb);
2874 
2875 	return ret;
2876 }
2877 
2878 /*
2879  * Remove lr_request from the list_request and free the
2880  * request structure. Should be called with li_list_mtx held
2881  */
2882 static void ext4_remove_li_request(struct ext4_li_request *elr)
2883 {
2884 	struct ext4_sb_info *sbi;
2885 
2886 	if (!elr)
2887 		return;
2888 
2889 	sbi = elr->lr_sbi;
2890 
2891 	list_del(&elr->lr_request);
2892 	sbi->s_li_request = NULL;
2893 	kfree(elr);
2894 }
2895 
2896 static void ext4_unregister_li_request(struct super_block *sb)
2897 {
2898 	mutex_lock(&ext4_li_mtx);
2899 	if (!ext4_li_info) {
2900 		mutex_unlock(&ext4_li_mtx);
2901 		return;
2902 	}
2903 
2904 	mutex_lock(&ext4_li_info->li_list_mtx);
2905 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2906 	mutex_unlock(&ext4_li_info->li_list_mtx);
2907 	mutex_unlock(&ext4_li_mtx);
2908 }
2909 
2910 static struct task_struct *ext4_lazyinit_task;
2911 
2912 /*
2913  * This is the function where ext4lazyinit thread lives. It walks
2914  * through the request list searching for next scheduled filesystem.
2915  * When such a fs is found, run the lazy initialization request
2916  * (ext4_rn_li_request) and keep track of the time spend in this
2917  * function. Based on that time we compute next schedule time of
2918  * the request. When walking through the list is complete, compute
2919  * next waking time and put itself into sleep.
2920  */
2921 static int ext4_lazyinit_thread(void *arg)
2922 {
2923 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2924 	struct list_head *pos, *n;
2925 	struct ext4_li_request *elr;
2926 	unsigned long next_wakeup, cur;
2927 
2928 	BUG_ON(NULL == eli);
2929 
2930 cont_thread:
2931 	while (true) {
2932 		next_wakeup = MAX_JIFFY_OFFSET;
2933 
2934 		mutex_lock(&eli->li_list_mtx);
2935 		if (list_empty(&eli->li_request_list)) {
2936 			mutex_unlock(&eli->li_list_mtx);
2937 			goto exit_thread;
2938 		}
2939 
2940 		list_for_each_safe(pos, n, &eli->li_request_list) {
2941 			elr = list_entry(pos, struct ext4_li_request,
2942 					 lr_request);
2943 
2944 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2945 				if (ext4_run_li_request(elr) != 0) {
2946 					/* error, remove the lazy_init job */
2947 					ext4_remove_li_request(elr);
2948 					continue;
2949 				}
2950 			}
2951 
2952 			if (time_before(elr->lr_next_sched, next_wakeup))
2953 				next_wakeup = elr->lr_next_sched;
2954 		}
2955 		mutex_unlock(&eli->li_list_mtx);
2956 
2957 		try_to_freeze();
2958 
2959 		cur = jiffies;
2960 		if ((time_after_eq(cur, next_wakeup)) ||
2961 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2962 			cond_resched();
2963 			continue;
2964 		}
2965 
2966 		schedule_timeout_interruptible(next_wakeup - cur);
2967 
2968 		if (kthread_should_stop()) {
2969 			ext4_clear_request_list();
2970 			goto exit_thread;
2971 		}
2972 	}
2973 
2974 exit_thread:
2975 	/*
2976 	 * It looks like the request list is empty, but we need
2977 	 * to check it under the li_list_mtx lock, to prevent any
2978 	 * additions into it, and of course we should lock ext4_li_mtx
2979 	 * to atomically free the list and ext4_li_info, because at
2980 	 * this point another ext4 filesystem could be registering
2981 	 * new one.
2982 	 */
2983 	mutex_lock(&ext4_li_mtx);
2984 	mutex_lock(&eli->li_list_mtx);
2985 	if (!list_empty(&eli->li_request_list)) {
2986 		mutex_unlock(&eli->li_list_mtx);
2987 		mutex_unlock(&ext4_li_mtx);
2988 		goto cont_thread;
2989 	}
2990 	mutex_unlock(&eli->li_list_mtx);
2991 	kfree(ext4_li_info);
2992 	ext4_li_info = NULL;
2993 	mutex_unlock(&ext4_li_mtx);
2994 
2995 	return 0;
2996 }
2997 
2998 static void ext4_clear_request_list(void)
2999 {
3000 	struct list_head *pos, *n;
3001 	struct ext4_li_request *elr;
3002 
3003 	mutex_lock(&ext4_li_info->li_list_mtx);
3004 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3005 		elr = list_entry(pos, struct ext4_li_request,
3006 				 lr_request);
3007 		ext4_remove_li_request(elr);
3008 	}
3009 	mutex_unlock(&ext4_li_info->li_list_mtx);
3010 }
3011 
3012 static int ext4_run_lazyinit_thread(void)
3013 {
3014 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3015 					 ext4_li_info, "ext4lazyinit");
3016 	if (IS_ERR(ext4_lazyinit_task)) {
3017 		int err = PTR_ERR(ext4_lazyinit_task);
3018 		ext4_clear_request_list();
3019 		kfree(ext4_li_info);
3020 		ext4_li_info = NULL;
3021 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3022 				 "initialization thread\n",
3023 				 err);
3024 		return err;
3025 	}
3026 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3027 	return 0;
3028 }
3029 
3030 /*
3031  * Check whether it make sense to run itable init. thread or not.
3032  * If there is at least one uninitialized inode table, return
3033  * corresponding group number, else the loop goes through all
3034  * groups and return total number of groups.
3035  */
3036 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3037 {
3038 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3039 	struct ext4_group_desc *gdp = NULL;
3040 
3041 	for (group = 0; group < ngroups; group++) {
3042 		gdp = ext4_get_group_desc(sb, group, NULL);
3043 		if (!gdp)
3044 			continue;
3045 
3046 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3047 			break;
3048 	}
3049 
3050 	return group;
3051 }
3052 
3053 static int ext4_li_info_new(void)
3054 {
3055 	struct ext4_lazy_init *eli = NULL;
3056 
3057 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3058 	if (!eli)
3059 		return -ENOMEM;
3060 
3061 	INIT_LIST_HEAD(&eli->li_request_list);
3062 	mutex_init(&eli->li_list_mtx);
3063 
3064 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3065 
3066 	ext4_li_info = eli;
3067 
3068 	return 0;
3069 }
3070 
3071 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3072 					    ext4_group_t start)
3073 {
3074 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3075 	struct ext4_li_request *elr;
3076 
3077 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3078 	if (!elr)
3079 		return NULL;
3080 
3081 	elr->lr_super = sb;
3082 	elr->lr_sbi = sbi;
3083 	elr->lr_next_group = start;
3084 
3085 	/*
3086 	 * Randomize first schedule time of the request to
3087 	 * spread the inode table initialization requests
3088 	 * better.
3089 	 */
3090 	elr->lr_next_sched = jiffies + (prandom_u32() %
3091 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3092 	return elr;
3093 }
3094 
3095 int ext4_register_li_request(struct super_block *sb,
3096 			     ext4_group_t first_not_zeroed)
3097 {
3098 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3099 	struct ext4_li_request *elr = NULL;
3100 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3101 	int ret = 0;
3102 
3103 	mutex_lock(&ext4_li_mtx);
3104 	if (sbi->s_li_request != NULL) {
3105 		/*
3106 		 * Reset timeout so it can be computed again, because
3107 		 * s_li_wait_mult might have changed.
3108 		 */
3109 		sbi->s_li_request->lr_timeout = 0;
3110 		goto out;
3111 	}
3112 
3113 	if (first_not_zeroed == ngroups ||
3114 	    (sb->s_flags & MS_RDONLY) ||
3115 	    !test_opt(sb, INIT_INODE_TABLE))
3116 		goto out;
3117 
3118 	elr = ext4_li_request_new(sb, first_not_zeroed);
3119 	if (!elr) {
3120 		ret = -ENOMEM;
3121 		goto out;
3122 	}
3123 
3124 	if (NULL == ext4_li_info) {
3125 		ret = ext4_li_info_new();
3126 		if (ret)
3127 			goto out;
3128 	}
3129 
3130 	mutex_lock(&ext4_li_info->li_list_mtx);
3131 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3132 	mutex_unlock(&ext4_li_info->li_list_mtx);
3133 
3134 	sbi->s_li_request = elr;
3135 	/*
3136 	 * set elr to NULL here since it has been inserted to
3137 	 * the request_list and the removal and free of it is
3138 	 * handled by ext4_clear_request_list from now on.
3139 	 */
3140 	elr = NULL;
3141 
3142 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3143 		ret = ext4_run_lazyinit_thread();
3144 		if (ret)
3145 			goto out;
3146 	}
3147 out:
3148 	mutex_unlock(&ext4_li_mtx);
3149 	if (ret)
3150 		kfree(elr);
3151 	return ret;
3152 }
3153 
3154 /*
3155  * We do not need to lock anything since this is called on
3156  * module unload.
3157  */
3158 static void ext4_destroy_lazyinit_thread(void)
3159 {
3160 	/*
3161 	 * If thread exited earlier
3162 	 * there's nothing to be done.
3163 	 */
3164 	if (!ext4_li_info || !ext4_lazyinit_task)
3165 		return;
3166 
3167 	kthread_stop(ext4_lazyinit_task);
3168 }
3169 
3170 static int set_journal_csum_feature_set(struct super_block *sb)
3171 {
3172 	int ret = 1;
3173 	int compat, incompat;
3174 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3175 
3176 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3177 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3178 		/* journal checksum v2 */
3179 		compat = 0;
3180 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3181 	} else {
3182 		/* journal checksum v1 */
3183 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3184 		incompat = 0;
3185 	}
3186 
3187 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3188 		ret = jbd2_journal_set_features(sbi->s_journal,
3189 				compat, 0,
3190 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3191 				incompat);
3192 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3193 		ret = jbd2_journal_set_features(sbi->s_journal,
3194 				compat, 0,
3195 				incompat);
3196 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3197 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3198 	} else {
3199 		jbd2_journal_clear_features(sbi->s_journal,
3200 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3201 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3202 				JBD2_FEATURE_INCOMPAT_CSUM_V2);
3203 	}
3204 
3205 	return ret;
3206 }
3207 
3208 /*
3209  * Note: calculating the overhead so we can be compatible with
3210  * historical BSD practice is quite difficult in the face of
3211  * clusters/bigalloc.  This is because multiple metadata blocks from
3212  * different block group can end up in the same allocation cluster.
3213  * Calculating the exact overhead in the face of clustered allocation
3214  * requires either O(all block bitmaps) in memory or O(number of block
3215  * groups**2) in time.  We will still calculate the superblock for
3216  * older file systems --- and if we come across with a bigalloc file
3217  * system with zero in s_overhead_clusters the estimate will be close to
3218  * correct especially for very large cluster sizes --- but for newer
3219  * file systems, it's better to calculate this figure once at mkfs
3220  * time, and store it in the superblock.  If the superblock value is
3221  * present (even for non-bigalloc file systems), we will use it.
3222  */
3223 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3224 			  char *buf)
3225 {
3226 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3227 	struct ext4_group_desc	*gdp;
3228 	ext4_fsblk_t		first_block, last_block, b;
3229 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3230 	int			s, j, count = 0;
3231 
3232 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3233 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3234 			sbi->s_itb_per_group + 2);
3235 
3236 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3237 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3238 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3239 	for (i = 0; i < ngroups; i++) {
3240 		gdp = ext4_get_group_desc(sb, i, NULL);
3241 		b = ext4_block_bitmap(sb, gdp);
3242 		if (b >= first_block && b <= last_block) {
3243 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3244 			count++;
3245 		}
3246 		b = ext4_inode_bitmap(sb, gdp);
3247 		if (b >= first_block && b <= last_block) {
3248 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3249 			count++;
3250 		}
3251 		b = ext4_inode_table(sb, gdp);
3252 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3253 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3254 				int c = EXT4_B2C(sbi, b - first_block);
3255 				ext4_set_bit(c, buf);
3256 				count++;
3257 			}
3258 		if (i != grp)
3259 			continue;
3260 		s = 0;
3261 		if (ext4_bg_has_super(sb, grp)) {
3262 			ext4_set_bit(s++, buf);
3263 			count++;
3264 		}
3265 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3266 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3267 			count++;
3268 		}
3269 	}
3270 	if (!count)
3271 		return 0;
3272 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3273 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3274 }
3275 
3276 /*
3277  * Compute the overhead and stash it in sbi->s_overhead
3278  */
3279 int ext4_calculate_overhead(struct super_block *sb)
3280 {
3281 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3282 	struct ext4_super_block *es = sbi->s_es;
3283 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3284 	ext4_fsblk_t overhead = 0;
3285 	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3286 
3287 	if (!buf)
3288 		return -ENOMEM;
3289 
3290 	/*
3291 	 * Compute the overhead (FS structures).  This is constant
3292 	 * for a given filesystem unless the number of block groups
3293 	 * changes so we cache the previous value until it does.
3294 	 */
3295 
3296 	/*
3297 	 * All of the blocks before first_data_block are overhead
3298 	 */
3299 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3300 
3301 	/*
3302 	 * Add the overhead found in each block group
3303 	 */
3304 	for (i = 0; i < ngroups; i++) {
3305 		int blks;
3306 
3307 		blks = count_overhead(sb, i, buf);
3308 		overhead += blks;
3309 		if (blks)
3310 			memset(buf, 0, PAGE_SIZE);
3311 		cond_resched();
3312 	}
3313 	/* Add the journal blocks as well */
3314 	if (sbi->s_journal)
3315 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3316 
3317 	sbi->s_overhead = overhead;
3318 	smp_wmb();
3319 	free_page((unsigned long) buf);
3320 	return 0;
3321 }
3322 
3323 
3324 static ext4_fsblk_t ext4_calculate_resv_clusters(struct super_block *sb)
3325 {
3326 	ext4_fsblk_t resv_clusters;
3327 
3328 	/*
3329 	 * There's no need to reserve anything when we aren't using extents.
3330 	 * The space estimates are exact, there are no unwritten extents,
3331 	 * hole punching doesn't need new metadata... This is needed especially
3332 	 * to keep ext2/3 backward compatibility.
3333 	 */
3334 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3335 		return 0;
3336 	/*
3337 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3338 	 * This should cover the situations where we can not afford to run
3339 	 * out of space like for example punch hole, or converting
3340 	 * uninitialized extents in delalloc path. In most cases such
3341 	 * allocation would require 1, or 2 blocks, higher numbers are
3342 	 * very rare.
3343 	 */
3344 	resv_clusters = ext4_blocks_count(EXT4_SB(sb)->s_es) >>
3345 			EXT4_SB(sb)->s_cluster_bits;
3346 
3347 	do_div(resv_clusters, 50);
3348 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3349 
3350 	return resv_clusters;
3351 }
3352 
3353 
3354 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3355 {
3356 	ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3357 				sbi->s_cluster_bits;
3358 
3359 	if (count >= clusters)
3360 		return -EINVAL;
3361 
3362 	atomic64_set(&sbi->s_resv_clusters, count);
3363 	return 0;
3364 }
3365 
3366 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3367 {
3368 	char *orig_data = kstrdup(data, GFP_KERNEL);
3369 	struct buffer_head *bh;
3370 	struct ext4_super_block *es = NULL;
3371 	struct ext4_sb_info *sbi;
3372 	ext4_fsblk_t block;
3373 	ext4_fsblk_t sb_block = get_sb_block(&data);
3374 	ext4_fsblk_t logical_sb_block;
3375 	unsigned long offset = 0;
3376 	unsigned long journal_devnum = 0;
3377 	unsigned long def_mount_opts;
3378 	struct inode *root;
3379 	char *cp;
3380 	const char *descr;
3381 	int ret = -ENOMEM;
3382 	int blocksize, clustersize;
3383 	unsigned int db_count;
3384 	unsigned int i;
3385 	int needs_recovery, has_huge_files, has_bigalloc;
3386 	__u64 blocks_count;
3387 	int err = 0;
3388 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3389 	ext4_group_t first_not_zeroed;
3390 
3391 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3392 	if (!sbi)
3393 		goto out_free_orig;
3394 
3395 	sbi->s_blockgroup_lock =
3396 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3397 	if (!sbi->s_blockgroup_lock) {
3398 		kfree(sbi);
3399 		goto out_free_orig;
3400 	}
3401 	sb->s_fs_info = sbi;
3402 	sbi->s_sb = sb;
3403 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3404 	sbi->s_sb_block = sb_block;
3405 	if (sb->s_bdev->bd_part)
3406 		sbi->s_sectors_written_start =
3407 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3408 
3409 	/* Cleanup superblock name */
3410 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3411 		*cp = '!';
3412 
3413 	/* -EINVAL is default */
3414 	ret = -EINVAL;
3415 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3416 	if (!blocksize) {
3417 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3418 		goto out_fail;
3419 	}
3420 
3421 	/*
3422 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3423 	 * block sizes.  We need to calculate the offset from buffer start.
3424 	 */
3425 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3426 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3427 		offset = do_div(logical_sb_block, blocksize);
3428 	} else {
3429 		logical_sb_block = sb_block;
3430 	}
3431 
3432 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3433 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3434 		goto out_fail;
3435 	}
3436 	/*
3437 	 * Note: s_es must be initialized as soon as possible because
3438 	 *       some ext4 macro-instructions depend on its value
3439 	 */
3440 	es = (struct ext4_super_block *) (bh->b_data + offset);
3441 	sbi->s_es = es;
3442 	sb->s_magic = le16_to_cpu(es->s_magic);
3443 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3444 		goto cantfind_ext4;
3445 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3446 
3447 	/* Warn if metadata_csum and gdt_csum are both set. */
3448 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3449 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3450 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3451 		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3452 			     "redundant flags; please run fsck.");
3453 
3454 	/* Check for a known checksum algorithm */
3455 	if (!ext4_verify_csum_type(sb, es)) {
3456 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3457 			 "unknown checksum algorithm.");
3458 		silent = 1;
3459 		goto cantfind_ext4;
3460 	}
3461 
3462 	/* Load the checksum driver */
3463 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3464 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3465 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3466 		if (IS_ERR(sbi->s_chksum_driver)) {
3467 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3468 			ret = PTR_ERR(sbi->s_chksum_driver);
3469 			sbi->s_chksum_driver = NULL;
3470 			goto failed_mount;
3471 		}
3472 	}
3473 
3474 	/* Check superblock checksum */
3475 	if (!ext4_superblock_csum_verify(sb, es)) {
3476 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3477 			 "invalid superblock checksum.  Run e2fsck?");
3478 		silent = 1;
3479 		goto cantfind_ext4;
3480 	}
3481 
3482 	/* Precompute checksum seed for all metadata */
3483 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3484 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3485 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3486 					       sizeof(es->s_uuid));
3487 
3488 	/* Set defaults before we parse the mount options */
3489 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3490 	set_opt(sb, INIT_INODE_TABLE);
3491 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3492 		set_opt(sb, DEBUG);
3493 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3494 		set_opt(sb, GRPID);
3495 	if (def_mount_opts & EXT4_DEFM_UID16)
3496 		set_opt(sb, NO_UID32);
3497 	/* xattr user namespace & acls are now defaulted on */
3498 	set_opt(sb, XATTR_USER);
3499 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3500 	set_opt(sb, POSIX_ACL);
3501 #endif
3502 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3503 		set_opt(sb, JOURNAL_DATA);
3504 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3505 		set_opt(sb, ORDERED_DATA);
3506 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3507 		set_opt(sb, WRITEBACK_DATA);
3508 
3509 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3510 		set_opt(sb, ERRORS_PANIC);
3511 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3512 		set_opt(sb, ERRORS_CONT);
3513 	else
3514 		set_opt(sb, ERRORS_RO);
3515 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3516 		set_opt(sb, BLOCK_VALIDITY);
3517 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3518 		set_opt(sb, DISCARD);
3519 
3520 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3521 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3522 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3523 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3524 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3525 
3526 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3527 		set_opt(sb, BARRIER);
3528 
3529 	/*
3530 	 * enable delayed allocation by default
3531 	 * Use -o nodelalloc to turn it off
3532 	 */
3533 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3534 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3535 		set_opt(sb, DELALLOC);
3536 
3537 	/*
3538 	 * set default s_li_wait_mult for lazyinit, for the case there is
3539 	 * no mount option specified.
3540 	 */
3541 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3542 
3543 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3544 			   &journal_devnum, &journal_ioprio, 0)) {
3545 		ext4_msg(sb, KERN_WARNING,
3546 			 "failed to parse options in superblock: %s",
3547 			 sbi->s_es->s_mount_opts);
3548 	}
3549 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3550 	if (!parse_options((char *) data, sb, &journal_devnum,
3551 			   &journal_ioprio, 0))
3552 		goto failed_mount;
3553 
3554 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3555 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3556 			    "with data=journal disables delayed "
3557 			    "allocation and O_DIRECT support!\n");
3558 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3559 			ext4_msg(sb, KERN_ERR, "can't mount with "
3560 				 "both data=journal and delalloc");
3561 			goto failed_mount;
3562 		}
3563 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3564 			ext4_msg(sb, KERN_ERR, "can't mount with "
3565 				 "both data=journal and dioread_nolock");
3566 			goto failed_mount;
3567 		}
3568 		if (test_opt(sb, DELALLOC))
3569 			clear_opt(sb, DELALLOC);
3570 	}
3571 
3572 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3573 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3574 
3575 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3576 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3577 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3578 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3579 		ext4_msg(sb, KERN_WARNING,
3580 		       "feature flags set on rev 0 fs, "
3581 		       "running e2fsck is recommended");
3582 
3583 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3584 		set_opt2(sb, HURD_COMPAT);
3585 		if (EXT4_HAS_INCOMPAT_FEATURE(sb,
3586 					      EXT4_FEATURE_INCOMPAT_64BIT)) {
3587 			ext4_msg(sb, KERN_ERR,
3588 				 "The Hurd can't support 64-bit file systems");
3589 			goto failed_mount;
3590 		}
3591 	}
3592 
3593 	if (IS_EXT2_SB(sb)) {
3594 		if (ext2_feature_set_ok(sb))
3595 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3596 				 "using the ext4 subsystem");
3597 		else {
3598 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3599 				 "to feature incompatibilities");
3600 			goto failed_mount;
3601 		}
3602 	}
3603 
3604 	if (IS_EXT3_SB(sb)) {
3605 		if (ext3_feature_set_ok(sb))
3606 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3607 				 "using the ext4 subsystem");
3608 		else {
3609 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3610 				 "to feature incompatibilities");
3611 			goto failed_mount;
3612 		}
3613 	}
3614 
3615 	/*
3616 	 * Check feature flags regardless of the revision level, since we
3617 	 * previously didn't change the revision level when setting the flags,
3618 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3619 	 */
3620 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3621 		goto failed_mount;
3622 
3623 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3624 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3625 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3626 		ext4_msg(sb, KERN_ERR,
3627 		       "Unsupported filesystem blocksize %d", blocksize);
3628 		goto failed_mount;
3629 	}
3630 
3631 	if (sb->s_blocksize != blocksize) {
3632 		/* Validate the filesystem blocksize */
3633 		if (!sb_set_blocksize(sb, blocksize)) {
3634 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3635 					blocksize);
3636 			goto failed_mount;
3637 		}
3638 
3639 		brelse(bh);
3640 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3641 		offset = do_div(logical_sb_block, blocksize);
3642 		bh = sb_bread(sb, logical_sb_block);
3643 		if (!bh) {
3644 			ext4_msg(sb, KERN_ERR,
3645 			       "Can't read superblock on 2nd try");
3646 			goto failed_mount;
3647 		}
3648 		es = (struct ext4_super_block *)(bh->b_data + offset);
3649 		sbi->s_es = es;
3650 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3651 			ext4_msg(sb, KERN_ERR,
3652 			       "Magic mismatch, very weird!");
3653 			goto failed_mount;
3654 		}
3655 	}
3656 
3657 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3658 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3659 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3660 						      has_huge_files);
3661 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3662 
3663 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3664 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3665 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3666 	} else {
3667 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3668 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3669 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3670 		    (!is_power_of_2(sbi->s_inode_size)) ||
3671 		    (sbi->s_inode_size > blocksize)) {
3672 			ext4_msg(sb, KERN_ERR,
3673 			       "unsupported inode size: %d",
3674 			       sbi->s_inode_size);
3675 			goto failed_mount;
3676 		}
3677 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3678 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3679 	}
3680 
3681 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3682 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3683 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3684 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3685 		    !is_power_of_2(sbi->s_desc_size)) {
3686 			ext4_msg(sb, KERN_ERR,
3687 			       "unsupported descriptor size %lu",
3688 			       sbi->s_desc_size);
3689 			goto failed_mount;
3690 		}
3691 	} else
3692 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3693 
3694 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3695 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3696 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3697 		goto cantfind_ext4;
3698 
3699 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3700 	if (sbi->s_inodes_per_block == 0)
3701 		goto cantfind_ext4;
3702 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3703 					sbi->s_inodes_per_block;
3704 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3705 	sbi->s_sbh = bh;
3706 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3707 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3708 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3709 
3710 	for (i = 0; i < 4; i++)
3711 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3712 	sbi->s_def_hash_version = es->s_def_hash_version;
3713 	if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
3714 		i = le32_to_cpu(es->s_flags);
3715 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3716 			sbi->s_hash_unsigned = 3;
3717 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3718 #ifdef __CHAR_UNSIGNED__
3719 			if (!(sb->s_flags & MS_RDONLY))
3720 				es->s_flags |=
3721 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3722 			sbi->s_hash_unsigned = 3;
3723 #else
3724 			if (!(sb->s_flags & MS_RDONLY))
3725 				es->s_flags |=
3726 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3727 #endif
3728 		}
3729 	}
3730 
3731 	/* Handle clustersize */
3732 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3733 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3734 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3735 	if (has_bigalloc) {
3736 		if (clustersize < blocksize) {
3737 			ext4_msg(sb, KERN_ERR,
3738 				 "cluster size (%d) smaller than "
3739 				 "block size (%d)", clustersize, blocksize);
3740 			goto failed_mount;
3741 		}
3742 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3743 			le32_to_cpu(es->s_log_block_size);
3744 		sbi->s_clusters_per_group =
3745 			le32_to_cpu(es->s_clusters_per_group);
3746 		if (sbi->s_clusters_per_group > blocksize * 8) {
3747 			ext4_msg(sb, KERN_ERR,
3748 				 "#clusters per group too big: %lu",
3749 				 sbi->s_clusters_per_group);
3750 			goto failed_mount;
3751 		}
3752 		if (sbi->s_blocks_per_group !=
3753 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3754 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3755 				 "clusters per group (%lu) inconsistent",
3756 				 sbi->s_blocks_per_group,
3757 				 sbi->s_clusters_per_group);
3758 			goto failed_mount;
3759 		}
3760 	} else {
3761 		if (clustersize != blocksize) {
3762 			ext4_warning(sb, "fragment/cluster size (%d) != "
3763 				     "block size (%d)", clustersize,
3764 				     blocksize);
3765 			clustersize = blocksize;
3766 		}
3767 		if (sbi->s_blocks_per_group > blocksize * 8) {
3768 			ext4_msg(sb, KERN_ERR,
3769 				 "#blocks per group too big: %lu",
3770 				 sbi->s_blocks_per_group);
3771 			goto failed_mount;
3772 		}
3773 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3774 		sbi->s_cluster_bits = 0;
3775 	}
3776 	sbi->s_cluster_ratio = clustersize / blocksize;
3777 
3778 	if (sbi->s_inodes_per_group > blocksize * 8) {
3779 		ext4_msg(sb, KERN_ERR,
3780 		       "#inodes per group too big: %lu",
3781 		       sbi->s_inodes_per_group);
3782 		goto failed_mount;
3783 	}
3784 
3785 	/* Do we have standard group size of clustersize * 8 blocks ? */
3786 	if (sbi->s_blocks_per_group == clustersize << 3)
3787 		set_opt2(sb, STD_GROUP_SIZE);
3788 
3789 	/*
3790 	 * Test whether we have more sectors than will fit in sector_t,
3791 	 * and whether the max offset is addressable by the page cache.
3792 	 */
3793 	err = generic_check_addressable(sb->s_blocksize_bits,
3794 					ext4_blocks_count(es));
3795 	if (err) {
3796 		ext4_msg(sb, KERN_ERR, "filesystem"
3797 			 " too large to mount safely on this system");
3798 		if (sizeof(sector_t) < 8)
3799 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3800 		goto failed_mount;
3801 	}
3802 
3803 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3804 		goto cantfind_ext4;
3805 
3806 	/* check blocks count against device size */
3807 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3808 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3809 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3810 		       "exceeds size of device (%llu blocks)",
3811 		       ext4_blocks_count(es), blocks_count);
3812 		goto failed_mount;
3813 	}
3814 
3815 	/*
3816 	 * It makes no sense for the first data block to be beyond the end
3817 	 * of the filesystem.
3818 	 */
3819 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3820 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3821 			 "block %u is beyond end of filesystem (%llu)",
3822 			 le32_to_cpu(es->s_first_data_block),
3823 			 ext4_blocks_count(es));
3824 		goto failed_mount;
3825 	}
3826 	blocks_count = (ext4_blocks_count(es) -
3827 			le32_to_cpu(es->s_first_data_block) +
3828 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3829 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3830 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3831 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3832 		       "(block count %llu, first data block %u, "
3833 		       "blocks per group %lu)", sbi->s_groups_count,
3834 		       ext4_blocks_count(es),
3835 		       le32_to_cpu(es->s_first_data_block),
3836 		       EXT4_BLOCKS_PER_GROUP(sb));
3837 		goto failed_mount;
3838 	}
3839 	sbi->s_groups_count = blocks_count;
3840 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3841 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3842 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3843 		   EXT4_DESC_PER_BLOCK(sb);
3844 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3845 					  sizeof(struct buffer_head *),
3846 					  GFP_KERNEL);
3847 	if (sbi->s_group_desc == NULL) {
3848 		ext4_msg(sb, KERN_ERR, "not enough memory");
3849 		ret = -ENOMEM;
3850 		goto failed_mount;
3851 	}
3852 
3853 	if (ext4_proc_root)
3854 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3855 
3856 	if (sbi->s_proc)
3857 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3858 				 &ext4_seq_options_fops, sb);
3859 
3860 	bgl_lock_init(sbi->s_blockgroup_lock);
3861 
3862 	for (i = 0; i < db_count; i++) {
3863 		block = descriptor_loc(sb, logical_sb_block, i);
3864 		sbi->s_group_desc[i] = sb_bread(sb, block);
3865 		if (!sbi->s_group_desc[i]) {
3866 			ext4_msg(sb, KERN_ERR,
3867 			       "can't read group descriptor %d", i);
3868 			db_count = i;
3869 			goto failed_mount2;
3870 		}
3871 	}
3872 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3873 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3874 		goto failed_mount2;
3875 	}
3876 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3877 		if (!ext4_fill_flex_info(sb)) {
3878 			ext4_msg(sb, KERN_ERR,
3879 			       "unable to initialize "
3880 			       "flex_bg meta info!");
3881 			goto failed_mount2;
3882 		}
3883 
3884 	sbi->s_gdb_count = db_count;
3885 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3886 	spin_lock_init(&sbi->s_next_gen_lock);
3887 
3888 	init_timer(&sbi->s_err_report);
3889 	sbi->s_err_report.function = print_daily_error_info;
3890 	sbi->s_err_report.data = (unsigned long) sb;
3891 
3892 	/* Register extent status tree shrinker */
3893 	ext4_es_register_shrinker(sbi);
3894 
3895 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3896 			ext4_count_free_clusters(sb));
3897 	if (!err) {
3898 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3899 				ext4_count_free_inodes(sb));
3900 	}
3901 	if (!err) {
3902 		err = percpu_counter_init(&sbi->s_dirs_counter,
3903 				ext4_count_dirs(sb));
3904 	}
3905 	if (!err) {
3906 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3907 	}
3908 	if (!err) {
3909 		err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3910 	}
3911 	if (err) {
3912 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3913 		goto failed_mount3;
3914 	}
3915 
3916 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3917 	sbi->s_extent_max_zeroout_kb = 32;
3918 
3919 	/*
3920 	 * set up enough so that it can read an inode
3921 	 */
3922 	if (!test_opt(sb, NOLOAD) &&
3923 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3924 		sb->s_op = &ext4_sops;
3925 	else
3926 		sb->s_op = &ext4_nojournal_sops;
3927 	sb->s_export_op = &ext4_export_ops;
3928 	sb->s_xattr = ext4_xattr_handlers;
3929 #ifdef CONFIG_QUOTA
3930 	sb->dq_op = &ext4_quota_operations;
3931 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3932 		sb->s_qcop = &ext4_qctl_sysfile_operations;
3933 	else
3934 		sb->s_qcop = &ext4_qctl_operations;
3935 #endif
3936 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3937 
3938 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3939 	mutex_init(&sbi->s_orphan_lock);
3940 
3941 	sb->s_root = NULL;
3942 
3943 	needs_recovery = (es->s_last_orphan != 0 ||
3944 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3945 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3946 
3947 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3948 	    !(sb->s_flags & MS_RDONLY))
3949 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3950 			goto failed_mount3;
3951 
3952 	/*
3953 	 * The first inode we look at is the journal inode.  Don't try
3954 	 * root first: it may be modified in the journal!
3955 	 */
3956 	if (!test_opt(sb, NOLOAD) &&
3957 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3958 		if (ext4_load_journal(sb, es, journal_devnum))
3959 			goto failed_mount3;
3960 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3961 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3962 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3963 		       "suppressed and not mounted read-only");
3964 		goto failed_mount_wq;
3965 	} else {
3966 		clear_opt(sb, DATA_FLAGS);
3967 		sbi->s_journal = NULL;
3968 		needs_recovery = 0;
3969 		goto no_journal;
3970 	}
3971 
3972 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3973 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3974 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3975 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3976 		goto failed_mount_wq;
3977 	}
3978 
3979 	if (!set_journal_csum_feature_set(sb)) {
3980 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3981 			 "feature set");
3982 		goto failed_mount_wq;
3983 	}
3984 
3985 	/* We have now updated the journal if required, so we can
3986 	 * validate the data journaling mode. */
3987 	switch (test_opt(sb, DATA_FLAGS)) {
3988 	case 0:
3989 		/* No mode set, assume a default based on the journal
3990 		 * capabilities: ORDERED_DATA if the journal can
3991 		 * cope, else JOURNAL_DATA
3992 		 */
3993 		if (jbd2_journal_check_available_features
3994 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3995 			set_opt(sb, ORDERED_DATA);
3996 		else
3997 			set_opt(sb, JOURNAL_DATA);
3998 		break;
3999 
4000 	case EXT4_MOUNT_ORDERED_DATA:
4001 	case EXT4_MOUNT_WRITEBACK_DATA:
4002 		if (!jbd2_journal_check_available_features
4003 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4004 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4005 			       "requested data journaling mode");
4006 			goto failed_mount_wq;
4007 		}
4008 	default:
4009 		break;
4010 	}
4011 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4012 
4013 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4014 
4015 	/*
4016 	 * The journal may have updated the bg summary counts, so we
4017 	 * need to update the global counters.
4018 	 */
4019 	percpu_counter_set(&sbi->s_freeclusters_counter,
4020 			   ext4_count_free_clusters(sb));
4021 	percpu_counter_set(&sbi->s_freeinodes_counter,
4022 			   ext4_count_free_inodes(sb));
4023 	percpu_counter_set(&sbi->s_dirs_counter,
4024 			   ext4_count_dirs(sb));
4025 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
4026 
4027 no_journal:
4028 	if (ext4_mballoc_ready) {
4029 		sbi->s_mb_cache = ext4_xattr_create_cache(sb->s_id);
4030 		if (!sbi->s_mb_cache) {
4031 			ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4032 			goto failed_mount_wq;
4033 		}
4034 	}
4035 
4036 	/*
4037 	 * Get the # of file system overhead blocks from the
4038 	 * superblock if present.
4039 	 */
4040 	if (es->s_overhead_clusters)
4041 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4042 	else {
4043 		err = ext4_calculate_overhead(sb);
4044 		if (err)
4045 			goto failed_mount_wq;
4046 	}
4047 
4048 	/*
4049 	 * The maximum number of concurrent works can be high and
4050 	 * concurrency isn't really necessary.  Limit it to 1.
4051 	 */
4052 	EXT4_SB(sb)->rsv_conversion_wq =
4053 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4054 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4055 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4056 		ret = -ENOMEM;
4057 		goto failed_mount4;
4058 	}
4059 
4060 	/*
4061 	 * The jbd2_journal_load will have done any necessary log recovery,
4062 	 * so we can safely mount the rest of the filesystem now.
4063 	 */
4064 
4065 	root = ext4_iget(sb, EXT4_ROOT_INO);
4066 	if (IS_ERR(root)) {
4067 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4068 		ret = PTR_ERR(root);
4069 		root = NULL;
4070 		goto failed_mount4;
4071 	}
4072 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4073 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4074 		iput(root);
4075 		goto failed_mount4;
4076 	}
4077 	sb->s_root = d_make_root(root);
4078 	if (!sb->s_root) {
4079 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4080 		ret = -ENOMEM;
4081 		goto failed_mount4;
4082 	}
4083 
4084 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4085 		sb->s_flags |= MS_RDONLY;
4086 
4087 	/* determine the minimum size of new large inodes, if present */
4088 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4089 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4090 						     EXT4_GOOD_OLD_INODE_SIZE;
4091 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4092 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4093 			if (sbi->s_want_extra_isize <
4094 			    le16_to_cpu(es->s_want_extra_isize))
4095 				sbi->s_want_extra_isize =
4096 					le16_to_cpu(es->s_want_extra_isize);
4097 			if (sbi->s_want_extra_isize <
4098 			    le16_to_cpu(es->s_min_extra_isize))
4099 				sbi->s_want_extra_isize =
4100 					le16_to_cpu(es->s_min_extra_isize);
4101 		}
4102 	}
4103 	/* Check if enough inode space is available */
4104 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4105 							sbi->s_inode_size) {
4106 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4107 						       EXT4_GOOD_OLD_INODE_SIZE;
4108 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4109 			 "available");
4110 	}
4111 
4112 	err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sb));
4113 	if (err) {
4114 		ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4115 			 "reserved pool", ext4_calculate_resv_clusters(sb));
4116 		goto failed_mount4a;
4117 	}
4118 
4119 	err = ext4_setup_system_zone(sb);
4120 	if (err) {
4121 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4122 			 "zone (%d)", err);
4123 		goto failed_mount4a;
4124 	}
4125 
4126 	ext4_ext_init(sb);
4127 	err = ext4_mb_init(sb);
4128 	if (err) {
4129 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4130 			 err);
4131 		goto failed_mount5;
4132 	}
4133 
4134 	err = ext4_register_li_request(sb, first_not_zeroed);
4135 	if (err)
4136 		goto failed_mount6;
4137 
4138 	sbi->s_kobj.kset = ext4_kset;
4139 	init_completion(&sbi->s_kobj_unregister);
4140 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4141 				   "%s", sb->s_id);
4142 	if (err)
4143 		goto failed_mount7;
4144 
4145 #ifdef CONFIG_QUOTA
4146 	/* Enable quota usage during mount. */
4147 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4148 	    !(sb->s_flags & MS_RDONLY)) {
4149 		err = ext4_enable_quotas(sb);
4150 		if (err)
4151 			goto failed_mount8;
4152 	}
4153 #endif  /* CONFIG_QUOTA */
4154 
4155 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4156 	ext4_orphan_cleanup(sb, es);
4157 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4158 	if (needs_recovery) {
4159 		ext4_msg(sb, KERN_INFO, "recovery complete");
4160 		ext4_mark_recovery_complete(sb, es);
4161 	}
4162 	if (EXT4_SB(sb)->s_journal) {
4163 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4164 			descr = " journalled data mode";
4165 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4166 			descr = " ordered data mode";
4167 		else
4168 			descr = " writeback data mode";
4169 	} else
4170 		descr = "out journal";
4171 
4172 	if (test_opt(sb, DISCARD)) {
4173 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4174 		if (!blk_queue_discard(q))
4175 			ext4_msg(sb, KERN_WARNING,
4176 				 "mounting with \"discard\" option, but "
4177 				 "the device does not support discard");
4178 	}
4179 
4180 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4181 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4182 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4183 
4184 	if (es->s_error_count)
4185 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4186 
4187 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4188 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4189 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4190 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4191 
4192 	kfree(orig_data);
4193 	return 0;
4194 
4195 cantfind_ext4:
4196 	if (!silent)
4197 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4198 	goto failed_mount;
4199 
4200 #ifdef CONFIG_QUOTA
4201 failed_mount8:
4202 	kobject_del(&sbi->s_kobj);
4203 #endif
4204 failed_mount7:
4205 	ext4_unregister_li_request(sb);
4206 failed_mount6:
4207 	ext4_mb_release(sb);
4208 failed_mount5:
4209 	ext4_ext_release(sb);
4210 	ext4_release_system_zone(sb);
4211 failed_mount4a:
4212 	dput(sb->s_root);
4213 	sb->s_root = NULL;
4214 failed_mount4:
4215 	ext4_msg(sb, KERN_ERR, "mount failed");
4216 	if (EXT4_SB(sb)->rsv_conversion_wq)
4217 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4218 failed_mount_wq:
4219 	if (sbi->s_journal) {
4220 		jbd2_journal_destroy(sbi->s_journal);
4221 		sbi->s_journal = NULL;
4222 	}
4223 failed_mount3:
4224 	ext4_es_unregister_shrinker(sbi);
4225 	del_timer_sync(&sbi->s_err_report);
4226 	if (sbi->s_flex_groups)
4227 		ext4_kvfree(sbi->s_flex_groups);
4228 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4229 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4230 	percpu_counter_destroy(&sbi->s_dirs_counter);
4231 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4232 	percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4233 	if (sbi->s_mmp_tsk)
4234 		kthread_stop(sbi->s_mmp_tsk);
4235 failed_mount2:
4236 	for (i = 0; i < db_count; i++)
4237 		brelse(sbi->s_group_desc[i]);
4238 	ext4_kvfree(sbi->s_group_desc);
4239 failed_mount:
4240 	if (sbi->s_chksum_driver)
4241 		crypto_free_shash(sbi->s_chksum_driver);
4242 	if (sbi->s_proc) {
4243 		remove_proc_entry("options", sbi->s_proc);
4244 		remove_proc_entry(sb->s_id, ext4_proc_root);
4245 	}
4246 #ifdef CONFIG_QUOTA
4247 	for (i = 0; i < MAXQUOTAS; i++)
4248 		kfree(sbi->s_qf_names[i]);
4249 #endif
4250 	ext4_blkdev_remove(sbi);
4251 	brelse(bh);
4252 out_fail:
4253 	sb->s_fs_info = NULL;
4254 	kfree(sbi->s_blockgroup_lock);
4255 	kfree(sbi);
4256 out_free_orig:
4257 	kfree(orig_data);
4258 	return err ? err : ret;
4259 }
4260 
4261 /*
4262  * Setup any per-fs journal parameters now.  We'll do this both on
4263  * initial mount, once the journal has been initialised but before we've
4264  * done any recovery; and again on any subsequent remount.
4265  */
4266 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4267 {
4268 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4269 
4270 	journal->j_commit_interval = sbi->s_commit_interval;
4271 	journal->j_min_batch_time = sbi->s_min_batch_time;
4272 	journal->j_max_batch_time = sbi->s_max_batch_time;
4273 
4274 	write_lock(&journal->j_state_lock);
4275 	if (test_opt(sb, BARRIER))
4276 		journal->j_flags |= JBD2_BARRIER;
4277 	else
4278 		journal->j_flags &= ~JBD2_BARRIER;
4279 	if (test_opt(sb, DATA_ERR_ABORT))
4280 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4281 	else
4282 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4283 	write_unlock(&journal->j_state_lock);
4284 }
4285 
4286 static journal_t *ext4_get_journal(struct super_block *sb,
4287 				   unsigned int journal_inum)
4288 {
4289 	struct inode *journal_inode;
4290 	journal_t *journal;
4291 
4292 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4293 
4294 	/* First, test for the existence of a valid inode on disk.  Bad
4295 	 * things happen if we iget() an unused inode, as the subsequent
4296 	 * iput() will try to delete it. */
4297 
4298 	journal_inode = ext4_iget(sb, journal_inum);
4299 	if (IS_ERR(journal_inode)) {
4300 		ext4_msg(sb, KERN_ERR, "no journal found");
4301 		return NULL;
4302 	}
4303 	if (!journal_inode->i_nlink) {
4304 		make_bad_inode(journal_inode);
4305 		iput(journal_inode);
4306 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4307 		return NULL;
4308 	}
4309 
4310 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4311 		  journal_inode, journal_inode->i_size);
4312 	if (!S_ISREG(journal_inode->i_mode)) {
4313 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4314 		iput(journal_inode);
4315 		return NULL;
4316 	}
4317 
4318 	journal = jbd2_journal_init_inode(journal_inode);
4319 	if (!journal) {
4320 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4321 		iput(journal_inode);
4322 		return NULL;
4323 	}
4324 	journal->j_private = sb;
4325 	ext4_init_journal_params(sb, journal);
4326 	return journal;
4327 }
4328 
4329 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4330 				       dev_t j_dev)
4331 {
4332 	struct buffer_head *bh;
4333 	journal_t *journal;
4334 	ext4_fsblk_t start;
4335 	ext4_fsblk_t len;
4336 	int hblock, blocksize;
4337 	ext4_fsblk_t sb_block;
4338 	unsigned long offset;
4339 	struct ext4_super_block *es;
4340 	struct block_device *bdev;
4341 
4342 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4343 
4344 	bdev = ext4_blkdev_get(j_dev, sb);
4345 	if (bdev == NULL)
4346 		return NULL;
4347 
4348 	blocksize = sb->s_blocksize;
4349 	hblock = bdev_logical_block_size(bdev);
4350 	if (blocksize < hblock) {
4351 		ext4_msg(sb, KERN_ERR,
4352 			"blocksize too small for journal device");
4353 		goto out_bdev;
4354 	}
4355 
4356 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4357 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4358 	set_blocksize(bdev, blocksize);
4359 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4360 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4361 		       "external journal");
4362 		goto out_bdev;
4363 	}
4364 
4365 	es = (struct ext4_super_block *) (bh->b_data + offset);
4366 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4367 	    !(le32_to_cpu(es->s_feature_incompat) &
4368 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4369 		ext4_msg(sb, KERN_ERR, "external journal has "
4370 					"bad superblock");
4371 		brelse(bh);
4372 		goto out_bdev;
4373 	}
4374 
4375 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4376 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4377 		brelse(bh);
4378 		goto out_bdev;
4379 	}
4380 
4381 	len = ext4_blocks_count(es);
4382 	start = sb_block + 1;
4383 	brelse(bh);	/* we're done with the superblock */
4384 
4385 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4386 					start, len, blocksize);
4387 	if (!journal) {
4388 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4389 		goto out_bdev;
4390 	}
4391 	journal->j_private = sb;
4392 	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4393 	wait_on_buffer(journal->j_sb_buffer);
4394 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4395 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4396 		goto out_journal;
4397 	}
4398 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4399 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4400 					"user (unsupported) - %d",
4401 			be32_to_cpu(journal->j_superblock->s_nr_users));
4402 		goto out_journal;
4403 	}
4404 	EXT4_SB(sb)->journal_bdev = bdev;
4405 	ext4_init_journal_params(sb, journal);
4406 	return journal;
4407 
4408 out_journal:
4409 	jbd2_journal_destroy(journal);
4410 out_bdev:
4411 	ext4_blkdev_put(bdev);
4412 	return NULL;
4413 }
4414 
4415 static int ext4_load_journal(struct super_block *sb,
4416 			     struct ext4_super_block *es,
4417 			     unsigned long journal_devnum)
4418 {
4419 	journal_t *journal;
4420 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4421 	dev_t journal_dev;
4422 	int err = 0;
4423 	int really_read_only;
4424 
4425 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4426 
4427 	if (journal_devnum &&
4428 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4429 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4430 			"numbers have changed");
4431 		journal_dev = new_decode_dev(journal_devnum);
4432 	} else
4433 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4434 
4435 	really_read_only = bdev_read_only(sb->s_bdev);
4436 
4437 	/*
4438 	 * Are we loading a blank journal or performing recovery after a
4439 	 * crash?  For recovery, we need to check in advance whether we
4440 	 * can get read-write access to the device.
4441 	 */
4442 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4443 		if (sb->s_flags & MS_RDONLY) {
4444 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4445 					"required on readonly filesystem");
4446 			if (really_read_only) {
4447 				ext4_msg(sb, KERN_ERR, "write access "
4448 					"unavailable, cannot proceed");
4449 				return -EROFS;
4450 			}
4451 			ext4_msg(sb, KERN_INFO, "write access will "
4452 			       "be enabled during recovery");
4453 		}
4454 	}
4455 
4456 	if (journal_inum && journal_dev) {
4457 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4458 		       "and inode journals!");
4459 		return -EINVAL;
4460 	}
4461 
4462 	if (journal_inum) {
4463 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4464 			return -EINVAL;
4465 	} else {
4466 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4467 			return -EINVAL;
4468 	}
4469 
4470 	if (!(journal->j_flags & JBD2_BARRIER))
4471 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4472 
4473 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4474 		err = jbd2_journal_wipe(journal, !really_read_only);
4475 	if (!err) {
4476 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4477 		if (save)
4478 			memcpy(save, ((char *) es) +
4479 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4480 		err = jbd2_journal_load(journal);
4481 		if (save)
4482 			memcpy(((char *) es) + EXT4_S_ERR_START,
4483 			       save, EXT4_S_ERR_LEN);
4484 		kfree(save);
4485 	}
4486 
4487 	if (err) {
4488 		ext4_msg(sb, KERN_ERR, "error loading journal");
4489 		jbd2_journal_destroy(journal);
4490 		return err;
4491 	}
4492 
4493 	EXT4_SB(sb)->s_journal = journal;
4494 	ext4_clear_journal_err(sb, es);
4495 
4496 	if (!really_read_only && journal_devnum &&
4497 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4498 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4499 
4500 		/* Make sure we flush the recovery flag to disk. */
4501 		ext4_commit_super(sb, 1);
4502 	}
4503 
4504 	return 0;
4505 }
4506 
4507 static int ext4_commit_super(struct super_block *sb, int sync)
4508 {
4509 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4510 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4511 	int error = 0;
4512 
4513 	if (!sbh || block_device_ejected(sb))
4514 		return error;
4515 	if (buffer_write_io_error(sbh)) {
4516 		/*
4517 		 * Oh, dear.  A previous attempt to write the
4518 		 * superblock failed.  This could happen because the
4519 		 * USB device was yanked out.  Or it could happen to
4520 		 * be a transient write error and maybe the block will
4521 		 * be remapped.  Nothing we can do but to retry the
4522 		 * write and hope for the best.
4523 		 */
4524 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4525 		       "superblock detected");
4526 		clear_buffer_write_io_error(sbh);
4527 		set_buffer_uptodate(sbh);
4528 	}
4529 	/*
4530 	 * If the file system is mounted read-only, don't update the
4531 	 * superblock write time.  This avoids updating the superblock
4532 	 * write time when we are mounting the root file system
4533 	 * read/only but we need to replay the journal; at that point,
4534 	 * for people who are east of GMT and who make their clock
4535 	 * tick in localtime for Windows bug-for-bug compatibility,
4536 	 * the clock is set in the future, and this will cause e2fsck
4537 	 * to complain and force a full file system check.
4538 	 */
4539 	if (!(sb->s_flags & MS_RDONLY))
4540 		es->s_wtime = cpu_to_le32(get_seconds());
4541 	if (sb->s_bdev->bd_part)
4542 		es->s_kbytes_written =
4543 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4544 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4545 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4546 	else
4547 		es->s_kbytes_written =
4548 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4549 	ext4_free_blocks_count_set(es,
4550 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4551 				&EXT4_SB(sb)->s_freeclusters_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 	err = ext4_journal_get_write_access(handle, bh);
5371 	if (err) {
5372 		brelse(bh);
5373 		goto out;
5374 	}
5375 	lock_buffer(bh);
5376 	memcpy(bh->b_data+offset, data, len);
5377 	flush_dcache_page(bh->b_page);
5378 	unlock_buffer(bh);
5379 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5380 	brelse(bh);
5381 out:
5382 	if (err)
5383 		return err;
5384 	if (inode->i_size < off + len) {
5385 		i_size_write(inode, off + len);
5386 		EXT4_I(inode)->i_disksize = inode->i_size;
5387 		ext4_mark_inode_dirty(handle, inode);
5388 	}
5389 	return len;
5390 }
5391 
5392 #endif
5393 
5394 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5395 		       const char *dev_name, void *data)
5396 {
5397 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5398 }
5399 
5400 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5401 static inline void register_as_ext2(void)
5402 {
5403 	int err = register_filesystem(&ext2_fs_type);
5404 	if (err)
5405 		printk(KERN_WARNING
5406 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5407 }
5408 
5409 static inline void unregister_as_ext2(void)
5410 {
5411 	unregister_filesystem(&ext2_fs_type);
5412 }
5413 
5414 static inline int ext2_feature_set_ok(struct super_block *sb)
5415 {
5416 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5417 		return 0;
5418 	if (sb->s_flags & MS_RDONLY)
5419 		return 1;
5420 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5421 		return 0;
5422 	return 1;
5423 }
5424 #else
5425 static inline void register_as_ext2(void) { }
5426 static inline void unregister_as_ext2(void) { }
5427 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5428 #endif
5429 
5430 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5431 static inline void register_as_ext3(void)
5432 {
5433 	int err = register_filesystem(&ext3_fs_type);
5434 	if (err)
5435 		printk(KERN_WARNING
5436 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5437 }
5438 
5439 static inline void unregister_as_ext3(void)
5440 {
5441 	unregister_filesystem(&ext3_fs_type);
5442 }
5443 
5444 static inline int ext3_feature_set_ok(struct super_block *sb)
5445 {
5446 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5447 		return 0;
5448 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5449 		return 0;
5450 	if (sb->s_flags & MS_RDONLY)
5451 		return 1;
5452 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5453 		return 0;
5454 	return 1;
5455 }
5456 #else
5457 static inline void register_as_ext3(void) { }
5458 static inline void unregister_as_ext3(void) { }
5459 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5460 #endif
5461 
5462 static struct file_system_type ext4_fs_type = {
5463 	.owner		= THIS_MODULE,
5464 	.name		= "ext4",
5465 	.mount		= ext4_mount,
5466 	.kill_sb	= kill_block_super,
5467 	.fs_flags	= FS_REQUIRES_DEV,
5468 };
5469 MODULE_ALIAS_FS("ext4");
5470 
5471 static int __init ext4_init_feat_adverts(void)
5472 {
5473 	struct ext4_features *ef;
5474 	int ret = -ENOMEM;
5475 
5476 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5477 	if (!ef)
5478 		goto out;
5479 
5480 	ef->f_kobj.kset = ext4_kset;
5481 	init_completion(&ef->f_kobj_unregister);
5482 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5483 				   "features");
5484 	if (ret) {
5485 		kfree(ef);
5486 		goto out;
5487 	}
5488 
5489 	ext4_feat = ef;
5490 	ret = 0;
5491 out:
5492 	return ret;
5493 }
5494 
5495 static void ext4_exit_feat_adverts(void)
5496 {
5497 	kobject_put(&ext4_feat->f_kobj);
5498 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5499 	kfree(ext4_feat);
5500 }
5501 
5502 /* Shared across all ext4 file systems */
5503 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5504 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5505 
5506 static int __init ext4_init_fs(void)
5507 {
5508 	int i, err;
5509 
5510 	ext4_li_info = NULL;
5511 	mutex_init(&ext4_li_mtx);
5512 
5513 	/* Build-time check for flags consistency */
5514 	ext4_check_flag_values();
5515 
5516 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5517 		mutex_init(&ext4__aio_mutex[i]);
5518 		init_waitqueue_head(&ext4__ioend_wq[i]);
5519 	}
5520 
5521 	err = ext4_init_es();
5522 	if (err)
5523 		return err;
5524 
5525 	err = ext4_init_pageio();
5526 	if (err)
5527 		goto out7;
5528 
5529 	err = ext4_init_system_zone();
5530 	if (err)
5531 		goto out6;
5532 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5533 	if (!ext4_kset) {
5534 		err = -ENOMEM;
5535 		goto out5;
5536 	}
5537 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5538 
5539 	err = ext4_init_feat_adverts();
5540 	if (err)
5541 		goto out4;
5542 
5543 	err = ext4_init_mballoc();
5544 	if (err)
5545 		goto out2;
5546 	else
5547 		ext4_mballoc_ready = 1;
5548 	err = init_inodecache();
5549 	if (err)
5550 		goto out1;
5551 	register_as_ext3();
5552 	register_as_ext2();
5553 	err = register_filesystem(&ext4_fs_type);
5554 	if (err)
5555 		goto out;
5556 
5557 	return 0;
5558 out:
5559 	unregister_as_ext2();
5560 	unregister_as_ext3();
5561 	destroy_inodecache();
5562 out1:
5563 	ext4_mballoc_ready = 0;
5564 	ext4_exit_mballoc();
5565 out2:
5566 	ext4_exit_feat_adverts();
5567 out4:
5568 	if (ext4_proc_root)
5569 		remove_proc_entry("fs/ext4", NULL);
5570 	kset_unregister(ext4_kset);
5571 out5:
5572 	ext4_exit_system_zone();
5573 out6:
5574 	ext4_exit_pageio();
5575 out7:
5576 	ext4_exit_es();
5577 
5578 	return err;
5579 }
5580 
5581 static void __exit ext4_exit_fs(void)
5582 {
5583 	ext4_destroy_lazyinit_thread();
5584 	unregister_as_ext2();
5585 	unregister_as_ext3();
5586 	unregister_filesystem(&ext4_fs_type);
5587 	destroy_inodecache();
5588 	ext4_exit_mballoc();
5589 	ext4_exit_feat_adverts();
5590 	remove_proc_entry("fs/ext4", NULL);
5591 	kset_unregister(ext4_kset);
5592 	ext4_exit_system_zone();
5593 	ext4_exit_pageio();
5594 	ext4_exit_es();
5595 }
5596 
5597 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5598 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5599 MODULE_LICENSE("GPL");
5600 module_init(ext4_init_fs)
5601 module_exit(ext4_exit_fs)
5602