xref: /linux/fs/ext4/super.c (revision 615f2e5c531bc57d5a190f321d697988e950ae4d)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/jbd2.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/parser.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/proc_fs.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/cleancache.h>
42 #include <asm/uaccess.h>
43 
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46 
47 #include "ext4.h"
48 #include "ext4_extents.h"	/* Needed for trace points definition */
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/ext4.h>
56 
57 static struct proc_dir_entry *ext4_proc_root;
58 static struct kset *ext4_kset;
59 static struct ext4_lazy_init *ext4_li_info;
60 static struct mutex ext4_li_mtx;
61 static struct ext4_features *ext4_feat;
62 
63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
64 			     unsigned long journal_devnum);
65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
66 static int ext4_commit_super(struct super_block *sb, int sync);
67 static void ext4_mark_recovery_complete(struct super_block *sb,
68 					struct ext4_super_block *es);
69 static void ext4_clear_journal_err(struct super_block *sb,
70 				   struct ext4_super_block *es);
71 static int ext4_sync_fs(struct super_block *sb, int wait);
72 static int ext4_remount(struct super_block *sb, int *flags, char *data);
73 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
74 static int ext4_unfreeze(struct super_block *sb);
75 static int ext4_freeze(struct super_block *sb);
76 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
77 		       const char *dev_name, void *data);
78 static inline int ext2_feature_set_ok(struct super_block *sb);
79 static inline int ext3_feature_set_ok(struct super_block *sb);
80 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
81 static void ext4_destroy_lazyinit_thread(void);
82 static void ext4_unregister_li_request(struct super_block *sb);
83 static void ext4_clear_request_list(void);
84 
85 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
86 static struct file_system_type ext2_fs_type = {
87 	.owner		= THIS_MODULE,
88 	.name		= "ext2",
89 	.mount		= ext4_mount,
90 	.kill_sb	= kill_block_super,
91 	.fs_flags	= FS_REQUIRES_DEV,
92 };
93 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
94 #else
95 #define IS_EXT2_SB(sb) (0)
96 #endif
97 
98 
99 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
100 static struct file_system_type ext3_fs_type = {
101 	.owner		= THIS_MODULE,
102 	.name		= "ext3",
103 	.mount		= ext4_mount,
104 	.kill_sb	= kill_block_super,
105 	.fs_flags	= FS_REQUIRES_DEV,
106 };
107 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
108 #else
109 #define IS_EXT3_SB(sb) (0)
110 #endif
111 
112 static int ext4_verify_csum_type(struct super_block *sb,
113 				 struct ext4_super_block *es)
114 {
115 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
116 					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
117 		return 1;
118 
119 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
120 }
121 
122 static __le32 ext4_superblock_csum(struct super_block *sb,
123 				   struct ext4_super_block *es)
124 {
125 	struct ext4_sb_info *sbi = EXT4_SB(sb);
126 	int offset = offsetof(struct ext4_super_block, s_checksum);
127 	__u32 csum;
128 
129 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
130 
131 	return cpu_to_le32(csum);
132 }
133 
134 int ext4_superblock_csum_verify(struct super_block *sb,
135 				struct ext4_super_block *es)
136 {
137 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
138 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
139 		return 1;
140 
141 	return es->s_checksum == ext4_superblock_csum(sb, es);
142 }
143 
144 void ext4_superblock_csum_set(struct super_block *sb)
145 {
146 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
147 
148 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
149 		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
150 		return;
151 
152 	es->s_checksum = ext4_superblock_csum(sb, es);
153 }
154 
155 void *ext4_kvmalloc(size_t size, gfp_t flags)
156 {
157 	void *ret;
158 
159 	ret = kmalloc(size, flags);
160 	if (!ret)
161 		ret = __vmalloc(size, flags, PAGE_KERNEL);
162 	return ret;
163 }
164 
165 void *ext4_kvzalloc(size_t size, gfp_t flags)
166 {
167 	void *ret;
168 
169 	ret = kzalloc(size, flags);
170 	if (!ret)
171 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
172 	return ret;
173 }
174 
175 void ext4_kvfree(void *ptr)
176 {
177 	if (is_vmalloc_addr(ptr))
178 		vfree(ptr);
179 	else
180 		kfree(ptr);
181 
182 }
183 
184 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
185 			       struct ext4_group_desc *bg)
186 {
187 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
188 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
189 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
190 }
191 
192 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
193 			       struct ext4_group_desc *bg)
194 {
195 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
196 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
197 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
198 }
199 
200 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
201 			      struct ext4_group_desc *bg)
202 {
203 	return le32_to_cpu(bg->bg_inode_table_lo) |
204 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
205 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
206 }
207 
208 __u32 ext4_free_group_clusters(struct super_block *sb,
209 			       struct ext4_group_desc *bg)
210 {
211 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
212 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
213 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
214 }
215 
216 __u32 ext4_free_inodes_count(struct super_block *sb,
217 			      struct ext4_group_desc *bg)
218 {
219 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
220 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
221 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
222 }
223 
224 __u32 ext4_used_dirs_count(struct super_block *sb,
225 			      struct ext4_group_desc *bg)
226 {
227 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
228 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
229 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
230 }
231 
232 __u32 ext4_itable_unused_count(struct super_block *sb,
233 			      struct ext4_group_desc *bg)
234 {
235 	return le16_to_cpu(bg->bg_itable_unused_lo) |
236 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
237 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
238 }
239 
240 void ext4_block_bitmap_set(struct super_block *sb,
241 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
242 {
243 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
244 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
245 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
246 }
247 
248 void ext4_inode_bitmap_set(struct super_block *sb,
249 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
250 {
251 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
252 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
253 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
254 }
255 
256 void ext4_inode_table_set(struct super_block *sb,
257 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
258 {
259 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
260 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
261 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
262 }
263 
264 void ext4_free_group_clusters_set(struct super_block *sb,
265 				  struct ext4_group_desc *bg, __u32 count)
266 {
267 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
268 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
269 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
270 }
271 
272 void ext4_free_inodes_set(struct super_block *sb,
273 			  struct ext4_group_desc *bg, __u32 count)
274 {
275 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
276 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
277 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
278 }
279 
280 void ext4_used_dirs_set(struct super_block *sb,
281 			  struct ext4_group_desc *bg, __u32 count)
282 {
283 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
284 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
285 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
286 }
287 
288 void ext4_itable_unused_set(struct super_block *sb,
289 			  struct ext4_group_desc *bg, __u32 count)
290 {
291 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
292 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
293 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
294 }
295 
296 
297 static void __save_error_info(struct super_block *sb, const char *func,
298 			    unsigned int line)
299 {
300 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
301 
302 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
303 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
304 	es->s_last_error_time = cpu_to_le32(get_seconds());
305 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
306 	es->s_last_error_line = cpu_to_le32(line);
307 	if (!es->s_first_error_time) {
308 		es->s_first_error_time = es->s_last_error_time;
309 		strncpy(es->s_first_error_func, func,
310 			sizeof(es->s_first_error_func));
311 		es->s_first_error_line = cpu_to_le32(line);
312 		es->s_first_error_ino = es->s_last_error_ino;
313 		es->s_first_error_block = es->s_last_error_block;
314 	}
315 	/*
316 	 * Start the daily error reporting function if it hasn't been
317 	 * started already
318 	 */
319 	if (!es->s_error_count)
320 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
321 	le32_add_cpu(&es->s_error_count, 1);
322 }
323 
324 static void save_error_info(struct super_block *sb, const char *func,
325 			    unsigned int line)
326 {
327 	__save_error_info(sb, func, line);
328 	ext4_commit_super(sb, 1);
329 }
330 
331 /*
332  * The del_gendisk() function uninitializes the disk-specific data
333  * structures, including the bdi structure, without telling anyone
334  * else.  Once this happens, any attempt to call mark_buffer_dirty()
335  * (for example, by ext4_commit_super), will cause a kernel OOPS.
336  * This is a kludge to prevent these oops until we can put in a proper
337  * hook in del_gendisk() to inform the VFS and file system layers.
338  */
339 static int block_device_ejected(struct super_block *sb)
340 {
341 	struct inode *bd_inode = sb->s_bdev->bd_inode;
342 	struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
343 
344 	return bdi->dev == NULL;
345 }
346 
347 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
348 {
349 	struct super_block		*sb = journal->j_private;
350 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
351 	int				error = is_journal_aborted(journal);
352 	struct ext4_journal_cb_entry	*jce, *tmp;
353 
354 	spin_lock(&sbi->s_md_lock);
355 	list_for_each_entry_safe(jce, tmp, &txn->t_private_list, jce_list) {
356 		list_del_init(&jce->jce_list);
357 		spin_unlock(&sbi->s_md_lock);
358 		jce->jce_func(sb, jce, error);
359 		spin_lock(&sbi->s_md_lock);
360 	}
361 	spin_unlock(&sbi->s_md_lock);
362 }
363 
364 /* Deal with the reporting of failure conditions on a filesystem such as
365  * inconsistencies detected or read IO failures.
366  *
367  * On ext2, we can store the error state of the filesystem in the
368  * superblock.  That is not possible on ext4, because we may have other
369  * write ordering constraints on the superblock which prevent us from
370  * writing it out straight away; and given that the journal is about to
371  * be aborted, we can't rely on the current, or future, transactions to
372  * write out the superblock safely.
373  *
374  * We'll just use the jbd2_journal_abort() error code to record an error in
375  * the journal instead.  On recovery, the journal will complain about
376  * that error until we've noted it down and cleared it.
377  */
378 
379 static void ext4_handle_error(struct super_block *sb)
380 {
381 	if (sb->s_flags & MS_RDONLY)
382 		return;
383 
384 	if (!test_opt(sb, ERRORS_CONT)) {
385 		journal_t *journal = EXT4_SB(sb)->s_journal;
386 
387 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
388 		if (journal)
389 			jbd2_journal_abort(journal, -EIO);
390 	}
391 	if (test_opt(sb, ERRORS_RO)) {
392 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
393 		sb->s_flags |= MS_RDONLY;
394 	}
395 	if (test_opt(sb, ERRORS_PANIC))
396 		panic("EXT4-fs (device %s): panic forced after error\n",
397 			sb->s_id);
398 }
399 
400 void __ext4_error(struct super_block *sb, const char *function,
401 		  unsigned int line, const char *fmt, ...)
402 {
403 	struct va_format vaf;
404 	va_list args;
405 
406 	va_start(args, fmt);
407 	vaf.fmt = fmt;
408 	vaf.va = &args;
409 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
410 	       sb->s_id, function, line, current->comm, &vaf);
411 	va_end(args);
412 	save_error_info(sb, function, line);
413 
414 	ext4_handle_error(sb);
415 }
416 
417 void ext4_error_inode(struct inode *inode, const char *function,
418 		      unsigned int line, ext4_fsblk_t block,
419 		      const char *fmt, ...)
420 {
421 	va_list args;
422 	struct va_format vaf;
423 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
424 
425 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
426 	es->s_last_error_block = cpu_to_le64(block);
427 	save_error_info(inode->i_sb, function, line);
428 	va_start(args, fmt);
429 	vaf.fmt = fmt;
430 	vaf.va = &args;
431 	if (block)
432 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
433 		       "inode #%lu: block %llu: comm %s: %pV\n",
434 		       inode->i_sb->s_id, function, line, inode->i_ino,
435 		       block, current->comm, &vaf);
436 	else
437 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
438 		       "inode #%lu: comm %s: %pV\n",
439 		       inode->i_sb->s_id, function, line, inode->i_ino,
440 		       current->comm, &vaf);
441 	va_end(args);
442 
443 	ext4_handle_error(inode->i_sb);
444 }
445 
446 void ext4_error_file(struct file *file, const char *function,
447 		     unsigned int line, ext4_fsblk_t block,
448 		     const char *fmt, ...)
449 {
450 	va_list args;
451 	struct va_format vaf;
452 	struct ext4_super_block *es;
453 	struct inode *inode = file_inode(file);
454 	char pathname[80], *path;
455 
456 	es = EXT4_SB(inode->i_sb)->s_es;
457 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
458 	save_error_info(inode->i_sb, function, line);
459 	path = d_path(&(file->f_path), pathname, sizeof(pathname));
460 	if (IS_ERR(path))
461 		path = "(unknown)";
462 	va_start(args, fmt);
463 	vaf.fmt = fmt;
464 	vaf.va = &args;
465 	if (block)
466 		printk(KERN_CRIT
467 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
468 		       "block %llu: comm %s: path %s: %pV\n",
469 		       inode->i_sb->s_id, function, line, inode->i_ino,
470 		       block, current->comm, path, &vaf);
471 	else
472 		printk(KERN_CRIT
473 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
474 		       "comm %s: path %s: %pV\n",
475 		       inode->i_sb->s_id, function, line, inode->i_ino,
476 		       current->comm, path, &vaf);
477 	va_end(args);
478 
479 	ext4_handle_error(inode->i_sb);
480 }
481 
482 const char *ext4_decode_error(struct super_block *sb, int errno,
483 			      char nbuf[16])
484 {
485 	char *errstr = NULL;
486 
487 	switch (errno) {
488 	case -EIO:
489 		errstr = "IO failure";
490 		break;
491 	case -ENOMEM:
492 		errstr = "Out of memory";
493 		break;
494 	case -EROFS:
495 		if (!sb || (EXT4_SB(sb)->s_journal &&
496 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
497 			errstr = "Journal has aborted";
498 		else
499 			errstr = "Readonly filesystem";
500 		break;
501 	default:
502 		/* If the caller passed in an extra buffer for unknown
503 		 * errors, textualise them now.  Else we just return
504 		 * NULL. */
505 		if (nbuf) {
506 			/* Check for truncated error codes... */
507 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
508 				errstr = nbuf;
509 		}
510 		break;
511 	}
512 
513 	return errstr;
514 }
515 
516 /* __ext4_std_error decodes expected errors from journaling functions
517  * automatically and invokes the appropriate error response.  */
518 
519 void __ext4_std_error(struct super_block *sb, const char *function,
520 		      unsigned int line, int errno)
521 {
522 	char nbuf[16];
523 	const char *errstr;
524 
525 	/* Special case: if the error is EROFS, and we're not already
526 	 * inside a transaction, then there's really no point in logging
527 	 * an error. */
528 	if (errno == -EROFS && journal_current_handle() == NULL &&
529 	    (sb->s_flags & MS_RDONLY))
530 		return;
531 
532 	errstr = ext4_decode_error(sb, errno, nbuf);
533 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
534 	       sb->s_id, function, line, errstr);
535 	save_error_info(sb, function, line);
536 
537 	ext4_handle_error(sb);
538 }
539 
540 /*
541  * ext4_abort is a much stronger failure handler than ext4_error.  The
542  * abort function may be used to deal with unrecoverable failures such
543  * as journal IO errors or ENOMEM at a critical moment in log management.
544  *
545  * We unconditionally force the filesystem into an ABORT|READONLY state,
546  * unless the error response on the fs has been set to panic in which
547  * case we take the easy way out and panic immediately.
548  */
549 
550 void __ext4_abort(struct super_block *sb, const char *function,
551 		unsigned int line, const char *fmt, ...)
552 {
553 	va_list args;
554 
555 	save_error_info(sb, function, line);
556 	va_start(args, fmt);
557 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
558 	       function, line);
559 	vprintk(fmt, args);
560 	printk("\n");
561 	va_end(args);
562 
563 	if ((sb->s_flags & MS_RDONLY) == 0) {
564 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
565 		sb->s_flags |= MS_RDONLY;
566 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
567 		if (EXT4_SB(sb)->s_journal)
568 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
569 		save_error_info(sb, function, line);
570 	}
571 	if (test_opt(sb, ERRORS_PANIC))
572 		panic("EXT4-fs panic from previous error\n");
573 }
574 
575 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
576 {
577 	struct va_format vaf;
578 	va_list args;
579 
580 	va_start(args, fmt);
581 	vaf.fmt = fmt;
582 	vaf.va = &args;
583 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
584 	va_end(args);
585 }
586 
587 void __ext4_warning(struct super_block *sb, const char *function,
588 		    unsigned int line, const char *fmt, ...)
589 {
590 	struct va_format vaf;
591 	va_list args;
592 
593 	va_start(args, fmt);
594 	vaf.fmt = fmt;
595 	vaf.va = &args;
596 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
597 	       sb->s_id, function, line, &vaf);
598 	va_end(args);
599 }
600 
601 void __ext4_grp_locked_error(const char *function, unsigned int line,
602 			     struct super_block *sb, ext4_group_t grp,
603 			     unsigned long ino, ext4_fsblk_t block,
604 			     const char *fmt, ...)
605 __releases(bitlock)
606 __acquires(bitlock)
607 {
608 	struct va_format vaf;
609 	va_list args;
610 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
611 
612 	es->s_last_error_ino = cpu_to_le32(ino);
613 	es->s_last_error_block = cpu_to_le64(block);
614 	__save_error_info(sb, function, line);
615 
616 	va_start(args, fmt);
617 
618 	vaf.fmt = fmt;
619 	vaf.va = &args;
620 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
621 	       sb->s_id, function, line, grp);
622 	if (ino)
623 		printk(KERN_CONT "inode %lu: ", ino);
624 	if (block)
625 		printk(KERN_CONT "block %llu:", (unsigned long long) block);
626 	printk(KERN_CONT "%pV\n", &vaf);
627 	va_end(args);
628 
629 	if (test_opt(sb, ERRORS_CONT)) {
630 		ext4_commit_super(sb, 0);
631 		return;
632 	}
633 
634 	ext4_unlock_group(sb, grp);
635 	ext4_handle_error(sb);
636 	/*
637 	 * We only get here in the ERRORS_RO case; relocking the group
638 	 * may be dangerous, but nothing bad will happen since the
639 	 * filesystem will have already been marked read/only and the
640 	 * journal has been aborted.  We return 1 as a hint to callers
641 	 * who might what to use the return value from
642 	 * ext4_grp_locked_error() to distinguish between the
643 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
644 	 * aggressively from the ext4 function in question, with a
645 	 * more appropriate error code.
646 	 */
647 	ext4_lock_group(sb, grp);
648 	return;
649 }
650 
651 void ext4_update_dynamic_rev(struct super_block *sb)
652 {
653 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
654 
655 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
656 		return;
657 
658 	ext4_warning(sb,
659 		     "updating to rev %d because of new feature flag, "
660 		     "running e2fsck is recommended",
661 		     EXT4_DYNAMIC_REV);
662 
663 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
664 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
665 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
666 	/* leave es->s_feature_*compat flags alone */
667 	/* es->s_uuid will be set by e2fsck if empty */
668 
669 	/*
670 	 * The rest of the superblock fields should be zero, and if not it
671 	 * means they are likely already in use, so leave them alone.  We
672 	 * can leave it up to e2fsck to clean up any inconsistencies there.
673 	 */
674 }
675 
676 /*
677  * Open the external journal device
678  */
679 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
680 {
681 	struct block_device *bdev;
682 	char b[BDEVNAME_SIZE];
683 
684 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
685 	if (IS_ERR(bdev))
686 		goto fail;
687 	return bdev;
688 
689 fail:
690 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
691 			__bdevname(dev, b), PTR_ERR(bdev));
692 	return NULL;
693 }
694 
695 /*
696  * Release the journal device
697  */
698 static int ext4_blkdev_put(struct block_device *bdev)
699 {
700 	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
701 }
702 
703 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
704 {
705 	struct block_device *bdev;
706 	int ret = -ENODEV;
707 
708 	bdev = sbi->journal_bdev;
709 	if (bdev) {
710 		ret = ext4_blkdev_put(bdev);
711 		sbi->journal_bdev = NULL;
712 	}
713 	return ret;
714 }
715 
716 static inline struct inode *orphan_list_entry(struct list_head *l)
717 {
718 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
719 }
720 
721 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
722 {
723 	struct list_head *l;
724 
725 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
726 		 le32_to_cpu(sbi->s_es->s_last_orphan));
727 
728 	printk(KERN_ERR "sb_info orphan list:\n");
729 	list_for_each(l, &sbi->s_orphan) {
730 		struct inode *inode = orphan_list_entry(l);
731 		printk(KERN_ERR "  "
732 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
733 		       inode->i_sb->s_id, inode->i_ino, inode,
734 		       inode->i_mode, inode->i_nlink,
735 		       NEXT_ORPHAN(inode));
736 	}
737 }
738 
739 static void ext4_put_super(struct super_block *sb)
740 {
741 	struct ext4_sb_info *sbi = EXT4_SB(sb);
742 	struct ext4_super_block *es = sbi->s_es;
743 	int i, err;
744 
745 	ext4_unregister_li_request(sb);
746 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
747 
748 	flush_workqueue(sbi->dio_unwritten_wq);
749 	destroy_workqueue(sbi->dio_unwritten_wq);
750 
751 	if (sbi->s_journal) {
752 		err = jbd2_journal_destroy(sbi->s_journal);
753 		sbi->s_journal = NULL;
754 		if (err < 0)
755 			ext4_abort(sb, "Couldn't clean up the journal");
756 	}
757 
758 	ext4_es_unregister_shrinker(sb);
759 	del_timer(&sbi->s_err_report);
760 	ext4_release_system_zone(sb);
761 	ext4_mb_release(sb);
762 	ext4_ext_release(sb);
763 	ext4_xattr_put_super(sb);
764 
765 	if (!(sb->s_flags & MS_RDONLY)) {
766 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
767 		es->s_state = cpu_to_le16(sbi->s_mount_state);
768 	}
769 	if (!(sb->s_flags & MS_RDONLY))
770 		ext4_commit_super(sb, 1);
771 
772 	if (sbi->s_proc) {
773 		remove_proc_entry("options", sbi->s_proc);
774 		remove_proc_entry(sb->s_id, ext4_proc_root);
775 	}
776 	kobject_del(&sbi->s_kobj);
777 
778 	for (i = 0; i < sbi->s_gdb_count; i++)
779 		brelse(sbi->s_group_desc[i]);
780 	ext4_kvfree(sbi->s_group_desc);
781 	ext4_kvfree(sbi->s_flex_groups);
782 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
783 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
784 	percpu_counter_destroy(&sbi->s_dirs_counter);
785 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
786 	brelse(sbi->s_sbh);
787 #ifdef CONFIG_QUOTA
788 	for (i = 0; i < MAXQUOTAS; i++)
789 		kfree(sbi->s_qf_names[i]);
790 #endif
791 
792 	/* Debugging code just in case the in-memory inode orphan list
793 	 * isn't empty.  The on-disk one can be non-empty if we've
794 	 * detected an error and taken the fs readonly, but the
795 	 * in-memory list had better be clean by this point. */
796 	if (!list_empty(&sbi->s_orphan))
797 		dump_orphan_list(sb, sbi);
798 	J_ASSERT(list_empty(&sbi->s_orphan));
799 
800 	invalidate_bdev(sb->s_bdev);
801 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
802 		/*
803 		 * Invalidate the journal device's buffers.  We don't want them
804 		 * floating about in memory - the physical journal device may
805 		 * hotswapped, and it breaks the `ro-after' testing code.
806 		 */
807 		sync_blockdev(sbi->journal_bdev);
808 		invalidate_bdev(sbi->journal_bdev);
809 		ext4_blkdev_remove(sbi);
810 	}
811 	if (sbi->s_mmp_tsk)
812 		kthread_stop(sbi->s_mmp_tsk);
813 	sb->s_fs_info = NULL;
814 	/*
815 	 * Now that we are completely done shutting down the
816 	 * superblock, we need to actually destroy the kobject.
817 	 */
818 	kobject_put(&sbi->s_kobj);
819 	wait_for_completion(&sbi->s_kobj_unregister);
820 	if (sbi->s_chksum_driver)
821 		crypto_free_shash(sbi->s_chksum_driver);
822 	kfree(sbi->s_blockgroup_lock);
823 	kfree(sbi);
824 }
825 
826 static struct kmem_cache *ext4_inode_cachep;
827 
828 /*
829  * Called inside transaction, so use GFP_NOFS
830  */
831 static struct inode *ext4_alloc_inode(struct super_block *sb)
832 {
833 	struct ext4_inode_info *ei;
834 
835 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
836 	if (!ei)
837 		return NULL;
838 
839 	ei->vfs_inode.i_version = 1;
840 	INIT_LIST_HEAD(&ei->i_prealloc_list);
841 	spin_lock_init(&ei->i_prealloc_lock);
842 	ext4_es_init_tree(&ei->i_es_tree);
843 	rwlock_init(&ei->i_es_lock);
844 	INIT_LIST_HEAD(&ei->i_es_lru);
845 	ei->i_es_lru_nr = 0;
846 	ei->i_reserved_data_blocks = 0;
847 	ei->i_reserved_meta_blocks = 0;
848 	ei->i_allocated_meta_blocks = 0;
849 	ei->i_da_metadata_calc_len = 0;
850 	ei->i_da_metadata_calc_last_lblock = 0;
851 	spin_lock_init(&(ei->i_block_reservation_lock));
852 #ifdef CONFIG_QUOTA
853 	ei->i_reserved_quota = 0;
854 #endif
855 	ei->jinode = NULL;
856 	INIT_LIST_HEAD(&ei->i_completed_io_list);
857 	spin_lock_init(&ei->i_completed_io_lock);
858 	ei->i_sync_tid = 0;
859 	ei->i_datasync_tid = 0;
860 	atomic_set(&ei->i_ioend_count, 0);
861 	atomic_set(&ei->i_unwritten, 0);
862 	INIT_WORK(&ei->i_unwritten_work, ext4_end_io_work);
863 
864 	return &ei->vfs_inode;
865 }
866 
867 static int ext4_drop_inode(struct inode *inode)
868 {
869 	int drop = generic_drop_inode(inode);
870 
871 	trace_ext4_drop_inode(inode, drop);
872 	return drop;
873 }
874 
875 static void ext4_i_callback(struct rcu_head *head)
876 {
877 	struct inode *inode = container_of(head, struct inode, i_rcu);
878 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
879 }
880 
881 static void ext4_destroy_inode(struct inode *inode)
882 {
883 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
884 		ext4_msg(inode->i_sb, KERN_ERR,
885 			 "Inode %lu (%p): orphan list check failed!",
886 			 inode->i_ino, EXT4_I(inode));
887 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
888 				EXT4_I(inode), sizeof(struct ext4_inode_info),
889 				true);
890 		dump_stack();
891 	}
892 	call_rcu(&inode->i_rcu, ext4_i_callback);
893 }
894 
895 static void init_once(void *foo)
896 {
897 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
898 
899 	INIT_LIST_HEAD(&ei->i_orphan);
900 	init_rwsem(&ei->xattr_sem);
901 	init_rwsem(&ei->i_data_sem);
902 	inode_init_once(&ei->vfs_inode);
903 }
904 
905 static int init_inodecache(void)
906 {
907 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
908 					     sizeof(struct ext4_inode_info),
909 					     0, (SLAB_RECLAIM_ACCOUNT|
910 						SLAB_MEM_SPREAD),
911 					     init_once);
912 	if (ext4_inode_cachep == NULL)
913 		return -ENOMEM;
914 	return 0;
915 }
916 
917 static void destroy_inodecache(void)
918 {
919 	/*
920 	 * Make sure all delayed rcu free inodes are flushed before we
921 	 * destroy cache.
922 	 */
923 	rcu_barrier();
924 	kmem_cache_destroy(ext4_inode_cachep);
925 }
926 
927 void ext4_clear_inode(struct inode *inode)
928 {
929 	invalidate_inode_buffers(inode);
930 	clear_inode(inode);
931 	dquot_drop(inode);
932 	ext4_discard_preallocations(inode);
933 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
934 	ext4_es_lru_del(inode);
935 	if (EXT4_I(inode)->jinode) {
936 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
937 					       EXT4_I(inode)->jinode);
938 		jbd2_free_inode(EXT4_I(inode)->jinode);
939 		EXT4_I(inode)->jinode = NULL;
940 	}
941 }
942 
943 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
944 					u64 ino, u32 generation)
945 {
946 	struct inode *inode;
947 
948 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
949 		return ERR_PTR(-ESTALE);
950 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
951 		return ERR_PTR(-ESTALE);
952 
953 	/* iget isn't really right if the inode is currently unallocated!!
954 	 *
955 	 * ext4_read_inode will return a bad_inode if the inode had been
956 	 * deleted, so we should be safe.
957 	 *
958 	 * Currently we don't know the generation for parent directory, so
959 	 * a generation of 0 means "accept any"
960 	 */
961 	inode = ext4_iget(sb, ino);
962 	if (IS_ERR(inode))
963 		return ERR_CAST(inode);
964 	if (generation && inode->i_generation != generation) {
965 		iput(inode);
966 		return ERR_PTR(-ESTALE);
967 	}
968 
969 	return inode;
970 }
971 
972 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
973 					int fh_len, int fh_type)
974 {
975 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
976 				    ext4_nfs_get_inode);
977 }
978 
979 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
980 					int fh_len, int fh_type)
981 {
982 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
983 				    ext4_nfs_get_inode);
984 }
985 
986 /*
987  * Try to release metadata pages (indirect blocks, directories) which are
988  * mapped via the block device.  Since these pages could have journal heads
989  * which would prevent try_to_free_buffers() from freeing them, we must use
990  * jbd2 layer's try_to_free_buffers() function to release them.
991  */
992 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
993 				 gfp_t wait)
994 {
995 	journal_t *journal = EXT4_SB(sb)->s_journal;
996 
997 	WARN_ON(PageChecked(page));
998 	if (!page_has_buffers(page))
999 		return 0;
1000 	if (journal)
1001 		return jbd2_journal_try_to_free_buffers(journal, page,
1002 							wait & ~__GFP_WAIT);
1003 	return try_to_free_buffers(page);
1004 }
1005 
1006 #ifdef CONFIG_QUOTA
1007 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1008 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1009 
1010 static int ext4_write_dquot(struct dquot *dquot);
1011 static int ext4_acquire_dquot(struct dquot *dquot);
1012 static int ext4_release_dquot(struct dquot *dquot);
1013 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1014 static int ext4_write_info(struct super_block *sb, int type);
1015 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1016 			 struct path *path);
1017 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1018 				 int format_id);
1019 static int ext4_quota_off(struct super_block *sb, int type);
1020 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1021 static int ext4_quota_on_mount(struct super_block *sb, int type);
1022 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1023 			       size_t len, loff_t off);
1024 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1025 				const char *data, size_t len, loff_t off);
1026 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1027 			     unsigned int flags);
1028 static int ext4_enable_quotas(struct super_block *sb);
1029 
1030 static const struct dquot_operations ext4_quota_operations = {
1031 	.get_reserved_space = ext4_get_reserved_space,
1032 	.write_dquot	= ext4_write_dquot,
1033 	.acquire_dquot	= ext4_acquire_dquot,
1034 	.release_dquot	= ext4_release_dquot,
1035 	.mark_dirty	= ext4_mark_dquot_dirty,
1036 	.write_info	= ext4_write_info,
1037 	.alloc_dquot	= dquot_alloc,
1038 	.destroy_dquot	= dquot_destroy,
1039 };
1040 
1041 static const struct quotactl_ops ext4_qctl_operations = {
1042 	.quota_on	= ext4_quota_on,
1043 	.quota_off	= ext4_quota_off,
1044 	.quota_sync	= dquot_quota_sync,
1045 	.get_info	= dquot_get_dqinfo,
1046 	.set_info	= dquot_set_dqinfo,
1047 	.get_dqblk	= dquot_get_dqblk,
1048 	.set_dqblk	= dquot_set_dqblk
1049 };
1050 
1051 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1052 	.quota_on_meta	= ext4_quota_on_sysfile,
1053 	.quota_off	= ext4_quota_off_sysfile,
1054 	.quota_sync	= dquot_quota_sync,
1055 	.get_info	= dquot_get_dqinfo,
1056 	.set_info	= dquot_set_dqinfo,
1057 	.get_dqblk	= dquot_get_dqblk,
1058 	.set_dqblk	= dquot_set_dqblk
1059 };
1060 #endif
1061 
1062 static const struct super_operations ext4_sops = {
1063 	.alloc_inode	= ext4_alloc_inode,
1064 	.destroy_inode	= ext4_destroy_inode,
1065 	.write_inode	= ext4_write_inode,
1066 	.dirty_inode	= ext4_dirty_inode,
1067 	.drop_inode	= ext4_drop_inode,
1068 	.evict_inode	= ext4_evict_inode,
1069 	.put_super	= ext4_put_super,
1070 	.sync_fs	= ext4_sync_fs,
1071 	.freeze_fs	= ext4_freeze,
1072 	.unfreeze_fs	= ext4_unfreeze,
1073 	.statfs		= ext4_statfs,
1074 	.remount_fs	= ext4_remount,
1075 	.show_options	= ext4_show_options,
1076 #ifdef CONFIG_QUOTA
1077 	.quota_read	= ext4_quota_read,
1078 	.quota_write	= ext4_quota_write,
1079 #endif
1080 	.bdev_try_to_free_page = bdev_try_to_free_page,
1081 };
1082 
1083 static const struct super_operations ext4_nojournal_sops = {
1084 	.alloc_inode	= ext4_alloc_inode,
1085 	.destroy_inode	= ext4_destroy_inode,
1086 	.write_inode	= ext4_write_inode,
1087 	.dirty_inode	= ext4_dirty_inode,
1088 	.drop_inode	= ext4_drop_inode,
1089 	.evict_inode	= ext4_evict_inode,
1090 	.put_super	= ext4_put_super,
1091 	.statfs		= ext4_statfs,
1092 	.remount_fs	= ext4_remount,
1093 	.show_options	= ext4_show_options,
1094 #ifdef CONFIG_QUOTA
1095 	.quota_read	= ext4_quota_read,
1096 	.quota_write	= ext4_quota_write,
1097 #endif
1098 	.bdev_try_to_free_page = bdev_try_to_free_page,
1099 };
1100 
1101 static const struct export_operations ext4_export_ops = {
1102 	.fh_to_dentry = ext4_fh_to_dentry,
1103 	.fh_to_parent = ext4_fh_to_parent,
1104 	.get_parent = ext4_get_parent,
1105 };
1106 
1107 enum {
1108 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1109 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1110 	Opt_nouid32, Opt_debug, Opt_removed,
1111 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1112 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1113 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1114 	Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1115 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1116 	Opt_data_err_abort, Opt_data_err_ignore,
1117 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1118 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1119 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1120 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1121 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1122 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1123 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1124 	Opt_dioread_nolock, Opt_dioread_lock,
1125 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1126 	Opt_max_dir_size_kb,
1127 };
1128 
1129 static const match_table_t tokens = {
1130 	{Opt_bsd_df, "bsddf"},
1131 	{Opt_minix_df, "minixdf"},
1132 	{Opt_grpid, "grpid"},
1133 	{Opt_grpid, "bsdgroups"},
1134 	{Opt_nogrpid, "nogrpid"},
1135 	{Opt_nogrpid, "sysvgroups"},
1136 	{Opt_resgid, "resgid=%u"},
1137 	{Opt_resuid, "resuid=%u"},
1138 	{Opt_sb, "sb=%u"},
1139 	{Opt_err_cont, "errors=continue"},
1140 	{Opt_err_panic, "errors=panic"},
1141 	{Opt_err_ro, "errors=remount-ro"},
1142 	{Opt_nouid32, "nouid32"},
1143 	{Opt_debug, "debug"},
1144 	{Opt_removed, "oldalloc"},
1145 	{Opt_removed, "orlov"},
1146 	{Opt_user_xattr, "user_xattr"},
1147 	{Opt_nouser_xattr, "nouser_xattr"},
1148 	{Opt_acl, "acl"},
1149 	{Opt_noacl, "noacl"},
1150 	{Opt_noload, "norecovery"},
1151 	{Opt_noload, "noload"},
1152 	{Opt_removed, "nobh"},
1153 	{Opt_removed, "bh"},
1154 	{Opt_commit, "commit=%u"},
1155 	{Opt_min_batch_time, "min_batch_time=%u"},
1156 	{Opt_max_batch_time, "max_batch_time=%u"},
1157 	{Opt_journal_dev, "journal_dev=%u"},
1158 	{Opt_journal_checksum, "journal_checksum"},
1159 	{Opt_journal_async_commit, "journal_async_commit"},
1160 	{Opt_abort, "abort"},
1161 	{Opt_data_journal, "data=journal"},
1162 	{Opt_data_ordered, "data=ordered"},
1163 	{Opt_data_writeback, "data=writeback"},
1164 	{Opt_data_err_abort, "data_err=abort"},
1165 	{Opt_data_err_ignore, "data_err=ignore"},
1166 	{Opt_offusrjquota, "usrjquota="},
1167 	{Opt_usrjquota, "usrjquota=%s"},
1168 	{Opt_offgrpjquota, "grpjquota="},
1169 	{Opt_grpjquota, "grpjquota=%s"},
1170 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1171 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1172 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1173 	{Opt_grpquota, "grpquota"},
1174 	{Opt_noquota, "noquota"},
1175 	{Opt_quota, "quota"},
1176 	{Opt_usrquota, "usrquota"},
1177 	{Opt_barrier, "barrier=%u"},
1178 	{Opt_barrier, "barrier"},
1179 	{Opt_nobarrier, "nobarrier"},
1180 	{Opt_i_version, "i_version"},
1181 	{Opt_stripe, "stripe=%u"},
1182 	{Opt_delalloc, "delalloc"},
1183 	{Opt_nodelalloc, "nodelalloc"},
1184 	{Opt_removed, "mblk_io_submit"},
1185 	{Opt_removed, "nomblk_io_submit"},
1186 	{Opt_block_validity, "block_validity"},
1187 	{Opt_noblock_validity, "noblock_validity"},
1188 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1189 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1190 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1191 	{Opt_auto_da_alloc, "auto_da_alloc"},
1192 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1193 	{Opt_dioread_nolock, "dioread_nolock"},
1194 	{Opt_dioread_lock, "dioread_lock"},
1195 	{Opt_discard, "discard"},
1196 	{Opt_nodiscard, "nodiscard"},
1197 	{Opt_init_itable, "init_itable=%u"},
1198 	{Opt_init_itable, "init_itable"},
1199 	{Opt_noinit_itable, "noinit_itable"},
1200 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1201 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1202 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1203 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1204 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1205 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1206 	{Opt_err, NULL},
1207 };
1208 
1209 static ext4_fsblk_t get_sb_block(void **data)
1210 {
1211 	ext4_fsblk_t	sb_block;
1212 	char		*options = (char *) *data;
1213 
1214 	if (!options || strncmp(options, "sb=", 3) != 0)
1215 		return 1;	/* Default location */
1216 
1217 	options += 3;
1218 	/* TODO: use simple_strtoll with >32bit ext4 */
1219 	sb_block = simple_strtoul(options, &options, 0);
1220 	if (*options && *options != ',') {
1221 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1222 		       (char *) *data);
1223 		return 1;
1224 	}
1225 	if (*options == ',')
1226 		options++;
1227 	*data = (void *) options;
1228 
1229 	return sb_block;
1230 }
1231 
1232 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1233 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1234 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1235 
1236 #ifdef CONFIG_QUOTA
1237 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1238 {
1239 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1240 	char *qname;
1241 	int ret = -1;
1242 
1243 	if (sb_any_quota_loaded(sb) &&
1244 		!sbi->s_qf_names[qtype]) {
1245 		ext4_msg(sb, KERN_ERR,
1246 			"Cannot change journaled "
1247 			"quota options when quota turned on");
1248 		return -1;
1249 	}
1250 	qname = match_strdup(args);
1251 	if (!qname) {
1252 		ext4_msg(sb, KERN_ERR,
1253 			"Not enough memory for storing quotafile name");
1254 		return -1;
1255 	}
1256 	if (sbi->s_qf_names[qtype]) {
1257 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1258 			ret = 1;
1259 		else
1260 			ext4_msg(sb, KERN_ERR,
1261 				 "%s quota file already specified",
1262 				 QTYPE2NAME(qtype));
1263 		goto errout;
1264 	}
1265 	if (strchr(qname, '/')) {
1266 		ext4_msg(sb, KERN_ERR,
1267 			"quotafile must be on filesystem root");
1268 		goto errout;
1269 	}
1270 	sbi->s_qf_names[qtype] = qname;
1271 	set_opt(sb, QUOTA);
1272 	return 1;
1273 errout:
1274 	kfree(qname);
1275 	return ret;
1276 }
1277 
1278 static int clear_qf_name(struct super_block *sb, int qtype)
1279 {
1280 
1281 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1282 
1283 	if (sb_any_quota_loaded(sb) &&
1284 		sbi->s_qf_names[qtype]) {
1285 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1286 			" when quota turned on");
1287 		return -1;
1288 	}
1289 	kfree(sbi->s_qf_names[qtype]);
1290 	sbi->s_qf_names[qtype] = NULL;
1291 	return 1;
1292 }
1293 #endif
1294 
1295 #define MOPT_SET	0x0001
1296 #define MOPT_CLEAR	0x0002
1297 #define MOPT_NOSUPPORT	0x0004
1298 #define MOPT_EXPLICIT	0x0008
1299 #define MOPT_CLEAR_ERR	0x0010
1300 #define MOPT_GTE0	0x0020
1301 #ifdef CONFIG_QUOTA
1302 #define MOPT_Q		0
1303 #define MOPT_QFMT	0x0040
1304 #else
1305 #define MOPT_Q		MOPT_NOSUPPORT
1306 #define MOPT_QFMT	MOPT_NOSUPPORT
1307 #endif
1308 #define MOPT_DATAJ	0x0080
1309 #define MOPT_NO_EXT2	0x0100
1310 #define MOPT_NO_EXT3	0x0200
1311 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1312 
1313 static const struct mount_opts {
1314 	int	token;
1315 	int	mount_opt;
1316 	int	flags;
1317 } ext4_mount_opts[] = {
1318 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1319 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1320 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1321 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1322 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1323 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1324 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1325 	 MOPT_EXT4_ONLY | MOPT_SET},
1326 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1327 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1328 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1329 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1330 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1331 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1332 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1333 	 MOPT_EXT4_ONLY | MOPT_CLEAR | MOPT_EXPLICIT},
1334 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1335 	 MOPT_EXT4_ONLY | MOPT_SET},
1336 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1337 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1338 	 MOPT_EXT4_ONLY | MOPT_SET},
1339 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1340 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1341 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1342 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1343 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1344 	 MOPT_NO_EXT2 | MOPT_SET},
1345 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1346 	 MOPT_NO_EXT2 | MOPT_CLEAR},
1347 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1348 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1349 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1350 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1351 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1352 	{Opt_commit, 0, MOPT_GTE0},
1353 	{Opt_max_batch_time, 0, MOPT_GTE0},
1354 	{Opt_min_batch_time, 0, MOPT_GTE0},
1355 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1356 	{Opt_init_itable, 0, MOPT_GTE0},
1357 	{Opt_stripe, 0, MOPT_GTE0},
1358 	{Opt_resuid, 0, MOPT_GTE0},
1359 	{Opt_resgid, 0, MOPT_GTE0},
1360 	{Opt_journal_dev, 0, MOPT_GTE0},
1361 	{Opt_journal_ioprio, 0, MOPT_GTE0},
1362 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1363 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1364 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1365 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1366 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1367 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1368 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1369 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1370 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1371 #else
1372 	{Opt_acl, 0, MOPT_NOSUPPORT},
1373 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1374 #endif
1375 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1376 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1377 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1378 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1379 							MOPT_SET | MOPT_Q},
1380 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1381 							MOPT_SET | MOPT_Q},
1382 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1383 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1384 	{Opt_usrjquota, 0, MOPT_Q},
1385 	{Opt_grpjquota, 0, MOPT_Q},
1386 	{Opt_offusrjquota, 0, MOPT_Q},
1387 	{Opt_offgrpjquota, 0, MOPT_Q},
1388 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1389 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1390 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1391 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1392 	{Opt_err, 0, 0}
1393 };
1394 
1395 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1396 			    substring_t *args, unsigned long *journal_devnum,
1397 			    unsigned int *journal_ioprio, int is_remount)
1398 {
1399 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1400 	const struct mount_opts *m;
1401 	kuid_t uid;
1402 	kgid_t gid;
1403 	int arg = 0;
1404 
1405 #ifdef CONFIG_QUOTA
1406 	if (token == Opt_usrjquota)
1407 		return set_qf_name(sb, USRQUOTA, &args[0]);
1408 	else if (token == Opt_grpjquota)
1409 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1410 	else if (token == Opt_offusrjquota)
1411 		return clear_qf_name(sb, USRQUOTA);
1412 	else if (token == Opt_offgrpjquota)
1413 		return clear_qf_name(sb, GRPQUOTA);
1414 #endif
1415 	switch (token) {
1416 	case Opt_noacl:
1417 	case Opt_nouser_xattr:
1418 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1419 		break;
1420 	case Opt_sb:
1421 		return 1;	/* handled by get_sb_block() */
1422 	case Opt_removed:
1423 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1424 		return 1;
1425 	case Opt_abort:
1426 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1427 		return 1;
1428 	case Opt_i_version:
1429 		sb->s_flags |= MS_I_VERSION;
1430 		return 1;
1431 	}
1432 
1433 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1434 		if (token == m->token)
1435 			break;
1436 
1437 	if (m->token == Opt_err) {
1438 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1439 			 "or missing value", opt);
1440 		return -1;
1441 	}
1442 
1443 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1444 		ext4_msg(sb, KERN_ERR,
1445 			 "Mount option \"%s\" incompatible with ext2", opt);
1446 		return -1;
1447 	}
1448 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1449 		ext4_msg(sb, KERN_ERR,
1450 			 "Mount option \"%s\" incompatible with ext3", opt);
1451 		return -1;
1452 	}
1453 
1454 	if (args->from && match_int(args, &arg))
1455 		return -1;
1456 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1457 		return -1;
1458 	if (m->flags & MOPT_EXPLICIT)
1459 		set_opt2(sb, EXPLICIT_DELALLOC);
1460 	if (m->flags & MOPT_CLEAR_ERR)
1461 		clear_opt(sb, ERRORS_MASK);
1462 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1463 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1464 			 "options when quota turned on");
1465 		return -1;
1466 	}
1467 
1468 	if (m->flags & MOPT_NOSUPPORT) {
1469 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1470 	} else if (token == Opt_commit) {
1471 		if (arg == 0)
1472 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1473 		sbi->s_commit_interval = HZ * arg;
1474 	} else if (token == Opt_max_batch_time) {
1475 		if (arg == 0)
1476 			arg = EXT4_DEF_MAX_BATCH_TIME;
1477 		sbi->s_max_batch_time = arg;
1478 	} else if (token == Opt_min_batch_time) {
1479 		sbi->s_min_batch_time = arg;
1480 	} else if (token == Opt_inode_readahead_blks) {
1481 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1482 			ext4_msg(sb, KERN_ERR,
1483 				 "EXT4-fs: inode_readahead_blks must be "
1484 				 "0 or a power of 2 smaller than 2^31");
1485 			return -1;
1486 		}
1487 		sbi->s_inode_readahead_blks = arg;
1488 	} else if (token == Opt_init_itable) {
1489 		set_opt(sb, INIT_INODE_TABLE);
1490 		if (!args->from)
1491 			arg = EXT4_DEF_LI_WAIT_MULT;
1492 		sbi->s_li_wait_mult = arg;
1493 	} else if (token == Opt_max_dir_size_kb) {
1494 		sbi->s_max_dir_size_kb = arg;
1495 	} else if (token == Opt_stripe) {
1496 		sbi->s_stripe = arg;
1497 	} else if (token == Opt_resuid) {
1498 		uid = make_kuid(current_user_ns(), arg);
1499 		if (!uid_valid(uid)) {
1500 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1501 			return -1;
1502 		}
1503 		sbi->s_resuid = uid;
1504 	} else if (token == Opt_resgid) {
1505 		gid = make_kgid(current_user_ns(), arg);
1506 		if (!gid_valid(gid)) {
1507 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1508 			return -1;
1509 		}
1510 		sbi->s_resgid = gid;
1511 	} else if (token == Opt_journal_dev) {
1512 		if (is_remount) {
1513 			ext4_msg(sb, KERN_ERR,
1514 				 "Cannot specify journal on remount");
1515 			return -1;
1516 		}
1517 		*journal_devnum = arg;
1518 	} else if (token == Opt_journal_ioprio) {
1519 		if (arg > 7) {
1520 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1521 				 " (must be 0-7)");
1522 			return -1;
1523 		}
1524 		*journal_ioprio =
1525 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1526 	} else if (m->flags & MOPT_DATAJ) {
1527 		if (is_remount) {
1528 			if (!sbi->s_journal)
1529 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1530 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1531 				ext4_msg(sb, KERN_ERR,
1532 					 "Cannot change data mode on remount");
1533 				return -1;
1534 			}
1535 		} else {
1536 			clear_opt(sb, DATA_FLAGS);
1537 			sbi->s_mount_opt |= m->mount_opt;
1538 		}
1539 #ifdef CONFIG_QUOTA
1540 	} else if (m->flags & MOPT_QFMT) {
1541 		if (sb_any_quota_loaded(sb) &&
1542 		    sbi->s_jquota_fmt != m->mount_opt) {
1543 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1544 				 "quota options when quota turned on");
1545 			return -1;
1546 		}
1547 		sbi->s_jquota_fmt = m->mount_opt;
1548 #endif
1549 	} else {
1550 		if (!args->from)
1551 			arg = 1;
1552 		if (m->flags & MOPT_CLEAR)
1553 			arg = !arg;
1554 		else if (unlikely(!(m->flags & MOPT_SET))) {
1555 			ext4_msg(sb, KERN_WARNING,
1556 				 "buggy handling of option %s", opt);
1557 			WARN_ON(1);
1558 			return -1;
1559 		}
1560 		if (arg != 0)
1561 			sbi->s_mount_opt |= m->mount_opt;
1562 		else
1563 			sbi->s_mount_opt &= ~m->mount_opt;
1564 	}
1565 	return 1;
1566 }
1567 
1568 static int parse_options(char *options, struct super_block *sb,
1569 			 unsigned long *journal_devnum,
1570 			 unsigned int *journal_ioprio,
1571 			 int is_remount)
1572 {
1573 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1574 	char *p;
1575 	substring_t args[MAX_OPT_ARGS];
1576 	int token;
1577 
1578 	if (!options)
1579 		return 1;
1580 
1581 	while ((p = strsep(&options, ",")) != NULL) {
1582 		if (!*p)
1583 			continue;
1584 		/*
1585 		 * Initialize args struct so we know whether arg was
1586 		 * found; some options take optional arguments.
1587 		 */
1588 		args[0].to = args[0].from = NULL;
1589 		token = match_token(p, tokens, args);
1590 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1591 				     journal_ioprio, is_remount) < 0)
1592 			return 0;
1593 	}
1594 #ifdef CONFIG_QUOTA
1595 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1596 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1597 			clear_opt(sb, USRQUOTA);
1598 
1599 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1600 			clear_opt(sb, GRPQUOTA);
1601 
1602 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1603 			ext4_msg(sb, KERN_ERR, "old and new quota "
1604 					"format mixing");
1605 			return 0;
1606 		}
1607 
1608 		if (!sbi->s_jquota_fmt) {
1609 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1610 					"not specified");
1611 			return 0;
1612 		}
1613 	} else {
1614 		if (sbi->s_jquota_fmt) {
1615 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1616 					"specified with no journaling "
1617 					"enabled");
1618 			return 0;
1619 		}
1620 	}
1621 #endif
1622 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1623 		int blocksize =
1624 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1625 
1626 		if (blocksize < PAGE_CACHE_SIZE) {
1627 			ext4_msg(sb, KERN_ERR, "can't mount with "
1628 				 "dioread_nolock if block size != PAGE_SIZE");
1629 			return 0;
1630 		}
1631 	}
1632 	return 1;
1633 }
1634 
1635 static inline void ext4_show_quota_options(struct seq_file *seq,
1636 					   struct super_block *sb)
1637 {
1638 #if defined(CONFIG_QUOTA)
1639 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1640 
1641 	if (sbi->s_jquota_fmt) {
1642 		char *fmtname = "";
1643 
1644 		switch (sbi->s_jquota_fmt) {
1645 		case QFMT_VFS_OLD:
1646 			fmtname = "vfsold";
1647 			break;
1648 		case QFMT_VFS_V0:
1649 			fmtname = "vfsv0";
1650 			break;
1651 		case QFMT_VFS_V1:
1652 			fmtname = "vfsv1";
1653 			break;
1654 		}
1655 		seq_printf(seq, ",jqfmt=%s", fmtname);
1656 	}
1657 
1658 	if (sbi->s_qf_names[USRQUOTA])
1659 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1660 
1661 	if (sbi->s_qf_names[GRPQUOTA])
1662 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1663 
1664 	if (test_opt(sb, USRQUOTA))
1665 		seq_puts(seq, ",usrquota");
1666 
1667 	if (test_opt(sb, GRPQUOTA))
1668 		seq_puts(seq, ",grpquota");
1669 #endif
1670 }
1671 
1672 static const char *token2str(int token)
1673 {
1674 	const struct match_token *t;
1675 
1676 	for (t = tokens; t->token != Opt_err; t++)
1677 		if (t->token == token && !strchr(t->pattern, '='))
1678 			break;
1679 	return t->pattern;
1680 }
1681 
1682 /*
1683  * Show an option if
1684  *  - it's set to a non-default value OR
1685  *  - if the per-sb default is different from the global default
1686  */
1687 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1688 			      int nodefs)
1689 {
1690 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1691 	struct ext4_super_block *es = sbi->s_es;
1692 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1693 	const struct mount_opts *m;
1694 	char sep = nodefs ? '\n' : ',';
1695 
1696 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1697 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1698 
1699 	if (sbi->s_sb_block != 1)
1700 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1701 
1702 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1703 		int want_set = m->flags & MOPT_SET;
1704 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1705 		    (m->flags & MOPT_CLEAR_ERR))
1706 			continue;
1707 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1708 			continue; /* skip if same as the default */
1709 		if ((want_set &&
1710 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1711 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1712 			continue; /* select Opt_noFoo vs Opt_Foo */
1713 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1714 	}
1715 
1716 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1717 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1718 		SEQ_OPTS_PRINT("resuid=%u",
1719 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1720 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1721 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1722 		SEQ_OPTS_PRINT("resgid=%u",
1723 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1724 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1725 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1726 		SEQ_OPTS_PUTS("errors=remount-ro");
1727 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1728 		SEQ_OPTS_PUTS("errors=continue");
1729 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1730 		SEQ_OPTS_PUTS("errors=panic");
1731 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1732 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1733 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1734 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1735 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1736 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1737 	if (sb->s_flags & MS_I_VERSION)
1738 		SEQ_OPTS_PUTS("i_version");
1739 	if (nodefs || sbi->s_stripe)
1740 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1741 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1742 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1743 			SEQ_OPTS_PUTS("data=journal");
1744 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1745 			SEQ_OPTS_PUTS("data=ordered");
1746 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1747 			SEQ_OPTS_PUTS("data=writeback");
1748 	}
1749 	if (nodefs ||
1750 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1751 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1752 			       sbi->s_inode_readahead_blks);
1753 
1754 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1755 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1756 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1757 	if (nodefs || sbi->s_max_dir_size_kb)
1758 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1759 
1760 	ext4_show_quota_options(seq, sb);
1761 	return 0;
1762 }
1763 
1764 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1765 {
1766 	return _ext4_show_options(seq, root->d_sb, 0);
1767 }
1768 
1769 static int options_seq_show(struct seq_file *seq, void *offset)
1770 {
1771 	struct super_block *sb = seq->private;
1772 	int rc;
1773 
1774 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1775 	rc = _ext4_show_options(seq, sb, 1);
1776 	seq_puts(seq, "\n");
1777 	return rc;
1778 }
1779 
1780 static int options_open_fs(struct inode *inode, struct file *file)
1781 {
1782 	return single_open(file, options_seq_show, PDE(inode)->data);
1783 }
1784 
1785 static const struct file_operations ext4_seq_options_fops = {
1786 	.owner = THIS_MODULE,
1787 	.open = options_open_fs,
1788 	.read = seq_read,
1789 	.llseek = seq_lseek,
1790 	.release = single_release,
1791 };
1792 
1793 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1794 			    int read_only)
1795 {
1796 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1797 	int res = 0;
1798 
1799 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1800 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1801 			 "forcing read-only mode");
1802 		res = MS_RDONLY;
1803 	}
1804 	if (read_only)
1805 		goto done;
1806 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1807 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1808 			 "running e2fsck is recommended");
1809 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1810 		ext4_msg(sb, KERN_WARNING,
1811 			 "warning: mounting fs with errors, "
1812 			 "running e2fsck is recommended");
1813 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1814 		 le16_to_cpu(es->s_mnt_count) >=
1815 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1816 		ext4_msg(sb, KERN_WARNING,
1817 			 "warning: maximal mount count reached, "
1818 			 "running e2fsck is recommended");
1819 	else if (le32_to_cpu(es->s_checkinterval) &&
1820 		(le32_to_cpu(es->s_lastcheck) +
1821 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1822 		ext4_msg(sb, KERN_WARNING,
1823 			 "warning: checktime reached, "
1824 			 "running e2fsck is recommended");
1825 	if (!sbi->s_journal)
1826 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1827 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1828 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1829 	le16_add_cpu(&es->s_mnt_count, 1);
1830 	es->s_mtime = cpu_to_le32(get_seconds());
1831 	ext4_update_dynamic_rev(sb);
1832 	if (sbi->s_journal)
1833 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1834 
1835 	ext4_commit_super(sb, 1);
1836 done:
1837 	if (test_opt(sb, DEBUG))
1838 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1839 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1840 			sb->s_blocksize,
1841 			sbi->s_groups_count,
1842 			EXT4_BLOCKS_PER_GROUP(sb),
1843 			EXT4_INODES_PER_GROUP(sb),
1844 			sbi->s_mount_opt, sbi->s_mount_opt2);
1845 
1846 	cleancache_init_fs(sb);
1847 	return res;
1848 }
1849 
1850 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1851 {
1852 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1853 	struct flex_groups *new_groups;
1854 	int size;
1855 
1856 	if (!sbi->s_log_groups_per_flex)
1857 		return 0;
1858 
1859 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
1860 	if (size <= sbi->s_flex_groups_allocated)
1861 		return 0;
1862 
1863 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1864 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1865 	if (!new_groups) {
1866 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1867 			 size / (int) sizeof(struct flex_groups));
1868 		return -ENOMEM;
1869 	}
1870 
1871 	if (sbi->s_flex_groups) {
1872 		memcpy(new_groups, sbi->s_flex_groups,
1873 		       (sbi->s_flex_groups_allocated *
1874 			sizeof(struct flex_groups)));
1875 		ext4_kvfree(sbi->s_flex_groups);
1876 	}
1877 	sbi->s_flex_groups = new_groups;
1878 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1879 	return 0;
1880 }
1881 
1882 static int ext4_fill_flex_info(struct super_block *sb)
1883 {
1884 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1885 	struct ext4_group_desc *gdp = NULL;
1886 	ext4_group_t flex_group;
1887 	unsigned int groups_per_flex = 0;
1888 	int i, err;
1889 
1890 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1891 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1892 		sbi->s_log_groups_per_flex = 0;
1893 		return 1;
1894 	}
1895 	groups_per_flex = 1U << sbi->s_log_groups_per_flex;
1896 
1897 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1898 	if (err)
1899 		goto failed;
1900 
1901 	for (i = 0; i < sbi->s_groups_count; i++) {
1902 		gdp = ext4_get_group_desc(sb, i, NULL);
1903 
1904 		flex_group = ext4_flex_group(sbi, i);
1905 		atomic_add(ext4_free_inodes_count(sb, gdp),
1906 			   &sbi->s_flex_groups[flex_group].free_inodes);
1907 		atomic_add(ext4_free_group_clusters(sb, gdp),
1908 			   &sbi->s_flex_groups[flex_group].free_clusters);
1909 		atomic_add(ext4_used_dirs_count(sb, gdp),
1910 			   &sbi->s_flex_groups[flex_group].used_dirs);
1911 	}
1912 
1913 	return 1;
1914 failed:
1915 	return 0;
1916 }
1917 
1918 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1919 				   struct ext4_group_desc *gdp)
1920 {
1921 	int offset;
1922 	__u16 crc = 0;
1923 	__le32 le_group = cpu_to_le32(block_group);
1924 
1925 	if ((sbi->s_es->s_feature_ro_compat &
1926 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1927 		/* Use new metadata_csum algorithm */
1928 		__u16 old_csum;
1929 		__u32 csum32;
1930 
1931 		old_csum = gdp->bg_checksum;
1932 		gdp->bg_checksum = 0;
1933 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
1934 				     sizeof(le_group));
1935 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
1936 				     sbi->s_desc_size);
1937 		gdp->bg_checksum = old_csum;
1938 
1939 		crc = csum32 & 0xFFFF;
1940 		goto out;
1941 	}
1942 
1943 	/* old crc16 code */
1944 	offset = offsetof(struct ext4_group_desc, bg_checksum);
1945 
1946 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1947 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1948 	crc = crc16(crc, (__u8 *)gdp, offset);
1949 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
1950 	/* for checksum of struct ext4_group_desc do the rest...*/
1951 	if ((sbi->s_es->s_feature_incompat &
1952 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1953 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
1954 		crc = crc16(crc, (__u8 *)gdp + offset,
1955 			    le16_to_cpu(sbi->s_es->s_desc_size) -
1956 				offset);
1957 
1958 out:
1959 	return cpu_to_le16(crc);
1960 }
1961 
1962 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
1963 				struct ext4_group_desc *gdp)
1964 {
1965 	if (ext4_has_group_desc_csum(sb) &&
1966 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
1967 						      block_group, gdp)))
1968 		return 0;
1969 
1970 	return 1;
1971 }
1972 
1973 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
1974 			      struct ext4_group_desc *gdp)
1975 {
1976 	if (!ext4_has_group_desc_csum(sb))
1977 		return;
1978 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
1979 }
1980 
1981 /* Called at mount-time, super-block is locked */
1982 static int ext4_check_descriptors(struct super_block *sb,
1983 				  ext4_group_t *first_not_zeroed)
1984 {
1985 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1986 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1987 	ext4_fsblk_t last_block;
1988 	ext4_fsblk_t block_bitmap;
1989 	ext4_fsblk_t inode_bitmap;
1990 	ext4_fsblk_t inode_table;
1991 	int flexbg_flag = 0;
1992 	ext4_group_t i, grp = sbi->s_groups_count;
1993 
1994 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1995 		flexbg_flag = 1;
1996 
1997 	ext4_debug("Checking group descriptors");
1998 
1999 	for (i = 0; i < sbi->s_groups_count; i++) {
2000 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2001 
2002 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2003 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2004 		else
2005 			last_block = first_block +
2006 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2007 
2008 		if ((grp == sbi->s_groups_count) &&
2009 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2010 			grp = i;
2011 
2012 		block_bitmap = ext4_block_bitmap(sb, gdp);
2013 		if (block_bitmap < first_block || block_bitmap > last_block) {
2014 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2015 			       "Block bitmap for group %u not in group "
2016 			       "(block %llu)!", i, block_bitmap);
2017 			return 0;
2018 		}
2019 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2020 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2021 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2022 			       "Inode bitmap for group %u not in group "
2023 			       "(block %llu)!", i, inode_bitmap);
2024 			return 0;
2025 		}
2026 		inode_table = ext4_inode_table(sb, gdp);
2027 		if (inode_table < first_block ||
2028 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2029 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2030 			       "Inode table for group %u not in group "
2031 			       "(block %llu)!", i, inode_table);
2032 			return 0;
2033 		}
2034 		ext4_lock_group(sb, i);
2035 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2036 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2037 				 "Checksum for group %u failed (%u!=%u)",
2038 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2039 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2040 			if (!(sb->s_flags & MS_RDONLY)) {
2041 				ext4_unlock_group(sb, i);
2042 				return 0;
2043 			}
2044 		}
2045 		ext4_unlock_group(sb, i);
2046 		if (!flexbg_flag)
2047 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2048 	}
2049 	if (NULL != first_not_zeroed)
2050 		*first_not_zeroed = grp;
2051 
2052 	ext4_free_blocks_count_set(sbi->s_es,
2053 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2054 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2055 	return 1;
2056 }
2057 
2058 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2059  * the superblock) which were deleted from all directories, but held open by
2060  * a process at the time of a crash.  We walk the list and try to delete these
2061  * inodes at recovery time (only with a read-write filesystem).
2062  *
2063  * In order to keep the orphan inode chain consistent during traversal (in
2064  * case of crash during recovery), we link each inode into the superblock
2065  * orphan list_head and handle it the same way as an inode deletion during
2066  * normal operation (which journals the operations for us).
2067  *
2068  * We only do an iget() and an iput() on each inode, which is very safe if we
2069  * accidentally point at an in-use or already deleted inode.  The worst that
2070  * can happen in this case is that we get a "bit already cleared" message from
2071  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2072  * e2fsck was run on this filesystem, and it must have already done the orphan
2073  * inode cleanup for us, so we can safely abort without any further action.
2074  */
2075 static void ext4_orphan_cleanup(struct super_block *sb,
2076 				struct ext4_super_block *es)
2077 {
2078 	unsigned int s_flags = sb->s_flags;
2079 	int nr_orphans = 0, nr_truncates = 0;
2080 #ifdef CONFIG_QUOTA
2081 	int i;
2082 #endif
2083 	if (!es->s_last_orphan) {
2084 		jbd_debug(4, "no orphan inodes to clean up\n");
2085 		return;
2086 	}
2087 
2088 	if (bdev_read_only(sb->s_bdev)) {
2089 		ext4_msg(sb, KERN_ERR, "write access "
2090 			"unavailable, skipping orphan cleanup");
2091 		return;
2092 	}
2093 
2094 	/* Check if feature set would not allow a r/w mount */
2095 	if (!ext4_feature_set_ok(sb, 0)) {
2096 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2097 			 "unknown ROCOMPAT features");
2098 		return;
2099 	}
2100 
2101 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2102 		/* don't clear list on RO mount w/ errors */
2103 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2104 			jbd_debug(1, "Errors on filesystem, "
2105 				  "clearing orphan list.\n");
2106 			es->s_last_orphan = 0;
2107 		}
2108 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2109 		return;
2110 	}
2111 
2112 	if (s_flags & MS_RDONLY) {
2113 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2114 		sb->s_flags &= ~MS_RDONLY;
2115 	}
2116 #ifdef CONFIG_QUOTA
2117 	/* Needed for iput() to work correctly and not trash data */
2118 	sb->s_flags |= MS_ACTIVE;
2119 	/* Turn on quotas so that they are updated correctly */
2120 	for (i = 0; i < MAXQUOTAS; i++) {
2121 		if (EXT4_SB(sb)->s_qf_names[i]) {
2122 			int ret = ext4_quota_on_mount(sb, i);
2123 			if (ret < 0)
2124 				ext4_msg(sb, KERN_ERR,
2125 					"Cannot turn on journaled "
2126 					"quota: error %d", ret);
2127 		}
2128 	}
2129 #endif
2130 
2131 	while (es->s_last_orphan) {
2132 		struct inode *inode;
2133 
2134 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2135 		if (IS_ERR(inode)) {
2136 			es->s_last_orphan = 0;
2137 			break;
2138 		}
2139 
2140 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2141 		dquot_initialize(inode);
2142 		if (inode->i_nlink) {
2143 			ext4_msg(sb, KERN_DEBUG,
2144 				"%s: truncating inode %lu to %lld bytes",
2145 				__func__, inode->i_ino, inode->i_size);
2146 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2147 				  inode->i_ino, inode->i_size);
2148 			mutex_lock(&inode->i_mutex);
2149 			ext4_truncate(inode);
2150 			mutex_unlock(&inode->i_mutex);
2151 			nr_truncates++;
2152 		} else {
2153 			ext4_msg(sb, KERN_DEBUG,
2154 				"%s: deleting unreferenced inode %lu",
2155 				__func__, inode->i_ino);
2156 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2157 				  inode->i_ino);
2158 			nr_orphans++;
2159 		}
2160 		iput(inode);  /* The delete magic happens here! */
2161 	}
2162 
2163 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2164 
2165 	if (nr_orphans)
2166 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2167 		       PLURAL(nr_orphans));
2168 	if (nr_truncates)
2169 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2170 		       PLURAL(nr_truncates));
2171 #ifdef CONFIG_QUOTA
2172 	/* Turn quotas off */
2173 	for (i = 0; i < MAXQUOTAS; i++) {
2174 		if (sb_dqopt(sb)->files[i])
2175 			dquot_quota_off(sb, i);
2176 	}
2177 #endif
2178 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2179 }
2180 
2181 /*
2182  * Maximal extent format file size.
2183  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2184  * extent format containers, within a sector_t, and within i_blocks
2185  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2186  * so that won't be a limiting factor.
2187  *
2188  * However there is other limiting factor. We do store extents in the form
2189  * of starting block and length, hence the resulting length of the extent
2190  * covering maximum file size must fit into on-disk format containers as
2191  * well. Given that length is always by 1 unit bigger than max unit (because
2192  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2193  *
2194  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2195  */
2196 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2197 {
2198 	loff_t res;
2199 	loff_t upper_limit = MAX_LFS_FILESIZE;
2200 
2201 	/* small i_blocks in vfs inode? */
2202 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2203 		/*
2204 		 * CONFIG_LBDAF is not enabled implies the inode
2205 		 * i_block represent total blocks in 512 bytes
2206 		 * 32 == size of vfs inode i_blocks * 8
2207 		 */
2208 		upper_limit = (1LL << 32) - 1;
2209 
2210 		/* total blocks in file system block size */
2211 		upper_limit >>= (blkbits - 9);
2212 		upper_limit <<= blkbits;
2213 	}
2214 
2215 	/*
2216 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2217 	 * by one fs block, so ee_len can cover the extent of maximum file
2218 	 * size
2219 	 */
2220 	res = (1LL << 32) - 1;
2221 	res <<= blkbits;
2222 
2223 	/* Sanity check against vm- & vfs- imposed limits */
2224 	if (res > upper_limit)
2225 		res = upper_limit;
2226 
2227 	return res;
2228 }
2229 
2230 /*
2231  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2232  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2233  * We need to be 1 filesystem block less than the 2^48 sector limit.
2234  */
2235 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2236 {
2237 	loff_t res = EXT4_NDIR_BLOCKS;
2238 	int meta_blocks;
2239 	loff_t upper_limit;
2240 	/* This is calculated to be the largest file size for a dense, block
2241 	 * mapped file such that the file's total number of 512-byte sectors,
2242 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2243 	 *
2244 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2245 	 * number of 512-byte sectors of the file.
2246 	 */
2247 
2248 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2249 		/*
2250 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2251 		 * the inode i_block field represents total file blocks in
2252 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2253 		 */
2254 		upper_limit = (1LL << 32) - 1;
2255 
2256 		/* total blocks in file system block size */
2257 		upper_limit >>= (bits - 9);
2258 
2259 	} else {
2260 		/*
2261 		 * We use 48 bit ext4_inode i_blocks
2262 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2263 		 * represent total number of blocks in
2264 		 * file system block size
2265 		 */
2266 		upper_limit = (1LL << 48) - 1;
2267 
2268 	}
2269 
2270 	/* indirect blocks */
2271 	meta_blocks = 1;
2272 	/* double indirect blocks */
2273 	meta_blocks += 1 + (1LL << (bits-2));
2274 	/* tripple indirect blocks */
2275 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2276 
2277 	upper_limit -= meta_blocks;
2278 	upper_limit <<= bits;
2279 
2280 	res += 1LL << (bits-2);
2281 	res += 1LL << (2*(bits-2));
2282 	res += 1LL << (3*(bits-2));
2283 	res <<= bits;
2284 	if (res > upper_limit)
2285 		res = upper_limit;
2286 
2287 	if (res > MAX_LFS_FILESIZE)
2288 		res = MAX_LFS_FILESIZE;
2289 
2290 	return res;
2291 }
2292 
2293 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2294 				   ext4_fsblk_t logical_sb_block, int nr)
2295 {
2296 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2297 	ext4_group_t bg, first_meta_bg;
2298 	int has_super = 0;
2299 
2300 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2301 
2302 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2303 	    nr < first_meta_bg)
2304 		return logical_sb_block + nr + 1;
2305 	bg = sbi->s_desc_per_block * nr;
2306 	if (ext4_bg_has_super(sb, bg))
2307 		has_super = 1;
2308 
2309 	return (has_super + ext4_group_first_block_no(sb, bg));
2310 }
2311 
2312 /**
2313  * ext4_get_stripe_size: Get the stripe size.
2314  * @sbi: In memory super block info
2315  *
2316  * If we have specified it via mount option, then
2317  * use the mount option value. If the value specified at mount time is
2318  * greater than the blocks per group use the super block value.
2319  * If the super block value is greater than blocks per group return 0.
2320  * Allocator needs it be less than blocks per group.
2321  *
2322  */
2323 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2324 {
2325 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2326 	unsigned long stripe_width =
2327 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2328 	int ret;
2329 
2330 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2331 		ret = sbi->s_stripe;
2332 	else if (stripe_width <= sbi->s_blocks_per_group)
2333 		ret = stripe_width;
2334 	else if (stride <= sbi->s_blocks_per_group)
2335 		ret = stride;
2336 	else
2337 		ret = 0;
2338 
2339 	/*
2340 	 * If the stripe width is 1, this makes no sense and
2341 	 * we set it to 0 to turn off stripe handling code.
2342 	 */
2343 	if (ret <= 1)
2344 		ret = 0;
2345 
2346 	return ret;
2347 }
2348 
2349 /* sysfs supprt */
2350 
2351 struct ext4_attr {
2352 	struct attribute attr;
2353 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2354 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2355 			 const char *, size_t);
2356 	int offset;
2357 };
2358 
2359 static int parse_strtoul(const char *buf,
2360 		unsigned long max, unsigned long *value)
2361 {
2362 	char *endp;
2363 
2364 	*value = simple_strtoul(skip_spaces(buf), &endp, 0);
2365 	endp = skip_spaces(endp);
2366 	if (*endp || *value > max)
2367 		return -EINVAL;
2368 
2369 	return 0;
2370 }
2371 
2372 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2373 					      struct ext4_sb_info *sbi,
2374 					      char *buf)
2375 {
2376 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2377 		(s64) EXT4_C2B(sbi,
2378 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2379 }
2380 
2381 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2382 					 struct ext4_sb_info *sbi, char *buf)
2383 {
2384 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2385 
2386 	if (!sb->s_bdev->bd_part)
2387 		return snprintf(buf, PAGE_SIZE, "0\n");
2388 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2389 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2390 			 sbi->s_sectors_written_start) >> 1);
2391 }
2392 
2393 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2394 					  struct ext4_sb_info *sbi, char *buf)
2395 {
2396 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2397 
2398 	if (!sb->s_bdev->bd_part)
2399 		return snprintf(buf, PAGE_SIZE, "0\n");
2400 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2401 			(unsigned long long)(sbi->s_kbytes_written +
2402 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2403 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2404 }
2405 
2406 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2407 					  struct ext4_sb_info *sbi,
2408 					  const char *buf, size_t count)
2409 {
2410 	unsigned long t;
2411 
2412 	if (parse_strtoul(buf, 0x40000000, &t))
2413 		return -EINVAL;
2414 
2415 	if (t && !is_power_of_2(t))
2416 		return -EINVAL;
2417 
2418 	sbi->s_inode_readahead_blks = t;
2419 	return count;
2420 }
2421 
2422 static ssize_t sbi_ui_show(struct ext4_attr *a,
2423 			   struct ext4_sb_info *sbi, char *buf)
2424 {
2425 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2426 
2427 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2428 }
2429 
2430 static ssize_t sbi_ui_store(struct ext4_attr *a,
2431 			    struct ext4_sb_info *sbi,
2432 			    const char *buf, size_t count)
2433 {
2434 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2435 	unsigned long t;
2436 
2437 	if (parse_strtoul(buf, 0xffffffff, &t))
2438 		return -EINVAL;
2439 	*ui = t;
2440 	return count;
2441 }
2442 
2443 static ssize_t trigger_test_error(struct ext4_attr *a,
2444 				  struct ext4_sb_info *sbi,
2445 				  const char *buf, size_t count)
2446 {
2447 	int len = count;
2448 
2449 	if (!capable(CAP_SYS_ADMIN))
2450 		return -EPERM;
2451 
2452 	if (len && buf[len-1] == '\n')
2453 		len--;
2454 
2455 	if (len)
2456 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2457 	return count;
2458 }
2459 
2460 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2461 static struct ext4_attr ext4_attr_##_name = {			\
2462 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2463 	.show	= _show,					\
2464 	.store	= _store,					\
2465 	.offset = offsetof(struct ext4_sb_info, _elname),	\
2466 }
2467 #define EXT4_ATTR(name, mode, show, store) \
2468 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2469 
2470 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2471 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2472 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2473 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2474 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2475 #define ATTR_LIST(name) &ext4_attr_##name.attr
2476 
2477 EXT4_RO_ATTR(delayed_allocation_blocks);
2478 EXT4_RO_ATTR(session_write_kbytes);
2479 EXT4_RO_ATTR(lifetime_write_kbytes);
2480 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2481 		 inode_readahead_blks_store, s_inode_readahead_blks);
2482 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2483 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2484 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2485 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2486 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2487 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2488 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2489 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2490 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2491 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2492 
2493 static struct attribute *ext4_attrs[] = {
2494 	ATTR_LIST(delayed_allocation_blocks),
2495 	ATTR_LIST(session_write_kbytes),
2496 	ATTR_LIST(lifetime_write_kbytes),
2497 	ATTR_LIST(inode_readahead_blks),
2498 	ATTR_LIST(inode_goal),
2499 	ATTR_LIST(mb_stats),
2500 	ATTR_LIST(mb_max_to_scan),
2501 	ATTR_LIST(mb_min_to_scan),
2502 	ATTR_LIST(mb_order2_req),
2503 	ATTR_LIST(mb_stream_req),
2504 	ATTR_LIST(mb_group_prealloc),
2505 	ATTR_LIST(max_writeback_mb_bump),
2506 	ATTR_LIST(extent_max_zeroout_kb),
2507 	ATTR_LIST(trigger_fs_error),
2508 	NULL,
2509 };
2510 
2511 /* Features this copy of ext4 supports */
2512 EXT4_INFO_ATTR(lazy_itable_init);
2513 EXT4_INFO_ATTR(batched_discard);
2514 EXT4_INFO_ATTR(meta_bg_resize);
2515 
2516 static struct attribute *ext4_feat_attrs[] = {
2517 	ATTR_LIST(lazy_itable_init),
2518 	ATTR_LIST(batched_discard),
2519 	ATTR_LIST(meta_bg_resize),
2520 	NULL,
2521 };
2522 
2523 static ssize_t ext4_attr_show(struct kobject *kobj,
2524 			      struct attribute *attr, char *buf)
2525 {
2526 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2527 						s_kobj);
2528 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2529 
2530 	return a->show ? a->show(a, sbi, buf) : 0;
2531 }
2532 
2533 static ssize_t ext4_attr_store(struct kobject *kobj,
2534 			       struct attribute *attr,
2535 			       const char *buf, size_t len)
2536 {
2537 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2538 						s_kobj);
2539 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2540 
2541 	return a->store ? a->store(a, sbi, buf, len) : 0;
2542 }
2543 
2544 static void ext4_sb_release(struct kobject *kobj)
2545 {
2546 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2547 						s_kobj);
2548 	complete(&sbi->s_kobj_unregister);
2549 }
2550 
2551 static const struct sysfs_ops ext4_attr_ops = {
2552 	.show	= ext4_attr_show,
2553 	.store	= ext4_attr_store,
2554 };
2555 
2556 static struct kobj_type ext4_ktype = {
2557 	.default_attrs	= ext4_attrs,
2558 	.sysfs_ops	= &ext4_attr_ops,
2559 	.release	= ext4_sb_release,
2560 };
2561 
2562 static void ext4_feat_release(struct kobject *kobj)
2563 {
2564 	complete(&ext4_feat->f_kobj_unregister);
2565 }
2566 
2567 static struct kobj_type ext4_feat_ktype = {
2568 	.default_attrs	= ext4_feat_attrs,
2569 	.sysfs_ops	= &ext4_attr_ops,
2570 	.release	= ext4_feat_release,
2571 };
2572 
2573 /*
2574  * Check whether this filesystem can be mounted based on
2575  * the features present and the RDONLY/RDWR mount requested.
2576  * Returns 1 if this filesystem can be mounted as requested,
2577  * 0 if it cannot be.
2578  */
2579 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2580 {
2581 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2582 		ext4_msg(sb, KERN_ERR,
2583 			"Couldn't mount because of "
2584 			"unsupported optional features (%x)",
2585 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2586 			~EXT4_FEATURE_INCOMPAT_SUPP));
2587 		return 0;
2588 	}
2589 
2590 	if (readonly)
2591 		return 1;
2592 
2593 	/* Check that feature set is OK for a read-write mount */
2594 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2595 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2596 			 "unsupported optional features (%x)",
2597 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2598 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2599 		return 0;
2600 	}
2601 	/*
2602 	 * Large file size enabled file system can only be mounted
2603 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2604 	 */
2605 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2606 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2607 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2608 				 "cannot be mounted RDWR without "
2609 				 "CONFIG_LBDAF");
2610 			return 0;
2611 		}
2612 	}
2613 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2614 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2615 		ext4_msg(sb, KERN_ERR,
2616 			 "Can't support bigalloc feature without "
2617 			 "extents feature\n");
2618 		return 0;
2619 	}
2620 
2621 #ifndef CONFIG_QUOTA
2622 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2623 	    !readonly) {
2624 		ext4_msg(sb, KERN_ERR,
2625 			 "Filesystem with quota feature cannot be mounted RDWR "
2626 			 "without CONFIG_QUOTA");
2627 		return 0;
2628 	}
2629 #endif  /* CONFIG_QUOTA */
2630 	return 1;
2631 }
2632 
2633 /*
2634  * This function is called once a day if we have errors logged
2635  * on the file system
2636  */
2637 static void print_daily_error_info(unsigned long arg)
2638 {
2639 	struct super_block *sb = (struct super_block *) arg;
2640 	struct ext4_sb_info *sbi;
2641 	struct ext4_super_block *es;
2642 
2643 	sbi = EXT4_SB(sb);
2644 	es = sbi->s_es;
2645 
2646 	if (es->s_error_count)
2647 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2648 			 le32_to_cpu(es->s_error_count));
2649 	if (es->s_first_error_time) {
2650 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2651 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2652 		       (int) sizeof(es->s_first_error_func),
2653 		       es->s_first_error_func,
2654 		       le32_to_cpu(es->s_first_error_line));
2655 		if (es->s_first_error_ino)
2656 			printk(": inode %u",
2657 			       le32_to_cpu(es->s_first_error_ino));
2658 		if (es->s_first_error_block)
2659 			printk(": block %llu", (unsigned long long)
2660 			       le64_to_cpu(es->s_first_error_block));
2661 		printk("\n");
2662 	}
2663 	if (es->s_last_error_time) {
2664 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2665 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2666 		       (int) sizeof(es->s_last_error_func),
2667 		       es->s_last_error_func,
2668 		       le32_to_cpu(es->s_last_error_line));
2669 		if (es->s_last_error_ino)
2670 			printk(": inode %u",
2671 			       le32_to_cpu(es->s_last_error_ino));
2672 		if (es->s_last_error_block)
2673 			printk(": block %llu", (unsigned long long)
2674 			       le64_to_cpu(es->s_last_error_block));
2675 		printk("\n");
2676 	}
2677 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2678 }
2679 
2680 /* Find next suitable group and run ext4_init_inode_table */
2681 static int ext4_run_li_request(struct ext4_li_request *elr)
2682 {
2683 	struct ext4_group_desc *gdp = NULL;
2684 	ext4_group_t group, ngroups;
2685 	struct super_block *sb;
2686 	unsigned long timeout = 0;
2687 	int ret = 0;
2688 
2689 	sb = elr->lr_super;
2690 	ngroups = EXT4_SB(sb)->s_groups_count;
2691 
2692 	sb_start_write(sb);
2693 	for (group = elr->lr_next_group; group < ngroups; group++) {
2694 		gdp = ext4_get_group_desc(sb, group, NULL);
2695 		if (!gdp) {
2696 			ret = 1;
2697 			break;
2698 		}
2699 
2700 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2701 			break;
2702 	}
2703 
2704 	if (group >= ngroups)
2705 		ret = 1;
2706 
2707 	if (!ret) {
2708 		timeout = jiffies;
2709 		ret = ext4_init_inode_table(sb, group,
2710 					    elr->lr_timeout ? 0 : 1);
2711 		if (elr->lr_timeout == 0) {
2712 			timeout = (jiffies - timeout) *
2713 				  elr->lr_sbi->s_li_wait_mult;
2714 			elr->lr_timeout = timeout;
2715 		}
2716 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2717 		elr->lr_next_group = group + 1;
2718 	}
2719 	sb_end_write(sb);
2720 
2721 	return ret;
2722 }
2723 
2724 /*
2725  * Remove lr_request from the list_request and free the
2726  * request structure. Should be called with li_list_mtx held
2727  */
2728 static void ext4_remove_li_request(struct ext4_li_request *elr)
2729 {
2730 	struct ext4_sb_info *sbi;
2731 
2732 	if (!elr)
2733 		return;
2734 
2735 	sbi = elr->lr_sbi;
2736 
2737 	list_del(&elr->lr_request);
2738 	sbi->s_li_request = NULL;
2739 	kfree(elr);
2740 }
2741 
2742 static void ext4_unregister_li_request(struct super_block *sb)
2743 {
2744 	mutex_lock(&ext4_li_mtx);
2745 	if (!ext4_li_info) {
2746 		mutex_unlock(&ext4_li_mtx);
2747 		return;
2748 	}
2749 
2750 	mutex_lock(&ext4_li_info->li_list_mtx);
2751 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2752 	mutex_unlock(&ext4_li_info->li_list_mtx);
2753 	mutex_unlock(&ext4_li_mtx);
2754 }
2755 
2756 static struct task_struct *ext4_lazyinit_task;
2757 
2758 /*
2759  * This is the function where ext4lazyinit thread lives. It walks
2760  * through the request list searching for next scheduled filesystem.
2761  * When such a fs is found, run the lazy initialization request
2762  * (ext4_rn_li_request) and keep track of the time spend in this
2763  * function. Based on that time we compute next schedule time of
2764  * the request. When walking through the list is complete, compute
2765  * next waking time and put itself into sleep.
2766  */
2767 static int ext4_lazyinit_thread(void *arg)
2768 {
2769 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2770 	struct list_head *pos, *n;
2771 	struct ext4_li_request *elr;
2772 	unsigned long next_wakeup, cur;
2773 
2774 	BUG_ON(NULL == eli);
2775 
2776 cont_thread:
2777 	while (true) {
2778 		next_wakeup = MAX_JIFFY_OFFSET;
2779 
2780 		mutex_lock(&eli->li_list_mtx);
2781 		if (list_empty(&eli->li_request_list)) {
2782 			mutex_unlock(&eli->li_list_mtx);
2783 			goto exit_thread;
2784 		}
2785 
2786 		list_for_each_safe(pos, n, &eli->li_request_list) {
2787 			elr = list_entry(pos, struct ext4_li_request,
2788 					 lr_request);
2789 
2790 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2791 				if (ext4_run_li_request(elr) != 0) {
2792 					/* error, remove the lazy_init job */
2793 					ext4_remove_li_request(elr);
2794 					continue;
2795 				}
2796 			}
2797 
2798 			if (time_before(elr->lr_next_sched, next_wakeup))
2799 				next_wakeup = elr->lr_next_sched;
2800 		}
2801 		mutex_unlock(&eli->li_list_mtx);
2802 
2803 		try_to_freeze();
2804 
2805 		cur = jiffies;
2806 		if ((time_after_eq(cur, next_wakeup)) ||
2807 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2808 			cond_resched();
2809 			continue;
2810 		}
2811 
2812 		schedule_timeout_interruptible(next_wakeup - cur);
2813 
2814 		if (kthread_should_stop()) {
2815 			ext4_clear_request_list();
2816 			goto exit_thread;
2817 		}
2818 	}
2819 
2820 exit_thread:
2821 	/*
2822 	 * It looks like the request list is empty, but we need
2823 	 * to check it under the li_list_mtx lock, to prevent any
2824 	 * additions into it, and of course we should lock ext4_li_mtx
2825 	 * to atomically free the list and ext4_li_info, because at
2826 	 * this point another ext4 filesystem could be registering
2827 	 * new one.
2828 	 */
2829 	mutex_lock(&ext4_li_mtx);
2830 	mutex_lock(&eli->li_list_mtx);
2831 	if (!list_empty(&eli->li_request_list)) {
2832 		mutex_unlock(&eli->li_list_mtx);
2833 		mutex_unlock(&ext4_li_mtx);
2834 		goto cont_thread;
2835 	}
2836 	mutex_unlock(&eli->li_list_mtx);
2837 	kfree(ext4_li_info);
2838 	ext4_li_info = NULL;
2839 	mutex_unlock(&ext4_li_mtx);
2840 
2841 	return 0;
2842 }
2843 
2844 static void ext4_clear_request_list(void)
2845 {
2846 	struct list_head *pos, *n;
2847 	struct ext4_li_request *elr;
2848 
2849 	mutex_lock(&ext4_li_info->li_list_mtx);
2850 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2851 		elr = list_entry(pos, struct ext4_li_request,
2852 				 lr_request);
2853 		ext4_remove_li_request(elr);
2854 	}
2855 	mutex_unlock(&ext4_li_info->li_list_mtx);
2856 }
2857 
2858 static int ext4_run_lazyinit_thread(void)
2859 {
2860 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2861 					 ext4_li_info, "ext4lazyinit");
2862 	if (IS_ERR(ext4_lazyinit_task)) {
2863 		int err = PTR_ERR(ext4_lazyinit_task);
2864 		ext4_clear_request_list();
2865 		kfree(ext4_li_info);
2866 		ext4_li_info = NULL;
2867 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2868 				 "initialization thread\n",
2869 				 err);
2870 		return err;
2871 	}
2872 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2873 	return 0;
2874 }
2875 
2876 /*
2877  * Check whether it make sense to run itable init. thread or not.
2878  * If there is at least one uninitialized inode table, return
2879  * corresponding group number, else the loop goes through all
2880  * groups and return total number of groups.
2881  */
2882 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2883 {
2884 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2885 	struct ext4_group_desc *gdp = NULL;
2886 
2887 	for (group = 0; group < ngroups; group++) {
2888 		gdp = ext4_get_group_desc(sb, group, NULL);
2889 		if (!gdp)
2890 			continue;
2891 
2892 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2893 			break;
2894 	}
2895 
2896 	return group;
2897 }
2898 
2899 static int ext4_li_info_new(void)
2900 {
2901 	struct ext4_lazy_init *eli = NULL;
2902 
2903 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2904 	if (!eli)
2905 		return -ENOMEM;
2906 
2907 	INIT_LIST_HEAD(&eli->li_request_list);
2908 	mutex_init(&eli->li_list_mtx);
2909 
2910 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2911 
2912 	ext4_li_info = eli;
2913 
2914 	return 0;
2915 }
2916 
2917 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2918 					    ext4_group_t start)
2919 {
2920 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2921 	struct ext4_li_request *elr;
2922 	unsigned long rnd;
2923 
2924 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2925 	if (!elr)
2926 		return NULL;
2927 
2928 	elr->lr_super = sb;
2929 	elr->lr_sbi = sbi;
2930 	elr->lr_next_group = start;
2931 
2932 	/*
2933 	 * Randomize first schedule time of the request to
2934 	 * spread the inode table initialization requests
2935 	 * better.
2936 	 */
2937 	get_random_bytes(&rnd, sizeof(rnd));
2938 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
2939 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
2940 
2941 	return elr;
2942 }
2943 
2944 int ext4_register_li_request(struct super_block *sb,
2945 			     ext4_group_t first_not_zeroed)
2946 {
2947 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2948 	struct ext4_li_request *elr = NULL;
2949 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2950 	int ret = 0;
2951 
2952 	mutex_lock(&ext4_li_mtx);
2953 	if (sbi->s_li_request != NULL) {
2954 		/*
2955 		 * Reset timeout so it can be computed again, because
2956 		 * s_li_wait_mult might have changed.
2957 		 */
2958 		sbi->s_li_request->lr_timeout = 0;
2959 		goto out;
2960 	}
2961 
2962 	if (first_not_zeroed == ngroups ||
2963 	    (sb->s_flags & MS_RDONLY) ||
2964 	    !test_opt(sb, INIT_INODE_TABLE))
2965 		goto out;
2966 
2967 	elr = ext4_li_request_new(sb, first_not_zeroed);
2968 	if (!elr) {
2969 		ret = -ENOMEM;
2970 		goto out;
2971 	}
2972 
2973 	if (NULL == ext4_li_info) {
2974 		ret = ext4_li_info_new();
2975 		if (ret)
2976 			goto out;
2977 	}
2978 
2979 	mutex_lock(&ext4_li_info->li_list_mtx);
2980 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2981 	mutex_unlock(&ext4_li_info->li_list_mtx);
2982 
2983 	sbi->s_li_request = elr;
2984 	/*
2985 	 * set elr to NULL here since it has been inserted to
2986 	 * the request_list and the removal and free of it is
2987 	 * handled by ext4_clear_request_list from now on.
2988 	 */
2989 	elr = NULL;
2990 
2991 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2992 		ret = ext4_run_lazyinit_thread();
2993 		if (ret)
2994 			goto out;
2995 	}
2996 out:
2997 	mutex_unlock(&ext4_li_mtx);
2998 	if (ret)
2999 		kfree(elr);
3000 	return ret;
3001 }
3002 
3003 /*
3004  * We do not need to lock anything since this is called on
3005  * module unload.
3006  */
3007 static void ext4_destroy_lazyinit_thread(void)
3008 {
3009 	/*
3010 	 * If thread exited earlier
3011 	 * there's nothing to be done.
3012 	 */
3013 	if (!ext4_li_info || !ext4_lazyinit_task)
3014 		return;
3015 
3016 	kthread_stop(ext4_lazyinit_task);
3017 }
3018 
3019 static int set_journal_csum_feature_set(struct super_block *sb)
3020 {
3021 	int ret = 1;
3022 	int compat, incompat;
3023 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3024 
3025 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3026 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3027 		/* journal checksum v2 */
3028 		compat = 0;
3029 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3030 	} else {
3031 		/* journal checksum v1 */
3032 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3033 		incompat = 0;
3034 	}
3035 
3036 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3037 		ret = jbd2_journal_set_features(sbi->s_journal,
3038 				compat, 0,
3039 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3040 				incompat);
3041 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3042 		ret = jbd2_journal_set_features(sbi->s_journal,
3043 				compat, 0,
3044 				incompat);
3045 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3046 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3047 	} else {
3048 		jbd2_journal_clear_features(sbi->s_journal,
3049 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3050 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3051 				JBD2_FEATURE_INCOMPAT_CSUM_V2);
3052 	}
3053 
3054 	return ret;
3055 }
3056 
3057 /*
3058  * Note: calculating the overhead so we can be compatible with
3059  * historical BSD practice is quite difficult in the face of
3060  * clusters/bigalloc.  This is because multiple metadata blocks from
3061  * different block group can end up in the same allocation cluster.
3062  * Calculating the exact overhead in the face of clustered allocation
3063  * requires either O(all block bitmaps) in memory or O(number of block
3064  * groups**2) in time.  We will still calculate the superblock for
3065  * older file systems --- and if we come across with a bigalloc file
3066  * system with zero in s_overhead_clusters the estimate will be close to
3067  * correct especially for very large cluster sizes --- but for newer
3068  * file systems, it's better to calculate this figure once at mkfs
3069  * time, and store it in the superblock.  If the superblock value is
3070  * present (even for non-bigalloc file systems), we will use it.
3071  */
3072 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3073 			  char *buf)
3074 {
3075 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3076 	struct ext4_group_desc	*gdp;
3077 	ext4_fsblk_t		first_block, last_block, b;
3078 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3079 	int			s, j, count = 0;
3080 
3081 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3082 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3083 			sbi->s_itb_per_group + 2);
3084 
3085 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3086 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3087 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3088 	for (i = 0; i < ngroups; i++) {
3089 		gdp = ext4_get_group_desc(sb, i, NULL);
3090 		b = ext4_block_bitmap(sb, gdp);
3091 		if (b >= first_block && b <= last_block) {
3092 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3093 			count++;
3094 		}
3095 		b = ext4_inode_bitmap(sb, gdp);
3096 		if (b >= first_block && b <= last_block) {
3097 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3098 			count++;
3099 		}
3100 		b = ext4_inode_table(sb, gdp);
3101 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3102 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3103 				int c = EXT4_B2C(sbi, b - first_block);
3104 				ext4_set_bit(c, buf);
3105 				count++;
3106 			}
3107 		if (i != grp)
3108 			continue;
3109 		s = 0;
3110 		if (ext4_bg_has_super(sb, grp)) {
3111 			ext4_set_bit(s++, buf);
3112 			count++;
3113 		}
3114 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3115 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3116 			count++;
3117 		}
3118 	}
3119 	if (!count)
3120 		return 0;
3121 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3122 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3123 }
3124 
3125 /*
3126  * Compute the overhead and stash it in sbi->s_overhead
3127  */
3128 int ext4_calculate_overhead(struct super_block *sb)
3129 {
3130 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3131 	struct ext4_super_block *es = sbi->s_es;
3132 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3133 	ext4_fsblk_t overhead = 0;
3134 	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3135 
3136 	if (!buf)
3137 		return -ENOMEM;
3138 
3139 	/*
3140 	 * Compute the overhead (FS structures).  This is constant
3141 	 * for a given filesystem unless the number of block groups
3142 	 * changes so we cache the previous value until it does.
3143 	 */
3144 
3145 	/*
3146 	 * All of the blocks before first_data_block are overhead
3147 	 */
3148 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3149 
3150 	/*
3151 	 * Add the overhead found in each block group
3152 	 */
3153 	for (i = 0; i < ngroups; i++) {
3154 		int blks;
3155 
3156 		blks = count_overhead(sb, i, buf);
3157 		overhead += blks;
3158 		if (blks)
3159 			memset(buf, 0, PAGE_SIZE);
3160 		cond_resched();
3161 	}
3162 	/* Add the journal blocks as well */
3163 	if (sbi->s_journal)
3164 		overhead += EXT4_B2C(sbi, sbi->s_journal->j_maxlen);
3165 
3166 	sbi->s_overhead = overhead;
3167 	smp_wmb();
3168 	free_page((unsigned long) buf);
3169 	return 0;
3170 }
3171 
3172 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3173 {
3174 	char *orig_data = kstrdup(data, GFP_KERNEL);
3175 	struct buffer_head *bh;
3176 	struct ext4_super_block *es = NULL;
3177 	struct ext4_sb_info *sbi;
3178 	ext4_fsblk_t block;
3179 	ext4_fsblk_t sb_block = get_sb_block(&data);
3180 	ext4_fsblk_t logical_sb_block;
3181 	unsigned long offset = 0;
3182 	unsigned long journal_devnum = 0;
3183 	unsigned long def_mount_opts;
3184 	struct inode *root;
3185 	char *cp;
3186 	const char *descr;
3187 	int ret = -ENOMEM;
3188 	int blocksize, clustersize;
3189 	unsigned int db_count;
3190 	unsigned int i;
3191 	int needs_recovery, has_huge_files, has_bigalloc;
3192 	__u64 blocks_count;
3193 	int err = 0;
3194 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3195 	ext4_group_t first_not_zeroed;
3196 
3197 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3198 	if (!sbi)
3199 		goto out_free_orig;
3200 
3201 	sbi->s_blockgroup_lock =
3202 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3203 	if (!sbi->s_blockgroup_lock) {
3204 		kfree(sbi);
3205 		goto out_free_orig;
3206 	}
3207 	sb->s_fs_info = sbi;
3208 	sbi->s_sb = sb;
3209 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3210 	sbi->s_sb_block = sb_block;
3211 	if (sb->s_bdev->bd_part)
3212 		sbi->s_sectors_written_start =
3213 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3214 
3215 	/* Cleanup superblock name */
3216 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3217 		*cp = '!';
3218 
3219 	/* -EINVAL is default */
3220 	ret = -EINVAL;
3221 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3222 	if (!blocksize) {
3223 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3224 		goto out_fail;
3225 	}
3226 
3227 	/*
3228 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3229 	 * block sizes.  We need to calculate the offset from buffer start.
3230 	 */
3231 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3232 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3233 		offset = do_div(logical_sb_block, blocksize);
3234 	} else {
3235 		logical_sb_block = sb_block;
3236 	}
3237 
3238 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3239 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3240 		goto out_fail;
3241 	}
3242 	/*
3243 	 * Note: s_es must be initialized as soon as possible because
3244 	 *       some ext4 macro-instructions depend on its value
3245 	 */
3246 	es = (struct ext4_super_block *) (bh->b_data + offset);
3247 	sbi->s_es = es;
3248 	sb->s_magic = le16_to_cpu(es->s_magic);
3249 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3250 		goto cantfind_ext4;
3251 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3252 
3253 	/* Warn if metadata_csum and gdt_csum are both set. */
3254 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3255 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3256 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3257 		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3258 			     "redundant flags; please run fsck.");
3259 
3260 	/* Check for a known checksum algorithm */
3261 	if (!ext4_verify_csum_type(sb, es)) {
3262 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3263 			 "unknown checksum algorithm.");
3264 		silent = 1;
3265 		goto cantfind_ext4;
3266 	}
3267 
3268 	/* Load the checksum driver */
3269 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3270 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3271 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3272 		if (IS_ERR(sbi->s_chksum_driver)) {
3273 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3274 			ret = PTR_ERR(sbi->s_chksum_driver);
3275 			sbi->s_chksum_driver = NULL;
3276 			goto failed_mount;
3277 		}
3278 	}
3279 
3280 	/* Check superblock checksum */
3281 	if (!ext4_superblock_csum_verify(sb, es)) {
3282 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3283 			 "invalid superblock checksum.  Run e2fsck?");
3284 		silent = 1;
3285 		goto cantfind_ext4;
3286 	}
3287 
3288 	/* Precompute checksum seed for all metadata */
3289 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3290 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3291 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3292 					       sizeof(es->s_uuid));
3293 
3294 	/* Set defaults before we parse the mount options */
3295 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3296 	set_opt(sb, INIT_INODE_TABLE);
3297 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3298 		set_opt(sb, DEBUG);
3299 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3300 		set_opt(sb, GRPID);
3301 	if (def_mount_opts & EXT4_DEFM_UID16)
3302 		set_opt(sb, NO_UID32);
3303 	/* xattr user namespace & acls are now defaulted on */
3304 	set_opt(sb, XATTR_USER);
3305 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3306 	set_opt(sb, POSIX_ACL);
3307 #endif
3308 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3309 		set_opt(sb, JOURNAL_DATA);
3310 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3311 		set_opt(sb, ORDERED_DATA);
3312 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3313 		set_opt(sb, WRITEBACK_DATA);
3314 
3315 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3316 		set_opt(sb, ERRORS_PANIC);
3317 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3318 		set_opt(sb, ERRORS_CONT);
3319 	else
3320 		set_opt(sb, ERRORS_RO);
3321 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3322 		set_opt(sb, BLOCK_VALIDITY);
3323 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3324 		set_opt(sb, DISCARD);
3325 
3326 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3327 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3328 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3329 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3330 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3331 
3332 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3333 		set_opt(sb, BARRIER);
3334 
3335 	/*
3336 	 * enable delayed allocation by default
3337 	 * Use -o nodelalloc to turn it off
3338 	 */
3339 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3340 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3341 		set_opt(sb, DELALLOC);
3342 
3343 	/*
3344 	 * set default s_li_wait_mult for lazyinit, for the case there is
3345 	 * no mount option specified.
3346 	 */
3347 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3348 
3349 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3350 			   &journal_devnum, &journal_ioprio, 0)) {
3351 		ext4_msg(sb, KERN_WARNING,
3352 			 "failed to parse options in superblock: %s",
3353 			 sbi->s_es->s_mount_opts);
3354 	}
3355 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3356 	if (!parse_options((char *) data, sb, &journal_devnum,
3357 			   &journal_ioprio, 0))
3358 		goto failed_mount;
3359 
3360 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3361 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3362 			    "with data=journal disables delayed "
3363 			    "allocation and O_DIRECT support!\n");
3364 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3365 			ext4_msg(sb, KERN_ERR, "can't mount with "
3366 				 "both data=journal and delalloc");
3367 			goto failed_mount;
3368 		}
3369 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3370 			ext4_msg(sb, KERN_ERR, "can't mount with "
3371 				 "both data=journal and delalloc");
3372 			goto failed_mount;
3373 		}
3374 		if (test_opt(sb, DELALLOC))
3375 			clear_opt(sb, DELALLOC);
3376 	}
3377 
3378 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3379 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3380 
3381 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3382 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3383 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3384 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3385 		ext4_msg(sb, KERN_WARNING,
3386 		       "feature flags set on rev 0 fs, "
3387 		       "running e2fsck is recommended");
3388 
3389 	if (IS_EXT2_SB(sb)) {
3390 		if (ext2_feature_set_ok(sb))
3391 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3392 				 "using the ext4 subsystem");
3393 		else {
3394 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3395 				 "to feature incompatibilities");
3396 			goto failed_mount;
3397 		}
3398 	}
3399 
3400 	if (IS_EXT3_SB(sb)) {
3401 		if (ext3_feature_set_ok(sb))
3402 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3403 				 "using the ext4 subsystem");
3404 		else {
3405 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3406 				 "to feature incompatibilities");
3407 			goto failed_mount;
3408 		}
3409 	}
3410 
3411 	/*
3412 	 * Check feature flags regardless of the revision level, since we
3413 	 * previously didn't change the revision level when setting the flags,
3414 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3415 	 */
3416 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3417 		goto failed_mount;
3418 
3419 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3420 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3421 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3422 		ext4_msg(sb, KERN_ERR,
3423 		       "Unsupported filesystem blocksize %d", blocksize);
3424 		goto failed_mount;
3425 	}
3426 
3427 	if (sb->s_blocksize != blocksize) {
3428 		/* Validate the filesystem blocksize */
3429 		if (!sb_set_blocksize(sb, blocksize)) {
3430 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3431 					blocksize);
3432 			goto failed_mount;
3433 		}
3434 
3435 		brelse(bh);
3436 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3437 		offset = do_div(logical_sb_block, blocksize);
3438 		bh = sb_bread(sb, logical_sb_block);
3439 		if (!bh) {
3440 			ext4_msg(sb, KERN_ERR,
3441 			       "Can't read superblock on 2nd try");
3442 			goto failed_mount;
3443 		}
3444 		es = (struct ext4_super_block *)(bh->b_data + offset);
3445 		sbi->s_es = es;
3446 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3447 			ext4_msg(sb, KERN_ERR,
3448 			       "Magic mismatch, very weird!");
3449 			goto failed_mount;
3450 		}
3451 	}
3452 
3453 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3454 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3455 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3456 						      has_huge_files);
3457 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3458 
3459 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3460 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3461 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3462 	} else {
3463 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3464 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3465 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3466 		    (!is_power_of_2(sbi->s_inode_size)) ||
3467 		    (sbi->s_inode_size > blocksize)) {
3468 			ext4_msg(sb, KERN_ERR,
3469 			       "unsupported inode size: %d",
3470 			       sbi->s_inode_size);
3471 			goto failed_mount;
3472 		}
3473 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3474 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3475 	}
3476 
3477 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3478 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3479 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3480 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3481 		    !is_power_of_2(sbi->s_desc_size)) {
3482 			ext4_msg(sb, KERN_ERR,
3483 			       "unsupported descriptor size %lu",
3484 			       sbi->s_desc_size);
3485 			goto failed_mount;
3486 		}
3487 	} else
3488 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3489 
3490 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3491 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3492 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3493 		goto cantfind_ext4;
3494 
3495 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3496 	if (sbi->s_inodes_per_block == 0)
3497 		goto cantfind_ext4;
3498 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3499 					sbi->s_inodes_per_block;
3500 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3501 	sbi->s_sbh = bh;
3502 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3503 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3504 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3505 
3506 	for (i = 0; i < 4; i++)
3507 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3508 	sbi->s_def_hash_version = es->s_def_hash_version;
3509 	i = le32_to_cpu(es->s_flags);
3510 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3511 		sbi->s_hash_unsigned = 3;
3512 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3513 #ifdef __CHAR_UNSIGNED__
3514 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3515 		sbi->s_hash_unsigned = 3;
3516 #else
3517 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3518 #endif
3519 	}
3520 
3521 	/* Handle clustersize */
3522 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3523 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3524 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3525 	if (has_bigalloc) {
3526 		if (clustersize < blocksize) {
3527 			ext4_msg(sb, KERN_ERR,
3528 				 "cluster size (%d) smaller than "
3529 				 "block size (%d)", clustersize, blocksize);
3530 			goto failed_mount;
3531 		}
3532 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3533 			le32_to_cpu(es->s_log_block_size);
3534 		sbi->s_clusters_per_group =
3535 			le32_to_cpu(es->s_clusters_per_group);
3536 		if (sbi->s_clusters_per_group > blocksize * 8) {
3537 			ext4_msg(sb, KERN_ERR,
3538 				 "#clusters per group too big: %lu",
3539 				 sbi->s_clusters_per_group);
3540 			goto failed_mount;
3541 		}
3542 		if (sbi->s_blocks_per_group !=
3543 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3544 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3545 				 "clusters per group (%lu) inconsistent",
3546 				 sbi->s_blocks_per_group,
3547 				 sbi->s_clusters_per_group);
3548 			goto failed_mount;
3549 		}
3550 	} else {
3551 		if (clustersize != blocksize) {
3552 			ext4_warning(sb, "fragment/cluster size (%d) != "
3553 				     "block size (%d)", clustersize,
3554 				     blocksize);
3555 			clustersize = blocksize;
3556 		}
3557 		if (sbi->s_blocks_per_group > blocksize * 8) {
3558 			ext4_msg(sb, KERN_ERR,
3559 				 "#blocks per group too big: %lu",
3560 				 sbi->s_blocks_per_group);
3561 			goto failed_mount;
3562 		}
3563 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3564 		sbi->s_cluster_bits = 0;
3565 	}
3566 	sbi->s_cluster_ratio = clustersize / blocksize;
3567 
3568 	if (sbi->s_inodes_per_group > blocksize * 8) {
3569 		ext4_msg(sb, KERN_ERR,
3570 		       "#inodes per group too big: %lu",
3571 		       sbi->s_inodes_per_group);
3572 		goto failed_mount;
3573 	}
3574 
3575 	/*
3576 	 * Test whether we have more sectors than will fit in sector_t,
3577 	 * and whether the max offset is addressable by the page cache.
3578 	 */
3579 	err = generic_check_addressable(sb->s_blocksize_bits,
3580 					ext4_blocks_count(es));
3581 	if (err) {
3582 		ext4_msg(sb, KERN_ERR, "filesystem"
3583 			 " too large to mount safely on this system");
3584 		if (sizeof(sector_t) < 8)
3585 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3586 		goto failed_mount;
3587 	}
3588 
3589 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3590 		goto cantfind_ext4;
3591 
3592 	/* check blocks count against device size */
3593 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3594 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3595 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3596 		       "exceeds size of device (%llu blocks)",
3597 		       ext4_blocks_count(es), blocks_count);
3598 		goto failed_mount;
3599 	}
3600 
3601 	/*
3602 	 * It makes no sense for the first data block to be beyond the end
3603 	 * of the filesystem.
3604 	 */
3605 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3606 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3607 			 "block %u is beyond end of filesystem (%llu)",
3608 			 le32_to_cpu(es->s_first_data_block),
3609 			 ext4_blocks_count(es));
3610 		goto failed_mount;
3611 	}
3612 	blocks_count = (ext4_blocks_count(es) -
3613 			le32_to_cpu(es->s_first_data_block) +
3614 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3615 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3616 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3617 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3618 		       "(block count %llu, first data block %u, "
3619 		       "blocks per group %lu)", sbi->s_groups_count,
3620 		       ext4_blocks_count(es),
3621 		       le32_to_cpu(es->s_first_data_block),
3622 		       EXT4_BLOCKS_PER_GROUP(sb));
3623 		goto failed_mount;
3624 	}
3625 	sbi->s_groups_count = blocks_count;
3626 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3627 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3628 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3629 		   EXT4_DESC_PER_BLOCK(sb);
3630 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3631 					  sizeof(struct buffer_head *),
3632 					  GFP_KERNEL);
3633 	if (sbi->s_group_desc == NULL) {
3634 		ext4_msg(sb, KERN_ERR, "not enough memory");
3635 		ret = -ENOMEM;
3636 		goto failed_mount;
3637 	}
3638 
3639 	if (ext4_proc_root)
3640 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3641 
3642 	if (sbi->s_proc)
3643 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3644 				 &ext4_seq_options_fops, sb);
3645 
3646 	bgl_lock_init(sbi->s_blockgroup_lock);
3647 
3648 	for (i = 0; i < db_count; i++) {
3649 		block = descriptor_loc(sb, logical_sb_block, i);
3650 		sbi->s_group_desc[i] = sb_bread(sb, block);
3651 		if (!sbi->s_group_desc[i]) {
3652 			ext4_msg(sb, KERN_ERR,
3653 			       "can't read group descriptor %d", i);
3654 			db_count = i;
3655 			goto failed_mount2;
3656 		}
3657 	}
3658 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3659 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3660 		goto failed_mount2;
3661 	}
3662 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3663 		if (!ext4_fill_flex_info(sb)) {
3664 			ext4_msg(sb, KERN_ERR,
3665 			       "unable to initialize "
3666 			       "flex_bg meta info!");
3667 			goto failed_mount2;
3668 		}
3669 
3670 	sbi->s_gdb_count = db_count;
3671 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3672 	spin_lock_init(&sbi->s_next_gen_lock);
3673 
3674 	init_timer(&sbi->s_err_report);
3675 	sbi->s_err_report.function = print_daily_error_info;
3676 	sbi->s_err_report.data = (unsigned long) sb;
3677 
3678 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3679 			ext4_count_free_clusters(sb));
3680 	if (!err) {
3681 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3682 				ext4_count_free_inodes(sb));
3683 	}
3684 	if (!err) {
3685 		err = percpu_counter_init(&sbi->s_dirs_counter,
3686 				ext4_count_dirs(sb));
3687 	}
3688 	if (!err) {
3689 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3690 	}
3691 	if (err) {
3692 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3693 		goto failed_mount3;
3694 	}
3695 
3696 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3697 	sbi->s_max_writeback_mb_bump = 128;
3698 	sbi->s_extent_max_zeroout_kb = 32;
3699 
3700 	/* Register extent status tree shrinker */
3701 	ext4_es_register_shrinker(sb);
3702 
3703 	/*
3704 	 * set up enough so that it can read an inode
3705 	 */
3706 	if (!test_opt(sb, NOLOAD) &&
3707 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3708 		sb->s_op = &ext4_sops;
3709 	else
3710 		sb->s_op = &ext4_nojournal_sops;
3711 	sb->s_export_op = &ext4_export_ops;
3712 	sb->s_xattr = ext4_xattr_handlers;
3713 #ifdef CONFIG_QUOTA
3714 	sb->s_qcop = &ext4_qctl_operations;
3715 	sb->dq_op = &ext4_quota_operations;
3716 
3717 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
3718 		/* Use qctl operations for hidden quota files. */
3719 		sb->s_qcop = &ext4_qctl_sysfile_operations;
3720 	}
3721 #endif
3722 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3723 
3724 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3725 	mutex_init(&sbi->s_orphan_lock);
3726 
3727 	sb->s_root = NULL;
3728 
3729 	needs_recovery = (es->s_last_orphan != 0 ||
3730 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3731 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3732 
3733 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3734 	    !(sb->s_flags & MS_RDONLY))
3735 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3736 			goto failed_mount3;
3737 
3738 	/*
3739 	 * The first inode we look at is the journal inode.  Don't try
3740 	 * root first: it may be modified in the journal!
3741 	 */
3742 	if (!test_opt(sb, NOLOAD) &&
3743 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3744 		if (ext4_load_journal(sb, es, journal_devnum))
3745 			goto failed_mount3;
3746 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3747 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3748 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3749 		       "suppressed and not mounted read-only");
3750 		goto failed_mount_wq;
3751 	} else {
3752 		clear_opt(sb, DATA_FLAGS);
3753 		sbi->s_journal = NULL;
3754 		needs_recovery = 0;
3755 		goto no_journal;
3756 	}
3757 
3758 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3759 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3760 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3761 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3762 		goto failed_mount_wq;
3763 	}
3764 
3765 	if (!set_journal_csum_feature_set(sb)) {
3766 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3767 			 "feature set");
3768 		goto failed_mount_wq;
3769 	}
3770 
3771 	/* We have now updated the journal if required, so we can
3772 	 * validate the data journaling mode. */
3773 	switch (test_opt(sb, DATA_FLAGS)) {
3774 	case 0:
3775 		/* No mode set, assume a default based on the journal
3776 		 * capabilities: ORDERED_DATA if the journal can
3777 		 * cope, else JOURNAL_DATA
3778 		 */
3779 		if (jbd2_journal_check_available_features
3780 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3781 			set_opt(sb, ORDERED_DATA);
3782 		else
3783 			set_opt(sb, JOURNAL_DATA);
3784 		break;
3785 
3786 	case EXT4_MOUNT_ORDERED_DATA:
3787 	case EXT4_MOUNT_WRITEBACK_DATA:
3788 		if (!jbd2_journal_check_available_features
3789 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3790 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3791 			       "requested data journaling mode");
3792 			goto failed_mount_wq;
3793 		}
3794 	default:
3795 		break;
3796 	}
3797 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3798 
3799 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3800 
3801 	/*
3802 	 * The journal may have updated the bg summary counts, so we
3803 	 * need to update the global counters.
3804 	 */
3805 	percpu_counter_set(&sbi->s_freeclusters_counter,
3806 			   ext4_count_free_clusters(sb));
3807 	percpu_counter_set(&sbi->s_freeinodes_counter,
3808 			   ext4_count_free_inodes(sb));
3809 	percpu_counter_set(&sbi->s_dirs_counter,
3810 			   ext4_count_dirs(sb));
3811 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3812 
3813 no_journal:
3814 	/*
3815 	 * Get the # of file system overhead blocks from the
3816 	 * superblock if present.
3817 	 */
3818 	if (es->s_overhead_clusters)
3819 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3820 	else {
3821 		err = ext4_calculate_overhead(sb);
3822 		if (err)
3823 			goto failed_mount_wq;
3824 	}
3825 
3826 	/*
3827 	 * The maximum number of concurrent works can be high and
3828 	 * concurrency isn't really necessary.  Limit it to 1.
3829 	 */
3830 	EXT4_SB(sb)->dio_unwritten_wq =
3831 		alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3832 	if (!EXT4_SB(sb)->dio_unwritten_wq) {
3833 		printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3834 		ret = -ENOMEM;
3835 		goto failed_mount_wq;
3836 	}
3837 
3838 	/*
3839 	 * The jbd2_journal_load will have done any necessary log recovery,
3840 	 * so we can safely mount the rest of the filesystem now.
3841 	 */
3842 
3843 	root = ext4_iget(sb, EXT4_ROOT_INO);
3844 	if (IS_ERR(root)) {
3845 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3846 		ret = PTR_ERR(root);
3847 		root = NULL;
3848 		goto failed_mount4;
3849 	}
3850 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3851 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3852 		iput(root);
3853 		goto failed_mount4;
3854 	}
3855 	sb->s_root = d_make_root(root);
3856 	if (!sb->s_root) {
3857 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3858 		ret = -ENOMEM;
3859 		goto failed_mount4;
3860 	}
3861 
3862 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3863 		sb->s_flags |= MS_RDONLY;
3864 
3865 	/* determine the minimum size of new large inodes, if present */
3866 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3867 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3868 						     EXT4_GOOD_OLD_INODE_SIZE;
3869 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3870 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3871 			if (sbi->s_want_extra_isize <
3872 			    le16_to_cpu(es->s_want_extra_isize))
3873 				sbi->s_want_extra_isize =
3874 					le16_to_cpu(es->s_want_extra_isize);
3875 			if (sbi->s_want_extra_isize <
3876 			    le16_to_cpu(es->s_min_extra_isize))
3877 				sbi->s_want_extra_isize =
3878 					le16_to_cpu(es->s_min_extra_isize);
3879 		}
3880 	}
3881 	/* Check if enough inode space is available */
3882 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3883 							sbi->s_inode_size) {
3884 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3885 						       EXT4_GOOD_OLD_INODE_SIZE;
3886 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
3887 			 "available");
3888 	}
3889 
3890 	err = ext4_setup_system_zone(sb);
3891 	if (err) {
3892 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
3893 			 "zone (%d)", err);
3894 		goto failed_mount4a;
3895 	}
3896 
3897 	ext4_ext_init(sb);
3898 	err = ext4_mb_init(sb);
3899 	if (err) {
3900 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3901 			 err);
3902 		goto failed_mount5;
3903 	}
3904 
3905 	err = ext4_register_li_request(sb, first_not_zeroed);
3906 	if (err)
3907 		goto failed_mount6;
3908 
3909 	sbi->s_kobj.kset = ext4_kset;
3910 	init_completion(&sbi->s_kobj_unregister);
3911 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3912 				   "%s", sb->s_id);
3913 	if (err)
3914 		goto failed_mount7;
3915 
3916 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3917 	ext4_orphan_cleanup(sb, es);
3918 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3919 	if (needs_recovery) {
3920 		ext4_msg(sb, KERN_INFO, "recovery complete");
3921 		ext4_mark_recovery_complete(sb, es);
3922 	}
3923 	if (EXT4_SB(sb)->s_journal) {
3924 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3925 			descr = " journalled data mode";
3926 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3927 			descr = " ordered data mode";
3928 		else
3929 			descr = " writeback data mode";
3930 	} else
3931 		descr = "out journal";
3932 
3933 #ifdef CONFIG_QUOTA
3934 	/* Enable quota usage during mount. */
3935 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
3936 	    !(sb->s_flags & MS_RDONLY)) {
3937 		err = ext4_enable_quotas(sb);
3938 		if (err)
3939 			goto failed_mount8;
3940 	}
3941 #endif  /* CONFIG_QUOTA */
3942 
3943 	if (test_opt(sb, DISCARD)) {
3944 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
3945 		if (!blk_queue_discard(q))
3946 			ext4_msg(sb, KERN_WARNING,
3947 				 "mounting with \"discard\" option, but "
3948 				 "the device does not support discard");
3949 	}
3950 
3951 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3952 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3953 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3954 
3955 	if (es->s_error_count)
3956 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3957 
3958 	kfree(orig_data);
3959 	return 0;
3960 
3961 cantfind_ext4:
3962 	if (!silent)
3963 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3964 	goto failed_mount;
3965 
3966 #ifdef CONFIG_QUOTA
3967 failed_mount8:
3968 	kobject_del(&sbi->s_kobj);
3969 #endif
3970 failed_mount7:
3971 	ext4_unregister_li_request(sb);
3972 failed_mount6:
3973 	ext4_mb_release(sb);
3974 failed_mount5:
3975 	ext4_ext_release(sb);
3976 	ext4_release_system_zone(sb);
3977 failed_mount4a:
3978 	dput(sb->s_root);
3979 	sb->s_root = NULL;
3980 failed_mount4:
3981 	ext4_msg(sb, KERN_ERR, "mount failed");
3982 	destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
3983 failed_mount_wq:
3984 	if (sbi->s_journal) {
3985 		jbd2_journal_destroy(sbi->s_journal);
3986 		sbi->s_journal = NULL;
3987 	}
3988 failed_mount3:
3989 	del_timer(&sbi->s_err_report);
3990 	if (sbi->s_flex_groups)
3991 		ext4_kvfree(sbi->s_flex_groups);
3992 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
3993 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
3994 	percpu_counter_destroy(&sbi->s_dirs_counter);
3995 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
3996 	if (sbi->s_mmp_tsk)
3997 		kthread_stop(sbi->s_mmp_tsk);
3998 failed_mount2:
3999 	for (i = 0; i < db_count; i++)
4000 		brelse(sbi->s_group_desc[i]);
4001 	ext4_kvfree(sbi->s_group_desc);
4002 failed_mount:
4003 	if (sbi->s_chksum_driver)
4004 		crypto_free_shash(sbi->s_chksum_driver);
4005 	if (sbi->s_proc) {
4006 		remove_proc_entry("options", sbi->s_proc);
4007 		remove_proc_entry(sb->s_id, ext4_proc_root);
4008 	}
4009 #ifdef CONFIG_QUOTA
4010 	for (i = 0; i < MAXQUOTAS; i++)
4011 		kfree(sbi->s_qf_names[i]);
4012 #endif
4013 	ext4_blkdev_remove(sbi);
4014 	brelse(bh);
4015 out_fail:
4016 	sb->s_fs_info = NULL;
4017 	kfree(sbi->s_blockgroup_lock);
4018 	kfree(sbi);
4019 out_free_orig:
4020 	kfree(orig_data);
4021 	return err ? err : ret;
4022 }
4023 
4024 /*
4025  * Setup any per-fs journal parameters now.  We'll do this both on
4026  * initial mount, once the journal has been initialised but before we've
4027  * done any recovery; and again on any subsequent remount.
4028  */
4029 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4030 {
4031 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4032 
4033 	journal->j_commit_interval = sbi->s_commit_interval;
4034 	journal->j_min_batch_time = sbi->s_min_batch_time;
4035 	journal->j_max_batch_time = sbi->s_max_batch_time;
4036 
4037 	write_lock(&journal->j_state_lock);
4038 	if (test_opt(sb, BARRIER))
4039 		journal->j_flags |= JBD2_BARRIER;
4040 	else
4041 		journal->j_flags &= ~JBD2_BARRIER;
4042 	if (test_opt(sb, DATA_ERR_ABORT))
4043 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4044 	else
4045 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4046 	write_unlock(&journal->j_state_lock);
4047 }
4048 
4049 static journal_t *ext4_get_journal(struct super_block *sb,
4050 				   unsigned int journal_inum)
4051 {
4052 	struct inode *journal_inode;
4053 	journal_t *journal;
4054 
4055 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4056 
4057 	/* First, test for the existence of a valid inode on disk.  Bad
4058 	 * things happen if we iget() an unused inode, as the subsequent
4059 	 * iput() will try to delete it. */
4060 
4061 	journal_inode = ext4_iget(sb, journal_inum);
4062 	if (IS_ERR(journal_inode)) {
4063 		ext4_msg(sb, KERN_ERR, "no journal found");
4064 		return NULL;
4065 	}
4066 	if (!journal_inode->i_nlink) {
4067 		make_bad_inode(journal_inode);
4068 		iput(journal_inode);
4069 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4070 		return NULL;
4071 	}
4072 
4073 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4074 		  journal_inode, journal_inode->i_size);
4075 	if (!S_ISREG(journal_inode->i_mode)) {
4076 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4077 		iput(journal_inode);
4078 		return NULL;
4079 	}
4080 
4081 	journal = jbd2_journal_init_inode(journal_inode);
4082 	if (!journal) {
4083 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4084 		iput(journal_inode);
4085 		return NULL;
4086 	}
4087 	journal->j_private = sb;
4088 	ext4_init_journal_params(sb, journal);
4089 	return journal;
4090 }
4091 
4092 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4093 				       dev_t j_dev)
4094 {
4095 	struct buffer_head *bh;
4096 	journal_t *journal;
4097 	ext4_fsblk_t start;
4098 	ext4_fsblk_t len;
4099 	int hblock, blocksize;
4100 	ext4_fsblk_t sb_block;
4101 	unsigned long offset;
4102 	struct ext4_super_block *es;
4103 	struct block_device *bdev;
4104 
4105 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4106 
4107 	bdev = ext4_blkdev_get(j_dev, sb);
4108 	if (bdev == NULL)
4109 		return NULL;
4110 
4111 	blocksize = sb->s_blocksize;
4112 	hblock = bdev_logical_block_size(bdev);
4113 	if (blocksize < hblock) {
4114 		ext4_msg(sb, KERN_ERR,
4115 			"blocksize too small for journal device");
4116 		goto out_bdev;
4117 	}
4118 
4119 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4120 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4121 	set_blocksize(bdev, blocksize);
4122 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4123 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4124 		       "external journal");
4125 		goto out_bdev;
4126 	}
4127 
4128 	es = (struct ext4_super_block *) (bh->b_data + offset);
4129 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4130 	    !(le32_to_cpu(es->s_feature_incompat) &
4131 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4132 		ext4_msg(sb, KERN_ERR, "external journal has "
4133 					"bad superblock");
4134 		brelse(bh);
4135 		goto out_bdev;
4136 	}
4137 
4138 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4139 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4140 		brelse(bh);
4141 		goto out_bdev;
4142 	}
4143 
4144 	len = ext4_blocks_count(es);
4145 	start = sb_block + 1;
4146 	brelse(bh);	/* we're done with the superblock */
4147 
4148 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4149 					start, len, blocksize);
4150 	if (!journal) {
4151 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4152 		goto out_bdev;
4153 	}
4154 	journal->j_private = sb;
4155 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
4156 	wait_on_buffer(journal->j_sb_buffer);
4157 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4158 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4159 		goto out_journal;
4160 	}
4161 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4162 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4163 					"user (unsupported) - %d",
4164 			be32_to_cpu(journal->j_superblock->s_nr_users));
4165 		goto out_journal;
4166 	}
4167 	EXT4_SB(sb)->journal_bdev = bdev;
4168 	ext4_init_journal_params(sb, journal);
4169 	return journal;
4170 
4171 out_journal:
4172 	jbd2_journal_destroy(journal);
4173 out_bdev:
4174 	ext4_blkdev_put(bdev);
4175 	return NULL;
4176 }
4177 
4178 static int ext4_load_journal(struct super_block *sb,
4179 			     struct ext4_super_block *es,
4180 			     unsigned long journal_devnum)
4181 {
4182 	journal_t *journal;
4183 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4184 	dev_t journal_dev;
4185 	int err = 0;
4186 	int really_read_only;
4187 
4188 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4189 
4190 	if (journal_devnum &&
4191 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4192 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4193 			"numbers have changed");
4194 		journal_dev = new_decode_dev(journal_devnum);
4195 	} else
4196 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4197 
4198 	really_read_only = bdev_read_only(sb->s_bdev);
4199 
4200 	/*
4201 	 * Are we loading a blank journal or performing recovery after a
4202 	 * crash?  For recovery, we need to check in advance whether we
4203 	 * can get read-write access to the device.
4204 	 */
4205 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4206 		if (sb->s_flags & MS_RDONLY) {
4207 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4208 					"required on readonly filesystem");
4209 			if (really_read_only) {
4210 				ext4_msg(sb, KERN_ERR, "write access "
4211 					"unavailable, cannot proceed");
4212 				return -EROFS;
4213 			}
4214 			ext4_msg(sb, KERN_INFO, "write access will "
4215 			       "be enabled during recovery");
4216 		}
4217 	}
4218 
4219 	if (journal_inum && journal_dev) {
4220 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4221 		       "and inode journals!");
4222 		return -EINVAL;
4223 	}
4224 
4225 	if (journal_inum) {
4226 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4227 			return -EINVAL;
4228 	} else {
4229 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4230 			return -EINVAL;
4231 	}
4232 
4233 	if (!(journal->j_flags & JBD2_BARRIER))
4234 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4235 
4236 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4237 		err = jbd2_journal_wipe(journal, !really_read_only);
4238 	if (!err) {
4239 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4240 		if (save)
4241 			memcpy(save, ((char *) es) +
4242 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4243 		err = jbd2_journal_load(journal);
4244 		if (save)
4245 			memcpy(((char *) es) + EXT4_S_ERR_START,
4246 			       save, EXT4_S_ERR_LEN);
4247 		kfree(save);
4248 	}
4249 
4250 	if (err) {
4251 		ext4_msg(sb, KERN_ERR, "error loading journal");
4252 		jbd2_journal_destroy(journal);
4253 		return err;
4254 	}
4255 
4256 	EXT4_SB(sb)->s_journal = journal;
4257 	ext4_clear_journal_err(sb, es);
4258 
4259 	if (!really_read_only && journal_devnum &&
4260 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4261 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4262 
4263 		/* Make sure we flush the recovery flag to disk. */
4264 		ext4_commit_super(sb, 1);
4265 	}
4266 
4267 	return 0;
4268 }
4269 
4270 static int ext4_commit_super(struct super_block *sb, int sync)
4271 {
4272 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4273 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4274 	int error = 0;
4275 
4276 	if (!sbh || block_device_ejected(sb))
4277 		return error;
4278 	if (buffer_write_io_error(sbh)) {
4279 		/*
4280 		 * Oh, dear.  A previous attempt to write the
4281 		 * superblock failed.  This could happen because the
4282 		 * USB device was yanked out.  Or it could happen to
4283 		 * be a transient write error and maybe the block will
4284 		 * be remapped.  Nothing we can do but to retry the
4285 		 * write and hope for the best.
4286 		 */
4287 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4288 		       "superblock detected");
4289 		clear_buffer_write_io_error(sbh);
4290 		set_buffer_uptodate(sbh);
4291 	}
4292 	/*
4293 	 * If the file system is mounted read-only, don't update the
4294 	 * superblock write time.  This avoids updating the superblock
4295 	 * write time when we are mounting the root file system
4296 	 * read/only but we need to replay the journal; at that point,
4297 	 * for people who are east of GMT and who make their clock
4298 	 * tick in localtime for Windows bug-for-bug compatibility,
4299 	 * the clock is set in the future, and this will cause e2fsck
4300 	 * to complain and force a full file system check.
4301 	 */
4302 	if (!(sb->s_flags & MS_RDONLY))
4303 		es->s_wtime = cpu_to_le32(get_seconds());
4304 	if (sb->s_bdev->bd_part)
4305 		es->s_kbytes_written =
4306 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4307 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4308 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4309 	else
4310 		es->s_kbytes_written =
4311 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4312 	ext4_free_blocks_count_set(es,
4313 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4314 				&EXT4_SB(sb)->s_freeclusters_counter)));
4315 	es->s_free_inodes_count =
4316 		cpu_to_le32(percpu_counter_sum_positive(
4317 				&EXT4_SB(sb)->s_freeinodes_counter));
4318 	BUFFER_TRACE(sbh, "marking dirty");
4319 	ext4_superblock_csum_set(sb);
4320 	mark_buffer_dirty(sbh);
4321 	if (sync) {
4322 		error = sync_dirty_buffer(sbh);
4323 		if (error)
4324 			return error;
4325 
4326 		error = buffer_write_io_error(sbh);
4327 		if (error) {
4328 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4329 			       "superblock");
4330 			clear_buffer_write_io_error(sbh);
4331 			set_buffer_uptodate(sbh);
4332 		}
4333 	}
4334 	return error;
4335 }
4336 
4337 /*
4338  * Have we just finished recovery?  If so, and if we are mounting (or
4339  * remounting) the filesystem readonly, then we will end up with a
4340  * consistent fs on disk.  Record that fact.
4341  */
4342 static void ext4_mark_recovery_complete(struct super_block *sb,
4343 					struct ext4_super_block *es)
4344 {
4345 	journal_t *journal = EXT4_SB(sb)->s_journal;
4346 
4347 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4348 		BUG_ON(journal != NULL);
4349 		return;
4350 	}
4351 	jbd2_journal_lock_updates(journal);
4352 	if (jbd2_journal_flush(journal) < 0)
4353 		goto out;
4354 
4355 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4356 	    sb->s_flags & MS_RDONLY) {
4357 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4358 		ext4_commit_super(sb, 1);
4359 	}
4360 
4361 out:
4362 	jbd2_journal_unlock_updates(journal);
4363 }
4364 
4365 /*
4366  * If we are mounting (or read-write remounting) a filesystem whose journal
4367  * has recorded an error from a previous lifetime, move that error to the
4368  * main filesystem now.
4369  */
4370 static void ext4_clear_journal_err(struct super_block *sb,
4371 				   struct ext4_super_block *es)
4372 {
4373 	journal_t *journal;
4374 	int j_errno;
4375 	const char *errstr;
4376 
4377 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4378 
4379 	journal = EXT4_SB(sb)->s_journal;
4380 
4381 	/*
4382 	 * Now check for any error status which may have been recorded in the
4383 	 * journal by a prior ext4_error() or ext4_abort()
4384 	 */
4385 
4386 	j_errno = jbd2_journal_errno(journal);
4387 	if (j_errno) {
4388 		char nbuf[16];
4389 
4390 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4391 		ext4_warning(sb, "Filesystem error recorded "
4392 			     "from previous mount: %s", errstr);
4393 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4394 
4395 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4396 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4397 		ext4_commit_super(sb, 1);
4398 
4399 		jbd2_journal_clear_err(journal);
4400 		jbd2_journal_update_sb_errno(journal);
4401 	}
4402 }
4403 
4404 /*
4405  * Force the running and committing transactions to commit,
4406  * and wait on the commit.
4407  */
4408 int ext4_force_commit(struct super_block *sb)
4409 {
4410 	journal_t *journal;
4411 
4412 	if (sb->s_flags & MS_RDONLY)
4413 		return 0;
4414 
4415 	journal = EXT4_SB(sb)->s_journal;
4416 	return ext4_journal_force_commit(journal);
4417 }
4418 
4419 static int ext4_sync_fs(struct super_block *sb, int wait)
4420 {
4421 	int ret = 0;
4422 	tid_t target;
4423 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4424 
4425 	trace_ext4_sync_fs(sb, wait);
4426 	flush_workqueue(sbi->dio_unwritten_wq);
4427 	/*
4428 	 * Writeback quota in non-journalled quota case - journalled quota has
4429 	 * no dirty dquots
4430 	 */
4431 	dquot_writeback_dquots(sb, -1);
4432 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4433 		if (wait)
4434 			jbd2_log_wait_commit(sbi->s_journal, target);
4435 	}
4436 	return ret;
4437 }
4438 
4439 /*
4440  * LVM calls this function before a (read-only) snapshot is created.  This
4441  * gives us a chance to flush the journal completely and mark the fs clean.
4442  *
4443  * Note that only this function cannot bring a filesystem to be in a clean
4444  * state independently. It relies on upper layer to stop all data & metadata
4445  * modifications.
4446  */
4447 static int ext4_freeze(struct super_block *sb)
4448 {
4449 	int error = 0;
4450 	journal_t *journal;
4451 
4452 	if (sb->s_flags & MS_RDONLY)
4453 		return 0;
4454 
4455 	journal = EXT4_SB(sb)->s_journal;
4456 
4457 	/* Now we set up the journal barrier. */
4458 	jbd2_journal_lock_updates(journal);
4459 
4460 	/*
4461 	 * Don't clear the needs_recovery flag if we failed to flush
4462 	 * the journal.
4463 	 */
4464 	error = jbd2_journal_flush(journal);
4465 	if (error < 0)
4466 		goto out;
4467 
4468 	/* Journal blocked and flushed, clear needs_recovery flag. */
4469 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4470 	error = ext4_commit_super(sb, 1);
4471 out:
4472 	/* we rely on upper layer to stop further updates */
4473 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4474 	return error;
4475 }
4476 
4477 /*
4478  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4479  * flag here, even though the filesystem is not technically dirty yet.
4480  */
4481 static int ext4_unfreeze(struct super_block *sb)
4482 {
4483 	if (sb->s_flags & MS_RDONLY)
4484 		return 0;
4485 
4486 	/* Reset the needs_recovery flag before the fs is unlocked. */
4487 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4488 	ext4_commit_super(sb, 1);
4489 	return 0;
4490 }
4491 
4492 /*
4493  * Structure to save mount options for ext4_remount's benefit
4494  */
4495 struct ext4_mount_options {
4496 	unsigned long s_mount_opt;
4497 	unsigned long s_mount_opt2;
4498 	kuid_t s_resuid;
4499 	kgid_t s_resgid;
4500 	unsigned long s_commit_interval;
4501 	u32 s_min_batch_time, s_max_batch_time;
4502 #ifdef CONFIG_QUOTA
4503 	int s_jquota_fmt;
4504 	char *s_qf_names[MAXQUOTAS];
4505 #endif
4506 };
4507 
4508 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4509 {
4510 	struct ext4_super_block *es;
4511 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4512 	unsigned long old_sb_flags;
4513 	struct ext4_mount_options old_opts;
4514 	int enable_quota = 0;
4515 	ext4_group_t g;
4516 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4517 	int err = 0;
4518 #ifdef CONFIG_QUOTA
4519 	int i, j;
4520 #endif
4521 	char *orig_data = kstrdup(data, GFP_KERNEL);
4522 
4523 	/* Store the original options */
4524 	old_sb_flags = sb->s_flags;
4525 	old_opts.s_mount_opt = sbi->s_mount_opt;
4526 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4527 	old_opts.s_resuid = sbi->s_resuid;
4528 	old_opts.s_resgid = sbi->s_resgid;
4529 	old_opts.s_commit_interval = sbi->s_commit_interval;
4530 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4531 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4532 #ifdef CONFIG_QUOTA
4533 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4534 	for (i = 0; i < MAXQUOTAS; i++)
4535 		if (sbi->s_qf_names[i]) {
4536 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4537 							 GFP_KERNEL);
4538 			if (!old_opts.s_qf_names[i]) {
4539 				for (j = 0; j < i; j++)
4540 					kfree(old_opts.s_qf_names[j]);
4541 				return -ENOMEM;
4542 			}
4543 		} else
4544 			old_opts.s_qf_names[i] = NULL;
4545 #endif
4546 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4547 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4548 
4549 	/*
4550 	 * Allow the "check" option to be passed as a remount option.
4551 	 */
4552 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4553 		err = -EINVAL;
4554 		goto restore_opts;
4555 	}
4556 
4557 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4558 		ext4_abort(sb, "Abort forced by user");
4559 
4560 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4561 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4562 
4563 	es = sbi->s_es;
4564 
4565 	if (sbi->s_journal) {
4566 		ext4_init_journal_params(sb, sbi->s_journal);
4567 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4568 	}
4569 
4570 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4571 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4572 			err = -EROFS;
4573 			goto restore_opts;
4574 		}
4575 
4576 		if (*flags & MS_RDONLY) {
4577 			err = dquot_suspend(sb, -1);
4578 			if (err < 0)
4579 				goto restore_opts;
4580 
4581 			/*
4582 			 * First of all, the unconditional stuff we have to do
4583 			 * to disable replay of the journal when we next remount
4584 			 */
4585 			sb->s_flags |= MS_RDONLY;
4586 
4587 			/*
4588 			 * OK, test if we are remounting a valid rw partition
4589 			 * readonly, and if so set the rdonly flag and then
4590 			 * mark the partition as valid again.
4591 			 */
4592 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4593 			    (sbi->s_mount_state & EXT4_VALID_FS))
4594 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4595 
4596 			if (sbi->s_journal)
4597 				ext4_mark_recovery_complete(sb, es);
4598 		} else {
4599 			/* Make sure we can mount this feature set readwrite */
4600 			if (!ext4_feature_set_ok(sb, 0)) {
4601 				err = -EROFS;
4602 				goto restore_opts;
4603 			}
4604 			/*
4605 			 * Make sure the group descriptor checksums
4606 			 * are sane.  If they aren't, refuse to remount r/w.
4607 			 */
4608 			for (g = 0; g < sbi->s_groups_count; g++) {
4609 				struct ext4_group_desc *gdp =
4610 					ext4_get_group_desc(sb, g, NULL);
4611 
4612 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4613 					ext4_msg(sb, KERN_ERR,
4614 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4615 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4616 					       le16_to_cpu(gdp->bg_checksum));
4617 					err = -EINVAL;
4618 					goto restore_opts;
4619 				}
4620 			}
4621 
4622 			/*
4623 			 * If we have an unprocessed orphan list hanging
4624 			 * around from a previously readonly bdev mount,
4625 			 * require a full umount/remount for now.
4626 			 */
4627 			if (es->s_last_orphan) {
4628 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4629 				       "remount RDWR because of unprocessed "
4630 				       "orphan inode list.  Please "
4631 				       "umount/remount instead");
4632 				err = -EINVAL;
4633 				goto restore_opts;
4634 			}
4635 
4636 			/*
4637 			 * Mounting a RDONLY partition read-write, so reread
4638 			 * and store the current valid flag.  (It may have
4639 			 * been changed by e2fsck since we originally mounted
4640 			 * the partition.)
4641 			 */
4642 			if (sbi->s_journal)
4643 				ext4_clear_journal_err(sb, es);
4644 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4645 			if (!ext4_setup_super(sb, es, 0))
4646 				sb->s_flags &= ~MS_RDONLY;
4647 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4648 						     EXT4_FEATURE_INCOMPAT_MMP))
4649 				if (ext4_multi_mount_protect(sb,
4650 						le64_to_cpu(es->s_mmp_block))) {
4651 					err = -EROFS;
4652 					goto restore_opts;
4653 				}
4654 			enable_quota = 1;
4655 		}
4656 	}
4657 
4658 	/*
4659 	 * Reinitialize lazy itable initialization thread based on
4660 	 * current settings
4661 	 */
4662 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4663 		ext4_unregister_li_request(sb);
4664 	else {
4665 		ext4_group_t first_not_zeroed;
4666 		first_not_zeroed = ext4_has_uninit_itable(sb);
4667 		ext4_register_li_request(sb, first_not_zeroed);
4668 	}
4669 
4670 	ext4_setup_system_zone(sb);
4671 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4672 		ext4_commit_super(sb, 1);
4673 
4674 #ifdef CONFIG_QUOTA
4675 	/* Release old quota file names */
4676 	for (i = 0; i < MAXQUOTAS; i++)
4677 		kfree(old_opts.s_qf_names[i]);
4678 	if (enable_quota) {
4679 		if (sb_any_quota_suspended(sb))
4680 			dquot_resume(sb, -1);
4681 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4682 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4683 			err = ext4_enable_quotas(sb);
4684 			if (err)
4685 				goto restore_opts;
4686 		}
4687 	}
4688 #endif
4689 
4690 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4691 	kfree(orig_data);
4692 	return 0;
4693 
4694 restore_opts:
4695 	sb->s_flags = old_sb_flags;
4696 	sbi->s_mount_opt = old_opts.s_mount_opt;
4697 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4698 	sbi->s_resuid = old_opts.s_resuid;
4699 	sbi->s_resgid = old_opts.s_resgid;
4700 	sbi->s_commit_interval = old_opts.s_commit_interval;
4701 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4702 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4703 #ifdef CONFIG_QUOTA
4704 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4705 	for (i = 0; i < MAXQUOTAS; i++) {
4706 		kfree(sbi->s_qf_names[i]);
4707 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4708 	}
4709 #endif
4710 	kfree(orig_data);
4711 	return err;
4712 }
4713 
4714 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4715 {
4716 	struct super_block *sb = dentry->d_sb;
4717 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4718 	struct ext4_super_block *es = sbi->s_es;
4719 	ext4_fsblk_t overhead = 0;
4720 	u64 fsid;
4721 	s64 bfree;
4722 
4723 	if (!test_opt(sb, MINIX_DF))
4724 		overhead = sbi->s_overhead;
4725 
4726 	buf->f_type = EXT4_SUPER_MAGIC;
4727 	buf->f_bsize = sb->s_blocksize;
4728 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4729 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4730 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4731 	/* prevent underflow in case that few free space is available */
4732 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4733 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4734 	if (buf->f_bfree < ext4_r_blocks_count(es))
4735 		buf->f_bavail = 0;
4736 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4737 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4738 	buf->f_namelen = EXT4_NAME_LEN;
4739 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4740 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4741 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4742 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4743 
4744 	return 0;
4745 }
4746 
4747 /* Helper function for writing quotas on sync - we need to start transaction
4748  * before quota file is locked for write. Otherwise the are possible deadlocks:
4749  * Process 1                         Process 2
4750  * ext4_create()                     quota_sync()
4751  *   jbd2_journal_start()                  write_dquot()
4752  *   dquot_initialize()                         down(dqio_mutex)
4753  *     down(dqio_mutex)                    jbd2_journal_start()
4754  *
4755  */
4756 
4757 #ifdef CONFIG_QUOTA
4758 
4759 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4760 {
4761 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4762 }
4763 
4764 static int ext4_write_dquot(struct dquot *dquot)
4765 {
4766 	int ret, err;
4767 	handle_t *handle;
4768 	struct inode *inode;
4769 
4770 	inode = dquot_to_inode(dquot);
4771 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4772 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4773 	if (IS_ERR(handle))
4774 		return PTR_ERR(handle);
4775 	ret = dquot_commit(dquot);
4776 	err = ext4_journal_stop(handle);
4777 	if (!ret)
4778 		ret = err;
4779 	return ret;
4780 }
4781 
4782 static int ext4_acquire_dquot(struct dquot *dquot)
4783 {
4784 	int ret, err;
4785 	handle_t *handle;
4786 
4787 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4788 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4789 	if (IS_ERR(handle))
4790 		return PTR_ERR(handle);
4791 	ret = dquot_acquire(dquot);
4792 	err = ext4_journal_stop(handle);
4793 	if (!ret)
4794 		ret = err;
4795 	return ret;
4796 }
4797 
4798 static int ext4_release_dquot(struct dquot *dquot)
4799 {
4800 	int ret, err;
4801 	handle_t *handle;
4802 
4803 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4804 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4805 	if (IS_ERR(handle)) {
4806 		/* Release dquot anyway to avoid endless cycle in dqput() */
4807 		dquot_release(dquot);
4808 		return PTR_ERR(handle);
4809 	}
4810 	ret = dquot_release(dquot);
4811 	err = ext4_journal_stop(handle);
4812 	if (!ret)
4813 		ret = err;
4814 	return ret;
4815 }
4816 
4817 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4818 {
4819 	/* Are we journaling quotas? */
4820 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4821 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4822 		dquot_mark_dquot_dirty(dquot);
4823 		return ext4_write_dquot(dquot);
4824 	} else {
4825 		return dquot_mark_dquot_dirty(dquot);
4826 	}
4827 }
4828 
4829 static int ext4_write_info(struct super_block *sb, int type)
4830 {
4831 	int ret, err;
4832 	handle_t *handle;
4833 
4834 	/* Data block + inode block */
4835 	handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
4836 	if (IS_ERR(handle))
4837 		return PTR_ERR(handle);
4838 	ret = dquot_commit_info(sb, type);
4839 	err = ext4_journal_stop(handle);
4840 	if (!ret)
4841 		ret = err;
4842 	return ret;
4843 }
4844 
4845 /*
4846  * Turn on quotas during mount time - we need to find
4847  * the quota file and such...
4848  */
4849 static int ext4_quota_on_mount(struct super_block *sb, int type)
4850 {
4851 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4852 					EXT4_SB(sb)->s_jquota_fmt, type);
4853 }
4854 
4855 /*
4856  * Standard function to be called on quota_on
4857  */
4858 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4859 			 struct path *path)
4860 {
4861 	int err;
4862 
4863 	if (!test_opt(sb, QUOTA))
4864 		return -EINVAL;
4865 
4866 	/* Quotafile not on the same filesystem? */
4867 	if (path->dentry->d_sb != sb)
4868 		return -EXDEV;
4869 	/* Journaling quota? */
4870 	if (EXT4_SB(sb)->s_qf_names[type]) {
4871 		/* Quotafile not in fs root? */
4872 		if (path->dentry->d_parent != sb->s_root)
4873 			ext4_msg(sb, KERN_WARNING,
4874 				"Quota file not on filesystem root. "
4875 				"Journaled quota will not work");
4876 	}
4877 
4878 	/*
4879 	 * When we journal data on quota file, we have to flush journal to see
4880 	 * all updates to the file when we bypass pagecache...
4881 	 */
4882 	if (EXT4_SB(sb)->s_journal &&
4883 	    ext4_should_journal_data(path->dentry->d_inode)) {
4884 		/*
4885 		 * We don't need to lock updates but journal_flush() could
4886 		 * otherwise be livelocked...
4887 		 */
4888 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4889 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4890 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4891 		if (err)
4892 			return err;
4893 	}
4894 
4895 	return dquot_quota_on(sb, type, format_id, path);
4896 }
4897 
4898 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
4899 			     unsigned int flags)
4900 {
4901 	int err;
4902 	struct inode *qf_inode;
4903 	unsigned long qf_inums[MAXQUOTAS] = {
4904 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4905 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4906 	};
4907 
4908 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
4909 
4910 	if (!qf_inums[type])
4911 		return -EPERM;
4912 
4913 	qf_inode = ext4_iget(sb, qf_inums[type]);
4914 	if (IS_ERR(qf_inode)) {
4915 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
4916 		return PTR_ERR(qf_inode);
4917 	}
4918 
4919 	err = dquot_enable(qf_inode, type, format_id, flags);
4920 	iput(qf_inode);
4921 
4922 	return err;
4923 }
4924 
4925 /* Enable usage tracking for all quota types. */
4926 static int ext4_enable_quotas(struct super_block *sb)
4927 {
4928 	int type, err = 0;
4929 	unsigned long qf_inums[MAXQUOTAS] = {
4930 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4931 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4932 	};
4933 
4934 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
4935 	for (type = 0; type < MAXQUOTAS; type++) {
4936 		if (qf_inums[type]) {
4937 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
4938 						DQUOT_USAGE_ENABLED);
4939 			if (err) {
4940 				ext4_warning(sb,
4941 					"Failed to enable quota tracking "
4942 					"(type=%d, err=%d). Please run "
4943 					"e2fsck to fix.", type, err);
4944 				return err;
4945 			}
4946 		}
4947 	}
4948 	return 0;
4949 }
4950 
4951 /*
4952  * quota_on function that is used when QUOTA feature is set.
4953  */
4954 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
4955 				 int format_id)
4956 {
4957 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
4958 		return -EINVAL;
4959 
4960 	/*
4961 	 * USAGE was enabled at mount time. Only need to enable LIMITS now.
4962 	 */
4963 	return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
4964 }
4965 
4966 static int ext4_quota_off(struct super_block *sb, int type)
4967 {
4968 	struct inode *inode = sb_dqopt(sb)->files[type];
4969 	handle_t *handle;
4970 
4971 	/* Force all delayed allocation blocks to be allocated.
4972 	 * Caller already holds s_umount sem */
4973 	if (test_opt(sb, DELALLOC))
4974 		sync_filesystem(sb);
4975 
4976 	if (!inode)
4977 		goto out;
4978 
4979 	/* Update modification times of quota files when userspace can
4980 	 * start looking at them */
4981 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
4982 	if (IS_ERR(handle))
4983 		goto out;
4984 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
4985 	ext4_mark_inode_dirty(handle, inode);
4986 	ext4_journal_stop(handle);
4987 
4988 out:
4989 	return dquot_quota_off(sb, type);
4990 }
4991 
4992 /*
4993  * quota_off function that is used when QUOTA feature is set.
4994  */
4995 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
4996 {
4997 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
4998 		return -EINVAL;
4999 
5000 	/* Disable only the limits. */
5001 	return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5002 }
5003 
5004 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5005  * acquiring the locks... As quota files are never truncated and quota code
5006  * itself serializes the operations (and no one else should touch the files)
5007  * we don't have to be afraid of races */
5008 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5009 			       size_t len, loff_t off)
5010 {
5011 	struct inode *inode = sb_dqopt(sb)->files[type];
5012 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5013 	int err = 0;
5014 	int offset = off & (sb->s_blocksize - 1);
5015 	int tocopy;
5016 	size_t toread;
5017 	struct buffer_head *bh;
5018 	loff_t i_size = i_size_read(inode);
5019 
5020 	if (off > i_size)
5021 		return 0;
5022 	if (off+len > i_size)
5023 		len = i_size-off;
5024 	toread = len;
5025 	while (toread > 0) {
5026 		tocopy = sb->s_blocksize - offset < toread ?
5027 				sb->s_blocksize - offset : toread;
5028 		bh = ext4_bread(NULL, inode, blk, 0, &err);
5029 		if (err)
5030 			return err;
5031 		if (!bh)	/* A hole? */
5032 			memset(data, 0, tocopy);
5033 		else
5034 			memcpy(data, bh->b_data+offset, tocopy);
5035 		brelse(bh);
5036 		offset = 0;
5037 		toread -= tocopy;
5038 		data += tocopy;
5039 		blk++;
5040 	}
5041 	return len;
5042 }
5043 
5044 /* Write to quotafile (we know the transaction is already started and has
5045  * enough credits) */
5046 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5047 				const char *data, size_t len, loff_t off)
5048 {
5049 	struct inode *inode = sb_dqopt(sb)->files[type];
5050 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5051 	int err = 0;
5052 	int offset = off & (sb->s_blocksize - 1);
5053 	struct buffer_head *bh;
5054 	handle_t *handle = journal_current_handle();
5055 
5056 	if (EXT4_SB(sb)->s_journal && !handle) {
5057 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5058 			" cancelled because transaction is not started",
5059 			(unsigned long long)off, (unsigned long long)len);
5060 		return -EIO;
5061 	}
5062 	/*
5063 	 * Since we account only one data block in transaction credits,
5064 	 * then it is impossible to cross a block boundary.
5065 	 */
5066 	if (sb->s_blocksize - offset < len) {
5067 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5068 			" cancelled because not block aligned",
5069 			(unsigned long long)off, (unsigned long long)len);
5070 		return -EIO;
5071 	}
5072 
5073 	bh = ext4_bread(handle, inode, blk, 1, &err);
5074 	if (!bh)
5075 		goto out;
5076 	err = ext4_journal_get_write_access(handle, bh);
5077 	if (err) {
5078 		brelse(bh);
5079 		goto out;
5080 	}
5081 	lock_buffer(bh);
5082 	memcpy(bh->b_data+offset, data, len);
5083 	flush_dcache_page(bh->b_page);
5084 	unlock_buffer(bh);
5085 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5086 	brelse(bh);
5087 out:
5088 	if (err)
5089 		return err;
5090 	if (inode->i_size < off + len) {
5091 		i_size_write(inode, off + len);
5092 		EXT4_I(inode)->i_disksize = inode->i_size;
5093 		ext4_mark_inode_dirty(handle, inode);
5094 	}
5095 	return len;
5096 }
5097 
5098 #endif
5099 
5100 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5101 		       const char *dev_name, void *data)
5102 {
5103 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5104 }
5105 
5106 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5107 static inline void register_as_ext2(void)
5108 {
5109 	int err = register_filesystem(&ext2_fs_type);
5110 	if (err)
5111 		printk(KERN_WARNING
5112 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5113 }
5114 
5115 static inline void unregister_as_ext2(void)
5116 {
5117 	unregister_filesystem(&ext2_fs_type);
5118 }
5119 
5120 static inline int ext2_feature_set_ok(struct super_block *sb)
5121 {
5122 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5123 		return 0;
5124 	if (sb->s_flags & MS_RDONLY)
5125 		return 1;
5126 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5127 		return 0;
5128 	return 1;
5129 }
5130 MODULE_ALIAS("ext2");
5131 #else
5132 static inline void register_as_ext2(void) { }
5133 static inline void unregister_as_ext2(void) { }
5134 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5135 #endif
5136 
5137 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5138 static inline void register_as_ext3(void)
5139 {
5140 	int err = register_filesystem(&ext3_fs_type);
5141 	if (err)
5142 		printk(KERN_WARNING
5143 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5144 }
5145 
5146 static inline void unregister_as_ext3(void)
5147 {
5148 	unregister_filesystem(&ext3_fs_type);
5149 }
5150 
5151 static inline int ext3_feature_set_ok(struct super_block *sb)
5152 {
5153 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5154 		return 0;
5155 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5156 		return 0;
5157 	if (sb->s_flags & MS_RDONLY)
5158 		return 1;
5159 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5160 		return 0;
5161 	return 1;
5162 }
5163 MODULE_ALIAS("ext3");
5164 #else
5165 static inline void register_as_ext3(void) { }
5166 static inline void unregister_as_ext3(void) { }
5167 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5168 #endif
5169 
5170 static struct file_system_type ext4_fs_type = {
5171 	.owner		= THIS_MODULE,
5172 	.name		= "ext4",
5173 	.mount		= ext4_mount,
5174 	.kill_sb	= kill_block_super,
5175 	.fs_flags	= FS_REQUIRES_DEV,
5176 };
5177 
5178 static int __init ext4_init_feat_adverts(void)
5179 {
5180 	struct ext4_features *ef;
5181 	int ret = -ENOMEM;
5182 
5183 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5184 	if (!ef)
5185 		goto out;
5186 
5187 	ef->f_kobj.kset = ext4_kset;
5188 	init_completion(&ef->f_kobj_unregister);
5189 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5190 				   "features");
5191 	if (ret) {
5192 		kfree(ef);
5193 		goto out;
5194 	}
5195 
5196 	ext4_feat = ef;
5197 	ret = 0;
5198 out:
5199 	return ret;
5200 }
5201 
5202 static void ext4_exit_feat_adverts(void)
5203 {
5204 	kobject_put(&ext4_feat->f_kobj);
5205 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5206 	kfree(ext4_feat);
5207 }
5208 
5209 /* Shared across all ext4 file systems */
5210 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5211 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5212 
5213 static int __init ext4_init_fs(void)
5214 {
5215 	int i, err;
5216 
5217 	ext4_li_info = NULL;
5218 	mutex_init(&ext4_li_mtx);
5219 
5220 	/* Build-time check for flags consistency */
5221 	ext4_check_flag_values();
5222 
5223 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5224 		mutex_init(&ext4__aio_mutex[i]);
5225 		init_waitqueue_head(&ext4__ioend_wq[i]);
5226 	}
5227 
5228 	err = ext4_init_es();
5229 	if (err)
5230 		return err;
5231 
5232 	err = ext4_init_pageio();
5233 	if (err)
5234 		goto out7;
5235 
5236 	err = ext4_init_system_zone();
5237 	if (err)
5238 		goto out6;
5239 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5240 	if (!ext4_kset) {
5241 		err = -ENOMEM;
5242 		goto out5;
5243 	}
5244 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5245 
5246 	err = ext4_init_feat_adverts();
5247 	if (err)
5248 		goto out4;
5249 
5250 	err = ext4_init_mballoc();
5251 	if (err)
5252 		goto out3;
5253 
5254 	err = ext4_init_xattr();
5255 	if (err)
5256 		goto out2;
5257 	err = init_inodecache();
5258 	if (err)
5259 		goto out1;
5260 	register_as_ext3();
5261 	register_as_ext2();
5262 	err = register_filesystem(&ext4_fs_type);
5263 	if (err)
5264 		goto out;
5265 
5266 	return 0;
5267 out:
5268 	unregister_as_ext2();
5269 	unregister_as_ext3();
5270 	destroy_inodecache();
5271 out1:
5272 	ext4_exit_xattr();
5273 out2:
5274 	ext4_exit_mballoc();
5275 out3:
5276 	ext4_exit_feat_adverts();
5277 out4:
5278 	if (ext4_proc_root)
5279 		remove_proc_entry("fs/ext4", NULL);
5280 	kset_unregister(ext4_kset);
5281 out5:
5282 	ext4_exit_system_zone();
5283 out6:
5284 	ext4_exit_pageio();
5285 out7:
5286 	ext4_exit_es();
5287 
5288 	return err;
5289 }
5290 
5291 static void __exit ext4_exit_fs(void)
5292 {
5293 	ext4_destroy_lazyinit_thread();
5294 	unregister_as_ext2();
5295 	unregister_as_ext3();
5296 	unregister_filesystem(&ext4_fs_type);
5297 	destroy_inodecache();
5298 	ext4_exit_xattr();
5299 	ext4_exit_mballoc();
5300 	ext4_exit_feat_adverts();
5301 	remove_proc_entry("fs/ext4", NULL);
5302 	kset_unregister(ext4_kset);
5303 	ext4_exit_system_zone();
5304 	ext4_exit_pageio();
5305 }
5306 
5307 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5308 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5309 MODULE_LICENSE("GPL");
5310 module_init(ext4_init_fs)
5311 module_exit(ext4_exit_fs)
5312