xref: /openbmc/linux/fs/ext4/super.c (revision f7777dcc)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/jbd2.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/parser.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/proc_fs.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/cleancache.h>
42 #include <asm/uaccess.h>
43 
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46 
47 #include "ext4.h"
48 #include "ext4_extents.h"	/* Needed for trace points definition */
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/ext4.h>
56 
57 static struct proc_dir_entry *ext4_proc_root;
58 static struct kset *ext4_kset;
59 static struct ext4_lazy_init *ext4_li_info;
60 static struct mutex ext4_li_mtx;
61 static struct ext4_features *ext4_feat;
62 
63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
64 			     unsigned long journal_devnum);
65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
66 static int ext4_commit_super(struct super_block *sb, int sync);
67 static void ext4_mark_recovery_complete(struct super_block *sb,
68 					struct ext4_super_block *es);
69 static void ext4_clear_journal_err(struct super_block *sb,
70 				   struct ext4_super_block *es);
71 static int ext4_sync_fs(struct super_block *sb, int wait);
72 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait);
73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
75 static int ext4_unfreeze(struct super_block *sb);
76 static int ext4_freeze(struct super_block *sb);
77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
78 		       const char *dev_name, void *data);
79 static inline int ext2_feature_set_ok(struct super_block *sb);
80 static inline int ext3_feature_set_ok(struct super_block *sb);
81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
86 
87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
88 static struct file_system_type ext2_fs_type = {
89 	.owner		= THIS_MODULE,
90 	.name		= "ext2",
91 	.mount		= ext4_mount,
92 	.kill_sb	= kill_block_super,
93 	.fs_flags	= FS_REQUIRES_DEV,
94 };
95 MODULE_ALIAS_FS("ext2");
96 MODULE_ALIAS("ext2");
97 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
98 #else
99 #define IS_EXT2_SB(sb) (0)
100 #endif
101 
102 
103 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
104 static struct file_system_type ext3_fs_type = {
105 	.owner		= THIS_MODULE,
106 	.name		= "ext3",
107 	.mount		= ext4_mount,
108 	.kill_sb	= kill_block_super,
109 	.fs_flags	= FS_REQUIRES_DEV,
110 };
111 MODULE_ALIAS_FS("ext3");
112 MODULE_ALIAS("ext3");
113 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
114 #else
115 #define IS_EXT3_SB(sb) (0)
116 #endif
117 
118 static int ext4_verify_csum_type(struct super_block *sb,
119 				 struct ext4_super_block *es)
120 {
121 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
122 					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
123 		return 1;
124 
125 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
126 }
127 
128 static __le32 ext4_superblock_csum(struct super_block *sb,
129 				   struct ext4_super_block *es)
130 {
131 	struct ext4_sb_info *sbi = EXT4_SB(sb);
132 	int offset = offsetof(struct ext4_super_block, s_checksum);
133 	__u32 csum;
134 
135 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
136 
137 	return cpu_to_le32(csum);
138 }
139 
140 int ext4_superblock_csum_verify(struct super_block *sb,
141 				struct ext4_super_block *es)
142 {
143 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
144 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
145 		return 1;
146 
147 	return es->s_checksum == ext4_superblock_csum(sb, es);
148 }
149 
150 void ext4_superblock_csum_set(struct super_block *sb)
151 {
152 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
153 
154 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
155 		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
156 		return;
157 
158 	es->s_checksum = ext4_superblock_csum(sb, es);
159 }
160 
161 void *ext4_kvmalloc(size_t size, gfp_t flags)
162 {
163 	void *ret;
164 
165 	ret = kmalloc(size, flags | __GFP_NOWARN);
166 	if (!ret)
167 		ret = __vmalloc(size, flags, PAGE_KERNEL);
168 	return ret;
169 }
170 
171 void *ext4_kvzalloc(size_t size, gfp_t flags)
172 {
173 	void *ret;
174 
175 	ret = kzalloc(size, flags | __GFP_NOWARN);
176 	if (!ret)
177 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
178 	return ret;
179 }
180 
181 void ext4_kvfree(void *ptr)
182 {
183 	if (is_vmalloc_addr(ptr))
184 		vfree(ptr);
185 	else
186 		kfree(ptr);
187 
188 }
189 
190 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
191 			       struct ext4_group_desc *bg)
192 {
193 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
194 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
195 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
196 }
197 
198 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
199 			       struct ext4_group_desc *bg)
200 {
201 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
202 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
203 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
204 }
205 
206 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
207 			      struct ext4_group_desc *bg)
208 {
209 	return le32_to_cpu(bg->bg_inode_table_lo) |
210 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
211 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
212 }
213 
214 __u32 ext4_free_group_clusters(struct super_block *sb,
215 			       struct ext4_group_desc *bg)
216 {
217 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
218 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
219 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
220 }
221 
222 __u32 ext4_free_inodes_count(struct super_block *sb,
223 			      struct ext4_group_desc *bg)
224 {
225 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
226 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
227 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
228 }
229 
230 __u32 ext4_used_dirs_count(struct super_block *sb,
231 			      struct ext4_group_desc *bg)
232 {
233 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
234 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
235 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
236 }
237 
238 __u32 ext4_itable_unused_count(struct super_block *sb,
239 			      struct ext4_group_desc *bg)
240 {
241 	return le16_to_cpu(bg->bg_itable_unused_lo) |
242 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
243 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
244 }
245 
246 void ext4_block_bitmap_set(struct super_block *sb,
247 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
248 {
249 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
250 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
251 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
252 }
253 
254 void ext4_inode_bitmap_set(struct super_block *sb,
255 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
256 {
257 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
258 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
259 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
260 }
261 
262 void ext4_inode_table_set(struct super_block *sb,
263 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
264 {
265 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
266 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
267 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
268 }
269 
270 void ext4_free_group_clusters_set(struct super_block *sb,
271 				  struct ext4_group_desc *bg, __u32 count)
272 {
273 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
274 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
275 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
276 }
277 
278 void ext4_free_inodes_set(struct super_block *sb,
279 			  struct ext4_group_desc *bg, __u32 count)
280 {
281 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
282 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
283 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
284 }
285 
286 void ext4_used_dirs_set(struct super_block *sb,
287 			  struct ext4_group_desc *bg, __u32 count)
288 {
289 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
290 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
291 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
292 }
293 
294 void ext4_itable_unused_set(struct super_block *sb,
295 			  struct ext4_group_desc *bg, __u32 count)
296 {
297 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
298 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
299 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
300 }
301 
302 
303 static void __save_error_info(struct super_block *sb, const char *func,
304 			    unsigned int line)
305 {
306 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
307 
308 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
309 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
310 	es->s_last_error_time = cpu_to_le32(get_seconds());
311 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
312 	es->s_last_error_line = cpu_to_le32(line);
313 	if (!es->s_first_error_time) {
314 		es->s_first_error_time = es->s_last_error_time;
315 		strncpy(es->s_first_error_func, func,
316 			sizeof(es->s_first_error_func));
317 		es->s_first_error_line = cpu_to_le32(line);
318 		es->s_first_error_ino = es->s_last_error_ino;
319 		es->s_first_error_block = es->s_last_error_block;
320 	}
321 	/*
322 	 * Start the daily error reporting function if it hasn't been
323 	 * started already
324 	 */
325 	if (!es->s_error_count)
326 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
327 	le32_add_cpu(&es->s_error_count, 1);
328 }
329 
330 static void save_error_info(struct super_block *sb, const char *func,
331 			    unsigned int line)
332 {
333 	__save_error_info(sb, func, line);
334 	ext4_commit_super(sb, 1);
335 }
336 
337 /*
338  * The del_gendisk() function uninitializes the disk-specific data
339  * structures, including the bdi structure, without telling anyone
340  * else.  Once this happens, any attempt to call mark_buffer_dirty()
341  * (for example, by ext4_commit_super), will cause a kernel OOPS.
342  * This is a kludge to prevent these oops until we can put in a proper
343  * hook in del_gendisk() to inform the VFS and file system layers.
344  */
345 static int block_device_ejected(struct super_block *sb)
346 {
347 	struct inode *bd_inode = sb->s_bdev->bd_inode;
348 	struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
349 
350 	return bdi->dev == NULL;
351 }
352 
353 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
354 {
355 	struct super_block		*sb = journal->j_private;
356 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
357 	int				error = is_journal_aborted(journal);
358 	struct ext4_journal_cb_entry	*jce;
359 
360 	BUG_ON(txn->t_state == T_FINISHED);
361 	spin_lock(&sbi->s_md_lock);
362 	while (!list_empty(&txn->t_private_list)) {
363 		jce = list_entry(txn->t_private_list.next,
364 				 struct ext4_journal_cb_entry, jce_list);
365 		list_del_init(&jce->jce_list);
366 		spin_unlock(&sbi->s_md_lock);
367 		jce->jce_func(sb, jce, error);
368 		spin_lock(&sbi->s_md_lock);
369 	}
370 	spin_unlock(&sbi->s_md_lock);
371 }
372 
373 /* Deal with the reporting of failure conditions on a filesystem such as
374  * inconsistencies detected or read IO failures.
375  *
376  * On ext2, we can store the error state of the filesystem in the
377  * superblock.  That is not possible on ext4, because we may have other
378  * write ordering constraints on the superblock which prevent us from
379  * writing it out straight away; and given that the journal is about to
380  * be aborted, we can't rely on the current, or future, transactions to
381  * write out the superblock safely.
382  *
383  * We'll just use the jbd2_journal_abort() error code to record an error in
384  * the journal instead.  On recovery, the journal will complain about
385  * that error until we've noted it down and cleared it.
386  */
387 
388 static void ext4_handle_error(struct super_block *sb)
389 {
390 	if (sb->s_flags & MS_RDONLY)
391 		return;
392 
393 	if (!test_opt(sb, ERRORS_CONT)) {
394 		journal_t *journal = EXT4_SB(sb)->s_journal;
395 
396 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
397 		if (journal)
398 			jbd2_journal_abort(journal, -EIO);
399 	}
400 	if (test_opt(sb, ERRORS_RO)) {
401 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
402 		/*
403 		 * Make sure updated value of ->s_mount_flags will be visible
404 		 * before ->s_flags update
405 		 */
406 		smp_wmb();
407 		sb->s_flags |= MS_RDONLY;
408 	}
409 	if (test_opt(sb, ERRORS_PANIC))
410 		panic("EXT4-fs (device %s): panic forced after error\n",
411 			sb->s_id);
412 }
413 
414 void __ext4_error(struct super_block *sb, const char *function,
415 		  unsigned int line, const char *fmt, ...)
416 {
417 	struct va_format vaf;
418 	va_list args;
419 
420 	va_start(args, fmt);
421 	vaf.fmt = fmt;
422 	vaf.va = &args;
423 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
424 	       sb->s_id, function, line, current->comm, &vaf);
425 	va_end(args);
426 	save_error_info(sb, function, line);
427 
428 	ext4_handle_error(sb);
429 }
430 
431 void __ext4_error_inode(struct inode *inode, const char *function,
432 			unsigned int line, ext4_fsblk_t block,
433 			const char *fmt, ...)
434 {
435 	va_list args;
436 	struct va_format vaf;
437 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
438 
439 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
440 	es->s_last_error_block = cpu_to_le64(block);
441 	save_error_info(inode->i_sb, function, line);
442 	va_start(args, fmt);
443 	vaf.fmt = fmt;
444 	vaf.va = &args;
445 	if (block)
446 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
447 		       "inode #%lu: block %llu: comm %s: %pV\n",
448 		       inode->i_sb->s_id, function, line, inode->i_ino,
449 		       block, current->comm, &vaf);
450 	else
451 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
452 		       "inode #%lu: comm %s: %pV\n",
453 		       inode->i_sb->s_id, function, line, inode->i_ino,
454 		       current->comm, &vaf);
455 	va_end(args);
456 
457 	ext4_handle_error(inode->i_sb);
458 }
459 
460 void __ext4_error_file(struct file *file, const char *function,
461 		       unsigned int line, ext4_fsblk_t block,
462 		       const char *fmt, ...)
463 {
464 	va_list args;
465 	struct va_format vaf;
466 	struct ext4_super_block *es;
467 	struct inode *inode = file_inode(file);
468 	char pathname[80], *path;
469 
470 	es = EXT4_SB(inode->i_sb)->s_es;
471 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
472 	save_error_info(inode->i_sb, function, line);
473 	path = d_path(&(file->f_path), pathname, sizeof(pathname));
474 	if (IS_ERR(path))
475 		path = "(unknown)";
476 	va_start(args, fmt);
477 	vaf.fmt = fmt;
478 	vaf.va = &args;
479 	if (block)
480 		printk(KERN_CRIT
481 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
482 		       "block %llu: comm %s: path %s: %pV\n",
483 		       inode->i_sb->s_id, function, line, inode->i_ino,
484 		       block, current->comm, path, &vaf);
485 	else
486 		printk(KERN_CRIT
487 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
488 		       "comm %s: path %s: %pV\n",
489 		       inode->i_sb->s_id, function, line, inode->i_ino,
490 		       current->comm, path, &vaf);
491 	va_end(args);
492 
493 	ext4_handle_error(inode->i_sb);
494 }
495 
496 const char *ext4_decode_error(struct super_block *sb, int errno,
497 			      char nbuf[16])
498 {
499 	char *errstr = NULL;
500 
501 	switch (errno) {
502 	case -EIO:
503 		errstr = "IO failure";
504 		break;
505 	case -ENOMEM:
506 		errstr = "Out of memory";
507 		break;
508 	case -EROFS:
509 		if (!sb || (EXT4_SB(sb)->s_journal &&
510 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
511 			errstr = "Journal has aborted";
512 		else
513 			errstr = "Readonly filesystem";
514 		break;
515 	default:
516 		/* If the caller passed in an extra buffer for unknown
517 		 * errors, textualise them now.  Else we just return
518 		 * NULL. */
519 		if (nbuf) {
520 			/* Check for truncated error codes... */
521 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
522 				errstr = nbuf;
523 		}
524 		break;
525 	}
526 
527 	return errstr;
528 }
529 
530 /* __ext4_std_error decodes expected errors from journaling functions
531  * automatically and invokes the appropriate error response.  */
532 
533 void __ext4_std_error(struct super_block *sb, const char *function,
534 		      unsigned int line, int errno)
535 {
536 	char nbuf[16];
537 	const char *errstr;
538 
539 	/* Special case: if the error is EROFS, and we're not already
540 	 * inside a transaction, then there's really no point in logging
541 	 * an error. */
542 	if (errno == -EROFS && journal_current_handle() == NULL &&
543 	    (sb->s_flags & MS_RDONLY))
544 		return;
545 
546 	errstr = ext4_decode_error(sb, errno, nbuf);
547 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
548 	       sb->s_id, function, line, errstr);
549 	save_error_info(sb, function, line);
550 
551 	ext4_handle_error(sb);
552 }
553 
554 /*
555  * ext4_abort is a much stronger failure handler than ext4_error.  The
556  * abort function may be used to deal with unrecoverable failures such
557  * as journal IO errors or ENOMEM at a critical moment in log management.
558  *
559  * We unconditionally force the filesystem into an ABORT|READONLY state,
560  * unless the error response on the fs has been set to panic in which
561  * case we take the easy way out and panic immediately.
562  */
563 
564 void __ext4_abort(struct super_block *sb, const char *function,
565 		unsigned int line, const char *fmt, ...)
566 {
567 	va_list args;
568 
569 	save_error_info(sb, function, line);
570 	va_start(args, fmt);
571 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
572 	       function, line);
573 	vprintk(fmt, args);
574 	printk("\n");
575 	va_end(args);
576 
577 	if ((sb->s_flags & MS_RDONLY) == 0) {
578 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
579 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
580 		/*
581 		 * Make sure updated value of ->s_mount_flags will be visible
582 		 * before ->s_flags update
583 		 */
584 		smp_wmb();
585 		sb->s_flags |= MS_RDONLY;
586 		if (EXT4_SB(sb)->s_journal)
587 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
588 		save_error_info(sb, function, line);
589 	}
590 	if (test_opt(sb, ERRORS_PANIC))
591 		panic("EXT4-fs panic from previous error\n");
592 }
593 
594 void __ext4_msg(struct super_block *sb,
595 		const char *prefix, const char *fmt, ...)
596 {
597 	struct va_format vaf;
598 	va_list args;
599 
600 	va_start(args, fmt);
601 	vaf.fmt = fmt;
602 	vaf.va = &args;
603 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
604 	va_end(args);
605 }
606 
607 void __ext4_warning(struct super_block *sb, const char *function,
608 		    unsigned int line, const char *fmt, ...)
609 {
610 	struct va_format vaf;
611 	va_list args;
612 
613 	va_start(args, fmt);
614 	vaf.fmt = fmt;
615 	vaf.va = &args;
616 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
617 	       sb->s_id, function, line, &vaf);
618 	va_end(args);
619 }
620 
621 void __ext4_grp_locked_error(const char *function, unsigned int line,
622 			     struct super_block *sb, ext4_group_t grp,
623 			     unsigned long ino, ext4_fsblk_t block,
624 			     const char *fmt, ...)
625 __releases(bitlock)
626 __acquires(bitlock)
627 {
628 	struct va_format vaf;
629 	va_list args;
630 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
631 
632 	es->s_last_error_ino = cpu_to_le32(ino);
633 	es->s_last_error_block = cpu_to_le64(block);
634 	__save_error_info(sb, function, line);
635 
636 	va_start(args, fmt);
637 
638 	vaf.fmt = fmt;
639 	vaf.va = &args;
640 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
641 	       sb->s_id, function, line, grp);
642 	if (ino)
643 		printk(KERN_CONT "inode %lu: ", ino);
644 	if (block)
645 		printk(KERN_CONT "block %llu:", (unsigned long long) block);
646 	printk(KERN_CONT "%pV\n", &vaf);
647 	va_end(args);
648 
649 	if (test_opt(sb, ERRORS_CONT)) {
650 		ext4_commit_super(sb, 0);
651 		return;
652 	}
653 
654 	ext4_unlock_group(sb, grp);
655 	ext4_handle_error(sb);
656 	/*
657 	 * We only get here in the ERRORS_RO case; relocking the group
658 	 * may be dangerous, but nothing bad will happen since the
659 	 * filesystem will have already been marked read/only and the
660 	 * journal has been aborted.  We return 1 as a hint to callers
661 	 * who might what to use the return value from
662 	 * ext4_grp_locked_error() to distinguish between the
663 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
664 	 * aggressively from the ext4 function in question, with a
665 	 * more appropriate error code.
666 	 */
667 	ext4_lock_group(sb, grp);
668 	return;
669 }
670 
671 void ext4_update_dynamic_rev(struct super_block *sb)
672 {
673 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
674 
675 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
676 		return;
677 
678 	ext4_warning(sb,
679 		     "updating to rev %d because of new feature flag, "
680 		     "running e2fsck is recommended",
681 		     EXT4_DYNAMIC_REV);
682 
683 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
684 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
685 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
686 	/* leave es->s_feature_*compat flags alone */
687 	/* es->s_uuid will be set by e2fsck if empty */
688 
689 	/*
690 	 * The rest of the superblock fields should be zero, and if not it
691 	 * means they are likely already in use, so leave them alone.  We
692 	 * can leave it up to e2fsck to clean up any inconsistencies there.
693 	 */
694 }
695 
696 /*
697  * Open the external journal device
698  */
699 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
700 {
701 	struct block_device *bdev;
702 	char b[BDEVNAME_SIZE];
703 
704 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
705 	if (IS_ERR(bdev))
706 		goto fail;
707 	return bdev;
708 
709 fail:
710 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
711 			__bdevname(dev, b), PTR_ERR(bdev));
712 	return NULL;
713 }
714 
715 /*
716  * Release the journal device
717  */
718 static void ext4_blkdev_put(struct block_device *bdev)
719 {
720 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
721 }
722 
723 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
724 {
725 	struct block_device *bdev;
726 	bdev = sbi->journal_bdev;
727 	if (bdev) {
728 		ext4_blkdev_put(bdev);
729 		sbi->journal_bdev = NULL;
730 	}
731 }
732 
733 static inline struct inode *orphan_list_entry(struct list_head *l)
734 {
735 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
736 }
737 
738 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
739 {
740 	struct list_head *l;
741 
742 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
743 		 le32_to_cpu(sbi->s_es->s_last_orphan));
744 
745 	printk(KERN_ERR "sb_info orphan list:\n");
746 	list_for_each(l, &sbi->s_orphan) {
747 		struct inode *inode = orphan_list_entry(l);
748 		printk(KERN_ERR "  "
749 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
750 		       inode->i_sb->s_id, inode->i_ino, inode,
751 		       inode->i_mode, inode->i_nlink,
752 		       NEXT_ORPHAN(inode));
753 	}
754 }
755 
756 static void ext4_put_super(struct super_block *sb)
757 {
758 	struct ext4_sb_info *sbi = EXT4_SB(sb);
759 	struct ext4_super_block *es = sbi->s_es;
760 	int i, err;
761 
762 	ext4_unregister_li_request(sb);
763 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
764 
765 	flush_workqueue(sbi->rsv_conversion_wq);
766 	destroy_workqueue(sbi->rsv_conversion_wq);
767 
768 	if (sbi->s_journal) {
769 		err = jbd2_journal_destroy(sbi->s_journal);
770 		sbi->s_journal = NULL;
771 		if (err < 0)
772 			ext4_abort(sb, "Couldn't clean up the journal");
773 	}
774 
775 	ext4_es_unregister_shrinker(sbi);
776 	del_timer(&sbi->s_err_report);
777 	ext4_release_system_zone(sb);
778 	ext4_mb_release(sb);
779 	ext4_ext_release(sb);
780 	ext4_xattr_put_super(sb);
781 
782 	if (!(sb->s_flags & MS_RDONLY)) {
783 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
784 		es->s_state = cpu_to_le16(sbi->s_mount_state);
785 	}
786 	if (!(sb->s_flags & MS_RDONLY))
787 		ext4_commit_super(sb, 1);
788 
789 	if (sbi->s_proc) {
790 		remove_proc_entry("options", sbi->s_proc);
791 		remove_proc_entry(sb->s_id, ext4_proc_root);
792 	}
793 	kobject_del(&sbi->s_kobj);
794 
795 	for (i = 0; i < sbi->s_gdb_count; i++)
796 		brelse(sbi->s_group_desc[i]);
797 	ext4_kvfree(sbi->s_group_desc);
798 	ext4_kvfree(sbi->s_flex_groups);
799 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
800 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
801 	percpu_counter_destroy(&sbi->s_dirs_counter);
802 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
803 	percpu_counter_destroy(&sbi->s_extent_cache_cnt);
804 	brelse(sbi->s_sbh);
805 #ifdef CONFIG_QUOTA
806 	for (i = 0; i < MAXQUOTAS; i++)
807 		kfree(sbi->s_qf_names[i]);
808 #endif
809 
810 	/* Debugging code just in case the in-memory inode orphan list
811 	 * isn't empty.  The on-disk one can be non-empty if we've
812 	 * detected an error and taken the fs readonly, but the
813 	 * in-memory list had better be clean by this point. */
814 	if (!list_empty(&sbi->s_orphan))
815 		dump_orphan_list(sb, sbi);
816 	J_ASSERT(list_empty(&sbi->s_orphan));
817 
818 	invalidate_bdev(sb->s_bdev);
819 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
820 		/*
821 		 * Invalidate the journal device's buffers.  We don't want them
822 		 * floating about in memory - the physical journal device may
823 		 * hotswapped, and it breaks the `ro-after' testing code.
824 		 */
825 		sync_blockdev(sbi->journal_bdev);
826 		invalidate_bdev(sbi->journal_bdev);
827 		ext4_blkdev_remove(sbi);
828 	}
829 	if (sbi->s_mmp_tsk)
830 		kthread_stop(sbi->s_mmp_tsk);
831 	sb->s_fs_info = NULL;
832 	/*
833 	 * Now that we are completely done shutting down the
834 	 * superblock, we need to actually destroy the kobject.
835 	 */
836 	kobject_put(&sbi->s_kobj);
837 	wait_for_completion(&sbi->s_kobj_unregister);
838 	if (sbi->s_chksum_driver)
839 		crypto_free_shash(sbi->s_chksum_driver);
840 	kfree(sbi->s_blockgroup_lock);
841 	kfree(sbi);
842 }
843 
844 static struct kmem_cache *ext4_inode_cachep;
845 
846 /*
847  * Called inside transaction, so use GFP_NOFS
848  */
849 static struct inode *ext4_alloc_inode(struct super_block *sb)
850 {
851 	struct ext4_inode_info *ei;
852 
853 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
854 	if (!ei)
855 		return NULL;
856 
857 	ei->vfs_inode.i_version = 1;
858 	INIT_LIST_HEAD(&ei->i_prealloc_list);
859 	spin_lock_init(&ei->i_prealloc_lock);
860 	ext4_es_init_tree(&ei->i_es_tree);
861 	rwlock_init(&ei->i_es_lock);
862 	INIT_LIST_HEAD(&ei->i_es_lru);
863 	ei->i_es_lru_nr = 0;
864 	ei->i_touch_when = 0;
865 	ei->i_reserved_data_blocks = 0;
866 	ei->i_reserved_meta_blocks = 0;
867 	ei->i_allocated_meta_blocks = 0;
868 	ei->i_da_metadata_calc_len = 0;
869 	ei->i_da_metadata_calc_last_lblock = 0;
870 	spin_lock_init(&(ei->i_block_reservation_lock));
871 #ifdef CONFIG_QUOTA
872 	ei->i_reserved_quota = 0;
873 #endif
874 	ei->jinode = NULL;
875 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
876 	spin_lock_init(&ei->i_completed_io_lock);
877 	ei->i_sync_tid = 0;
878 	ei->i_datasync_tid = 0;
879 	atomic_set(&ei->i_ioend_count, 0);
880 	atomic_set(&ei->i_unwritten, 0);
881 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
882 
883 	return &ei->vfs_inode;
884 }
885 
886 static int ext4_drop_inode(struct inode *inode)
887 {
888 	int drop = generic_drop_inode(inode);
889 
890 	trace_ext4_drop_inode(inode, drop);
891 	return drop;
892 }
893 
894 static void ext4_i_callback(struct rcu_head *head)
895 {
896 	struct inode *inode = container_of(head, struct inode, i_rcu);
897 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
898 }
899 
900 static void ext4_destroy_inode(struct inode *inode)
901 {
902 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
903 		ext4_msg(inode->i_sb, KERN_ERR,
904 			 "Inode %lu (%p): orphan list check failed!",
905 			 inode->i_ino, EXT4_I(inode));
906 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
907 				EXT4_I(inode), sizeof(struct ext4_inode_info),
908 				true);
909 		dump_stack();
910 	}
911 	call_rcu(&inode->i_rcu, ext4_i_callback);
912 }
913 
914 static void init_once(void *foo)
915 {
916 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
917 
918 	INIT_LIST_HEAD(&ei->i_orphan);
919 	init_rwsem(&ei->xattr_sem);
920 	init_rwsem(&ei->i_data_sem);
921 	inode_init_once(&ei->vfs_inode);
922 }
923 
924 static int init_inodecache(void)
925 {
926 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
927 					     sizeof(struct ext4_inode_info),
928 					     0, (SLAB_RECLAIM_ACCOUNT|
929 						SLAB_MEM_SPREAD),
930 					     init_once);
931 	if (ext4_inode_cachep == NULL)
932 		return -ENOMEM;
933 	return 0;
934 }
935 
936 static void destroy_inodecache(void)
937 {
938 	/*
939 	 * Make sure all delayed rcu free inodes are flushed before we
940 	 * destroy cache.
941 	 */
942 	rcu_barrier();
943 	kmem_cache_destroy(ext4_inode_cachep);
944 }
945 
946 void ext4_clear_inode(struct inode *inode)
947 {
948 	invalidate_inode_buffers(inode);
949 	clear_inode(inode);
950 	dquot_drop(inode);
951 	ext4_discard_preallocations(inode);
952 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
953 	ext4_es_lru_del(inode);
954 	if (EXT4_I(inode)->jinode) {
955 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
956 					       EXT4_I(inode)->jinode);
957 		jbd2_free_inode(EXT4_I(inode)->jinode);
958 		EXT4_I(inode)->jinode = NULL;
959 	}
960 }
961 
962 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
963 					u64 ino, u32 generation)
964 {
965 	struct inode *inode;
966 
967 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
968 		return ERR_PTR(-ESTALE);
969 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
970 		return ERR_PTR(-ESTALE);
971 
972 	/* iget isn't really right if the inode is currently unallocated!!
973 	 *
974 	 * ext4_read_inode will return a bad_inode if the inode had been
975 	 * deleted, so we should be safe.
976 	 *
977 	 * Currently we don't know the generation for parent directory, so
978 	 * a generation of 0 means "accept any"
979 	 */
980 	inode = ext4_iget(sb, ino);
981 	if (IS_ERR(inode))
982 		return ERR_CAST(inode);
983 	if (generation && inode->i_generation != generation) {
984 		iput(inode);
985 		return ERR_PTR(-ESTALE);
986 	}
987 
988 	return inode;
989 }
990 
991 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
992 					int fh_len, int fh_type)
993 {
994 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
995 				    ext4_nfs_get_inode);
996 }
997 
998 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
999 					int fh_len, int fh_type)
1000 {
1001 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1002 				    ext4_nfs_get_inode);
1003 }
1004 
1005 /*
1006  * Try to release metadata pages (indirect blocks, directories) which are
1007  * mapped via the block device.  Since these pages could have journal heads
1008  * which would prevent try_to_free_buffers() from freeing them, we must use
1009  * jbd2 layer's try_to_free_buffers() function to release them.
1010  */
1011 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1012 				 gfp_t wait)
1013 {
1014 	journal_t *journal = EXT4_SB(sb)->s_journal;
1015 
1016 	WARN_ON(PageChecked(page));
1017 	if (!page_has_buffers(page))
1018 		return 0;
1019 	if (journal)
1020 		return jbd2_journal_try_to_free_buffers(journal, page,
1021 							wait & ~__GFP_WAIT);
1022 	return try_to_free_buffers(page);
1023 }
1024 
1025 #ifdef CONFIG_QUOTA
1026 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1027 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1028 
1029 static int ext4_write_dquot(struct dquot *dquot);
1030 static int ext4_acquire_dquot(struct dquot *dquot);
1031 static int ext4_release_dquot(struct dquot *dquot);
1032 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1033 static int ext4_write_info(struct super_block *sb, int type);
1034 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1035 			 struct path *path);
1036 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1037 				 int format_id);
1038 static int ext4_quota_off(struct super_block *sb, int type);
1039 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1040 static int ext4_quota_on_mount(struct super_block *sb, int type);
1041 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1042 			       size_t len, loff_t off);
1043 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1044 				const char *data, size_t len, loff_t off);
1045 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1046 			     unsigned int flags);
1047 static int ext4_enable_quotas(struct super_block *sb);
1048 
1049 static const struct dquot_operations ext4_quota_operations = {
1050 	.get_reserved_space = ext4_get_reserved_space,
1051 	.write_dquot	= ext4_write_dquot,
1052 	.acquire_dquot	= ext4_acquire_dquot,
1053 	.release_dquot	= ext4_release_dquot,
1054 	.mark_dirty	= ext4_mark_dquot_dirty,
1055 	.write_info	= ext4_write_info,
1056 	.alloc_dquot	= dquot_alloc,
1057 	.destroy_dquot	= dquot_destroy,
1058 };
1059 
1060 static const struct quotactl_ops ext4_qctl_operations = {
1061 	.quota_on	= ext4_quota_on,
1062 	.quota_off	= ext4_quota_off,
1063 	.quota_sync	= dquot_quota_sync,
1064 	.get_info	= dquot_get_dqinfo,
1065 	.set_info	= dquot_set_dqinfo,
1066 	.get_dqblk	= dquot_get_dqblk,
1067 	.set_dqblk	= dquot_set_dqblk
1068 };
1069 
1070 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1071 	.quota_on_meta	= ext4_quota_on_sysfile,
1072 	.quota_off	= ext4_quota_off_sysfile,
1073 	.quota_sync	= dquot_quota_sync,
1074 	.get_info	= dquot_get_dqinfo,
1075 	.set_info	= dquot_set_dqinfo,
1076 	.get_dqblk	= dquot_get_dqblk,
1077 	.set_dqblk	= dquot_set_dqblk
1078 };
1079 #endif
1080 
1081 static const struct super_operations ext4_sops = {
1082 	.alloc_inode	= ext4_alloc_inode,
1083 	.destroy_inode	= ext4_destroy_inode,
1084 	.write_inode	= ext4_write_inode,
1085 	.dirty_inode	= ext4_dirty_inode,
1086 	.drop_inode	= ext4_drop_inode,
1087 	.evict_inode	= ext4_evict_inode,
1088 	.put_super	= ext4_put_super,
1089 	.sync_fs	= ext4_sync_fs,
1090 	.freeze_fs	= ext4_freeze,
1091 	.unfreeze_fs	= ext4_unfreeze,
1092 	.statfs		= ext4_statfs,
1093 	.remount_fs	= ext4_remount,
1094 	.show_options	= ext4_show_options,
1095 #ifdef CONFIG_QUOTA
1096 	.quota_read	= ext4_quota_read,
1097 	.quota_write	= ext4_quota_write,
1098 #endif
1099 	.bdev_try_to_free_page = bdev_try_to_free_page,
1100 };
1101 
1102 static const struct super_operations ext4_nojournal_sops = {
1103 	.alloc_inode	= ext4_alloc_inode,
1104 	.destroy_inode	= ext4_destroy_inode,
1105 	.write_inode	= ext4_write_inode,
1106 	.dirty_inode	= ext4_dirty_inode,
1107 	.drop_inode	= ext4_drop_inode,
1108 	.evict_inode	= ext4_evict_inode,
1109 	.sync_fs	= ext4_sync_fs_nojournal,
1110 	.put_super	= ext4_put_super,
1111 	.statfs		= ext4_statfs,
1112 	.remount_fs	= ext4_remount,
1113 	.show_options	= ext4_show_options,
1114 #ifdef CONFIG_QUOTA
1115 	.quota_read	= ext4_quota_read,
1116 	.quota_write	= ext4_quota_write,
1117 #endif
1118 	.bdev_try_to_free_page = bdev_try_to_free_page,
1119 };
1120 
1121 static const struct export_operations ext4_export_ops = {
1122 	.fh_to_dentry = ext4_fh_to_dentry,
1123 	.fh_to_parent = ext4_fh_to_parent,
1124 	.get_parent = ext4_get_parent,
1125 };
1126 
1127 enum {
1128 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1129 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1130 	Opt_nouid32, Opt_debug, Opt_removed,
1131 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1132 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1133 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1134 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1135 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1136 	Opt_data_err_abort, Opt_data_err_ignore,
1137 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1138 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1139 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1140 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1141 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1142 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1143 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1144 	Opt_dioread_nolock, Opt_dioread_lock,
1145 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1146 	Opt_max_dir_size_kb,
1147 };
1148 
1149 static const match_table_t tokens = {
1150 	{Opt_bsd_df, "bsddf"},
1151 	{Opt_minix_df, "minixdf"},
1152 	{Opt_grpid, "grpid"},
1153 	{Opt_grpid, "bsdgroups"},
1154 	{Opt_nogrpid, "nogrpid"},
1155 	{Opt_nogrpid, "sysvgroups"},
1156 	{Opt_resgid, "resgid=%u"},
1157 	{Opt_resuid, "resuid=%u"},
1158 	{Opt_sb, "sb=%u"},
1159 	{Opt_err_cont, "errors=continue"},
1160 	{Opt_err_panic, "errors=panic"},
1161 	{Opt_err_ro, "errors=remount-ro"},
1162 	{Opt_nouid32, "nouid32"},
1163 	{Opt_debug, "debug"},
1164 	{Opt_removed, "oldalloc"},
1165 	{Opt_removed, "orlov"},
1166 	{Opt_user_xattr, "user_xattr"},
1167 	{Opt_nouser_xattr, "nouser_xattr"},
1168 	{Opt_acl, "acl"},
1169 	{Opt_noacl, "noacl"},
1170 	{Opt_noload, "norecovery"},
1171 	{Opt_noload, "noload"},
1172 	{Opt_removed, "nobh"},
1173 	{Opt_removed, "bh"},
1174 	{Opt_commit, "commit=%u"},
1175 	{Opt_min_batch_time, "min_batch_time=%u"},
1176 	{Opt_max_batch_time, "max_batch_time=%u"},
1177 	{Opt_journal_dev, "journal_dev=%u"},
1178 	{Opt_journal_path, "journal_path=%s"},
1179 	{Opt_journal_checksum, "journal_checksum"},
1180 	{Opt_journal_async_commit, "journal_async_commit"},
1181 	{Opt_abort, "abort"},
1182 	{Opt_data_journal, "data=journal"},
1183 	{Opt_data_ordered, "data=ordered"},
1184 	{Opt_data_writeback, "data=writeback"},
1185 	{Opt_data_err_abort, "data_err=abort"},
1186 	{Opt_data_err_ignore, "data_err=ignore"},
1187 	{Opt_offusrjquota, "usrjquota="},
1188 	{Opt_usrjquota, "usrjquota=%s"},
1189 	{Opt_offgrpjquota, "grpjquota="},
1190 	{Opt_grpjquota, "grpjquota=%s"},
1191 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1192 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1193 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1194 	{Opt_grpquota, "grpquota"},
1195 	{Opt_noquota, "noquota"},
1196 	{Opt_quota, "quota"},
1197 	{Opt_usrquota, "usrquota"},
1198 	{Opt_barrier, "barrier=%u"},
1199 	{Opt_barrier, "barrier"},
1200 	{Opt_nobarrier, "nobarrier"},
1201 	{Opt_i_version, "i_version"},
1202 	{Opt_stripe, "stripe=%u"},
1203 	{Opt_delalloc, "delalloc"},
1204 	{Opt_nodelalloc, "nodelalloc"},
1205 	{Opt_removed, "mblk_io_submit"},
1206 	{Opt_removed, "nomblk_io_submit"},
1207 	{Opt_block_validity, "block_validity"},
1208 	{Opt_noblock_validity, "noblock_validity"},
1209 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1210 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1211 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1212 	{Opt_auto_da_alloc, "auto_da_alloc"},
1213 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1214 	{Opt_dioread_nolock, "dioread_nolock"},
1215 	{Opt_dioread_lock, "dioread_lock"},
1216 	{Opt_discard, "discard"},
1217 	{Opt_nodiscard, "nodiscard"},
1218 	{Opt_init_itable, "init_itable=%u"},
1219 	{Opt_init_itable, "init_itable"},
1220 	{Opt_noinit_itable, "noinit_itable"},
1221 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1222 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1223 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1224 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1225 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1226 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1227 	{Opt_err, NULL},
1228 };
1229 
1230 static ext4_fsblk_t get_sb_block(void **data)
1231 {
1232 	ext4_fsblk_t	sb_block;
1233 	char		*options = (char *) *data;
1234 
1235 	if (!options || strncmp(options, "sb=", 3) != 0)
1236 		return 1;	/* Default location */
1237 
1238 	options += 3;
1239 	/* TODO: use simple_strtoll with >32bit ext4 */
1240 	sb_block = simple_strtoul(options, &options, 0);
1241 	if (*options && *options != ',') {
1242 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1243 		       (char *) *data);
1244 		return 1;
1245 	}
1246 	if (*options == ',')
1247 		options++;
1248 	*data = (void *) options;
1249 
1250 	return sb_block;
1251 }
1252 
1253 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1254 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1255 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1256 
1257 #ifdef CONFIG_QUOTA
1258 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1259 {
1260 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1261 	char *qname;
1262 	int ret = -1;
1263 
1264 	if (sb_any_quota_loaded(sb) &&
1265 		!sbi->s_qf_names[qtype]) {
1266 		ext4_msg(sb, KERN_ERR,
1267 			"Cannot change journaled "
1268 			"quota options when quota turned on");
1269 		return -1;
1270 	}
1271 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1272 		ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1273 			 "when QUOTA feature is enabled");
1274 		return -1;
1275 	}
1276 	qname = match_strdup(args);
1277 	if (!qname) {
1278 		ext4_msg(sb, KERN_ERR,
1279 			"Not enough memory for storing quotafile name");
1280 		return -1;
1281 	}
1282 	if (sbi->s_qf_names[qtype]) {
1283 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1284 			ret = 1;
1285 		else
1286 			ext4_msg(sb, KERN_ERR,
1287 				 "%s quota file already specified",
1288 				 QTYPE2NAME(qtype));
1289 		goto errout;
1290 	}
1291 	if (strchr(qname, '/')) {
1292 		ext4_msg(sb, KERN_ERR,
1293 			"quotafile must be on filesystem root");
1294 		goto errout;
1295 	}
1296 	sbi->s_qf_names[qtype] = qname;
1297 	set_opt(sb, QUOTA);
1298 	return 1;
1299 errout:
1300 	kfree(qname);
1301 	return ret;
1302 }
1303 
1304 static int clear_qf_name(struct super_block *sb, int qtype)
1305 {
1306 
1307 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1308 
1309 	if (sb_any_quota_loaded(sb) &&
1310 		sbi->s_qf_names[qtype]) {
1311 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1312 			" when quota turned on");
1313 		return -1;
1314 	}
1315 	kfree(sbi->s_qf_names[qtype]);
1316 	sbi->s_qf_names[qtype] = NULL;
1317 	return 1;
1318 }
1319 #endif
1320 
1321 #define MOPT_SET	0x0001
1322 #define MOPT_CLEAR	0x0002
1323 #define MOPT_NOSUPPORT	0x0004
1324 #define MOPT_EXPLICIT	0x0008
1325 #define MOPT_CLEAR_ERR	0x0010
1326 #define MOPT_GTE0	0x0020
1327 #ifdef CONFIG_QUOTA
1328 #define MOPT_Q		0
1329 #define MOPT_QFMT	0x0040
1330 #else
1331 #define MOPT_Q		MOPT_NOSUPPORT
1332 #define MOPT_QFMT	MOPT_NOSUPPORT
1333 #endif
1334 #define MOPT_DATAJ	0x0080
1335 #define MOPT_NO_EXT2	0x0100
1336 #define MOPT_NO_EXT3	0x0200
1337 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1338 #define MOPT_STRING	0x0400
1339 
1340 static const struct mount_opts {
1341 	int	token;
1342 	int	mount_opt;
1343 	int	flags;
1344 } ext4_mount_opts[] = {
1345 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1346 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1347 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1348 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1349 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1350 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1351 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1352 	 MOPT_EXT4_ONLY | MOPT_SET},
1353 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1354 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1355 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1356 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1357 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1358 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1359 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1360 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1361 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1362 	 MOPT_EXT4_ONLY | MOPT_SET},
1363 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1364 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1365 	 MOPT_EXT4_ONLY | MOPT_SET},
1366 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1367 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1368 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1369 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1370 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1371 	 MOPT_NO_EXT2 | MOPT_SET},
1372 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1373 	 MOPT_NO_EXT2 | MOPT_CLEAR},
1374 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1375 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1376 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1377 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1378 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1379 	{Opt_commit, 0, MOPT_GTE0},
1380 	{Opt_max_batch_time, 0, MOPT_GTE0},
1381 	{Opt_min_batch_time, 0, MOPT_GTE0},
1382 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1383 	{Opt_init_itable, 0, MOPT_GTE0},
1384 	{Opt_stripe, 0, MOPT_GTE0},
1385 	{Opt_resuid, 0, MOPT_GTE0},
1386 	{Opt_resgid, 0, MOPT_GTE0},
1387 	{Opt_journal_dev, 0, MOPT_GTE0},
1388 	{Opt_journal_path, 0, MOPT_STRING},
1389 	{Opt_journal_ioprio, 0, MOPT_GTE0},
1390 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1391 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1392 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1393 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1394 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1395 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1396 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1397 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1398 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1399 #else
1400 	{Opt_acl, 0, MOPT_NOSUPPORT},
1401 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1402 #endif
1403 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1404 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1405 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1406 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1407 							MOPT_SET | MOPT_Q},
1408 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1409 							MOPT_SET | MOPT_Q},
1410 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1411 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1412 	{Opt_usrjquota, 0, MOPT_Q},
1413 	{Opt_grpjquota, 0, MOPT_Q},
1414 	{Opt_offusrjquota, 0, MOPT_Q},
1415 	{Opt_offgrpjquota, 0, MOPT_Q},
1416 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1417 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1418 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1419 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1420 	{Opt_err, 0, 0}
1421 };
1422 
1423 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1424 			    substring_t *args, unsigned long *journal_devnum,
1425 			    unsigned int *journal_ioprio, int is_remount)
1426 {
1427 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1428 	const struct mount_opts *m;
1429 	kuid_t uid;
1430 	kgid_t gid;
1431 	int arg = 0;
1432 
1433 #ifdef CONFIG_QUOTA
1434 	if (token == Opt_usrjquota)
1435 		return set_qf_name(sb, USRQUOTA, &args[0]);
1436 	else if (token == Opt_grpjquota)
1437 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1438 	else if (token == Opt_offusrjquota)
1439 		return clear_qf_name(sb, USRQUOTA);
1440 	else if (token == Opt_offgrpjquota)
1441 		return clear_qf_name(sb, GRPQUOTA);
1442 #endif
1443 	switch (token) {
1444 	case Opt_noacl:
1445 	case Opt_nouser_xattr:
1446 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1447 		break;
1448 	case Opt_sb:
1449 		return 1;	/* handled by get_sb_block() */
1450 	case Opt_removed:
1451 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1452 		return 1;
1453 	case Opt_abort:
1454 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1455 		return 1;
1456 	case Opt_i_version:
1457 		sb->s_flags |= MS_I_VERSION;
1458 		return 1;
1459 	}
1460 
1461 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1462 		if (token == m->token)
1463 			break;
1464 
1465 	if (m->token == Opt_err) {
1466 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1467 			 "or missing value", opt);
1468 		return -1;
1469 	}
1470 
1471 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1472 		ext4_msg(sb, KERN_ERR,
1473 			 "Mount option \"%s\" incompatible with ext2", opt);
1474 		return -1;
1475 	}
1476 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1477 		ext4_msg(sb, KERN_ERR,
1478 			 "Mount option \"%s\" incompatible with ext3", opt);
1479 		return -1;
1480 	}
1481 
1482 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1483 		return -1;
1484 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1485 		return -1;
1486 	if (m->flags & MOPT_EXPLICIT)
1487 		set_opt2(sb, EXPLICIT_DELALLOC);
1488 	if (m->flags & MOPT_CLEAR_ERR)
1489 		clear_opt(sb, ERRORS_MASK);
1490 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1491 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1492 			 "options when quota turned on");
1493 		return -1;
1494 	}
1495 
1496 	if (m->flags & MOPT_NOSUPPORT) {
1497 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1498 	} else if (token == Opt_commit) {
1499 		if (arg == 0)
1500 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1501 		sbi->s_commit_interval = HZ * arg;
1502 	} else if (token == Opt_max_batch_time) {
1503 		if (arg == 0)
1504 			arg = EXT4_DEF_MAX_BATCH_TIME;
1505 		sbi->s_max_batch_time = arg;
1506 	} else if (token == Opt_min_batch_time) {
1507 		sbi->s_min_batch_time = arg;
1508 	} else if (token == Opt_inode_readahead_blks) {
1509 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1510 			ext4_msg(sb, KERN_ERR,
1511 				 "EXT4-fs: inode_readahead_blks must be "
1512 				 "0 or a power of 2 smaller than 2^31");
1513 			return -1;
1514 		}
1515 		sbi->s_inode_readahead_blks = arg;
1516 	} else if (token == Opt_init_itable) {
1517 		set_opt(sb, INIT_INODE_TABLE);
1518 		if (!args->from)
1519 			arg = EXT4_DEF_LI_WAIT_MULT;
1520 		sbi->s_li_wait_mult = arg;
1521 	} else if (token == Opt_max_dir_size_kb) {
1522 		sbi->s_max_dir_size_kb = arg;
1523 	} else if (token == Opt_stripe) {
1524 		sbi->s_stripe = arg;
1525 	} else if (token == Opt_resuid) {
1526 		uid = make_kuid(current_user_ns(), arg);
1527 		if (!uid_valid(uid)) {
1528 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1529 			return -1;
1530 		}
1531 		sbi->s_resuid = uid;
1532 	} else if (token == Opt_resgid) {
1533 		gid = make_kgid(current_user_ns(), arg);
1534 		if (!gid_valid(gid)) {
1535 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1536 			return -1;
1537 		}
1538 		sbi->s_resgid = gid;
1539 	} else if (token == Opt_journal_dev) {
1540 		if (is_remount) {
1541 			ext4_msg(sb, KERN_ERR,
1542 				 "Cannot specify journal on remount");
1543 			return -1;
1544 		}
1545 		*journal_devnum = arg;
1546 	} else if (token == Opt_journal_path) {
1547 		char *journal_path;
1548 		struct inode *journal_inode;
1549 		struct path path;
1550 		int error;
1551 
1552 		if (is_remount) {
1553 			ext4_msg(sb, KERN_ERR,
1554 				 "Cannot specify journal on remount");
1555 			return -1;
1556 		}
1557 		journal_path = match_strdup(&args[0]);
1558 		if (!journal_path) {
1559 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1560 				"journal device string");
1561 			return -1;
1562 		}
1563 
1564 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1565 		if (error) {
1566 			ext4_msg(sb, KERN_ERR, "error: could not find "
1567 				"journal device path: error %d", error);
1568 			kfree(journal_path);
1569 			return -1;
1570 		}
1571 
1572 		journal_inode = path.dentry->d_inode;
1573 		if (!S_ISBLK(journal_inode->i_mode)) {
1574 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1575 				"is not a block device", journal_path);
1576 			path_put(&path);
1577 			kfree(journal_path);
1578 			return -1;
1579 		}
1580 
1581 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1582 		path_put(&path);
1583 		kfree(journal_path);
1584 	} else if (token == Opt_journal_ioprio) {
1585 		if (arg > 7) {
1586 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1587 				 " (must be 0-7)");
1588 			return -1;
1589 		}
1590 		*journal_ioprio =
1591 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1592 	} else if (m->flags & MOPT_DATAJ) {
1593 		if (is_remount) {
1594 			if (!sbi->s_journal)
1595 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1596 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1597 				ext4_msg(sb, KERN_ERR,
1598 					 "Cannot change data mode on remount");
1599 				return -1;
1600 			}
1601 		} else {
1602 			clear_opt(sb, DATA_FLAGS);
1603 			sbi->s_mount_opt |= m->mount_opt;
1604 		}
1605 #ifdef CONFIG_QUOTA
1606 	} else if (m->flags & MOPT_QFMT) {
1607 		if (sb_any_quota_loaded(sb) &&
1608 		    sbi->s_jquota_fmt != m->mount_opt) {
1609 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1610 				 "quota options when quota turned on");
1611 			return -1;
1612 		}
1613 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1614 					       EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1615 			ext4_msg(sb, KERN_ERR,
1616 				 "Cannot set journaled quota options "
1617 				 "when QUOTA feature is enabled");
1618 			return -1;
1619 		}
1620 		sbi->s_jquota_fmt = m->mount_opt;
1621 #endif
1622 	} else {
1623 		if (!args->from)
1624 			arg = 1;
1625 		if (m->flags & MOPT_CLEAR)
1626 			arg = !arg;
1627 		else if (unlikely(!(m->flags & MOPT_SET))) {
1628 			ext4_msg(sb, KERN_WARNING,
1629 				 "buggy handling of option %s", opt);
1630 			WARN_ON(1);
1631 			return -1;
1632 		}
1633 		if (arg != 0)
1634 			sbi->s_mount_opt |= m->mount_opt;
1635 		else
1636 			sbi->s_mount_opt &= ~m->mount_opt;
1637 	}
1638 	return 1;
1639 }
1640 
1641 static int parse_options(char *options, struct super_block *sb,
1642 			 unsigned long *journal_devnum,
1643 			 unsigned int *journal_ioprio,
1644 			 int is_remount)
1645 {
1646 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1647 	char *p;
1648 	substring_t args[MAX_OPT_ARGS];
1649 	int token;
1650 
1651 	if (!options)
1652 		return 1;
1653 
1654 	while ((p = strsep(&options, ",")) != NULL) {
1655 		if (!*p)
1656 			continue;
1657 		/*
1658 		 * Initialize args struct so we know whether arg was
1659 		 * found; some options take optional arguments.
1660 		 */
1661 		args[0].to = args[0].from = NULL;
1662 		token = match_token(p, tokens, args);
1663 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1664 				     journal_ioprio, is_remount) < 0)
1665 			return 0;
1666 	}
1667 #ifdef CONFIG_QUOTA
1668 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1669 	    (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1670 		ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1671 			 "feature is enabled");
1672 		return 0;
1673 	}
1674 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1675 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1676 			clear_opt(sb, USRQUOTA);
1677 
1678 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1679 			clear_opt(sb, GRPQUOTA);
1680 
1681 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1682 			ext4_msg(sb, KERN_ERR, "old and new quota "
1683 					"format mixing");
1684 			return 0;
1685 		}
1686 
1687 		if (!sbi->s_jquota_fmt) {
1688 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1689 					"not specified");
1690 			return 0;
1691 		}
1692 	} else {
1693 		if (sbi->s_jquota_fmt) {
1694 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1695 					"specified with no journaling "
1696 					"enabled");
1697 			return 0;
1698 		}
1699 	}
1700 #endif
1701 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1702 		int blocksize =
1703 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1704 
1705 		if (blocksize < PAGE_CACHE_SIZE) {
1706 			ext4_msg(sb, KERN_ERR, "can't mount with "
1707 				 "dioread_nolock if block size != PAGE_SIZE");
1708 			return 0;
1709 		}
1710 	}
1711 	return 1;
1712 }
1713 
1714 static inline void ext4_show_quota_options(struct seq_file *seq,
1715 					   struct super_block *sb)
1716 {
1717 #if defined(CONFIG_QUOTA)
1718 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1719 
1720 	if (sbi->s_jquota_fmt) {
1721 		char *fmtname = "";
1722 
1723 		switch (sbi->s_jquota_fmt) {
1724 		case QFMT_VFS_OLD:
1725 			fmtname = "vfsold";
1726 			break;
1727 		case QFMT_VFS_V0:
1728 			fmtname = "vfsv0";
1729 			break;
1730 		case QFMT_VFS_V1:
1731 			fmtname = "vfsv1";
1732 			break;
1733 		}
1734 		seq_printf(seq, ",jqfmt=%s", fmtname);
1735 	}
1736 
1737 	if (sbi->s_qf_names[USRQUOTA])
1738 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1739 
1740 	if (sbi->s_qf_names[GRPQUOTA])
1741 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1742 #endif
1743 }
1744 
1745 static const char *token2str(int token)
1746 {
1747 	const struct match_token *t;
1748 
1749 	for (t = tokens; t->token != Opt_err; t++)
1750 		if (t->token == token && !strchr(t->pattern, '='))
1751 			break;
1752 	return t->pattern;
1753 }
1754 
1755 /*
1756  * Show an option if
1757  *  - it's set to a non-default value OR
1758  *  - if the per-sb default is different from the global default
1759  */
1760 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1761 			      int nodefs)
1762 {
1763 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1764 	struct ext4_super_block *es = sbi->s_es;
1765 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1766 	const struct mount_opts *m;
1767 	char sep = nodefs ? '\n' : ',';
1768 
1769 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1770 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1771 
1772 	if (sbi->s_sb_block != 1)
1773 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1774 
1775 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1776 		int want_set = m->flags & MOPT_SET;
1777 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1778 		    (m->flags & MOPT_CLEAR_ERR))
1779 			continue;
1780 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1781 			continue; /* skip if same as the default */
1782 		if ((want_set &&
1783 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1784 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1785 			continue; /* select Opt_noFoo vs Opt_Foo */
1786 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1787 	}
1788 
1789 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1790 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1791 		SEQ_OPTS_PRINT("resuid=%u",
1792 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1793 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1794 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1795 		SEQ_OPTS_PRINT("resgid=%u",
1796 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1797 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1798 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1799 		SEQ_OPTS_PUTS("errors=remount-ro");
1800 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1801 		SEQ_OPTS_PUTS("errors=continue");
1802 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1803 		SEQ_OPTS_PUTS("errors=panic");
1804 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1805 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1806 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1807 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1808 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1809 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1810 	if (sb->s_flags & MS_I_VERSION)
1811 		SEQ_OPTS_PUTS("i_version");
1812 	if (nodefs || sbi->s_stripe)
1813 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1814 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1815 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1816 			SEQ_OPTS_PUTS("data=journal");
1817 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1818 			SEQ_OPTS_PUTS("data=ordered");
1819 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1820 			SEQ_OPTS_PUTS("data=writeback");
1821 	}
1822 	if (nodefs ||
1823 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1824 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1825 			       sbi->s_inode_readahead_blks);
1826 
1827 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1828 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1829 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1830 	if (nodefs || sbi->s_max_dir_size_kb)
1831 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1832 
1833 	ext4_show_quota_options(seq, sb);
1834 	return 0;
1835 }
1836 
1837 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1838 {
1839 	return _ext4_show_options(seq, root->d_sb, 0);
1840 }
1841 
1842 static int options_seq_show(struct seq_file *seq, void *offset)
1843 {
1844 	struct super_block *sb = seq->private;
1845 	int rc;
1846 
1847 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1848 	rc = _ext4_show_options(seq, sb, 1);
1849 	seq_puts(seq, "\n");
1850 	return rc;
1851 }
1852 
1853 static int options_open_fs(struct inode *inode, struct file *file)
1854 {
1855 	return single_open(file, options_seq_show, PDE_DATA(inode));
1856 }
1857 
1858 static const struct file_operations ext4_seq_options_fops = {
1859 	.owner = THIS_MODULE,
1860 	.open = options_open_fs,
1861 	.read = seq_read,
1862 	.llseek = seq_lseek,
1863 	.release = single_release,
1864 };
1865 
1866 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1867 			    int read_only)
1868 {
1869 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1870 	int res = 0;
1871 
1872 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1873 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1874 			 "forcing read-only mode");
1875 		res = MS_RDONLY;
1876 	}
1877 	if (read_only)
1878 		goto done;
1879 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1880 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1881 			 "running e2fsck is recommended");
1882 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1883 		ext4_msg(sb, KERN_WARNING,
1884 			 "warning: mounting fs with errors, "
1885 			 "running e2fsck is recommended");
1886 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1887 		 le16_to_cpu(es->s_mnt_count) >=
1888 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1889 		ext4_msg(sb, KERN_WARNING,
1890 			 "warning: maximal mount count reached, "
1891 			 "running e2fsck is recommended");
1892 	else if (le32_to_cpu(es->s_checkinterval) &&
1893 		(le32_to_cpu(es->s_lastcheck) +
1894 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1895 		ext4_msg(sb, KERN_WARNING,
1896 			 "warning: checktime reached, "
1897 			 "running e2fsck is recommended");
1898 	if (!sbi->s_journal)
1899 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1900 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1901 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1902 	le16_add_cpu(&es->s_mnt_count, 1);
1903 	es->s_mtime = cpu_to_le32(get_seconds());
1904 	ext4_update_dynamic_rev(sb);
1905 	if (sbi->s_journal)
1906 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1907 
1908 	ext4_commit_super(sb, 1);
1909 done:
1910 	if (test_opt(sb, DEBUG))
1911 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1912 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1913 			sb->s_blocksize,
1914 			sbi->s_groups_count,
1915 			EXT4_BLOCKS_PER_GROUP(sb),
1916 			EXT4_INODES_PER_GROUP(sb),
1917 			sbi->s_mount_opt, sbi->s_mount_opt2);
1918 
1919 	cleancache_init_fs(sb);
1920 	return res;
1921 }
1922 
1923 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1924 {
1925 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1926 	struct flex_groups *new_groups;
1927 	int size;
1928 
1929 	if (!sbi->s_log_groups_per_flex)
1930 		return 0;
1931 
1932 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
1933 	if (size <= sbi->s_flex_groups_allocated)
1934 		return 0;
1935 
1936 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1937 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1938 	if (!new_groups) {
1939 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1940 			 size / (int) sizeof(struct flex_groups));
1941 		return -ENOMEM;
1942 	}
1943 
1944 	if (sbi->s_flex_groups) {
1945 		memcpy(new_groups, sbi->s_flex_groups,
1946 		       (sbi->s_flex_groups_allocated *
1947 			sizeof(struct flex_groups)));
1948 		ext4_kvfree(sbi->s_flex_groups);
1949 	}
1950 	sbi->s_flex_groups = new_groups;
1951 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1952 	return 0;
1953 }
1954 
1955 static int ext4_fill_flex_info(struct super_block *sb)
1956 {
1957 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1958 	struct ext4_group_desc *gdp = NULL;
1959 	ext4_group_t flex_group;
1960 	int i, err;
1961 
1962 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1963 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1964 		sbi->s_log_groups_per_flex = 0;
1965 		return 1;
1966 	}
1967 
1968 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1969 	if (err)
1970 		goto failed;
1971 
1972 	for (i = 0; i < sbi->s_groups_count; i++) {
1973 		gdp = ext4_get_group_desc(sb, i, NULL);
1974 
1975 		flex_group = ext4_flex_group(sbi, i);
1976 		atomic_add(ext4_free_inodes_count(sb, gdp),
1977 			   &sbi->s_flex_groups[flex_group].free_inodes);
1978 		atomic64_add(ext4_free_group_clusters(sb, gdp),
1979 			     &sbi->s_flex_groups[flex_group].free_clusters);
1980 		atomic_add(ext4_used_dirs_count(sb, gdp),
1981 			   &sbi->s_flex_groups[flex_group].used_dirs);
1982 	}
1983 
1984 	return 1;
1985 failed:
1986 	return 0;
1987 }
1988 
1989 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1990 				   struct ext4_group_desc *gdp)
1991 {
1992 	int offset;
1993 	__u16 crc = 0;
1994 	__le32 le_group = cpu_to_le32(block_group);
1995 
1996 	if ((sbi->s_es->s_feature_ro_compat &
1997 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1998 		/* Use new metadata_csum algorithm */
1999 		__le16 save_csum;
2000 		__u32 csum32;
2001 
2002 		save_csum = gdp->bg_checksum;
2003 		gdp->bg_checksum = 0;
2004 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2005 				     sizeof(le_group));
2006 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2007 				     sbi->s_desc_size);
2008 		gdp->bg_checksum = save_csum;
2009 
2010 		crc = csum32 & 0xFFFF;
2011 		goto out;
2012 	}
2013 
2014 	/* old crc16 code */
2015 	offset = offsetof(struct ext4_group_desc, bg_checksum);
2016 
2017 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2018 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2019 	crc = crc16(crc, (__u8 *)gdp, offset);
2020 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2021 	/* for checksum of struct ext4_group_desc do the rest...*/
2022 	if ((sbi->s_es->s_feature_incompat &
2023 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2024 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2025 		crc = crc16(crc, (__u8 *)gdp + offset,
2026 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2027 				offset);
2028 
2029 out:
2030 	return cpu_to_le16(crc);
2031 }
2032 
2033 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2034 				struct ext4_group_desc *gdp)
2035 {
2036 	if (ext4_has_group_desc_csum(sb) &&
2037 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2038 						      block_group, gdp)))
2039 		return 0;
2040 
2041 	return 1;
2042 }
2043 
2044 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2045 			      struct ext4_group_desc *gdp)
2046 {
2047 	if (!ext4_has_group_desc_csum(sb))
2048 		return;
2049 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2050 }
2051 
2052 /* Called at mount-time, super-block is locked */
2053 static int ext4_check_descriptors(struct super_block *sb,
2054 				  ext4_group_t *first_not_zeroed)
2055 {
2056 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2057 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2058 	ext4_fsblk_t last_block;
2059 	ext4_fsblk_t block_bitmap;
2060 	ext4_fsblk_t inode_bitmap;
2061 	ext4_fsblk_t inode_table;
2062 	int flexbg_flag = 0;
2063 	ext4_group_t i, grp = sbi->s_groups_count;
2064 
2065 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2066 		flexbg_flag = 1;
2067 
2068 	ext4_debug("Checking group descriptors");
2069 
2070 	for (i = 0; i < sbi->s_groups_count; i++) {
2071 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2072 
2073 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2074 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2075 		else
2076 			last_block = first_block +
2077 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2078 
2079 		if ((grp == sbi->s_groups_count) &&
2080 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2081 			grp = i;
2082 
2083 		block_bitmap = ext4_block_bitmap(sb, gdp);
2084 		if (block_bitmap < first_block || block_bitmap > last_block) {
2085 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2086 			       "Block bitmap for group %u not in group "
2087 			       "(block %llu)!", i, block_bitmap);
2088 			return 0;
2089 		}
2090 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2091 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2092 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2093 			       "Inode bitmap for group %u not in group "
2094 			       "(block %llu)!", i, inode_bitmap);
2095 			return 0;
2096 		}
2097 		inode_table = ext4_inode_table(sb, gdp);
2098 		if (inode_table < first_block ||
2099 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2100 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2101 			       "Inode table for group %u not in group "
2102 			       "(block %llu)!", i, inode_table);
2103 			return 0;
2104 		}
2105 		ext4_lock_group(sb, i);
2106 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2107 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2108 				 "Checksum for group %u failed (%u!=%u)",
2109 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2110 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2111 			if (!(sb->s_flags & MS_RDONLY)) {
2112 				ext4_unlock_group(sb, i);
2113 				return 0;
2114 			}
2115 		}
2116 		ext4_unlock_group(sb, i);
2117 		if (!flexbg_flag)
2118 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2119 	}
2120 	if (NULL != first_not_zeroed)
2121 		*first_not_zeroed = grp;
2122 
2123 	ext4_free_blocks_count_set(sbi->s_es,
2124 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2125 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2126 	return 1;
2127 }
2128 
2129 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2130  * the superblock) which were deleted from all directories, but held open by
2131  * a process at the time of a crash.  We walk the list and try to delete these
2132  * inodes at recovery time (only with a read-write filesystem).
2133  *
2134  * In order to keep the orphan inode chain consistent during traversal (in
2135  * case of crash during recovery), we link each inode into the superblock
2136  * orphan list_head and handle it the same way as an inode deletion during
2137  * normal operation (which journals the operations for us).
2138  *
2139  * We only do an iget() and an iput() on each inode, which is very safe if we
2140  * accidentally point at an in-use or already deleted inode.  The worst that
2141  * can happen in this case is that we get a "bit already cleared" message from
2142  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2143  * e2fsck was run on this filesystem, and it must have already done the orphan
2144  * inode cleanup for us, so we can safely abort without any further action.
2145  */
2146 static void ext4_orphan_cleanup(struct super_block *sb,
2147 				struct ext4_super_block *es)
2148 {
2149 	unsigned int s_flags = sb->s_flags;
2150 	int nr_orphans = 0, nr_truncates = 0;
2151 #ifdef CONFIG_QUOTA
2152 	int i;
2153 #endif
2154 	if (!es->s_last_orphan) {
2155 		jbd_debug(4, "no orphan inodes to clean up\n");
2156 		return;
2157 	}
2158 
2159 	if (bdev_read_only(sb->s_bdev)) {
2160 		ext4_msg(sb, KERN_ERR, "write access "
2161 			"unavailable, skipping orphan cleanup");
2162 		return;
2163 	}
2164 
2165 	/* Check if feature set would not allow a r/w mount */
2166 	if (!ext4_feature_set_ok(sb, 0)) {
2167 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2168 			 "unknown ROCOMPAT features");
2169 		return;
2170 	}
2171 
2172 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2173 		/* don't clear list on RO mount w/ errors */
2174 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2175 			jbd_debug(1, "Errors on filesystem, "
2176 				  "clearing orphan list.\n");
2177 			es->s_last_orphan = 0;
2178 		}
2179 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2180 		return;
2181 	}
2182 
2183 	if (s_flags & MS_RDONLY) {
2184 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2185 		sb->s_flags &= ~MS_RDONLY;
2186 	}
2187 #ifdef CONFIG_QUOTA
2188 	/* Needed for iput() to work correctly and not trash data */
2189 	sb->s_flags |= MS_ACTIVE;
2190 	/* Turn on quotas so that they are updated correctly */
2191 	for (i = 0; i < MAXQUOTAS; i++) {
2192 		if (EXT4_SB(sb)->s_qf_names[i]) {
2193 			int ret = ext4_quota_on_mount(sb, i);
2194 			if (ret < 0)
2195 				ext4_msg(sb, KERN_ERR,
2196 					"Cannot turn on journaled "
2197 					"quota: error %d", ret);
2198 		}
2199 	}
2200 #endif
2201 
2202 	while (es->s_last_orphan) {
2203 		struct inode *inode;
2204 
2205 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2206 		if (IS_ERR(inode)) {
2207 			es->s_last_orphan = 0;
2208 			break;
2209 		}
2210 
2211 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2212 		dquot_initialize(inode);
2213 		if (inode->i_nlink) {
2214 			if (test_opt(sb, DEBUG))
2215 				ext4_msg(sb, KERN_DEBUG,
2216 					"%s: truncating inode %lu to %lld bytes",
2217 					__func__, inode->i_ino, inode->i_size);
2218 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2219 				  inode->i_ino, inode->i_size);
2220 			mutex_lock(&inode->i_mutex);
2221 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2222 			ext4_truncate(inode);
2223 			mutex_unlock(&inode->i_mutex);
2224 			nr_truncates++;
2225 		} else {
2226 			if (test_opt(sb, DEBUG))
2227 				ext4_msg(sb, KERN_DEBUG,
2228 					"%s: deleting unreferenced inode %lu",
2229 					__func__, inode->i_ino);
2230 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2231 				  inode->i_ino);
2232 			nr_orphans++;
2233 		}
2234 		iput(inode);  /* The delete magic happens here! */
2235 	}
2236 
2237 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2238 
2239 	if (nr_orphans)
2240 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2241 		       PLURAL(nr_orphans));
2242 	if (nr_truncates)
2243 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2244 		       PLURAL(nr_truncates));
2245 #ifdef CONFIG_QUOTA
2246 	/* Turn quotas off */
2247 	for (i = 0; i < MAXQUOTAS; i++) {
2248 		if (sb_dqopt(sb)->files[i])
2249 			dquot_quota_off(sb, i);
2250 	}
2251 #endif
2252 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2253 }
2254 
2255 /*
2256  * Maximal extent format file size.
2257  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2258  * extent format containers, within a sector_t, and within i_blocks
2259  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2260  * so that won't be a limiting factor.
2261  *
2262  * However there is other limiting factor. We do store extents in the form
2263  * of starting block and length, hence the resulting length of the extent
2264  * covering maximum file size must fit into on-disk format containers as
2265  * well. Given that length is always by 1 unit bigger than max unit (because
2266  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2267  *
2268  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2269  */
2270 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2271 {
2272 	loff_t res;
2273 	loff_t upper_limit = MAX_LFS_FILESIZE;
2274 
2275 	/* small i_blocks in vfs inode? */
2276 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2277 		/*
2278 		 * CONFIG_LBDAF is not enabled implies the inode
2279 		 * i_block represent total blocks in 512 bytes
2280 		 * 32 == size of vfs inode i_blocks * 8
2281 		 */
2282 		upper_limit = (1LL << 32) - 1;
2283 
2284 		/* total blocks in file system block size */
2285 		upper_limit >>= (blkbits - 9);
2286 		upper_limit <<= blkbits;
2287 	}
2288 
2289 	/*
2290 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2291 	 * by one fs block, so ee_len can cover the extent of maximum file
2292 	 * size
2293 	 */
2294 	res = (1LL << 32) - 1;
2295 	res <<= blkbits;
2296 
2297 	/* Sanity check against vm- & vfs- imposed limits */
2298 	if (res > upper_limit)
2299 		res = upper_limit;
2300 
2301 	return res;
2302 }
2303 
2304 /*
2305  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2306  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2307  * We need to be 1 filesystem block less than the 2^48 sector limit.
2308  */
2309 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2310 {
2311 	loff_t res = EXT4_NDIR_BLOCKS;
2312 	int meta_blocks;
2313 	loff_t upper_limit;
2314 	/* This is calculated to be the largest file size for a dense, block
2315 	 * mapped file such that the file's total number of 512-byte sectors,
2316 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2317 	 *
2318 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2319 	 * number of 512-byte sectors of the file.
2320 	 */
2321 
2322 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2323 		/*
2324 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2325 		 * the inode i_block field represents total file blocks in
2326 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2327 		 */
2328 		upper_limit = (1LL << 32) - 1;
2329 
2330 		/* total blocks in file system block size */
2331 		upper_limit >>= (bits - 9);
2332 
2333 	} else {
2334 		/*
2335 		 * We use 48 bit ext4_inode i_blocks
2336 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2337 		 * represent total number of blocks in
2338 		 * file system block size
2339 		 */
2340 		upper_limit = (1LL << 48) - 1;
2341 
2342 	}
2343 
2344 	/* indirect blocks */
2345 	meta_blocks = 1;
2346 	/* double indirect blocks */
2347 	meta_blocks += 1 + (1LL << (bits-2));
2348 	/* tripple indirect blocks */
2349 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2350 
2351 	upper_limit -= meta_blocks;
2352 	upper_limit <<= bits;
2353 
2354 	res += 1LL << (bits-2);
2355 	res += 1LL << (2*(bits-2));
2356 	res += 1LL << (3*(bits-2));
2357 	res <<= bits;
2358 	if (res > upper_limit)
2359 		res = upper_limit;
2360 
2361 	if (res > MAX_LFS_FILESIZE)
2362 		res = MAX_LFS_FILESIZE;
2363 
2364 	return res;
2365 }
2366 
2367 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2368 				   ext4_fsblk_t logical_sb_block, int nr)
2369 {
2370 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2371 	ext4_group_t bg, first_meta_bg;
2372 	int has_super = 0;
2373 
2374 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2375 
2376 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2377 	    nr < first_meta_bg)
2378 		return logical_sb_block + nr + 1;
2379 	bg = sbi->s_desc_per_block * nr;
2380 	if (ext4_bg_has_super(sb, bg))
2381 		has_super = 1;
2382 
2383 	return (has_super + ext4_group_first_block_no(sb, bg));
2384 }
2385 
2386 /**
2387  * ext4_get_stripe_size: Get the stripe size.
2388  * @sbi: In memory super block info
2389  *
2390  * If we have specified it via mount option, then
2391  * use the mount option value. If the value specified at mount time is
2392  * greater than the blocks per group use the super block value.
2393  * If the super block value is greater than blocks per group return 0.
2394  * Allocator needs it be less than blocks per group.
2395  *
2396  */
2397 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2398 {
2399 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2400 	unsigned long stripe_width =
2401 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2402 	int ret;
2403 
2404 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2405 		ret = sbi->s_stripe;
2406 	else if (stripe_width <= sbi->s_blocks_per_group)
2407 		ret = stripe_width;
2408 	else if (stride <= sbi->s_blocks_per_group)
2409 		ret = stride;
2410 	else
2411 		ret = 0;
2412 
2413 	/*
2414 	 * If the stripe width is 1, this makes no sense and
2415 	 * we set it to 0 to turn off stripe handling code.
2416 	 */
2417 	if (ret <= 1)
2418 		ret = 0;
2419 
2420 	return ret;
2421 }
2422 
2423 /* sysfs supprt */
2424 
2425 struct ext4_attr {
2426 	struct attribute attr;
2427 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2428 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2429 			 const char *, size_t);
2430 	union {
2431 		int offset;
2432 		int deprecated_val;
2433 	} u;
2434 };
2435 
2436 static int parse_strtoull(const char *buf,
2437 		unsigned long long max, unsigned long long *value)
2438 {
2439 	int ret;
2440 
2441 	ret = kstrtoull(skip_spaces(buf), 0, value);
2442 	if (!ret && *value > max)
2443 		ret = -EINVAL;
2444 	return ret;
2445 }
2446 
2447 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2448 					      struct ext4_sb_info *sbi,
2449 					      char *buf)
2450 {
2451 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2452 		(s64) EXT4_C2B(sbi,
2453 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2454 }
2455 
2456 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2457 					 struct ext4_sb_info *sbi, char *buf)
2458 {
2459 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2460 
2461 	if (!sb->s_bdev->bd_part)
2462 		return snprintf(buf, PAGE_SIZE, "0\n");
2463 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2464 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2465 			 sbi->s_sectors_written_start) >> 1);
2466 }
2467 
2468 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2469 					  struct ext4_sb_info *sbi, char *buf)
2470 {
2471 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2472 
2473 	if (!sb->s_bdev->bd_part)
2474 		return snprintf(buf, PAGE_SIZE, "0\n");
2475 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2476 			(unsigned long long)(sbi->s_kbytes_written +
2477 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2478 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2479 }
2480 
2481 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2482 					  struct ext4_sb_info *sbi,
2483 					  const char *buf, size_t count)
2484 {
2485 	unsigned long t;
2486 	int ret;
2487 
2488 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2489 	if (ret)
2490 		return ret;
2491 
2492 	if (t && (!is_power_of_2(t) || t > 0x40000000))
2493 		return -EINVAL;
2494 
2495 	sbi->s_inode_readahead_blks = t;
2496 	return count;
2497 }
2498 
2499 static ssize_t sbi_ui_show(struct ext4_attr *a,
2500 			   struct ext4_sb_info *sbi, char *buf)
2501 {
2502 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2503 
2504 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2505 }
2506 
2507 static ssize_t sbi_ui_store(struct ext4_attr *a,
2508 			    struct ext4_sb_info *sbi,
2509 			    const char *buf, size_t count)
2510 {
2511 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2512 	unsigned long t;
2513 	int ret;
2514 
2515 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2516 	if (ret)
2517 		return ret;
2518 	*ui = t;
2519 	return count;
2520 }
2521 
2522 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2523 				  struct ext4_sb_info *sbi, char *buf)
2524 {
2525 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2526 		(unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2527 }
2528 
2529 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2530 				   struct ext4_sb_info *sbi,
2531 				   const char *buf, size_t count)
2532 {
2533 	unsigned long long val;
2534 	int ret;
2535 
2536 	if (parse_strtoull(buf, -1ULL, &val))
2537 		return -EINVAL;
2538 	ret = ext4_reserve_clusters(sbi, val);
2539 
2540 	return ret ? ret : count;
2541 }
2542 
2543 static ssize_t trigger_test_error(struct ext4_attr *a,
2544 				  struct ext4_sb_info *sbi,
2545 				  const char *buf, size_t count)
2546 {
2547 	int len = count;
2548 
2549 	if (!capable(CAP_SYS_ADMIN))
2550 		return -EPERM;
2551 
2552 	if (len && buf[len-1] == '\n')
2553 		len--;
2554 
2555 	if (len)
2556 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2557 	return count;
2558 }
2559 
2560 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2561 				   struct ext4_sb_info *sbi, char *buf)
2562 {
2563 	return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2564 }
2565 
2566 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2567 static struct ext4_attr ext4_attr_##_name = {			\
2568 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2569 	.show	= _show,					\
2570 	.store	= _store,					\
2571 	.u = {							\
2572 		.offset = offsetof(struct ext4_sb_info, _elname),\
2573 	},							\
2574 }
2575 #define EXT4_ATTR(name, mode, show, store) \
2576 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2577 
2578 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2579 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2580 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2581 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2582 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2583 #define ATTR_LIST(name) &ext4_attr_##name.attr
2584 #define EXT4_DEPRECATED_ATTR(_name, _val)	\
2585 static struct ext4_attr ext4_attr_##_name = {			\
2586 	.attr = {.name = __stringify(_name), .mode = 0444 },	\
2587 	.show	= sbi_deprecated_show,				\
2588 	.u = {							\
2589 		.deprecated_val = _val,				\
2590 	},							\
2591 }
2592 
2593 EXT4_RO_ATTR(delayed_allocation_blocks);
2594 EXT4_RO_ATTR(session_write_kbytes);
2595 EXT4_RO_ATTR(lifetime_write_kbytes);
2596 EXT4_RW_ATTR(reserved_clusters);
2597 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2598 		 inode_readahead_blks_store, s_inode_readahead_blks);
2599 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2600 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2601 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2602 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2603 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2604 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2605 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2606 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2607 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2608 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2609 
2610 static struct attribute *ext4_attrs[] = {
2611 	ATTR_LIST(delayed_allocation_blocks),
2612 	ATTR_LIST(session_write_kbytes),
2613 	ATTR_LIST(lifetime_write_kbytes),
2614 	ATTR_LIST(reserved_clusters),
2615 	ATTR_LIST(inode_readahead_blks),
2616 	ATTR_LIST(inode_goal),
2617 	ATTR_LIST(mb_stats),
2618 	ATTR_LIST(mb_max_to_scan),
2619 	ATTR_LIST(mb_min_to_scan),
2620 	ATTR_LIST(mb_order2_req),
2621 	ATTR_LIST(mb_stream_req),
2622 	ATTR_LIST(mb_group_prealloc),
2623 	ATTR_LIST(max_writeback_mb_bump),
2624 	ATTR_LIST(extent_max_zeroout_kb),
2625 	ATTR_LIST(trigger_fs_error),
2626 	NULL,
2627 };
2628 
2629 /* Features this copy of ext4 supports */
2630 EXT4_INFO_ATTR(lazy_itable_init);
2631 EXT4_INFO_ATTR(batched_discard);
2632 EXT4_INFO_ATTR(meta_bg_resize);
2633 
2634 static struct attribute *ext4_feat_attrs[] = {
2635 	ATTR_LIST(lazy_itable_init),
2636 	ATTR_LIST(batched_discard),
2637 	ATTR_LIST(meta_bg_resize),
2638 	NULL,
2639 };
2640 
2641 static ssize_t ext4_attr_show(struct kobject *kobj,
2642 			      struct attribute *attr, char *buf)
2643 {
2644 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2645 						s_kobj);
2646 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2647 
2648 	return a->show ? a->show(a, sbi, buf) : 0;
2649 }
2650 
2651 static ssize_t ext4_attr_store(struct kobject *kobj,
2652 			       struct attribute *attr,
2653 			       const char *buf, size_t len)
2654 {
2655 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2656 						s_kobj);
2657 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2658 
2659 	return a->store ? a->store(a, sbi, buf, len) : 0;
2660 }
2661 
2662 static void ext4_sb_release(struct kobject *kobj)
2663 {
2664 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2665 						s_kobj);
2666 	complete(&sbi->s_kobj_unregister);
2667 }
2668 
2669 static const struct sysfs_ops ext4_attr_ops = {
2670 	.show	= ext4_attr_show,
2671 	.store	= ext4_attr_store,
2672 };
2673 
2674 static struct kobj_type ext4_ktype = {
2675 	.default_attrs	= ext4_attrs,
2676 	.sysfs_ops	= &ext4_attr_ops,
2677 	.release	= ext4_sb_release,
2678 };
2679 
2680 static void ext4_feat_release(struct kobject *kobj)
2681 {
2682 	complete(&ext4_feat->f_kobj_unregister);
2683 }
2684 
2685 static struct kobj_type ext4_feat_ktype = {
2686 	.default_attrs	= ext4_feat_attrs,
2687 	.sysfs_ops	= &ext4_attr_ops,
2688 	.release	= ext4_feat_release,
2689 };
2690 
2691 /*
2692  * Check whether this filesystem can be mounted based on
2693  * the features present and the RDONLY/RDWR mount requested.
2694  * Returns 1 if this filesystem can be mounted as requested,
2695  * 0 if it cannot be.
2696  */
2697 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2698 {
2699 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2700 		ext4_msg(sb, KERN_ERR,
2701 			"Couldn't mount because of "
2702 			"unsupported optional features (%x)",
2703 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2704 			~EXT4_FEATURE_INCOMPAT_SUPP));
2705 		return 0;
2706 	}
2707 
2708 	if (readonly)
2709 		return 1;
2710 
2711 	/* Check that feature set is OK for a read-write mount */
2712 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2713 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2714 			 "unsupported optional features (%x)",
2715 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2716 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2717 		return 0;
2718 	}
2719 	/*
2720 	 * Large file size enabled file system can only be mounted
2721 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2722 	 */
2723 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2724 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2725 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2726 				 "cannot be mounted RDWR without "
2727 				 "CONFIG_LBDAF");
2728 			return 0;
2729 		}
2730 	}
2731 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2732 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2733 		ext4_msg(sb, KERN_ERR,
2734 			 "Can't support bigalloc feature without "
2735 			 "extents feature\n");
2736 		return 0;
2737 	}
2738 
2739 #ifndef CONFIG_QUOTA
2740 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2741 	    !readonly) {
2742 		ext4_msg(sb, KERN_ERR,
2743 			 "Filesystem with quota feature cannot be mounted RDWR "
2744 			 "without CONFIG_QUOTA");
2745 		return 0;
2746 	}
2747 #endif  /* CONFIG_QUOTA */
2748 	return 1;
2749 }
2750 
2751 /*
2752  * This function is called once a day if we have errors logged
2753  * on the file system
2754  */
2755 static void print_daily_error_info(unsigned long arg)
2756 {
2757 	struct super_block *sb = (struct super_block *) arg;
2758 	struct ext4_sb_info *sbi;
2759 	struct ext4_super_block *es;
2760 
2761 	sbi = EXT4_SB(sb);
2762 	es = sbi->s_es;
2763 
2764 	if (es->s_error_count)
2765 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2766 			 le32_to_cpu(es->s_error_count));
2767 	if (es->s_first_error_time) {
2768 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2769 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2770 		       (int) sizeof(es->s_first_error_func),
2771 		       es->s_first_error_func,
2772 		       le32_to_cpu(es->s_first_error_line));
2773 		if (es->s_first_error_ino)
2774 			printk(": inode %u",
2775 			       le32_to_cpu(es->s_first_error_ino));
2776 		if (es->s_first_error_block)
2777 			printk(": block %llu", (unsigned long long)
2778 			       le64_to_cpu(es->s_first_error_block));
2779 		printk("\n");
2780 	}
2781 	if (es->s_last_error_time) {
2782 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2783 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2784 		       (int) sizeof(es->s_last_error_func),
2785 		       es->s_last_error_func,
2786 		       le32_to_cpu(es->s_last_error_line));
2787 		if (es->s_last_error_ino)
2788 			printk(": inode %u",
2789 			       le32_to_cpu(es->s_last_error_ino));
2790 		if (es->s_last_error_block)
2791 			printk(": block %llu", (unsigned long long)
2792 			       le64_to_cpu(es->s_last_error_block));
2793 		printk("\n");
2794 	}
2795 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2796 }
2797 
2798 /* Find next suitable group and run ext4_init_inode_table */
2799 static int ext4_run_li_request(struct ext4_li_request *elr)
2800 {
2801 	struct ext4_group_desc *gdp = NULL;
2802 	ext4_group_t group, ngroups;
2803 	struct super_block *sb;
2804 	unsigned long timeout = 0;
2805 	int ret = 0;
2806 
2807 	sb = elr->lr_super;
2808 	ngroups = EXT4_SB(sb)->s_groups_count;
2809 
2810 	sb_start_write(sb);
2811 	for (group = elr->lr_next_group; group < ngroups; group++) {
2812 		gdp = ext4_get_group_desc(sb, group, NULL);
2813 		if (!gdp) {
2814 			ret = 1;
2815 			break;
2816 		}
2817 
2818 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2819 			break;
2820 	}
2821 
2822 	if (group >= ngroups)
2823 		ret = 1;
2824 
2825 	if (!ret) {
2826 		timeout = jiffies;
2827 		ret = ext4_init_inode_table(sb, group,
2828 					    elr->lr_timeout ? 0 : 1);
2829 		if (elr->lr_timeout == 0) {
2830 			timeout = (jiffies - timeout) *
2831 				  elr->lr_sbi->s_li_wait_mult;
2832 			elr->lr_timeout = timeout;
2833 		}
2834 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2835 		elr->lr_next_group = group + 1;
2836 	}
2837 	sb_end_write(sb);
2838 
2839 	return ret;
2840 }
2841 
2842 /*
2843  * Remove lr_request from the list_request and free the
2844  * request structure. Should be called with li_list_mtx held
2845  */
2846 static void ext4_remove_li_request(struct ext4_li_request *elr)
2847 {
2848 	struct ext4_sb_info *sbi;
2849 
2850 	if (!elr)
2851 		return;
2852 
2853 	sbi = elr->lr_sbi;
2854 
2855 	list_del(&elr->lr_request);
2856 	sbi->s_li_request = NULL;
2857 	kfree(elr);
2858 }
2859 
2860 static void ext4_unregister_li_request(struct super_block *sb)
2861 {
2862 	mutex_lock(&ext4_li_mtx);
2863 	if (!ext4_li_info) {
2864 		mutex_unlock(&ext4_li_mtx);
2865 		return;
2866 	}
2867 
2868 	mutex_lock(&ext4_li_info->li_list_mtx);
2869 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2870 	mutex_unlock(&ext4_li_info->li_list_mtx);
2871 	mutex_unlock(&ext4_li_mtx);
2872 }
2873 
2874 static struct task_struct *ext4_lazyinit_task;
2875 
2876 /*
2877  * This is the function where ext4lazyinit thread lives. It walks
2878  * through the request list searching for next scheduled filesystem.
2879  * When such a fs is found, run the lazy initialization request
2880  * (ext4_rn_li_request) and keep track of the time spend in this
2881  * function. Based on that time we compute next schedule time of
2882  * the request. When walking through the list is complete, compute
2883  * next waking time and put itself into sleep.
2884  */
2885 static int ext4_lazyinit_thread(void *arg)
2886 {
2887 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2888 	struct list_head *pos, *n;
2889 	struct ext4_li_request *elr;
2890 	unsigned long next_wakeup, cur;
2891 
2892 	BUG_ON(NULL == eli);
2893 
2894 cont_thread:
2895 	while (true) {
2896 		next_wakeup = MAX_JIFFY_OFFSET;
2897 
2898 		mutex_lock(&eli->li_list_mtx);
2899 		if (list_empty(&eli->li_request_list)) {
2900 			mutex_unlock(&eli->li_list_mtx);
2901 			goto exit_thread;
2902 		}
2903 
2904 		list_for_each_safe(pos, n, &eli->li_request_list) {
2905 			elr = list_entry(pos, struct ext4_li_request,
2906 					 lr_request);
2907 
2908 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2909 				if (ext4_run_li_request(elr) != 0) {
2910 					/* error, remove the lazy_init job */
2911 					ext4_remove_li_request(elr);
2912 					continue;
2913 				}
2914 			}
2915 
2916 			if (time_before(elr->lr_next_sched, next_wakeup))
2917 				next_wakeup = elr->lr_next_sched;
2918 		}
2919 		mutex_unlock(&eli->li_list_mtx);
2920 
2921 		try_to_freeze();
2922 
2923 		cur = jiffies;
2924 		if ((time_after_eq(cur, next_wakeup)) ||
2925 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2926 			cond_resched();
2927 			continue;
2928 		}
2929 
2930 		schedule_timeout_interruptible(next_wakeup - cur);
2931 
2932 		if (kthread_should_stop()) {
2933 			ext4_clear_request_list();
2934 			goto exit_thread;
2935 		}
2936 	}
2937 
2938 exit_thread:
2939 	/*
2940 	 * It looks like the request list is empty, but we need
2941 	 * to check it under the li_list_mtx lock, to prevent any
2942 	 * additions into it, and of course we should lock ext4_li_mtx
2943 	 * to atomically free the list and ext4_li_info, because at
2944 	 * this point another ext4 filesystem could be registering
2945 	 * new one.
2946 	 */
2947 	mutex_lock(&ext4_li_mtx);
2948 	mutex_lock(&eli->li_list_mtx);
2949 	if (!list_empty(&eli->li_request_list)) {
2950 		mutex_unlock(&eli->li_list_mtx);
2951 		mutex_unlock(&ext4_li_mtx);
2952 		goto cont_thread;
2953 	}
2954 	mutex_unlock(&eli->li_list_mtx);
2955 	kfree(ext4_li_info);
2956 	ext4_li_info = NULL;
2957 	mutex_unlock(&ext4_li_mtx);
2958 
2959 	return 0;
2960 }
2961 
2962 static void ext4_clear_request_list(void)
2963 {
2964 	struct list_head *pos, *n;
2965 	struct ext4_li_request *elr;
2966 
2967 	mutex_lock(&ext4_li_info->li_list_mtx);
2968 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2969 		elr = list_entry(pos, struct ext4_li_request,
2970 				 lr_request);
2971 		ext4_remove_li_request(elr);
2972 	}
2973 	mutex_unlock(&ext4_li_info->li_list_mtx);
2974 }
2975 
2976 static int ext4_run_lazyinit_thread(void)
2977 {
2978 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2979 					 ext4_li_info, "ext4lazyinit");
2980 	if (IS_ERR(ext4_lazyinit_task)) {
2981 		int err = PTR_ERR(ext4_lazyinit_task);
2982 		ext4_clear_request_list();
2983 		kfree(ext4_li_info);
2984 		ext4_li_info = NULL;
2985 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2986 				 "initialization thread\n",
2987 				 err);
2988 		return err;
2989 	}
2990 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2991 	return 0;
2992 }
2993 
2994 /*
2995  * Check whether it make sense to run itable init. thread or not.
2996  * If there is at least one uninitialized inode table, return
2997  * corresponding group number, else the loop goes through all
2998  * groups and return total number of groups.
2999  */
3000 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3001 {
3002 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3003 	struct ext4_group_desc *gdp = NULL;
3004 
3005 	for (group = 0; group < ngroups; group++) {
3006 		gdp = ext4_get_group_desc(sb, group, NULL);
3007 		if (!gdp)
3008 			continue;
3009 
3010 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3011 			break;
3012 	}
3013 
3014 	return group;
3015 }
3016 
3017 static int ext4_li_info_new(void)
3018 {
3019 	struct ext4_lazy_init *eli = NULL;
3020 
3021 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3022 	if (!eli)
3023 		return -ENOMEM;
3024 
3025 	INIT_LIST_HEAD(&eli->li_request_list);
3026 	mutex_init(&eli->li_list_mtx);
3027 
3028 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3029 
3030 	ext4_li_info = eli;
3031 
3032 	return 0;
3033 }
3034 
3035 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3036 					    ext4_group_t start)
3037 {
3038 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3039 	struct ext4_li_request *elr;
3040 	unsigned long rnd;
3041 
3042 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3043 	if (!elr)
3044 		return NULL;
3045 
3046 	elr->lr_super = sb;
3047 	elr->lr_sbi = sbi;
3048 	elr->lr_next_group = start;
3049 
3050 	/*
3051 	 * Randomize first schedule time of the request to
3052 	 * spread the inode table initialization requests
3053 	 * better.
3054 	 */
3055 	get_random_bytes(&rnd, sizeof(rnd));
3056 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
3057 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3058 
3059 	return elr;
3060 }
3061 
3062 int ext4_register_li_request(struct super_block *sb,
3063 			     ext4_group_t first_not_zeroed)
3064 {
3065 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3066 	struct ext4_li_request *elr = NULL;
3067 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3068 	int ret = 0;
3069 
3070 	mutex_lock(&ext4_li_mtx);
3071 	if (sbi->s_li_request != NULL) {
3072 		/*
3073 		 * Reset timeout so it can be computed again, because
3074 		 * s_li_wait_mult might have changed.
3075 		 */
3076 		sbi->s_li_request->lr_timeout = 0;
3077 		goto out;
3078 	}
3079 
3080 	if (first_not_zeroed == ngroups ||
3081 	    (sb->s_flags & MS_RDONLY) ||
3082 	    !test_opt(sb, INIT_INODE_TABLE))
3083 		goto out;
3084 
3085 	elr = ext4_li_request_new(sb, first_not_zeroed);
3086 	if (!elr) {
3087 		ret = -ENOMEM;
3088 		goto out;
3089 	}
3090 
3091 	if (NULL == ext4_li_info) {
3092 		ret = ext4_li_info_new();
3093 		if (ret)
3094 			goto out;
3095 	}
3096 
3097 	mutex_lock(&ext4_li_info->li_list_mtx);
3098 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3099 	mutex_unlock(&ext4_li_info->li_list_mtx);
3100 
3101 	sbi->s_li_request = elr;
3102 	/*
3103 	 * set elr to NULL here since it has been inserted to
3104 	 * the request_list and the removal and free of it is
3105 	 * handled by ext4_clear_request_list from now on.
3106 	 */
3107 	elr = NULL;
3108 
3109 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3110 		ret = ext4_run_lazyinit_thread();
3111 		if (ret)
3112 			goto out;
3113 	}
3114 out:
3115 	mutex_unlock(&ext4_li_mtx);
3116 	if (ret)
3117 		kfree(elr);
3118 	return ret;
3119 }
3120 
3121 /*
3122  * We do not need to lock anything since this is called on
3123  * module unload.
3124  */
3125 static void ext4_destroy_lazyinit_thread(void)
3126 {
3127 	/*
3128 	 * If thread exited earlier
3129 	 * there's nothing to be done.
3130 	 */
3131 	if (!ext4_li_info || !ext4_lazyinit_task)
3132 		return;
3133 
3134 	kthread_stop(ext4_lazyinit_task);
3135 }
3136 
3137 static int set_journal_csum_feature_set(struct super_block *sb)
3138 {
3139 	int ret = 1;
3140 	int compat, incompat;
3141 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3142 
3143 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3144 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3145 		/* journal checksum v2 */
3146 		compat = 0;
3147 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3148 	} else {
3149 		/* journal checksum v1 */
3150 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3151 		incompat = 0;
3152 	}
3153 
3154 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3155 		ret = jbd2_journal_set_features(sbi->s_journal,
3156 				compat, 0,
3157 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3158 				incompat);
3159 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3160 		ret = jbd2_journal_set_features(sbi->s_journal,
3161 				compat, 0,
3162 				incompat);
3163 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3164 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3165 	} else {
3166 		jbd2_journal_clear_features(sbi->s_journal,
3167 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3168 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3169 				JBD2_FEATURE_INCOMPAT_CSUM_V2);
3170 	}
3171 
3172 	return ret;
3173 }
3174 
3175 /*
3176  * Note: calculating the overhead so we can be compatible with
3177  * historical BSD practice is quite difficult in the face of
3178  * clusters/bigalloc.  This is because multiple metadata blocks from
3179  * different block group can end up in the same allocation cluster.
3180  * Calculating the exact overhead in the face of clustered allocation
3181  * requires either O(all block bitmaps) in memory or O(number of block
3182  * groups**2) in time.  We will still calculate the superblock for
3183  * older file systems --- and if we come across with a bigalloc file
3184  * system with zero in s_overhead_clusters the estimate will be close to
3185  * correct especially for very large cluster sizes --- but for newer
3186  * file systems, it's better to calculate this figure once at mkfs
3187  * time, and store it in the superblock.  If the superblock value is
3188  * present (even for non-bigalloc file systems), we will use it.
3189  */
3190 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3191 			  char *buf)
3192 {
3193 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3194 	struct ext4_group_desc	*gdp;
3195 	ext4_fsblk_t		first_block, last_block, b;
3196 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3197 	int			s, j, count = 0;
3198 
3199 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3200 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3201 			sbi->s_itb_per_group + 2);
3202 
3203 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3204 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3205 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3206 	for (i = 0; i < ngroups; i++) {
3207 		gdp = ext4_get_group_desc(sb, i, NULL);
3208 		b = ext4_block_bitmap(sb, gdp);
3209 		if (b >= first_block && b <= last_block) {
3210 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3211 			count++;
3212 		}
3213 		b = ext4_inode_bitmap(sb, gdp);
3214 		if (b >= first_block && b <= last_block) {
3215 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3216 			count++;
3217 		}
3218 		b = ext4_inode_table(sb, gdp);
3219 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3220 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3221 				int c = EXT4_B2C(sbi, b - first_block);
3222 				ext4_set_bit(c, buf);
3223 				count++;
3224 			}
3225 		if (i != grp)
3226 			continue;
3227 		s = 0;
3228 		if (ext4_bg_has_super(sb, grp)) {
3229 			ext4_set_bit(s++, buf);
3230 			count++;
3231 		}
3232 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3233 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3234 			count++;
3235 		}
3236 	}
3237 	if (!count)
3238 		return 0;
3239 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3240 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3241 }
3242 
3243 /*
3244  * Compute the overhead and stash it in sbi->s_overhead
3245  */
3246 int ext4_calculate_overhead(struct super_block *sb)
3247 {
3248 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3249 	struct ext4_super_block *es = sbi->s_es;
3250 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3251 	ext4_fsblk_t overhead = 0;
3252 	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3253 
3254 	if (!buf)
3255 		return -ENOMEM;
3256 
3257 	/*
3258 	 * Compute the overhead (FS structures).  This is constant
3259 	 * for a given filesystem unless the number of block groups
3260 	 * changes so we cache the previous value until it does.
3261 	 */
3262 
3263 	/*
3264 	 * All of the blocks before first_data_block are overhead
3265 	 */
3266 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3267 
3268 	/*
3269 	 * Add the overhead found in each block group
3270 	 */
3271 	for (i = 0; i < ngroups; i++) {
3272 		int blks;
3273 
3274 		blks = count_overhead(sb, i, buf);
3275 		overhead += blks;
3276 		if (blks)
3277 			memset(buf, 0, PAGE_SIZE);
3278 		cond_resched();
3279 	}
3280 	/* Add the journal blocks as well */
3281 	if (sbi->s_journal)
3282 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3283 
3284 	sbi->s_overhead = overhead;
3285 	smp_wmb();
3286 	free_page((unsigned long) buf);
3287 	return 0;
3288 }
3289 
3290 
3291 static ext4_fsblk_t ext4_calculate_resv_clusters(struct ext4_sb_info *sbi)
3292 {
3293 	ext4_fsblk_t resv_clusters;
3294 
3295 	/*
3296 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3297 	 * This should cover the situations where we can not afford to run
3298 	 * out of space like for example punch hole, or converting
3299 	 * uninitialized extents in delalloc path. In most cases such
3300 	 * allocation would require 1, or 2 blocks, higher numbers are
3301 	 * very rare.
3302 	 */
3303 	resv_clusters = ext4_blocks_count(sbi->s_es) >> sbi->s_cluster_bits;
3304 
3305 	do_div(resv_clusters, 50);
3306 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3307 
3308 	return resv_clusters;
3309 }
3310 
3311 
3312 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3313 {
3314 	ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3315 				sbi->s_cluster_bits;
3316 
3317 	if (count >= clusters)
3318 		return -EINVAL;
3319 
3320 	atomic64_set(&sbi->s_resv_clusters, count);
3321 	return 0;
3322 }
3323 
3324 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3325 {
3326 	char *orig_data = kstrdup(data, GFP_KERNEL);
3327 	struct buffer_head *bh;
3328 	struct ext4_super_block *es = NULL;
3329 	struct ext4_sb_info *sbi;
3330 	ext4_fsblk_t block;
3331 	ext4_fsblk_t sb_block = get_sb_block(&data);
3332 	ext4_fsblk_t logical_sb_block;
3333 	unsigned long offset = 0;
3334 	unsigned long journal_devnum = 0;
3335 	unsigned long def_mount_opts;
3336 	struct inode *root;
3337 	char *cp;
3338 	const char *descr;
3339 	int ret = -ENOMEM;
3340 	int blocksize, clustersize;
3341 	unsigned int db_count;
3342 	unsigned int i;
3343 	int needs_recovery, has_huge_files, has_bigalloc;
3344 	__u64 blocks_count;
3345 	int err = 0;
3346 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3347 	ext4_group_t first_not_zeroed;
3348 
3349 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3350 	if (!sbi)
3351 		goto out_free_orig;
3352 
3353 	sbi->s_blockgroup_lock =
3354 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3355 	if (!sbi->s_blockgroup_lock) {
3356 		kfree(sbi);
3357 		goto out_free_orig;
3358 	}
3359 	sb->s_fs_info = sbi;
3360 	sbi->s_sb = sb;
3361 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3362 	sbi->s_sb_block = sb_block;
3363 	if (sb->s_bdev->bd_part)
3364 		sbi->s_sectors_written_start =
3365 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3366 
3367 	/* Cleanup superblock name */
3368 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3369 		*cp = '!';
3370 
3371 	/* -EINVAL is default */
3372 	ret = -EINVAL;
3373 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3374 	if (!blocksize) {
3375 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3376 		goto out_fail;
3377 	}
3378 
3379 	/*
3380 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3381 	 * block sizes.  We need to calculate the offset from buffer start.
3382 	 */
3383 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3384 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3385 		offset = do_div(logical_sb_block, blocksize);
3386 	} else {
3387 		logical_sb_block = sb_block;
3388 	}
3389 
3390 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3391 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3392 		goto out_fail;
3393 	}
3394 	/*
3395 	 * Note: s_es must be initialized as soon as possible because
3396 	 *       some ext4 macro-instructions depend on its value
3397 	 */
3398 	es = (struct ext4_super_block *) (bh->b_data + offset);
3399 	sbi->s_es = es;
3400 	sb->s_magic = le16_to_cpu(es->s_magic);
3401 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3402 		goto cantfind_ext4;
3403 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3404 
3405 	/* Warn if metadata_csum and gdt_csum are both set. */
3406 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3407 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3408 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3409 		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3410 			     "redundant flags; please run fsck.");
3411 
3412 	/* Check for a known checksum algorithm */
3413 	if (!ext4_verify_csum_type(sb, es)) {
3414 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3415 			 "unknown checksum algorithm.");
3416 		silent = 1;
3417 		goto cantfind_ext4;
3418 	}
3419 
3420 	/* Load the checksum driver */
3421 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3422 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3423 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3424 		if (IS_ERR(sbi->s_chksum_driver)) {
3425 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3426 			ret = PTR_ERR(sbi->s_chksum_driver);
3427 			sbi->s_chksum_driver = NULL;
3428 			goto failed_mount;
3429 		}
3430 	}
3431 
3432 	/* Check superblock checksum */
3433 	if (!ext4_superblock_csum_verify(sb, es)) {
3434 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3435 			 "invalid superblock checksum.  Run e2fsck?");
3436 		silent = 1;
3437 		goto cantfind_ext4;
3438 	}
3439 
3440 	/* Precompute checksum seed for all metadata */
3441 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3442 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3443 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3444 					       sizeof(es->s_uuid));
3445 
3446 	/* Set defaults before we parse the mount options */
3447 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3448 	set_opt(sb, INIT_INODE_TABLE);
3449 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3450 		set_opt(sb, DEBUG);
3451 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3452 		set_opt(sb, GRPID);
3453 	if (def_mount_opts & EXT4_DEFM_UID16)
3454 		set_opt(sb, NO_UID32);
3455 	/* xattr user namespace & acls are now defaulted on */
3456 	set_opt(sb, XATTR_USER);
3457 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3458 	set_opt(sb, POSIX_ACL);
3459 #endif
3460 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3461 		set_opt(sb, JOURNAL_DATA);
3462 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3463 		set_opt(sb, ORDERED_DATA);
3464 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3465 		set_opt(sb, WRITEBACK_DATA);
3466 
3467 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3468 		set_opt(sb, ERRORS_PANIC);
3469 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3470 		set_opt(sb, ERRORS_CONT);
3471 	else
3472 		set_opt(sb, ERRORS_RO);
3473 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3474 		set_opt(sb, BLOCK_VALIDITY);
3475 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3476 		set_opt(sb, DISCARD);
3477 
3478 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3479 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3480 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3481 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3482 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3483 
3484 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3485 		set_opt(sb, BARRIER);
3486 
3487 	/*
3488 	 * enable delayed allocation by default
3489 	 * Use -o nodelalloc to turn it off
3490 	 */
3491 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3492 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3493 		set_opt(sb, DELALLOC);
3494 
3495 	/*
3496 	 * set default s_li_wait_mult for lazyinit, for the case there is
3497 	 * no mount option specified.
3498 	 */
3499 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3500 
3501 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3502 			   &journal_devnum, &journal_ioprio, 0)) {
3503 		ext4_msg(sb, KERN_WARNING,
3504 			 "failed to parse options in superblock: %s",
3505 			 sbi->s_es->s_mount_opts);
3506 	}
3507 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3508 	if (!parse_options((char *) data, sb, &journal_devnum,
3509 			   &journal_ioprio, 0))
3510 		goto failed_mount;
3511 
3512 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3513 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3514 			    "with data=journal disables delayed "
3515 			    "allocation and O_DIRECT support!\n");
3516 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3517 			ext4_msg(sb, KERN_ERR, "can't mount with "
3518 				 "both data=journal and delalloc");
3519 			goto failed_mount;
3520 		}
3521 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3522 			ext4_msg(sb, KERN_ERR, "can't mount with "
3523 				 "both data=journal and dioread_nolock");
3524 			goto failed_mount;
3525 		}
3526 		if (test_opt(sb, DELALLOC))
3527 			clear_opt(sb, DELALLOC);
3528 	}
3529 
3530 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3531 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3532 
3533 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3534 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3535 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3536 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3537 		ext4_msg(sb, KERN_WARNING,
3538 		       "feature flags set on rev 0 fs, "
3539 		       "running e2fsck is recommended");
3540 
3541 	if (IS_EXT2_SB(sb)) {
3542 		if (ext2_feature_set_ok(sb))
3543 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3544 				 "using the ext4 subsystem");
3545 		else {
3546 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3547 				 "to feature incompatibilities");
3548 			goto failed_mount;
3549 		}
3550 	}
3551 
3552 	if (IS_EXT3_SB(sb)) {
3553 		if (ext3_feature_set_ok(sb))
3554 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3555 				 "using the ext4 subsystem");
3556 		else {
3557 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3558 				 "to feature incompatibilities");
3559 			goto failed_mount;
3560 		}
3561 	}
3562 
3563 	/*
3564 	 * Check feature flags regardless of the revision level, since we
3565 	 * previously didn't change the revision level when setting the flags,
3566 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3567 	 */
3568 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3569 		goto failed_mount;
3570 
3571 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3572 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3573 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3574 		ext4_msg(sb, KERN_ERR,
3575 		       "Unsupported filesystem blocksize %d", blocksize);
3576 		goto failed_mount;
3577 	}
3578 
3579 	if (sb->s_blocksize != blocksize) {
3580 		/* Validate the filesystem blocksize */
3581 		if (!sb_set_blocksize(sb, blocksize)) {
3582 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3583 					blocksize);
3584 			goto failed_mount;
3585 		}
3586 
3587 		brelse(bh);
3588 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3589 		offset = do_div(logical_sb_block, blocksize);
3590 		bh = sb_bread(sb, logical_sb_block);
3591 		if (!bh) {
3592 			ext4_msg(sb, KERN_ERR,
3593 			       "Can't read superblock on 2nd try");
3594 			goto failed_mount;
3595 		}
3596 		es = (struct ext4_super_block *)(bh->b_data + offset);
3597 		sbi->s_es = es;
3598 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3599 			ext4_msg(sb, KERN_ERR,
3600 			       "Magic mismatch, very weird!");
3601 			goto failed_mount;
3602 		}
3603 	}
3604 
3605 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3606 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3607 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3608 						      has_huge_files);
3609 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3610 
3611 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3612 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3613 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3614 	} else {
3615 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3616 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3617 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3618 		    (!is_power_of_2(sbi->s_inode_size)) ||
3619 		    (sbi->s_inode_size > blocksize)) {
3620 			ext4_msg(sb, KERN_ERR,
3621 			       "unsupported inode size: %d",
3622 			       sbi->s_inode_size);
3623 			goto failed_mount;
3624 		}
3625 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3626 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3627 	}
3628 
3629 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3630 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3631 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3632 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3633 		    !is_power_of_2(sbi->s_desc_size)) {
3634 			ext4_msg(sb, KERN_ERR,
3635 			       "unsupported descriptor size %lu",
3636 			       sbi->s_desc_size);
3637 			goto failed_mount;
3638 		}
3639 	} else
3640 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3641 
3642 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3643 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3644 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3645 		goto cantfind_ext4;
3646 
3647 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3648 	if (sbi->s_inodes_per_block == 0)
3649 		goto cantfind_ext4;
3650 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3651 					sbi->s_inodes_per_block;
3652 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3653 	sbi->s_sbh = bh;
3654 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3655 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3656 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3657 
3658 	for (i = 0; i < 4; i++)
3659 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3660 	sbi->s_def_hash_version = es->s_def_hash_version;
3661 	i = le32_to_cpu(es->s_flags);
3662 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3663 		sbi->s_hash_unsigned = 3;
3664 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3665 #ifdef __CHAR_UNSIGNED__
3666 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3667 		sbi->s_hash_unsigned = 3;
3668 #else
3669 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3670 #endif
3671 	}
3672 
3673 	/* Handle clustersize */
3674 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3675 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3676 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3677 	if (has_bigalloc) {
3678 		if (clustersize < blocksize) {
3679 			ext4_msg(sb, KERN_ERR,
3680 				 "cluster size (%d) smaller than "
3681 				 "block size (%d)", clustersize, blocksize);
3682 			goto failed_mount;
3683 		}
3684 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3685 			le32_to_cpu(es->s_log_block_size);
3686 		sbi->s_clusters_per_group =
3687 			le32_to_cpu(es->s_clusters_per_group);
3688 		if (sbi->s_clusters_per_group > blocksize * 8) {
3689 			ext4_msg(sb, KERN_ERR,
3690 				 "#clusters per group too big: %lu",
3691 				 sbi->s_clusters_per_group);
3692 			goto failed_mount;
3693 		}
3694 		if (sbi->s_blocks_per_group !=
3695 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3696 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3697 				 "clusters per group (%lu) inconsistent",
3698 				 sbi->s_blocks_per_group,
3699 				 sbi->s_clusters_per_group);
3700 			goto failed_mount;
3701 		}
3702 	} else {
3703 		if (clustersize != blocksize) {
3704 			ext4_warning(sb, "fragment/cluster size (%d) != "
3705 				     "block size (%d)", clustersize,
3706 				     blocksize);
3707 			clustersize = blocksize;
3708 		}
3709 		if (sbi->s_blocks_per_group > blocksize * 8) {
3710 			ext4_msg(sb, KERN_ERR,
3711 				 "#blocks per group too big: %lu",
3712 				 sbi->s_blocks_per_group);
3713 			goto failed_mount;
3714 		}
3715 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3716 		sbi->s_cluster_bits = 0;
3717 	}
3718 	sbi->s_cluster_ratio = clustersize / blocksize;
3719 
3720 	if (sbi->s_inodes_per_group > blocksize * 8) {
3721 		ext4_msg(sb, KERN_ERR,
3722 		       "#inodes per group too big: %lu",
3723 		       sbi->s_inodes_per_group);
3724 		goto failed_mount;
3725 	}
3726 
3727 	/* Do we have standard group size of clustersize * 8 blocks ? */
3728 	if (sbi->s_blocks_per_group == clustersize << 3)
3729 		set_opt2(sb, STD_GROUP_SIZE);
3730 
3731 	/*
3732 	 * Test whether we have more sectors than will fit in sector_t,
3733 	 * and whether the max offset is addressable by the page cache.
3734 	 */
3735 	err = generic_check_addressable(sb->s_blocksize_bits,
3736 					ext4_blocks_count(es));
3737 	if (err) {
3738 		ext4_msg(sb, KERN_ERR, "filesystem"
3739 			 " too large to mount safely on this system");
3740 		if (sizeof(sector_t) < 8)
3741 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3742 		goto failed_mount;
3743 	}
3744 
3745 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3746 		goto cantfind_ext4;
3747 
3748 	/* check blocks count against device size */
3749 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3750 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3751 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3752 		       "exceeds size of device (%llu blocks)",
3753 		       ext4_blocks_count(es), blocks_count);
3754 		goto failed_mount;
3755 	}
3756 
3757 	/*
3758 	 * It makes no sense for the first data block to be beyond the end
3759 	 * of the filesystem.
3760 	 */
3761 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3762 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3763 			 "block %u is beyond end of filesystem (%llu)",
3764 			 le32_to_cpu(es->s_first_data_block),
3765 			 ext4_blocks_count(es));
3766 		goto failed_mount;
3767 	}
3768 	blocks_count = (ext4_blocks_count(es) -
3769 			le32_to_cpu(es->s_first_data_block) +
3770 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3771 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3772 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3773 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3774 		       "(block count %llu, first data block %u, "
3775 		       "blocks per group %lu)", sbi->s_groups_count,
3776 		       ext4_blocks_count(es),
3777 		       le32_to_cpu(es->s_first_data_block),
3778 		       EXT4_BLOCKS_PER_GROUP(sb));
3779 		goto failed_mount;
3780 	}
3781 	sbi->s_groups_count = blocks_count;
3782 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3783 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3784 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3785 		   EXT4_DESC_PER_BLOCK(sb);
3786 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3787 					  sizeof(struct buffer_head *),
3788 					  GFP_KERNEL);
3789 	if (sbi->s_group_desc == NULL) {
3790 		ext4_msg(sb, KERN_ERR, "not enough memory");
3791 		ret = -ENOMEM;
3792 		goto failed_mount;
3793 	}
3794 
3795 	if (ext4_proc_root)
3796 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3797 
3798 	if (sbi->s_proc)
3799 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3800 				 &ext4_seq_options_fops, sb);
3801 
3802 	bgl_lock_init(sbi->s_blockgroup_lock);
3803 
3804 	for (i = 0; i < db_count; i++) {
3805 		block = descriptor_loc(sb, logical_sb_block, i);
3806 		sbi->s_group_desc[i] = sb_bread(sb, block);
3807 		if (!sbi->s_group_desc[i]) {
3808 			ext4_msg(sb, KERN_ERR,
3809 			       "can't read group descriptor %d", i);
3810 			db_count = i;
3811 			goto failed_mount2;
3812 		}
3813 	}
3814 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3815 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3816 		goto failed_mount2;
3817 	}
3818 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3819 		if (!ext4_fill_flex_info(sb)) {
3820 			ext4_msg(sb, KERN_ERR,
3821 			       "unable to initialize "
3822 			       "flex_bg meta info!");
3823 			goto failed_mount2;
3824 		}
3825 
3826 	sbi->s_gdb_count = db_count;
3827 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3828 	spin_lock_init(&sbi->s_next_gen_lock);
3829 
3830 	init_timer(&sbi->s_err_report);
3831 	sbi->s_err_report.function = print_daily_error_info;
3832 	sbi->s_err_report.data = (unsigned long) sb;
3833 
3834 	/* Register extent status tree shrinker */
3835 	ext4_es_register_shrinker(sbi);
3836 
3837 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3838 			ext4_count_free_clusters(sb));
3839 	if (!err) {
3840 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3841 				ext4_count_free_inodes(sb));
3842 	}
3843 	if (!err) {
3844 		err = percpu_counter_init(&sbi->s_dirs_counter,
3845 				ext4_count_dirs(sb));
3846 	}
3847 	if (!err) {
3848 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3849 	}
3850 	if (!err) {
3851 		err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3852 	}
3853 	if (err) {
3854 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3855 		goto failed_mount3;
3856 	}
3857 
3858 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3859 	sbi->s_extent_max_zeroout_kb = 32;
3860 
3861 	/*
3862 	 * set up enough so that it can read an inode
3863 	 */
3864 	if (!test_opt(sb, NOLOAD) &&
3865 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3866 		sb->s_op = &ext4_sops;
3867 	else
3868 		sb->s_op = &ext4_nojournal_sops;
3869 	sb->s_export_op = &ext4_export_ops;
3870 	sb->s_xattr = ext4_xattr_handlers;
3871 #ifdef CONFIG_QUOTA
3872 	sb->dq_op = &ext4_quota_operations;
3873 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3874 		sb->s_qcop = &ext4_qctl_sysfile_operations;
3875 	else
3876 		sb->s_qcop = &ext4_qctl_operations;
3877 #endif
3878 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3879 
3880 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3881 	mutex_init(&sbi->s_orphan_lock);
3882 
3883 	sb->s_root = NULL;
3884 
3885 	needs_recovery = (es->s_last_orphan != 0 ||
3886 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3887 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3888 
3889 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3890 	    !(sb->s_flags & MS_RDONLY))
3891 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3892 			goto failed_mount3;
3893 
3894 	/*
3895 	 * The first inode we look at is the journal inode.  Don't try
3896 	 * root first: it may be modified in the journal!
3897 	 */
3898 	if (!test_opt(sb, NOLOAD) &&
3899 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3900 		if (ext4_load_journal(sb, es, journal_devnum))
3901 			goto failed_mount3;
3902 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3903 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3904 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3905 		       "suppressed and not mounted read-only");
3906 		goto failed_mount_wq;
3907 	} else {
3908 		clear_opt(sb, DATA_FLAGS);
3909 		sbi->s_journal = NULL;
3910 		needs_recovery = 0;
3911 		goto no_journal;
3912 	}
3913 
3914 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3915 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3916 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3917 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3918 		goto failed_mount_wq;
3919 	}
3920 
3921 	if (!set_journal_csum_feature_set(sb)) {
3922 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3923 			 "feature set");
3924 		goto failed_mount_wq;
3925 	}
3926 
3927 	/* We have now updated the journal if required, so we can
3928 	 * validate the data journaling mode. */
3929 	switch (test_opt(sb, DATA_FLAGS)) {
3930 	case 0:
3931 		/* No mode set, assume a default based on the journal
3932 		 * capabilities: ORDERED_DATA if the journal can
3933 		 * cope, else JOURNAL_DATA
3934 		 */
3935 		if (jbd2_journal_check_available_features
3936 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3937 			set_opt(sb, ORDERED_DATA);
3938 		else
3939 			set_opt(sb, JOURNAL_DATA);
3940 		break;
3941 
3942 	case EXT4_MOUNT_ORDERED_DATA:
3943 	case EXT4_MOUNT_WRITEBACK_DATA:
3944 		if (!jbd2_journal_check_available_features
3945 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3946 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3947 			       "requested data journaling mode");
3948 			goto failed_mount_wq;
3949 		}
3950 	default:
3951 		break;
3952 	}
3953 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3954 
3955 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3956 
3957 	/*
3958 	 * The journal may have updated the bg summary counts, so we
3959 	 * need to update the global counters.
3960 	 */
3961 	percpu_counter_set(&sbi->s_freeclusters_counter,
3962 			   ext4_count_free_clusters(sb));
3963 	percpu_counter_set(&sbi->s_freeinodes_counter,
3964 			   ext4_count_free_inodes(sb));
3965 	percpu_counter_set(&sbi->s_dirs_counter,
3966 			   ext4_count_dirs(sb));
3967 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3968 
3969 no_journal:
3970 	/*
3971 	 * Get the # of file system overhead blocks from the
3972 	 * superblock if present.
3973 	 */
3974 	if (es->s_overhead_clusters)
3975 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3976 	else {
3977 		err = ext4_calculate_overhead(sb);
3978 		if (err)
3979 			goto failed_mount_wq;
3980 	}
3981 
3982 	/*
3983 	 * The maximum number of concurrent works can be high and
3984 	 * concurrency isn't really necessary.  Limit it to 1.
3985 	 */
3986 	EXT4_SB(sb)->rsv_conversion_wq =
3987 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3988 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
3989 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3990 		ret = -ENOMEM;
3991 		goto failed_mount4;
3992 	}
3993 
3994 	/*
3995 	 * The jbd2_journal_load will have done any necessary log recovery,
3996 	 * so we can safely mount the rest of the filesystem now.
3997 	 */
3998 
3999 	root = ext4_iget(sb, EXT4_ROOT_INO);
4000 	if (IS_ERR(root)) {
4001 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4002 		ret = PTR_ERR(root);
4003 		root = NULL;
4004 		goto failed_mount4;
4005 	}
4006 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4007 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4008 		iput(root);
4009 		goto failed_mount4;
4010 	}
4011 	sb->s_root = d_make_root(root);
4012 	if (!sb->s_root) {
4013 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4014 		ret = -ENOMEM;
4015 		goto failed_mount4;
4016 	}
4017 
4018 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4019 		sb->s_flags |= MS_RDONLY;
4020 
4021 	/* determine the minimum size of new large inodes, if present */
4022 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4023 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4024 						     EXT4_GOOD_OLD_INODE_SIZE;
4025 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4026 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
4027 			if (sbi->s_want_extra_isize <
4028 			    le16_to_cpu(es->s_want_extra_isize))
4029 				sbi->s_want_extra_isize =
4030 					le16_to_cpu(es->s_want_extra_isize);
4031 			if (sbi->s_want_extra_isize <
4032 			    le16_to_cpu(es->s_min_extra_isize))
4033 				sbi->s_want_extra_isize =
4034 					le16_to_cpu(es->s_min_extra_isize);
4035 		}
4036 	}
4037 	/* Check if enough inode space is available */
4038 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4039 							sbi->s_inode_size) {
4040 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4041 						       EXT4_GOOD_OLD_INODE_SIZE;
4042 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4043 			 "available");
4044 	}
4045 
4046 	err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sbi));
4047 	if (err) {
4048 		ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4049 			 "reserved pool", ext4_calculate_resv_clusters(sbi));
4050 		goto failed_mount4a;
4051 	}
4052 
4053 	err = ext4_setup_system_zone(sb);
4054 	if (err) {
4055 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4056 			 "zone (%d)", err);
4057 		goto failed_mount4a;
4058 	}
4059 
4060 	ext4_ext_init(sb);
4061 	err = ext4_mb_init(sb);
4062 	if (err) {
4063 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4064 			 err);
4065 		goto failed_mount5;
4066 	}
4067 
4068 	err = ext4_register_li_request(sb, first_not_zeroed);
4069 	if (err)
4070 		goto failed_mount6;
4071 
4072 	sbi->s_kobj.kset = ext4_kset;
4073 	init_completion(&sbi->s_kobj_unregister);
4074 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4075 				   "%s", sb->s_id);
4076 	if (err)
4077 		goto failed_mount7;
4078 
4079 #ifdef CONFIG_QUOTA
4080 	/* Enable quota usage during mount. */
4081 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4082 	    !(sb->s_flags & MS_RDONLY)) {
4083 		err = ext4_enable_quotas(sb);
4084 		if (err)
4085 			goto failed_mount8;
4086 	}
4087 #endif  /* CONFIG_QUOTA */
4088 
4089 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4090 	ext4_orphan_cleanup(sb, es);
4091 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4092 	if (needs_recovery) {
4093 		ext4_msg(sb, KERN_INFO, "recovery complete");
4094 		ext4_mark_recovery_complete(sb, es);
4095 	}
4096 	if (EXT4_SB(sb)->s_journal) {
4097 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4098 			descr = " journalled data mode";
4099 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4100 			descr = " ordered data mode";
4101 		else
4102 			descr = " writeback data mode";
4103 	} else
4104 		descr = "out journal";
4105 
4106 	if (test_opt(sb, DISCARD)) {
4107 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4108 		if (!blk_queue_discard(q))
4109 			ext4_msg(sb, KERN_WARNING,
4110 				 "mounting with \"discard\" option, but "
4111 				 "the device does not support discard");
4112 	}
4113 
4114 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4115 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4116 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4117 
4118 	if (es->s_error_count)
4119 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4120 
4121 	kfree(orig_data);
4122 	return 0;
4123 
4124 cantfind_ext4:
4125 	if (!silent)
4126 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4127 	goto failed_mount;
4128 
4129 #ifdef CONFIG_QUOTA
4130 failed_mount8:
4131 	kobject_del(&sbi->s_kobj);
4132 #endif
4133 failed_mount7:
4134 	ext4_unregister_li_request(sb);
4135 failed_mount6:
4136 	ext4_mb_release(sb);
4137 failed_mount5:
4138 	ext4_ext_release(sb);
4139 	ext4_release_system_zone(sb);
4140 failed_mount4a:
4141 	dput(sb->s_root);
4142 	sb->s_root = NULL;
4143 failed_mount4:
4144 	ext4_msg(sb, KERN_ERR, "mount failed");
4145 	if (EXT4_SB(sb)->rsv_conversion_wq)
4146 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4147 failed_mount_wq:
4148 	if (sbi->s_journal) {
4149 		jbd2_journal_destroy(sbi->s_journal);
4150 		sbi->s_journal = NULL;
4151 	}
4152 failed_mount3:
4153 	ext4_es_unregister_shrinker(sbi);
4154 	del_timer(&sbi->s_err_report);
4155 	if (sbi->s_flex_groups)
4156 		ext4_kvfree(sbi->s_flex_groups);
4157 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4158 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4159 	percpu_counter_destroy(&sbi->s_dirs_counter);
4160 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4161 	percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4162 	if (sbi->s_mmp_tsk)
4163 		kthread_stop(sbi->s_mmp_tsk);
4164 failed_mount2:
4165 	for (i = 0; i < db_count; i++)
4166 		brelse(sbi->s_group_desc[i]);
4167 	ext4_kvfree(sbi->s_group_desc);
4168 failed_mount:
4169 	if (sbi->s_chksum_driver)
4170 		crypto_free_shash(sbi->s_chksum_driver);
4171 	if (sbi->s_proc) {
4172 		remove_proc_entry("options", sbi->s_proc);
4173 		remove_proc_entry(sb->s_id, ext4_proc_root);
4174 	}
4175 #ifdef CONFIG_QUOTA
4176 	for (i = 0; i < MAXQUOTAS; i++)
4177 		kfree(sbi->s_qf_names[i]);
4178 #endif
4179 	ext4_blkdev_remove(sbi);
4180 	brelse(bh);
4181 out_fail:
4182 	sb->s_fs_info = NULL;
4183 	kfree(sbi->s_blockgroup_lock);
4184 	kfree(sbi);
4185 out_free_orig:
4186 	kfree(orig_data);
4187 	return err ? err : ret;
4188 }
4189 
4190 /*
4191  * Setup any per-fs journal parameters now.  We'll do this both on
4192  * initial mount, once the journal has been initialised but before we've
4193  * done any recovery; and again on any subsequent remount.
4194  */
4195 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4196 {
4197 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4198 
4199 	journal->j_commit_interval = sbi->s_commit_interval;
4200 	journal->j_min_batch_time = sbi->s_min_batch_time;
4201 	journal->j_max_batch_time = sbi->s_max_batch_time;
4202 
4203 	write_lock(&journal->j_state_lock);
4204 	if (test_opt(sb, BARRIER))
4205 		journal->j_flags |= JBD2_BARRIER;
4206 	else
4207 		journal->j_flags &= ~JBD2_BARRIER;
4208 	if (test_opt(sb, DATA_ERR_ABORT))
4209 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4210 	else
4211 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4212 	write_unlock(&journal->j_state_lock);
4213 }
4214 
4215 static journal_t *ext4_get_journal(struct super_block *sb,
4216 				   unsigned int journal_inum)
4217 {
4218 	struct inode *journal_inode;
4219 	journal_t *journal;
4220 
4221 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4222 
4223 	/* First, test for the existence of a valid inode on disk.  Bad
4224 	 * things happen if we iget() an unused inode, as the subsequent
4225 	 * iput() will try to delete it. */
4226 
4227 	journal_inode = ext4_iget(sb, journal_inum);
4228 	if (IS_ERR(journal_inode)) {
4229 		ext4_msg(sb, KERN_ERR, "no journal found");
4230 		return NULL;
4231 	}
4232 	if (!journal_inode->i_nlink) {
4233 		make_bad_inode(journal_inode);
4234 		iput(journal_inode);
4235 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4236 		return NULL;
4237 	}
4238 
4239 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4240 		  journal_inode, journal_inode->i_size);
4241 	if (!S_ISREG(journal_inode->i_mode)) {
4242 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4243 		iput(journal_inode);
4244 		return NULL;
4245 	}
4246 
4247 	journal = jbd2_journal_init_inode(journal_inode);
4248 	if (!journal) {
4249 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4250 		iput(journal_inode);
4251 		return NULL;
4252 	}
4253 	journal->j_private = sb;
4254 	ext4_init_journal_params(sb, journal);
4255 	return journal;
4256 }
4257 
4258 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4259 				       dev_t j_dev)
4260 {
4261 	struct buffer_head *bh;
4262 	journal_t *journal;
4263 	ext4_fsblk_t start;
4264 	ext4_fsblk_t len;
4265 	int hblock, blocksize;
4266 	ext4_fsblk_t sb_block;
4267 	unsigned long offset;
4268 	struct ext4_super_block *es;
4269 	struct block_device *bdev;
4270 
4271 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4272 
4273 	bdev = ext4_blkdev_get(j_dev, sb);
4274 	if (bdev == NULL)
4275 		return NULL;
4276 
4277 	blocksize = sb->s_blocksize;
4278 	hblock = bdev_logical_block_size(bdev);
4279 	if (blocksize < hblock) {
4280 		ext4_msg(sb, KERN_ERR,
4281 			"blocksize too small for journal device");
4282 		goto out_bdev;
4283 	}
4284 
4285 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4286 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4287 	set_blocksize(bdev, blocksize);
4288 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4289 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4290 		       "external journal");
4291 		goto out_bdev;
4292 	}
4293 
4294 	es = (struct ext4_super_block *) (bh->b_data + offset);
4295 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4296 	    !(le32_to_cpu(es->s_feature_incompat) &
4297 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4298 		ext4_msg(sb, KERN_ERR, "external journal has "
4299 					"bad superblock");
4300 		brelse(bh);
4301 		goto out_bdev;
4302 	}
4303 
4304 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4305 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4306 		brelse(bh);
4307 		goto out_bdev;
4308 	}
4309 
4310 	len = ext4_blocks_count(es);
4311 	start = sb_block + 1;
4312 	brelse(bh);	/* we're done with the superblock */
4313 
4314 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4315 					start, len, blocksize);
4316 	if (!journal) {
4317 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4318 		goto out_bdev;
4319 	}
4320 	journal->j_private = sb;
4321 	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4322 	wait_on_buffer(journal->j_sb_buffer);
4323 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4324 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4325 		goto out_journal;
4326 	}
4327 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4328 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4329 					"user (unsupported) - %d",
4330 			be32_to_cpu(journal->j_superblock->s_nr_users));
4331 		goto out_journal;
4332 	}
4333 	EXT4_SB(sb)->journal_bdev = bdev;
4334 	ext4_init_journal_params(sb, journal);
4335 	return journal;
4336 
4337 out_journal:
4338 	jbd2_journal_destroy(journal);
4339 out_bdev:
4340 	ext4_blkdev_put(bdev);
4341 	return NULL;
4342 }
4343 
4344 static int ext4_load_journal(struct super_block *sb,
4345 			     struct ext4_super_block *es,
4346 			     unsigned long journal_devnum)
4347 {
4348 	journal_t *journal;
4349 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4350 	dev_t journal_dev;
4351 	int err = 0;
4352 	int really_read_only;
4353 
4354 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4355 
4356 	if (journal_devnum &&
4357 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4358 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4359 			"numbers have changed");
4360 		journal_dev = new_decode_dev(journal_devnum);
4361 	} else
4362 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4363 
4364 	really_read_only = bdev_read_only(sb->s_bdev);
4365 
4366 	/*
4367 	 * Are we loading a blank journal or performing recovery after a
4368 	 * crash?  For recovery, we need to check in advance whether we
4369 	 * can get read-write access to the device.
4370 	 */
4371 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4372 		if (sb->s_flags & MS_RDONLY) {
4373 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4374 					"required on readonly filesystem");
4375 			if (really_read_only) {
4376 				ext4_msg(sb, KERN_ERR, "write access "
4377 					"unavailable, cannot proceed");
4378 				return -EROFS;
4379 			}
4380 			ext4_msg(sb, KERN_INFO, "write access will "
4381 			       "be enabled during recovery");
4382 		}
4383 	}
4384 
4385 	if (journal_inum && journal_dev) {
4386 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4387 		       "and inode journals!");
4388 		return -EINVAL;
4389 	}
4390 
4391 	if (journal_inum) {
4392 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4393 			return -EINVAL;
4394 	} else {
4395 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4396 			return -EINVAL;
4397 	}
4398 
4399 	if (!(journal->j_flags & JBD2_BARRIER))
4400 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4401 
4402 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4403 		err = jbd2_journal_wipe(journal, !really_read_only);
4404 	if (!err) {
4405 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4406 		if (save)
4407 			memcpy(save, ((char *) es) +
4408 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4409 		err = jbd2_journal_load(journal);
4410 		if (save)
4411 			memcpy(((char *) es) + EXT4_S_ERR_START,
4412 			       save, EXT4_S_ERR_LEN);
4413 		kfree(save);
4414 	}
4415 
4416 	if (err) {
4417 		ext4_msg(sb, KERN_ERR, "error loading journal");
4418 		jbd2_journal_destroy(journal);
4419 		return err;
4420 	}
4421 
4422 	EXT4_SB(sb)->s_journal = journal;
4423 	ext4_clear_journal_err(sb, es);
4424 
4425 	if (!really_read_only && journal_devnum &&
4426 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4427 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4428 
4429 		/* Make sure we flush the recovery flag to disk. */
4430 		ext4_commit_super(sb, 1);
4431 	}
4432 
4433 	return 0;
4434 }
4435 
4436 static int ext4_commit_super(struct super_block *sb, int sync)
4437 {
4438 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4439 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4440 	int error = 0;
4441 
4442 	if (!sbh || block_device_ejected(sb))
4443 		return error;
4444 	if (buffer_write_io_error(sbh)) {
4445 		/*
4446 		 * Oh, dear.  A previous attempt to write the
4447 		 * superblock failed.  This could happen because the
4448 		 * USB device was yanked out.  Or it could happen to
4449 		 * be a transient write error and maybe the block will
4450 		 * be remapped.  Nothing we can do but to retry the
4451 		 * write and hope for the best.
4452 		 */
4453 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4454 		       "superblock detected");
4455 		clear_buffer_write_io_error(sbh);
4456 		set_buffer_uptodate(sbh);
4457 	}
4458 	/*
4459 	 * If the file system is mounted read-only, don't update the
4460 	 * superblock write time.  This avoids updating the superblock
4461 	 * write time when we are mounting the root file system
4462 	 * read/only but we need to replay the journal; at that point,
4463 	 * for people who are east of GMT and who make their clock
4464 	 * tick in localtime for Windows bug-for-bug compatibility,
4465 	 * the clock is set in the future, and this will cause e2fsck
4466 	 * to complain and force a full file system check.
4467 	 */
4468 	if (!(sb->s_flags & MS_RDONLY))
4469 		es->s_wtime = cpu_to_le32(get_seconds());
4470 	if (sb->s_bdev->bd_part)
4471 		es->s_kbytes_written =
4472 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4473 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4474 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4475 	else
4476 		es->s_kbytes_written =
4477 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4478 	ext4_free_blocks_count_set(es,
4479 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4480 				&EXT4_SB(sb)->s_freeclusters_counter)));
4481 	es->s_free_inodes_count =
4482 		cpu_to_le32(percpu_counter_sum_positive(
4483 				&EXT4_SB(sb)->s_freeinodes_counter));
4484 	BUFFER_TRACE(sbh, "marking dirty");
4485 	ext4_superblock_csum_set(sb);
4486 	mark_buffer_dirty(sbh);
4487 	if (sync) {
4488 		error = sync_dirty_buffer(sbh);
4489 		if (error)
4490 			return error;
4491 
4492 		error = buffer_write_io_error(sbh);
4493 		if (error) {
4494 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4495 			       "superblock");
4496 			clear_buffer_write_io_error(sbh);
4497 			set_buffer_uptodate(sbh);
4498 		}
4499 	}
4500 	return error;
4501 }
4502 
4503 /*
4504  * Have we just finished recovery?  If so, and if we are mounting (or
4505  * remounting) the filesystem readonly, then we will end up with a
4506  * consistent fs on disk.  Record that fact.
4507  */
4508 static void ext4_mark_recovery_complete(struct super_block *sb,
4509 					struct ext4_super_block *es)
4510 {
4511 	journal_t *journal = EXT4_SB(sb)->s_journal;
4512 
4513 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4514 		BUG_ON(journal != NULL);
4515 		return;
4516 	}
4517 	jbd2_journal_lock_updates(journal);
4518 	if (jbd2_journal_flush(journal) < 0)
4519 		goto out;
4520 
4521 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4522 	    sb->s_flags & MS_RDONLY) {
4523 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4524 		ext4_commit_super(sb, 1);
4525 	}
4526 
4527 out:
4528 	jbd2_journal_unlock_updates(journal);
4529 }
4530 
4531 /*
4532  * If we are mounting (or read-write remounting) a filesystem whose journal
4533  * has recorded an error from a previous lifetime, move that error to the
4534  * main filesystem now.
4535  */
4536 static void ext4_clear_journal_err(struct super_block *sb,
4537 				   struct ext4_super_block *es)
4538 {
4539 	journal_t *journal;
4540 	int j_errno;
4541 	const char *errstr;
4542 
4543 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4544 
4545 	journal = EXT4_SB(sb)->s_journal;
4546 
4547 	/*
4548 	 * Now check for any error status which may have been recorded in the
4549 	 * journal by a prior ext4_error() or ext4_abort()
4550 	 */
4551 
4552 	j_errno = jbd2_journal_errno(journal);
4553 	if (j_errno) {
4554 		char nbuf[16];
4555 
4556 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4557 		ext4_warning(sb, "Filesystem error recorded "
4558 			     "from previous mount: %s", errstr);
4559 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4560 
4561 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4562 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4563 		ext4_commit_super(sb, 1);
4564 
4565 		jbd2_journal_clear_err(journal);
4566 		jbd2_journal_update_sb_errno(journal);
4567 	}
4568 }
4569 
4570 /*
4571  * Force the running and committing transactions to commit,
4572  * and wait on the commit.
4573  */
4574 int ext4_force_commit(struct super_block *sb)
4575 {
4576 	journal_t *journal;
4577 
4578 	if (sb->s_flags & MS_RDONLY)
4579 		return 0;
4580 
4581 	journal = EXT4_SB(sb)->s_journal;
4582 	return ext4_journal_force_commit(journal);
4583 }
4584 
4585 static int ext4_sync_fs(struct super_block *sb, int wait)
4586 {
4587 	int ret = 0;
4588 	tid_t target;
4589 	bool needs_barrier = false;
4590 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4591 
4592 	trace_ext4_sync_fs(sb, wait);
4593 	flush_workqueue(sbi->rsv_conversion_wq);
4594 	/*
4595 	 * Writeback quota in non-journalled quota case - journalled quota has
4596 	 * no dirty dquots
4597 	 */
4598 	dquot_writeback_dquots(sb, -1);
4599 	/*
4600 	 * Data writeback is possible w/o journal transaction, so barrier must
4601 	 * being sent at the end of the function. But we can skip it if
4602 	 * transaction_commit will do it for us.
4603 	 */
4604 	target = jbd2_get_latest_transaction(sbi->s_journal);
4605 	if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4606 	    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4607 		needs_barrier = true;
4608 
4609 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4610 		if (wait)
4611 			ret = jbd2_log_wait_commit(sbi->s_journal, target);
4612 	}
4613 	if (needs_barrier) {
4614 		int err;
4615 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4616 		if (!ret)
4617 			ret = err;
4618 	}
4619 
4620 	return ret;
4621 }
4622 
4623 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4624 {
4625 	int ret = 0;
4626 
4627 	trace_ext4_sync_fs(sb, wait);
4628 	flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4629 	dquot_writeback_dquots(sb, -1);
4630 	if (wait && test_opt(sb, BARRIER))
4631 		ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4632 
4633 	return ret;
4634 }
4635 
4636 /*
4637  * LVM calls this function before a (read-only) snapshot is created.  This
4638  * gives us a chance to flush the journal completely and mark the fs clean.
4639  *
4640  * Note that only this function cannot bring a filesystem to be in a clean
4641  * state independently. It relies on upper layer to stop all data & metadata
4642  * modifications.
4643  */
4644 static int ext4_freeze(struct super_block *sb)
4645 {
4646 	int error = 0;
4647 	journal_t *journal;
4648 
4649 	if (sb->s_flags & MS_RDONLY)
4650 		return 0;
4651 
4652 	journal = EXT4_SB(sb)->s_journal;
4653 
4654 	/* Now we set up the journal barrier. */
4655 	jbd2_journal_lock_updates(journal);
4656 
4657 	/*
4658 	 * Don't clear the needs_recovery flag if we failed to flush
4659 	 * the journal.
4660 	 */
4661 	error = jbd2_journal_flush(journal);
4662 	if (error < 0)
4663 		goto out;
4664 
4665 	/* Journal blocked and flushed, clear needs_recovery flag. */
4666 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4667 	error = ext4_commit_super(sb, 1);
4668 out:
4669 	/* we rely on upper layer to stop further updates */
4670 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4671 	return error;
4672 }
4673 
4674 /*
4675  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4676  * flag here, even though the filesystem is not technically dirty yet.
4677  */
4678 static int ext4_unfreeze(struct super_block *sb)
4679 {
4680 	if (sb->s_flags & MS_RDONLY)
4681 		return 0;
4682 
4683 	/* Reset the needs_recovery flag before the fs is unlocked. */
4684 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4685 	ext4_commit_super(sb, 1);
4686 	return 0;
4687 }
4688 
4689 /*
4690  * Structure to save mount options for ext4_remount's benefit
4691  */
4692 struct ext4_mount_options {
4693 	unsigned long s_mount_opt;
4694 	unsigned long s_mount_opt2;
4695 	kuid_t s_resuid;
4696 	kgid_t s_resgid;
4697 	unsigned long s_commit_interval;
4698 	u32 s_min_batch_time, s_max_batch_time;
4699 #ifdef CONFIG_QUOTA
4700 	int s_jquota_fmt;
4701 	char *s_qf_names[MAXQUOTAS];
4702 #endif
4703 };
4704 
4705 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4706 {
4707 	struct ext4_super_block *es;
4708 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4709 	unsigned long old_sb_flags;
4710 	struct ext4_mount_options old_opts;
4711 	int enable_quota = 0;
4712 	ext4_group_t g;
4713 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4714 	int err = 0;
4715 #ifdef CONFIG_QUOTA
4716 	int i, j;
4717 #endif
4718 	char *orig_data = kstrdup(data, GFP_KERNEL);
4719 
4720 	/* Store the original options */
4721 	old_sb_flags = sb->s_flags;
4722 	old_opts.s_mount_opt = sbi->s_mount_opt;
4723 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4724 	old_opts.s_resuid = sbi->s_resuid;
4725 	old_opts.s_resgid = sbi->s_resgid;
4726 	old_opts.s_commit_interval = sbi->s_commit_interval;
4727 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4728 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4729 #ifdef CONFIG_QUOTA
4730 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4731 	for (i = 0; i < MAXQUOTAS; i++)
4732 		if (sbi->s_qf_names[i]) {
4733 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4734 							 GFP_KERNEL);
4735 			if (!old_opts.s_qf_names[i]) {
4736 				for (j = 0; j < i; j++)
4737 					kfree(old_opts.s_qf_names[j]);
4738 				kfree(orig_data);
4739 				return -ENOMEM;
4740 			}
4741 		} else
4742 			old_opts.s_qf_names[i] = NULL;
4743 #endif
4744 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4745 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4746 
4747 	/*
4748 	 * Allow the "check" option to be passed as a remount option.
4749 	 */
4750 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4751 		err = -EINVAL;
4752 		goto restore_opts;
4753 	}
4754 
4755 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4756 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4757 			ext4_msg(sb, KERN_ERR, "can't mount with "
4758 				 "both data=journal and delalloc");
4759 			err = -EINVAL;
4760 			goto restore_opts;
4761 		}
4762 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4763 			ext4_msg(sb, KERN_ERR, "can't mount with "
4764 				 "both data=journal and dioread_nolock");
4765 			err = -EINVAL;
4766 			goto restore_opts;
4767 		}
4768 	}
4769 
4770 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4771 		ext4_abort(sb, "Abort forced by user");
4772 
4773 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4774 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4775 
4776 	es = sbi->s_es;
4777 
4778 	if (sbi->s_journal) {
4779 		ext4_init_journal_params(sb, sbi->s_journal);
4780 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4781 	}
4782 
4783 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4784 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4785 			err = -EROFS;
4786 			goto restore_opts;
4787 		}
4788 
4789 		if (*flags & MS_RDONLY) {
4790 			err = dquot_suspend(sb, -1);
4791 			if (err < 0)
4792 				goto restore_opts;
4793 
4794 			/*
4795 			 * First of all, the unconditional stuff we have to do
4796 			 * to disable replay of the journal when we next remount
4797 			 */
4798 			sb->s_flags |= MS_RDONLY;
4799 
4800 			/*
4801 			 * OK, test if we are remounting a valid rw partition
4802 			 * readonly, and if so set the rdonly flag and then
4803 			 * mark the partition as valid again.
4804 			 */
4805 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4806 			    (sbi->s_mount_state & EXT4_VALID_FS))
4807 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4808 
4809 			if (sbi->s_journal)
4810 				ext4_mark_recovery_complete(sb, es);
4811 		} else {
4812 			/* Make sure we can mount this feature set readwrite */
4813 			if (!ext4_feature_set_ok(sb, 0)) {
4814 				err = -EROFS;
4815 				goto restore_opts;
4816 			}
4817 			/*
4818 			 * Make sure the group descriptor checksums
4819 			 * are sane.  If they aren't, refuse to remount r/w.
4820 			 */
4821 			for (g = 0; g < sbi->s_groups_count; g++) {
4822 				struct ext4_group_desc *gdp =
4823 					ext4_get_group_desc(sb, g, NULL);
4824 
4825 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4826 					ext4_msg(sb, KERN_ERR,
4827 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4828 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4829 					       le16_to_cpu(gdp->bg_checksum));
4830 					err = -EINVAL;
4831 					goto restore_opts;
4832 				}
4833 			}
4834 
4835 			/*
4836 			 * If we have an unprocessed orphan list hanging
4837 			 * around from a previously readonly bdev mount,
4838 			 * require a full umount/remount for now.
4839 			 */
4840 			if (es->s_last_orphan) {
4841 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4842 				       "remount RDWR because of unprocessed "
4843 				       "orphan inode list.  Please "
4844 				       "umount/remount instead");
4845 				err = -EINVAL;
4846 				goto restore_opts;
4847 			}
4848 
4849 			/*
4850 			 * Mounting a RDONLY partition read-write, so reread
4851 			 * and store the current valid flag.  (It may have
4852 			 * been changed by e2fsck since we originally mounted
4853 			 * the partition.)
4854 			 */
4855 			if (sbi->s_journal)
4856 				ext4_clear_journal_err(sb, es);
4857 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4858 			if (!ext4_setup_super(sb, es, 0))
4859 				sb->s_flags &= ~MS_RDONLY;
4860 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4861 						     EXT4_FEATURE_INCOMPAT_MMP))
4862 				if (ext4_multi_mount_protect(sb,
4863 						le64_to_cpu(es->s_mmp_block))) {
4864 					err = -EROFS;
4865 					goto restore_opts;
4866 				}
4867 			enable_quota = 1;
4868 		}
4869 	}
4870 
4871 	/*
4872 	 * Reinitialize lazy itable initialization thread based on
4873 	 * current settings
4874 	 */
4875 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4876 		ext4_unregister_li_request(sb);
4877 	else {
4878 		ext4_group_t first_not_zeroed;
4879 		first_not_zeroed = ext4_has_uninit_itable(sb);
4880 		ext4_register_li_request(sb, first_not_zeroed);
4881 	}
4882 
4883 	ext4_setup_system_zone(sb);
4884 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4885 		ext4_commit_super(sb, 1);
4886 
4887 #ifdef CONFIG_QUOTA
4888 	/* Release old quota file names */
4889 	for (i = 0; i < MAXQUOTAS; i++)
4890 		kfree(old_opts.s_qf_names[i]);
4891 	if (enable_quota) {
4892 		if (sb_any_quota_suspended(sb))
4893 			dquot_resume(sb, -1);
4894 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4895 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4896 			err = ext4_enable_quotas(sb);
4897 			if (err)
4898 				goto restore_opts;
4899 		}
4900 	}
4901 #endif
4902 
4903 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4904 	kfree(orig_data);
4905 	return 0;
4906 
4907 restore_opts:
4908 	sb->s_flags = old_sb_flags;
4909 	sbi->s_mount_opt = old_opts.s_mount_opt;
4910 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4911 	sbi->s_resuid = old_opts.s_resuid;
4912 	sbi->s_resgid = old_opts.s_resgid;
4913 	sbi->s_commit_interval = old_opts.s_commit_interval;
4914 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4915 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4916 #ifdef CONFIG_QUOTA
4917 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4918 	for (i = 0; i < MAXQUOTAS; i++) {
4919 		kfree(sbi->s_qf_names[i]);
4920 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4921 	}
4922 #endif
4923 	kfree(orig_data);
4924 	return err;
4925 }
4926 
4927 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4928 {
4929 	struct super_block *sb = dentry->d_sb;
4930 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4931 	struct ext4_super_block *es = sbi->s_es;
4932 	ext4_fsblk_t overhead = 0, resv_blocks;
4933 	u64 fsid;
4934 	s64 bfree;
4935 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4936 
4937 	if (!test_opt(sb, MINIX_DF))
4938 		overhead = sbi->s_overhead;
4939 
4940 	buf->f_type = EXT4_SUPER_MAGIC;
4941 	buf->f_bsize = sb->s_blocksize;
4942 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4943 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4944 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4945 	/* prevent underflow in case that few free space is available */
4946 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4947 	buf->f_bavail = buf->f_bfree -
4948 			(ext4_r_blocks_count(es) + resv_blocks);
4949 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4950 		buf->f_bavail = 0;
4951 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4952 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4953 	buf->f_namelen = EXT4_NAME_LEN;
4954 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4955 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4956 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4957 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4958 
4959 	return 0;
4960 }
4961 
4962 /* Helper function for writing quotas on sync - we need to start transaction
4963  * before quota file is locked for write. Otherwise the are possible deadlocks:
4964  * Process 1                         Process 2
4965  * ext4_create()                     quota_sync()
4966  *   jbd2_journal_start()                  write_dquot()
4967  *   dquot_initialize()                         down(dqio_mutex)
4968  *     down(dqio_mutex)                    jbd2_journal_start()
4969  *
4970  */
4971 
4972 #ifdef CONFIG_QUOTA
4973 
4974 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4975 {
4976 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4977 }
4978 
4979 static int ext4_write_dquot(struct dquot *dquot)
4980 {
4981 	int ret, err;
4982 	handle_t *handle;
4983 	struct inode *inode;
4984 
4985 	inode = dquot_to_inode(dquot);
4986 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4987 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4988 	if (IS_ERR(handle))
4989 		return PTR_ERR(handle);
4990 	ret = dquot_commit(dquot);
4991 	err = ext4_journal_stop(handle);
4992 	if (!ret)
4993 		ret = err;
4994 	return ret;
4995 }
4996 
4997 static int ext4_acquire_dquot(struct dquot *dquot)
4998 {
4999 	int ret, err;
5000 	handle_t *handle;
5001 
5002 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5003 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5004 	if (IS_ERR(handle))
5005 		return PTR_ERR(handle);
5006 	ret = dquot_acquire(dquot);
5007 	err = ext4_journal_stop(handle);
5008 	if (!ret)
5009 		ret = err;
5010 	return ret;
5011 }
5012 
5013 static int ext4_release_dquot(struct dquot *dquot)
5014 {
5015 	int ret, err;
5016 	handle_t *handle;
5017 
5018 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5019 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5020 	if (IS_ERR(handle)) {
5021 		/* Release dquot anyway to avoid endless cycle in dqput() */
5022 		dquot_release(dquot);
5023 		return PTR_ERR(handle);
5024 	}
5025 	ret = dquot_release(dquot);
5026 	err = ext4_journal_stop(handle);
5027 	if (!ret)
5028 		ret = err;
5029 	return ret;
5030 }
5031 
5032 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5033 {
5034 	struct super_block *sb = dquot->dq_sb;
5035 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5036 
5037 	/* Are we journaling quotas? */
5038 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5039 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5040 		dquot_mark_dquot_dirty(dquot);
5041 		return ext4_write_dquot(dquot);
5042 	} else {
5043 		return dquot_mark_dquot_dirty(dquot);
5044 	}
5045 }
5046 
5047 static int ext4_write_info(struct super_block *sb, int type)
5048 {
5049 	int ret, err;
5050 	handle_t *handle;
5051 
5052 	/* Data block + inode block */
5053 	handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5054 	if (IS_ERR(handle))
5055 		return PTR_ERR(handle);
5056 	ret = dquot_commit_info(sb, type);
5057 	err = ext4_journal_stop(handle);
5058 	if (!ret)
5059 		ret = err;
5060 	return ret;
5061 }
5062 
5063 /*
5064  * Turn on quotas during mount time - we need to find
5065  * the quota file and such...
5066  */
5067 static int ext4_quota_on_mount(struct super_block *sb, int type)
5068 {
5069 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5070 					EXT4_SB(sb)->s_jquota_fmt, type);
5071 }
5072 
5073 /*
5074  * Standard function to be called on quota_on
5075  */
5076 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5077 			 struct path *path)
5078 {
5079 	int err;
5080 
5081 	if (!test_opt(sb, QUOTA))
5082 		return -EINVAL;
5083 
5084 	/* Quotafile not on the same filesystem? */
5085 	if (path->dentry->d_sb != sb)
5086 		return -EXDEV;
5087 	/* Journaling quota? */
5088 	if (EXT4_SB(sb)->s_qf_names[type]) {
5089 		/* Quotafile not in fs root? */
5090 		if (path->dentry->d_parent != sb->s_root)
5091 			ext4_msg(sb, KERN_WARNING,
5092 				"Quota file not on filesystem root. "
5093 				"Journaled quota will not work");
5094 	}
5095 
5096 	/*
5097 	 * When we journal data on quota file, we have to flush journal to see
5098 	 * all updates to the file when we bypass pagecache...
5099 	 */
5100 	if (EXT4_SB(sb)->s_journal &&
5101 	    ext4_should_journal_data(path->dentry->d_inode)) {
5102 		/*
5103 		 * We don't need to lock updates but journal_flush() could
5104 		 * otherwise be livelocked...
5105 		 */
5106 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5107 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5108 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5109 		if (err)
5110 			return err;
5111 	}
5112 
5113 	return dquot_quota_on(sb, type, format_id, path);
5114 }
5115 
5116 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5117 			     unsigned int flags)
5118 {
5119 	int err;
5120 	struct inode *qf_inode;
5121 	unsigned long qf_inums[MAXQUOTAS] = {
5122 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5123 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5124 	};
5125 
5126 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5127 
5128 	if (!qf_inums[type])
5129 		return -EPERM;
5130 
5131 	qf_inode = ext4_iget(sb, qf_inums[type]);
5132 	if (IS_ERR(qf_inode)) {
5133 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5134 		return PTR_ERR(qf_inode);
5135 	}
5136 
5137 	/* Don't account quota for quota files to avoid recursion */
5138 	qf_inode->i_flags |= S_NOQUOTA;
5139 	err = dquot_enable(qf_inode, type, format_id, flags);
5140 	iput(qf_inode);
5141 
5142 	return err;
5143 }
5144 
5145 /* Enable usage tracking for all quota types. */
5146 static int ext4_enable_quotas(struct super_block *sb)
5147 {
5148 	int type, err = 0;
5149 	unsigned long qf_inums[MAXQUOTAS] = {
5150 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5151 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5152 	};
5153 
5154 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5155 	for (type = 0; type < MAXQUOTAS; type++) {
5156 		if (qf_inums[type]) {
5157 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5158 						DQUOT_USAGE_ENABLED);
5159 			if (err) {
5160 				ext4_warning(sb,
5161 					"Failed to enable quota tracking "
5162 					"(type=%d, err=%d). Please run "
5163 					"e2fsck to fix.", type, err);
5164 				return err;
5165 			}
5166 		}
5167 	}
5168 	return 0;
5169 }
5170 
5171 /*
5172  * quota_on function that is used when QUOTA feature is set.
5173  */
5174 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5175 				 int format_id)
5176 {
5177 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5178 		return -EINVAL;
5179 
5180 	/*
5181 	 * USAGE was enabled at mount time. Only need to enable LIMITS now.
5182 	 */
5183 	return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5184 }
5185 
5186 static int ext4_quota_off(struct super_block *sb, int type)
5187 {
5188 	struct inode *inode = sb_dqopt(sb)->files[type];
5189 	handle_t *handle;
5190 
5191 	/* Force all delayed allocation blocks to be allocated.
5192 	 * Caller already holds s_umount sem */
5193 	if (test_opt(sb, DELALLOC))
5194 		sync_filesystem(sb);
5195 
5196 	if (!inode)
5197 		goto out;
5198 
5199 	/* Update modification times of quota files when userspace can
5200 	 * start looking at them */
5201 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5202 	if (IS_ERR(handle))
5203 		goto out;
5204 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5205 	ext4_mark_inode_dirty(handle, inode);
5206 	ext4_journal_stop(handle);
5207 
5208 out:
5209 	return dquot_quota_off(sb, type);
5210 }
5211 
5212 /*
5213  * quota_off function that is used when QUOTA feature is set.
5214  */
5215 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5216 {
5217 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5218 		return -EINVAL;
5219 
5220 	/* Disable only the limits. */
5221 	return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5222 }
5223 
5224 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5225  * acquiring the locks... As quota files are never truncated and quota code
5226  * itself serializes the operations (and no one else should touch the files)
5227  * we don't have to be afraid of races */
5228 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5229 			       size_t len, loff_t off)
5230 {
5231 	struct inode *inode = sb_dqopt(sb)->files[type];
5232 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5233 	int err = 0;
5234 	int offset = off & (sb->s_blocksize - 1);
5235 	int tocopy;
5236 	size_t toread;
5237 	struct buffer_head *bh;
5238 	loff_t i_size = i_size_read(inode);
5239 
5240 	if (off > i_size)
5241 		return 0;
5242 	if (off+len > i_size)
5243 		len = i_size-off;
5244 	toread = len;
5245 	while (toread > 0) {
5246 		tocopy = sb->s_blocksize - offset < toread ?
5247 				sb->s_blocksize - offset : toread;
5248 		bh = ext4_bread(NULL, inode, blk, 0, &err);
5249 		if (err)
5250 			return err;
5251 		if (!bh)	/* A hole? */
5252 			memset(data, 0, tocopy);
5253 		else
5254 			memcpy(data, bh->b_data+offset, tocopy);
5255 		brelse(bh);
5256 		offset = 0;
5257 		toread -= tocopy;
5258 		data += tocopy;
5259 		blk++;
5260 	}
5261 	return len;
5262 }
5263 
5264 /* Write to quotafile (we know the transaction is already started and has
5265  * enough credits) */
5266 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5267 				const char *data, size_t len, loff_t off)
5268 {
5269 	struct inode *inode = sb_dqopt(sb)->files[type];
5270 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5271 	int err = 0;
5272 	int offset = off & (sb->s_blocksize - 1);
5273 	struct buffer_head *bh;
5274 	handle_t *handle = journal_current_handle();
5275 
5276 	if (EXT4_SB(sb)->s_journal && !handle) {
5277 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5278 			" cancelled because transaction is not started",
5279 			(unsigned long long)off, (unsigned long long)len);
5280 		return -EIO;
5281 	}
5282 	/*
5283 	 * Since we account only one data block in transaction credits,
5284 	 * then it is impossible to cross a block boundary.
5285 	 */
5286 	if (sb->s_blocksize - offset < len) {
5287 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5288 			" cancelled because not block aligned",
5289 			(unsigned long long)off, (unsigned long long)len);
5290 		return -EIO;
5291 	}
5292 
5293 	bh = ext4_bread(handle, inode, blk, 1, &err);
5294 	if (!bh)
5295 		goto out;
5296 	err = ext4_journal_get_write_access(handle, bh);
5297 	if (err) {
5298 		brelse(bh);
5299 		goto out;
5300 	}
5301 	lock_buffer(bh);
5302 	memcpy(bh->b_data+offset, data, len);
5303 	flush_dcache_page(bh->b_page);
5304 	unlock_buffer(bh);
5305 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5306 	brelse(bh);
5307 out:
5308 	if (err)
5309 		return err;
5310 	if (inode->i_size < off + len) {
5311 		i_size_write(inode, off + len);
5312 		EXT4_I(inode)->i_disksize = inode->i_size;
5313 		ext4_mark_inode_dirty(handle, inode);
5314 	}
5315 	return len;
5316 }
5317 
5318 #endif
5319 
5320 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5321 		       const char *dev_name, void *data)
5322 {
5323 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5324 }
5325 
5326 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5327 static inline void register_as_ext2(void)
5328 {
5329 	int err = register_filesystem(&ext2_fs_type);
5330 	if (err)
5331 		printk(KERN_WARNING
5332 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5333 }
5334 
5335 static inline void unregister_as_ext2(void)
5336 {
5337 	unregister_filesystem(&ext2_fs_type);
5338 }
5339 
5340 static inline int ext2_feature_set_ok(struct super_block *sb)
5341 {
5342 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5343 		return 0;
5344 	if (sb->s_flags & MS_RDONLY)
5345 		return 1;
5346 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5347 		return 0;
5348 	return 1;
5349 }
5350 #else
5351 static inline void register_as_ext2(void) { }
5352 static inline void unregister_as_ext2(void) { }
5353 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5354 #endif
5355 
5356 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5357 static inline void register_as_ext3(void)
5358 {
5359 	int err = register_filesystem(&ext3_fs_type);
5360 	if (err)
5361 		printk(KERN_WARNING
5362 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5363 }
5364 
5365 static inline void unregister_as_ext3(void)
5366 {
5367 	unregister_filesystem(&ext3_fs_type);
5368 }
5369 
5370 static inline int ext3_feature_set_ok(struct super_block *sb)
5371 {
5372 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5373 		return 0;
5374 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5375 		return 0;
5376 	if (sb->s_flags & MS_RDONLY)
5377 		return 1;
5378 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5379 		return 0;
5380 	return 1;
5381 }
5382 #else
5383 static inline void register_as_ext3(void) { }
5384 static inline void unregister_as_ext3(void) { }
5385 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5386 #endif
5387 
5388 static struct file_system_type ext4_fs_type = {
5389 	.owner		= THIS_MODULE,
5390 	.name		= "ext4",
5391 	.mount		= ext4_mount,
5392 	.kill_sb	= kill_block_super,
5393 	.fs_flags	= FS_REQUIRES_DEV,
5394 };
5395 MODULE_ALIAS_FS("ext4");
5396 
5397 static int __init ext4_init_feat_adverts(void)
5398 {
5399 	struct ext4_features *ef;
5400 	int ret = -ENOMEM;
5401 
5402 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5403 	if (!ef)
5404 		goto out;
5405 
5406 	ef->f_kobj.kset = ext4_kset;
5407 	init_completion(&ef->f_kobj_unregister);
5408 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5409 				   "features");
5410 	if (ret) {
5411 		kfree(ef);
5412 		goto out;
5413 	}
5414 
5415 	ext4_feat = ef;
5416 	ret = 0;
5417 out:
5418 	return ret;
5419 }
5420 
5421 static void ext4_exit_feat_adverts(void)
5422 {
5423 	kobject_put(&ext4_feat->f_kobj);
5424 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5425 	kfree(ext4_feat);
5426 }
5427 
5428 /* Shared across all ext4 file systems */
5429 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5430 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5431 
5432 static int __init ext4_init_fs(void)
5433 {
5434 	int i, err;
5435 
5436 	ext4_li_info = NULL;
5437 	mutex_init(&ext4_li_mtx);
5438 
5439 	/* Build-time check for flags consistency */
5440 	ext4_check_flag_values();
5441 
5442 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5443 		mutex_init(&ext4__aio_mutex[i]);
5444 		init_waitqueue_head(&ext4__ioend_wq[i]);
5445 	}
5446 
5447 	err = ext4_init_es();
5448 	if (err)
5449 		return err;
5450 
5451 	err = ext4_init_pageio();
5452 	if (err)
5453 		goto out7;
5454 
5455 	err = ext4_init_system_zone();
5456 	if (err)
5457 		goto out6;
5458 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5459 	if (!ext4_kset) {
5460 		err = -ENOMEM;
5461 		goto out5;
5462 	}
5463 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5464 
5465 	err = ext4_init_feat_adverts();
5466 	if (err)
5467 		goto out4;
5468 
5469 	err = ext4_init_mballoc();
5470 	if (err)
5471 		goto out3;
5472 
5473 	err = ext4_init_xattr();
5474 	if (err)
5475 		goto out2;
5476 	err = init_inodecache();
5477 	if (err)
5478 		goto out1;
5479 	register_as_ext3();
5480 	register_as_ext2();
5481 	err = register_filesystem(&ext4_fs_type);
5482 	if (err)
5483 		goto out;
5484 
5485 	return 0;
5486 out:
5487 	unregister_as_ext2();
5488 	unregister_as_ext3();
5489 	destroy_inodecache();
5490 out1:
5491 	ext4_exit_xattr();
5492 out2:
5493 	ext4_exit_mballoc();
5494 out3:
5495 	ext4_exit_feat_adverts();
5496 out4:
5497 	if (ext4_proc_root)
5498 		remove_proc_entry("fs/ext4", NULL);
5499 	kset_unregister(ext4_kset);
5500 out5:
5501 	ext4_exit_system_zone();
5502 out6:
5503 	ext4_exit_pageio();
5504 out7:
5505 	ext4_exit_es();
5506 
5507 	return err;
5508 }
5509 
5510 static void __exit ext4_exit_fs(void)
5511 {
5512 	ext4_destroy_lazyinit_thread();
5513 	unregister_as_ext2();
5514 	unregister_as_ext3();
5515 	unregister_filesystem(&ext4_fs_type);
5516 	destroy_inodecache();
5517 	ext4_exit_xattr();
5518 	ext4_exit_mballoc();
5519 	ext4_exit_feat_adverts();
5520 	remove_proc_entry("fs/ext4", NULL);
5521 	kset_unregister(ext4_kset);
5522 	ext4_exit_system_zone();
5523 	ext4_exit_pageio();
5524 	ext4_exit_es();
5525 }
5526 
5527 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5528 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5529 MODULE_LICENSE("GPL");
5530 module_init(ext4_init_fs)
5531 module_exit(ext4_exit_fs)
5532